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 CSR).  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 CSR request 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, UseAESIntrinsics, false, DIAGNOSTIC,                        \
 318           "Use intrinsics for AES versions of crypto")                      \
 319                                                                             \
 320   product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC,                     \
 321           "Use intrinsics for the paralleled version of AES/CTR crypto")    \
 322                                                                             \
 323   product(bool, UseMD5Intrinsics, false, DIAGNOSTIC,                        \
 324           "Use intrinsics for MD5 crypto hash function")                    \
 325                                                                             \
 326   product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC,                       \
 327           "Use intrinsics for SHA-1 crypto hash function. "                 \
 328           "Requires that UseSHA is enabled.")                               \
 329                                                                             \
 330   product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC,                     \
 331           "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. "  \
 332           "Requires that UseSHA is enabled.")                               \
 333                                                                             \
 334   product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC,                     \
 335           "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. "  \
 336           "Requires that UseSHA is enabled.")                               \
 337                                                                             \
 338   product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC,                       \
 339           "Use intrinsics for SHA3 crypto hash function. "                  \
 340           "Requires that UseSHA is enabled.")                               \
 341                                                                             \
 342   product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC,                      \
 343           "use intrinsics for java.util.zip.CRC32")                         \
 344                                                                             \
 345   product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC,                     \
 346           "use intrinsics for java.util.zip.CRC32C")                        \
 347                                                                             \
 348   product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC,                    \
 349           "use intrinsics for java.util.zip.Adler32")                       \
 350                                                                             \
 351   product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC,          \
 352           "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
 353                                                                             \
 354   product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC,                    \
 355           "Enables intrinsification of Math.copySign")                      \
 356                                                                             \
 357   product(bool, UseSignumIntrinsic, false, DIAGNOSTIC,                      \
 358           "Enables intrinsification of Math.signum")                        \
 359                                                                             \
 360   product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC,                      \
 361          "do not expand intrinsics whose (internal) names appear here")     \
 362          constraint(DisableIntrinsicConstraintFunc,AfterErgo)               \
 363                                                                             \
 364   product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC,                      \
 365          "Control intrinsics using a list of +/- (internal) names, "        \
 366          "separated by commas")                                             \
 367          constraint(ControlIntrinsicConstraintFunc,AfterErgo)               \
 368                                                                             \
 369   develop(bool, TraceCallFixup, false,                                      \
 370           "Trace all call fixups")                                          \
 371                                                                             \
 372   develop(bool, DeoptimizeALot, false,                                      \
 373           "Deoptimize at every exit from the runtime system")               \
 374                                                                             \
 375   notproduct(ccstrlist, DeoptimizeOnlyAt, "",                               \
 376           "A comma separated list of bcis to deoptimize at")                \
 377                                                                             \
 378   develop(bool, DeoptimizeRandom, false,                                    \
 379           "Deoptimize random frames on random exit from the runtime system")\
 380                                                                             \
 381   notproduct(bool, ZombieALot, false,                                       \
 382           "Create zombies (non-entrant) at exit from the runtime system")   \
 383                                                                             \
 384   notproduct(bool, WalkStackALot, false,                                    \
 385           "Trace stack (no print) at every exit from the runtime system")   \
 386                                                                             \
 387   develop(bool, DeoptimizeObjectsALot, false,                               \
 388           "For testing purposes concurrent threads revert optimizations "   \
 389           "based on escape analysis at intervals given with "               \
 390           "DeoptimizeObjectsALotInterval=n. The thread count is given "     \
 391           "with DeoptimizeObjectsALotThreadCountSingle and "                \
 392           "DeoptimizeObjectsALotThreadCountAll.")                           \
 393                                                                             \
 394   develop(uint64_t, DeoptimizeObjectsALotInterval, 5,                       \
 395           "Interval for DeoptimizeObjectsALot.")                            \
 396           range(0, max_jlong)                                               \
 397                                                                             \
 398   develop(int, DeoptimizeObjectsALotThreadCountSingle, 1,                   \
 399           "The number of threads that revert optimizations based on "       \
 400           "escape analysis for a single thread if DeoptimizeObjectsALot "   \
 401           "is enabled. The target thread is selected round robin." )        \
 402           range(0, max_jint)                                                \
 403                                                                             \
 404   develop(int, DeoptimizeObjectsALotThreadCountAll, 1,                      \
 405           "The number of threads that revert optimizations based on "       \
 406           "escape analysis for all threads if DeoptimizeObjectsALot "       \
 407           "is enabled." )                                                   \
 408           range(0, max_jint)                                                \
 409                                                                             \
 410   notproduct(bool, VerifyLastFrame, false,                                  \
 411           "Verify oops on last frame on entry to VM")                       \
 412                                                                             \
 413   product(bool, SafepointTimeout, false,                                    \
 414           "Time out and warn or fail after SafepointTimeoutDelay "          \
 415           "milliseconds if failed to reach safepoint")                      \
 416                                                                             \
 417   product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC,               \
 418           "Abort upon failure to reach safepoint (see SafepointTimeout)")   \
 419                                                                             \
 420   product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC,             \
 421           "Abort upon failure to complete VM operation promptly")           \
 422                                                                             \
 423   product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC,         \
 424           "Delay in milliseconds for option AbortVMOnVMOperationTimeout")   \
 425           range(0, max_intx)                                                \
 426                                                                             \
 427   product(bool, MaxFDLimit, true,                                           \
 428           "Bump the number of file descriptors to maximum (Unix only)")     \
 429                                                                             \
 430   product(bool, LogEvents, true, DIAGNOSTIC,                                \
 431           "Enable the various ring buffer event logs")                      \
 432                                                                             \
 433   product(uintx, LogEventsBufferEntries, 20, DIAGNOSTIC,                    \
 434           "Number of ring buffer event logs")                               \
 435           range(1, NOT_LP64(1*K) LP64_ONLY(1*M))                            \
 436                                                                             \
 437   product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC,               \
 438           "Enable the Java bytecode verifier for remote classes")           \
 439                                                                             \
 440   product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC,               \
 441           "Enable the Java bytecode verifier for local classes")            \
 442                                                                             \
 443   develop(bool, VerifyStackAtCalls, false,                                  \
 444           "Verify that the stack pointer is unchanged after calls")         \
 445                                                                             \
 446   develop(bool, TraceJavaAssertions, false,                                 \
 447           "Trace java language assertions")                                 \
 448                                                                             \
 449   notproduct(bool, VerifyCodeCache, false,                                  \
 450           "Verify code cache on memory allocation/deallocation")            \
 451                                                                             \
 452   develop(bool, UseMallocOnly, false,                                       \
 453           "Use only malloc/free for allocation (no resource area/arena). "  \
 454           "Used to help diagnose memory stomping bugs.")                    \
 455                                                                             \
 456   develop(bool, ZapResourceArea, trueInDebug,                               \
 457           "Zap freed resource/arena space")                                 \
 458                                                                             \
 459   notproduct(bool, ZapVMHandleArea, trueInDebug,                            \
 460           "Zap freed VM handle space")                                      \
 461                                                                             \
 462   notproduct(bool, ZapStackSegments, trueInDebug,                           \
 463           "Zap allocated/freed stack segments")                             \
 464                                                                             \
 465   develop(bool, ZapUnusedHeapArea, trueInDebug,                             \
 466           "Zap unused heap space")                                          \
 467                                                                             \
 468   develop(bool, CheckZapUnusedHeapArea, false,                              \
 469           "Check zapping of unused heap space")                             \
 470                                                                             \
 471   develop(bool, ZapFillerObjects, trueInDebug,                              \
 472           "Zap filler objects")                                             \
 473                                                                             \
 474   product(bool, ExecutingUnitTests, false,                                  \
 475           "Whether the JVM is running unit tests or not")                   \
 476                                                                             \
 477   develop(uintx, ErrorHandlerTest, 0,                                       \
 478           "If > 0, provokes an error after VM initialization; the value "   \
 479           "determines which error to provoke. See controlled_crash() "      \
 480           "in vmError.cpp.")                                                \
 481           range(0, 17)                                                      \
 482                                                                             \
 483   develop(uintx, TestCrashInErrorHandler, 0,                                \
 484           "If > 0, provokes an error inside VM error handler (a secondary " \
 485           "crash). see controlled_crash() in vmError.cpp")                  \
 486           range(0, 17)                                                      \
 487                                                                             \
 488   develop(bool, TestSafeFetchInErrorHandler, false   ,                      \
 489           "If true, tests SafeFetch inside error handler.")                 \
 490                                                                             \
 491   develop(bool, TestUnresponsiveErrorHandler, false,                        \
 492           "If true, simulates an unresponsive error handler.")              \
 493                                                                             \
 494   develop(bool, Verbose, false,                                             \
 495           "Print additional debugging information from other modes")        \
 496                                                                             \
 497   develop(bool, PrintMiscellaneous, false,                                  \
 498           "Print uncategorized debugging information (requires +Verbose)")  \
 499                                                                             \
 500   develop(bool, WizardMode, false,                                          \
 501           "Print much more debugging information")                          \
 502                                                                             \
 503   product(bool, ShowMessageBoxOnError, false,                               \
 504           "Keep process alive on VM fatal error")                           \
 505                                                                             \
 506   product(bool, CreateCoredumpOnCrash, true,                                \
 507           "Create core/mini dump on VM fatal error")                        \
 508                                                                             \
 509   product(uint64_t, ErrorLogTimeout, 2 * 60,                                \
 510           "Timeout, in seconds, to limit the time spent on writing an "     \
 511           "error log in case of a crash.")                                  \
 512           range(0, (uint64_t)max_jlong/1000)                                \
 513                                                                             \
 514   product(bool, SuppressFatalErrorMessage, false,                           \
 515           "Report NO fatal error message (avoid deadlock)")                 \
 516                                                                             \
 517   product(ccstrlist, OnError, "",                                           \
 518           "Run user-defined commands on fatal error; see VMError.cpp "      \
 519           "for examples")                                                   \
 520                                                                             \
 521   product(ccstrlist, OnOutOfMemoryError, "",                                \
 522           "Run user-defined commands on first java.lang.OutOfMemoryError "  \
 523           "thrown from JVM")                                                \
 524                                                                             \
 525   product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE,                    \
 526           "Dump heap to file before any major stop-the-world GC")           \
 527                                                                             \
 528   product(bool, HeapDumpAfterFullGC, false, MANAGEABLE,                     \
 529           "Dump heap to file after any major stop-the-world GC")            \
 530                                                                             \
 531   product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE,              \
