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, false,                          \
 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(intx, ObjectAlignmentInBytes, 8,                                  \
 133           "Default object alignment in bytes, 8 is minimum")                \
 134           range(8, 256)                                                     \
 135           constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
 136 
 137 #else
 138 // !_LP64
 139 
 140 #define LP64_RUNTIME_FLAGS(develop,                                         \
 141                            develop_pd,                                      \
 142                            product,                                         \
 143                            product_pd,                                      \
 144                            notproduct,                                      \
 145                            range,                                           \
 146                            constraint)
 147 const bool UseCompressedOops = false;
 148 const bool UseCompressedClassPointers = false;
 149 const intx ObjectAlignmentInBytes = 8;
 150 
 151 #endif // _LP64
 152 
 153 #define RUNTIME_FLAGS(develop,                                              \
 154                       develop_pd,                                           \
 155                       product,                                              \
 156                       product_pd,                                           \
 157                       notproduct,                                           \
 158                       range,                                                \
 159                       constraint)                                           \
 160                                                                             \
 161   notproduct(bool, CheckCompressedOops, true,                               \
 162           "Generate checks in encoding/decoding code in debug VM")          \
 163                                                                             \
 164   product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17),                        \
 165           "Heap allocation steps through preferred address regions to find" \
 166           " where it can allocate the heap. Number of steps to take per "   \
 167           "region.")                                                        \
 168           range(1, max_uintx)                                               \
 169                                                                             \
 170   product(uint, HandshakeTimeout, 0, DIAGNOSTIC,                            \
 171           "If nonzero set a timeout in milliseconds for handshakes")        \
 172                                                                             \
 173   product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL,                \
 174           "Force safe construction, as if all fields are final.")           \
 175                                                                             \
 176   product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC,         \
 177           "Enable normal processing of flags relating to field diagnostics")\
 178                                                                             \
 179   product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL,           \
 180           "Enable normal processing of flags relating to experimental "     \
 181           "features")                                                       \
 182                                                                             \
 183   product(bool, JavaMonitorsInStackTrace, true,                             \
 184           "Print information about Java monitor locks when the stacks are " \
 185           "dumped")                                                         \
 186                                                                             \
 187   product_pd(bool, UseLargePages,                                           \
 188           "Use large page memory")                                          \
 189                                                                             \
 190   product_pd(bool, UseLargePagesIndividualAllocation,                       \
 191           "Allocate large pages individually for better affinity")          \
 192                                                                             \
 193   develop(bool, LargePagesIndividualAllocationInjectError, false,           \
 194           "Fail large pages individual allocation")                         \
 195                                                                             \
 196   product(bool, UseNUMA, false,                                             \
 197           "Use NUMA if available")                                          \
 198                                                                             \
 199   product(bool, UseNUMAInterleaving, false,                                 \
 200           "Interleave memory across NUMA nodes if available")               \
 201                                                                             \
 202   product(size_t, NUMAInterleaveGranularity, 2*M,                           \
 203           "Granularity to use for NUMA interleaving on Windows OS")         \
 204           constraint(NUMAInterleaveGranularityConstraintFunc, AtParse)      \
 205                                                                             \
 206   product(uintx, NUMAChunkResizeWeight, 20,                                 \
 207           "Percentage (0-100) used to weight the current sample when "      \
 208           "computing exponentially decaying average for "                   \
 209           "AdaptiveNUMAChunkSizing")                                        \
 210           range(0, 100)                                                     \
 211                                                                             \
 212   product(size_t, NUMASpaceResizeRate, 1*G,                                 \
 213           "Do not reallocate more than this amount per collection")         \
 214           range(0, max_uintx)                                               \
 215                                                                             \
 216   product(bool, UseAdaptiveNUMAChunkSizing, true,                           \
 217           "Enable adaptive chunk sizing for NUMA")                          \
 218                                                                             \
 219   product(bool, NUMAStats, false,                                           \
 220           "Print NUMA stats in detailed heap information")                  \
 221                                                                             \
 222   product(uintx, NUMAPageScanRate, 256,                                     \
 223           "Maximum number of pages to include in the page scan procedure")  \
 224           range(0, max_uintx)                                               \
 225                                                                             \
 226   product(bool, UseAES, false,                                              \
 227           "Control whether AES instructions are used when available")       \
 228                                                                             \
 229   product(bool, UseFMA, false,                                              \
 230           "Control whether FMA instructions are used when available")       \
 231                                                                             \
 232   product(bool, UseSHA, false,                                              \
 233           "Control whether SHA instructions are used when available")       \
 234                                                                             \
 235   product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC,                      \
 236           "Use intrinsics for GHASH versions of crypto")                    \
 237                                                                             \
 238   product(bool, UseBASE64Intrinsics, false,                                 \
 239           "Use intrinsics for java.util.Base64")                            \
 240                                                                             \
 241   product(size_t, LargePageSizeInBytes, 0,                                  \
 242           "Maximum large page size used (0 will use the default large "     \
 243           "page size for the environment as the maximum)")                  \
 244           range(0, max_uintx)                                               \
 245                                                                             \
 246   product(size_t, LargePageHeapSizeThreshold, 128*M,                        \
 247           "Use large pages if maximum heap is at least this big")           \
 248           range(0, max_uintx)                                               \
 249                                                                             \
 250   product(bool, ForceTimeHighResolution, false,                             \
 251           "Using high time resolution (for Win32 only)")                    \
 252                                                                             \
 253   develop(bool, TracePcPatching, false,                                     \
 254           "Trace usage of frame::patch_pc")                                 \
 255                                                                             \
 256   develop(bool, TraceRelocator, false,                                      \
 257           "Trace the bytecode relocator")                                   \
 258                                                                             \
 259                                                                             \
 260   product(bool, SafepointALot, false, DIAGNOSTIC,                           \
 261           "Generate a lot of safepoints. This works with "                  \
 262           "GuaranteedSafepointInterval")                                    \
 263                                                                             \
 264   product(bool, HandshakeALot, false, DIAGNOSTIC,                           \
 265           "Generate a lot of handshakes. This works with "                  \
 266           "GuaranteedSafepointInterval")                                    \
 267                                                                             \
 268   product_pd(bool, BackgroundCompilation,                                   \
 269           "A thread requesting compilation is not blocked during "          \
 270           "compilation")                                                    \
 271                                                                             \
 272   product(bool, MethodFlushing, true,                                       \
 273           "Reclamation of zombie and not-entrant methods")                  \
 274                                                                             \
 275   develop(bool, VerifyStack, false,                                         \
 276           "Verify stack of each thread when it is entering a runtime call") \
 277                                                                             \
 278   product(bool, ForceUnreachable, false, DIAGNOSTIC,                        \
 279           "Make all non code cache addresses to be unreachable by "         \
 280           "forcing use of 64bit literal fixups")                            \
 281                                                                             \
 282   develop(bool, TraceDerivedPointers, false,                                \
 283           "Trace traversal of derived pointers on stack")                   \
 284                                                                             \
 285   notproduct(bool, TraceCodeBlobStacks, false,                              \
 286           "Trace stack-walk of codeblobs")                                  \
 287                                                                             \
 288   notproduct(bool, PrintRewrites, false,                                    \
 289           "Print methods that are being rewritten")                         \
 290                                                                             \
 291   product(bool, UseInlineCaches, true,                                      \
 292           "Use Inline Caches for virtual calls ")                           \
 293                                                                             \
 294   product(bool, InlineArrayCopy, true, DIAGNOSTIC,                          \
 295           "Inline arraycopy native that is known to be part of "            \
 296           "base library DLL")                                               \
 297                                                                             \
 298   product(bool, InlineObjectHash, true, DIAGNOSTIC,                         \
 299           "Inline Object::hashCode() native that is known to be part "      \
 300           "of base library DLL")                                            \
 301                                                                             \
 302   product(bool, InlineNatives, true, DIAGNOSTIC,                            \
 303           "Inline natives that are known to be part of base library DLL")   \
 304                                                                             \
 305   product(bool, InlineMathNatives, true, DIAGNOSTIC,                        \
 306           "Inline SinD, CosD, etc.")                                        \
 307                                                                             \
 308   product(bool, InlineClassNatives, true, DIAGNOSTIC,                       \
 309           "Inline Class.isInstance, etc")                                   \
 310                                                                             \
 311   product(bool, InlineThreadNatives, true, DIAGNOSTIC,                      \
 312           "Inline Thread.currentThread, etc")                               \
 313                                                                             \
 314   product(bool, InlineUnsafeOps, true, DIAGNOSTIC,                          \
 315           "Inline memory ops (native methods) from Unsafe")                 \
 316                                                                             \
 317   product(bool, CriticalJNINatives, false,                                  \
 318           "(Deprecated) Check for critical JNI entry points")               \
 319                                                                             \
 320   product(bool, UseAESIntrinsics, false, DIAGNOSTIC,                        \
 321           "Use intrinsics for AES versions of crypto")                      \
 322                                                                             \
 323   product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC,                     \
 324           "Use intrinsics for the paralleled version of AES/CTR crypto")    \
 325                                                                             \
 326   product(bool, UseMD5Intrinsics, false, DIAGNOSTIC,                        \
 327           "Use intrinsics for MD5 crypto hash function")                    \
 328                                                                             \
 329   product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC,                       \
 330           "Use intrinsics for SHA-1 crypto hash function. "                 \
 331           "Requires that UseSHA is enabled.")                               \
 332                                                                             \
 333   product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC,                     \
 334           "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. "  \
 335           "Requires that UseSHA is enabled.")                               \
 336                                                                             \
 337   product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC,                     \
 338           "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. "  \
 339           "Requires that UseSHA is enabled.")                               \
 340                                                                             \
 341   product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC,                       \
 342           "Use intrinsics for SHA3 crypto hash function. "                  \
 343           "Requires that UseSHA is enabled.")                               \
 344                                                                             \
 345   product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC,                      \
 346           "use intrinsics for java.util.zip.CRC32")                         \
 347                                                                             \
 348   product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC,                     \
 349           "use intrinsics for java.util.zip.CRC32C")                        \
 350                                                                             \
 351   product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC,                    \
 352           "use intrinsics for java.util.zip.Adler32")                       \
 353                                                                             \
 354   product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC,          \
 355           "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
 356                                                                             \
 357   product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC,                    \
 358           "Enables intrinsification of Math.copySign")                      \
 359                                                                             \
 360   product(bool, UseSignumIntrinsic, false, DIAGNOSTIC,                      \
 361           "Enables intrinsification of Math.signum")                        \
 362                                                                             \
 363   product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC,                      \
 364          "do not expand intrinsics whose (internal) names appear here")     \
 365          constraint(DisableIntrinsicConstraintFunc,AfterErgo)               \
 366                                                                             \
 367   product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC,                      \
 368          "Control intrinsics using a list of +/- (internal) names, "        \
 369          "separated by commas")                                             \
 370          constraint(ControlIntrinsicConstraintFunc,AfterErgo)               \
 371                                                                             \
 372   develop(bool, TraceCallFixup, false,                                      \
 373           "Trace all call fixups")                                          \
 374                                                                             \
 375   develop(bool, DeoptimizeALot, false,                                      \
 376           "Deoptimize at every exit from the runtime system")               \
 377                                                                             \
