1 /*
   2  * Copyright (c) 1997, 2020, 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.hpp"
  29 #include "gc/shared/gc_globals.hpp"
  30 #include "runtime/globals_shared.hpp"
  31 #include "utilities/align.hpp"
  32 #include "utilities/globalDefinitions.hpp"
  33 #include "utilities/macros.hpp"
  34 #include CPU_HEADER(globals)
  35 #include OS_HEADER(globals)
  36 #include OS_CPU_HEADER(globals)
  37 
  38 // develop flags are settable / visible only during development and are constant in the PRODUCT version
  39 // product flags are always settable / visible
  40 // notproduct flags are settable / visible only during development and are not declared in the PRODUCT version
  41 
  42 // A flag must be declared with one of the following types:
  43 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t.
  44 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used
  45 // only in this file, because the macrology requires single-token type names.
  46 
  47 // Note: Diagnostic options not meant for VM tuning or for product modes.
  48 // They are to be used for VM quality assurance or field diagnosis
  49 // of VM bugs.  They are hidden so that users will not be encouraged to
  50 // try them as if they were VM ordinary execution options.  However, they
  51 // are available in the product version of the VM.  Under instruction
  52 // from support engineers, VM customers can turn them on to collect
  53 // diagnostic information about VM problems.  To use a VM diagnostic
  54 // option, you must first specify +UnlockDiagnosticVMOptions.
  55 // (This master switch also affects the behavior of -Xprintflags.)
  56 //
  57 // experimental flags are in support of features that are not
  58 //    part of the officially supported product, but are available
  59 //    for experimenting with. They could, for example, be performance
  60 //    features that may not have undergone full or rigorous QA, but which may
  61 //    help performance in some cases and released for experimentation
  62 //    by the community of users and developers. This flag also allows one to
  63 //    be able to build a fully supported product that nonetheless also
  64 //    ships with some unsupported, lightly tested, experimental features.
  65 //    Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
  66 //    UnlockExperimentalVMOptions flag, which allows the control and
  67 //    modification of the experimental flags.
  68 //
  69 // Nota bene: neither diagnostic nor experimental options should be used casually,
  70 //    and they are not supported on production loads, except under explicit
  71 //    direction from support engineers.
  72 //
  73 // manageable flags are writeable external product flags.
  74 //    They are dynamically writeable through the JDK management interface
  75 //    (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole.
  76 //    These flags are external exported interface (see CCC).  The list of
  77 //    manageable flags can be queried programmatically through the management
  78 //    interface.
  79 //
  80 //    A flag can be made as "manageable" only if
  81 //    - the flag is defined in a CCC as an external exported interface.
  82 //    - the VM implementation supports dynamic setting of the flag.
  83 //      This implies that the VM must *always* query the flag variable
  84 //      and not reuse state related to the flag state at any given time.
  85 //    - you want the flag to be queried programmatically by the customers.
  86 //
  87 // product_rw flags are writeable internal product flags.
  88 //    They are like "manageable" flags but for internal/private use.
  89 //    The list of product_rw flags are internal/private flags which
  90 //    may be changed/removed in a future release.  It can be set
  91 //    through the management interface to get/set value
  92 //    when the name of flag is supplied.
  93 //
  94 //    A flag can be made as "product_rw" only if
  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 //
  99 // Note that when there is a need to support develop flags to be writeable,
 100 // it can be done in the same way as product_rw.
 101 //
 102 // range is a macro that will expand to min and max arguments for range
 103 //    checking code if provided - see jvmFlagRangeList.hpp
 104 //
 105 // constraint is a macro that will expand to custom function call
 106 //    for constraint checking if provided - see jvmFlagConstraintList.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 #define RUNTIME_FLAGS(develop, \
 116                       develop_pd, \
 117                       product, \
 118                       product_pd, \
 119                       diagnostic, \
 120                       diagnostic_pd, \
 121                       experimental, \
 122                       notproduct, \
 123                       manageable, \
 124                       product_rw, \
 125                       lp64_product, \
 126                       range, \
 127                       constraint) \
 128                                                                             \
 129   lp64_product(bool, UseCompressedOops, false,                              \
 130           "Use 32-bit object references in 64-bit VM. "                     \
 131           "lp64_product means flag is always constant in 32 bit VM")        \
 132                                                                             \
 133   lp64_product(bool, UseCompressedClassPointers, false,                     \
 134           "Use 32-bit class pointers in 64-bit VM. "                        \
 135           "lp64_product means flag is always constant in 32 bit VM")        \
 136                                                                             \
 137   notproduct(bool, CheckCompressedOops, true,                               \
 138           "Generate checks in encoding/decoding code in debug VM")          \
 139                                                                             \
 140   product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17),                        \
 141           "Heap allocation steps through preferred address regions to find" \
 142           " where it can allocate the heap. Number of steps to take per "   \
 143           "region.")                                                        \
 144           range(1, max_uintx)                                               \
 145                                                                             \
 146   lp64_product(intx, ObjectAlignmentInBytes, 8,                             \
 147           "Default object alignment in bytes, 8 is minimum")                \
 148           range(8, 256)                                                     \
 149           constraint(ObjectAlignmentInBytesConstraintFunc,AtParse)          \
 150                                                                             \
 151   develop(bool, CleanChunkPoolAsync, true,                                  \
 152           "Clean the chunk pool asynchronously")                            \
 153                                                                             \
 154   diagnostic(uint, HandshakeTimeout, 0,                                     \
 155           "If nonzero set a timeout in milliseconds for handshakes")        \
 156                                                                             \
 157   experimental(bool, AlwaysSafeConstructors, false,                         \
 158           "Force safe construction, as if all fields are final.")           \
 159                                                                             \
 160   diagnostic(bool, UnlockDiagnosticVMOptions, trueInDebug,                  \
 161           "Enable normal processing of flags relating to field diagnostics")\
 162                                                                             \
 163   experimental(bool, UnlockExperimentalVMOptions, false,                    \
 164           "Enable normal processing of flags relating to experimental "     \
 165           "features")                                                       \
 166                                                                             \
 167   product(bool, JavaMonitorsInStackTrace, true,                             \
 168           "Print information about Java monitor locks when the stacks are"  \
 169           "dumped")                                                         \
 170                                                                             \
 171   product_pd(bool, UseLargePages,                                           \
 172           "Use large page memory")                                          \
 173                                                                             \
 174   product_pd(bool, UseLargePagesIndividualAllocation,                       \
 175           "Allocate large pages individually for better affinity")          \
 176                                                                             \
 177   develop(bool, LargePagesIndividualAllocationInjectError, false,           \
 178           "Fail large pages individual allocation")                         \
 179                                                                             \
 180   product(bool, UseLargePagesInMetaspace, false,                            \
 181           "Use large page memory in metaspace. "                            \
 182           "Only used if UseLargePages is enabled.")                         \
 183                                                                             \
 184   product(bool, UseNUMA, false,                                             \
 185           "Use NUMA if available")                                          \
 186                                                                             \
 187   product(bool, UseNUMAInterleaving, false,                                 \
 188           "Interleave memory across NUMA nodes if available")               \
 189                                                                             \
 190   product(size_t, NUMAInterleaveGranularity, 2*M,                           \
 191           "Granularity to use for NUMA interleaving on Windows OS")         \
 192           range(os::vm_allocation_granularity(), NOT_LP64(2*G) LP64_ONLY(8192*G)) \
 193                                                                             \
 194   product(bool, ForceNUMA, false,                                           \
 195           "(Deprecated) Force NUMA optimizations on single-node/UMA systems") \
 196                                                                             \
 197   product(uintx, NUMAChunkResizeWeight, 20,                                 \
 198           "Percentage (0-100) used to weight the current sample when "      \
 199           "computing exponentially decaying average for "                   \
 200           "AdaptiveNUMAChunkSizing")                                        \
 201           range(0, 100)                                                     \
 202                                                                             \
 203   product(size_t, NUMASpaceResizeRate, 1*G,                                 \
 204           "Do not reallocate more than this amount per collection")         \
 205           range(0, max_uintx)                                               \
 206                                                                             \
 207   product(bool, UseAdaptiveNUMAChunkSizing, true,                           \
 208           "Enable adaptive chunk sizing for NUMA")                          \
 209                                                                             \
 210   product(bool, NUMAStats, false,                                           \
 211           "Print NUMA stats in detailed heap information")                  \
 212                                                                             \
 213   product(uintx, NUMAPageScanRate, 256,                                     \
 214           "Maximum number of pages to include in the page scan procedure")  \
 215           range(0, max_uintx)                                               \
 216                                                                             \
 217   product(bool, UseAES, false,                                              \
 218           "Control whether AES instructions are used when available")       \
 219                                                                             \
 220   product(bool, UseFMA, false,                                              \
 221           "Control whether FMA instructions are used when available")       \
 222                                                                             \
 223   product(bool, UseSHA, false,                                              \
 224           "Control whether SHA instructions are used when available")       \
 225                                                                             \
 226   diagnostic(bool, UseGHASHIntrinsics, false,                               \
 227           "Use intrinsics for GHASH versions of crypto")                    \
 228                                                                             \
 229   product(bool, UseBASE64Intrinsics, false,                                 \
 230           "Use intrinsics for java.util.Base64")                            \
 231                                                                             \
 232   product(size_t, LargePageSizeInBytes, 0,                                  \
 233           "Large page size (0 to let VM choose the page size)")             \
 234           range(0, max_uintx)                                               \
 235                                                                             \
 236   product(size_t, LargePageHeapSizeThreshold, 128*M,                        \
 237           "Use large pages if maximum heap is at least this big")           \
 238           range(0, max_uintx)                                               \
 239                                                                             \
 240   product(bool, ForceTimeHighResolution, false,                             \
 241           "Using high time resolution (for Win32 only)")                    \
 242                                                                             \
 243   develop(bool, TracePcPatching, false,                                     \
 244           "Trace usage of frame::patch_pc")                                 \
 245                                                                             \
 246   develop(bool, TraceRelocator, false,                                      \
 247           "Trace the bytecode relocator")                                   \
 248                                                                             \
 249   develop(bool, TraceLongCompiles, false,                                   \
 250           "Print out every time compilation is longer than "                \
 251           "a given threshold")                                              \
 252                                                                             \
 253   diagnostic(bool, SafepointALot, false,                                    \
 254           "Generate a lot of safepoints. This works with "                  \
 255           "GuaranteedSafepointInterval")                                    \
 256                                                                             \
 257   diagnostic(bool, HandshakeALot, false,                                    \
 258           "Generate a lot of handshakes. This works with "                  \
 259           "GuaranteedSafepointInterval")                                    \
 260                                                                             \
 261   product_pd(bool, BackgroundCompilation,                                   \
 262           "A thread requesting compilation is not blocked during "          \
 263           "compilation")                                                    \
 264                                                                             \
 265   product(bool, PrintVMQWaitTime, false,                                    \
 266           "(Deprecated) Print out the waiting time in VM operation queue")  \
 267                                                                             \
 268   product(bool, MethodFlushing, true,                                       \
 269           "Reclamation of zombie and not-entrant methods")                  \
 270                                                                             \
 271   develop(bool, VerifyStack, false,                                         \
 272           "Verify stack of each thread when it is entering a runtime call") \
 273                                                                             \
 274   diagnostic(bool, ForceUnreachable, false,                                 \
 275           "Make all non code cache addresses to be unreachable by "         \
 276           "forcing use of 64bit literal fixups")                            \
 277                                                                             \
 278   notproduct(bool, StressDerivedPointers, false,                            \
 279           "Force scavenge when a derived pointer is detected on stack "     \
 280           "after rtm call")                                                 \