 532           "Dump heap to file when java.lang.OutOfMemoryError is thrown "    \
 533           "from JVM")                                                       \
 534                                                                             \
 535   product(ccstr, HeapDumpPath, NULL, MANAGEABLE,                            \
 536           "When HeapDumpOnOutOfMemoryError is on, the path (filename or "   \
 537           "directory) of the dump file (defaults to java_pid<pid>.hprof "   \
 538           "in the working directory)")                                      \
 539                                                                             \
 540   product(intx, HeapDumpGzipLevel, 0, MANAGEABLE,                           \
 541           "When HeapDumpOnOutOfMemoryError is on, the gzip compression "    \
 542           "level of the dump file. 0 (the default) disables gzip "          \
 543           "compression. Otherwise the level must be between 1 and 9.")      \
 544           range(0, 9)                                                       \
 545                                                                             \
 546   product(ccstr, NativeMemoryTracking, "off",                               \
 547           "Native memory tracking options")                                 \
 548                                                                             \
 549   product(bool, PrintNMTStatistics, false, DIAGNOSTIC,                      \
 550           "Print native memory tracking summary data if it is on")          \
 551                                                                             \
 552   product(bool, LogCompilation, false, DIAGNOSTIC,                          \
 553           "Log compilation activity in detail to LogFile")                  \
 554                                                                             \
 555   product(bool, PrintCompilation, false,                                    \
 556           "Print compilations")                                             \
 557                                                                             \
 558   product(intx, RepeatCompilation, 0, DIAGNOSTIC,                           \
 559           "Repeat compilation without installing code (number of times)")   \
 560           range(0, max_jint)                                                \
 561                                                                             \
 562   product(bool, PrintExtendedThreadInfo, false,                             \
 563           "Print more information in thread dump")                          \
 564                                                                             \
 565   product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC,                         \
 566           "0: do not allow scavengable oops in the code cache; "            \
 567           "1: allow scavenging from the code cache; "                       \
 568           "2: emit as many constants as the compiler can see")              \
 569           range(0, 2)                                                       \
 570                                                                             \
 571   product(bool, AlwaysRestoreFPU, false,                                    \
 572           "Restore the FPU control word after every JNI call (expensive)")  \
 573                                                                             \
 574   product(bool, PrintCompilation2, false, DIAGNOSTIC,                       \
 575           "Print additional statistics per compilation")                    \
 576                                                                             \
 577   product(bool, PrintAdapterHandlers, false, DIAGNOSTIC,                    \
 578           "Print code generated for i2c/c2i adapters")                      \
 579                                                                             \
 580   product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC,                \
 581           "Verify that i2c/c2i adapters are called properly")               \
 582                                                                             \
 583   develop(bool, VerifyAdapterSharing, false,                                \
 584           "Verify that the code for shared adapters is the equivalent")     \
 585                                                                             \
 586   product(bool, PrintAssembly, false, DIAGNOSTIC,                           \
 587           "Print assembly code (using external disassembler.so)")           \
 588                                                                             \
 589   product(ccstr, PrintAssemblyOptions, NULL, DIAGNOSTIC,                    \
 590           "Print options string passed to disassembler.so")                 \
 591                                                                             \
 592   notproduct(bool, PrintNMethodStatistics, false,                           \
 593           "Print a summary statistic for the generated nmethods")           \
 594                                                                             \
 595   product(bool, PrintNMethods, false, DIAGNOSTIC,                           \
 596           "Print assembly code for nmethods when generated")                \
 597                                                                             \
 598   product(bool, PrintNativeNMethods, false, DIAGNOSTIC,                     \
 599           "Print assembly code for native nmethods when generated")         \
 600                                                                             \
 601   develop(bool, PrintDebugInfo, false,                                      \
 602           "Print debug information for all nmethods when generated")        \
 603                                                                             \
 604   develop(bool, PrintRelocations, false,                                    \
 605           "Print relocation information for all nmethods when generated")   \
 606                                                                             \
 607   develop(bool, PrintDependencies, false,                                   \
 608           "Print dependency information for all nmethods when generated")   \
 609                                                                             \
 610   develop(bool, PrintExceptionHandlers, false,                              \
 611           "Print exception handler tables for all nmethods when generated") \
 612                                                                             \
 613   develop(bool, StressCompiledExceptionHandlers, false,                     \
 614           "Exercise compiled exception handlers")                           \
 615                                                                             \
 616   develop(bool, InterceptOSException, false,                                \
 617           "Start debugger when an implicit OS (e.g. NULL) "                 \
 618           "exception happens")                                              \
 619                                                                             \
 620   product(bool, PrintCodeCache, false,                                      \
 621           "Print the code cache memory usage when exiting")                 \
 622                                                                             \
 623   develop(bool, PrintCodeCache2, false,                                     \
 624           "Print detailed usage information on the code cache when exiting")\
 625                                                                             \
 626   product(bool, PrintCodeCacheOnCompilation, false,                         \
 627           "Print the code cache memory usage each time a method is "        \
 628           "compiled")                                                       \
 629                                                                             \
 630   product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC,                  \
 631           "Print code heap usage statistics on exit and on full condition") \
 632                                                                             \
 633   product(bool, PrintStubCode, false, DIAGNOSTIC,                           \
 634           "Print generated stub code")                                      \
 635                                                                             \
 636   product(bool, StackTraceInThrowable, true,                                \
 637           "Collect backtrace in throwable when exception happens")          \
 638                                                                             \
 639   product(bool, OmitStackTraceInFastThrow, true,                            \
 640           "Omit backtraces for some 'hot' exceptions in optimized code")    \
 641                                                                             \
 642   product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE,       \
 643           "Show exception messages from RuntimeExceptions that contain "    \
 644           "snippets of the failing code. Disable this to improve privacy.") \
 645                                                                             \
 646   product(bool, PrintWarnings, true,                                        \
 647           "Print JVM warnings to output stream")                            \
 648                                                                             \
 649   product(bool, RegisterFinalizersAtInit, true,                             \
 650           "Register finalizable objects at end of Object.<init> or "        \
 651           "after allocation")                                               \
 652                                                                             \
 653   develop(bool, RegisterReferences, true,                                   \
 654           "Tell whether the VM should register soft/weak/final/phantom "    \
 655           "references")                                                     \
 656                                                                             \
 657   develop(bool, PrintCodeCacheExtension, false,                             \
 658           "Print extension of code cache")                                  \
 659                                                                             \
 660   develop(bool, UsePrivilegedStack, true,                                   \
 661           "Enable the security JVM functions")                              \
 662                                                                             \
 663   product(bool, ClassUnloading, true,                                       \
 664           "Do unloading of classes")                                        \
 665                                                                             \
 666   product(bool, ClassUnloadingWithConcurrentMark, true,                     \
 667           "Do unloading of classes with a concurrent marking cycle")        \
 668                                                                             \
 669   notproduct(bool, PrintSystemDictionaryAtExit, false,                      \
 670           "Print the system dictionary at exit")                            \
 671                                                                             \
 672   notproduct(bool, PrintClassLoaderDataGraphAtExit, false,                  \
 673           "Print the class loader data graph at exit")                      \
 674                                                                             \
 675   product(bool, DynamicallyResizeSystemDictionaries, true, DIAGNOSTIC,      \
 676           "Dynamically resize system dictionaries as needed")               \
 677                                                                             \
 678   product(bool, AllowParallelDefineClass, false,                            \
 679           "Allow parallel defineClass requests for class loaders "          \
 680           "registering as parallel capable")                                \
 681                                                                             \
 682   product_pd(bool, DontYieldALot,                                           \
 683           "Throw away obvious excess yield calls")                          \
 684                                                                             \
 685   product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL,     \
 686                "Disable the use of stack guard pages if the JVM is loaded " \
 687                "on the primordial process thread")                          \
 688                                                                             \
 689   /* notice: the max range value here is max_jint, not max_intx  */         \
 690   /* because of overflow issue                                   */         \
 691   product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC,                    \
 692           "Async deflate idle monitors every so many milliseconds when "    \
 693           "MonitorUsedDeflationThreshold is exceeded (0 is off).")          \
 694           range(0, max_jint)                                                \
 695                                                                             \
 696   product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC,           \
 697           "Used to estimate a variable ceiling based on number of threads " \
 698           "for use with MonitorUsedDeflationThreshold (0 is off).")         \
 699           range(0, max_uintx)                                               \
 700                                                                             \
 701   /* notice: the max range value here is max_jint, not max_intx  */         \
 702   /* because of overflow issue                                   */         \
 703   product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC,                   \
 704           "The maximum number of monitors to deflate, unlink and delete "   \
 705           "at one time (minimum is 1024).")                      \
 706           range(1024, max_jint)                                             \
 707                                                                             \
 708   product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC,              \
 709           "Percentage of used monitors before triggering deflation (0 is "  \
 710           "off). The check is performed on GuaranteedSafepointInterval "    \
 711           "or AsyncDeflationInterval.")                                     \
 712           range(0, 100)                                                     \
 713                                                                             \
 714   product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC,                \
 715           "Max number of no progress async deflation attempts to tolerate " \
 716           "before adjusting the in_use_list_ceiling up (0 is off).")        \
 717           range(0, max_uintx)                                               \
 718                                                                             \
 719   product(intx, hashCode, 5, EXPERIMENTAL,                                  \
 720                "(Unstable) select hashCode generation algorithm")           \
 721                                                                             \
 722   product(bool, FilterSpuriousWakeups, true,                                \
 723           "(Deprecated) When true prevents OS-level spurious, or premature,"\
 724           " wakeups from Object.wait (Ignored for Windows)")                \
 725                                                                             \
 726   product(bool, ReduceSignalUsage, false,                                   \
 727           "Reduce the use of OS signals in Java and/or the VM")             \
 728                                                                             \
 729   develop(bool, LoadLineNumberTables, true,                                 \
 730           "Tell whether the class file parser loads line number tables")    \
 731                                                                             \
 732   develop(bool, LoadLocalVariableTables, true,                              \
 733           "Tell whether the class file parser loads local variable tables") \
 734                                                                             \
 735   develop(bool, LoadLocalVariableTypeTables, true,                          \
 736           "Tell whether the class file parser loads local variable type"    \
 737           "tables")                                                         \
 738                                                                             \
 739   product(bool, AllowUserSignalHandlers, false,                             \
 740           "Application will install primary signal handlers for the JVM "   \
 741           "(Unix only)")                                                    \
 742                                                                             \
 743   product(bool, UseSignalChaining, true,                                    \
 744           "Use signal-chaining to invoke signal handlers installed "        \
 745           "by the application (Unix only)")                                 \
 746                                                                             \
 747   product(bool, RestoreMXCSROnJNICalls, false,                              \
 748           "Restore MXCSR when returning from JNI calls")                    \
