1 /*
   2  * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_RUNTIME_GLOBALS_HPP
  26 #define SHARE_RUNTIME_GLOBALS_HPP
  27 
  28 #include "compiler/compiler_globals_pd.hpp"
  29 #include "runtime/globals_shared.hpp"
  30 #include "utilities/align.hpp"
  31 #include "utilities/globalDefinitions.hpp"
  32 #include "utilities/macros.hpp"
  33 #include CPU_HEADER(globals)
  34 #include OS_HEADER(globals)
  35 #include OS_CPU_HEADER(globals)
  36 
  37 // develop flags are settable / visible only during development and are constant in the PRODUCT version
  38 // product flags are always settable / visible
  39 // notproduct flags are settable / visible only during development and are not declared in the PRODUCT version
  40 // develop_pd/product_pd flags are the same as develop/product, except that their default values
  41 // are specified in platform-dependent header files.
  42 
  43 // Flags must be declared with the following number of parameters:
  44 // non-pd flags:
  45 //    (type, name, default_value, doc), or
  46 //    (type, name, default_value, extra_attrs, doc)
  47 // pd flags:
  48 //    (type, name, doc), or
  49 //    (type, name, extra_attrs, doc)
  50 
  51 // A flag must be declared with one of the following types:
  52 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t.
  53 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used
  54 // only in this file, because the macrology requires single-token type names.
  55 
  56 // The optional extra_attrs parameter may have one of the following values:
  57 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used
  58 // only with product/product_pd flags.
  59 //
  60 // DIAGNOSTIC options are not meant for VM tuning or for product modes.
  61 //    They are to be used for VM quality assurance or field diagnosis
  62 //    of VM bugs.  They are hidden so that users will not be encouraged to
  63 //    try them as if they were VM ordinary execution options.  However, they
  64 //    are available in the product version of the VM.  Under instruction
  65 //    from support engineers, VM customers can turn them on to collect
  66 //    diagnostic information about VM problems.  To use a VM diagnostic
  67 //    option, you must first specify +UnlockDiagnosticVMOptions.
  68 //    (This master switch also affects the behavior of -Xprintflags.)
  69 //
  70 // EXPERIMENTAL flags are in support of features that may not be
  71 //    an officially supported part of a product, but may be available
  72 //    for experimenting with. They could, for example, be performance
  73 //    features that may not have undergone full or rigorous QA, but which may
  74 //    help performance in some cases and released for experimentation
  75 //    by the community of users and developers. This flag also allows one to
  76 //    be able to build a fully supported product that nonetheless also
  77 //    ships with some unsupported, lightly tested, experimental features.
  78 //    Refer to the documentation of any products using this code for details
  79 //    on support and fitness for production.
  80 //    Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
  81 //    UnlockExperimentalVMOptions flag, which allows the control and
  82 //    modification of the experimental flags.
  83 //
  84 // Nota bene: neither diagnostic nor experimental options should be used casually,
  85 //    Refer to the documentation of any products using this code for details.
  86 //
  87 // MANAGEABLE flags are writeable external product flags.
  88 //    They are dynamically writeable through the JDK management interface
  89 //    (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole.
  90 //    These flags are external exported interface (see CCC).  The list of
  91 //    manageable flags can be queried programmatically through the management
  92 //    interface.
  93 //
  94 //    A flag can be made as "manageable" only if
  95 //    - the flag is defined in a CCC as an external exported interface.
  96 //    - the VM implementation supports dynamic setting of the flag.
  97 //      This implies that the VM must *always* query the flag variable
  98 //      and not reuse state related to the flag state at any given time.
  99 //    - you want the flag to be queried programmatically by the customers.
 100 //
 101 
 102 //
 103 // range is a macro that will expand to min and max arguments for range
 104 //    checking code if provided - see jvmFlagLimit.hpp
 105 //
 106 // constraint is a macro that will expand to custom function call
 107 //    for constraint checking if provided - see jvmFlagLimit.hpp
 108 
 109 // Default and minimum StringTable and SymbolTable size values
 110 // Must be powers of 2
 111 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536);
 112 const size_t minimumStringTableSize = 128;
 113 const size_t defaultSymbolTableSize = 32768; // 2^15
 114 const size_t minimumSymbolTableSize = 1024;
 115 
 116 #ifdef _LP64
 117 #define LP64_RUNTIME_FLAGS(develop,                                         \
 118                            develop_pd,                                      \
 119                            product,                                         \
 120                            product_pd,                                      \
 121                            notproduct,                                      \
 122                            range,                                           \
 123                            constraint)                                      \
 124                                                                             \
 125   product(bool, UseCompressedOops, false,                                   \
 126           "Use 32-bit object references in 64-bit VM. "                     \
 127           "lp64_product means flag is always constant in 32 bit VM")        \
 128                                                                             \
 129   product(bool, UseCompressedClassPointers, false,                          \
 130           "Use 32-bit class pointers in 64-bit VM. "                        \
 131           "lp64_product means flag is always constant in 32 bit VM")        \
 132                                                                             \
 133   product(intx, ObjectAlignmentInBytes, 8,                                  \
 134           "Default object alignment in bytes, 8 is minimum")                \
 135           range(8, 256)                                                     \
 136           constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
 137 
 138 #else
 139 // !_LP64
 140 
 141 #define LP64_RUNTIME_FLAGS(develop,                                         \
 142                            develop_pd,                                      \
 143                            product,                                         \
 144                            product_pd,                                      \
 145                            notproduct,                                      \
 146                            range,                                           \
 147                            constraint)
 148 const bool UseCompressedOops = false;
 149 const bool UseCompressedClassPointers = false;
 150 const intx ObjectAlignmentInBytes = 8;
 151 
 152 #endif // _LP64
 153 
 154 #define RUNTIME_FLAGS(develop,                                              \
 155                       develop_pd,                                           \
 156                       product,                                              \
 157                       product_pd,                                           \
 158                       notproduct,                                           \
 159                       range,                                                \
 160                       constraint)                                           \
 161                                                                             \
 162   notproduct(bool, CheckCompressedOops, true,                               \
 163           "Generate checks in encoding/decoding code in debug VM")          \
 164                                                                             \
 165   product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17),                        \
 166           "Heap allocation steps through preferred address regions to find" \
 167           " where it can allocate the heap. Number of steps to take per "   \
 168           "region.")                                                        \
 169           range(1, max_uintx)                                               \
 170                                                                             \
 171   product(uint, HandshakeTimeout, 0, DIAGNOSTIC,                            \
 172           "If nonzero set a timeout in milliseconds for handshakes")        \
 173                                                                             \
 174   product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL,                \
 175           "Force safe construction, as if all fields are final.")           \
 176                                                                             \
 177   product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC,         \
 178           "Enable normal processing of flags relating to field diagnostics")\
 179                                                                             \
 180   product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL,           \
 181           "Enable normal processing of flags relating to experimental "     \
 182           "features")                                                       \
 183                                                                             \
 184   product(bool, JavaMonitorsInStackTrace, true,                             \
 185           "Print information about Java monitor locks when the stacks are " \
 186           "dumped")                                                         \
 187                                                                             \
 188   product_pd(bool, UseLargePages,                                           \
 189           "Use large page memory")                                          \
 190                                                                             \
 191   product_pd(bool, UseLargePagesIndividualAllocation,                       \
 192           "Allocate large pages individually for better affinity")          \
 193                                                                             \
 194   develop(bool, LargePagesIndividualAllocationInjectError, false,           \
 195           "Fail large pages individual allocation")                         \
 196                                                                             \
 197   product(bool, UseNUMA, false,                                             \
 198           "Use NUMA if available")                                          \
 199                                                                             \
 200   product(bool, UseNUMAInterleaving, false,                                 \
 201           "Interleave memory across NUMA nodes if available")               \
 202                                                                             \
 203   product(size_t, NUMAInterleaveGranularity, 2*M,                           \
 204           "Granularity to use for NUMA interleaving on Windows OS")         \
 205           constraint(NUMAInterleaveGranularityConstraintFunc, AtParse)      \
 206                                                                             \
 207   product(uintx, NUMAChunkResizeWeight, 20,                                 \
 208           "Percentage (0-100) used to weight the current sample when "      \
 209           "computing exponentially decaying average for "                   \
 210           "AdaptiveNUMAChunkSizing")                                        \
 211           range(0, 100)                                                     \
 212                                                                             \
 213   product(size_t, NUMASpaceResizeRate, 1*G,                                 \
 214           "Do not reallocate more than this amount per collection")         \
 215           range(0, max_uintx)                                               \
 216                                                                             \
 217   product(bool, UseAdaptiveNUMAChunkSizing, true,                           \
 218           "Enable adaptive chunk sizing for NUMA")                          \
 219                                                                             \
 220   product(bool, NUMAStats, false,                                           \
 221           "Print NUMA stats in detailed heap information")                  \
 222                                                                             \
 223   product(uintx, NUMAPageScanRate, 256,                                     \
 224           "Maximum number of pages to include in the page scan procedure")  \
 225           range(0, max_uintx)                                               \
 226                                                                             \
 227   product(bool, UseAES, false,                                              \
 228           "Control whether AES instructions are used when available")       \
 229                                                                             \
 230   product(bool, UseFMA, false,                                              \
 231           "Control whether FMA instructions are used when available")       \
 232                                                                             \
 233   product(bool, UseSHA, false,                                              \
 234           "Control whether SHA instructions are used when available")       \
 235                                                                             \
 236   product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC,                      \
 237           "Use intrinsics for GHASH versions of crypto")                    \
 238                                                                             \
 239   product(bool, UseBASE64Intrinsics, false,                                 \
 240           "Use intrinsics for java.util.Base64")                            \
 241                                                                             \
 242   product(size_t, LargePageSizeInBytes, 0,                                  \
 243           "Maximum large page size used (0 will use the default large "     \
 244           "page size for the environment as the maximum)")                  \
 245           range(0, max_uintx)                                               \
 246                                                                             \
 247   product(size_t, LargePageHeapSizeThreshold, 128*M,                        \
 248           "Use large pages if maximum heap is at least this big")           \
 249           range(0, max_uintx)                                               \
 250                                                                             \
 251   product(bool, ForceTimeHighResolution, false,                             \
 252           "Using high time resolution (for Win32 only)")                    \
 253                                                                             \
 254   develop(bool, TracePcPatching, false,                                     \
 255           "Trace usage of frame::patch_pc")                                 \
 256                                                                             \
 257   develop(bool, TraceRelocator, false,                                      \
 258           "Trace the bytecode relocator")                                   \
 259                                                                             \
 260                                                                             \
 261   product(bool, SafepointALot, false, DIAGNOSTIC,                           \
 262           "Generate a lot of safepoints. This works with "                  \
 263           "GuaranteedSafepointInterval")                                    \
 264                                                                             \
 265   product(bool, HandshakeALot, false, DIAGNOSTIC,                           \
 266           "Generate a lot of handshakes. This works with "                  \
 267           "GuaranteedSafepointInterval")                                    \
 268                                                                             \
 269   product_pd(bool, BackgroundCompilation,                                   \
 270           "A thread requesting compilation is not blocked during "          \
 271           "compilation")                                                    \
 272                                                                             \
 273   product(bool, MethodFlushing, true,                                       \
 274           "Reclamation of zombie and not-entrant methods")                  \
 275                                                                             \
 276   develop(bool, VerifyStack, false,                                         \
 277           "Verify stack of each thread when it is entering a runtime call") \
 278                                                                             \
 279   product(bool, ForceUnreachable, false, DIAGNOSTIC,                        \
 280           "Make all non code cache addresses to be unreachable by "         \
 281           "forcing use of 64bit literal fixups")                            \
 282                                                                             \
 283   develop(bool, TraceDerivedPointers, false,                                \
 284           "Trace traversal of derived pointers on stack")                   \
 285                                                                             \
 286   notproduct(bool, TraceCodeBlobStacks, false,                              \
 287           "Trace stack-walk of codeblobs")                                  \
 288                                                                             \
 289   notproduct(bool, PrintRewrites, false,                                    \
 290           "Print methods that are being rewritten")                         \
 291                                                                             \
 292   product(bool, UseInlineCaches, true,                                      \
 293           "Use Inline Caches for virtual calls ")                           \
 294                                                                             \
 295   product(size_t, InlineCacheBufferSize, 10*K, EXPERIMENTAL,                \
 296           "InlineCacheBuffer size")                                         \
 297                                                                             \
 298   product(bool, InlineArrayCopy, true, DIAGNOSTIC,                          \
 299           "Inline arraycopy native that is known to be part of "            \
 300           "base library DLL")                                               \
 301                                                                             \
 302   product(bool, InlineObjectHash, true, DIAGNOSTIC,                         \
 303           "Inline Object::hashCode() native that is known to be part "      \
 304           "of base library DLL")                                            \
 305                                                                             \
 306   product(bool, InlineNatives, true, DIAGNOSTIC,                            \
 307           "Inline natives that are known to be part of base library DLL")   \
 308                                                                             \
 309   product(bool, InlineMathNatives, true, DIAGNOSTIC,                        \
 310           "Inline SinD, CosD, etc.")                                        \
 311                                                                             \
 312   product(bool, InlineClassNatives, true, DIAGNOSTIC,                       \
 313           "Inline Class.isInstance, etc")                                   \
 314                                                                             \
 315   product(bool, InlineThreadNatives, true, DIAGNOSTIC,                      \
 316           "Inline Thread.currentThread, etc")                               \
 317                                                                             \
 318   product(bool, InlineUnsafeOps, true, DIAGNOSTIC,                          \
 319           "Inline memory ops (native methods) from Unsafe")                 \