 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   diagnostic(bool, InlineArrayCopy, true,                                   \
 295           "Inline arraycopy native that is known to be part of "            \
 296           "base library DLL")                                               \
 297                                                                             \
 298   diagnostic(bool, InlineObjectHash, true,                                  \
 299           "Inline Object::hashCode() native that is known to be part "      \
 300           "of base library DLL")                                            \
 301                                                                             \
 302   diagnostic(bool, InlineNatives, true,                                     \
 303           "Inline natives that are known to be part of base library DLL")   \
 304                                                                             \
 305   diagnostic(bool, InlineMathNatives, true,                                 \
 306           "Inline SinD, CosD, etc.")                                        \
 307                                                                             \
 308   diagnostic(bool, InlineClassNatives, true,                                \
 309           "Inline Class.isInstance, etc")                                   \
 310                                                                             \
 311   diagnostic(bool, InlineThreadNatives, true,                               \
 312           "Inline Thread.currentThread, etc")                               \
 313                                                                             \
 314   diagnostic(bool, InlineUnsafeOps, true,                                   \
 315           "Inline memory ops (native methods) from Unsafe")                 \
 316                                                                             \
 317   product(bool, CriticalJNINatives, true,                                   \
 318           "Check for critical JNI entry points")                            \
 319                                                                             \
 320   notproduct(bool, StressCriticalJNINatives, false,                         \
 321           "Exercise register saving code in critical natives")              \
 322                                                                             \
 323   diagnostic(bool, UseAESIntrinsics, false,                                 \
 324           "Use intrinsics for AES versions of crypto")                      \
 325                                                                             \
 326   diagnostic(bool, UseAESCTRIntrinsics, false,                              \
 327           "Use intrinsics for the paralleled version of AES/CTR crypto")    \
 328                                                                             \
 329   diagnostic(bool, UseSHA1Intrinsics, false,                                \
 330           "Use intrinsics for SHA-1 crypto hash function. "                 \
 331           "Requires that UseSHA is enabled.")                               \
 332                                                                             \
 333   diagnostic(bool, UseSHA256Intrinsics, false,                              \
 334           "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. "  \
 335           "Requires that UseSHA is enabled.")                               \
 336                                                                             \
 337   diagnostic(bool, UseSHA512Intrinsics, false,                              \
 338           "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. "  \
 339           "Requires that UseSHA is enabled.")                               \
 340                                                                             \
 341   diagnostic(bool, UseCRC32Intrinsics, false,                               \
 342           "use intrinsics for java.util.zip.CRC32")                         \
 343                                                                             \
 344   diagnostic(bool, UseCRC32CIntrinsics, false,                              \
 345           "use intrinsics for java.util.zip.CRC32C")                        \
 346                                                                             \
 347   diagnostic(bool, UseAdler32Intrinsics, false,                             \
 348           "use intrinsics for java.util.zip.Adler32")                       \
 349                                                                             \
 350   diagnostic(bool, UseVectorizedMismatchIntrinsic, false,                   \
 351           "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
 352                                                                             \
 353   diagnostic(ccstrlist, DisableIntrinsic, "",                               \
 354          "do not expand intrinsics whose (internal) names appear here")     \
 355                                                                             \
 356   develop(bool, TraceCallFixup, false,                                      \
 357           "Trace all call fixups")                                          \
 358                                                                             \
 359   develop(bool, DeoptimizeALot, false,                                      \
 360           "Deoptimize at every exit from the runtime system")               \
 361                                                                             \
 362   notproduct(ccstrlist, DeoptimizeOnlyAt, "",                               \
 363           "A comma separated list of bcis to deoptimize at")                \
 364                                                                             \
 365   develop(bool, DeoptimizeRandom, false,                                    \
 366           "Deoptimize random frames on random exit from the runtime system")\
 367                                                                             \
 368   notproduct(bool, ZombieALot, false,                                       \
 369           "Create zombies (non-entrant) at exit from the runtime system")   \
 370                                                                             \
 371   notproduct(bool, WalkStackALot, false,                                    \
 372           "Trace stack (no print) at every exit from the runtime system")   \
 373                                                                             \
 374   product(bool, Debugging, false,                                           \
 375           "Set when executing debug methods in debug.cpp "                  \
 376           "(to prevent triggering assertions)")                             \
 377                                                                             \
 378   notproduct(bool, VerifyLastFrame, false,                                  \
 379           "Verify oops on last frame on entry to VM")                       \
 380                                                                             \
 381   product(bool, SafepointTimeout, false,                                    \
 382           "Time out and warn or fail after SafepointTimeoutDelay "          \
 383           "milliseconds if failed to reach safepoint")                      \
 384                                                                             \
 385   diagnostic(bool, AbortVMOnSafepointTimeout, false,                        \
 386           "Abort upon failure to reach safepoint (see SafepointTimeout)")   \
 387                                                                             \
 388   diagnostic(bool, AbortVMOnVMOperationTimeout, false,                      \
 389           "Abort upon failure to complete VM operation promptly")           \
 390                                                                             \
 391   diagnostic(intx, AbortVMOnVMOperationTimeoutDelay, 1000,                  \
 392           "Delay in milliseconds for option AbortVMOnVMOperationTimeout")   \
 393           range(0, max_intx)                                                \
 394                                                                             \
 395   /* 50 retries * (5 * current_retry_count) millis = ~6.375 seconds */      \
 396   /* typically, at most a few retries are needed                    */      \
 397   product(intx, SuspendRetryCount, 50,                                      \
 398           "Maximum retry count for an external suspend request")            \
 399           range(0, max_intx)                                                \
 400                                                                             \
 401   product(intx, SuspendRetryDelay, 5,                                       \
 402           "Milliseconds to delay per retry (* current_retry_count)")        \
 403           range(0, max_intx)                                                \
 404                                                                             \
 405   product(bool, AssertOnSuspendWaitFailure, false,                          \
 406           "Assert/Guarantee on external suspend wait failure")              \
 407                                                                             \
 408   product(bool, TraceSuspendWaitFailures, false,                            \
 409           "Trace external suspend wait failures")                           \
 410                                                                             \
 411   product(bool, MaxFDLimit, true,                                           \
 412           "Bump the number of file descriptors to maximum (Unix only)")     \
 413                                                                             \
 414   diagnostic(bool, LogEvents, true,                                         \
 415           "Enable the various ring buffer event logs")                      \
 416                                                                             \
 417   diagnostic(uintx, LogEventsBufferEntries, 20,                             \
 418           "Number of ring buffer event logs")                               \
 419           range(1, NOT_LP64(1*K) LP64_ONLY(1*M))                            \
 420                                                                             \
 421   diagnostic(bool, BytecodeVerificationRemote, true,                        \
 422           "Enable the Java bytecode verifier for remote classes")           \
 423                                                                             \
 424   diagnostic(bool, BytecodeVerificationLocal, false,                        \
 425           "Enable the Java bytecode verifier for local classes")            \
 426                                                                             \
 427   develop(bool, ForceFloatExceptions, trueInDebug,                          \
 428           "Force exceptions on FP stack under/overflow")                    \
 429                                                                             \
 430   develop(bool, VerifyStackAtCalls, false,                                  \
 431           "Verify that the stack pointer is unchanged after calls")         \
 432                                                                             \
 433   develop(bool, TraceJavaAssertions, false,                                 \
 434           "Trace java language assertions")                                 \
 435                                                                             \
 436   notproduct(bool, VerifyCodeCache, false,                                  \
 437           "Verify code cache on memory allocation/deallocation")            \
 438                                                                             \
 439   develop(bool, UseMallocOnly, false,                                       \
 440           "Use only malloc/free for allocation (no resource area/arena)")   \
 441                                                                             \
 442   develop(bool, ZapResourceArea, trueInDebug,                               \
 443           "Zap freed resource/arena space with 0xABABABAB")                 \
 444                                                                             \
 445   notproduct(bool, ZapVMHandleArea, trueInDebug,                            \
 446           "Zap freed VM handle space with 0xBCBCBCBC")                      \
 447                                                                             \
 448   notproduct(bool, ZapStackSegments, trueInDebug,                           \
 449           "Zap allocated/freed stack segments with 0xFADFADED")             \
 450                                                                             \
 451   develop(bool, ZapUnusedHeapArea, trueInDebug,                             \
 452           "Zap unused heap space with 0xBAADBABE")                          \
 453                                                                             \
 454   develop(bool, CheckZapUnusedHeapArea, false,                              \
 455           "Check zapping of unused heap space")                             \
 456                                                                             \
 457   develop(bool, ZapFillerObjects, trueInDebug,                              \
 458           "Zap filler objects with 0xDEAFBABE")                             \
 459                                                                             \
 460   develop(bool, PrintVMMessages, true,                                      \
 461           "Print VM messages on console")                                   \
 462                                                                             \
 463   notproduct(uintx, ErrorHandlerTest, 0,                                    \
 464           "If > 0, provokes an error after VM initialization; the value "   \
 465           "determines which error to provoke. See test_error_handler() "    \
 466           "in vmError.cpp.")                                                \
 467                                                                             \
 468   notproduct(uintx, TestCrashInErrorHandler, 0,                             \
 469           "If > 0, provokes an error inside VM error handler (a secondary " \
 470           "crash). see test_error_handler() in vmError.cpp")                \
 471                                                                             \
 472   notproduct(bool, TestSafeFetchInErrorHandler, false,                      \
 473           "If true, tests SafeFetch inside error handler.")                 \
 474                                                                             \
 475   notproduct(bool, TestUnresponsiveErrorHandler, false,                     \
 476           "If true, simulates an unresponsive error handler.")              \
 477                                                                             \
 478   develop(bool, Verbose, false,                                             \
 479           "Print additional debugging information from other modes")        \
 480                                                                             \
 481   develop(bool, PrintMiscellaneous, false,                                  \
 482           "Print uncategorized debugging information (requires +Verbose)")  \
 483                                                                             \
 484   develop(bool, WizardMode, false,                                          \
 485           "Print much more debugging information")                          \
 486                                                                             \
 487   product(bool, ShowMessageBoxOnError, false,                               \
 488           "Keep process alive on VM fatal error")                           \
 489                                                                             \
 490   product(bool, CreateCoredumpOnCrash, true,                                \
 491           "Create core/mini dump on VM fatal error")                        \
 492                                                                             \
 493   product(uint64_t, ErrorLogTimeout, 2 * 60,                                \
 494           "Timeout, in seconds, to limit the time spent on writing an "     \
 495           "error log in case of a crash.")                                  \
 496           range(0, (uint64_t)max_jlong/1000)                                \
 497                                                                             \
 498   product_pd(bool, UseOSErrorReporting,                                     \
 499           "Let VM fatal error propagate to the OS (ie. WER on Windows)")    \
 500                                                                             \
 501   product(bool, SuppressFatalErrorMessage, false,                           \
 502           "Report NO fatal error message (avoid deadlock)")                 \
 503                                                                             \
 504   product(ccstrlist, OnError, "",                                           \
 505           "Run user-defined commands on fatal error; see VMError.cpp "      \
 506           "for examples")                                                   \
 507                                                                             \
 508   product(ccstrlist, OnOutOfMemoryError, "",                                \