 378   notproduct(ccstrlist, DeoptimizeOnlyAt, "",                               \
 379           "A comma separated list of bcis to deoptimize at")                \
 380                                                                             \
 381   develop(bool, DeoptimizeRandom, false,                                    \
 382           "Deoptimize random frames on random exit from the runtime system")\
 383                                                                             \
 384   notproduct(bool, ZombieALot, false,                                       \
 385           "Create zombies (non-entrant) at exit from the runtime system")   \
 386                                                                             \
 387   notproduct(bool, WalkStackALot, false,                                    \
 388           "Trace stack (no print) at every exit from the runtime system")   \
 389                                                                             \
 390   develop(bool, DeoptimizeObjectsALot, false,                               \
 391           "For testing purposes concurrent threads revert optimizations "   \
 392           "based on escape analysis at intervals given with "               \
 393           "DeoptimizeObjectsALotInterval=n. The thread count is given "     \
 394           "with DeoptimizeObjectsALotThreadCountSingle and "                \
 395           "DeoptimizeObjectsALotThreadCountAll.")                           \
 396                                                                             \
 397   develop(uint64_t, DeoptimizeObjectsALotInterval, 5,                       \
 398           "Interval for DeoptimizeObjectsALot.")                            \
 399           range(0, max_jlong)                                               \
 400                                                                             \
 401   develop(int, DeoptimizeObjectsALotThreadCountSingle, 1,                   \
 402           "The number of threads that revert optimizations based on "       \
 403           "escape analysis for a single thread if DeoptimizeObjectsALot "   \
 404           "is enabled. The target thread is selected round robin." )        \
 405           range(0, max_jint)                                                \
 406                                                                             \
 407   develop(int, DeoptimizeObjectsALotThreadCountAll, 1,                      \
 408           "The number of threads that revert optimizations based on "       \
 409           "escape analysis for all threads if DeoptimizeObjectsALot "       \
 410           "is enabled." )                                                   \
 411           range(0, max_jint)                                                \
 412                                                                             \
 413   notproduct(bool, VerifyLastFrame, false,                                  \
 414           "Verify oops on last frame on entry to VM")                       \
 415                                                                             \
 416   product(bool, SafepointTimeout, false,                                    \
 417           "Time out and warn or fail after SafepointTimeoutDelay "          \
 418           "milliseconds if failed to reach safepoint")                      \
 419                                                                             \
 420   product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC,               \
 421           "Abort upon failure to reach safepoint (see SafepointTimeout)")   \
 422                                                                             \
 423   product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC,             \
 424           "Abort upon failure to complete VM operation promptly")           \
 425                                                                             \
 426   product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC,         \
 427           "Delay in milliseconds for option AbortVMOnVMOperationTimeout")   \
 428           range(0, max_intx)                                                \
 429                                                                             \
 430   product(bool, MaxFDLimit, true,                                           \
 431           "Bump the number of file descriptors to maximum (Unix only)")     \
 432                                                                             \
 433   product(bool, LogEvents, true, DIAGNOSTIC,                                \
 434           "Enable the various ring buffer event logs")                      \
 435                                                                             \
 436   product(uintx, LogEventsBufferEntries, 20, DIAGNOSTIC,                    \
 437           "Number of ring buffer event logs")                               \
 438           range(1, NOT_LP64(1*K) LP64_ONLY(1*M))                            \
 439                                                                             \
 440   product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC,               \
 441           "Enable the Java bytecode verifier for remote classes")           \
 442                                                                             \
 443   product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC,               \
 444           "Enable the Java bytecode verifier for local classes")            \
 445                                                                             \
 446   develop(bool, VerifyStackAtCalls, false,                                  \
 447           "Verify that the stack pointer is unchanged after calls")         \
 448                                                                             \
 449   develop(bool, TraceJavaAssertions, false,                                 \
 450           "Trace java language assertions")                                 \
 451                                                                             \
 452   notproduct(bool, VerifyCodeCache, false,                                  \
 453           "Verify code cache on memory allocation/deallocation")            \
 454                                                                             \
 455   develop(bool, UseMallocOnly, false,                                       \
 456           "Use only malloc/free for allocation (no resource area/arena). "  \
 457           "Used to help diagnose memory stomping bugs.")                    \
 458                                                                             \
 459   develop(bool, ZapResourceArea, trueInDebug,                               \
 460           "Zap freed resource/arena space")                                 \
 461                                                                             \
 462   notproduct(bool, ZapVMHandleArea, trueInDebug,                            \
 463           "Zap freed VM handle space")                                      \
 464                                                                             \
 465   notproduct(bool, ZapStackSegments, trueInDebug,                           \
 466           "Zap allocated/freed stack segments")                             \
 467                                                                             \
 468   develop(bool, ZapUnusedHeapArea, trueInDebug,                             \
 469           "Zap unused heap space")                                          \
 470                                                                             \
 471   develop(bool, CheckZapUnusedHeapArea, false,                              \
 472           "Check zapping of unused heap space")                             \
 473                                                                             \
 474   develop(bool, ZapFillerObjects, trueInDebug,                              \
 475           "Zap filler objects")                                             \
 476                                                                             \
 477   product(bool, ExecutingUnitTests, false,                                  \
 478           "Whether the JVM is running unit tests or not")                   \
 479                                                                             \
 480   develop(uintx, ErrorHandlerTest, 0,                                       \
 481           "If > 0, provokes an error after VM initialization; the value "   \
 482           "determines which error to provoke. See controlled_crash() "      \
 483           "in vmError.cpp.")                                                \
 484           range(0, 17)                                                      \
 485                                                                             \
 486   develop(uintx, TestCrashInErrorHandler, 0,                                \
 487           "If > 0, provokes an error inside VM error handler (a secondary " \
 488           "crash). see controlled_crash() in vmError.cpp")                  \
 489           range(0, 17)                                                      \
 490                                                                             \
 491   develop(bool, TestSafeFetchInErrorHandler, false   ,                      \
 492           "If true, tests SafeFetch inside error handler.")                 \
 493                                                                             \
 494   develop(bool, TestUnresponsiveErrorHandler, false,                        \
 495           "If true, simulates an unresponsive error handler.")              \
 496                                                                             \
 497   develop(bool, Verbose, false,                                             \
 498           "Print additional debugging information from other modes")        \
 499                                                                             \
 500   develop(bool, PrintMiscellaneous, false,                                  \
 501           "Print uncategorized debugging information (requires +Verbose)")  \
 502                                                                             \
 503   develop(bool, WizardMode, false,                                          \
 504           "Print much more debugging information")                          \
 505                                                                             \
 506   product(bool, ShowMessageBoxOnError, false,                               \
 507           "Keep process alive on VM fatal error")                           \
 508                                                                             \
 509   product(bool, CreateCoredumpOnCrash, true,                                \
 510           "Create core/mini dump on VM fatal error")                        \
 511                                                                             \
 512   product(uint64_t, ErrorLogTimeout, 2 * 60,                                \
 513           "Timeout, in seconds, to limit the time spent on writing an "     \
 514           "error log in case of a crash.")                                  \
 515           range(0, (uint64_t)max_jlong/1000)                                \
 516                                                                             \
 517   product(bool, SuppressFatalErrorMessage, false,                           \
 518           "Report NO fatal error message (avoid deadlock)")                 \
 519                                                                             \
 520   product(ccstrlist, OnError, "",                                           \
 521           "Run user-defined commands on fatal error; see VMError.cpp "      \
 522           "for examples")                                                   \
 523                                                                             \
 524   product(ccstrlist, OnOutOfMemoryError, "",                                \
 525           "Run user-defined commands on first java.lang.OutOfMemoryError "  \
 526           "thrown from JVM")                                                \
 527                                                                             \
 528   product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE,                    \
 529           "Dump heap to file before any major stop-the-world GC")           \
 530                                                                             \
 531   product(bool, HeapDumpAfterFullGC, false, MANAGEABLE,                     \
 532           "Dump heap to file after any major stop-the-world GC")            \
 533                                                                             \
 534   product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE,              \
 535           "Dump heap to file when java.lang.OutOfMemoryError is thrown "    \
 536           "from JVM")                                                       \
 537                                                                             \
 538   product(ccstr, HeapDumpPath, NULL, MANAGEABLE,                            \
 539           "When HeapDumpOnOutOfMemoryError is on, the path (filename or "   \
 540           "directory) of the dump file (defaults to java_pid<pid>.hprof "   \
 541           "in the working directory)")                                      \
 542                                                                             \
 543   product(intx, HeapDumpGzipLevel, 0, MANAGEABLE,                           \
 544           "When HeapDumpOnOutOfMemoryError is on, the gzip compression "    \
 545           "level of the dump file. 0 (the default) disables gzip "          \
 546           "compression. Otherwise the level must be between 1 and 9.")      \
 547           range(0, 9)                                                       \
 548                                                                             \
 549   product(ccstr, NativeMemoryTracking, "off",                               \
 550           "Native memory tracking options")                                 \
 551                                                                             \
 552   product(bool, PrintNMTStatistics, false, DIAGNOSTIC,                      \
 553           "Print native memory tracking summary data if it is on")          \
 554                                                                             \
 555   product(bool, LogCompilation, false, DIAGNOSTIC,                          \
 556           "Log compilation activity in detail to LogFile")                  \
 557                                                                             \
 558   product(bool, PrintCompilation, false,                                    \
 559           "Print compilations")                                             \
 560                                                                             \
 561   product(intx, RepeatCompilation, 0, DIAGNOSTIC,                           \
 562           "Repeat compilation without installing code (number of times)")   \
 563           range(0, max_jint)                                                \
 564                                                                             \
 565   product(bool, PrintExtendedThreadInfo, false,                             \
 566           "Print more information in thread dump")                          \
 567                                                                             \
 568   product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC,                         \
 569           "0: do not allow scavengable oops in the code cache; "            \
 570           "1: allow scavenging from the code cache; "                       \
 571           "2: emit as many constants as the compiler can see")              \
 572           range(0, 2)                                                       \
 573                                                                             \
 574   product(bool, AlwaysRestoreFPU, false,                                    \
 575           "Restore the FPU control word after every JNI call (expensive)")  \
 576                                                                             \
 577   product(bool, PrintCompilation2, false, DIAGNOSTIC,                       \
 578           "Print additional statistics per compilation")                    \
 579                                                                             \
 580   product(bool, PrintAdapterHandlers, false, DIAGNOSTIC,                    \
 581           "Print code generated for i2c/c2i adapters")                      \
 582                                                                             \
 583   product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC,                \
 584           "Verify that i2c/c2i adapters are called properly")               \
 585                                                                             \
 586   develop(bool, VerifyAdapterSharing, false,                                \
 587           "Verify that the code for shared adapters is the equivalent")     \
 588                                                                             \
 589   product(bool, PrintAssembly, false, DIAGNOSTIC,                           \
 590           "Print assembly code (using external disassembler.so)")           \
 591                                                                             \
 592   product(ccstr, PrintAssemblyOptions, NULL, DIAGNOSTIC,                    \
 593           "Print options string passed to disassembler.so")                 \
 594                                                                             \
 595   notproduct(bool, PrintNMethodStatistics, false,                           \
 596           "Print a summary statistic for the generated nmethods")           \
 597                                                                             \
 598   product(bool, PrintNMethods, false, DIAGNOSTIC,                           \
 599           "Print assembly code for nmethods when generated")                \
 600                                                                             \
 601   product(bool, PrintNativeNMethods, false, DIAGNOSTIC,                     \
 602           "Print assembly code for native nmethods when generated")         \
 603                                                                             \
 604   develop(bool, PrintDebugInfo, false,                                      \
 605           "Print debug information for all nmethods when generated")        \
 606                                                                             \
 607   develop(bool, PrintRelocations, false,                                    \
 608           "Print relocation information for all nmethods when generated")   \
 609                                                                             \
 610   develop(bool, PrintDependencies, false,                                   \
 611           "Print dependency information for all nmethods when generated")   \
 612                                                                             \
 613   develop(bool, PrintExceptionHandlers, false,                              \
 614           "Print exception handler tables for all nmethods when generated") \
 615                                                                             \
 616   develop(bool, StressCompiledExceptionHandlers, false,                     \
 617           "Exercise compiled exception handlers")                           \