 749                                                                             \
 750   product(bool, CheckJNICalls, false,                                       \
 751           "Verify all arguments to JNI calls")                              \
 752                                                                             \
 753   product(bool, UseFastJNIAccessors, true,                                  \
 754           "Use optimized versions of Get<Primitive>Field")                  \
 755                                                                             \
 756   product(intx, MaxJNILocalCapacity, 65536,                                 \
 757           "Maximum allowable local JNI handle capacity to "                 \
 758           "EnsureLocalCapacity() and PushLocalFrame(), "                    \
 759           "where <= 0 is unlimited, default: 65536")                        \
 760           range(min_intx, max_intx)                                         \
 761                                                                             \
 762   product(bool, EagerXrunInit, false,                                       \
 763           "Eagerly initialize -Xrun libraries; allows startup profiling, "  \
 764           "but not all -Xrun libraries may support the state of the VM "    \
 765           "at this time")                                                   \
 766                                                                             \
 767   product(bool, PreserveAllAnnotations, false,                              \
 768           "Preserve RuntimeInvisibleAnnotations as well "                   \
 769           "as RuntimeVisibleAnnotations")                                   \
 770                                                                             \
 771   develop(uintx, PreallocatedOutOfMemoryErrorCount, 4,                      \
 772           "Number of OutOfMemoryErrors preallocated with backtrace")        \
 773                                                                             \
 774   product(bool, UseXMMForArrayCopy, false,                                  \
 775           "Use SSE2 MOVQ instruction for Arraycopy")                        \
 776                                                                             \
 777   notproduct(bool, PrintFieldLayout, false,                                 \
 778           "Print field layout for each class")                              \
 779                                                                             \
 780   /* Need to limit the extent of the padding to reasonable size.          */\
 781   /* 8K is well beyond the reasonable HW cache line size, even with       */\
 782   /* aggressive prefetching, while still leaving the room for segregating */\
 783   /* among the distinct pages.                                            */\
 784   product(intx, ContendedPaddingWidth, 128,                                 \
 785           "How many bytes to pad the fields/classes marked @Contended with")\
 786           range(0, 8192)                                                    \
 787           constraint(ContendedPaddingWidthConstraintFunc,AfterErgo)         \
 788                                                                             \
 789   product(bool, EnableContended, true,                                      \
 790           "Enable @Contended annotation support")                           \
 791                                                                             \
 792   product(bool, RestrictContended, true,                                    \
 793           "Restrict @Contended to trusted classes")                         \
 794                                                                             \
 795   product(intx, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC,             \
 796              "Detect and take action upon identifying synchronization on "  \
 797              "value based classes. Modes: "                                 \
 798              "0: off; "                                                     \
 799              "1: exit with fatal error; "                                   \
 800              "2: log message to stdout. Output file can be specified with " \
 801              "   -Xlog:valuebasedclasses. If JFR is running it will "       \
 802              "   also generate JFR events.")                                \
 803              range(0, 2)                                                    \
 804                                                                             \
 805   product(bool, ExitOnOutOfMemoryError, false,                              \
 806           "JVM exits on the first occurrence of an out-of-memory error "    \
 807           "thrown from JVM")                                                \
 808                                                                             \
 809   product(bool, CrashOnOutOfMemoryError, false,                             \
 810           "JVM aborts, producing an error log and core/mini dump, on the "  \
 811           "first occurrence of an out-of-memory error thrown from JVM")     \
 812                                                                             \
 813   /* tracing */                                                             \
 814                                                                             \
 815   develop(bool, StressRewriter, false,                                      \
 816           "Stress linktime bytecode rewriting")                             \
 817                                                                             \
 818   product(ccstr, TraceJVMTI, NULL,                                          \
 819           "Trace flags for JVMTI functions and events")                     \
 820                                                                             \
 821   product(bool, StressLdcRewrite, false, DIAGNOSTIC,                        \
 822           "Force ldc -> ldc_w rewrite during RedefineClasses. "             \
 823           "This option can change an EMCP method into an obsolete method "  \
 824           "and can affect tests that expect specific methods to be EMCP. "  \
 825           "This option should be used with caution.")                       \
 826                                                                             \
 827   product(bool, AllowRedefinitionToAddDeleteMethods, false,                 \
 828           "(Deprecated) Allow redefinition to add and delete private "      \
 829           "static or final methods for compatibility with old releases")    \
 830                                                                             \
 831   develop(bool, TraceBytecodes, false,                                      \
 832           "Trace bytecode execution")                                       \
 833                                                                             \
 834   develop(bool, TraceICs, false,                                            \
 835           "Trace inline cache changes")                                     \
 836                                                                             \
 837   notproduct(bool, TraceInvocationCounterOverflow, false,                   \
 838           "Trace method invocation counter overflow")                       \
 839                                                                             \
 840   develop(bool, TraceInlineCacheClearing, false,                            \
 841           "Trace clearing of inline caches in nmethods")                    \
 842                                                                             \
 843   develop(bool, TraceDependencies, false,                                   \
 844           "Trace dependencies")                                             \
 845                                                                             \
 846   develop(bool, VerifyDependencies, trueInDebug,                            \
 847           "Exercise and verify the compilation dependency mechanism")       \
 848                                                                             \
 849   develop(bool, TraceNewOopMapGeneration, false,                            \
 850           "Trace OopMapGeneration")                                         \
 851                                                                             \
 852   develop(bool, TraceNewOopMapGenerationDetailed, false,                    \
 853           "Trace OopMapGeneration: print detailed cell states")             \
 854                                                                             \
 855   develop(bool, TimeOopMap, false,                                          \
 856           "Time calls to GenerateOopMap::compute_map() in sum")             \
 857                                                                             \
 858   develop(bool, TimeOopMap2, false,                                         \
 859           "Time calls to GenerateOopMap::compute_map() individually")       \
 860                                                                             \
 861   develop(bool, TraceOopMapRewrites, false,                                 \
 862           "Trace rewriting of methods during oop map generation")           \
 863                                                                             \
 864   develop(bool, TraceICBuffer, false,                                       \
 865           "Trace usage of IC buffer")                                       \
 866                                                                             \
 867   develop(bool, TraceCompiledIC, false,                                     \
 868           "Trace changes of compiled IC")                                   \
 869                                                                             \
 870   develop(bool, FLSVerifyDictionary, false,                                 \
 871           "Do lots of (expensive) FLS dictionary verification")             \
 872                                                                             \
 873                                                                             \
 874   notproduct(bool, CheckMemoryInitialization, false,                        \
 875           "Check memory initialization")                                    \
 876                                                                             \
 877   product(uintx, ProcessDistributionStride, 4,                              \
 878           "Stride through processors when distributing processes")          \
 879           range(0, max_juint)                                               \
 880                                                                             \
 881   develop(bool, TraceFinalizerRegistration, false,                          \
 882           "Trace registration of final references")                         \
 883                                                                             \
 884   product(bool, IgnoreEmptyClassPaths, false,                               \
 885           "Ignore empty path elements in -classpath")                       \
 886                                                                             \
 887   product(bool, PrintHeapAtSIGBREAK, true,                                  \
 888           "Print heap layout in response to SIGBREAK")                      \
 889                                                                             \
 890   product(bool, PrintClassHistogram, false, MANAGEABLE,                     \
 891           "Print a histogram of class instances")                           \
 892                                                                             \
 893   product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL,              \
 894           "The percentage of the used heap that the instances of a class "  \
 895           "must occupy for the class to generate a trace event")            \
 896           range(0.0, 100.0)                                                 \
 897                                                                             \
 898   /* JVMTI heap profiling */                                                \
 899                                                                             \
 900   product(bool, VerifyBeforeIteration, false, DIAGNOSTIC,                   \
 901           "Verify memory system before JVMTI iteration")                    \
 902                                                                             \
 903   /* compiler */                                                            \
 904                                                                             \
 905   /* notice: the max range value here is max_jint, not max_intx  */         \
 906   /* because of overflow issue                                   */         \
 907   product(intx, CICompilerCount, CI_COMPILER_COUNT,                         \
 908           "Number of compiler threads to run")                              \
 909           range(0, max_jint)                                                \
 910           constraint(CICompilerCountConstraintFunc, AfterErgo)              \
 911                                                                             \
 912   product(bool, UseDynamicNumberOfCompilerThreads, true,                    \
 913           "Dynamically choose the number of parallel compiler threads")     \
 914                                                                             \
 915   product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC,            \
 916              "Reduce the number of parallel compiler threads when they "    \
 917              "are not used")                                                \
 918                                                                             \
 919   product(bool, TraceCompilerThreads, false, DIAGNOSTIC,                    \
 920              "Trace creation and removal of compiler threads")              \
 921                                                                             \
 922   develop(bool, InjectCompilerCreationFailure, false,                       \
 923           "Inject thread creation failures for "                            \
 924           "UseDynamicNumberOfCompilerThreads")                              \
 925                                                                             \
 926   develop(bool, GenerateSynchronizationCode, true,                          \
 927           "generate locking/unlocking code for synchronized methods and "   \
 928           "monitors")                                                       \
 929                                                                             \
 930   develop(bool, GenerateRangeChecks, true,                                  \
 931           "Generate range checks for array accesses")                       \
 932                                                                             \
 933   product_pd(bool, ImplicitNullChecks, DIAGNOSTIC,                          \
 934           "Generate code for implicit null checks")                         \
 935                                                                             \
 936   product_pd(bool, TrapBasedNullChecks,                                     \
 937           "Generate code for null checks that uses a cmp and trap "         \
 938           "instruction raising SIGTRAP.  This is only used if an access to" \
 939           "null (+offset) will not raise a SIGSEGV, i.e.,"                  \
 940           "ImplicitNullChecks don't work (PPC64).")                         \
 941                                                                             \
 942   product(bool, EnableThreadSMRExtraValidityChecks, true, DIAGNOSTIC,       \
 943              "Enable Thread SMR extra validity checks")                     \
 944                                                                             \
 945   product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC,         \
 946              "Enable Thread SMR Statistics")                                \
 947                                                                             \
 948   product(bool, UseNotificationThread, true,                                \
 949           "Use Notification Thread")                                        \
 950                                                                             \
 951   product(bool, Inline, true,                                               \
 952           "Enable inlining")                                                \
 953                                                                             \
 954   product(bool, ClipInlining, true,                                         \
 955           "Clip inlining if aggregate method exceeds DesiredMethodLimit")   \
 956                                                                             \
 957   develop(bool, UseCHA, true,                                               \
 958           "Enable CHA")                                                     \
 959                                                                             \
 960   product(bool, UseVtableBasedCHA, true,  DIAGNOSTIC,                       \
 961           "Use vtable information during CHA")                              \
 962                                                                             \
 963   product(bool, UseTypeProfile, true,                                       \
 964           "Check interpreter profile for historically monomorphic calls")   \
 965                                                                             \