 509           "Run user-defined commands on first java.lang.OutOfMemoryError")  \
 510                                                                             \
 511   manageable(bool, HeapDumpBeforeFullGC, false,                             \
 512           "Dump heap to file before any major stop-the-world GC")           \
 513                                                                             \
 514   manageable(bool, HeapDumpAfterFullGC, false,                              \
 515           "Dump heap to file after any major stop-the-world GC")            \
 516                                                                             \
 517   manageable(bool, HeapDumpOnOutOfMemoryError, false,                       \
 518           "Dump heap to file when java.lang.OutOfMemoryError is thrown")    \
 519                                                                             \
 520   manageable(ccstr, HeapDumpPath, NULL,                                     \
 521           "When HeapDumpOnOutOfMemoryError is on, the path (filename or "   \
 522           "directory) of the dump file (defaults to java_pid<pid>.hprof "   \
 523           "in the working directory)")                                      \
 524                                                                             \
 525   develop(bool, BreakAtWarning, false,                                      \
 526           "Execute breakpoint upon encountering VM warning")                \
 527                                                                             \
 528   product(ccstr, NativeMemoryTracking, "off",                               \
 529           "Native memory tracking options")                                 \
 530                                                                             \
 531   diagnostic(bool, PrintNMTStatistics, false,                               \
 532           "Print native memory tracking summary data if it is on")          \
 533                                                                             \
 534   diagnostic(bool, LogCompilation, false,                                   \
 535           "Log compilation activity in detail to LogFile")                  \
 536                                                                             \
 537   product(bool, PrintCompilation, false,                                    \
 538           "Print compilations")                                             \
 539                                                                             \
 540   product(bool, PrintExtendedThreadInfo, false,                             \
 541           "Print more information in thread dump")                          \
 542                                                                             \
 543   diagnostic(intx, ScavengeRootsInCode, 2,                                  \
 544           "0: do not allow scavengable oops in the code cache; "            \
 545           "1: allow scavenging from the code cache; "                       \
 546           "2: emit as many constants as the compiler can see")              \
 547           range(0, 2)                                                       \
 548                                                                             \
 549   product(bool, AlwaysRestoreFPU, false,                                    \
 550           "Restore the FPU control word after every JNI call (expensive)")  \
 551                                                                             \
 552   diagnostic(bool, PrintCompilation2, false,                                \
 553           "Print additional statistics per compilation")                    \
 554                                                                             \
 555   diagnostic(bool, PrintAdapterHandlers, false,                             \
 556           "Print code generated for i2c/c2i adapters")                      \
 557                                                                             \
 558   diagnostic(bool, VerifyAdapterCalls, trueInDebug,                         \
 559           "Verify that i2c/c2i adapters are called properly")               \
 560                                                                             \
 561   develop(bool, VerifyAdapterSharing, false,                                \
 562           "Verify that the code for shared adapters is the equivalent")     \
 563                                                                             \
 564   diagnostic(bool, PrintAssembly, false,                                    \
 565           "Print assembly code (using external disassembler.so)")           \
 566                                                                             \
 567   diagnostic(ccstr, PrintAssemblyOptions, NULL,                             \
 568           "Print options string passed to disassembler.so")                 \
 569                                                                             \
 570   notproduct(bool, PrintNMethodStatistics, false,                           \
 571           "Print a summary statistic for the generated nmethods")           \
 572                                                                             \
 573   diagnostic(bool, PrintNMethods, false,                                    \
 574           "Print assembly code for nmethods when generated")                \
 575                                                                             \
 576   diagnostic(bool, PrintNativeNMethods, false,                              \
 577           "Print assembly code for native nmethods when generated")         \
 578                                                                             \
 579   develop(bool, PrintDebugInfo, false,                                      \
 580           "Print debug information for all nmethods when generated")        \
 581                                                                             \
 582   develop(bool, PrintRelocations, false,                                    \
 583           "Print relocation information for all nmethods when generated")   \
 584                                                                             \
 585   develop(bool, PrintDependencies, false,                                   \
 586           "Print dependency information for all nmethods when generated")   \
 587                                                                             \
 588   develop(bool, PrintExceptionHandlers, false,                              \
 589           "Print exception handler tables for all nmethods when generated") \
 590                                                                             \
 591   develop(bool, StressCompiledExceptionHandlers, false,                     \
 592           "Exercise compiled exception handlers")                           \
 593                                                                             \
 594   develop(bool, InterceptOSException, false,                                \
 595           "Start debugger when an implicit OS (e.g. NULL) "                 \
 596           "exception happens")                                              \
 597                                                                             \
 598   product(bool, PrintCodeCache, false,                                      \
 599           "Print the code cache memory usage when exiting")                 \
 600                                                                             \
 601   develop(bool, PrintCodeCache2, false,                                     \
 602           "Print detailed usage information on the code cache when exiting")\
 603                                                                             \
 604   product(bool, PrintCodeCacheOnCompilation, false,                         \
 605           "Print the code cache memory usage each time a method is "        \
 606           "compiled")                                                       \
 607                                                                             \
 608   diagnostic(bool, PrintCodeHeapAnalytics, false,                           \
 609           "Print code heap usage statistics on exit and on full condition") \
 610                                                                             \
 611   diagnostic(bool, PrintStubCode, false,                                    \
 612           "Print generated stub code")                                      \
 613                                                                             \
 614   product(bool, StackTraceInThrowable, true,                                \
 615           "Collect backtrace in throwable when exception happens")          \
 616                                                                             \
 617   product(bool, OmitStackTraceInFastThrow, true,                            \
 618           "Omit backtraces for some 'hot' exceptions in optimized code")    \
 619                                                                             \
 620   manageable(bool, ShowCodeDetailsInExceptionMessages, false,               \
 621           "Show exception messages from RuntimeExceptions that contain "    \
 622           "snippets of the failing code. Disable this to improve privacy.") \
 623                                                                             \
 624   product(bool, PrintWarnings, true,                                        \
 625           "Print JVM warnings to output stream")                            \
 626                                                                             \
 627   notproduct(uintx, WarnOnStalledSpinLock, 0,                               \
 628           "Print warnings for stalled SpinLocks")                           \
 629                                                                             \
 630   product(bool, RegisterFinalizersAtInit, true,                             \
 631           "Register finalizable objects at end of Object.<init> or "        \
 632           "after allocation")                                               \
 633                                                                             \
 634   develop(bool, RegisterReferences, true,                                   \
 635           "Tell whether the VM should register soft/weak/final/phantom "    \
 636           "references")                                                     \
 637                                                                             \
 638   develop(bool, IgnoreRewrites, false,                                      \
 639           "Suppress rewrites of bytecodes in the oopmap generator. "        \
 640           "This is unsafe!")                                                \
 641                                                                             \
 642   develop(bool, PrintCodeCacheExtension, false,                             \
 643           "Print extension of code cache")                                  \
 644                                                                             \
 645   develop(bool, UsePrivilegedStack, true,                                   \
 646           "Enable the security JVM functions")                              \
 647                                                                             \
 648   develop(bool, ProtectionDomainVerification, true,                         \
 649           "Verify protection domain before resolution in system dictionary")\
 650                                                                             \
 651   product(bool, ClassUnloading, true,                                       \
 652           "Do unloading of classes")                                        \
 653                                                                             \
 654   product(bool, ClassUnloadingWithConcurrentMark, true,                     \
 655           "Do unloading of classes with a concurrent marking cycle")        \
 656                                                                             \
 657   develop(bool, DisableStartThread, false,                                  \
 658           "Disable starting of additional Java threads "                    \
 659           "(for debugging only)")                                           \
 660                                                                             \
 661   develop(bool, MemProfiling, false,                                        \
 662           "Write memory usage profiling to log file")                       \
 663                                                                             \
 664   notproduct(bool, PrintSystemDictionaryAtExit, false,                      \
 665           "Print the system dictionary at exit")                            \
 666                                                                             \
 667   diagnostic(bool, DynamicallyResizeSystemDictionaries, true,               \
 668           "Dynamically resize system dictionaries as needed")               \
 669                                                                             \
 670   product(bool, AlwaysLockClassLoader, false,                               \
 671           "Require the VM to acquire the class loader lock before calling " \
 672           "loadClass() even for class loaders registering "                 \
 673           "as parallel capable")                                            \
 674                                                                             \
 675   product(bool, AllowParallelDefineClass, false,                            \
 676           "Allow parallel defineClass requests for class loaders "          \
 677           "registering as parallel capable")                                \
 678                                                                             \
 679   product_pd(bool, DontYieldALot,                                           \
 680           "Throw away obvious excess yield calls")                          \
 681                                                                             \
 682   experimental(bool, DisablePrimordialThreadGuardPages, false,              \
 683                "Disable the use of stack guard pages if the JVM is loaded " \
 684                "on the primordial process thread")                          \
 685                                                                             \
 686   product(bool, UseLWPSynchronization, true,                                \
 687           "Use LWP-based instead of libthread-based synchronization "       \
 688           "(SPARC only)")                                                   \
 689                                                                             \
 690   product(intx, MonitorBound, 0, "(Deprecated) Bound Monitor population")   \
 691           range(0, max_jint)                                                \
 692                                                                             \
 693   experimental(intx, MonitorUsedDeflationThreshold, 90,                     \
 694                 "Percentage of used monitors before triggering cleanup "    \
 695                 "safepoint which deflates monitors (0 is off). "            \
 696                 "The check is performed on GuaranteedSafepointInterval.")   \
 697                 range(0, 100)                                               \
 698                                                                             \
 699   experimental(intx, hashCode, 5,                                           \
 700                "(Unstable) select hashCode generation algorithm")           \
 701                                                                             \
 702   product(bool, FilterSpuriousWakeups, true,                                \
 703           "When true prevents OS-level spurious, or premature, wakeups "    \
 704           "from Object.wait (Ignored for Windows)")                         \
 705                                                                             \
 706   product(bool, ReduceSignalUsage, false,                                   \
 707           "Reduce the use of OS signals in Java and/or the VM")             \
 708                                                                             \
 709   develop(bool, LoadLineNumberTables, true,                                 \
 710           "Tell whether the class file parser loads line number tables")    \
 711                                                                             \
 712   develop(bool, LoadLocalVariableTables, true,                              \
 713           "Tell whether the class file parser loads local variable tables") \
 714                                                                             \
 715   develop(bool, LoadLocalVariableTypeTables, true,                          \
 716           "Tell whether the class file parser loads local variable type"    \
 717           "tables")                                                         \
 718                                                                             \
 719   product(bool, AllowUserSignalHandlers, false,                             \
 720           "Do not complain if the application installs signal handlers "    \
 721           "(Unix only)")                                                    \
 722                                                                             \