 618                                                                             \
 619   develop(bool, InterceptOSException, false,                                \
 620           "Start debugger when an implicit OS (e.g. NULL) "                 \
 621           "exception happens")                                              \
 622                                                                             \
 623   product(bool, PrintCodeCache, false,                                      \
 624           "Print the code cache memory usage when exiting")                 \
 625                                                                             \
 626   develop(bool, PrintCodeCache2, false,                                     \
 627           "Print detailed usage information on the code cache when exiting")\
 628                                                                             \
 629   product(bool, PrintCodeCacheOnCompilation, false,                         \
 630           "Print the code cache memory usage each time a method is "        \
 631           "compiled")                                                       \
 632                                                                             \
 633   product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC,                  \
 634           "Print code heap usage statistics on exit and on full condition") \
 635                                                                             \
 636   product(bool, PrintStubCode, false, DIAGNOSTIC,                           \
 637           "Print generated stub code")                                      \
 638                                                                             \
 639   product(bool, StackTraceInThrowable, true,                                \
 640           "Collect backtrace in throwable when exception happens")          \
 641                                                                             \
 642   product(bool, OmitStackTraceInFastThrow, true,                            \
 643           "Omit backtraces for some 'hot' exceptions in optimized code")    \
 644                                                                             \
 645   product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE,       \
 646           "Show exception messages from RuntimeExceptions that contain "    \
 647           "snippets of the failing code. Disable this to improve privacy.") \
 648                                                                             \
 649   product(bool, PrintWarnings, true,                                        \
 650           "Print JVM warnings to output stream")                            \
 651                                                                             \
 652   product(bool, RegisterFinalizersAtInit, true,                             \
 653           "Register finalizable objects at end of Object.<init> or "        \
 654           "after allocation")                                               \
 655                                                                             \
 656   develop(bool, RegisterReferences, true,                                   \
 657           "Tell whether the VM should register soft/weak/final/phantom "    \
 658           "references")                                                     \
 659                                                                             \
 660   develop(bool, PrintCodeCacheExtension, false,                             \
 661           "Print extension of code cache")                                  \
 662                                                                             \
 663   develop(bool, UsePrivilegedStack, true,                                   \
 664           "Enable the security JVM functions")                              \
 665                                                                             \
 666   product(bool, ClassUnloading, true,                                       \
 667           "Do unloading of classes")                                        \
 668                                                                             \
 669   product(bool, ClassUnloadingWithConcurrentMark, true,                     \
 670           "Do unloading of classes with a concurrent marking cycle")        \
 671                                                                             \
 672   notproduct(bool, PrintSystemDictionaryAtExit, false,                      \
 673           "Print the system dictionary at exit")                            \
 674                                                                             \
 675   notproduct(bool, PrintClassLoaderDataGraphAtExit, false,                  \
 676           "Print the class loader data graph at exit")                      \
 677                                                                             \
 678   product(bool, DynamicallyResizeSystemDictionaries, true, DIAGNOSTIC,      \
 679           "Dynamically resize system dictionaries as needed")               \
 680                                                                             \
 681   product(bool, AllowParallelDefineClass, false,                            \
 682           "Allow parallel defineClass requests for class loaders "          \
 683           "registering as parallel capable")                                \
 684                                                                             \
 685   product_pd(bool, DontYieldALot,                                           \
 686           "Throw away obvious excess yield calls")                          \
 687                                                                             \
 688   product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL,     \
 689                "Disable the use of stack guard pages if the JVM is loaded " \
 690                "on the primordial process thread")                          \
 691                                                                             \
 692   /* notice: the max range value here is max_jint, not max_intx  */         \
 693   /* because of overflow issue                                   */         \
 694   product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC,                    \
 695           "Async deflate idle monitors every so many milliseconds when "    \
 696           "MonitorUsedDeflationThreshold is exceeded (0 is off).")          \
 697           range(0, max_jint)                                                \
 698                                                                             \
 699   product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC,           \
 700           "Used to estimate a variable ceiling based on number of threads " \
 701           "for use with MonitorUsedDeflationThreshold (0 is off).")         \
 702           range(0, max_uintx)                                               \
 703                                                                             \
 704   /* notice: the max range value here is max_jint, not max_intx  */         \
 705   /* because of overflow issue                                   */         \
 706   product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC,                   \
 707           "The maximum number of monitors to deflate, unlink and delete "   \
 708           "at one time (minimum is 1024).")                      \
 709           range(1024, max_jint)                                             \
 710                                                                             \
 711   product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC,              \
 712           "Percentage of used monitors before triggering deflation (0 is "  \
 713           "off). The check is performed on GuaranteedSafepointInterval "    \
 714           "or AsyncDeflationInterval.")                                     \
 715           range(0, 100)                                                     \
 716                                                                             \
 717   product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC,                \
 718           "Max number of no progress async deflation attempts to tolerate " \
 719           "before adjusting the in_use_list_ceiling up (0 is off).")        \
 720           range(0, max_uintx)                                               \
 721                                                                             \
 722   product(intx, hashCode, 5, EXPERIMENTAL,                                  \
 723                "(Unstable) select hashCode generation algorithm")           \
 724                                                                             \
 725   product(bool, FilterSpuriousWakeups, true,                                \
 726           "(Deprecated) When true prevents OS-level spurious, or premature,"\
 727           " wakeups from Object.wait (Ignored for Windows)")                \
 728                                                                             \
 729   product(bool, ReduceSignalUsage, false,                                   \
 730           "Reduce the use of OS signals in Java and/or the VM")             \
 731                                                                             \
 732   develop(bool, LoadLineNumberTables, true,                                 \
 733           "Tell whether the class file parser loads line number tables")    \
 734                                                                             \
 735   develop(bool, LoadLocalVariableTables, true,                              \
 736           "Tell whether the class file parser loads local variable tables") \
 737                                                                             \
 738   develop(bool, LoadLocalVariableTypeTables, true,                          \
 739           "Tell whether the class file parser loads local variable type"    \
 740           "tables")                                                         \
 741                                                                             \
 742   product(bool, AllowUserSignalHandlers, false,                             \
 743           "Application will install primary signal handlers for the JVM "   \
 744           "(Unix only)")                                                    \
 745                                                                             \
 746   product(bool, UseSignalChaining, true,                                    \
 747           "Use signal-chaining to invoke signal handlers installed "        \
 748           "by the application (Unix only)")                                 \
 749                                                                             \
 750   product(bool, RestoreMXCSROnJNICalls, false,                              \
 751           "Restore MXCSR when returning from JNI calls")                    \
 752                                                                             \
 753   product(bool, CheckJNICalls, false,                                       \
 754           "Verify all arguments to JNI calls")                              \
 755                                                                             \
 756   product(bool, UseFastJNIAccessors, true,                                  \
 757           "Use optimized versions of Get<Primitive>Field")                  \
 758                                                                             \
 759   product(intx, MaxJNILocalCapacity, 65536,                                 \
 760           "Maximum allowable local JNI handle capacity to "                 \
 761           "EnsureLocalCapacity() and PushLocalFrame(), "                    \
 762           "where <= 0 is unlimited, default: 65536")                        \
 763           range(min_intx, max_intx)                                         \
 764                                                                             \
 765   product(bool, EagerXrunInit, false,                                       \
 766           "Eagerly initialize -Xrun libraries; allows startup profiling, "  \
 767           "but not all -Xrun libraries may support the state of the VM "    \
 768           "at this time")                                                   \
 769                                                                             \
 770   product(bool, PreserveAllAnnotations, false,                              \
 771           "Preserve RuntimeInvisibleAnnotations as well "                   \
 772           "as RuntimeVisibleAnnotations")                                   \
 773                                                                             \
 774   develop(uintx, PreallocatedOutOfMemoryErrorCount, 4,                      \
 775           "Number of OutOfMemoryErrors preallocated with backtrace")        \
 776                                                                             \
 777   product(bool, UseXMMForArrayCopy, false,                                  \
 778           "Use SSE2 MOVQ instruction for Arraycopy")                        \
 779                                                                             \
 780   notproduct(bool, PrintFieldLayout, false,                                 \
 781           "Print field layout for each class")                              \
 782                                                                             \
 783   /* Need to limit the extent of the padding to reasonable size.          */\
 784   /* 8K is well beyond the reasonable HW cache line size, even with       */\
 785   /* aggressive prefetching, while still leaving the room for segregating */\
 786   /* among the distinct pages.                                            */\
 787   product(intx, ContendedPaddingWidth, 128,                                 \
 788           "How many bytes to pad the fields/classes marked @Contended with")\
 789           range(0, 8192)                                                    \
 790           constraint(ContendedPaddingWidthConstraintFunc,AfterErgo)         \
 791                                                                             \
 792   product(bool, EnableContended, true,                                      \
 793           "Enable @Contended annotation support")                           \
 794                                                                             \
 795   product(bool, RestrictContended, true,                                    \
 796           "Restrict @Contended to trusted classes")                         \
 797                                                                             \
 798   product(intx, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC,             \
 799              "Detect and take action upon identifying synchronization on "  \
 800              "value based classes. Modes: "                                 \
 801              "0: off; "                                                     \
 802              "1: exit with fatal error; "                                   \
 803              "2: log message to stdout. Output file can be specified with " \
 804              "   -Xlog:valuebasedclasses. If JFR is running it will "       \
 805              "   also generate JFR events.")                                \
 806              range(0, 2)                                                    \
 807                                                                             \
 808   product(bool, ExitOnOutOfMemoryError, false,                              \
 809           "JVM exits on the first occurrence of an out-of-memory error "    \
 810           "thrown from JVM")                                                \
 811                                                                             \
 812   product(bool, CrashOnOutOfMemoryError, false,                             \
 813           "JVM aborts, producing an error log and core/mini dump, on the "  \
 814           "first occurrence of an out-of-memory error thrown from JVM")     \
 815                                                                             \
 816   product(bool, DetectLocksInCompiledFrames, true,                          \
 817           "Detect monitors in continuation compiled frames")                \
 818                                                                             \
 819   /* tracing */                                                             \
 820                                                                             \
 821   develop(bool, StressRewriter, false,                                      \
 822           "Stress linktime bytecode rewriting")                             \
 823                                                                             \
 824   product(ccstr, TraceJVMTI, NULL,                                          \
 825           "Trace flags for JVMTI functions and events")                     \
 826                                                                             \
 827   product(bool, StressLdcRewrite, false, DIAGNOSTIC,                        \
 828           "Force ldc -> ldc_w rewrite during RedefineClasses. "             \
 829           "This option can change an EMCP method into an obsolete method "  \
 830           "and can affect tests that expect specific methods to be EMCP. "  \
 831           "This option should be used with caution.")                       \
 832                                                                             \
 833   product(bool, AllowRedefinitionToAddDeleteMethods, false,                 \
 834           "(Deprecated) Allow redefinition to add and delete private "      \
 835           "static or final methods for compatibility with old releases")    \
 836                                                                             \
 837   develop(bool, TraceBytecodes, false,                                      \
 838           "Trace bytecode execution")                                       \
 839                                                                             \
 840   develop(bool, TraceICs, false,                                            \
 841           "Trace inline cache changes")                                     \
 842                                                                             \
 843   notproduct(bool, TraceInvocationCounterOverflow, false,                   \
 844           "Trace method invocation counter overflow")                       \
 845                                                                             \
 846   develop(bool, TraceInlineCacheClearing, false,                            \
 847           "Trace clearing of inline caches in nmethods")                    \
 848                                                                             \
 849   develop(bool, TraceDependencies, false,                                   \
 850           "Trace dependencies")                                             \
 851                                                                             \
 852   develop(bool, VerifyDependencies, trueInDebug,                            \
 853           "Exercise and verify the compilation dependency mechanism")       \
 854                                                                             \
 855   develop(bool, TraceNewOopMapGeneration, false,                            \
 856           "Trace OopMapGeneration")                                         \
 857                                                                             \