 966   product(bool, PrintInlining, false, DIAGNOSTIC,                           \
 967           "Print inlining optimizations")                                   \
 968                                                                             \
 969   product(bool, UsePopCountInstruction, false,                              \
 970           "Use population count instruction")                               \
 971                                                                             \
 972   develop(bool, EagerInitialization, false,                                 \
 973           "Eagerly initialize classes if possible")                         \
 974                                                                             \
 975   product(bool, LogTouchedMethods, false, DIAGNOSTIC,                       \
 976           "Log methods which have been ever touched in runtime")            \
 977                                                                             \
 978   product(bool, PrintTouchedMethodsAtExit, false, DIAGNOSTIC,               \
 979           "Print all methods that have been ever touched in runtime")       \
 980                                                                             \
 981   develop(bool, TraceMethodReplacement, false,                              \
 982           "Print when methods are replaced do to recompilation")            \
 983                                                                             \
 984   develop(bool, PrintMethodFlushing, false,                                 \
 985           "Print the nmethods being flushed")                               \
 986                                                                             \
 987   product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC,           \
 988           "print statistics about method flushing")                         \
 989                                                                             \
 990   product(intx, HotMethodDetectionLimit, 100000, DIAGNOSTIC,                \
 991           "Number of compiled code invocations after which "                \
 992           "the method is considered as hot by the flusher")                 \
 993           range(1, max_jint)                                                \
 994                                                                             \
 995   product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC,                       \
 996           "Minimum number of sweeper passes before an nmethod "             \
 997           "can be flushed")                                                 \
 998           range(0, max_intx)                                                \
 999                                                                             \
1000   product(bool, UseCodeAging, true,                                         \
1001           "Insert counter to detect warm methods")                          \
1002                                                                             \
1003   product(bool, StressCodeAging, false, DIAGNOSTIC,                         \
1004           "Start with counters compiled in")                                \
1005                                                                             \
1006   develop(bool, StressCodeBuffers, false,                                   \
1007           "Exercise code buffer expansion and other rare state changes")    \
1008                                                                             \
1009   product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC,                \
1010           "Generate extra debugging information for non-safepoints in "     \
1011           "nmethods")                                                       \
1012                                                                             \
1013   product(bool, PrintVMOptions, false,                                      \
1014           "Print flags that appeared on the command line")                  \
1015                                                                             \
1016   product(bool, IgnoreUnrecognizedVMOptions, false,                         \
1017           "Ignore unrecognized VM options")                                 \
1018                                                                             \
1019   product(bool, PrintCommandLineFlags, false,                               \
1020           "Print flags specified on command line or set by ergonomics")     \
1021                                                                             \
1022   product(bool, PrintFlagsInitial, false,                                   \
1023           "Print all VM flags before argument processing and exit VM")      \
1024                                                                             \
1025   product(bool, PrintFlagsFinal, false,                                     \
1026           "Print all VM flags after argument and ergonomic processing")     \
1027                                                                             \
1028   notproduct(bool, PrintFlagsWithComments, false,                           \
1029           "Print all VM flags with default values and descriptions and "    \
1030           "exit")                                                           \
1031                                                                             \
1032   product(bool, PrintFlagsRanges, false,                                    \
1033           "Print VM flags and their ranges")                                \
1034                                                                             \
1035   product(bool, SerializeVMOutput, true, DIAGNOSTIC,                        \
1036           "Use a mutex to serialize output to tty and LogFile")             \
1037                                                                             \
1038   product(bool, DisplayVMOutput, true, DIAGNOSTIC,                          \
1039           "Display all VM output on the tty, independently of LogVMOutput") \
1040                                                                             \
1041   product(bool, LogVMOutput, false, DIAGNOSTIC,                             \
1042           "Save VM output to LogFile")                                      \
1043                                                                             \
1044   product(ccstr, LogFile, NULL, DIAGNOSTIC,                                 \
1045           "If LogVMOutput or LogCompilation is on, save VM output to "      \
1046           "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1047                                                                             \
1048   product(ccstr, ErrorFile, NULL,                                           \
1049           "If an error occurs, save the error data to this file "           \
1050           "[default: ./hs_err_pid%p.log] (%p replaced with pid)")           \
1051                                                                             \
1052   product(bool, ExtensiveErrorReports,                                      \
1053           PRODUCT_ONLY(false) NOT_PRODUCT(true),                            \
1054           "Error reports are more extensive.")                              \
1055                                                                             \
1056   product(bool, DisplayVMOutputToStderr, false,                             \
1057           "If DisplayVMOutput is true, display all VM output to stderr")    \
1058                                                                             \
1059   product(bool, DisplayVMOutputToStdout, false,                             \
1060           "If DisplayVMOutput is true, display all VM output to stdout")    \
1061                                                                             \
1062   product(bool, ErrorFileToStderr, false,                                   \
1063           "If true, error data is printed to stderr instead of a file")     \
1064                                                                             \
1065   product(bool, ErrorFileToStdout, false,                                   \
1066           "If true, error data is printed to stdout instead of a file")     \
1067                                                                             \
1068   product(bool, UseHeavyMonitors, false,                                    \
1069           "use heavyweight instead of lightweight Java monitors")           \
1070                                                                             \
1071   product(bool, PrintStringTableStatistics, false,                          \
1072           "print statistics about the StringTable and SymbolTable")         \
1073                                                                             \
1074   product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC,                 \
1075           "verify StringTable contents at exit")                            \
1076                                                                             \
1077   notproduct(bool, PrintSymbolTableSizeHistogram, false,                    \
1078           "print histogram of the symbol table")                            \
1079                                                                             \
1080   product(ccstr, AbortVMOnException, NULL, DIAGNOSTIC,                      \
1081           "Call fatal if this exception is thrown.  Example: "              \
1082           "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1083                                                                             \
1084   product(ccstr, AbortVMOnExceptionMessage, NULL, DIAGNOSTIC,               \
1085           "Call fatal if the exception pointed by AbortVMOnException "      \
1086           "has this message")                                               \
1087                                                                             \
1088   develop(bool, DebugVtables, false,                                        \
1089           "add debugging code to vtable dispatch")                          \
1090                                                                             \
1091   develop(bool, TraceCreateZombies, false,                                  \
1092           "trace creation of zombie nmethods")                              \
1093                                                                             \
1094   product(bool, RangeCheckElimination, true,                                \
1095           "Eliminate range checks")                                         \
1096                                                                             \
1097   develop_pd(bool, UncommonNullCast,                                        \
1098           "track occurrences of null in casts; adjust compiler tactics")    \
1099                                                                             \
1100   develop(bool, TypeProfileCasts,  true,                                    \
1101           "treat casts like calls for purposes of type profiling")          \
1102                                                                             \
1103   develop(bool, TraceLivenessGen, false,                                    \
1104           "Trace the generation of liveness analysis information")          \
1105                                                                             \
1106   notproduct(bool, TraceLivenessQuery, false,                               \
1107           "Trace queries of liveness analysis information")                 \
1108                                                                             \
1109   notproduct(bool, CollectIndexSetStatistics, false,                        \
1110           "Collect information about IndexSets")                            \
1111                                                                             \
1112   develop(intx, FastAllocateSizeLimit, 128*K,                               \
1113           /* Note:  This value is zero mod 1<<13 for a cheap sparc set. */  \
1114           "Inline allocations larger than this in doublewords must go slow")\
1115                                                                             \
1116   product_pd(bool, CompactStrings,                                          \
1117           "Enable Strings to use single byte chars in backing store")       \
1118                                                                             \
1119   product_pd(uintx, TypeProfileLevel,                                       \
1120           "=XYZ, with Z: Type profiling of arguments at call; "             \
1121                      "Y: Type profiling of return value at call; "          \
1122                      "X: Type profiling of parameters to methods; "         \
1123           "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods")             \
1124           constraint(TypeProfileLevelConstraintFunc, AfterErgo)             \
1125                                                                             \
1126   product(intx, TypeProfileArgsLimit,     2,                                \
1127           "max number of call arguments to consider for type profiling")    \
1128           range(0, 16)                                                      \
1129                                                                             \
1130   product(intx, TypeProfileParmsLimit,    2,                                \
1131           "max number of incoming parameters to consider for type profiling"\
1132           ", -1 for all")                                                   \
1133           range(-1, 64)                                                     \
1134                                                                             \
1135   /* statistics */                                                          \
1136   develop(bool, CountCompiledCalls, false,                                  \
1137           "Count method invocations")                                       \
1138                                                                             \
1139   notproduct(bool, ICMissHistogram, false,                                  \
1140           "Produce histogram of IC misses")                                 \
1141                                                                             \
1142   /* interpreter */                                                         \
1143   product_pd(bool, RewriteBytecodes,                                        \
1144           "Allow rewriting of bytecodes (bytecodes are not immutable)")     \
1145                                                                             \
1146   product_pd(bool, RewriteFrequentPairs,                                    \
1147           "Rewrite frequently used bytecode pairs into a single bytecode")  \
1148                                                                             \
1149   product(bool, PrintInterpreter, false, DIAGNOSTIC,                        \
1150           "Print the generated interpreter code")                           \
1151                                                                             \
1152   product(bool, UseInterpreter, true,                                       \
1153           "Use interpreter for non-compiled methods")                       \
1154                                                                             \
1155   develop(bool, UseFastSignatureHandlers, true,                             \
1156           "Use fast signature handlers for native calls")                   \
1157                                                                             \
1158   product(bool, UseLoopCounter, true,                                       \
1159           "Increment invocation counter on backward branch")                \
1160                                                                             \
1161   product_pd(bool, UseOnStackReplacement,                                   \
1162           "Use on stack replacement, calls runtime if invoc. counter "      \
1163           "overflows in loop")                                              \
1164                                                                             \
1165   notproduct(bool, TraceOnStackReplacement, false,                          \
1166           "Trace on stack replacement")                                     \
1167                                                                             \
1168   product_pd(bool, PreferInterpreterNativeStubs,                            \
1169           "Use always interpreter stubs for native methods invoked via "    \
1170           "interpreter")                                                    \
1171                                                                             \
1172   develop(bool, CountBytecodes, false,                                      \
1173           "Count number of bytecodes executed")                             \
1174                                                                             \
1175   develop(bool, PrintBytecodeHistogram, false,                              \
1176           "Print histogram of the executed bytecodes")                      \
1177                                                                             \
1178   develop(bool, PrintBytecodePairHistogram, false,                          \
1179           "Print histogram of the executed bytecode pairs")                 \
1180                                                                             \
1181   product(bool, PrintSignatureHandlers, false, DIAGNOSTIC,                  \
1182           "Print code generated for native method signature handlers")      \
1183                                                                             \