 723   product(bool, UseSignalChaining, true,                                    \
 724           "Use signal-chaining to invoke signal handlers installed "        \
 725           "by the application (Unix only)")                                 \
 726                                                                             \
 727   product(bool, RestoreMXCSROnJNICalls, false,                              \
 728           "Restore MXCSR when returning from JNI calls")                    \
 729                                                                             \
 730   product(bool, CheckJNICalls, false,                                       \
 731           "Verify all arguments to JNI calls")                              \
 732                                                                             \
 733   product(bool, UseFastJNIAccessors, true,                                  \
 734           "Use optimized versions of Get<Primitive>Field")                  \
 735                                                                             \
 736   product(intx, MaxJNILocalCapacity, 65536,                                 \
 737           "Maximum allowable local JNI handle capacity to "                 \
 738           "EnsureLocalCapacity() and PushLocalFrame(), "                    \
 739           "where <= 0 is unlimited, default: 65536")                        \
 740           range(min_intx, max_intx)                                         \
 741                                                                             \
 742   product(bool, EagerXrunInit, false,                                       \
 743           "Eagerly initialize -Xrun libraries; allows startup profiling, "  \
 744           "but not all -Xrun libraries may support the state of the VM "    \
 745           "at this time")                                                   \
 746                                                                             \
 747   product(bool, PreserveAllAnnotations, false,                              \
 748           "Preserve RuntimeInvisibleAnnotations as well "                   \
 749           "as RuntimeVisibleAnnotations")                                   \
 750                                                                             \
 751   develop(uintx, PreallocatedOutOfMemoryErrorCount, 4,                      \
 752           "Number of OutOfMemoryErrors preallocated with backtrace")        \
 753                                                                             \
 754   product(bool, UseXMMForArrayCopy, false,                                  \
 755           "Use SSE2 MOVQ instruction for Arraycopy")                        \
 756                                                                             \
 757   notproduct(bool, PrintFieldLayout, false,                                 \
 758           "Print field layout for each class")                              \
 759                                                                             \
 760   /* Need to limit the extent of the padding to reasonable size.          */\
 761   /* 8K is well beyond the reasonable HW cache line size, even with       */\
 762   /* aggressive prefetching, while still leaving the room for segregating */\
 763   /* among the distinct pages.                                            */\
 764   product(intx, ContendedPaddingWidth, 128,                                 \
 765           "How many bytes to pad the fields/classes marked @Contended with")\
 766           range(0, 8192)                                                    \
 767           constraint(ContendedPaddingWidthConstraintFunc,AfterErgo)         \
 768                                                                             \
 769   product(bool, EnableContended, true,                                      \
 770           "Enable @Contended annotation support")                           \
 771                                                                             \
 772   product(bool, RestrictContended, true,                                    \
 773           "Restrict @Contended to trusted classes")                         \
 774                                                                             \
 775   product(bool, UseBiasedLocking, true,                                     \
 776           "Enable biased locking in JVM")                                   \
 777                                                                             \
 778   product(intx, BiasedLockingStartupDelay, 0,                               \
 779           "Number of milliseconds to wait before enabling biased locking")  \
 780           range(0, (intx)(max_jint-(max_jint%PeriodicTask::interval_gran))) \
 781           constraint(BiasedLockingStartupDelayFunc,AfterErgo)               \
 782                                                                             \
 783   diagnostic(bool, PrintBiasedLockingStatistics, false,                     \
 784           "Print statistics of biased locking in JVM")                      \
 785                                                                             \
 786   product(intx, BiasedLockingBulkRebiasThreshold, 20,                       \
 787           "Threshold of number of revocations per type to try to "          \
 788           "rebias all objects in the heap of that type")                    \
 789           range(0, max_intx)                                                \
 790           constraint(BiasedLockingBulkRebiasThresholdFunc,AfterErgo)        \
 791                                                                             \
 792   product(intx, BiasedLockingBulkRevokeThreshold, 40,                       \
 793           "Threshold of number of revocations per type to permanently "     \
 794           "revoke biases of all objects in the heap of that type")          \
 795           range(0, max_intx)                                                \
 796           constraint(BiasedLockingBulkRevokeThresholdFunc,AfterErgo)        \
 797                                                                             \
 798   product(intx, BiasedLockingDecayTime, 25000,                              \
 799           "Decay time (in milliseconds) to re-enable bulk rebiasing of a "  \
 800           "type after previous bulk rebias")                                \
 801           range(500, max_intx)                                              \
 802           constraint(BiasedLockingDecayTimeFunc,AfterErgo)                  \
 803                                                                             \
 804   product(bool, ExitOnOutOfMemoryError, false,                              \
 805           "JVM exits on the first occurrence of an out-of-memory error")    \
 806                                                                             \
 807   product(bool, CrashOnOutOfMemoryError, false,                             \
 808           "JVM aborts, producing an error log and core/mini dump, on the "  \
 809           "first occurrence of an out-of-memory error")                     \
 810                                                                             \
 811   /* tracing */                                                             \
 812                                                                             \
 813   develop(bool, StressRewriter, false,                                      \
 814           "Stress linktime bytecode rewriting")                             \
 815                                                                             \
 816   product(ccstr, TraceJVMTI, NULL,                                          \
 817           "Trace flags for JVMTI functions and events")                     \
 818                                                                             \
 819   /* This option can change an EMCP method into an obsolete method. */      \
 820   /* This can affect tests that except specific methods to be EMCP. */      \
 821   /* This option should be used with caution.                       */      \
 822   product(bool, StressLdcRewrite, false,                                    \
 823           "Force ldc -> ldc_w rewrite during RedefineClasses")              \
 824                                                                             \
 825   /* change to false by default sometime after Mustang */                   \
 826   product(bool, VerifyMergedCPBytecodes, true,                              \
 827           "Verify bytecodes after RedefineClasses constant pool merging")   \
 828                                                                             \
 829   product(bool, AllowRedefinitionToAddDeleteMethods, false,                 \
 830           "(Deprecated) Allow redefinition to add and delete private "      \
 831           "static or final methods for compatibility with old releases")    \
 832                                                                             \
 833   develop(bool, TraceBytecodes, false,                                      \
 834           "Trace bytecode execution")                                       \
 835                                                                             \
 836   develop(bool, TraceICs, false,                                            \
 837           "Trace inline cache changes")                                     \
 838                                                                             \
 839   notproduct(bool, TraceInvocationCounterOverflow, false,                   \
 840           "Trace method invocation counter overflow")                       \
 841                                                                             \
 842   develop(bool, TraceInlineCacheClearing, false,                            \
 843           "Trace clearing of inline caches in nmethods")                    \
 844                                                                             \
 845   develop(bool, TraceDependencies, false,                                   \
 846           "Trace dependencies")                                             \
 847                                                                             \
 848   develop(bool, VerifyDependencies, trueInDebug,                            \
 849           "Exercise and verify the compilation dependency mechanism")       \
 850                                                                             \
 851   develop(bool, TraceNewOopMapGeneration, false,                            \
 852           "Trace OopMapGeneration")                                         \
 853                                                                             \
 854   develop(bool, TraceNewOopMapGenerationDetailed, false,                    \
 855           "Trace OopMapGeneration: print detailed cell states")             \
 856                                                                             \
 857   develop(bool, TimeOopMap, false,                                          \
 858           "Time calls to GenerateOopMap::compute_map() in sum")             \
 859                                                                             \
 860   develop(bool, TimeOopMap2, false,                                         \
 861           "Time calls to GenerateOopMap::compute_map() individually")       \
 862                                                                             \
 863   develop(bool, TraceOopMapRewrites, false,                                 \
 864           "Trace rewriting of method oops during oop map generation")       \
 865                                                                             \
 866   develop(bool, TraceICBuffer, false,                                       \
 867           "Trace usage of IC buffer")                                       \
 868                                                                             \
 869   develop(bool, TraceCompiledIC, false,                                     \
 870           "Trace changes of compiled IC")                                   \
 871                                                                             \
 872   develop(bool, FLSVerifyDictionary, false,                                 \
 873           "Do lots of (expensive) FLS dictionary verification")             \
 874                                                                             \
 875                                                                             \
 876   notproduct(bool, CheckMemoryInitialization, false,                        \
 877           "Check memory initialization")                                    \
 878                                                                             \
 879   product(uintx, ProcessDistributionStride, 4,                              \
 880           "Stride through processors when distributing processes")          \
 881           range(0, max_juint)                                               \
 882                                                                             \
 883   develop(bool, TraceFinalizerRegistration, false,                          \
 884           "Trace registration of final references")                         \
 885                                                                             \
 886   product(bool, IgnoreEmptyClassPaths, false,                               \
 887           "Ignore empty path elements in -classpath")                       \
 888                                                                             \
 889   product(size_t, InitialBootClassLoaderMetaspaceSize,                      \
 890           NOT_LP64(2200*K) LP64_ONLY(4*M),                                  \
 891           "Initial size of the boot class loader data metaspace")           \
 892           range(30*K, max_uintx/BytesPerWord)                               \
 893           constraint(InitialBootClassLoaderMetaspaceSizeConstraintFunc, AfterErgo)\
 894                                                                             \
 895   product(bool, PrintHeapAtSIGBREAK, true,                                  \
 896           "Print heap layout in response to SIGBREAK")                      \
 897                                                                             \
 898   manageable(bool, PrintClassHistogram, false,                              \
 899           "Print a histogram of class instances")                           \
 900                                                                             \
 901   experimental(double, ObjectCountCutOffPercent, 0.5,                       \
 902           "The percentage of the used heap that the instances of a class "  \
 903           "must occupy for the class to generate a trace event")            \
 904           range(0.0, 100.0)                                                 \
 905                                                                             \
 906   /* JVMTI heap profiling */                                                \
 907                                                                             \
 908   diagnostic(bool, TraceJVMTIObjectTagging, false,                          \
 909           "Trace JVMTI object tagging calls")                               \
 910                                                                             \
 911   diagnostic(bool, VerifyBeforeIteration, false,                            \
 912           "Verify memory system before JVMTI iteration")                    \
 913                                                                             \
 914   /* compiler interface */                                                  \
 915                                                                             \
 916   develop(bool, CIPrintCompilerName, false,                                 \
 917           "when CIPrint is active, print the name of the active compiler")  \
 918                                                                             \
 919   diagnostic(bool, CIPrintCompileQueue, false,                              \
 920           "display the contents of the compile queue whenever a "           \
 921           "compilation is enqueued")                                        \
 922                                                                             \
 923   develop(bool, CIPrintRequests, false,                                     \
 924           "display every request for compilation")                          \
 925                                                                             \
 926   product(bool, CITime, false,                                              \
 927           "collect timing information for compilation")                     \
 928                                                                             \
 929   develop(bool, CITimeVerbose, false,                                       \
 930           "be more verbose in compilation timings")                         \
 931                                                                             \
 932   develop(bool, CITimeEach, false,                                          \
 933           "display timing information after each successful compilation")   \
 934                                                                             \
 935   develop(bool, CICountOSR, false,                                          \
 936           "use a separate counter when assigning ids to osr compilations")  \
 937                                                                             \