 320                                                                             \
 321   product(bool, CriticalJNINatives, false,                                  \
 322           "(Deprecated) Check for critical JNI entry points")               \
 323                                                                             \
 324   product(bool, UseAESIntrinsics, false, DIAGNOSTIC,                        \
 325           "Use intrinsics for AES versions of crypto")                      \
 326                                                                             \
 327   product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC,                     \
 328           "Use intrinsics for the paralleled version of AES/CTR crypto")    \
 329                                                                             \
 330   product(bool, UseMD5Intrinsics, false, DIAGNOSTIC,                        \
 331           "Use intrinsics for MD5 crypto hash function")                    \
 332                                                                             \
 333   product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC,                       \
 334           "Use intrinsics for SHA-1 crypto hash function. "                 \
 335           "Requires that UseSHA is enabled.")                               \
 336                                                                             \
 337   product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC,                     \
 338           "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. "  \
 339           "Requires that UseSHA is enabled.")                               \
 340                                                                             \
 341   product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC,                     \
 342           "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. "  \
 343           "Requires that UseSHA is enabled.")                               \
 344                                                                             \
 345   product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC,                       \
 346           "Use intrinsics for SHA3 crypto hash function. "                  \
 347           "Requires that UseSHA is enabled.")                               \
 348                                                                             \
 349   product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC,                      \
 350           "use intrinsics for java.util.zip.CRC32")                         \
 351                                                                             \
 352   product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC,                     \
 353           "use intrinsics for java.util.zip.CRC32C")                        \
 354                                                                             \
 355   product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC,                    \
 356           "use intrinsics for java.util.zip.Adler32")                       \
 357                                                                             \
 358   product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC,          \
 359           "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
 360                                                                             \
 361   product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC,                    \
 362           "Enables intrinsification of Math.copySign")                      \
 363                                                                             \
 364   product(bool, UseSignumIntrinsic, false, DIAGNOSTIC,                      \
 365           "Enables intrinsification of Math.signum")                        \
 366                                                                             \
 367   product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC,                      \
 368          "do not expand intrinsics whose (internal) names appear here")     \
 369          constraint(DisableIntrinsicConstraintFunc,AfterErgo)               \
 370                                                                             \
 371   product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC,                      \
 372          "Control intrinsics using a list of +/- (internal) names, "        \
 373          "separated by commas")                                             \
 374          constraint(ControlIntrinsicConstraintFunc,AfterErgo)               \
 375                                                                             \
 376   develop(bool, TraceCallFixup, false,                                      \
 377           "Trace all call fixups")                                          \
 378                                                                             \
 379   develop(bool, DeoptimizeALot, false,                                      \
 380           "Deoptimize at every exit from the runtime system")               \
 381                                                                             \
 382   notproduct(ccstrlist, DeoptimizeOnlyAt, "",                               \
 383           "A comma separated list of bcis to deoptimize at")                \
 384                                                                             \
 385   develop(bool, DeoptimizeRandom, false,                                    \
 386           "Deoptimize random frames on random exit from the runtime system")\
 387                                                                             \
 388   notproduct(bool, ZombieALot, false,                                       \
 389           "Create zombies (non-entrant) at exit from the runtime system")   \
 390                                                                             \
 391   notproduct(bool, WalkStackALot, false,                                    \
 392           "Trace stack (no print) at every exit from the runtime system")   \
 393                                                                             \
 394   develop(bool, DeoptimizeObjectsALot, false,                               \
 395           "For testing purposes concurrent threads revert optimizations "   \
 396           "based on escape analysis at intervals given with "               \
 397           "DeoptimizeObjectsALotInterval=n. The thread count is given "     \
 398           "with DeoptimizeObjectsALotThreadCountSingle and "                \
 399           "DeoptimizeObjectsALotThreadCountAll.")                           \
 400                                                                             \
 401   develop(uint64_t, DeoptimizeObjectsALotInterval, 5,                       \
 402           "Interval for DeoptimizeObjectsALot.")                            \
 403           range(0, max_jlong)                                               \
 404                                                                             \
 405   develop(int, DeoptimizeObjectsALotThreadCountSingle, 1,                   \
 406           "The number of threads that revert optimizations based on "       \
 407           "escape analysis for a single thread if DeoptimizeObjectsALot "   \
 408           "is enabled. The target thread is selected round robin." )        \
 409           range(0, max_jint)                                                \
 410                                                                             \
 411   develop(int, DeoptimizeObjectsALotThreadCountAll, 1,                      \
 412           "The number of threads that revert optimizations based on "       \
 413           "escape analysis for all threads if DeoptimizeObjectsALot "       \
 414           "is enabled." )                                                   \
 415           range(0, max_jint)                                                \
 416                                                                             \
 417   notproduct(bool, VerifyLastFrame, false,                                  \
 418           "Verify oops on last frame on entry to VM")                       \
 419                                                                             \
 420   product(bool, SafepointTimeout, false,                                    \
 421           "Time out and warn or fail after SafepointTimeoutDelay "          \
 422           "milliseconds if failed to reach safepoint")                      \
 423                                                                             \
 424   product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC,               \
 425           "Abort upon failure to reach safepoint (see SafepointTimeout)")   \
 426                                                                             \
 427   product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC,             \
 428           "Abort upon failure to complete VM operation promptly")           \
 429                                                                             \
 430   product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC,         \
 431           "Delay in milliseconds for option AbortVMOnVMOperationTimeout")   \
 432           range(0, max_intx)                                                \
 433                                                                             \
 434   product(bool, MaxFDLimit, true,                                           \
 435           "Bump the number of file descriptors to maximum (Unix only)")     \
 436                                                                             \
 437   product(bool, LogEvents, true, DIAGNOSTIC,                                \
 438           "Enable the various ring buffer event logs")                      \
 439                                                                             \
 440   product(uintx, LogEventsBufferEntries, 20, DIAGNOSTIC,                    \
 441           "Number of ring buffer event logs")                               \
 442           range(1, NOT_LP64(1*K) LP64_ONLY(1*M))                            \
 443                                                                             \
 444   product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC,               \
 445           "Enable the Java bytecode verifier for remote classes")           \
 446                                                                             \
 447   product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC,               \
 448           "Enable the Java bytecode verifier for local classes")            \
 449                                                                             \
 450   develop(bool, VerifyStackAtCalls, false,                                  \
 451           "Verify that the stack pointer is unchanged after calls")         \
 452                                                                             \
 453   develop(bool, TraceJavaAssertions, false,                                 \
 454           "Trace java language assertions")                                 \
 455                                                                             \
 456   notproduct(bool, VerifyCodeCache, false,                                  \
 457           "Verify code cache on memory allocation/deallocation")            \
 458                                                                             \
 459   develop(bool, UseMallocOnly, false,                                       \
 460           "Use only malloc/free for allocation (no resource area/arena)")   \
 461                                                                             \
 462   develop(bool, ZapResourceArea, trueInDebug,                               \
 463           "Zap freed resource/arena space")                                 \
 464                                                                             \
 465   notproduct(bool, ZapVMHandleArea, trueInDebug,                            \
 466           "Zap freed VM handle space")                                      \
 467                                                                             \
 468   notproduct(bool, ZapStackSegments, trueInDebug,                           \
 469           "Zap allocated/freed stack segments")                             \
 470                                                                             \
 471   develop(bool, ZapUnusedHeapArea, trueInDebug,                             \
 472           "Zap unused heap space")                                          \
 473                                                                             \
 474   develop(bool, CheckZapUnusedHeapArea, false,                              \
 475           "Check zapping of unused heap space")                             \
 476                                                                             \
 477   develop(bool, ZapFillerObjects, trueInDebug,                              \
 478           "Zap filler objects")                                             \
 479                                                                             \
 480   product(bool, ExecutingUnitTests, false,                                  \
 481           "Whether the JVM is running unit tests or not")                   \
 482                                                                             \
 483   develop(uintx, ErrorHandlerTest, 0,                                       \
 484           "If > 0, provokes an error after VM initialization; the value "   \
 485           "determines which error to provoke. See controlled_crash() "      \
 486           "in vmError.cpp.")                                                \
 487           range(0, 17)                                                      \
 488                                                                             \
 489   develop(uintx, TestCrashInErrorHandler, 0,                                \
 490           "If > 0, provokes an error inside VM error handler (a secondary " \
 491           "crash). see controlled_crash() in vmError.cpp")                  \
 492           range(0, 17)                                                      \
 493                                                                             \
 494   develop(bool, TestSafeFetchInErrorHandler, false   ,                      \
 495           "If true, tests SafeFetch inside error handler.")                 \
 496                                                                             \
 497   develop(bool, TestUnresponsiveErrorHandler, false,                        \
 498           "If true, simulates an unresponsive error handler.")              \
 499                                                                             \
 500   develop(bool, Verbose, false,                                             \
 501           "Print additional debugging information from other modes")        \
 502                                                                             \
 503   develop(bool, PrintMiscellaneous, false,                                  \
 504           "Print uncategorized debugging information (requires +Verbose)")  \
 505                                                                             \
 506   develop(bool, WizardMode, false,                                          \
 507           "Print much more debugging information")                          \
 508                                                                             \
 509   product(bool, ShowMessageBoxOnError, false,                               \
 510           "Keep process alive on VM fatal error")                           \
 511                                                                             \
 512   product(bool, CreateCoredumpOnCrash, true,                                \
 513           "Create core/mini dump on VM fatal error")                        \
 514                                                                             \
 515   product(uint64_t, ErrorLogTimeout, 2 * 60,                                \
 516           "Timeout, in seconds, to limit the time spent on writing an "     \
 517           "error log in case of a crash.")                                  \
 518           range(0, (uint64_t)max_jlong/1000)                                \
 519                                                                             \
 520   product(bool, SuppressFatalErrorMessage, false,                           \
 521           "Report NO fatal error message (avoid deadlock)")                 \
 522                                                                             \
 523   product(ccstrlist, OnError, "",                                           \
 524           "Run user-defined commands on fatal error; see VMError.cpp "      \
 525           "for examples")                                                   \
 526                                                                             \
 527   product(ccstrlist, OnOutOfMemoryError, "",                                \
 528           "Run user-defined commands on first java.lang.OutOfMemoryError "  \
 529           "thrown from JVM")                                                \
 530                                                                             \
 531   product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE,                    \
 532           "Dump heap to file before any major stop-the-world GC")           \
 533                                                                             \
 534   product(bool, HeapDumpAfterFullGC, false, MANAGEABLE,                     \
 535           "Dump heap to file after any major stop-the-world GC")            \
 536                                                                             \
 537   product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE,              \
 538           "Dump heap to file when java.lang.OutOfMemoryError is thrown "    \
 539           "from JVM")                                                       \
 540                                                                             \
 541   product(ccstr, HeapDumpPath, NULL, MANAGEABLE,                            \
 542           "When HeapDumpOnOutOfMemoryError is on, the path (filename or "   \
 543           "directory) of the dump file (defaults to java_pid<pid>.hprof "   \
 544           "in the working directory)")                                      \
 545                                                                             \
 546   product(intx, HeapDumpGzipLevel, 0, MANAGEABLE,                           \
 547           "When HeapDumpOnOutOfMemoryError is on, the gzip compression "    \
 548           "level of the dump file. 0 (the default) disables gzip "          \
 549           "compression. Otherwise the level must be between 1 and 9.")      \
 550           range(0, 9)                                                       \
 551                                                                             \
 552   product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
 553           "Native memory tracking options")                                 \
 554                                                                             \
 555   product(bool, PrintNMTStatistics, false, DIAGNOSTIC,                      \
 556           "Print native memory tracking summary data if it is on")          \
 557                                                                             \
 558   product(bool, LogCompilation, false, DIAGNOSTIC,                          \
 559           "Log compilation activity in detail to LogFile")                  \
 560                                                                             \
 561   product(bool, PrintCompilation, false,                                    \
 562           "Print compilations")                                             \
 563                                                                             \
 564   product(intx, RepeatCompilation, 0, DIAGNOSTIC,                           \
 565           "Repeat compilation without installing code (number of times)")   \
 566           range(0, max_jint)                                                \
 567                                                                             \
 568   product(bool, PrintExtendedThreadInfo, false,                             \
 569           "Print more information in thread dump")                          \
 570                                                                             \
 571   product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC,                         \
 572           "0: do not allow scavengable oops in the code cache; "            \
 573           "1: allow scavenging from the code cache; "                       \
 574           "2: emit as many constants as the compiler can see")              \