1184   develop(bool, VerifyOops, false,                                          \
1185           "Do plausibility checks for oops")                                \
1186                                                                             \
1187   develop(bool, CheckUnhandledOops, false,                                  \
1188           "Check for unhandled oops in VM code")                            \
1189                                                                             \
1190   develop(bool, VerifyJNIFields, trueInDebug,                               \
1191           "Verify jfieldIDs for instance fields")                           \
1192                                                                             \
1193   notproduct(bool, VerifyJNIEnvThread, false,                               \
1194           "Verify JNIEnv.thread == Thread::current() when entering VM "     \
1195           "from JNI")                                                       \
1196                                                                             \
1197   develop(bool, VerifyFPU, false,                                           \
1198           "Verify FPU state (check for NaN's, etc.)")                       \
1199                                                                             \
1200   develop(bool, VerifyThread, false,                                        \
1201           "Watch the thread register for corruption (SPARC only)")          \
1202                                                                             \
1203   develop(bool, VerifyActivationFrameSize, false,                           \
1204           "Verify that activation frame didn't become smaller than its "    \
1205           "minimal size")                                                   \
1206                                                                             \
1207   develop(bool, TraceFrequencyInlining, false,                              \
1208           "Trace frequency based inlining")                                 \
1209                                                                             \
1210   develop_pd(bool, InlineIntrinsics,                                        \
1211           "Inline intrinsics that can be statically resolved")              \
1212                                                                             \
1213   product_pd(bool, ProfileInterpreter,                                      \
1214           "Profile at the bytecode level during interpretation")            \
1215                                                                             \
1216   develop_pd(bool, ProfileTraps,                                            \
1217           "Profile deoptimization traps at the bytecode level")             \
1218                                                                             \
1219   product(intx, ProfileMaturityPercentage, 20,                              \
1220           "number of method invocations/branches (expressed as % of "       \
1221           "CompileThreshold) before using the method's profile")            \
1222           range(0, 100)                                                     \
1223                                                                             \
1224   product(bool, PrintMethodData, false, DIAGNOSTIC,                         \
1225           "Print the results of +ProfileInterpreter at end of run")         \
1226                                                                             \
1227   develop(bool, VerifyDataPointer, trueInDebug,                             \
1228           "Verify the method data pointer during interpreter profiling")    \
1229                                                                             \
1230   notproduct(bool, CrashGCForDumpingJavaThread, false,                      \
1231           "Manually make GC thread crash then dump java stack trace;  "     \
1232           "Test only")                                                      \
1233                                                                             \
1234   /* compilation */                                                         \
1235   product(bool, UseCompiler, true,                                          \
1236           "Use Just-In-Time compilation")                                   \
1237                                                                             \
1238   product(bool, UseCounterDecay, true,                                      \
1239           "Adjust recompilation counters")                                  \
1240                                                                             \
1241   develop(intx, CounterHalfLifeTime,    30,                                 \
1242           "Half-life time of invocation counters (in seconds)")             \
1243                                                                             \
1244   develop(intx, CounterDecayMinIntervalLength,   500,                       \
1245           "The minimum interval (in milliseconds) between invocation of "   \
1246           "CounterDecay")                                                   \
1247                                                                             \
1248   product(bool, AlwaysCompileLoopMethods, false,                            \
1249           "When using recompilation, never interpret methods "              \
1250           "containing loops")                                               \
1251                                                                             \
1252   product(intx,  AllocatePrefetchStyle, 1,                                  \
1253           "0 = no prefetch, "                                               \
1254           "1 = generate prefetch instructions for each allocation, "        \
1255           "2 = use TLAB watermark to gate allocation prefetch, "            \
1256           "3 = generate one prefetch instruction per cache line")           \
1257           range(0, 3)                                                       \
1258                                                                             \
1259   product(intx,  AllocatePrefetchDistance, -1,                              \
1260           "Distance to prefetch ahead of allocation pointer. "              \
1261           "-1: use system-specific value (automatically determined")        \
1262           constraint(AllocatePrefetchDistanceConstraintFunc,AfterMemoryInit)\
1263                                                                             \
1264   product(intx,  AllocatePrefetchLines, 3,                                  \
1265           "Number of lines to prefetch ahead of array allocation pointer")  \
1266           range(1, 64)                                                      \
1267                                                                             \
1268   product(intx,  AllocateInstancePrefetchLines, 1,                          \
1269           "Number of lines to prefetch ahead of instance allocation "       \
1270           "pointer")                                                        \
1271           range(1, 64)                                                      \
1272                                                                             \
1273   product(intx,  AllocatePrefetchStepSize, 16,                              \
1274           "Step size in bytes of sequential prefetch instructions")         \
1275           range(1, 512)                                                     \
1276           constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1277                                                                             \
1278   product(intx,  AllocatePrefetchInstr, 0,                                  \
1279           "Select instruction to prefetch ahead of allocation pointer")     \
1280           constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit)  \
1281                                                                             \
1282   /* deoptimization */                                                      \
1283   develop(bool, TraceDeoptimization, false,                                 \
1284           "Trace deoptimization")                                           \
1285                                                                             \
1286   develop(bool, PrintDeoptimizationDetails, false,                          \
1287           "Print more information about deoptimization")                    \
1288                                                                             \
1289   develop(bool, DebugDeoptimization, false,                                 \
1290           "Tracing various information while debugging deoptimization")     \
1291                                                                             \
1292   product(intx, SelfDestructTimer, 0,                                       \
1293           "Will cause VM to terminate after a given time (in minutes) "     \
1294           "(0 means off)")                                                  \
1295           range(0, max_intx)                                                \
1296                                                                             \
1297   product(intx, MaxJavaStackTraceDepth, 1024,                               \
1298           "The maximum number of lines in the stack trace for Java "        \
1299           "exceptions (0 means all)")                                       \
1300           range(0, max_jint/2)                                              \
1301                                                                             \
1302   /* notice: the max range value here is max_jint, not max_intx  */         \
1303   /* because of overflow issue                                   */         \
1304   product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC,              \
1305           "Guarantee a safepoint (at least) every so many milliseconds "    \
1306           "(0 means none)")                                                 \
1307           range(0, max_jint)                                                \
1308                                                                             \
1309   product(intx, SafepointTimeoutDelay, 10000,                               \
1310           "Delay in milliseconds for option SafepointTimeout")              \
1311           range(0, max_intx LP64_ONLY(/MICROUNITS))                         \
1312                                                                             \
1313   product(intx, NmethodSweepActivity, 10,                                   \
1314           "Removes cold nmethods from code cache if > 0. Higher values "    \
1315           "result in more aggressive sweeping")                             \
1316           range(0, 2000)                                                    \
1317                                                                             \
1318   notproduct(bool, LogSweeper, false,                                       \
1319           "Keep a ring buffer of sweeper activity")                         \
1320                                                                             \
1321   notproduct(intx, SweeperLogEntries, 1024,                                 \
1322           "Number of records in the ring buffer of sweeper activity")       \
1323                                                                             \
1324   develop(intx, MallocCatchPtr, -1,                                         \
1325           "Hit breakpoint when mallocing/freeing this pointer")             \
1326                                                                             \
1327   notproduct(ccstrlist, SuppressErrorAt, "",                                \
1328           "List of assertions (file:line) to muzzle")                       \
1329                                                                             \
1330   develop(intx, StackPrintLimit, 100,                                       \
1331           "number of stack frames to print in VM-level stack dump")         \
1332                                                                             \
1333   product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC,                       \
1334           "max number of compiled code units to print in error log")        \
1335           range(0, VMError::max_error_log_print_code)                       \
1336                                                                             \
1337   notproduct(intx, MaxElementPrintSize, 256,                                \
1338           "maximum number of elements to print")                            \
1339                                                                             \
1340   notproduct(intx, MaxSubklassPrintSize, 4,                                 \
1341           "maximum number of subklasses to print when printing klass")      \
1342                                                                             \
1343   develop(intx, MaxForceInlineLevel, 100,                                   \
1344           "maximum number of nested calls that are forced for inlining "    \
1345           "(using CompileCommand or marked w/ @ForceInline)")               \
1346           range(0, max_jint)                                                \
1347                                                                             \
1348   product(intx, MinInliningThreshold, 0,                                    \
1349           "(Deprecated) The minimum invocation count a method needs to"     \
1350           "have to be inlined")                                             \
1351           range(0, max_jint)                                                \
1352                                                                             \
1353   develop(intx, MethodHistogramCutoff, 100,                                 \
1354           "The cutoff value for method invocation histogram (+CountCalls)") \
1355                                                                             \
1356   develop(intx, DontYieldALotInterval,    10,                               \
1357           "Interval between which yields will be dropped (milliseconds)")   \
1358                                                                             \
1359   notproduct(intx, DeoptimizeALotInterval,     5,                           \
1360           "Number of exits until DeoptimizeALot kicks in")                  \
1361                                                                             \
1362   notproduct(intx, ZombieALotInterval,     5,                               \
1363           "Number of exits until ZombieALot kicks in")                      \
1364                                                                             \
1365   product(uintx, MallocMaxTestWords,     0, DIAGNOSTIC,                     \
1366           "If non-zero, maximum number of words that malloc/realloc can "   \
1367           "allocate (for testing only)")                                    \
1368           range(0, max_uintx)                                               \
1369                                                                             \
1370   product(intx, TypeProfileWidth, 2,                                        \
1371           "Number of receiver types to record in call/cast profile")        \
1372           range(0, 8)                                                       \
1373                                                                             \
1374   develop(intx, BciProfileWidth,      2,                                    \
1375           "Number of return bci's to record in ret profile")                \
1376                                                                             \
1377   product(intx, PerMethodRecompilationCutoff, 400,                          \
1378           "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1379           range(-1, max_intx)                                               \
1380                                                                             \
1381   product(intx, PerBytecodeRecompilationCutoff, 200,                        \
1382           "Per-BCI limit on repeated recompilation (-1=>'Inf')")            \
1383           range(-1, max_intx)                                               \
1384                                                                             \
1385   product(intx, PerMethodTrapLimit,  100,                                   \
1386           "Limit on traps (of one kind) in a method (includes inlines)")    \
1387           range(0, max_jint)                                                \
1388                                                                             \
1389   product(intx, PerMethodSpecTrapLimit,  5000, EXPERIMENTAL,                \
1390           "Limit on speculative traps (of one kind) in a method "           \
1391           "(includes inlines)")                                             \
1392           range(0, max_jint)                                                \
1393                                                                             \
1394   product(intx, PerBytecodeTrapLimit,  4,                                   \
1395           "Limit on traps (of one kind) at a particular BCI")               \
1396           range(0, max_jint)                                                \
1397                                                                             \
1398   product(intx, SpecTrapLimitExtraEntries,  3, EXPERIMENTAL,                \
1399           "Extra method data trap entries for speculation")                 \
1400                                                                             \
1401   product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC,                   \