 938   develop(bool, CICompileNatives, true,                                     \
 939           "compile native methods if supported by the compiler")            \
 940                                                                             \
 941   develop_pd(bool, CICompileOSR,                                            \
 942           "compile on stack replacement methods if supported by the "       \
 943           "compiler")                                                       \
 944                                                                             \
 945   develop(bool, CIPrintMethodCodes, false,                                  \
 946           "print method bytecodes of the compiled code")                    \
 947                                                                             \
 948   develop(bool, CIPrintTypeFlow, false,                                     \
 949           "print the results of ciTypeFlow analysis")                       \
 950                                                                             \
 951   develop(bool, CITraceTypeFlow, false,                                     \
 952           "detailed per-bytecode tracing of ciTypeFlow analysis")           \
 953                                                                             \
 954   develop(intx, OSROnlyBCI, -1,                                             \
 955           "OSR only at this bci.  Negative values mean exclude that bci")   \
 956                                                                             \
 957   /* compiler */                                                            \
 958                                                                             \
 959   /* notice: the max range value here is max_jint, not max_intx  */         \
 960   /* because of overflow issue                                   */         \
 961   product(intx, CICompilerCount, CI_COMPILER_COUNT,                         \
 962           "Number of compiler threads to run")                              \
 963           range(0, max_jint)                                                \
 964           constraint(CICompilerCountConstraintFunc, AfterErgo)              \
 965                                                                             \
 966   product(bool, UseDynamicNumberOfCompilerThreads, true,                    \
 967           "Dynamically choose the number of parallel compiler threads")     \
 968                                                                             \
 969   diagnostic(bool, ReduceNumberOfCompilerThreads, true,                     \
 970              "Reduce the number of parallel compiler threads when they "    \
 971              "are not used")                                                \
 972                                                                             \
 973   diagnostic(bool, TraceCompilerThreads, false,                             \
 974              "Trace creation and removal of compiler threads")              \
 975                                                                             \
 976   develop(bool, InjectCompilerCreationFailure, false,                       \
 977           "Inject thread creation failures for "                            \
 978           "UseDynamicNumberOfCompilerThreads")                              \
 979                                                                             \
 980   develop(bool, UseStackBanging, true,                                      \
 981           "use stack banging for stack overflow checks (required for "      \
 982           "proper StackOverflow handling; disable only to measure cost "    \
 983           "of stackbanging)")                                               \
 984                                                                             \
 985   develop(bool, GenerateSynchronizationCode, true,                          \
 986           "generate locking/unlocking code for synchronized methods and "   \
 987           "monitors")                                                       \
 988                                                                             \
 989   develop(bool, GenerateRangeChecks, true,                                  \
 990           "Generate range checks for array accesses")                       \
 991                                                                             \
 992   diagnostic_pd(bool, ImplicitNullChecks,                                   \
 993           "Generate code for implicit null checks")                         \
 994                                                                             \
 995   product_pd(bool, TrapBasedNullChecks,                                     \
 996           "Generate code for null checks that uses a cmp and trap "         \
 997           "instruction raising SIGTRAP.  This is only used if an access to" \
 998           "null (+offset) will not raise a SIGSEGV, i.e.,"                  \
 999           "ImplicitNullChecks don't work (PPC64).")                         \
1000                                                                             \
1001   diagnostic(bool, EnableThreadSMRExtraValidityChecks, true,                \
1002              "Enable Thread SMR extra validity checks")                     \
1003                                                                             \
1004   diagnostic(bool, EnableThreadSMRStatistics, trueInDebug,                  \
1005              "Enable Thread SMR Statistics")                                \
1006                                                                             \
1007   product(bool, UseNotificationThread, true,                                \
1008           "Use Notification Thread")                                        \
1009                                                                             \
1010   product(bool, Inline, true,                                               \
1011           "Enable inlining")                                                \
1012                                                                             \
1013   product(bool, ClipInlining, true,                                         \
1014           "Clip inlining if aggregate method exceeds DesiredMethodLimit")   \
1015                                                                             \
1016   develop(bool, UseCHA, true,                                               \
1017           "Enable CHA")                                                     \
1018                                                                             \
1019   product(bool, UseTypeProfile, true,                                       \
1020           "Check interpreter profile for historically monomorphic calls")   \
1021                                                                             \
1022   diagnostic(bool, PrintInlining, false,                                    \
1023           "Print inlining optimizations")                                   \
1024                                                                             \
1025   product(bool, UsePopCountInstruction, false,                              \
1026           "Use population count instruction")                               \
1027                                                                             \
1028   develop(bool, EagerInitialization, false,                                 \
1029           "Eagerly initialize classes if possible")                         \
1030                                                                             \
1031   diagnostic(bool, LogTouchedMethods, false,                                \
1032           "Log methods which have been ever touched in runtime")            \
1033                                                                             \
1034   diagnostic(bool, PrintTouchedMethodsAtExit, false,                        \
1035           "Print all methods that have been ever touched in runtime")       \
1036                                                                             \
1037   develop(bool, TraceMethodReplacement, false,                              \
1038           "Print when methods are replaced do to recompilation")            \
1039                                                                             \
1040   develop(bool, PrintMethodFlushing, false,                                 \
1041           "Print the nmethods being flushed")                               \
1042                                                                             \
1043   diagnostic(bool, PrintMethodFlushingStatistics, false,                    \
1044           "print statistics about method flushing")                         \
1045                                                                             \
1046   diagnostic(intx, HotMethodDetectionLimit, 100000,                         \
1047           "Number of compiled code invocations after which "                \
1048           "the method is considered as hot by the flusher")                 \
1049           range(1, max_jint)                                                \
1050                                                                             \
1051   diagnostic(intx, MinPassesBeforeFlush, 10,                                \
1052           "Minimum number of sweeper passes before an nmethod "             \
1053           "can be flushed")                                                 \
1054           range(0, max_intx)                                                \
1055                                                                             \
1056   product(bool, UseCodeAging, true,                                         \
1057           "Insert counter to detect warm methods")                          \
1058                                                                             \
1059   diagnostic(bool, StressCodeAging, false,                                  \
1060           "Start with counters compiled in")                                \
1061                                                                             \
1062   develop(bool, StressCodeBuffers, false,                                   \
1063           "Exercise code buffer expansion and other rare state changes")    \
1064                                                                             \
1065   diagnostic(bool, DebugNonSafepoints, trueInDebug,                         \
1066           "Generate extra debugging information for non-safepoints in "     \
1067           "nmethods")                                                       \
1068                                                                             \
1069   product(bool, PrintVMOptions, false,                                      \
1070           "Print flags that appeared on the command line")                  \
1071                                                                             \
1072   product(bool, IgnoreUnrecognizedVMOptions, false,                         \
1073           "Ignore unrecognized VM options")                                 \
1074                                                                             \
1075   product(bool, PrintCommandLineFlags, false,                               \
1076           "Print flags specified on command line or set by ergonomics")     \
1077                                                                             \
1078   product(bool, PrintFlagsInitial, false,                                   \
1079           "Print all VM flags before argument processing and exit VM")      \
1080                                                                             \
1081   product(bool, PrintFlagsFinal, false,                                     \
1082           "Print all VM flags after argument and ergonomic processing")     \
1083                                                                             \
1084   notproduct(bool, PrintFlagsWithComments, false,                           \
1085           "Print all VM flags with default values and descriptions and "    \
1086           "exit")                                                           \
1087                                                                             \
1088   product(bool, PrintFlagsRanges, false,                                    \
1089           "Print VM flags and their ranges")                                \
1090                                                                             \
1091   diagnostic(bool, SerializeVMOutput, true,                                 \
1092           "Use a mutex to serialize output to tty and LogFile")             \
1093                                                                             \
1094   diagnostic(bool, DisplayVMOutput, true,                                   \
1095           "Display all VM output on the tty, independently of LogVMOutput") \
1096                                                                             \
1097   diagnostic(bool, LogVMOutput, false,                                      \
1098           "Save VM output to LogFile")                                      \
1099                                                                             \
1100   diagnostic(ccstr, LogFile, NULL,                                          \
1101           "If LogVMOutput or LogCompilation is on, save VM output to "      \
1102           "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1103                                                                             \
1104   product(ccstr, ErrorFile, NULL,                                           \
1105           "If an error occurs, save the error data to this file "           \
1106           "[default: ./hs_err_pid%p.log] (%p replaced with pid)")           \
1107                                                                             \
1108   product(bool, ExtensiveErrorReports,                                      \
1109           PRODUCT_ONLY(false) NOT_PRODUCT(true),                            \
1110           "Error reports are more extensive.")                              \
1111                                                                             \
1112   product(bool, DisplayVMOutputToStderr, false,                             \
1113           "If DisplayVMOutput is true, display all VM output to stderr")    \
1114                                                                             \
1115   product(bool, DisplayVMOutputToStdout, false,                             \
1116           "If DisplayVMOutput is true, display all VM output to stdout")    \
1117                                                                             \
1118   product(bool, ErrorFileToStderr, false,                                   \
1119           "If true, error data is printed to stderr instead of a file")     \
1120                                                                             \
1121   product(bool, ErrorFileToStdout, false,                                   \
1122           "If true, error data is printed to stdout instead of a file")     \
1123                                                                             \
1124   product(bool, UseHeavyMonitors, false,                                    \
1125           "use heavyweight instead of lightweight Java monitors")           \
1126                                                                             \
1127   product(bool, PrintStringTableStatistics, false,                          \
1128           "print statistics about the StringTable and SymbolTable")         \
1129                                                                             \
1130   diagnostic(bool, VerifyStringTableAtExit, false,                          \
1131           "verify StringTable contents at exit")                            \
1132                                                                             \
1133   notproduct(bool, PrintSymbolTableSizeHistogram, false,                    \
1134           "print histogram of the symbol table")                            \
1135                                                                             \
1136   notproduct(bool, ExitVMOnVerifyError, false,                              \
1137           "standard exit from VM if bytecode verify error "                 \
1138           "(only in debug mode)")                                           \
1139                                                                             \
1140   diagnostic(ccstr, AbortVMOnException, NULL,                               \
1141           "Call fatal if this exception is thrown.  Example: "              \
1142           "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1143                                                                             \
1144   diagnostic(ccstr, AbortVMOnExceptionMessage, NULL,                        \
1145           "Call fatal if the exception pointed by AbortVMOnException "      \
1146           "has this message")                                               \
1147                                                                             \
1148   develop(bool, DebugVtables, false,                                        \
1149           "add debugging code to vtable dispatch")                          \
1150                                                                             \
1151   notproduct(bool, PrintVtableStats, false,                                 \