 575           range(0, 2)                                                       \
 576                                                                             \
 577   product(bool, AlwaysRestoreFPU, false,                                    \
 578           "Restore the FPU control word after every JNI call (expensive)")  \
 579                                                                             \
 580   product(bool, PrintCompilation2, false, DIAGNOSTIC,                       \
 581           "Print additional statistics per compilation")                    \
 582                                                                             \
 583   product(bool, PrintAdapterHandlers, false, DIAGNOSTIC,                    \
 584           "Print code generated for i2c/c2i adapters")                      \
 585                                                                             \
 586   product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC,                \
 587           "Verify that i2c/c2i adapters are called properly")               \
 588                                                                             \
 589   develop(bool, VerifyAdapterSharing, false,                                \
 590           "Verify that the code for shared adapters is the equivalent")     \
 591                                                                             \
 592   product(bool, PrintAssembly, false, DIAGNOSTIC,                           \
 593           "Print assembly code (using external disassembler.so)")           \
 594                                                                             \
 595   product(ccstr, PrintAssemblyOptions, NULL, DIAGNOSTIC,                    \
 596           "Print options string passed to disassembler.so")                 \
 597                                                                             \
 598   notproduct(bool, PrintNMethodStatistics, false,                           \
 599           "Print a summary statistic for the generated nmethods")           \
 600                                                                             \
 601   product(bool, PrintNMethods, false, DIAGNOSTIC,                           \
 602           "Print assembly code for nmethods when generated")                \
 603                                                                             \
 604   product(bool, PrintNativeNMethods, false, DIAGNOSTIC,                     \
 605           "Print assembly code for native nmethods when generated")         \
 606                                                                             \
 607   develop(bool, PrintDebugInfo, false,                                      \
 608           "Print debug information for all nmethods when generated")        \
 609                                                                             \
 610   develop(bool, PrintRelocations, false,                                    \
 611           "Print relocation information for all nmethods when generated")   \
 612                                                                             \
 613   develop(bool, PrintDependencies, false,                                   \
 614           "Print dependency information for all nmethods when generated")   \
 615                                                                             \
 616   develop(bool, PrintExceptionHandlers, false,                              \
 617           "Print exception handler tables for all nmethods when generated") \
 618                                                                             \
 619   develop(bool, StressCompiledExceptionHandlers, false,                     \
 620           "Exercise compiled exception handlers")                           \
 621                                                                             \
 622   develop(bool, InterceptOSException, false,                                \
 623           "Start debugger when an implicit OS (e.g. NULL) "                 \
 624           "exception happens")                                              \
 625                                                                             \
 626   product(bool, PrintCodeCache, false,                                      \
 627           "Print the code cache memory usage when exiting")                 \
 628                                                                             \
 629   develop(bool, PrintCodeCache2, false,                                     \
 630           "Print detailed usage information on the code cache when exiting")\
 631                                                                             \
 632   product(bool, PrintCodeCacheOnCompilation, false,                         \
 633           "Print the code cache memory usage each time a method is "        \
 634           "compiled")                                                       \
 635                                                                             \
 636   product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC,                  \
 637           "Print code heap usage statistics on exit and on full condition") \
 638                                                                             \
 639   product(bool, PrintStubCode, false, DIAGNOSTIC,                           \
 640           "Print generated stub code")                                      \
 641                                                                             \
 642   product(bool, StackTraceInThrowable, true,                                \
 643           "Collect backtrace in throwable when exception happens")          \
 644                                                                             \
 645   product(bool, OmitStackTraceInFastThrow, true,                            \
 646           "Omit backtraces for some 'hot' exceptions in optimized code")    \
 647                                                                             \
 648   product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE,       \
 649           "Show exception messages from RuntimeExceptions that contain "    \
 650           "snippets of the failing code. Disable this to improve privacy.") \
 651                                                                             \
 652   product(bool, PrintWarnings, true,                                        \
 653           "Print JVM warnings to output stream")                            \
 654                                                                             \
 655   product(bool, RegisterFinalizersAtInit, true,                             \
 656           "Register finalizable objects at end of Object.<init> or "        \
 657           "after allocation")                                               \
 658                                                                             \
 659   develop(bool, RegisterReferences, true,                                   \
 660           "Tell whether the VM should register soft/weak/final/phantom "    \
 661           "references")                                                     \
 662                                                                             \
 663   develop(bool, PrintCodeCacheExtension, false,                             \
 664           "Print extension of code cache")                                  \
 665                                                                             \
 666   develop(bool, UsePrivilegedStack, true,                                   \
 667           "Enable the security JVM functions")                              \
 668                                                                             \
 669   product(bool, ClassUnloading, true,                                       \
 670           "Do unloading of classes")                                        \
 671                                                                             \
 672   product(bool, ClassUnloadingWithConcurrentMark, true,                     \
 673           "Do unloading of classes with a concurrent marking cycle")        \
 674                                                                             \
 675   notproduct(bool, PrintSystemDictionaryAtExit, false,                      \
 676           "Print the system dictionary at exit")                            \
 677                                                                             \
 678   notproduct(bool, PrintClassLoaderDataGraphAtExit, false,                  \
 679           "Print the class loader data graph at exit")                      \
 680                                                                             \
 681   product(bool, DynamicallyResizeSystemDictionaries, true, DIAGNOSTIC,      \
 682           "Dynamically resize system dictionaries as needed")               \
 683                                                                             \
 684   product(bool, AlwaysLockClassLoader, false,                               \
 685           "(Deprecated) Require the VM to acquire the class loader lock "   \
 686           "before calling loadClass() even for class loaders registering "  \
 687           "as parallel capable")                                            \
 688                                                                             \
 689   product(bool, AllowParallelDefineClass, false,                            \
 690           "Allow parallel defineClass requests for class loaders "          \
 691           "registering as parallel capable")                                \
 692                                                                             \
 693   product_pd(bool, DontYieldALot,                                           \
 694           "Throw away obvious excess yield calls")                          \
 695                                                                             \
 696   product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL,     \
 697                "Disable the use of stack guard pages if the JVM is loaded " \
 698                "on the primordial process thread")                          \
 699                                                                             \
 700   /* notice: the max range value here is max_jint, not max_intx  */         \
 701   /* because of overflow issue                                   */         \
 702   product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC,                    \
 703           "Async deflate idle monitors every so many milliseconds when "    \
 704           "MonitorUsedDeflationThreshold is exceeded (0 is off).")          \
 705           range(0, max_jint)                                                \
 706                                                                             \
 707   /* notice: the max range value here is max_jint, not max_intx  */         \
 708   /* because of overflow issue                                   */         \
 709   product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC,        \
 710           "Async deflate idle monitors every so many milliseconds even "    \
 711           "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
 712           range(0, max_jint)                                                \
 713                                                                             \
 714   product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC,           \
 715           "Used to estimate a variable ceiling based on number of threads " \
 716           "for use with MonitorUsedDeflationThreshold (0 is off).")         \
 717           range(0, max_uintx)                                               \
 718                                                                             \
 719   /* notice: the max range value here is max_jint, not max_intx  */         \
 720   /* because of overflow issue                                   */         \
 721   product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC,                   \
 722           "The maximum number of monitors to deflate, unlink and delete "   \
 723           "at one time (minimum is 1024).")                      \
 724           range(1024, max_jint)                                             \
 725                                                                             \
 726   product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC,              \
 727           "Percentage of used monitors before triggering deflation (0 is "  \
 728           "off). The check is performed on GuaranteedSafepointInterval, "   \
 729           "AsyncDeflationInterval or GuaranteedAsyncDeflationInterval, "    \
 730           "whichever is lower.")                                            \
 731           range(0, 100)                                                     \
 732                                                                             \
 733   product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC,                \
 734           "Max number of no progress async deflation attempts to tolerate " \
 735           "before adjusting the in_use_list_ceiling up (0 is off).")        \
 736           range(0, max_uintx)                                               \
 737                                                                             \
 738   product(intx, hashCode, 5, EXPERIMENTAL,                                  \
 739                "(Unstable) select hashCode generation algorithm")           \
 740                                                                             \
 741   product(bool, FilterSpuriousWakeups, true,                                \
 742           "When true prevents OS-level spurious, or premature, wakeups "    \
 743           "from Object.wait (Ignored for Windows)")                         \
 744                                                                             \
 745   product(bool, ReduceSignalUsage, false,                                   \
 746           "Reduce the use of OS signals in Java and/or the VM")             \
 747                                                                             \
 748   develop(bool, LoadLineNumberTables, true,                                 \
 749           "Tell whether the class file parser loads line number tables")    \
 750                                                                             \
 751   develop(bool, LoadLocalVariableTables, true,                              \
 752           "Tell whether the class file parser loads local variable tables") \
 753                                                                             \
 754   develop(bool, LoadLocalVariableTypeTables, true,                          \
 755           "Tell whether the class file parser loads local variable type"    \
 756           "tables")                                                         \
 757                                                                             \
 758   product(bool, AllowUserSignalHandlers, false,                             \
 759           "Application will install primary signal handlers for the JVM "   \
 760           "(Unix only)")                                                    \
 761                                                                             \
 762   product(bool, UseSignalChaining, true,                                    \
 763           "Use signal-chaining to invoke signal handlers installed "        \
 764           "by the application (Unix only)")                                 \
 765                                                                             \
 766   product(bool, RestoreMXCSROnJNICalls, false,                              \
 767           "Restore MXCSR when returning from JNI calls")                    \
 768                                                                             \
 769   product(bool, CheckJNICalls, false,                                       \
 770           "Verify all arguments to JNI calls")                              \
 771                                                                             \
 772   product(bool, UseFastJNIAccessors, true,                                  \
 773           "Use optimized versions of Get<Primitive>Field")                  \
 774                                                                             \
 775   product(intx, MaxJNILocalCapacity, 65536,                                 \
 776           "Maximum allowable local JNI handle capacity to "                 \
 777           "EnsureLocalCapacity() and PushLocalFrame(), "                    \
 778           "where <= 0 is unlimited, default: 65536")                        \
 779           range(min_intx, max_intx)                                         \
 780                                                                             \
 781   product(bool, EagerXrunInit, false,                                       \
 782           "Eagerly initialize -Xrun libraries; allows startup profiling, "  \
 783           "but not all -Xrun libraries may support the state of the VM "    \
 784           "at this time")                                                   \
 785                                                                             \
 786   product(bool, PreserveAllAnnotations, false,                              \
 787           "Preserve RuntimeInvisibleAnnotations as well "                   \
 788           "as RuntimeVisibleAnnotations")                                   \
 789                                                                             \
 790   develop(uintx, PreallocatedOutOfMemoryErrorCount, 4,                      \
 791           "Number of OutOfMemoryErrors preallocated with backtrace")        \
 792                                                                             \
 793   product(bool, UseXMMForArrayCopy, false,                                  \
 794           "Use SSE2 MOVQ instruction for Arraycopy")                        \
 795                                                                             \
 796   notproduct(bool, PrintFieldLayout, false,                                 \
 797           "Print field layout for each class")                              \
 798                                                                             \
 799   /* Need to limit the extent of the padding to reasonable size.          */\
 800   /* 8K is well beyond the reasonable HW cache line size, even with       */\
 801   /* aggressive prefetching, while still leaving the room for segregating */\
 802   /* among the distinct pages.                                            */\
 803   product(intx, ContendedPaddingWidth, 128,                                 \
 804           "How many bytes to pad the fields/classes marked @Contended with")\
 805           range(0, 8192)                                                    \
 806           constraint(ContendedPaddingWidthConstraintFunc,AfterErgo)         \
 807                                                                             \
 808   product(bool, EnableContended, true,                                      \
 809           "Enable @Contended annotation support")                           \
 810                                                                             \
 811   product(bool, RestrictContended, true,                                    \
 812           "Restrict @Contended to trusted classes")                         \
 813                                                                             \
 814   product(bool, UseBiasedLocking, false,                                    \
 815           "(Deprecated) Enable biased locking in JVM")                      \
 816                                                                             \
 817   product(intx, BiasedLockingStartupDelay, 0,                               \
 818           "(Deprecated) Number of milliseconds to wait before enabling "    \
 819           "biased locking")                                                 \
 820           range(0, (intx)(max_jint-(max_jint%PeriodicTask::interval_gran))) \
 821           constraint(BiasedLockingStartupDelayFunc,AfterErgo)               \
 822                                                                             \
 823   product(bool, PrintBiasedLockingStatistics, false, DIAGNOSTIC,            \
 824           "(Deprecated) Print statistics of biased locking in JVM")         \
 825                                                                             \
 826   product(intx, BiasedLockingBulkRebiasThreshold, 20,                       \
 827           "(Deprecated) Threshold of number of revocations per type to "    \
 828           "try to rebias all objects in the heap of that type")             \
 829           range(0, max_intx)                                                \
 830           constraint(BiasedLockingBulkRebiasThresholdFunc,AfterErgo)        \