 858   develop(bool, TraceNewOopMapGenerationDetailed, false,                    \
 859           "Trace OopMapGeneration: print detailed cell states")             \
 860                                                                             \
 861   develop(bool, TimeOopMap, false,                                          \
 862           "Time calls to GenerateOopMap::compute_map() in sum")             \
 863                                                                             \
 864   develop(bool, TimeOopMap2, false,                                         \
 865           "Time calls to GenerateOopMap::compute_map() individually")       \
 866                                                                             \
 867   develop(bool, TraceOopMapRewrites, false,                                 \
 868           "Trace rewriting of methods during oop map generation")           \
 869                                                                             \
 870   develop(bool, TraceICBuffer, false,                                       \
 871           "Trace usage of IC buffer")                                       \
 872                                                                             \
 873   develop(bool, TraceCompiledIC, false,                                     \
 874           "Trace changes of compiled IC")                                   \
 875                                                                             \
 876   develop(bool, FLSVerifyDictionary, false,                                 \
 877           "Do lots of (expensive) FLS dictionary verification")             \
 878                                                                             \
 879                                                                             \
 880   notproduct(bool, CheckMemoryInitialization, false,                        \
 881           "Check memory initialization")                                    \
 882                                                                             \
 883   product(uintx, ProcessDistributionStride, 4,                              \
 884           "Stride through processors when distributing processes")          \
 885           range(0, max_juint)                                               \
 886                                                                             \
 887   develop(bool, TraceFinalizerRegistration, false,                          \
 888           "Trace registration of final references")                         \
 889                                                                             \
 890   product(bool, IgnoreEmptyClassPaths, false,                               \
 891           "Ignore empty path elements in -classpath")                       \
 892                                                                             \
 893   product(bool, PrintHeapAtSIGBREAK, true,                                  \
 894           "Print heap layout in response to SIGBREAK")                      \
 895                                                                             \
 896   product(bool, PrintClassHistogram, false, MANAGEABLE,                     \
 897           "Print a histogram of class instances")                           \
 898                                                                             \
 899   product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL,              \
 900           "The percentage of the used heap that the instances of a class "  \
 901           "must occupy for the class to generate a trace event")            \
 902           range(0.0, 100.0)                                                 \
 903                                                                             \
 904   /* JVMTI heap profiling */                                                \
 905                                                                             \
 906   product(bool, VerifyBeforeIteration, false, DIAGNOSTIC,                   \
 907           "Verify memory system before JVMTI iteration")                    \
 908                                                                             \
 909   /* compiler */                                                            \
 910                                                                             \
 911   /* notice: the max range value here is max_jint, not max_intx  */         \
 912   /* because of overflow issue                                   */         \
 913   product(intx, CICompilerCount, CI_COMPILER_COUNT,                         \
 914           "Number of compiler threads to run")                              \
 915           range(0, max_jint)                                                \
 916           constraint(CICompilerCountConstraintFunc, AfterErgo)              \
 917                                                                             \
 918   product(bool, UseDynamicNumberOfCompilerThreads, true,                    \
 919           "Dynamically choose the number of parallel compiler threads")     \
 920                                                                             \
 921   product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC,            \
 922              "Reduce the number of parallel compiler threads when they "    \
 923              "are not used")                                                \
 924                                                                             \
 925   product(bool, TraceCompilerThreads, false, DIAGNOSTIC,                    \
 926              "Trace creation and removal of compiler threads")              \
 927                                                                             \
 928   develop(bool, InjectCompilerCreationFailure, false,                       \
 929           "Inject thread creation failures for "                            \
 930           "UseDynamicNumberOfCompilerThreads")                              \
 931                                                                             \
 932   develop(bool, GenerateSynchronizationCode, true,                          \
 933           "generate locking/unlocking code for synchronized methods and "   \
 934           "monitors")                                                       \
 935                                                                             \
 936   develop(bool, GenerateRangeChecks, true,                                  \
 937           "Generate range checks for array accesses")                       \
 938                                                                             \
 939   product_pd(bool, ImplicitNullChecks, DIAGNOSTIC,                          \
 940           "Generate code for implicit null checks")                         \
 941                                                                             \
 942   product_pd(bool, TrapBasedNullChecks,                                     \
 943           "Generate code for null checks that uses a cmp and trap "         \
 944           "instruction raising SIGTRAP.  This is only used if an access to" \
 945           "null (+offset) will not raise a SIGSEGV, i.e.,"                  \
 946           "ImplicitNullChecks don't work (PPC64).")                         \
 947                                                                             \
 948   product(bool, EnableThreadSMRExtraValidityChecks, true, DIAGNOSTIC,       \
 949              "Enable Thread SMR extra validity checks")                     \
 950                                                                             \
 951   product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC,         \
 952              "Enable Thread SMR Statistics")                                \
 953                                                                             \
 954   product(bool, UseNotificationThread, true,                                \
 955           "Use Notification Thread")                                        \
 956                                                                             \
 957   product(bool, Inline, true,                                               \
 958           "Enable inlining")                                                \
 959                                                                             \
 960   product(bool, ClipInlining, true,                                         \
 961           "Clip inlining if aggregate method exceeds DesiredMethodLimit")   \
 962                                                                             \
 963   develop(bool, UseCHA, true,                                               \
 964           "Enable CHA")                                                     \
 965                                                                             \
 966   product(bool, UseVtableBasedCHA, true,  DIAGNOSTIC,                       \
 967           "Use vtable information during CHA")                              \
 968                                                                             \
 969   product(bool, UseTypeProfile, true,                                       \
 970           "Check interpreter profile for historically monomorphic calls")   \
 971                                                                             \
 972   product(bool, PrintInlining, false, DIAGNOSTIC,                           \
 973           "Print inlining optimizations")                                   \
 974                                                                             \
 975   product(bool, UsePopCountInstruction, false,                              \
 976           "Use population count instruction")                               \
 977                                                                             \
 978   develop(bool, EagerInitialization, false,                                 \
 979           "Eagerly initialize classes if possible")                         \
 980                                                                             \
 981   product(bool, LogTouchedMethods, false, DIAGNOSTIC,                       \
 982           "Log methods which have been ever touched in runtime")            \
 983                                                                             \
 984   product(bool, PrintTouchedMethodsAtExit, false, DIAGNOSTIC,               \
 985           "Print all methods that have been ever touched in runtime")       \
 986                                                                             \
 987   develop(bool, TraceMethodReplacement, false,                              \
 988           "Print when methods are replaced do to recompilation")            \
 989                                                                             \
 990   develop(bool, PrintMethodFlushing, false,                                 \
 991           "Print the nmethods being flushed")                               \
 992                                                                             \
 993   product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC,           \
 994           "print statistics about method flushing")                         \
 995                                                                             \
 996   product(intx, HotMethodDetectionLimit, 100000, DIAGNOSTIC,                \
 997           "Number of compiled code invocations after which "                \
 998           "the method is considered as hot by the flusher")                 \
 999           range(1, max_jint)                                                \
1000                                                                             \
1001   product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC,                       \
1002           "Minimum number of sweeper passes before an nmethod "             \
1003           "can be flushed")                                                 \
1004           range(0, max_intx)                                                \
1005                                                                             \
1006   product(bool, UseCodeAging, true,                                         \
1007           "Insert counter to detect warm methods")                          \
1008                                                                             \
1009   product(bool, StressCodeAging, false, DIAGNOSTIC,                         \
1010           "Start with counters compiled in")                                \
1011                                                                             \
1012   develop(bool, StressCodeBuffers, false,                                   \
1013           "Exercise code buffer expansion and other rare state changes")    \
1014                                                                             \
1015   product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC,                \
1016           "Generate extra debugging information for non-safepoints in "     \
1017           "nmethods")                                                       \
1018                                                                             \
1019   product(bool, PrintVMOptions, false,                                      \
1020           "Print flags that appeared on the command line")                  \
1021                                                                             \
1022   product(bool, IgnoreUnrecognizedVMOptions, false,                         \
1023           "Ignore unrecognized VM options")                                 \
1024                                                                             \
1025   product(bool, PrintCommandLineFlags, false,                               \
1026           "Print flags specified on command line or set by ergonomics")     \
1027                                                                             \
1028   product(bool, PrintFlagsInitial, false,                                   \
1029           "Print all VM flags before argument processing and exit VM")      \
1030                                                                             \
1031   product(bool, PrintFlagsFinal, false,                                     \
1032           "Print all VM flags after argument and ergonomic processing")     \
1033                                                                             \
1034   notproduct(bool, PrintFlagsWithComments, false,                           \
1035           "Print all VM flags with default values and descriptions and "    \
1036           "exit")                                                           \
1037                                                                             \
1038   product(bool, PrintFlagsRanges, false,                                    \
1039           "Print VM flags and their ranges")                                \
1040                                                                             \
1041   product(bool, SerializeVMOutput, true, DIAGNOSTIC,                        \
1042           "Use a mutex to serialize output to tty and LogFile")             \
1043                                                                             \
1044   product(bool, DisplayVMOutput, true, DIAGNOSTIC,                          \
1045           "Display all VM output on the tty, independently of LogVMOutput") \
1046                                                                             \
1047   product(bool, LogVMOutput, false, DIAGNOSTIC,                             \
1048           "Save VM output to LogFile")                                      \
1049                                                                             \
1050   product(ccstr, LogFile, NULL, DIAGNOSTIC,                                 \
1051           "If LogVMOutput or LogCompilation is on, save VM output to "      \
1052           "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1053                                                                             \
1054   product(ccstr, ErrorFile, NULL,                                           \
1055           "If an error occurs, save the error data to this file "           \
1056           "[default: ./hs_err_pid%p.log] (%p replaced with pid)")           \
1057                                                                             \
1058   product(bool, ExtensiveErrorReports,                                      \
1059           PRODUCT_ONLY(false) NOT_PRODUCT(true),                            \
1060           "Error reports are more extensive.")                              \
1061                                                                             \
1062   product(bool, DisplayVMOutputToStderr, false,                             \
1063           "If DisplayVMOutput is true, display all VM output to stderr")    \
1064                                                                             \
1065   product(bool, DisplayVMOutputToStdout, false,                             \
1066           "If DisplayVMOutput is true, display all VM output to stdout")    \
1067                                                                             \
1068   product(bool, ErrorFileToStderr, false,                                   \
1069           "If true, error data is printed to stderr instead of a file")     \
1070                                                                             \
1071   product(bool, ErrorFileToStdout, false,                                   \
1072           "If true, error data is printed to stdout instead of a file")     \
1073                                                                             \
1074   product(bool, UseHeavyMonitors, false,                                    \
1075           "use heavyweight instead of lightweight Java monitors")           \
1076                                                                             \
1077   product(bool, PrintStringTableStatistics, false,                          \
1078           "print statistics about the StringTable and SymbolTable")         \
1079                                                                             \
1080   product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC,                 \
1081           "verify StringTable contents at exit")                            \
1082                                                                             \
1083   notproduct(bool, PrintSymbolTableSizeHistogram, false,                    \
1084           "print histogram of the symbol table")                            \
1085                                                                             \
1086   product(ccstr, AbortVMOnException, NULL, DIAGNOSTIC,                      \
1087           "Call fatal if this exception is thrown.  Example: "              \
1088           "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1089                                                                             \
1090   product(ccstr, AbortVMOnExceptionMessage, NULL, DIAGNOSTIC,               \
1091           "Call fatal if the exception pointed by AbortVMOnException "      \
1092           "has this message")                                               \
1093                                                                             \
1094   develop(bool, DebugVtables, false,                                        \
1095           "add debugging code to vtable dispatch")                          \
1096                                                                             \
1097   notproduct(bool, PrintVtableStats, false,                                 \
1098           "print vtables stats at end of run")                              \