1152           "print vtables stats at end of run")                              \
1153                                                                             \
1154   develop(bool, TraceCreateZombies, false,                                  \
1155           "trace creation of zombie nmethods")                              \
1156                                                                             \
1157   product(bool, RangeCheckElimination, true,                                \
1158           "Eliminate range checks")                                         \
1159                                                                             \
1160   develop_pd(bool, UncommonNullCast,                                        \
1161           "track occurrences of null in casts; adjust compiler tactics")    \
1162                                                                             \
1163   develop(bool, TypeProfileCasts,  true,                                    \
1164           "treat casts like calls for purposes of type profiling")          \
1165                                                                             \
1166   develop(bool, TraceLivenessGen, false,                                    \
1167           "Trace the generation of liveness analysis information")          \
1168                                                                             \
1169   notproduct(bool, TraceLivenessQuery, false,                               \
1170           "Trace queries of liveness analysis information")                 \
1171                                                                             \
1172   notproduct(bool, CollectIndexSetStatistics, false,                        \
1173           "Collect information about IndexSets")                            \
1174                                                                             \
1175   develop(bool, UseLoopSafepoints, true,                                    \
1176           "Generate Safepoint nodes in every loop")                         \
1177                                                                             \
1178   develop(intx, FastAllocateSizeLimit, 128*K,                               \
1179           /* Note:  This value is zero mod 1<<13 for a cheap sparc set. */  \
1180           "Inline allocations larger than this in doublewords must go slow")\
1181                                                                             \
1182   product_pd(bool, CompactStrings,                                          \
1183           "Enable Strings to use single byte chars in backing store")       \
1184                                                                             \
1185   product_pd(uintx, TypeProfileLevel,                                       \
1186           "=XYZ, with Z: Type profiling of arguments at call; "             \
1187                      "Y: Type profiling of return value at call; "          \
1188                      "X: Type profiling of parameters to methods; "         \
1189           "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods")             \
1190           constraint(TypeProfileLevelConstraintFunc, AfterErgo)             \
1191                                                                             \
1192   product(intx, TypeProfileArgsLimit,     2,                                \
1193           "max number of call arguments to consider for type profiling")    \
1194           range(0, 16)                                                      \
1195                                                                             \
1196   product(intx, TypeProfileParmsLimit,    2,                                \
1197           "max number of incoming parameters to consider for type profiling"\
1198           ", -1 for all")                                                   \
1199           range(-1, 64)                                                     \
1200                                                                             \
1201   /* statistics */                                                          \
1202   develop(bool, CountCompiledCalls, false,                                  \
1203           "Count method invocations")                                       \
1204                                                                             \
1205   notproduct(bool, CountRuntimeCalls, false,                                \
1206           "Count VM runtime calls")                                         \
1207                                                                             \
1208   develop(bool, CountJNICalls, false,                                       \
1209           "Count jni method invocations")                                   \
1210                                                                             \
1211   notproduct(bool, CountJVMCalls, false,                                    \
1212           "Count jvm method invocations")                                   \
1213                                                                             \
1214   notproduct(bool, CountRemovableExceptions, false,                         \
1215           "Count exceptions that could be replaced by branches due to "     \
1216           "inlining")                                                       \
1217                                                                             \
1218   notproduct(bool, ICMissHistogram, false,                                  \
1219           "Produce histogram of IC misses")                                 \
1220                                                                             \
1221   /* interpreter */                                                         \
1222   product_pd(bool, RewriteBytecodes,                                        \
1223           "Allow rewriting of bytecodes (bytecodes are not immutable)")     \
1224                                                                             \
1225   product_pd(bool, RewriteFrequentPairs,                                    \
1226           "Rewrite frequently used bytecode pairs into a single bytecode")  \
1227                                                                             \
1228   diagnostic(bool, PrintInterpreter, false,                                 \
1229           "Print the generated interpreter code")                           \
1230                                                                             \
1231   product(bool, UseInterpreter, true,                                       \
1232           "Use interpreter for non-compiled methods")                       \
1233                                                                             \
1234   develop(bool, UseFastSignatureHandlers, true,                             \
1235           "Use fast signature handlers for native calls")                   \
1236                                                                             \
1237   product(bool, UseLoopCounter, true,                                       \
1238           "Increment invocation counter on backward branch")                \
1239                                                                             \
1240   product_pd(bool, UseOnStackReplacement,                                   \
1241           "Use on stack replacement, calls runtime if invoc. counter "      \
1242           "overflows in loop")                                              \
1243                                                                             \
1244   notproduct(bool, TraceOnStackReplacement, false,                          \
1245           "Trace on stack replacement")                                     \
1246                                                                             \
1247   product_pd(bool, PreferInterpreterNativeStubs,                            \
1248           "Use always interpreter stubs for native methods invoked via "    \
1249           "interpreter")                                                    \
1250                                                                             \
1251   develop(bool, CountBytecodes, false,                                      \
1252           "Count number of bytecodes executed")                             \
1253                                                                             \
1254   develop(bool, PrintBytecodeHistogram, false,                              \
1255           "Print histogram of the executed bytecodes")                      \
1256                                                                             \
1257   develop(bool, PrintBytecodePairHistogram, false,                          \
1258           "Print histogram of the executed bytecode pairs")                 \
1259                                                                             \
1260   diagnostic(bool, PrintSignatureHandlers, false,                           \
1261           "Print code generated for native method signature handlers")      \
1262                                                                             \
1263   develop(bool, VerifyOops, false,                                          \
1264           "Do plausibility checks for oops")                                \
1265                                                                             \
1266   develop(bool, CheckUnhandledOops, false,                                  \
1267           "Check for unhandled oops in VM code")                            \
1268                                                                             \
1269   develop(bool, VerifyJNIFields, trueInDebug,                               \
1270           "Verify jfieldIDs for instance fields")                           \
1271                                                                             \
1272   notproduct(bool, VerifyJNIEnvThread, false,                               \
1273           "Verify JNIEnv.thread == Thread::current() when entering VM "     \
1274           "from JNI")                                                       \
1275                                                                             \
1276   develop(bool, VerifyFPU, false,                                           \
1277           "Verify FPU state (check for NaN's, etc.)")                       \
1278                                                                             \
1279   develop(bool, VerifyThread, false,                                        \
1280           "Watch the thread register for corruption (SPARC only)")          \
1281                                                                             \
1282   develop(bool, VerifyActivationFrameSize, false,                           \
1283           "Verify that activation frame didn't become smaller than its "    \
1284           "minimal size")                                                   \
1285                                                                             \
1286   develop(bool, TraceFrequencyInlining, false,                              \
1287           "Trace frequency based inlining")                                 \
1288                                                                             \
1289   develop_pd(bool, InlineIntrinsics,                                        \
1290           "Inline intrinsics that can be statically resolved")              \
1291                                                                             \
1292   product_pd(bool, ProfileInterpreter,                                      \
1293           "Profile at the bytecode level during interpretation")            \
1294                                                                             \
1295   develop(bool, TraceProfileInterpreter, false,                             \
1296           "Trace profiling at the bytecode level during interpretation. "   \
1297           "This outputs the profiling information collected to improve "    \
1298           "jit compilation.")                                               \
1299                                                                             \
1300   develop_pd(bool, ProfileTraps,                                            \
1301           "Profile deoptimization traps at the bytecode level")             \
1302                                                                             \
1303   product(intx, ProfileMaturityPercentage, 20,                              \
1304           "number of method invocations/branches (expressed as % of "       \
1305           "CompileThreshold) before using the method's profile")            \
1306           range(0, 100)                                                     \
1307                                                                             \
1308   diagnostic(bool, PrintMethodData, false,                                  \
1309           "Print the results of +ProfileInterpreter at end of run")         \
1310                                                                             \
1311   develop(bool, VerifyDataPointer, trueInDebug,                             \
1312           "Verify the method data pointer during interpreter profiling")    \
1313                                                                             \
1314   develop(bool, VerifyCompiledCode, false,                                  \
1315           "Include miscellaneous runtime verifications in nmethod code; "   \
1316           "default off because it disturbs nmethod size heuristics")        \
1317                                                                             \
1318   notproduct(bool, CrashGCForDumpingJavaThread, false,                      \
1319           "Manually make GC thread crash then dump java stack trace;  "     \
1320           "Test only")                                                      \
1321                                                                             \
1322   /* compilation */                                                         \
1323   product(bool, UseCompiler, true,                                          \
1324           "Use Just-In-Time compilation")                                   \
1325                                                                             \
1326   product(bool, UseCounterDecay, true,                                      \
1327           "Adjust recompilation counters")                                  \
1328                                                                             \
1329   develop(intx, CounterHalfLifeTime,    30,                                 \
1330           "Half-life time of invocation counters (in seconds)")             \
1331                                                                             \
1332   develop(intx, CounterDecayMinIntervalLength,   500,                       \
1333           "The minimum interval (in milliseconds) between invocation of "   \
1334           "CounterDecay")                                                   \
1335                                                                             \
1336   product(bool, AlwaysCompileLoopMethods, false,                            \
1337           "When using recompilation, never interpret methods "              \
1338           "containing loops")                                               \
1339                                                                             \
1340   product(bool, DontCompileHugeMethods, true,                               \
1341           "Do not compile methods > HugeMethodLimit")                       \
1342                                                                             \
1343   /* Bytecode escape analysis estimation. */                                \
1344   product(bool, EstimateArgEscape, true,                                    \
1345           "Analyze bytecodes to estimate escape state of arguments")        \
1346                                                                             \
1347   product(intx, BCEATraceLevel, 0,                                          \
1348           "How much tracing to do of bytecode escape analysis estimates "   \
1349           "(0-3)")                                                          \
1350           range(0, 3)                                                       \
1351                                                                             \
1352   product(intx, MaxBCEAEstimateLevel, 5,                                    \
1353           "Maximum number of nested calls that are analyzed by BC EA")      \
1354           range(0, max_jint)                                                \
1355                                                                             \
1356   product(intx, MaxBCEAEstimateSize, 150,                                   \
1357           "Maximum bytecode size of a method to be analyzed by BC EA")      \
1358           range(0, max_jint)                                                \
1359                                                                             \
1360   product(intx,  AllocatePrefetchStyle, 1,                                  \
1361           "0 = no prefetch, "                                               \
1362           "1 = generate prefetch instructions for each allocation, "        \
1363           "2 = use TLAB watermark to gate allocation prefetch, "            \
1364           "3 = generate one prefetch instruction per cache line")           \
1365           range(0, 3)                                                       \
1366                                                                             \