 831                                                                             \
 832   product(intx, BiasedLockingBulkRevokeThreshold, 40,                       \
 833           "(Deprecated) Threshold of number of revocations per type to "    \
 834           "permanently revoke biases of all objects in the heap of that "   \
 835           "type")                                                           \
 836           range(0, max_intx)                                                \
 837           constraint(BiasedLockingBulkRevokeThresholdFunc,AfterErgo)        \
 838                                                                             \
 839   product(intx, BiasedLockingDecayTime, 25000,                              \
 840           "(Deprecated) Decay time (in milliseconds) to re-enable bulk "    \
 841           "rebiasing of a type after previous bulk rebias")                 \
 842           range(500, max_intx)                                              \
 843           constraint(BiasedLockingDecayTimeFunc,AfterErgo)                  \
 844                                                                             \
 845   product(intx, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC,             \
 846              "Detect and take action upon identifying synchronization on "  \
 847              "value based classes. Modes: "                                 \
 848              "0: off; "                                                     \
 849              "1: exit with fatal error; "                                   \
 850              "2: log message to stdout. Output file can be specified with " \
 851              "   -Xlog:valuebasedclasses. If JFR is running it will "       \
 852              "   also generate JFR events.")                                \
 853              range(0, 2)                                                    \
 854                                                                             \
 855   product(bool, ExitOnOutOfMemoryError, false,                              \
 856           "JVM exits on the first occurrence of an out-of-memory error "    \
 857           "thrown from JVM")                                                \
 858                                                                             \
 859   product(bool, CrashOnOutOfMemoryError, false,                             \
 860           "JVM aborts, producing an error log and core/mini dump, on the "  \
 861           "first occurrence of an out-of-memory error thrown from JVM")     \
 862                                                                             \
 863   /* tracing */                                                             \
 864                                                                             \
 865   develop(bool, StressRewriter, false,                                      \
 866           "Stress linktime bytecode rewriting")                             \
 867                                                                             \
 868   product(ccstr, TraceJVMTI, NULL,                                          \
 869           "Trace flags for JVMTI functions and events")                     \
 870                                                                             \
 871   product(bool, StressLdcRewrite, false, DIAGNOSTIC,                        \
 872           "Force ldc -> ldc_w rewrite during RedefineClasses. "             \
 873           "This option can change an EMCP method into an obsolete method "  \
 874           "and can affect tests that expect specific methods to be EMCP. "  \
 875           "This option should be used with caution.")                       \
 876                                                                             \
 877   product(bool, AllowRedefinitionToAddDeleteMethods, false,                 \
 878           "(Deprecated) Allow redefinition to add and delete private "      \
 879           "static or final methods for compatibility with old releases")    \
 880                                                                             \
 881   develop(bool, TraceBytecodes, false,                                      \
 882           "Trace bytecode execution")                                       \
 883                                                                             \
 884   develop(bool, TraceICs, false,                                            \
 885           "Trace inline cache changes")                                     \
 886                                                                             \
 887   notproduct(bool, TraceInvocationCounterOverflow, false,                   \
 888           "Trace method invocation counter overflow")                       \
 889                                                                             \
 890   develop(bool, TraceInlineCacheClearing, false,                            \
 891           "Trace clearing of inline caches in nmethods")                    \
 892                                                                             \
 893   develop(bool, TraceDependencies, false,                                   \
 894           "Trace dependencies")                                             \
 895                                                                             \
 896   develop(bool, VerifyDependencies, trueInDebug,                            \
 897           "Exercise and verify the compilation dependency mechanism")       \
 898                                                                             \
 899   develop(bool, TraceNewOopMapGeneration, false,                            \
 900           "Trace OopMapGeneration")                                         \
 901                                                                             \
 902   develop(bool, TraceNewOopMapGenerationDetailed, false,                    \
 903           "Trace OopMapGeneration: print detailed cell states")             \
 904                                                                             \
 905   develop(bool, TimeOopMap, false,                                          \
 906           "Time calls to GenerateOopMap::compute_map() in sum")             \
 907                                                                             \
 908   develop(bool, TimeOopMap2, false,                                         \
 909           "Time calls to GenerateOopMap::compute_map() individually")       \
 910                                                                             \
 911   develop(bool, TraceOopMapRewrites, false,                                 \
 912           "Trace rewriting of methods during oop map generation")           \
 913                                                                             \
 914   develop(bool, TraceICBuffer, false,                                       \
 915           "Trace usage of IC buffer")                                       \
 916                                                                             \
 917   develop(bool, TraceCompiledIC, false,                                     \
 918           "Trace changes of compiled IC")                                   \
 919                                                                             \
 920   develop(bool, FLSVerifyDictionary, false,                                 \
 921           "Do lots of (expensive) FLS dictionary verification")             \
 922                                                                             \
 923   product(uintx, ProcessDistributionStride, 4,                              \
 924           "Stride through processors when distributing processes")          \
 925           range(0, max_juint)                                               \
 926                                                                             \
 927   develop(bool, TraceFinalizerRegistration, false,                          \
 928           "Trace registration of final references")                         \
 929                                                                             \
 930   product(bool, IgnoreEmptyClassPaths, false,                               \
 931           "Ignore empty path elements in -classpath")                       \
 932                                                                             \
 933   product(bool, PrintHeapAtSIGBREAK, true,                                  \
 934           "Print heap layout in response to SIGBREAK")                      \
 935                                                                             \
 936   product(bool, PrintClassHistogram, false, MANAGEABLE,                     \
 937           "Print a histogram of class instances")                           \
 938                                                                             \
 939   product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL,              \
 940           "The percentage of the used heap that the instances of a class "  \
 941           "must occupy for the class to generate a trace event")            \
 942           range(0.0, 100.0)                                                 \
 943                                                                             \
 944   /* JVMTI heap profiling */                                                \
 945                                                                             \
 946   product(bool, VerifyBeforeIteration, false, DIAGNOSTIC,                   \
 947           "Verify memory system before JVMTI iteration")                    \
 948                                                                             \
 949   /* compiler */                                                            \
 950                                                                             \
 951   /* notice: the max range value here is max_jint, not max_intx  */         \
 952   /* because of overflow issue                                   */         \
 953   product(intx, CICompilerCount, CI_COMPILER_COUNT,                         \
 954           "Number of compiler threads to run")                              \
 955           range(0, max_jint)                                                \
 956           constraint(CICompilerCountConstraintFunc, AfterErgo)              \
 957                                                                             \
 958   product(bool, UseDynamicNumberOfCompilerThreads, true,                    \
 959           "Dynamically choose the number of parallel compiler threads")     \
 960                                                                             \
 961   product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC,            \
 962              "Reduce the number of parallel compiler threads when they "    \
 963              "are not used")                                                \
 964                                                                             \
 965   product(bool, TraceCompilerThreads, false, DIAGNOSTIC,                    \
 966              "Trace creation and removal of compiler threads")              \
 967                                                                             \
 968   develop(bool, InjectCompilerCreationFailure, false,                       \
 969           "Inject thread creation failures for "                            \
 970           "UseDynamicNumberOfCompilerThreads")                              \
 971                                                                             \
 972   develop(bool, GenerateSynchronizationCode, true,                          \
 973           "generate locking/unlocking code for synchronized methods and "   \
 974           "monitors")                                                       \
 975                                                                             \
 976   develop(bool, GenerateRangeChecks, true,                                  \
 977           "Generate range checks for array accesses")                       \
 978                                                                             \
 979   product_pd(bool, ImplicitNullChecks, DIAGNOSTIC,                          \
 980           "Generate code for implicit null checks")                         \
 981                                                                             \
 982   product_pd(bool, TrapBasedNullChecks,                                     \
 983           "Generate code for null checks that uses a cmp and trap "         \
 984           "instruction raising SIGTRAP.  This is only used if an access to" \
 985           "null (+offset) will not raise a SIGSEGV, i.e.,"                  \
 986           "ImplicitNullChecks don't work (PPC64).")                         \
 987                                                                             \
 988   product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC,         \
 989              "Enable Thread SMR Statistics")                                \
 990                                                                             \
 991   product(bool, UseNotificationThread, true,                                \
 992           "Use Notification Thread")                                        \
 993                                                                             \
 994   product(bool, Inline, true,                                               \
 995           "Enable inlining")                                                \
 996                                                                             \
 997   product(bool, ClipInlining, true,                                         \
 998           "Clip inlining if aggregate method exceeds DesiredMethodLimit")   \
 999                                                                             \
1000   develop(bool, UseCHA, true,                                               \
1001           "Enable CHA")                                                     \
1002                                                                             \
1003   product(bool, UseVtableBasedCHA, true,  DIAGNOSTIC,                       \
1004           "Use vtable information during CHA")                              \
1005                                                                             \
1006   product(bool, UseTypeProfile, true,                                       \
1007           "Check interpreter profile for historically monomorphic calls")   \
1008                                                                             \
1009   product(bool, PrintInlining, false, DIAGNOSTIC,                           \
1010           "Print inlining optimizations")                                   \
1011                                                                             \
1012   product(bool, UsePopCountInstruction, false,                              \
1013           "Use population count instruction")                               \
1014                                                                             \
1015   develop(bool, EagerInitialization, false,                                 \
1016           "Eagerly initialize classes if possible")                         \
1017                                                                             \
1018   product(bool, LogTouchedMethods, false, DIAGNOSTIC,                       \
1019           "Log methods which have been ever touched in runtime")            \
1020                                                                             \
1021   product(bool, PrintTouchedMethodsAtExit, false, DIAGNOSTIC,               \
1022           "Print all methods that have been ever touched in runtime")       \
1023                                                                             \
1024   develop(bool, TraceMethodReplacement, false,                              \
1025           "Print when methods are replaced do to recompilation")            \
1026                                                                             \
1027   develop(bool, PrintMethodFlushing, false,                                 \
1028           "Print the nmethods being flushed")                               \
1029                                                                             \
1030   product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC,           \
1031           "print statistics about method flushing")                         \
1032                                                                             \
1033   product(intx, HotMethodDetectionLimit, 100000, DIAGNOSTIC,                \
1034           "Number of compiled code invocations after which "                \
1035           "the method is considered as hot by the flusher")                 \
1036           range(1, max_jint)                                                \
1037                                                                             \
1038   product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC,                       \
1039           "Minimum number of sweeper passes before an nmethod "             \
1040           "can be flushed")                                                 \
1041           range(0, max_intx)                                                \
1042                                                                             \
1043   product(bool, UseCodeAging, true,                                         \
1044           "Insert counter to detect warm methods")                          \
1045                                                                             \
1046   product(bool, StressCodeAging, false, DIAGNOSTIC,                         \
1047           "Start with counters compiled in")                                \
1048                                                                             \
1049   develop(bool, StressCodeBuffers, false,                                   \
1050           "Exercise code buffer expansion and other rare state changes")    \
1051                                                                             \
1052   product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC,                \
1053           "Generate extra debugging information for non-safepoints in "     \
1054           "nmethods")                                                       \
1055                                                                             \
1056   product(bool, PrintVMOptions, false,                                      \
1057           "Print flags that appeared on the command line")                  \
1058                                                                             \
1059   product(bool, IgnoreUnrecognizedVMOptions, false,                         \
1060           "Ignore unrecognized VM options")                                 \
1061                                                                             \
1062   product(bool, PrintCommandLineFlags, false,                               \
1063           "Print flags specified on command line or set by ergonomics")     \
1064                                                                             \
1065   product(bool, PrintFlagsInitial, false,                                   \
1066           "Print all VM flags before argument processing and exit VM")      \
1067                                                                             \
1068   product(bool, PrintFlagsFinal, false,                                     \
1069           "Print all VM flags after argument and ergonomic processing")     \
1070                                                                             \
1071   notproduct(bool, PrintFlagsWithComments, false,                           \
1072           "Print all VM flags with default values and descriptions and "    \
1073           "exit")                                                           \
1074                                                                             \
1075   product(bool, PrintFlagsRanges, false,                                    \
1076           "Print VM flags and their ranges")                                \
1077                                                                             \
1078   product(bool, SerializeVMOutput, true, DIAGNOSTIC,                        \
1079           "Use a mutex to serialize output to tty and LogFile")             \
1080                                                                             \
1081   product(bool, DisplayVMOutput, true, DIAGNOSTIC,                          \
1082           "Display all VM output on the tty, independently of LogVMOutput") \
1083                                                                             \
1084   product(bool, LogVMOutput, false, DIAGNOSTIC,                             \
1085           "Save VM output to LogFile")                                      \
