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