1367   product(intx,  AllocatePrefetchDistance, -1,                              \
1368           "Distance to prefetch ahead of allocation pointer. "              \
1369           "-1: use system-specific value (automatically determined")        \
1370           constraint(AllocatePrefetchDistanceConstraintFunc,AfterMemoryInit)\
1371                                                                             \
1372   product(intx,  AllocatePrefetchLines, 3,                                  \
1373           "Number of lines to prefetch ahead of array allocation pointer")  \
1374           range(1, 64)                                                      \
1375                                                                             \
1376   product(intx,  AllocateInstancePrefetchLines, 1,                          \
1377           "Number of lines to prefetch ahead of instance allocation "       \
1378           "pointer")                                                        \
1379           range(1, 64)                                                      \
1380                                                                             \
1381   product(intx,  AllocatePrefetchStepSize, 16,                              \
1382           "Step size in bytes of sequential prefetch instructions")         \
1383           range(1, 512)                                                     \
1384           constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1385                                                                             \
1386   product(intx,  AllocatePrefetchInstr, 0,                                  \
1387           "Select instruction to prefetch ahead of allocation pointer")     \
1388           constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit)  \
1389                                                                             \
1390   /* deoptimization */                                                      \
1391   develop(bool, TraceDeoptimization, false,                                 \
1392           "Trace deoptimization")                                           \
1393                                                                             \
1394   develop(bool, PrintDeoptimizationDetails, false,                          \
1395           "Print more information about deoptimization")                    \
1396                                                                             \
1397   develop(bool, DebugDeoptimization, false,                                 \
1398           "Tracing various information while debugging deoptimization")     \
1399                                                                             \
1400   product(intx, SelfDestructTimer, 0,                                       \
1401           "Will cause VM to terminate after a given time (in minutes) "     \
1402           "(0 means off)")                                                  \
1403           range(0, max_intx)                                                \
1404                                                                             \
1405   product(intx, MaxJavaStackTraceDepth, 1024,                               \
1406           "The maximum number of lines in the stack trace for Java "        \
1407           "exceptions (0 means all)")                                       \
1408           range(0, max_jint/2)                                              \
1409                                                                             \
1410   /* notice: the max range value here is max_jint, not max_intx  */         \
1411   /* because of overflow issue                                   */         \
1412   diagnostic(intx, GuaranteedSafepointInterval, 1000,                       \
1413           "Guarantee a safepoint (at least) every so many milliseconds "    \
1414           "(0 means none)")                                                 \
1415           range(0, max_jint)                                                \
1416                                                                             \
1417   product(intx, SafepointTimeoutDelay, 10000,                               \
1418           "Delay in milliseconds for option SafepointTimeout")              \
1419   LP64_ONLY(range(0, max_intx/MICROUNITS))                                  \
1420   NOT_LP64(range(0, max_intx))                                              \
1421                                                                             \
1422   product(intx, NmethodSweepActivity, 10,                                   \
1423           "Removes cold nmethods from code cache if > 0. Higher values "    \
1424           "result in more aggressive sweeping")                             \
1425           range(0, 2000)                                                    \
1426                                                                             \
1427   notproduct(bool, LogSweeper, false,                                       \
1428           "Keep a ring buffer of sweeper activity")                         \
1429                                                                             \
1430   notproduct(intx, SweeperLogEntries, 1024,                                 \
1431           "Number of records in the ring buffer of sweeper activity")       \
1432                                                                             \
1433   notproduct(intx, MemProfilingInterval, 500,                               \
1434           "Time between each invocation of the MemProfiler")                \
1435                                                                             \
1436   develop(intx, MallocCatchPtr, -1,                                         \
1437           "Hit breakpoint when mallocing/freeing this pointer")             \
1438                                                                             \
1439   notproduct(ccstrlist, SuppressErrorAt, "",                                \
1440           "List of assertions (file:line) to muzzle")                       \
1441                                                                             \
1442   develop(intx, StackPrintLimit, 100,                                       \
1443           "number of stack frames to print in VM-level stack dump")         \
1444                                                                             \
1445   notproduct(intx, MaxElementPrintSize, 256,                                \
1446           "maximum number of elements to print")                            \
1447                                                                             \
1448   notproduct(intx, MaxSubklassPrintSize, 4,                                 \
1449           "maximum number of subklasses to print when printing klass")      \
1450                                                                             \
1451   product(intx, MaxInlineLevel, 15,                                         \
1452           "maximum number of nested calls that are inlined")                \
1453           range(0, max_jint)                                                \
1454                                                                             \
1455   product(intx, MaxRecursiveInlineLevel, 1,                                 \
1456           "maximum number of nested recursive calls that are inlined")      \
1457           range(0, max_jint)                                                \
1458                                                                             \
1459   develop(intx, MaxForceInlineLevel, 100,                                   \
1460           "maximum number of nested calls that are forced for inlining "    \
1461           "(using CompileCommand or marked w/ @ForceInline)")               \
1462           range(0, max_jint)                                                \
1463                                                                             \
1464   product_pd(intx, InlineSmallCode,                                         \
1465           "Only inline already compiled methods if their code size is "     \
1466           "less than this")                                                 \
1467           range(0, max_jint)                                                \
1468                                                                             \
1469   product(intx, MaxInlineSize, 35,                                          \
1470           "The maximum bytecode size of a method to be inlined")            \
1471           range(0, max_jint)                                                \
1472                                                                             \
1473   product_pd(intx, FreqInlineSize,                                          \
1474           "The maximum bytecode size of a frequent method to be inlined")   \
1475           range(0, max_jint)                                                \
1476                                                                             \
1477   product(intx, MaxTrivialSize, 6,                                          \
1478           "The maximum bytecode size of a trivial method to be inlined")    \
1479           range(0, max_jint)                                                \
1480                                                                             \
1481   product(intx, MinInliningThreshold, 250,                                  \
1482           "The minimum invocation count a method needs to have to be "      \
1483           "inlined")                                                        \
1484           range(0, max_jint)                                                \
1485                                                                             \
1486   develop(intx, MethodHistogramCutoff, 100,                                 \
1487           "The cutoff value for method invocation histogram (+CountCalls)") \
1488                                                                             \
1489   develop(intx, DontYieldALotInterval,    10,                               \
1490           "Interval between which yields will be dropped (milliseconds)")   \
1491                                                                             \
1492   notproduct(intx, DeoptimizeALotInterval,     5,                           \
1493           "Number of exits until DeoptimizeALot kicks in")                  \
1494                                                                             \
1495   notproduct(intx, ZombieALotInterval,     5,                               \
1496           "Number of exits until ZombieALot kicks in")                      \
1497                                                                             \
1498   diagnostic(uintx, MallocMaxTestWords,     0,                              \
1499           "If non-zero, maximum number of words that malloc/realloc can "   \
1500           "allocate (for testing only)")                                    \
1501           range(0, max_uintx)                                               \
1502                                                                             \
1503   product(intx, TypeProfileWidth, 2,                                        \
1504           "Number of receiver types to record in call/cast profile")        \
1505           range(0, 8)                                                       \
1506                                                                             \
1507   develop(intx, BciProfileWidth,      2,                                    \
1508           "Number of return bci's to record in ret profile")                \
1509                                                                             \
1510   product(intx, PerMethodRecompilationCutoff, 400,                          \
1511           "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1512           range(-1, max_intx)                                               \
1513                                                                             \
1514   product(intx, PerBytecodeRecompilationCutoff, 200,                        \
1515           "Per-BCI limit on repeated recompilation (-1=>'Inf')")            \
1516           range(-1, max_intx)                                               \
1517                                                                             \
1518   product(intx, PerMethodTrapLimit,  100,                                   \
1519           "Limit on traps (of one kind) in a method (includes inlines)")    \
1520           range(0, max_jint)                                                \
1521                                                                             \
1522   experimental(intx, PerMethodSpecTrapLimit,  5000,                         \
1523           "Limit on speculative traps (of one kind) in a method "           \
1524           "(includes inlines)")                                             \
1525           range(0, max_jint)                                                \
1526                                                                             \
1527   product(intx, PerBytecodeTrapLimit,  4,                                   \
1528           "Limit on traps (of one kind) at a particular BCI")               \
1529           range(0, max_jint)                                                \
1530                                                                             \
1531   experimental(intx, SpecTrapLimitExtraEntries,  3,                         \
1532           "Extra method data trap entries for speculation")                 \
1533                                                                             \
1534   develop(intx, InlineFrequencyRatio,    20,                                \
1535           "Ratio of call site execution to caller method invocation")       \
1536           range(0, max_jint)                                                \
1537                                                                             \
1538   diagnostic_pd(intx, InlineFrequencyCount,                                 \
1539           "Count of call site execution necessary to trigger frequent "     \
1540           "inlining")                                                       \
1541           range(0, max_jint)                                                \
1542                                                                             \
1543   develop(intx, InlineThrowCount,    50,                                    \
1544           "Force inlining of interpreted methods that throw this often")    \
1545           range(0, max_jint)                                                \
1546                                                                             \
1547   develop(intx, InlineThrowMaxSize,   200,                                  \
1548           "Force inlining of throwing methods smaller than this")           \
1549           range(0, max_jint)                                                \
1550                                                                             \
1551   develop(intx, ProfilerNodeSize,  1024,                                    \
1552           "Size in K to allocate for the Profile Nodes of each thread")     \
1553           range(0, 1024)                                                    \
1554                                                                             \
1555   product_pd(size_t, MetaspaceSize,                                         \
1556           "Initial threshold (in bytes) at which a garbage collection "     \
1557           "is done to reduce Metaspace usage")                              \
1558           constraint(MetaspaceSizeConstraintFunc,AfterErgo)                 \
1559                                                                             \
1560   product(size_t, MaxMetaspaceSize, max_uintx,                              \
1561           "Maximum size of Metaspaces (in bytes)")                          \
1562           constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo)              \
1563                                                                             \
1564   product(size_t, CompressedClassSpaceSize, 1*G,                            \
1565           "Maximum size of class area in Metaspace when compressed "        \
1566           "class pointers are used")                                        \
1567           range(1*M, 3*G)                                                   \
1568                                                                             \
1569   manageable(uintx, MinHeapFreeRatio, 40,                                   \
1570           "The minimum percentage of heap free after GC to avoid expansion."\
1571           " For most GCs this applies to the old generation. In G1 and"     \
1572           " ParallelGC it applies to the whole heap.")                      \
1573           range(0, 100)                                                     \
1574           constraint(MinHeapFreeRatioConstraintFunc,AfterErgo)              \
1575                                                                             \
1576   manageable(uintx, MaxHeapFreeRatio, 70,                                   \
1577           "The maximum percentage of heap free after GC to avoid shrinking."\
1578           " For most GCs this applies to the old generation. In G1 and"     \
1579           " ParallelGC it applies to the whole heap.")                      \
1580           range(0, 100)                                                     \