1086                                                                             \
1087   product(ccstr, LogFile, NULL, DIAGNOSTIC,                                 \
1088           "If LogVMOutput or LogCompilation is on, save VM output to "      \
1089           "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1090                                                                             \
1091   product(ccstr, ErrorFile, NULL,                                           \
1092           "If an error occurs, save the error data to this file "           \
1093           "[default: ./hs_err_pid%p.log] (%p replaced with pid)")           \
1094                                                                             \
1095   product(bool, ExtensiveErrorReports,                                      \
1096           PRODUCT_ONLY(false) NOT_PRODUCT(true),                            \
1097           "Error reports are more extensive.")                              \
1098                                                                             \
1099   product(bool, DisplayVMOutputToStderr, false,                             \
1100           "If DisplayVMOutput is true, display all VM output to stderr")    \
1101                                                                             \
1102   product(bool, DisplayVMOutputToStdout, false,                             \
1103           "If DisplayVMOutput is true, display all VM output to stdout")    \
1104                                                                             \
1105   product(bool, ErrorFileToStderr, false,                                   \
1106           "If true, error data is printed to stderr instead of a file")     \
1107                                                                             \
1108   product(bool, ErrorFileToStdout, false,                                   \
1109           "If true, error data is printed to stdout instead of a file")     \
1110                                                                             \
1111   product(bool, UseHeavyMonitors, false,                                    \
1112           "use heavyweight instead of lightweight Java monitors")           \
1113                                                                             \
1114   product(bool, PrintStringTableStatistics, false,                          \
1115           "print statistics about the StringTable and SymbolTable")         \
1116                                                                             \
1117   product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC,                 \
1118           "verify StringTable contents at exit")                            \
1119                                                                             \
1120   notproduct(bool, PrintSymbolTableSizeHistogram, false,                    \
1121           "print histogram of the symbol table")                            \
1122                                                                             \
1123   product(ccstr, AbortVMOnException, NULL, DIAGNOSTIC,                      \
1124           "Call fatal if this exception is thrown.  Example: "              \
1125           "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1126                                                                             \
1127   product(ccstr, AbortVMOnExceptionMessage, NULL, DIAGNOSTIC,               \
1128           "Call fatal if the exception pointed by AbortVMOnException "      \
1129           "has this message")                                               \
1130                                                                             \
1131   develop(bool, DebugVtables, false,                                        \
1132           "add debugging code to vtable dispatch")                          \
1133                                                                             \
1134   notproduct(bool, PrintVtableStats, false,                                 \
1135           "print vtables stats at end of run")                              \
1136                                                                             \
1137   develop(bool, TraceCreateZombies, false,                                  \
1138           "trace creation of zombie nmethods")                              \
1139                                                                             \
1140   product(bool, RangeCheckElimination, true,                                \
1141           "Eliminate range checks")                                         \
1142                                                                             \
1143   develop_pd(bool, UncommonNullCast,                                        \
1144           "track occurrences of null in casts; adjust compiler tactics")    \
1145                                                                             \
1146   develop(bool, TypeProfileCasts,  true,                                    \
1147           "treat casts like calls for purposes of type profiling")          \
1148                                                                             \
1149   develop(bool, TraceLivenessGen, false,                                    \
1150           "Trace the generation of liveness analysis information")          \
1151                                                                             \
1152   notproduct(bool, TraceLivenessQuery, false,                               \
1153           "Trace queries of liveness analysis information")                 \
1154                                                                             \
1155   notproduct(bool, CollectIndexSetStatistics, false,                        \
1156           "Collect information about IndexSets")                            \
1157                                                                             \
1158   develop(intx, FastAllocateSizeLimit, 128*K,                               \
1159           /* Note:  This value is zero mod 1<<13 for a cheap sparc set. */  \
1160           "Inline allocations larger than this in doublewords must go slow")\
1161                                                                             \
1162   product_pd(bool, CompactStrings,                                          \
1163           "Enable Strings to use single byte chars in backing store")       \
1164                                                                             \
1165   product_pd(uintx, TypeProfileLevel,                                       \
1166           "=XYZ, with Z: Type profiling of arguments at call; "             \
1167                      "Y: Type profiling of return value at call; "          \
1168                      "X: Type profiling of parameters to methods; "         \
1169           "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods")             \
1170           constraint(TypeProfileLevelConstraintFunc, AfterErgo)             \
1171                                                                             \
1172   product(intx, TypeProfileArgsLimit,     2,                                \
1173           "max number of call arguments to consider for type profiling")    \
1174           range(0, 16)                                                      \
1175                                                                             \
1176   product(intx, TypeProfileParmsLimit,    2,                                \
1177           "max number of incoming parameters to consider for type profiling"\
1178           ", -1 for all")                                                   \
1179           range(-1, 64)                                                     \
1180                                                                             \
1181   /* statistics */                                                          \
1182   develop(bool, CountCompiledCalls, false,                                  \
1183           "Count method invocations")                                       \
1184                                                                             \
1185   notproduct(bool, ICMissHistogram, false,                                  \
1186           "Produce histogram of IC misses")                                 \
1187                                                                             \
1188   /* interpreter */                                                         \
1189   product_pd(bool, RewriteBytecodes,                                        \
1190           "Allow rewriting of bytecodes (bytecodes are not immutable)")     \
1191                                                                             \
1192   product_pd(bool, RewriteFrequentPairs,                                    \
1193           "Rewrite frequently used bytecode pairs into a single bytecode")  \
1194                                                                             \
1195   product(bool, PrintInterpreter, false, DIAGNOSTIC,                        \
1196           "Print the generated interpreter code")                           \
1197                                                                             \
1198   product(bool, UseInterpreter, true,                                       \
1199           "Use interpreter for non-compiled methods")                       \
1200                                                                             \
1201   develop(bool, UseFastSignatureHandlers, true,                             \
1202           "Use fast signature handlers for native calls")                   \
1203                                                                             \
1204   product(bool, UseLoopCounter, true,                                       \
1205           "Increment invocation counter on backward branch")                \
1206                                                                             \
1207   product_pd(bool, UseOnStackReplacement,                                   \
1208           "Use on stack replacement, calls runtime if invoc. counter "      \
1209           "overflows in loop")                                              \
1210                                                                             \
1211   notproduct(bool, TraceOnStackReplacement, false,                          \
1212           "Trace on stack replacement")                                     \
1213                                                                             \
1214   product_pd(bool, PreferInterpreterNativeStubs,                            \
1215           "Use always interpreter stubs for native methods invoked via "    \
1216           "interpreter")                                                    \
1217                                                                             \
1218   develop(bool, CountBytecodes, false,                                      \
1219           "Count number of bytecodes executed")                             \
1220                                                                             \
1221   develop(bool, PrintBytecodeHistogram, false,                              \
1222           "Print histogram of the executed bytecodes")                      \
1223                                                                             \
1224   develop(bool, PrintBytecodePairHistogram, false,                          \
1225           "Print histogram of the executed bytecode pairs")                 \
1226                                                                             \
1227   product(bool, PrintSignatureHandlers, false, DIAGNOSTIC,                  \
1228           "Print code generated for native method signature handlers")      \
1229                                                                             \
1230   develop(bool, VerifyOops, false,                                          \
1231           "Do plausibility checks for oops")                                \
1232                                                                             \
1233   develop(bool, CheckUnhandledOops, false,                                  \
1234           "Check for unhandled oops in VM code")                            \
1235                                                                             \
1236   develop(bool, VerifyJNIFields, trueInDebug,                               \
1237           "Verify jfieldIDs for instance fields")                           \
1238                                                                             \
1239   notproduct(bool, VerifyJNIEnvThread, false,                               \
1240           "Verify JNIEnv.thread == Thread::current() when entering VM "     \
1241           "from JNI")                                                       \
1242                                                                             \
1243   develop(bool, VerifyFPU, false,                                           \
1244           "Verify FPU state (check for NaN's, etc.)")                       \
1245                                                                             \
1246   develop(bool, VerifyThread, false,                                        \
1247           "Watch the thread register for corruption (SPARC only)")          \
1248                                                                             \
1249   develop(bool, VerifyActivationFrameSize, false,                           \
1250           "Verify that activation frame didn't become smaller than its "    \
1251           "minimal size")                                                   \
1252                                                                             \
1253   develop(bool, TraceFrequencyInlining, false,                              \
1254           "Trace frequency based inlining")                                 \
1255                                                                             \
1256   develop_pd(bool, InlineIntrinsics,                                        \
1257           "Inline intrinsics that can be statically resolved")              \
1258                                                                             \
1259   product_pd(bool, ProfileInterpreter,                                      \
1260           "Profile at the bytecode level during interpretation")            \
1261                                                                             \
1262   develop_pd(bool, ProfileTraps,                                            \
1263           "Profile deoptimization traps at the bytecode level")             \
1264                                                                             \
1265   product(intx, ProfileMaturityPercentage, 20,                              \
1266           "number of method invocations/branches (expressed as % of "       \
1267           "CompileThreshold) before using the method's profile")            \
1268           range(0, 100)                                                     \
1269                                                                             \
1270   product(bool, PrintMethodData, false, DIAGNOSTIC,                         \
1271           "Print the results of +ProfileInterpreter at end of run")         \
1272                                                                             \
1273   develop(bool, VerifyDataPointer, trueInDebug,                             \
1274           "Verify the method data pointer during interpreter profiling")    \
1275                                                                             \
1276   notproduct(bool, CrashGCForDumpingJavaThread, false,                      \
1277           "Manually make GC thread crash then dump java stack trace;  "     \
1278           "Test only")                                                      \
1279                                                                             \
1280   /* compilation */                                                         \
1281   product(bool, UseCompiler, true,                                          \
1282           "Use Just-In-Time compilation")                                   \
1283                                                                             \
1284   product(bool, UseCounterDecay, true,                                      \
1285           "Adjust recompilation counters")                                  \
1286                                                                             \
1287   develop(intx, CounterHalfLifeTime,    30,                                 \
1288           "Half-life time of invocation counters (in seconds)")             \
1289                                                                             \
1290   develop(intx, CounterDecayMinIntervalLength,   500,                       \
1291           "The minimum interval (in milliseconds) between invocation of "   \
1292           "CounterDecay")                                                   \
1293                                                                             \
1294   product(bool, AlwaysCompileLoopMethods, false,                            \
1295           "When using recompilation, never interpret methods "              \
1296           "containing loops")                                               \
1297                                                                             \
1298   product(intx,  AllocatePrefetchStyle, 1,                                  \
1299           "0 = no prefetch, "                                               \
1300           "1 = generate prefetch instructions for each allocation, "        \
1301           "2 = use TLAB watermark to gate allocation prefetch, "            \
1302           "3 = generate one prefetch instruction per cache line")           \
1303           range(0, 3)                                                       \
1304                                                                             \
1305   product(intx,  AllocatePrefetchDistance, -1,                              \
1306           "Distance to prefetch ahead of allocation pointer. "              \
1307           "-1: use system-specific value (automatically determined")        \
1308           constraint(AllocatePrefetchDistanceConstraintFunc,AfterMemoryInit)\
1309                                                                             \
1310   product(intx,  AllocatePrefetchLines, 3,                                  \
1311           "Number of lines to prefetch ahead of array allocation pointer")  \
1312           range(1, 64)                                                      \
1313                                                                             \
1314   product(intx,  AllocateInstancePrefetchLines, 1,                          \
1315           "Number of lines to prefetch ahead of instance allocation "       \
1316           "pointer")                                                        \
1317           range(1, 64)                                                      \
1318                                                                             \
1319   product(intx,  AllocatePrefetchStepSize, 16,                              \
1320           "Step size in bytes of sequential prefetch instructions")         \
1321           range(1, 512)                                                     \
1322           constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1323                                                                             \
1324   product(intx,  AllocatePrefetchInstr, 0,                                  \
1325           "Select instruction to prefetch ahead of allocation pointer")     \
1326           constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit)  \
1327                                                                             \
1328   /* deoptimization */                                                      \
1329   develop(bool, TraceDeoptimization, false,                                 \
1330           "Trace deoptimization")                                           \
1331                                                                             \
1332   develop(bool, PrintDeoptimizationDetails, false,                          \
1333           "Print more information about deoptimization")                    \
1334                                                                             \
1335   develop(bool, DebugDeoptimization, false,                                 \
1336           "Tracing various information while debugging deoptimization")     \
1337                                                                             \
1338   product(intx, SelfDestructTimer, 0,                                       \
1339           "Will cause VM to terminate after a given time (in minutes) "     \
1340           "(0 means off)")                                                  \
1341           range(0, max_intx)                                                \