1402           "Ratio of call site execution to caller method invocation")       \
1403                                                                             \
1404   product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC,               \
1405           "Minimum ratio of call site execution to caller method"           \
1406           "invocation to be considered for inlining")                       \
1407                                                                             \
1408   develop(intx, InlineThrowCount,    50,                                    \
1409           "Force inlining of interpreted methods that throw this often")    \
1410           range(0, max_jint)                                                \
1411                                                                             \
1412   develop(intx, InlineThrowMaxSize,   200,                                  \
1413           "Force inlining of throwing methods smaller than this")           \
1414           range(0, max_jint)                                                \
1415                                                                             \
1416   product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M),        \
1417           "Initial threshold (in bytes) at which a garbage collection "     \
1418           "is done to reduce Metaspace usage")                              \
1419           constraint(MetaspaceSizeConstraintFunc,AfterErgo)                 \
1420                                                                             \
1421   product(size_t, MaxMetaspaceSize, max_uintx,                              \
1422           "Maximum size of Metaspaces (in bytes)")                          \
1423           constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo)              \
1424                                                                             \
1425   product(size_t, CompressedClassSpaceSize, 1*G,                            \
1426           "Maximum size of class area in Metaspace when compressed "        \
1427           "class pointers are used")                                        \
1428           range(1*M, 3*G)                                                   \
1429                                                                             \
1430   develop(size_t, CompressedClassSpaceBaseAddress, 0,                       \
1431           "Force the class space to be allocated at this address or "       \
1432           "fails VM initialization (requires -Xshare=off.")                 \
1433                                                                             \
1434   product(ccstr, MetaspaceReclaimPolicy, "balanced",                        \
1435           "options: balanced, aggressive, none")                            \
1436                                                                             \
1437   product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC,          \
1438           "Print metaspace statistics upon VM exit.")                       \
1439                                                                             \
1440   develop(bool, MetaspaceGuardAllocations, false,                           \
1441           "Metapace allocations are guarded.")                              \
1442                                                                             \
1443   product(uintx, MinHeapFreeRatio, 40, MANAGEABLE,                          \
1444           "The minimum percentage of heap free after GC to avoid expansion."\
1445           " For most GCs this applies to the old generation. In G1 and"     \
1446           " ParallelGC it applies to the whole heap.")                      \
1447           range(0, 100)                                                     \
1448           constraint(MinHeapFreeRatioConstraintFunc,AfterErgo)              \
1449                                                                             \
1450   product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE,                          \
1451           "The maximum percentage of heap free after GC to avoid shrinking."\
1452           " For most GCs this applies to the old generation. In G1 and"     \
1453           " ParallelGC it applies to the whole heap.")                      \
1454           range(0, 100)                                                     \
1455           constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo)              \
1456                                                                             \
1457   product(bool, ShrinkHeapInSteps, true,                                    \
1458           "When disabled, informs the GC to shrink the java heap directly"  \
1459           " to the target size at the next full GC rather than requiring"   \
1460           " smaller steps during multiple full GCs.")                       \
1461                                                                             \
1462   product(intx, SoftRefLRUPolicyMSPerMB, 1000,                              \
1463           "Number of milliseconds per MB of free space in the heap")        \
1464           range(0, max_intx)                                                \
1465           constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1466                                                                             \
1467   product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K),               \
1468           "The minimum change in heap space due to GC (in bytes)")          \
1469           range(0, max_uintx)                                               \
1470                                                                             \
1471   product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K),           \
1472           "The minimum expansion of Metaspace (in bytes)")                  \
1473           range(0, max_uintx)                                               \
1474                                                                             \
1475   product(uintx, MaxMetaspaceFreeRatio,    70,                              \
1476           "The maximum percentage of Metaspace free after GC to avoid "     \
1477           "shrinking")                                                      \
1478           range(0, 100)                                                     \
1479           constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo)         \
1480                                                                             \
1481   product(uintx, MinMetaspaceFreeRatio,    40,                              \
1482           "The minimum percentage of Metaspace free after GC to avoid "     \
1483           "expansion")                                                      \
1484           range(0, 99)                                                      \
1485           constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo)         \
1486                                                                             \
1487   product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M),             \
1488           "The maximum expansion of Metaspace without full GC (in bytes)")  \
1489           range(0, max_uintx)                                               \
1490                                                                             \
1491   /* stack parameters */                                                    \
1492   product_pd(intx, StackYellowPages,                                        \
1493           "Number of yellow zone (recoverable overflows) pages of size "    \
1494           "4KB. If pages are bigger yellow zone is aligned up.")            \
1495           range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5))     \
1496                                                                             \
1497   product_pd(intx, StackRedPages,                                           \
1498           "Number of red zone (unrecoverable overflows) pages of size "     \
1499           "4KB. If pages are bigger red zone is aligned up.")               \
1500           range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2))           \
1501                                                                             \
1502   product_pd(intx, StackReservedPages,                                      \
1503           "Number of reserved zone (reserved to annotated methods) pages"   \
1504           " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1505           range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1506                                                                             \
1507   product(bool, RestrictReservedStack, true,                                \
1508           "Restrict @ReservedStackAccess to trusted classes")               \
1509                                                                             \
1510   /* greater stack shadow pages can't generate instruction to bang stack */ \
1511   product_pd(intx, StackShadowPages,                                        \
1512           "Number of shadow zone (for overflow checking) pages of size "    \
1513           "4KB. If pages are bigger shadow zone is aligned up. "            \
1514           "This should exceed the depth of the VM and native call stack.")  \
1515           range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30))    \
1516                                                                             \
1517   product_pd(intx, ThreadStackSize,                                         \
1518           "Thread Stack Size (in Kbytes)")                                  \
1519           range(0, 1 * M)                                                   \
1520                                                                             \
1521   product_pd(intx, VMThreadStackSize,                                       \
1522           "Non-Java Thread Stack Size (in Kbytes)")                         \
1523           range(0, max_intx/(1 * K))                                        \
1524                                                                             \
1525   product_pd(intx, CompilerThreadStackSize,                                 \
1526           "Compiler Thread Stack Size (in Kbytes)")                         \
1527           range(0, max_intx/(1 * K))                                        \
1528                                                                             \
1529   develop_pd(size_t, JVMInvokeMethodSlack,                                  \
1530           "Stack space (bytes) required for JVM_InvokeMethod to complete")  \
1531                                                                             \
1532   /* code cache parameters                                    */            \
1533   develop_pd(uintx, CodeCacheSegmentSize,                                   \
1534           "Code cache segment size (in bytes) - smallest unit of "          \
1535           "allocation")                                                     \
1536           range(1, 1024)                                                    \
1537           constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo)         \
1538                                                                             \
1539   develop_pd(intx, CodeEntryAlignment,                                      \
1540           "Code entry alignment for generated code (in bytes)")             \
1541           constraint(CodeEntryAlignmentConstraintFunc, AfterErgo)           \
1542                                                                             \
1543   product_pd(intx, OptoLoopAlignment,                                       \
1544           "Align inner loops to zero relative to this modulus")             \
1545           range(1, 16)                                                      \
1546           constraint(OptoLoopAlignmentConstraintFunc, AfterErgo)            \
1547                                                                             \
1548   product_pd(uintx, InitialCodeCacheSize,                                   \
1549           "Initial code cache size (in bytes)")                             \
1550           constraint(VMPageSizeConstraintFunc, AtParse)                     \
1551                                                                             \
1552   develop_pd(uintx, CodeCacheMinimumUseSpace,                               \
1553           "Minimum code cache size (in bytes) required to start VM.")       \
1554           range(0, max_uintx)                                               \
1555                                                                             \
1556   product(bool, SegmentedCodeCache, false,                                  \
1557           "Use a segmented code cache")                                     \
1558                                                                             \
1559   product_pd(uintx, ReservedCodeCacheSize,                                  \
1560           "Reserved code cache size (in bytes) - maximum code cache size")  \
1561           constraint(VMPageSizeConstraintFunc, AtParse)                     \
1562                                                                             \
1563   product_pd(uintx, NonProfiledCodeHeapSize,                                \
1564           "Size of code heap with non-profiled methods (in bytes)")         \
1565           range(0, max_uintx)                                               \
1566                                                                             \
1567   product_pd(uintx, ProfiledCodeHeapSize,                                   \
1568           "Size of code heap with profiled methods (in bytes)")             \
1569           range(0, max_uintx)                                               \
1570                                                                             \
1571   product_pd(uintx, NonNMethodCodeHeapSize,                                 \
1572           "Size of code heap with non-nmethods (in bytes)")                 \
1573           constraint(VMPageSizeConstraintFunc, AtParse)                     \
1574                                                                             \
1575   product_pd(uintx, CodeCacheExpansionSize,                                 \
1576           "Code cache expansion size (in bytes)")                           \
1577           range(32*K, max_uintx)                                            \
1578                                                                             \
1579   product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC,                    \
1580           "Minimum number of segments in a code cache block")               \
1581           range(1, 100)                                                     \
1582                                                                             \
1583   notproduct(bool, ExitOnFullCodeCache, false,                              \
1584           "Exit the VM if we fill the code cache")                          \
1585                                                                             \
1586   product(bool, UseCodeCacheFlushing, true,                                 \
1587           "Remove cold/old nmethods from the code cache")                   \
1588                                                                             \
1589   product(double, SweeperThreshold, 0.5,                                    \
1590           "Threshold controlling when code cache sweeper is invoked."       \
1591           "Value is percentage of ReservedCodeCacheSize.")                  \
1592           range(0.0, 100.0)                                                 \
1593                                                                             \
1594   product(uintx, StartAggressiveSweepingAt, 10,                             \
1595           "Start aggressive sweeping if X[%] of the code cache is free."    \
1596           "Segmented code cache: X[%] of the non-profiled heap."            \
1597           "Non-segmented code cache: X[%] of the total code cache")         \
1598           range(0, 100)                                                     \
1599                                                                             \
1600   /* interpreter debugging */                                               \
1601   develop(intx, BinarySwitchThreshold, 5,                                   \
1602           "Minimal number of lookupswitch entries for rewriting to binary " \
1603           "switch")                                                         \
1604                                                                             \
1605   develop(intx, StopInterpreterAt, 0,                                       \
1606           "Stop interpreter execution at specified bytecode number")        \
1607                                                                             \
1608   develop(intx, TraceBytecodesAt, 0,                                        \
1609           "Trace bytecodes starting with specified bytecode number")        \
1610                                                                             \
1611   /* Priorities */                                                          \
1612   product_pd(bool, UseThreadPriorities,  "Use native thread priorities")    \
1613                                                                             \
1614   product(intx, ThreadPriorityPolicy, 0,                                    \
1615           "0 : Normal.                                                     "\
1616           "    VM chooses priorities that are appropriate for normal       "\
1617           "    applications.                                               "\
1618           "    On Windows applications are allowed to use higher native    "\
