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