1342                                                                             \
1343   product(intx, MaxJavaStackTraceDepth, 1024,                               \
1344           "The maximum number of lines in the stack trace for Java "        \
1345           "exceptions (0 means all)")                                       \
1346           range(0, max_jint/2)                                              \
1347                                                                             \
1348   /* notice: the max range value here is max_jint, not max_intx  */         \
1349   /* because of overflow issue                                   */         \
1350   product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC,              \
1351           "Guarantee a safepoint (at least) every so many milliseconds "    \
1352           "(0 means none)")                                                 \
1353           range(0, max_jint)                                                \
1354                                                                             \
1355   product(intx, SafepointTimeoutDelay, 10000,                               \
1356           "Delay in milliseconds for option SafepointTimeout")              \
1357           range(0, max_intx LP64_ONLY(/MICROUNITS))                         \
1358                                                                             \
1359   product(intx, NmethodSweepActivity, 10,                                   \
1360           "Removes cold nmethods from code cache if > 0. Higher values "    \
1361           "result in more aggressive sweeping")                             \
1362           range(0, 2000)                                                    \
1363                                                                             \
1364   notproduct(bool, LogSweeper, false,                                       \
1365           "Keep a ring buffer of sweeper activity")                         \
1366                                                                             \
1367   notproduct(intx, SweeperLogEntries, 1024,                                 \
1368           "Number of records in the ring buffer of sweeper activity")       \
1369                                                                             \
1370   develop(intx, MallocCatchPtr, -1,                                         \
1371           "Hit breakpoint when mallocing/freeing this pointer")             \
1372                                                                             \
1373   notproduct(ccstrlist, SuppressErrorAt, "",                                \
1374           "List of assertions (file:line) to muzzle")                       \
1375                                                                             \
1376   develop(intx, StackPrintLimit, 100,                                       \
1377           "number of stack frames to print in VM-level stack dump")         \
1378                                                                             \
1379   product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC,                       \
1380           "max number of compiled code units to print in error log")        \
1381           range(0, VMError::max_error_log_print_code)                       \
1382                                                                             \
1383   notproduct(intx, MaxElementPrintSize, 256,                                \
1384           "maximum number of elements to print")                            \
1385                                                                             \
1386   notproduct(intx, MaxSubklassPrintSize, 4,                                 \
1387           "maximum number of subklasses to print when printing klass")      \
1388                                                                             \
1389   develop(intx, MaxForceInlineLevel, 100,                                   \
1390           "maximum number of nested calls that are forced for inlining "    \
1391           "(using CompileCommand or marked w/ @ForceInline)")               \
1392           range(0, max_jint)                                                \
1393                                                                             \
1394   product(intx, MinInliningThreshold, 250,                                  \
1395           "The minimum invocation count a method needs to have to be "      \
1396           "inlined")                                                        \
1397           range(0, max_jint)                                                \
1398                                                                             \
1399   develop(intx, MethodHistogramCutoff, 100,                                 \
1400           "The cutoff value for method invocation histogram (+CountCalls)") \
1401                                                                             \
1402   develop(intx, DontYieldALotInterval,    10,                               \
1403           "Interval between which yields will be dropped (milliseconds)")   \
1404                                                                             \
1405   notproduct(intx, DeoptimizeALotInterval,     5,                           \
1406           "Number of exits until DeoptimizeALot kicks in")                  \
1407                                                                             \
1408   notproduct(intx, ZombieALotInterval,     5,                               \
1409           "Number of exits until ZombieALot kicks in")                      \
1410                                                                             \
1411   product(uintx, MallocMaxTestWords,     0, DIAGNOSTIC,                     \
1412           "If non-zero, maximum number of words that malloc/realloc can "   \
1413           "allocate (for testing only)")                                    \
1414           range(0, max_uintx)                                               \
1415                                                                             \
1416   product(intx, TypeProfileWidth, 2,                                        \
1417           "Number of receiver types to record in call/cast profile")        \
1418           range(0, 8)                                                       \
1419                                                                             \
1420   develop(intx, BciProfileWidth,      2,                                    \
1421           "Number of return bci's to record in ret profile")                \
1422                                                                             \
1423   product(intx, PerMethodRecompilationCutoff, 400,                          \
1424           "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1425           range(-1, max_intx)                                               \
1426                                                                             \
1427   product(intx, PerBytecodeRecompilationCutoff, 200,                        \
1428           "Per-BCI limit on repeated recompilation (-1=>'Inf')")            \
1429           range(-1, max_intx)                                               \
1430                                                                             \
1431   product(intx, PerMethodTrapLimit,  100,                                   \
1432           "Limit on traps (of one kind) in a method (includes inlines)")    \
1433           range(0, max_jint)                                                \
1434                                                                             \
1435   product(intx, PerMethodSpecTrapLimit,  5000, EXPERIMENTAL,                \
1436           "Limit on speculative traps (of one kind) in a method "           \
1437           "(includes inlines)")                                             \
1438           range(0, max_jint)                                                \
1439                                                                             \
1440   product(intx, PerBytecodeTrapLimit,  4,                                   \
1441           "Limit on traps (of one kind) at a particular BCI")               \
1442           range(0, max_jint)                                                \
1443                                                                             \
1444   product(intx, SpecTrapLimitExtraEntries,  3, EXPERIMENTAL,                \
1445           "Extra method data trap entries for speculation")                 \
1446                                                                             \
1447   develop(intx, InlineFrequencyRatio,    20,                                \
1448           "Ratio of call site execution to caller method invocation")       \
1449           range(0, max_jint)                                                \
1450                                                                             \
1451   product_pd(intx, InlineFrequencyCount, DIAGNOSTIC,                        \
1452           "Count of call site execution necessary to trigger frequent "     \
1453           "inlining")                                                       \
1454           range(0, max_jint)                                                \
1455                                                                             \
1456   develop(intx, InlineThrowCount,    50,                                    \
1457           "Force inlining of interpreted methods that throw this often")    \
1458           range(0, max_jint)                                                \
1459                                                                             \
1460   develop(intx, InlineThrowMaxSize,   200,                                  \
1461           "Force inlining of throwing methods smaller than this")           \
1462           range(0, max_jint)                                                \
1463                                                                             \
1464   product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M),        \
1465           "Initial threshold (in bytes) at which a garbage collection "     \
1466           "is done to reduce Metaspace usage")                              \
1467           constraint(MetaspaceSizeConstraintFunc,AfterErgo)                 \
1468                                                                             \
1469   product(size_t, MaxMetaspaceSize, max_uintx,                              \
1470           "Maximum size of Metaspaces (in bytes)")                          \
1471           constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo)              \
1472                                                                             \
1473   product(size_t, CompressedClassSpaceSize, 1*G,                            \
1474           "Maximum size of class area in Metaspace when compressed "        \
1475           "class pointers are used")                                        \
1476           range(1*M, 3*G)                                                   \
1477                                                                             \
1478   develop(size_t, CompressedClassSpaceBaseAddress, 0,                       \
1479           "Force the class space to be allocated at this address or "       \
1480           "fails VM initialization (requires -Xshare=off.")                 \
1481                                                                             \
1482   product(ccstr, MetaspaceReclaimPolicy, "balanced",                        \
1483           "options: balanced, aggressive, none")                            \
1484                                                                             \
1485   product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC,          \
1486           "Print metaspace statistics upon VM exit.")                       \
1487                                                                             \
1488   product(bool, MetaspaceGuardAllocations, false, DIAGNOSTIC,               \
1489           "Metapace allocations are guarded.")                              \
1490                                                                             \
1491   product(bool, MetaspaceHandleDeallocations, true, DIAGNOSTIC,             \
1492           "Switch off Metapace deallocation handling.")                     \
1493                                                                             \
1494   product(uintx, MinHeapFreeRatio, 40, MANAGEABLE,                          \
1495           "The minimum percentage of heap free after GC to avoid expansion."\
1496           " For most GCs this applies to the old generation. In G1 and"     \
1497           " ParallelGC it applies to the whole heap.")                      \
1498           range(0, 100)                                                     \
1499           constraint(MinHeapFreeRatioConstraintFunc,AfterErgo)              \
1500                                                                             \
1501   product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE,                          \
1502           "The maximum percentage of heap free after GC to avoid shrinking."\
1503           " For most GCs this applies to the old generation. In G1 and"     \
1504           " ParallelGC it applies to the whole heap.")                      \
1505           range(0, 100)                                                     \
1506           constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo)              \
1507                                                                             \
1508   product(bool, ShrinkHeapInSteps, true,                                    \
1509           "When disabled, informs the GC to shrink the java heap directly"  \
1510           " to the target size at the next full GC rather than requiring"   \
1511           " smaller steps during multiple full GCs.")                       \
1512                                                                             \
1513   product(intx, SoftRefLRUPolicyMSPerMB, 1000,                              \
1514           "Number of milliseconds per MB of free space in the heap")        \
1515           range(0, max_intx)                                                \
1516           constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1517                                                                             \
1518   product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K),               \
1519           "The minimum change in heap space due to GC (in bytes)")          \
1520           range(0, max_uintx)                                               \
1521                                                                             \
1522   product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K),           \
1523           "The minimum expansion of Metaspace (in bytes)")                  \
1524           range(0, max_uintx)                                               \
1525                                                                             \
1526   product(uintx, MaxMetaspaceFreeRatio,    70,                              \
1527           "The maximum percentage of Metaspace free after GC to avoid "     \
1528           "shrinking")                                                      \
1529           range(0, 100)                                                     \
1530           constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo)         \
1531                                                                             \
1532   product(uintx, MinMetaspaceFreeRatio,    40,                              \
1533           "The minimum percentage of Metaspace free after GC to avoid "     \
1534           "expansion")                                                      \
1535           range(0, 99)                                                      \
1536           constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo)         \
1537                                                                             \
1538   product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M),             \
1539           "The maximum expansion of Metaspace without full GC (in bytes)")  \
1540           range(0, max_uintx)                                               \
1541                                                                             \
1542   /* stack parameters */                                                    \
1543   product_pd(intx, StackYellowPages,                                        \
1544           "Number of yellow zone (recoverable overflows) pages of size "    \
1545           "4KB. If pages are bigger yellow zone is aligned up.")            \
1546           range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5))     \
1547                                                                             \
1548   product_pd(intx, StackRedPages,                                           \
1549           "Number of red zone (unrecoverable overflows) pages of size "     \
1550           "4KB. If pages are bigger red zone is aligned up.")               \
1551           range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2))           \
1552                                                                             \
1553   product_pd(intx, StackReservedPages,                                      \
1554           "Number of reserved zone (reserved to annotated methods) pages"   \
1555           " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1556           range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1557                                                                             \
1558   product(bool, RestrictReservedStack, true,                                \
1559           "Restrict @ReservedStackAccess to trusted classes")               \
1560                                                                             \
1561   /* greater stack shadow pages can't generate instruction to bang stack */ \
1562   product_pd(intx, StackShadowPages,                                        \
1563           "Number of shadow zone (for overflow checking) pages of size "    \
1564           "4KB. If pages are bigger shadow zone is aligned up. "            \
1565           "This should exceed the depth of the VM and native call stack.")  \
1566           range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30))    \
1567                                                                             \
1568   product_pd(intx, ThreadStackSize,                                         \
1569           "Thread Stack Size (in Kbytes)")                                  \
1570           range(0, 1 * M)                                                   \
1571                                                                             \
1572   product_pd(intx, VMThreadStackSize,                                       \
1573           "Non-Java Thread Stack Size (in Kbytes)")                         \
1574           range(0, max_intx/(1 * K))                                        \
1575                                                                             \
1576   product_pd(intx, CompilerThreadStackSize,                                 \
1577           "Compiler Thread Stack Size (in Kbytes)")                         \
1578           range(0, max_intx/(1 * K))                                        \
1579                                                                             \
1580   develop_pd(size_t, JVMInvokeMethodSlack,                                  \
1581           "Stack space (bytes) required for JVM_InvokeMethod to complete")  \
1582                                                                             \
1583   /* code cache parameters                                    */            \
1584   product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL,                     \
1585           "Code cache segment size (in bytes) - smallest unit of "          \
1586           "allocation")                                                     \
1587           range(1, 1024)                                                    \
1588           constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo)         \
1589                                                                             \
1590   develop_pd(intx, CodeEntryAlignment,                                      \
1591           "Code entry alignment for generated code (in bytes)")             \
1592           constraint(CodeEntryAlignmentConstraintFunc, AfterErgo)           \
1593                                                                             \
1594   product_pd(intx, OptoLoopAlignment,                                       \
1595           "Align inner loops to zero relative to this modulus")             \
1596           range(1, 16)                                                      \
1597           constraint(OptoLoopAlignmentConstraintFunc, AfterErgo)            \