1099                                                                             \
1100   develop(bool, TraceCreateZombies, false,                                  \
1101           "trace creation of zombie nmethods")                              \
1102                                                                             \
1103   product(bool, RangeCheckElimination, true,                                \
1104           "Eliminate range checks")                                         \
1105                                                                             \
1106   develop_pd(bool, UncommonNullCast,                                        \
1107           "track occurrences of null in casts; adjust compiler tactics")    \
1108                                                                             \
1109   develop(bool, TypeProfileCasts,  true,                                    \
1110           "treat casts like calls for purposes of type profiling")          \
1111                                                                             \
1112   develop(bool, TraceLivenessGen, false,                                    \
1113           "Trace the generation of liveness analysis information")          \
1114                                                                             \
1115   notproduct(bool, TraceLivenessQuery, false,                               \
1116           "Trace queries of liveness analysis information")                 \
1117                                                                             \
1118   notproduct(bool, CollectIndexSetStatistics, false,                        \
1119           "Collect information about IndexSets")                            \
1120                                                                             \
1121   develop(intx, FastAllocateSizeLimit, 128*K,                               \
1122           /* Note:  This value is zero mod 1<<13 for a cheap sparc set. */  \
1123           "Inline allocations larger than this in doublewords must go slow")\
1124                                                                             \
1125   product_pd(bool, CompactStrings,                                          \
1126           "Enable Strings to use single byte chars in backing store")       \
1127                                                                             \
1128   product_pd(uintx, TypeProfileLevel,                                       \
1129           "=XYZ, with Z: Type profiling of arguments at call; "             \
1130                      "Y: Type profiling of return value at call; "          \
1131                      "X: Type profiling of parameters to methods; "         \
1132           "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods")             \
1133           constraint(TypeProfileLevelConstraintFunc, AfterErgo)             \
1134                                                                             \
1135   product(intx, TypeProfileArgsLimit,     2,                                \
1136           "max number of call arguments to consider for type profiling")    \
1137           range(0, 16)                                                      \
1138                                                                             \
1139   product(intx, TypeProfileParmsLimit,    2,                                \
1140           "max number of incoming parameters to consider for type profiling"\
1141           ", -1 for all")                                                   \
1142           range(-1, 64)                                                     \
1143                                                                             \
1144   /* statistics */                                                          \
1145   develop(bool, CountCompiledCalls, false,                                  \
1146           "Count method invocations")                                       \
1147                                                                             \
1148   notproduct(bool, ICMissHistogram, false,                                  \
1149           "Produce histogram of IC misses")                                 \
1150                                                                             \
1151   /* interpreter */                                                         \
1152   product_pd(bool, RewriteBytecodes,                                        \
1153           "Allow rewriting of bytecodes (bytecodes are not immutable)")     \
1154                                                                             \
1155   product_pd(bool, RewriteFrequentPairs,                                    \
1156           "Rewrite frequently used bytecode pairs into a single bytecode")  \
1157                                                                             \
1158   product(bool, PrintInterpreter, false, DIAGNOSTIC,                        \
1159           "Print the generated interpreter code")                           \
1160                                                                             \
1161   product(bool, UseInterpreter, true,                                       \
1162           "Use interpreter for non-compiled methods")                       \
1163                                                                             \
1164   develop(bool, UseFastSignatureHandlers, true,                             \
1165           "Use fast signature handlers for native calls")                   \
1166                                                                             \
1167   product(bool, UseLoopCounter, true,                                       \
1168           "Increment invocation counter on backward branch")                \
1169                                                                             \
1170   product_pd(bool, UseOnStackReplacement,                                   \
1171           "Use on stack replacement, calls runtime if invoc. counter "      \
1172           "overflows in loop")                                              \
1173                                                                             \
1174   notproduct(bool, TraceOnStackReplacement, false,                          \
1175           "Trace on stack replacement")                                     \
1176                                                                             \
1177   product_pd(bool, PreferInterpreterNativeStubs,                            \
1178           "Use always interpreter stubs for native methods invoked via "    \
1179           "interpreter")                                                    \
1180                                                                             \
1181   develop(bool, CountBytecodes, false,                                      \
1182           "Count number of bytecodes executed")                             \
1183                                                                             \
1184   develop(bool, PrintBytecodeHistogram, false,                              \
1185           "Print histogram of the executed bytecodes")                      \
1186                                                                             \
1187   develop(bool, PrintBytecodePairHistogram, false,                          \
1188           "Print histogram of the executed bytecode pairs")                 \
1189                                                                             \
1190   product(bool, PrintSignatureHandlers, false, DIAGNOSTIC,                  \
1191           "Print code generated for native method signature handlers")      \
1192                                                                             \
1193   develop(bool, VerifyOops, false,                                          \
1194           "Do plausibility checks for oops")                                \
1195                                                                             \
1196   develop(bool, CheckUnhandledOops, false,                                  \
1197           "Check for unhandled oops in VM code")                            \
1198                                                                             \
1199   develop(bool, VerifyJNIFields, trueInDebug,                               \
1200           "Verify jfieldIDs for instance fields")                           \
1201                                                                             \
1202   notproduct(bool, VerifyJNIEnvThread, false,                               \
1203           "Verify JNIEnv.thread == Thread::current() when entering VM "     \
1204           "from JNI")                                                       \
1205                                                                             \
1206   develop(bool, VerifyFPU, false,                                           \
1207           "Verify FPU state (check for NaN's, etc.)")                       \
1208                                                                             \
1209   develop(bool, VerifyThread, false,                                        \
1210           "Watch the thread register for corruption (SPARC only)")          \
1211                                                                             \
1212   develop(bool, VerifyActivationFrameSize, false,                           \
1213           "Verify that activation frame didn't become smaller than its "    \
1214           "minimal size")                                                   \
1215                                                                             \
1216   develop(bool, TraceFrequencyInlining, false,                              \
1217           "Trace frequency based inlining")                                 \
1218                                                                             \
1219   develop_pd(bool, InlineIntrinsics,                                        \
1220           "Inline intrinsics that can be statically resolved")              \
1221                                                                             \
1222   product_pd(bool, ProfileInterpreter,                                      \
1223           "Profile at the bytecode level during interpretation")            \
1224                                                                             \
1225   develop_pd(bool, ProfileTraps,                                            \
1226           "Profile deoptimization traps at the bytecode level")             \
1227                                                                             \
1228   product(intx, ProfileMaturityPercentage, 20,                              \
1229           "number of method invocations/branches (expressed as % of "       \
1230           "CompileThreshold) before using the method's profile")            \
1231           range(0, 100)                                                     \
1232                                                                             \
1233   product(bool, PrintMethodData, false, DIAGNOSTIC,                         \
1234           "Print the results of +ProfileInterpreter at end of run")         \
1235                                                                             \
1236   develop(bool, VerifyDataPointer, trueInDebug,                             \
1237           "Verify the method data pointer during interpreter profiling")    \
1238                                                                             \
1239   notproduct(bool, CrashGCForDumpingJavaThread, false,                      \
1240           "Manually make GC thread crash then dump java stack trace;  "     \
1241           "Test only")                                                      \
1242                                                                             \
1243   /* compilation */                                                         \
1244   product(bool, UseCompiler, true,                                          \
1245           "Use Just-In-Time compilation")                                   \
1246                                                                             \
1247   product(bool, UseCounterDecay, true,                                      \
1248           "Adjust recompilation counters")                                  \
1249                                                                             \
1250   develop(intx, CounterHalfLifeTime,    30,                                 \
1251           "Half-life time of invocation counters (in seconds)")             \
1252                                                                             \
1253   develop(intx, CounterDecayMinIntervalLength,   500,                       \
1254           "The minimum interval (in milliseconds) between invocation of "   \
1255           "CounterDecay")                                                   \
1256                                                                             \
1257   product(bool, AlwaysCompileLoopMethods, false,                            \
1258           "When using recompilation, never interpret methods "              \
1259           "containing loops")                                               \
1260                                                                             \
1261   product(intx,  AllocatePrefetchStyle, 1,                                  \
1262           "0 = no prefetch, "                                               \
1263           "1 = generate prefetch instructions for each allocation, "        \
1264           "2 = use TLAB watermark to gate allocation prefetch, "            \
1265           "3 = generate one prefetch instruction per cache line")           \
1266           range(0, 3)                                                       \
1267                                                                             \
1268   product(intx,  AllocatePrefetchDistance, -1,                              \
1269           "Distance to prefetch ahead of allocation pointer. "              \
1270           "-1: use system-specific value (automatically determined")        \
1271           constraint(AllocatePrefetchDistanceConstraintFunc,AfterMemoryInit)\
1272                                                                             \
1273   product(intx,  AllocatePrefetchLines, 3,                                  \
1274           "Number of lines to prefetch ahead of array allocation pointer")  \
1275           range(1, 64)                                                      \
1276                                                                             \
1277   product(intx,  AllocateInstancePrefetchLines, 1,                          \
1278           "Number of lines to prefetch ahead of instance allocation "       \
1279           "pointer")                                                        \
1280           range(1, 64)                                                      \
1281                                                                             \
1282   product(intx,  AllocatePrefetchStepSize, 16,                              \
1283           "Step size in bytes of sequential prefetch instructions")         \
1284           range(1, 512)                                                     \
1285           constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1286                                                                             \
1287   product(intx,  AllocatePrefetchInstr, 0,                                  \
1288           "Select instruction to prefetch ahead of allocation pointer")     \
1289           constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit)  \
1290                                                                             \
1291   /* deoptimization */                                                      \
1292   develop(bool, TraceDeoptimization, false,                                 \
1293           "Trace deoptimization")                                           \
1294                                                                             \
1295   develop(bool, PrintDeoptimizationDetails, false,                          \
1296           "Print more information about deoptimization")                    \
1297                                                                             \
1298   develop(bool, DebugDeoptimization, false,                                 \
1299           "Tracing various information while debugging deoptimization")     \
1300                                                                             \
1301   product(intx, SelfDestructTimer, 0,                                       \
1302           "Will cause VM to terminate after a given time (in minutes) "     \
1303           "(0 means off)")                                                  \
1304           range(0, max_intx)                                                \
1305                                                                             \
1306   product(intx, MaxJavaStackTraceDepth, 1024,                               \
1307           "The maximum number of lines in the stack trace for Java "        \
1308           "exceptions (0 means all)")                                       \
1309           range(0, max_jint/2)                                              \
1310                                                                             \
1311   /* notice: the max range value here is max_jint, not max_intx  */         \
1312   /* because of overflow issue                                   */         \
1313   product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC,              \
1314           "Guarantee a safepoint (at least) every so many milliseconds "    \
1315           "(0 means none)")                                                 \
1316           range(0, max_jint)                                                \
1317                                                                             \
1318   product(intx, SafepointTimeoutDelay, 10000,                               \
1319           "Delay in milliseconds for option SafepointTimeout")              \
1320           range(0, max_intx LP64_ONLY(/MICROUNITS))                         \
1321                                                                             \
1322   product(intx, NmethodSweepActivity, 10,                                   \
1323           "Removes cold nmethods from code cache if > 0. Higher values "    \
1324           "result in more aggressive sweeping")                             \
1325           range(0, 2000)                                                    \
1326                                                                             \
1327   notproduct(bool, LogSweeper, false,                                       \
1328           "Keep a ring buffer of sweeper activity")                         \
1329                                                                             \
1330   notproduct(intx, SweeperLogEntries, 1024,                                 \
1331           "Number of records in the ring buffer of sweeper activity")       \
1332                                                                             \
1333   develop(intx, MallocCatchPtr, -1,                                         \
1334           "Hit breakpoint when mallocing/freeing this pointer")             \
1335                                                                             \
1336   notproduct(ccstrlist, SuppressErrorAt, "",                                \
1337           "List of assertions (file:line) to muzzle")                       \
1338                                                                             \