1619           "    priorities. However, with ThreadPriorityPolicy=0, VM will   "\
1620           "    not use the highest possible native priority,               "\
1621           "    THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with     "\
1622           "    system threads. On Linux thread priorities are ignored      "\
1623           "    because the OS does not support static priority in          "\
1624           "    SCHED_OTHER scheduling class which is the only choice for   "\
1625           "    non-root, non-realtime applications.                        "\
1626           "1 : Aggressive.                                                 "\
1627           "    Java thread priorities map over to the entire range of      "\
1628           "    native thread priorities. Higher Java thread priorities map "\
1629           "    to higher native thread priorities. This policy should be   "\
1630           "    used with care, as sometimes it can cause performance       "\
1631           "    degradation in the application and/or the entire system. On "\
1632           "    Linux/BSD/macOS this policy requires root privilege or an   "\
1633           "    extended capability.")                                       \
1634           range(0, 1)                                                       \
1635                                                                             \
1636   product(bool, ThreadPriorityVerbose, false,                               \
1637           "Print priority changes")                                         \
1638                                                                             \
1639   product(intx, CompilerThreadPriority, -1,                                 \
1640           "The native priority at which compiler threads should run "       \
1641           "(-1 means no change)")                                           \
1642           range(min_jint, max_jint)                                         \
1643                                                                             \
1644   product(intx, VMThreadPriority, -1,                                       \
1645           "The native priority at which the VM thread should run "          \
1646           "(-1 means no change)")                                           \
1647           range(-1, 127)                                                    \
1648                                                                             \
1649   product(intx, JavaPriority1_To_OSPriority, -1,                            \
1650           "Map Java priorities to OS priorities")                           \
1651           range(-1, 127)                                                    \
1652                                                                             \
1653   product(intx, JavaPriority2_To_OSPriority, -1,                            \
1654           "Map Java priorities to OS priorities")                           \
1655           range(-1, 127)                                                    \
1656                                                                             \
1657   product(intx, JavaPriority3_To_OSPriority, -1,                            \
1658           "Map Java priorities to OS priorities")                           \
1659           range(-1, 127)                                                    \
1660                                                                             \
1661   product(intx, JavaPriority4_To_OSPriority, -1,                            \
1662           "Map Java priorities to OS priorities")                           \
1663           range(-1, 127)                                                    \
1664                                                                             \
1665   product(intx, JavaPriority5_To_OSPriority, -1,                            \
1666           "Map Java priorities to OS priorities")                           \
1667           range(-1, 127)                                                    \
1668                                                                             \
1669   product(intx, JavaPriority6_To_OSPriority, -1,                            \
1670           "Map Java priorities to OS priorities")                           \
1671           range(-1, 127)                                                    \
1672                                                                             \
1673   product(intx, JavaPriority7_To_OSPriority, -1,                            \
1674           "Map Java priorities to OS priorities")                           \
1675           range(-1, 127)                                                    \
1676                                                                             \
1677   product(intx, JavaPriority8_To_OSPriority, -1,                            \
1678           "Map Java priorities to OS priorities")                           \
1679           range(-1, 127)                                                    \
1680                                                                             \
1681   product(intx, JavaPriority9_To_OSPriority, -1,                            \
1682           "Map Java priorities to OS priorities")                           \
1683           range(-1, 127)                                                    \
1684                                                                             \
1685   product(intx, JavaPriority10_To_OSPriority,-1,                            \
1686           "Map Java priorities to OS priorities")                           \
1687           range(-1, 127)                                                    \
1688                                                                             \
1689   product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL,         \
1690           "Java thread priority 10 maps to critical scheduling priority")   \
1691                                                                             \
1692   product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL,     \
1693           "Compiler thread(s) run at critical scheduling priority")         \
1694                                                                             \
1695   develop(intx, NewCodeParameter,      0,                                   \
1696           "Testing Only: Create a dedicated integer parameter before "      \
1697           "putback")                                                        \
1698                                                                             \
1699   /* new oopmap storage allocation */                                       \
1700   develop(intx, MinOopMapAllocation,     8,                                 \
1701           "Minimum number of OopMap entries in an OopMapSet")               \
1702                                                                             \
1703   /* recompilation */                                                       \
1704   product_pd(intx, CompileThreshold,                                        \
1705           "number of interpreted method invocations before (re-)compiling") \
1706           constraint(CompileThresholdConstraintFunc, AfterErgo)             \
1707                                                                             \
1708   product_pd(bool, TieredCompilation,                                       \
1709           "Enable tiered compilation")                                      \
1710                                                                             \
1711   /* Properties for Java libraries  */                                      \
1712                                                                             \
1713   product(uint64_t, MaxDirectMemorySize, 0,                                 \
1714           "Maximum total size of NIO direct-buffer allocations")            \
1715           range(0, max_jlong)                                               \
1716                                                                             \
1717   /* Flags used for temporary code during development  */                   \
1718                                                                             \
1719   product(bool, UseNewCode, false, DIAGNOSTIC,                              \
1720           "Testing Only: Use the new version while testing")                \
1721                                                                             \
1722   product(bool, UseNewCode2, false, DIAGNOSTIC,                             \
1723           "Testing Only: Use the new version while testing")                \
1724                                                                             \
1725   product(bool, UseNewCode3, false, DIAGNOSTIC,                             \
1726           "Testing Only: Use the new version while testing")                \
1727                                                                             \
1728   notproduct(bool, UseDebuggerErgo, false,                                  \
1729           "Debugging Only: Adjust the VM to be more debugger-friendly. "    \
1730           "Turns on the other UseDebuggerErgo* flags")                      \
1731                                                                             \
1732   notproduct(bool, UseDebuggerErgo1, false,                                 \
1733           "Debugging Only: Enable workarounds for debugger induced "        \
1734           "os::processor_id() >= os::processor_count() problems")           \
1735                                                                             \
1736   notproduct(bool, UseDebuggerErgo2, false,                                 \
1737           "Debugging Only: Limit the number of spawned JVM threads")        \
1738                                                                             \
1739   notproduct(bool, EnableJVMTIStackDepthAsserts, true,                      \
1740           "Enable JVMTI asserts related to stack depth checks")             \
1741                                                                             \
1742   /* flags for performance data collection */                               \
1743                                                                             \
1744   product(bool, UsePerfData, true,                                          \
1745           "Flag to disable jvmstat instrumentation for performance testing "\
1746           "and problem isolation purposes")                                 \
1747                                                                             \
1748   product(bool, PerfDataSaveToFile, false,                                  \
1749           "Save PerfData memory to hsperfdata_<pid> file on exit")          \
1750                                                                             \
1751   product(ccstr, PerfDataSaveFile, NULL,                                    \
1752           "Save PerfData memory to the specified absolute pathname. "       \
1753           "The string %p in the file name (if present) "                    \
1754           "will be replaced by pid")                                        \
1755                                                                             \
1756   product(intx, PerfDataSamplingInterval, 50,                               \
1757           "Data sampling interval (in milliseconds)")                       \
1758           range(PeriodicTask::min_interval, max_jint)                       \
1759           constraint(PerfDataSamplingIntervalFunc, AfterErgo)               \
1760                                                                             \
1761   product(bool, PerfDisableSharedMem, false,                                \
1762           "Store performance data in standard memory")                      \
1763                                                                             \
1764   product(intx, PerfDataMemorySize, 32*K,                                   \
1765           "Size of performance data memory region. Will be rounded "        \
1766           "up to a multiple of the native os page size.")                   \
1767           range(128, 32*64*K)                                               \
1768                                                                             \
1769   product(intx, PerfMaxStringConstLength, 1024,                             \
1770           "Maximum PerfStringConstant string length before truncation")     \
1771           range(32, 32*K)                                                   \
1772                                                                             \
1773   product(bool, PerfAllowAtExitRegistration, false,                         \
1774           "Allow registration of atexit() methods")                         \
1775                                                                             \
1776   product(bool, PerfBypassFileSystemCheck, false,                           \
1777           "Bypass Win32 file system criteria checks (Windows Only)")        \
1778                                                                             \
1779   product(intx, UnguardOnExecutionViolation, 0,                             \
1780           "Unguard page and retry on no-execute fault (Win32 only) "        \
1781           "0=off, 1=conservative, 2=aggressive")                            \
1782           range(0, 2)                                                       \
1783                                                                             \
1784   /* Serviceability Support */                                              \
1785                                                                             \
1786   product(bool, ManagementServer, false,                                    \
1787           "Create JMX Management Server")                                   \
1788                                                                             \
1789   product(bool, DisableAttachMechanism, false,                              \
1790           "Disable mechanism that allows tools to attach to this VM")       \
1791                                                                             \
1792   product(bool, StartAttachListener, false,                                 \
1793           "Always start Attach Listener at VM startup")                     \
1794                                                                             \
1795   product(bool, EnableDynamicAgentLoading, true,                            \
1796           "Allow tools to load agents with the attach mechanism")           \
1797                                                                             \
1798   product(bool, PrintConcurrentLocks, false, MANAGEABLE,                    \
1799           "Print java.util.concurrent locks in thread dump")                \
1800                                                                             \
1801   /* Shared spaces */                                                       \
1802                                                                             \
1803   product(bool, UseSharedSpaces, true,                                      \
1804           "(Deprecated) Use shared spaces for metadata")                    \
1805                                                                             \
1806   product(bool, VerifySharedSpaces, false,                                  \
1807           "Verify integrity of shared spaces")                              \
1808                                                                             \
1809   product(bool, RequireSharedSpaces, false,                                 \
1810           "(Deprecated) Require shared spaces for metadata")                \
1811                                                                             \
1812   product(bool, DumpSharedSpaces, false,                                    \
1813           "(Deprecated) Special mode: JVM reads a class list, loads "       \
1814           "classes, builds shared spaces, and dumps the shared spaces to "  \
1815           "a file to be used in future JVM runs")                           \
1816                                                                             \
1817   product(bool, DynamicDumpSharedSpaces, false,                             \
1818           "(Deprecated) Dynamic archive")                                   \
1819                                                                             \
1820   product(bool, RecordDynamicDumpInfo, false,                               \
1821           "Record class info for jcmd VM.cds dynamic_dump")                 \
1822                                                                             \
1823   product(bool, PrintSharedArchiveAndExit, false,                           \
1824           "Print shared archive file contents")                             \
1825                                                                             \
1826   product(bool, PrintSharedDictionary, false,                               \
1827           "If PrintSharedArchiveAndExit is true, also print the shared "    \
1828           "dictionary")                                                     \
1829                                                                             \
1830   product(size_t, SharedBaseAddress, LP64_ONLY(32*G)                        \
1831           NOT_LP64(LINUX_ONLY(2*G) NOT_LINUX(0)),                           \
1832           "Address to allocate shared memory region for class data")        \
1833           range(0, SIZE_MAX)                                                \
1834                                                                             \
1835   product(ccstr, SharedArchiveConfigFile, NULL,                             \
1836           "Data to add to the CDS archive file")                            \