1598                                                                             \
1599   product_pd(uintx, InitialCodeCacheSize,                                   \
1600           "Initial code cache size (in bytes)")                             \
1601           constraint(VMPageSizeConstraintFunc, AtParse)                     \
1602                                                                             \
1603   develop_pd(uintx, CodeCacheMinimumUseSpace,                               \
1604           "Minimum code cache size (in bytes) required to start VM.")       \
1605           range(0, max_uintx)                                               \
1606                                                                             \
1607   product(bool, SegmentedCodeCache, false,                                  \
1608           "Use a segmented code cache")                                     \
1609                                                                             \
1610   product_pd(uintx, ReservedCodeCacheSize,                                  \
1611           "Reserved code cache size (in bytes) - maximum code cache size")  \
1612           constraint(VMPageSizeConstraintFunc, AtParse)                     \
1613                                                                             \
1614   product_pd(uintx, NonProfiledCodeHeapSize,                                \
1615           "Size of code heap with non-profiled methods (in bytes)")         \
1616           range(0, max_uintx)                                               \
1617                                                                             \
1618   product_pd(uintx, ProfiledCodeHeapSize,                                   \
1619           "Size of code heap with profiled methods (in bytes)")             \
1620           range(0, max_uintx)                                               \
1621                                                                             \
1622   product_pd(uintx, NonNMethodCodeHeapSize,                                 \
1623           "Size of code heap with non-nmethods (in bytes)")                 \
1624           constraint(VMPageSizeConstraintFunc, AtParse)                     \
1625                                                                             \
1626   product_pd(uintx, CodeCacheExpansionSize,                                 \
1627           "Code cache expansion size (in bytes)")                           \
1628           range(32*K, max_uintx)                                            \
1629                                                                             \
1630   product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC,                    \
1631           "Minimum number of segments in a code cache block")               \
1632           range(1, 100)                                                     \
1633                                                                             \
1634   notproduct(bool, ExitOnFullCodeCache, false,                              \
1635           "Exit the VM if we fill the code cache")                          \
1636                                                                             \
1637   product(bool, UseCodeCacheFlushing, true,                                 \
1638           "Remove cold/old nmethods from the code cache")                   \
1639                                                                             \
1640   product(double, SweeperThreshold, 0.5,                                    \
1641           "Threshold controlling when code cache sweeper is invoked."       \
1642           "Value is percentage of ReservedCodeCacheSize.")                  \
1643           range(0.0, 100.0)                                                 \
1644                                                                             \
1645   product(uintx, StartAggressiveSweepingAt, 10,                             \
1646           "Start aggressive sweeping if X[%] of the code cache is free."    \
1647           "Segmented code cache: X[%] of the non-profiled heap."            \
1648           "Non-segmented code cache: X[%] of the total code cache")         \
1649           range(0, 100)                                                     \
1650                                                                             \
1651   /* interpreter debugging */                                               \
1652   develop(intx, BinarySwitchThreshold, 5,                                   \
1653           "Minimal number of lookupswitch entries for rewriting to binary " \
1654           "switch")                                                         \
1655                                                                             \
1656   develop(intx, StopInterpreterAt, 0,                                       \
1657           "Stop interpreter execution at specified bytecode number")        \
1658                                                                             \
1659   develop(intx, TraceBytecodesAt, 0,                                        \
1660           "Trace bytecodes starting with specified bytecode number")        \
1661                                                                             \
1662   /* Priorities */                                                          \
1663   product_pd(bool, UseThreadPriorities,  "Use native thread priorities")    \
1664                                                                             \
1665   product(intx, ThreadPriorityPolicy, 0,                                    \
1666           "0 : Normal.                                                     "\
1667           "    VM chooses priorities that are appropriate for normal       "\
1668           "    applications.                                               "\
1669           "    On Windows applications are allowed to use higher native    "\
1670           "    priorities. However, with ThreadPriorityPolicy=0, VM will   "\
1671           "    not use the highest possible native priority,               "\
1672           "    THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with     "\
1673           "    system threads. On Linux thread priorities are ignored      "\
1674           "    because the OS does not support static priority in          "\
1675           "    SCHED_OTHER scheduling class which is the only choice for   "\
1676           "    non-root, non-realtime applications.                        "\
1677           "1 : Aggressive.                                                 "\
1678           "    Java thread priorities map over to the entire range of      "\
1679           "    native thread priorities. Higher Java thread priorities map "\
1680           "    to higher native thread priorities. This policy should be   "\
1681           "    used with care, as sometimes it can cause performance       "\
1682           "    degradation in the application and/or the entire system. On "\
1683           "    Linux/BSD/macOS this policy requires root privilege or an   "\
1684           "    extended capability.")                                       \
1685           range(0, 1)                                                       \
1686                                                                             \
1687   product(bool, ThreadPriorityVerbose, false,                               \
1688           "Print priority changes")                                         \
1689                                                                             \
1690   product(intx, CompilerThreadPriority, -1,                                 \
1691           "The native priority at which compiler threads should run "       \
1692           "(-1 means no change)")                                           \
1693           range(min_jint, max_jint)                                         \
1694                                                                             \
1695   product(intx, VMThreadPriority, -1,                                       \
1696           "The native priority at which the VM thread should run "          \
1697           "(-1 means no change)")                                           \
1698           range(-1, 127)                                                    \
1699                                                                             \
1700   product(intx, JavaPriority1_To_OSPriority, -1,                            \
1701           "Map Java priorities to OS priorities")                           \
1702           range(-1, 127)                                                    \
1703                                                                             \
1704   product(intx, JavaPriority2_To_OSPriority, -1,                            \
1705           "Map Java priorities to OS priorities")                           \
1706           range(-1, 127)                                                    \
1707                                                                             \
1708   product(intx, JavaPriority3_To_OSPriority, -1,                            \
1709           "Map Java priorities to OS priorities")                           \
1710           range(-1, 127)                                                    \
1711                                                                             \
1712   product(intx, JavaPriority4_To_OSPriority, -1,                            \
1713           "Map Java priorities to OS priorities")                           \
1714           range(-1, 127)                                                    \
1715                                                                             \
1716   product(intx, JavaPriority5_To_OSPriority, -1,                            \
1717           "Map Java priorities to OS priorities")                           \
1718           range(-1, 127)                                                    \
1719                                                                             \
1720   product(intx, JavaPriority6_To_OSPriority, -1,                            \
1721           "Map Java priorities to OS priorities")                           \
1722           range(-1, 127)                                                    \
1723                                                                             \
1724   product(intx, JavaPriority7_To_OSPriority, -1,                            \
1725           "Map Java priorities to OS priorities")                           \
1726           range(-1, 127)                                                    \
1727                                                                             \
1728   product(intx, JavaPriority8_To_OSPriority, -1,                            \
1729           "Map Java priorities to OS priorities")                           \
1730           range(-1, 127)                                                    \
1731                                                                             \
1732   product(intx, JavaPriority9_To_OSPriority, -1,                            \
1733           "Map Java priorities to OS priorities")                           \
1734           range(-1, 127)                                                    \
1735                                                                             \
1736   product(intx, JavaPriority10_To_OSPriority,-1,                            \
1737           "Map Java priorities to OS priorities")                           \
1738           range(-1, 127)                                                    \
1739                                                                             \
1740   product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL,         \
1741           "Java thread priority 10 maps to critical scheduling priority")   \
1742                                                                             \
1743   product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL,     \
1744           "Compiler thread(s) run at critical scheduling priority")         \
1745                                                                             \
1746   develop(intx, NewCodeParameter,      0,                                   \
1747           "Testing Only: Create a dedicated integer parameter before "      \
1748           "putback")                                                        \
1749                                                                             \
1750   /* new oopmap storage allocation */                                       \
1751   develop(intx, MinOopMapAllocation,     8,                                 \
1752           "Minimum number of OopMap entries in an OopMapSet")               \
1753                                                                             \
1754   /* recompilation */                                                       \
1755   product_pd(intx, CompileThreshold,                                        \
1756           "number of interpreted method invocations before (re-)compiling") \
1757           constraint(CompileThresholdConstraintFunc, AfterErgo)             \
1758                                                                             \
1759   product_pd(bool, TieredCompilation,                                       \
1760           "Enable tiered compilation")                                      \
1761                                                                             \
1762   /* Properties for Java libraries  */                                      \
1763                                                                             \
1764   product(uint64_t, MaxDirectMemorySize, 0,                                 \
1765           "Maximum total size of NIO direct-buffer allocations")            \
1766           range(0, max_jlong)                                               \
1767                                                                             \
1768   /* Flags used for temporary code during development  */                   \
1769                                                                             \
1770   product(bool, UseNewCode, false, DIAGNOSTIC,                              \
1771           "Testing Only: Use the new version while testing")                \
1772                                                                             \
1773   product(bool, UseNewCode2, false, DIAGNOSTIC,                             \
1774           "Testing Only: Use the new version while testing")                \
1775                                                                             \
1776   product(bool, UseNewCode3, false, DIAGNOSTIC,                             \
1777           "Testing Only: Use the new version while testing")                \
1778                                                                             \
1779   notproduct(bool, UseDebuggerErgo, false,                                  \
1780           "Debugging Only: Adjust the VM to be more debugger-friendly. "    \
1781           "Turns on the other UseDebuggerErgo* flags")                      \
1782                                                                             \
1783   notproduct(bool, UseDebuggerErgo1, false,                                 \
1784           "Debugging Only: Enable workarounds for debugger induced "        \
1785           "os::processor_id() >= os::processor_count() problems")           \
1786                                                                             \
1787   notproduct(bool, UseDebuggerErgo2, false,                                 \
1788           "Debugging Only: Limit the number of spawned JVM threads")        \
1789                                                                             \
1790   notproduct(bool, EnableJVMTIStackDepthAsserts, true,                      \
1791           "Enable JVMTI asserts related to stack depth checks")             \
1792                                                                             \
1793   /* flags for performance data collection */                               \
1794                                                                             \
1795   product(bool, UsePerfData, true,                                          \
1796           "Flag to disable jvmstat instrumentation for performance testing "\
1797           "and problem isolation purposes")                                 \
1798                                                                             \
1799   product(bool, PerfDataSaveToFile, false,                                  \
1800           "Save PerfData memory to hsperfdata_<pid> file on exit")          \
1801                                                                             \
1802   product(ccstr, PerfDataSaveFile, NULL,                                    \
1803           "Save PerfData memory to the specified absolute pathname. "       \
1804           "The string %p in the file name (if present) "                    \
1805           "will be replaced by pid")                                        \
1806                                                                             \
1807   product(intx, PerfDataSamplingInterval, 50,                               \
1808           "Data sampling interval (in milliseconds)")                       \
1809           range(PeriodicTask::min_interval, max_jint)                       \
1810           constraint(PerfDataSamplingIntervalFunc, AfterErgo)               \
1811                                                                             \
1812   product(bool, PerfDisableSharedMem, false,                                \
1813           "Store performance data in standard memory")                      \
1814                                                                             \
1815   product(intx, PerfDataMemorySize, 32*K,                                   \
1816           "Size of performance data memory region. Will be rounded "        \
1817           "up to a multiple of the native os page size.")                   \
1818           range(128, 32*64*K)                                               \
1819                                                                             \
1820   product(intx, PerfMaxStringConstLength, 1024,                             \
1821           "Maximum PerfStringConstant string length before truncation")     \
1822           range(32, 32*K)                                                   \
1823                                                                             \
1824   product(bool, PerfAllowAtExitRegistration, false,                         \
1825           "Allow registration of atexit() methods")                         \
1826                                                                             \
1827   product(bool, PerfBypassFileSystemCheck, false,                           \
1828           "Bypass Win32 file system criteria checks (Windows Only)")        \
1829                                                                             \
1830   product(intx, UnguardOnExecutionViolation, 0,                             \
1831           "Unguard page and retry on no-execute fault (Win32 only) "        \
1832           "0=off, 1=conservative, 2=aggressive")                            \
1833           range(0, 2)                                                       \
1834                                                                             \
1835   /* Serviceability Support */                                              \
1836                                                                             \
1837   product(bool, ManagementServer, false,                                    \
1838           "Create JMX Management Server")                                   \
1839                                                                             \
1840   product(bool, DisableAttachMechanism, false,                              \
1841           "Disable mechanism that allows tools to attach to this VM")       \
1842                                                                             \
1843   product(bool, StartAttachListener, false,                                 \
1844           "Always start Attach Listener at VM startup")                     \
1845                                                                             \
1846   product(bool, EnableDynamicAgentLoading, true,                            \
1847           "Allow tools to load agents with the attach mechanism")           \
1848                                                                             \
1849   product(bool, PrintConcurrentLocks, false, MANAGEABLE,                    \
1850           "Print java.util.concurrent locks in thread dump")                \
1851                                                                             \
1852   /* Shared spaces */                                                       \