1339   develop(intx, StackPrintLimit, 100,                                       \
1340           "number of stack frames to print in VM-level stack dump")         \
1341                                                                             \
1342   product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC,                       \
1343           "max number of compiled code units to print in error log")        \
1344           range(0, VMError::max_error_log_print_code)                       \
1345                                                                             \
1346   notproduct(intx, MaxElementPrintSize, 256,                                \
1347           "maximum number of elements to print")                            \
1348                                                                             \
1349   notproduct(intx, MaxSubklassPrintSize, 4,                                 \
1350           "maximum number of subklasses to print when printing klass")      \
1351                                                                             \
1352   develop(intx, MaxForceInlineLevel, 100,                                   \
1353           "maximum number of nested calls that are forced for inlining "    \
1354           "(using CompileCommand or marked w/ @ForceInline)")               \
1355           range(0, max_jint)                                                \
1356                                                                             \
1357   product(intx, MinInliningThreshold, 250,                                  \
1358           "The minimum invocation count a method needs to have to be "      \
1359           "inlined")                                                        \
1360           range(0, max_jint)                                                \
1361                                                                             \
1362   develop(intx, MethodHistogramCutoff, 100,                                 \
1363           "The cutoff value for method invocation histogram (+CountCalls)") \
1364                                                                             \
1365   develop(intx, DontYieldALotInterval,    10,                               \
1366           "Interval between which yields will be dropped (milliseconds)")   \
1367                                                                             \
1368   notproduct(intx, DeoptimizeALotInterval,     5,                           \
1369           "Number of exits until DeoptimizeALot kicks in")                  \
1370                                                                             \
1371   notproduct(intx, ZombieALotInterval,     5,                               \
1372           "Number of exits until ZombieALot kicks in")                      \
1373                                                                             \
1374   product(uintx, MallocMaxTestWords,     0, DIAGNOSTIC,                     \
1375           "If non-zero, maximum number of words that malloc/realloc can "   \
1376           "allocate (for testing only)")                                    \
1377           range(0, max_uintx)                                               \
1378                                                                             \
1379   product(intx, TypeProfileWidth, 2,                                        \
1380           "Number of receiver types to record in call/cast profile")        \
1381           range(0, 8)                                                       \
1382                                                                             \
1383   develop(intx, BciProfileWidth,      2,                                    \
1384           "Number of return bci's to record in ret profile")                \
1385                                                                             \
1386   product(intx, PerMethodRecompilationCutoff, 400,                          \
1387           "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1388           range(-1, max_intx)                                               \
1389                                                                             \
1390   product(intx, PerBytecodeRecompilationCutoff, 200,                        \
1391           "Per-BCI limit on repeated recompilation (-1=>'Inf')")            \
1392           range(-1, max_intx)                                               \
1393                                                                             \
1394   product(intx, PerMethodTrapLimit,  100,                                   \
1395           "Limit on traps (of one kind) in a method (includes inlines)")    \
1396           range(0, max_jint)                                                \
1397                                                                             \
1398   product(intx, PerMethodSpecTrapLimit,  5000, EXPERIMENTAL,                \
1399           "Limit on speculative traps (of one kind) in a method "           \
1400           "(includes inlines)")                                             \
1401           range(0, max_jint)                                                \
1402                                                                             \
1403   product(intx, PerBytecodeTrapLimit,  4,                                   \
1404           "Limit on traps (of one kind) at a particular BCI")               \
1405           range(0, max_jint)                                                \
1406                                                                             \
1407   product(intx, SpecTrapLimitExtraEntries,  3, EXPERIMENTAL,                \
1408           "Extra method data trap entries for speculation")                 \
1409                                                                             \
1410   product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC,                   \
1411           "Ratio of call site execution to caller method invocation")       \
1412                                                                             \
1413   develop(intx, InlineThrowCount,    50,                                    \
1414           "Force inlining of interpreted methods that throw this often")    \
1415           range(0, max_jint)                                                \
1416                                                                             \
1417   develop(intx, InlineThrowMaxSize,   200,                                  \
1418           "Force inlining of throwing methods smaller than this")           \
1419           range(0, max_jint)                                                \
1420                                                                             \
1421   product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M),        \
1422           "Initial threshold (in bytes) at which a garbage collection "     \
1423           "is done to reduce Metaspace usage")                              \
1424           constraint(MetaspaceSizeConstraintFunc,AfterErgo)                 \
1425                                                                             \
1426   product(size_t, MaxMetaspaceSize, max_uintx,                              \
1427           "Maximum size of Metaspaces (in bytes)")                          \
1428           constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo)              \
1429                                                                             \
1430   product(size_t, CompressedClassSpaceSize, 1*G,                            \
1431           "Maximum size of class area in Metaspace when compressed "        \
1432           "class pointers are used")                                        \
1433           range(1*M, 3*G)                                                   \
1434                                                                             \
1435   develop(size_t, CompressedClassSpaceBaseAddress, 0,                       \
1436           "Force the class space to be allocated at this address or "       \
1437           "fails VM initialization (requires -Xshare=off.")                 \
1438                                                                             \
1439   product(ccstr, MetaspaceReclaimPolicy, "balanced",                        \
1440           "options: balanced, aggressive, none")                            \
1441                                                                             \
1442   product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC,          \
1443           "Print metaspace statistics upon VM exit.")                       \
1444                                                                             \
1445   develop(bool, MetaspaceGuardAllocations, false,                           \
1446           "Metapace allocations are guarded.")                              \
1447                                                                             \
1448   develop(bool, MetaspaceHandleDeallocations, true,                         \
1449           "Switch off Metapace deallocation handling.")                     \
1450                                                                             \
1451   product(uintx, MinHeapFreeRatio, 40, MANAGEABLE,                          \
1452           "The minimum percentage of heap free after GC to avoid expansion."\
1453           " For most GCs this applies to the old generation. In G1 and"     \
1454           " ParallelGC it applies to the whole heap.")                      \
1455           range(0, 100)                                                     \
1456           constraint(MinHeapFreeRatioConstraintFunc,AfterErgo)              \
1457                                                                             \
1458   product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE,                          \
1459           "The maximum percentage of heap free after GC to avoid shrinking."\
1460           " For most GCs this applies to the old generation. In G1 and"     \
1461           " ParallelGC it applies to the whole heap.")                      \
1462           range(0, 100)                                                     \
1463           constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo)              \
1464                                                                             \
1465   product(bool, ShrinkHeapInSteps, true,                                    \
1466           "When disabled, informs the GC to shrink the java heap directly"  \
1467           " to the target size at the next full GC rather than requiring"   \
1468           " smaller steps during multiple full GCs.")                       \
1469                                                                             \
1470   product(intx, SoftRefLRUPolicyMSPerMB, 1000,                              \
1471           "Number of milliseconds per MB of free space in the heap")        \
1472           range(0, max_intx)                                                \
1473           constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1474                                                                             \
1475   product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K),               \
1476           "The minimum change in heap space due to GC (in bytes)")          \
1477           range(0, max_uintx)                                               \
1478                                                                             \
1479   product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K),           \
1480           "The minimum expansion of Metaspace (in bytes)")                  \
1481           range(0, max_uintx)                                               \
1482                                                                             \
1483   product(uintx, MaxMetaspaceFreeRatio,    70,                              \
1484           "The maximum percentage of Metaspace free after GC to avoid "     \
1485           "shrinking")                                                      \
1486           range(0, 100)                                                     \
1487           constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo)         \
1488                                                                             \
1489   product(uintx, MinMetaspaceFreeRatio,    40,                              \
1490           "The minimum percentage of Metaspace free after GC to avoid "     \
1491           "expansion")                                                      \
1492           range(0, 99)                                                      \
1493           constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo)         \
1494                                                                             \
1495   product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M),             \
1496           "The maximum expansion of Metaspace without full GC (in bytes)")  \
1497           range(0, max_uintx)                                               \
1498                                                                             \
1499   /* stack parameters */                                                    \
1500   product_pd(intx, StackYellowPages,                                        \
1501           "Number of yellow zone (recoverable overflows) pages of size "    \
1502           "4KB. If pages are bigger yellow zone is aligned up.")            \
1503           range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5))     \
1504                                                                             \
1505   product_pd(intx, StackRedPages,                                           \
1506           "Number of red zone (unrecoverable overflows) pages of size "     \
1507           "4KB. If pages are bigger red zone is aligned up.")               \
1508           range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2))           \
1509                                                                             \
1510   product_pd(intx, StackReservedPages,                                      \
1511           "Number of reserved zone (reserved to annotated methods) pages"   \
1512           " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1513           range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1514                                                                             \
1515   product(bool, RestrictReservedStack, true,                                \
1516           "Restrict @ReservedStackAccess to trusted classes")               \
1517                                                                             \
1518   /* greater stack shadow pages can't generate instruction to bang stack */ \
1519   product_pd(intx, StackShadowPages,                                        \
1520           "Number of shadow zone (for overflow checking) pages of size "    \
1521           "4KB. If pages are bigger shadow zone is aligned up. "            \
1522           "This should exceed the depth of the VM and native call stack.")  \
1523           range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30))    \
1524                                                                             \
1525   product_pd(intx, ThreadStackSize,                                         \
1526           "Thread Stack Size (in Kbytes)")                                  \
1527           range(0, 1 * M)                                                   \
1528                                                                             \
1529   product_pd(intx, VMThreadStackSize,                                       \
1530           "Non-Java Thread Stack Size (in Kbytes)")                         \
1531           range(0, max_intx/(1 * K))                                        \
1532                                                                             \
1533   product_pd(intx, CompilerThreadStackSize,                                 \
1534           "Compiler Thread Stack Size (in Kbytes)")                         \
1535           range(0, max_intx/(1 * K))                                        \
1536                                                                             \
1537   develop_pd(size_t, JVMInvokeMethodSlack,                                  \
1538           "Stack space (bytes) required for JVM_InvokeMethod to complete")  \
1539                                                                             \
1540   /* code cache parameters                                    */            \
1541   develop_pd(uintx, CodeCacheSegmentSize,                                   \
1542           "Code cache segment size (in bytes) - smallest unit of "          \
1543           "allocation")                                                     \
1544           range(1, 1024)                                                    \
1545           constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo)         \
1546                                                                             \
1547   develop_pd(intx, CodeEntryAlignment,                                      \
1548           "Code entry alignment for generated code (in bytes)")             \
1549           constraint(CodeEntryAlignmentConstraintFunc, AfterErgo)           \
1550                                                                             \
1551   product_pd(intx, OptoLoopAlignment,                                       \
1552           "Align inner loops to zero relative to this modulus")             \
1553           range(1, 16)                                                      \
1554           constraint(OptoLoopAlignmentConstraintFunc, AfterErgo)            \
1555                                                                             \
1556   product_pd(uintx, InitialCodeCacheSize,                                   \
1557           "Initial code cache size (in bytes)")                             \
1558           constraint(VMPageSizeConstraintFunc, AtParse)                     \
1559                                                                             \
1560   develop_pd(uintx, CodeCacheMinimumUseSpace,                               \
1561           "Minimum code cache size (in bytes) required to start VM.")       \
1562           range(0, max_uintx)                                               \
1563                                                                             \
1564   product(bool, SegmentedCodeCache, false,                                  \
1565           "Use a segmented code cache")                                     \
1566                                                                             \
1567   product_pd(uintx, ReservedCodeCacheSize,                                  \
1568           "Reserved code cache size (in bytes) - maximum code cache size")  \
1569           constraint(VMPageSizeConstraintFunc, AtParse)                     \
1570                                                                             \
1571   product_pd(uintx, NonProfiledCodeHeapSize,                                \
1572           "Size of code heap with non-profiled methods (in bytes)")         \
1573           range(0, max_uintx)                                               \
1574                                                                             \
1575   product_pd(uintx, ProfiledCodeHeapSize,                                   \
1576           "Size of code heap with profiled methods (in bytes)")             \
1577           range(0, max_uintx)                                               \
1578                                                                             \
1579   product_pd(uintx, NonNMethodCodeHeapSize,                                 \