1837                                                                             \
1838   product(uintx, SharedSymbolTableBucketSize, 4,                            \
1839           "Average number of symbols per bucket in shared table")           \
1840           range(2, 246)                                                     \
1841                                                                             \
1842   product(bool, AllowArchivingWithJavaAgent, false, DIAGNOSTIC,             \
1843           "Allow Java agent to be run with CDS dumping")                    \
1844                                                                             \
1845   product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC,                  \
1846           "Print generated stub code for method handles")                   \
1847                                                                             \
1848   product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC,               \
1849           "perform extra checks when constructing method handles")          \
1850                                                                             \
1851   product(bool, ShowHiddenFrames, false, DIAGNOSTIC,                        \
1852           "show method handle implementation frames (usually hidden)")      \
1853                                                                             \
1854   product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL,             \
1855           "trust final non-static declarations for constant folding")       \
1856                                                                             \
1857   product(bool, FoldStableValues, true, DIAGNOSTIC,                         \
1858           "Optimize loads from stable fields (marked w/ @Stable)")          \
1859                                                                             \
1860   product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC,                         \
1861           "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1862           "resolved before the bootstrap method is called; 1: when a BSM "  \
1863           "that may accept a BootstrapCallInfo is detected, use that API "  \
1864           "to pass BSM arguments, which allows the BSM to delay their "     \
1865           "resolution; 2+: stress test the BCI API by calling more BSMs "   \
1866           "via that API, instead of with the eagerly-resolved array.")      \
1867                                                                             \
1868   product(bool, PauseAtStartup,      false, DIAGNOSTIC,                     \
1869           "Causes the VM to pause at startup time and wait for the pause "  \
1870           "file to be removed (default: ./vm.paused.<pid>)")                \
1871                                                                             \
1872   product(ccstr, PauseAtStartupFile, NULL, DIAGNOSTIC,                      \
1873           "The file to create and for whose removal to await when pausing " \
1874           "at startup. (default: ./vm.paused.<pid>)")                       \
1875                                                                             \
1876   product(bool, PauseAtExit, false, DIAGNOSTIC,                             \
1877           "Pause and wait for keypress on exit if a debugger is attached")  \
1878                                                                             \
1879   product(bool, ExtendedDTraceProbes,    false,                             \
1880           "Enable performance-impacting dtrace probes")                     \
1881                                                                             \
1882   product(bool, DTraceMethodProbes, false,                                  \
1883           "Enable dtrace probes for method-entry and method-exit")          \
1884                                                                             \
1885   product(bool, DTraceAllocProbes, false,                                   \
1886           "Enable dtrace probes for object allocation")                     \
1887                                                                             \
1888   product(bool, DTraceMonitorProbes, false,                                 \
1889           "Enable dtrace probes for monitor events")                        \
1890                                                                             \
1891   product(bool, RelaxAccessControlCheck, false,                             \
1892           "Relax the access control checks in the verifier")                \
1893                                                                             \
1894   product(uintx, StringTableSize, defaultStringTableSize,                   \
1895           "Number of buckets in the interned String table "                 \
1896           "(will be rounded to nearest higher power of 2)")                 \
1897           range(minimumStringTableSize, 16777216ul /* 2^24 */)              \
1898                                                                             \
1899   product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL,     \
1900           "Number of buckets in the JVM internal Symbol table")             \
1901           range(minimumSymbolTableSize, 16777216ul /* 2^24 */)              \
1902                                                                             \
1903   product(bool, UseStringDeduplication, false,                              \
1904           "Use string deduplication")                                       \
1905                                                                             \
1906   product(uint, StringDeduplicationAgeThreshold, 3,                         \
1907           "A string must reach this age (or be promoted to an old region) " \
1908           "to be considered for deduplication")                             \
1909           range(1, markWord::max_age)                                       \
1910                                                                             \
1911   product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL,   \
1912           "Approximate initial number of buckets in the table")             \
1913           range(1, 1 * G)                                                   \
1914                                                                             \
1915   product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL,     \
1916           "Entries per bucket above which the table should be expanded")    \
1917           range(0.1, 1000.0)                                                \
1918                                                                             \
1919   product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL,    \
1920           "Entries per bucket below which the table should be shrunk")      \
1921           range(0.01, 100.0)                                                \
1922                                                                             \
1923   product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL,    \
1924           "Desired entries per bucket when resizing the table")             \
1925           range(0.01, 1000.0)                                               \
1926                                                                             \
1927   product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1928           "Minimum number of dead table entries for cleaning the table")    \
1929                                                                             \
1930   product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL,      \
1931           "Minimum percentage of dead table entries for cleaning the table") \
1932           range(1, 100)                                                     \
1933                                                                             \
1934   product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC,           \
1935           "Force more frequent table resizing")                             \
1936                                                                             \
1937   product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC,             \
1938           "Seed for the table hashing function; 0 requests computed seed")  \
1939                                                                             \
1940   product(bool, WhiteBoxAPI, false, DIAGNOSTIC,                             \
1941           "Enable internal testing APIs")                                   \
1942                                                                             \
1943   product(ccstr, DumpLoadedClassList, NULL,                                 \
1944           "Dump the names all loaded classes, that could be stored into "   \
1945           "the CDS archive, in the specified file")                         \
1946                                                                             \
1947   product(ccstr, SharedClassListFile, NULL,                                 \
1948           "Override the default CDS class list")                            \
1949                                                                             \
1950   product(ccstr, SharedArchiveFile, NULL,                                   \
1951           "Override the default location of the CDS archive file")          \
1952                                                                             \
1953   product(ccstr, ArchiveClassesAtExit, NULL,                                \
1954           "The path and name of the dynamic archive file")                  \
1955                                                                             \
1956   product(ccstr, ExtraSharedClassListFile, NULL,                            \
1957           "Extra classlist for building the CDS archive file")              \
1958                                                                             \
1959   product(intx, ArchiveRelocationMode, 0, DIAGNOSTIC,                       \
1960            "(0) first map at preferred address, and if "                    \
1961            "unsuccessful, map at alternative address (default); "           \
1962            "(1) always map at alternative address; "                        \
1963            "(2) always map at preferred address, and if unsuccessful, "     \
1964            "do not map the archive")                                        \
1965            range(0, 2)                                                      \
1966                                                                             \
1967   product(size_t, ArrayAllocatorMallocLimit, (size_t)-1, EXPERIMENTAL,      \
1968           "Allocation less than this value will be allocated "              \
1969           "using malloc. Larger allocations will use mmap.")                \
1970                                                                             \
1971   product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL,                  \
1972           "Accesses to all variables should always be atomic")              \
1973                                                                             \
1974   product(bool, UseUnalignedAccesses, false, DIAGNOSTIC,                    \
1975           "Use unaligned memory accesses in Unsafe")                        \
1976                                                                             \
1977   product_pd(bool, PreserveFramePointer,                                    \
1978              "Use the FP register for holding the frame pointer "           \
1979              "and not as a general purpose register.")                      \
1980                                                                             \
1981   product(size_t, AsyncLogBufferSize, 2*M,                                  \
1982           "Memory budget (in bytes) for the buffer of Asynchronous "        \
1983           "Logging (-Xlog:async).")                                         \
1984           range(100*K, 50*M)                                                \
1985                                                                             \
1986   product(bool, CheckIntrinsics, true, DIAGNOSTIC,                          \
1987              "When a class C is loaded, check that "                        \
1988              "(1) all intrinsics defined by the VM for class C are present "\
1989              "in the loaded class file and are marked with the "            \
1990              "@IntrinsicCandidate annotation, that "                        \
1991              "(2) there is an intrinsic registered for all loaded methods " \
1992              "that are annotated with the @IntrinsicCandidate annotation, " \
1993              "and that "                                                    \
1994              "(3) no orphan methods exist for class C (i.e., methods for "  \
1995              "which the VM declares an intrinsic but that are not declared "\
1996              "in the loaded class C. "                                      \
1997              "Check (3) is available only in debug builds.")                \
1998                                                                             \
1999   product_pd(intx, InitArrayShortSize, DIAGNOSTIC,                          \
2000           "Threshold small size (in bytes) for clearing arrays. "           \
2001           "Anything this size or smaller may get converted to discrete "    \
2002           "scalar stores.")                                                 \
2003           range(0, max_intx)                                                \
2004           constraint(InitArrayShortSizeConstraintFunc, AfterErgo)           \
2005                                                                             \
2006   product(ccstr, AllocateHeapAt, NULL,                                      \
2007           "Path to the directory where a temporary file will be created "   \
2008           "to use as the backing store for Java Heap.")                     \
2009                                                                             \
2010   develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0),       \
2011                "Run periodic metaspace verifications (0 - none, "           \
2012                "1 - always, >1 every nth interval)")                        \
2013                                                                             \
2014   product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC,                    \
2015           "On internal errors, include registers in error report.")         \
2016                                                                             \
2017   product(bool, UseSwitchProfiling, true, DIAGNOSTIC,                       \
2018           "leverage profiling for table/lookup switch")                     \
2019                                                                             \
2020   develop(bool, TraceMemoryWriteback, false,                                \
2021           "Trace memory writeback operations")                              \
2022                                                                             \
2023   JFR_ONLY(product(bool, FlightRecorder, false,                             \
2024           "(Deprecated) Enable Flight Recorder"))                           \
2025                                                                             \
2026   JFR_ONLY(product(ccstr, FlightRecorderOptions, NULL,                      \
2027           "Flight Recorder options"))                                       \
2028                                                                             \
2029   JFR_ONLY(product(ccstr, StartFlightRecording, NULL,                       \
2030           "Start flight recording with options"))                           \
2031                                                                             \
2032   product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL,            \
2033           "Use platform unstable time where supported for timestamps only") \
2034                                                                             \
2035   product(bool, UseEmptySlotsInSupers, true,                                \
2036                 "Allow allocating fields in empty slots of super-classes")  \
2037                                                                             \
2038   product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC,           \
2039                 "Make nmethod barriers deoptimise a lot.")                  \
2040                                                                             \
2041   develop(bool, VerifyCrossModifyFence,                                     \
2042           false AARCH64_ONLY(DEBUG_ONLY(||true)),                           \
2043              "Mark all threads after a safepoint, and clear on a modify "   \
2044              "fence. Add cleanliness checks.")                              \
2045                                                                             \
2046   develop(bool, TraceOptimizedUpcallStubs, false,                              \
2047                 "Trace optimized upcall stub generation")                      \
2048                                                                             \
2049   develop(bool, TraceNativeInvokers, false,                                 \
2050                 "Trace Panama native invoker generation")                   \
2051 
2052 // end of RUNTIME_FLAGS
2053 
2054 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2055 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2056 DECLARE_FLAGS(RUNTIME_FLAGS)
2057 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2058 
2059 #endif // SHARE_RUNTIME_GLOBALS_HPP