1853                                                                             \
1854   product(bool, UseSharedSpaces, true,                                      \
1855           "Use shared spaces for metadata")                                 \
1856                                                                             \
1857   product(bool, VerifySharedSpaces, false,                                  \
1858           "Verify integrity of shared spaces")                              \
1859                                                                             \
1860   product(bool, RequireSharedSpaces, false,                                 \
1861           "Require shared spaces for metadata")                             \
1862                                                                             \
1863   product(bool, DumpSharedSpaces, false,                                    \
1864           "Special mode: JVM reads a class list, loads classes, builds "    \
1865           "shared spaces, and dumps the shared spaces to a file to be "     \
1866           "used in future JVM runs")                                        \
1867                                                                             \
1868   product(bool, DynamicDumpSharedSpaces, false,                             \
1869           "Dynamic archive")                                                \
1870                                                                             \
1871   product(bool, RecordDynamicDumpInfo, false,                               \
1872           "Record class info for jcmd VM.cds dynamic_dump")                 \
1873                                                                             \
1874   product(bool, PrintSharedArchiveAndExit, false,                           \
1875           "Print shared archive file contents")                             \
1876                                                                             \
1877   product(bool, PrintSharedDictionary, false,                               \
1878           "If PrintSharedArchiveAndExit is true, also print the shared "    \
1879           "dictionary")                                                     \
1880                                                                             \
1881   product(size_t, SharedBaseAddress, LP64_ONLY(32*G)                        \
1882           NOT_LP64(LINUX_ONLY(2*G) NOT_LINUX(0)),                           \
1883           "Address to allocate shared memory region for class data")        \
1884           range(0, SIZE_MAX)                                                \
1885                                                                             \
1886   product(ccstr, SharedArchiveConfigFile, NULL,                             \
1887           "Data to add to the CDS archive file")                            \
1888                                                                             \
1889   product(uintx, SharedSymbolTableBucketSize, 4,                            \
1890           "Average number of symbols per bucket in shared table")           \
1891           range(2, 246)                                                     \
1892                                                                             \
1893   product(bool, AllowArchivingWithJavaAgent, false, DIAGNOSTIC,             \
1894           "Allow Java agent to be run with CDS dumping")                    \
1895                                                                             \
1896   product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC,                  \
1897           "Print generated stub code for method handles")                   \
1898                                                                             \
1899   product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC,               \
1900           "perform extra checks when constructing method handles")          \
1901                                                                             \
1902   product(bool, ShowHiddenFrames, false, DIAGNOSTIC,                        \
1903           "show method handle implementation frames (usually hidden)")      \
1904                                                                             \
1905   product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL,             \
1906           "trust final non-static declarations for constant folding")       \
1907                                                                             \
1908   product(bool, FoldStableValues, true, DIAGNOSTIC,                         \
1909           "Optimize loads from stable fields (marked w/ @Stable)")          \
1910                                                                             \
1911   product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC,                         \
1912           "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1913           "resolved before the bootstrap method is called; 1: when a BSM "  \
1914           "that may accept a BootstrapCallInfo is detected, use that API "  \
1915           "to pass BSM arguments, which allows the BSM to delay their "     \
1916           "resolution; 2+: stress test the BCI API by calling more BSMs "   \
1917           "via that API, instead of with the eagerly-resolved array.")      \
1918                                                                             \
1919   product(bool, PauseAtStartup,      false, DIAGNOSTIC,                     \
1920           "Causes the VM to pause at startup time and wait for the pause "  \
1921           "file to be removed (default: ./vm.paused.<pid>)")                \
1922                                                                             \
1923   product(ccstr, PauseAtStartupFile, NULL, DIAGNOSTIC,                      \
1924           "The file to create and for whose removal to await when pausing " \
1925           "at startup. (default: ./vm.paused.<pid>)")                       \
1926                                                                             \
1927   product(bool, PauseAtExit, false, DIAGNOSTIC,                             \
1928           "Pause and wait for keypress on exit if a debugger is attached")  \
1929                                                                             \
1930   product(bool, ExtendedDTraceProbes,    false,                             \
1931           "Enable performance-impacting dtrace probes")                     \
1932                                                                             \
1933   product(bool, DTraceMethodProbes, false,                                  \
1934           "Enable dtrace probes for method-entry and method-exit")          \
1935                                                                             \
1936   product(bool, DTraceAllocProbes, false,                                   \
1937           "Enable dtrace probes for object allocation")                     \
1938                                                                             \
1939   product(bool, DTraceMonitorProbes, false,                                 \
1940           "Enable dtrace probes for monitor events")                        \
1941                                                                             \
1942   product(bool, RelaxAccessControlCheck, false,                             \
1943           "Relax the access control checks in the verifier")                \
1944                                                                             \
1945   product(uintx, StringTableSize, defaultStringTableSize,                   \
1946           "Number of buckets in the interned String table "                 \
1947           "(will be rounded to nearest higher power of 2)")                 \
1948           range(minimumStringTableSize, 16777216ul /* 2^24 */)              \
1949                                                                             \
1950   product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL,     \
1951           "Number of buckets in the JVM internal Symbol table")             \
1952           range(minimumSymbolTableSize, 16777216ul /* 2^24 */)              \
1953                                                                             \
1954   product(bool, UseStringDeduplication, false,                              \
1955           "Use string deduplication")                                       \
1956                                                                             \
1957   product(uint, StringDeduplicationAgeThreshold, 3,                         \
1958           "A string must reach this age (or be promoted to an old region) " \
1959           "to be considered for deduplication")                             \
1960           range(1, markWord::max_age)                                       \
1961                                                                             \
1962   product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL,   \
1963           "Approximate initial number of buckets in the table")             \
1964           range(1, 1 * G)                                                   \
1965                                                                             \
1966   product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL,     \
1967           "Entries per bucket above which the table should be expanded")    \
1968           range(0.1, 1000.0)                                                \
1969                                                                             \
1970   product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL,    \
1971           "Entries per bucket below which the table should be shrunk")      \
1972           range(0.01, 100.0)                                                \
1973                                                                             \
1974   product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL,    \
1975           "Desired entries per bucket when resizing the table")             \
1976           range(0.01, 1000.0)                                               \
1977                                                                             \
1978   product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1979           "Minimum number of dead table entries for cleaning the table")    \
1980                                                                             \
1981   product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL,      \
1982           "Minimum percentage of dead table entries for cleaning the table") \
1983           range(1, 100)                                                     \
1984                                                                             \
1985   product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC,           \
1986           "Force more frequent table resizing")                             \
1987                                                                             \
1988   product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC,             \
1989           "Seed for the table hashing function; 0 requests computed seed")  \
1990                                                                             \
1991   product(bool, WhiteBoxAPI, false, DIAGNOSTIC,                             \
1992           "Enable internal testing APIs")                                   \
1993                                                                             \
1994   product(ccstr, DumpLoadedClassList, NULL,                                 \
1995           "Dump the names all loaded classes, that could be stored into "   \
1996           "the CDS archive, in the specified file")                         \
1997                                                                             \
1998   product(ccstr, SharedClassListFile, NULL,                                 \
1999           "Override the default CDS class list")                            \
2000                                                                             \
2001   product(ccstr, SharedArchiveFile, NULL,                                   \
2002           "Override the default location of the CDS archive file")          \
2003                                                                             \
2004   product(ccstr, ArchiveClassesAtExit, NULL,                                \
2005           "The path and name of the dynamic archive file")                  \
2006                                                                             \
2007   product(ccstr, ExtraSharedClassListFile, NULL,                            \
2008           "Extra classlist for building the CDS archive file")              \
2009                                                                             \
2010   product(intx, ArchiveRelocationMode, 1, DIAGNOSTIC,                       \
2011            "(0) first map at preferred address, and if "                    \
2012            "unsuccessful, map at alternative address; "                     \
2013            "(1) always map at alternative address (default); "              \
2014            "(2) always map at preferred address, and if unsuccessful, "     \
2015            "do not map the archive")                                        \
2016            range(0, 2)                                                      \
2017                                                                             \
2018   product(size_t, ArrayAllocatorMallocLimit, (size_t)-1, EXPERIMENTAL,      \
2019           "Allocation less than this value will be allocated "              \
2020           "using malloc. Larger allocations will use mmap.")                \
2021                                                                             \
2022   product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL,                  \
2023           "Accesses to all variables should always be atomic")              \
2024                                                                             \
2025   product(bool, UseUnalignedAccesses, false, DIAGNOSTIC,                    \
2026           "Use unaligned memory accesses in Unsafe")                        \
2027                                                                             \
2028   product_pd(bool, PreserveFramePointer,                                    \
2029              "Use the FP register for holding the frame pointer "           \
2030              "and not as a general purpose register.")                      \
2031                                                                             \
2032   product(size_t, AsyncLogBufferSize, 2*M,                                  \
2033           "Memory budget (in bytes) for the buffer of Asynchronous "        \
2034           "Logging (-Xlog:async).")                                         \
2035           range(100*K, 50*M)                                                \
2036                                                                             \
2037   product(bool, CheckIntrinsics, true, DIAGNOSTIC,                          \
2038              "When a class C is loaded, check that "                        \
2039              "(1) all intrinsics defined by the VM for class C are present "\
2040              "in the loaded class file and are marked with the "            \
2041              "@IntrinsicCandidate annotation, that "                        \
2042              "(2) there is an intrinsic registered for all loaded methods " \
2043              "that are annotated with the @IntrinsicCandidate annotation, " \
2044              "and that "                                                    \
2045              "(3) no orphan methods exist for class C (i.e., methods for "  \
2046              "which the VM declares an intrinsic but that are not declared "\
2047              "in the loaded class C. "                                      \
2048              "Check (3) is available only in debug builds.")                \
2049                                                                             \
2050   product_pd(intx, InitArrayShortSize, DIAGNOSTIC,                          \
2051           "Threshold small size (in bytes) for clearing arrays. "           \
2052           "Anything this size or smaller may get converted to discrete "    \
2053           "scalar stores.")                                                 \
2054           range(0, max_intx)                                                \
2055           constraint(InitArrayShortSizeConstraintFunc, AfterErgo)           \
2056                                                                             \
2057   product(ccstr, AllocateHeapAt, NULL,                                      \
2058           "Path to the directory where a temporary file will be created "   \
2059           "to use as the backing store for Java Heap.")                     \
2060                                                                             \
2061   develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0),       \
2062                "Run periodic metaspace verifications (0 - none, "           \
2063                "1 - always, >1 every nth interval)")                        \
2064                                                                             \
2065   product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC,                    \
2066           "On internal errors, include registers in error report.")         \
2067                                                                             \
2068   product(bool, UseSwitchProfiling, true, DIAGNOSTIC,                       \
2069           "leverage profiling for table/lookup switch")                     \
2070                                                                             \
2071   develop(bool, TraceMemoryWriteback, false,                                \
2072           "Trace memory writeback operations")                              \
2073                                                                             \
2074   JFR_ONLY(product(bool, FlightRecorder, false,                             \
2075           "(Deprecated) Enable Flight Recorder"))                           \
2076                                                                             \
2077   JFR_ONLY(product(ccstr, FlightRecorderOptions, NULL,                      \
2078           "Flight Recorder options"))                                       \
2079                                                                             \
2080   JFR_ONLY(product(ccstr, StartFlightRecording, NULL,                       \
2081           "Start flight recording with options"))                           \
2082                                                                             \
2083   product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL,            \
2084           "Use platform unstable time where supported for timestamps only") \
2085                                                                             \
2086   product(bool, UseEmptySlotsInSupers, true,                                \
2087                 "Allow allocating fields in empty slots of super-classes")  \
2088                                                                             \
2089   product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC,           \
2090                 "Make nmethod barriers deoptimise a lot.")                  \
2091                                                                             \
2092   develop(bool, VerifyCrossModifyFence,                                     \
2093           false AARCH64_ONLY(DEBUG_ONLY(||true)),                           \
2094              "Mark all threads after a safepoint, and clear on a modify "   \
2095              "fence. Add cleanliness checks.")                              \
2096                                                                             \
2097   develop(bool, TraceOptimizedUpcallStubs, false,                              \
2098                 "Trace optimized upcall stub generation")                      \
2099                                                                             \
2100   product(uint, TrimNativeHeapInterval, 0, EXPERIMENTAL,                    \
2101           "Interval, in ms, at which the JVM will trim the native heap if " \
2102           "the platform supports that. Lower values will reclaim memory "   \
2103           "more eagerly at the cost of higher overhead. A value of 0 "      \
2104           "(default) disables native heap trimming.")                       \
2105           range(0, UINT_MAX)                                                \
2106 
2107 // end of RUNTIME_FLAGS
2108 
2109 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2110 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2111 DECLARE_FLAGS(RUNTIME_FLAGS)
2112 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2113 
2114 #endif // SHARE_RUNTIME_GLOBALS_HPP