1580           "Size of code heap with non-nmethods (in bytes)")                 \
1581           constraint(VMPageSizeConstraintFunc, AtParse)                     \
1582                                                                             \
1583   product_pd(uintx, CodeCacheExpansionSize,                                 \
1584           "Code cache expansion size (in bytes)")                           \
1585           range(32*K, max_uintx)                                            \
1586                                                                             \
1587   product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC,                    \
1588           "Minimum number of segments in a code cache block")               \
1589           range(1, 100)                                                     \
1590                                                                             \
1591   notproduct(bool, ExitOnFullCodeCache, false,                              \
1592           "Exit the VM if we fill the code cache")                          \
1593                                                                             \
1594   product(bool, UseCodeCacheFlushing, true,                                 \
1595           "Remove cold/old nmethods from the code cache")                   \
1596                                                                             \
1597   product(double, SweeperThreshold, 0.5,                                    \
1598           "Threshold controlling when code cache sweeper is invoked."       \
1599           "Value is percentage of ReservedCodeCacheSize.")                  \
1600           range(0.0, 100.0)                                                 \
1601                                                                             \
1602   product(uintx, StartAggressiveSweepingAt, 10,                             \
1603           "Start aggressive sweeping if X[%] of the code cache is free."    \
1604           "Segmented code cache: X[%] of the non-profiled heap."            \
1605           "Non-segmented code cache: X[%] of the total code cache")         \
1606           range(0, 100)                                                     \
1607                                                                             \
1608   /* interpreter debugging */                                               \
1609   develop(intx, BinarySwitchThreshold, 5,                                   \
1610           "Minimal number of lookupswitch entries for rewriting to binary " \
1611           "switch")                                                         \
1612                                                                             \
1613   develop(intx, StopInterpreterAt, 0,                                       \
1614           "Stop interpreter execution at specified bytecode number")        \
1615                                                                             \
1616   develop(intx, TraceBytecodesAt, 0,                                        \
1617           "Trace bytecodes starting with specified bytecode number")        \
1618                                                                             \
1619   /* Priorities */                                                          \
1620   product_pd(bool, UseThreadPriorities,  "Use native thread priorities")    \
1621                                                                             \
1622   product(intx, ThreadPriorityPolicy, 0,                                    \
1623           "0 : Normal.                                                     "\
1624           "    VM chooses priorities that are appropriate for normal       "\
1625           "    applications.                                               "\
1626           "    On Windows applications are allowed to use higher native    "\
1627           "    priorities. However, with ThreadPriorityPolicy=0, VM will   "\
1628           "    not use the highest possible native priority,               "\
1629           "    THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with     "\
1630           "    system threads. On Linux thread priorities are ignored      "\
1631           "    because the OS does not support static priority in          "\
1632           "    SCHED_OTHER scheduling class which is the only choice for   "\
1633           "    non-root, non-realtime applications.                        "\
1634           "1 : Aggressive.                                                 "\
1635           "    Java thread priorities map over to the entire range of      "\
1636           "    native thread priorities. Higher Java thread priorities map "\
1637           "    to higher native thread priorities. This policy should be   "\
1638           "    used with care, as sometimes it can cause performance       "\
1639           "    degradation in the application and/or the entire system. On "\
1640           "    Linux/BSD/macOS this policy requires root privilege or an   "\
1641           "    extended capability.")                                       \
1642           range(0, 1)                                                       \
1643                                                                             \
1644   product(bool, ThreadPriorityVerbose, false,                               \
1645           "Print priority changes")                                         \
1646                                                                             \
1647   product(intx, CompilerThreadPriority, -1,                                 \
1648           "The native priority at which compiler threads should run "       \
1649           "(-1 means no change)")                                           \
1650           range(min_jint, max_jint)                                         \
1651                                                                             \
1652   product(intx, VMThreadPriority, -1,                                       \
1653           "The native priority at which the VM thread should run "          \
1654           "(-1 means no change)")                                           \
1655           range(-1, 127)                                                    \
1656                                                                             \
1657   product(intx, JavaPriority1_To_OSPriority, -1,                            \
1658           "Map Java priorities to OS priorities")                           \
1659           range(-1, 127)                                                    \
1660                                                                             \
1661   product(intx, JavaPriority2_To_OSPriority, -1,                            \
1662           "Map Java priorities to OS priorities")                           \
1663           range(-1, 127)                                                    \
1664                                                                             \
1665   product(intx, JavaPriority3_To_OSPriority, -1,                            \
1666           "Map Java priorities to OS priorities")                           \
1667           range(-1, 127)                                                    \
1668                                                                             \
1669   product(intx, JavaPriority4_To_OSPriority, -1,                            \
1670           "Map Java priorities to OS priorities")                           \
1671           range(-1, 127)                                                    \
1672                                                                             \
1673   product(intx, JavaPriority5_To_OSPriority, -1,                            \
1674           "Map Java priorities to OS priorities")                           \
1675           range(-1, 127)                                                    \
1676                                                                             \
1677   product(intx, JavaPriority6_To_OSPriority, -1,                            \
1678           "Map Java priorities to OS priorities")                           \
1679           range(-1, 127)                                                    \
1680                                                                             \
1681   product(intx, JavaPriority7_To_OSPriority, -1,                            \
1682           "Map Java priorities to OS priorities")                           \
1683           range(-1, 127)                                                    \
1684                                                                             \
1685   product(intx, JavaPriority8_To_OSPriority, -1,                            \
1686           "Map Java priorities to OS priorities")                           \
1687           range(-1, 127)                                                    \
1688                                                                             \
1689   product(intx, JavaPriority9_To_OSPriority, -1,                            \
1690           "Map Java priorities to OS priorities")                           \
1691           range(-1, 127)                                                    \
1692                                                                             \
1693   product(intx, JavaPriority10_To_OSPriority,-1,                            \
1694           "Map Java priorities to OS priorities")                           \
1695           range(-1, 127)                                                    \
1696                                                                             \
1697   product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL,         \
1698           "Java thread priority 10 maps to critical scheduling priority")   \
1699                                                                             \
1700   product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL,     \
1701           "Compiler thread(s) run at critical scheduling priority")         \
1702                                                                             \
1703   develop(intx, NewCodeParameter,      0,                                   \
1704           "Testing Only: Create a dedicated integer parameter before "      \
1705           "putback")                                                        \
1706                                                                             \
1707   /* new oopmap storage allocation */                                       \
1708   develop(intx, MinOopMapAllocation,     8,                                 \
1709           "Minimum number of OopMap entries in an OopMapSet")               \
1710                                                                             \
1711   /* recompilation */                                                       \
1712   product_pd(intx, CompileThreshold,                                        \
1713           "number of interpreted method invocations before (re-)compiling") \
1714           constraint(CompileThresholdConstraintFunc, AfterErgo)             \
1715                                                                             \
1716   product_pd(bool, TieredCompilation,                                       \
1717           "Enable tiered compilation")                                      \
1718                                                                             \
1719   /* Properties for Java libraries  */                                      \
1720                                                                             \
1721   product(uint64_t, MaxDirectMemorySize, 0,                                 \
1722           "Maximum total size of NIO direct-buffer allocations")            \
1723           range(0, max_jlong)                                               \
1724                                                                             \
1725   /* Flags used for temporary code during development  */                   \
1726                                                                             \
1727   product(bool, UseNewCode, false, DIAGNOSTIC,                              \
1728           "Testing Only: Use the new version while testing")                \
1729                                                                             \
1730   product(bool, UseNewCode2, false, DIAGNOSTIC,                             \
1731           "Testing Only: Use the new version while testing")                \
1732                                                                             \
1733   product(bool, UseNewCode3, false, DIAGNOSTIC,                             \
1734           "Testing Only: Use the new version while testing")                \
1735                                                                             \
1736   product(intx, ContPerfTest, 1000, DIAGNOSTIC,                             \
1737           "Testing Only: Use the new version while testing")                \
1738                                                                             \
1739   notproduct(bool, UseDebuggerErgo, false,                                  \
1740           "Debugging Only: Adjust the VM to be more debugger-friendly. "    \
1741           "Turns on the other UseDebuggerErgo* flags")                      \
1742                                                                             \
1743   notproduct(bool, UseDebuggerErgo1, false,                                 \
1744           "Debugging Only: Enable workarounds for debugger induced "        \
1745           "os::processor_id() >= os::processor_count() problems")           \
1746                                                                             \
1747   notproduct(bool, UseDebuggerErgo2, false,                                 \
1748           "Debugging Only: Limit the number of spawned JVM threads")        \
1749                                                                             \
1750   notproduct(bool, EnableJVMTIStackDepthAsserts, true,                      \
1751           "Enable JVMTI asserts related to stack depth checks")             \
1752                                                                             \
1753   /* flags for performance data collection */                               \
1754                                                                             \
1755   product(bool, UsePerfData, true,                                          \
1756           "Flag to disable jvmstat instrumentation for performance testing "\
1757           "and problem isolation purposes")                                 \
1758                                                                             \
1759   product(bool, PerfDataSaveToFile, false,                                  \
1760           "Save PerfData memory to hsperfdata_<pid> file on exit")          \
1761                                                                             \
1762   product(ccstr, PerfDataSaveFile, NULL,                                    \
1763           "Save PerfData memory to the specified absolute pathname. "       \
1764           "The string %p in the file name (if present) "                    \
1765           "will be replaced by pid")                                        \
1766                                                                             \
1767   product(intx, PerfDataSamplingInterval, 50,                               \
1768           "Data sampling interval (in milliseconds)")                       \
1769           range(PeriodicTask::min_interval, max_jint)                       \
1770           constraint(PerfDataSamplingIntervalFunc, AfterErgo)               \
1771                                                                             \
1772   product(bool, PerfDisableSharedMem, false,                                \
1773           "Store performance data in standard memory")                      \
1774                                                                             \
1775   product(intx, PerfDataMemorySize, 32*K,                                   \
1776           "Size of performance data memory region. Will be rounded "        \
1777           "up to a multiple of the native os page size.")                   \
1778           range(128, 32*64*K)                                               \
1779                                                                             \
1780   product(intx, PerfMaxStringConstLength, 1024,                             \
1781           "Maximum PerfStringConstant string length before truncation")     \
1782           range(32, 32*K)                                                   \
1783                                                                             \
1784   product(bool, PerfAllowAtExitRegistration, false,                         \
1785           "Allow registration of atexit() methods")                         \
1786                                                                             \
1787   product(bool, PerfBypassFileSystemCheck, false,                           \
1788           "Bypass Win32 file system criteria checks (Windows Only)")        \
1789                                                                             \
1790   product(intx, UnguardOnExecutionViolation, 0,                             \
1791           "Unguard page and retry on no-execute fault (Win32 only) "        \
1792           "0=off, 1=conservative, 2=aggressive")                            \
1793           range(0, 2)                                                       \
1794                                                                             \
1795   /* Serviceability Support */                                              \
1796                                                                             \
1797   product(bool, ManagementServer, false,                                    \
1798           "Create JMX Management Server")                                   \
1799                                                                             \
1800   product(bool, DisableAttachMechanism, false,                              \
1801           "Disable mechanism that allows tools to attach to this VM")       \
1802                                                                             \
1803   product(bool, StartAttachListener, false,                                 \
1804           "Always start Attach Listener at VM startup")                     \
1805                                                                             \
1806   product(bool, EnableDynamicAgentLoading, true,                            \
1807           "Allow tools to load agents with the attach mechanism")           \
1808                                                                             \
1809   product(bool, PrintConcurrentLocks, false, MANAGEABLE,                    \
1810           "Print java.util.concurrent locks in thread dump")                \
1811                                                                             \
1812   /* Shared spaces */                                                       \
1813                                                                             \
1814   product(bool, UseSharedSpaces, true,                                      \
1815           "Use shared spaces for metadata")                                 \
1816                                                                             \
1817   product(bool, VerifySharedSpaces, false,                                  \
1818           "Verify integrity of shared spaces")                              \
1819                                                                             \
1820   product(bool, RequireSharedSpaces, false,                                 \
1821           "Require shared spaces for metadata")                             \
1822                                                                             \
1823   product(bool, DumpSharedSpaces, false,                                    \
1824           "Special mode: JVM reads a class list, loads classes, builds "    \
1825           "shared spaces, and dumps the shared spaces to a file to be "     \
1826           "used in future JVM runs")                                        \
1827                                                                             \
1828   product(bool, DynamicDumpSharedSpaces, false,                             \
1829           "Dynamic archive")                                                \
1830                                                                             \
1831   product(bool, RecordDynamicDumpInfo, false,                               \
1832           "Record class info for jcmd VM.cds dynamic_dump")                 \
1833                                                                             \
1834   product(bool, PrintSharedArchiveAndExit, false,                           \
1835           "Print shared archive file contents")                             \
1836                                                                             \
1837   product(bool, PrintSharedDictionary, false,                               \
1838           "If PrintSharedArchiveAndExit is true, also print the shared "    \
1839           "dictionary")                                                     \
1840                                                                             \
1841   product(size_t, SharedBaseAddress, LP64_ONLY(32*G)                        \
1842           NOT_LP64(LINUX_ONLY(2*G) NOT_LINUX(0)),                           \
1843           "Address to allocate shared memory region for class data")        \
1844           range(0, SIZE_MAX)                                                \
1845                                                                             \
1846   product(ccstr, SharedArchiveConfigFile, NULL,                             \
1847           "Data to add to the CDS archive file")                            \
1848                                                                             \
1849   product(uintx, SharedSymbolTableBucketSize, 4,                            \
1850           "Average number of symbols per bucket in shared table")           \
1851           range(2, 246)                                                     \
1852                                                                             \
1853   product(bool, AllowArchivingWithJavaAgent, false, DIAGNOSTIC,             \
1854           "Allow Java agent to be run with CDS dumping")                    \
1855                                                                             \
1856   product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC,                  \
1857           "Print generated stub code for method handles")                   \
1858                                                                             \
1859   product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC,               \
1860           "perform extra checks when constructing method handles")          \
1861                                                                             \
1862   product(bool, ShowHiddenFrames, false, DIAGNOSTIC,                        \
1863           "show method handle implementation frames (usually hidden)")      \
1864                                                                             \
1865   product(bool, ShowCarrierFrames, false, DIAGNOSTIC,                       \
1866           "show virtual threads' carrier frames in exceptions")             \
1867                                                                             \
1868   product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL,             \
1869           "trust final non-static declarations for constant folding")       \
1870                                                                             \
1871   product(bool, FoldStableValues, true, DIAGNOSTIC,                         \
1872           "Optimize loads from stable fields (marked w/ @Stable)")          \
1873                                                                             \
1874   product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC,                         \
1875           "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1876           "resolved before the bootstrap method is called; 1: when a BSM "  \
1877           "that may accept a BootstrapCallInfo is detected, use that API "  \
1878           "to pass BSM arguments, which allows the BSM to delay their "     \
1879           "resolution; 2+: stress test the BCI API by calling more BSMs "   \
1880           "via that API, instead of with the eagerly-resolved array.")      \
1881                                                                             \
1882   product(bool, PauseAtStartup,      false, DIAGNOSTIC,                     \
1883           "Causes the VM to pause at startup time and wait for the pause "  \
1884           "file to be removed (default: ./vm.paused.<pid>)")                \
1885                                                                             \
1886   product(ccstr, PauseAtStartupFile, NULL, DIAGNOSTIC,                      \
1887           "The file to create and for whose removal to await when pausing " \
1888           "at startup. (default: ./vm.paused.<pid>)")                       \
1889                                                                             \
1890   product(bool, PauseAtExit, false, DIAGNOSTIC,                             \
1891           "Pause and wait for keypress on exit if a debugger is attached")  \
1892                                                                             \
1893   product(bool, ExtendedDTraceProbes,    false,                             \
1894           "Enable performance-impacting dtrace probes")                     \
1895                                                                             \
1896   product(bool, DTraceMethodProbes, false,                                  \
1897           "Enable dtrace probes for method-entry and method-exit")          \
1898                                                                             \
1899   product(bool, DTraceAllocProbes, false,                                   \
1900           "Enable dtrace probes for object allocation")                     \
1901                                                                             \
1902   product(bool, DTraceMonitorProbes, false,                                 \
1903           "Enable dtrace probes for monitor events")                        \
1904                                                                             \
1905   product(bool, RelaxAccessControlCheck, false,                             \
1906           "Relax the access control checks in the verifier")                \
1907                                                                             \
1908   product(uintx, StringTableSize, defaultStringTableSize,                   \
1909           "Number of buckets in the interned String table "                 \
1910           "(will be rounded to nearest higher power of 2)")                 \
1911           range(minimumStringTableSize, 16777216ul /* 2^24 */)              \
1912                                                                             \
1913   product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL,     \
1914           "Number of buckets in the JVM internal Symbol table")             \
1915           range(minimumSymbolTableSize, 16777216ul /* 2^24 */)              \
1916                                                                             \
1917   product(bool, UseStringDeduplication, false,                              \
1918           "Use string deduplication")                                       \
1919                                                                             \
1920   product(uint, StringDeduplicationAgeThreshold, 3,                         \
1921           "A string must reach this age (or be promoted to an old region) " \
1922           "to be considered for deduplication")                             \
1923           range(1, markWord::max_age)                                       \
1924                                                                             \
1925   product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL,   \
1926           "Approximate initial number of buckets in the table")             \
1927           range(1, 1 * G)                                                   \
1928                                                                             \
1929   product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL,     \
1930           "Entries per bucket above which the table should be expanded")    \
1931           range(0.1, 1000.0)                                                \
1932                                                                             \
1933   product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL,    \
1934           "Entries per bucket below which the table should be shrunk")      \
1935           range(0.01, 100.0)                                                \
1936                                                                             \
1937   product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL,    \
1938           "Desired entries per bucket when resizing the table")             \
1939           range(0.01, 1000.0)                                               \
1940                                                                             \
1941   product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1942           "Minimum number of dead table entries for cleaning the table")    \
1943                                                                             \
1944   product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL,      \
1945           "Minimum percentage of dead table entries for cleaning the table") \
1946           range(1, 100)                                                     \
1947                                                                             \
1948   product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC,           \
1949           "Force more frequent table resizing")                             \
1950                                                                             \
1951   product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC,             \
1952           "Seed for the table hashing function; 0 requests computed seed")  \
1953                                                                             \
1954   product(bool, WhiteBoxAPI, false, DIAGNOSTIC,                             \
1955           "Enable internal testing APIs")                                   \
1956                                                                             \
1957   product(ccstr, DumpLoadedClassList, NULL,                                 \
1958           "Dump the names all loaded classes, that could be stored into "   \
1959           "the CDS archive, in the specified file")                         \
1960                                                                             \
1961   product(ccstr, SharedClassListFile, NULL,                                 \
1962           "Override the default CDS class list")                            \
1963                                                                             \
1964   product(ccstr, SharedArchiveFile, NULL,                                   \
1965           "Override the default location of the CDS archive file")          \
1966                                                                             \
1967   product(ccstr, ArchiveClassesAtExit, NULL,                                \
1968           "The path and name of the dynamic archive file")                  \
1969                                                                             \
1970   product(ccstr, ExtraSharedClassListFile, NULL,                            \
1971           "Extra classlist for building the CDS archive file")              \
1972                                                                             \
1973   product(intx, ArchiveRelocationMode, 0, DIAGNOSTIC,                       \
1974            "(0) first map at preferred address, and if "                    \
1975            "unsuccessful, map at alternative address (default); "           \
1976            "(1) always map at alternative address; "                        \
1977            "(2) always map at preferred address, and if unsuccessful, "     \
1978            "do not map the archive")                                        \
1979            range(0, 2)                                                      \
1980                                                                             \
1981   product(size_t, ArrayAllocatorMallocLimit, (size_t)-1, EXPERIMENTAL,      \
1982           "Allocation less than this value will be allocated "              \
1983           "using malloc. Larger allocations will use mmap.")                \
1984                                                                             \
1985   product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL,                  \
1986           "Accesses to all variables should always be atomic")              \
1987                                                                             \
1988   product(bool, UseUnalignedAccesses, false, DIAGNOSTIC,                    \
1989           "Use unaligned memory accesses in Unsafe")                        \
1990                                                                             \
1991   product_pd(bool, PreserveFramePointer,                                    \
1992              "Use the FP register for holding the frame pointer "           \
1993              "and not as a general purpose register.")                      \
1994                                                                             \
1995   product(size_t, AsyncLogBufferSize, 2*M,                                  \
1996           "Memory budget (in bytes) for the buffer of Asynchronous "        \
1997           "Logging (-Xlog:async).")                                         \
1998           range(100*K, 50*M)                                                \
1999                                                                             \
2000   product(bool, CheckIntrinsics, true, DIAGNOSTIC,                          \
2001              "When a class C is loaded, check that "                        \
2002              "(1) all intrinsics defined by the VM for class C are present "\
2003              "in the loaded class file and are marked with the "            \
2004              "@IntrinsicCandidate annotation, that "                        \
2005              "(2) there is an intrinsic registered for all loaded methods " \
2006              "that are annotated with the @IntrinsicCandidate annotation, " \
2007              "and that "                                                    \
2008              "(3) no orphan methods exist for class C (i.e., methods for "  \
2009              "which the VM declares an intrinsic but that are not declared "\
2010              "in the loaded class C. "                                      \
2011              "Check (3) is available only in debug builds.")                \
2012                                                                             \
2013   product_pd(intx, InitArrayShortSize, DIAGNOSTIC,                          \
2014           "Threshold small size (in bytes) for clearing arrays. "           \
2015           "Anything this size or smaller may get converted to discrete "    \
2016           "scalar stores.")                                                 \
2017           range(0, max_intx)                                                \
2018           constraint(InitArrayShortSizeConstraintFunc, AfterErgo)           \
2019                                                                             \
2020   product(ccstr, AllocateHeapAt, NULL,                                      \
2021           "Path to the directory where a temporary file will be created "   \
2022           "to use as the backing store for Java Heap.")                     \
2023                                                                             \
2024   product(bool, LoomGenCode, true,                                          \
2025           "Generate oopmap code")                                           \
2026                                                                             \
2027   develop(bool, LoomDeoptAfterThaw, false,                                  \
2028           "Deopt stack after thaw")                                         \
2029                                                                             \
2030   develop(bool, LoomVerifyAfterThaw, false,                                 \
2031           "Verify stack after thaw")                                        \
2032                                                                             \
2033   product(bool, UseContinuationStrong, true,                                \
2034           "The weak keepalive is considered strong on stack")               \
2035                                                                             \
2036   product(bool, TrimContinuationChunksInGC, false,                          \
2037          "Trim stack chunks when copying objects in GC")                    \
2038                                                                             \
2039   product(bool, UseChunkBitmaps, false,                                    \
2040          "Generate oop bitmaps for continuation chunks")                    \
2041                                                                             \
2042   product(bool, UseContinuationFastPath, true,                              \
2043           "Use fast-path frame walking in continuations")                   \
2044                                                                             \
2045   product(bool, UseContinuationStreamingCopy, false,                        \
2046           "Use streaming memory when copying continuation stack chunks")    \
2047                                                                             \
2048   develop(bool, VerifyContinuations, true,                                  \
2049           "Verify continuation consistency")                                \
2050                                                                             \
2051   product(intx, ScopeLocalCacheSize, 16,                                    \
2052           "Size of the cache for scoped values")                            \
2053            range(0, max_intx)                                               \
2054            constraint(ScopeLocalCacheSizeConstraintFunc, AtParse)           \
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   develop(bool, TraceOptimizedUpcallStubs, false,                              \
2093                 "Trace optimized upcall stub generation")                      \
2094 
2095 // end of RUNTIME_FLAGS
2096 
2097 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2098 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2099 DECLARE_FLAGS(RUNTIME_FLAGS)
2100 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2101 
2102 #endif // SHARE_RUNTIME_GLOBALS_HPP