1581           constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo)              \
1582                                                                             \
1583   product(bool, ShrinkHeapInSteps, true,                                    \
1584           "When disabled, informs the GC to shrink the java heap directly"  \
1585           " to the target size at the next full GC rather than requiring"   \
1586           " smaller steps during multiple full GCs.")                       \
1587                                                                             \
1588   product(intx, SoftRefLRUPolicyMSPerMB, 1000,                              \
1589           "Number of milliseconds per MB of free space in the heap")        \
1590           range(0, max_intx)                                                \
1591           constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1592                                                                             \
1593   product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K),               \
1594           "The minimum change in heap space due to GC (in bytes)")          \
1595           range(0, max_uintx)                                               \
1596                                                                             \
1597   product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K),           \
1598           "The minimum expansion of Metaspace (in bytes)")                  \
1599           range(0, max_uintx)                                               \
1600                                                                             \
1601   product(uintx, MaxMetaspaceFreeRatio,    70,                              \
1602           "The maximum percentage of Metaspace free after GC to avoid "     \
1603           "shrinking")                                                      \
1604           range(0, 100)                                                     \
1605           constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo)         \
1606                                                                             \
1607   product(uintx, MinMetaspaceFreeRatio,    40,                              \
1608           "The minimum percentage of Metaspace free after GC to avoid "     \
1609           "expansion")                                                      \
1610           range(0, 99)                                                      \
1611           constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo)         \
1612                                                                             \
1613   product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M),             \
1614           "The maximum expansion of Metaspace without full GC (in bytes)")  \
1615           range(0, max_uintx)                                               \
1616                                                                             \
1617   /* stack parameters */                                                    \
1618   product_pd(intx, StackYellowPages,                                        \
1619           "Number of yellow zone (recoverable overflows) pages of size "    \
1620           "4KB. If pages are bigger yellow zone is aligned up.")            \
1621           range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5))     \
1622                                                                             \
1623   product_pd(intx, StackRedPages,                                           \
1624           "Number of red zone (unrecoverable overflows) pages of size "     \
1625           "4KB. If pages are bigger red zone is aligned up.")               \
1626           range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2))           \
1627                                                                             \
1628   product_pd(intx, StackReservedPages,                                      \
1629           "Number of reserved zone (reserved to annotated methods) pages"   \
1630           " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1631           range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1632                                                                             \
1633   product(bool, RestrictReservedStack, true,                                \
1634           "Restrict @ReservedStackAccess to trusted classes")               \
1635                                                                             \
1636   /* greater stack shadow pages can't generate instruction to bang stack */ \
1637   product_pd(intx, StackShadowPages,                                        \
1638           "Number of shadow zone (for overflow checking) pages of size "    \
1639           "4KB. If pages are bigger shadow zone is aligned up. "            \
1640           "This should exceed the depth of the VM and native call stack.")  \
1641           range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30))    \
1642                                                                             \
1643   product_pd(intx, ThreadStackSize,                                         \
1644           "Thread Stack Size (in Kbytes)")                                  \
1645           range(0, 1 * M)                                                   \
1646                                                                             \
1647   product_pd(intx, VMThreadStackSize,                                       \
1648           "Non-Java Thread Stack Size (in Kbytes)")                         \
1649           range(0, max_intx/(1 * K))                                        \
1650                                                                             \
1651   product_pd(intx, CompilerThreadStackSize,                                 \
1652           "Compiler Thread Stack Size (in Kbytes)")                         \
1653           range(0, max_intx/(1 * K))                                        \
1654                                                                             \
1655   develop_pd(size_t, JVMInvokeMethodSlack,                                  \
1656           "Stack space (bytes) required for JVM_InvokeMethod to complete")  \
1657                                                                             \
1658   /* code cache parameters                                    */            \
1659   develop_pd(uintx, CodeCacheSegmentSize,                                   \
1660           "Code cache segment size (in bytes) - smallest unit of "          \
1661           "allocation")                                                     \
1662           range(1, 1024)                                                    \
1663           constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo)         \
1664                                                                             \
1665   develop_pd(intx, CodeEntryAlignment,                                      \
1666           "Code entry alignment for generated code (in bytes)")             \
1667           constraint(CodeEntryAlignmentConstraintFunc, AfterErgo)           \
1668                                                                             \
1669   product_pd(intx, OptoLoopAlignment,                                       \
1670           "Align inner loops to zero relative to this modulus")             \
1671           range(1, 16)                                                      \
1672           constraint(OptoLoopAlignmentConstraintFunc, AfterErgo)            \
1673                                                                             \
1674   product_pd(uintx, InitialCodeCacheSize,                                   \
1675           "Initial code cache size (in bytes)")                             \
1676           range(os::vm_page_size(), max_uintx)                              \
1677                                                                             \
1678   develop_pd(uintx, CodeCacheMinimumUseSpace,                               \
1679           "Minimum code cache size (in bytes) required to start VM.")       \
1680           range(0, max_uintx)                                               \
1681                                                                             \
1682   product(bool, SegmentedCodeCache, false,                                  \
1683           "Use a segmented code cache")                                     \
1684                                                                             \
1685   product_pd(uintx, ReservedCodeCacheSize,                                  \
1686           "Reserved code cache size (in bytes) - maximum code cache size")  \
1687           range(os::vm_page_size(), max_uintx)                              \
1688                                                                             \
1689   product_pd(uintx, NonProfiledCodeHeapSize,                                \
1690           "Size of code heap with non-profiled methods (in bytes)")         \
1691           range(0, max_uintx)                                               \
1692                                                                             \
1693   product_pd(uintx, ProfiledCodeHeapSize,                                   \
1694           "Size of code heap with profiled methods (in bytes)")             \
1695           range(0, max_uintx)                                               \
1696                                                                             \
1697   product_pd(uintx, NonNMethodCodeHeapSize,                                 \
1698           "Size of code heap with non-nmethods (in bytes)")                 \
1699           range(os::vm_page_size(), max_uintx)                              \
1700                                                                             \
1701   product_pd(uintx, CodeCacheExpansionSize,                                 \
1702           "Code cache expansion size (in bytes)")                           \
1703           range(32*K, max_uintx)                                            \
1704                                                                             \
1705   diagnostic_pd(uintx, CodeCacheMinBlockLength,                             \
1706           "Minimum number of segments in a code cache block")               \
1707           range(1, 100)                                                     \
1708                                                                             \
1709   notproduct(bool, ExitOnFullCodeCache, false,                              \
1710           "Exit the VM if we fill the code cache")                          \
1711                                                                             \
1712   product(bool, UseCodeCacheFlushing, true,                                 \
1713           "Remove cold/old nmethods from the code cache")                   \
1714                                                                             \
1715   product(uintx, StartAggressiveSweepingAt, 10,                             \
1716           "Start aggressive sweeping if X[%] of the code cache is free."    \
1717           "Segmented code cache: X[%] of the non-profiled heap."            \
1718           "Non-segmented code cache: X[%] of the total code cache")         \
1719           range(0, 100)                                                     \
1720                                                                             \
1721   /* AOT parameters */                                                      \
1722   experimental(bool, UseAOT, false,                                         \
1723           "Use AOT compiled files")                                         \
1724                                                                             \
1725   experimental(ccstrlist, AOTLibrary, NULL,                                 \
1726           "AOT library")                                                    \
1727                                                                             \
1728   experimental(bool, PrintAOT, false,                                       \
1729           "Print used AOT klasses and methods")                             \
1730                                                                             \
1731   notproduct(bool, PrintAOTStatistics, false,                               \
1732           "Print AOT statistics")                                           \
1733                                                                             \
1734   diagnostic(bool, UseAOTStrictLoading, false,                              \
1735           "Exit the VM if any of the AOT libraries has invalid config")     \
1736                                                                             \
1737   product(bool, CalculateClassFingerprint, false,                           \
1738           "Calculate class fingerprint")                                    \
1739                                                                             \
1740   /* interpreter debugging */                                               \
1741   develop(intx, BinarySwitchThreshold, 5,                                   \
1742           "Minimal number of lookupswitch entries for rewriting to binary " \
1743           "switch")                                                         \
1744                                                                             \
1745   develop(intx, StopInterpreterAt, 0,                                       \
1746           "Stop interpreter execution at specified bytecode number")        \
1747                                                                             \
1748   develop(intx, TraceBytecodesAt, 0,                                        \
1749           "Trace bytecodes starting with specified bytecode number")        \
1750                                                                             \
1751   /* compiler interface */                                                  \
1752   develop(intx, CIStart, 0,                                                 \
1753           "The id of the first compilation to permit")                      \
1754                                                                             \
1755   develop(intx, CIStop, max_jint,                                           \
1756           "The id of the last compilation to permit")                       \
1757                                                                             \
1758   develop(intx, CIStartOSR, 0,                                              \
1759           "The id of the first osr compilation to permit "                  \
1760           "(CICountOSR must be on)")                                        \
1761                                                                             \
1762   develop(intx, CIStopOSR, max_jint,                                        \
1763           "The id of the last osr compilation to permit "                   \
1764           "(CICountOSR must be on)")                                        \
1765                                                                             \
1766   develop(intx, CIBreakAtOSR, -1,                                           \
1767           "The id of osr compilation to break at")                          \
1768                                                                             \
1769   develop(intx, CIBreakAt, -1,                                              \
1770           "The id of compilation to break at")                              \
1771                                                                             \
1772   product(ccstrlist, CompileOnly, "",                                       \
1773           "List of methods (pkg/class.name) to restrict compilation to")    \
1774                                                                             \
1775   product(ccstr, CompileCommandFile, NULL,                                  \
1776           "Read compiler commands from this file [.hotspot_compiler]")      \
1777                                                                             \
1778   diagnostic(ccstr, CompilerDirectivesFile, NULL,                           \
1779           "Read compiler directives from this file")                        \
1780                                                                             \
1781   product(ccstrlist, CompileCommand, "",                                    \
1782           "Prepend to .hotspot_compiler; e.g. log,java/lang/String.<init>") \
1783                                                                             \
1784   develop(bool, ReplayCompiles, false,                                      \
1785           "Enable replay of compilations from ReplayDataFile")              \
1786                                                                             \
1787   product(ccstr, ReplayDataFile, NULL,                                      \
1788           "File containing compilation replay information"                  \
1789           "[default: ./replay_pid%p.log] (%p replaced with pid)")           \
1790                                                                             \
1791    product(ccstr, InlineDataFile, NULL,                                     \
1792           "File containing inlining replay information"                     \
1793           "[default: ./inline_pid%p.log] (%p replaced with pid)")           \
1794                                                                             \
1795   develop(intx, ReplaySuppressInitializers, 2,                              \
1796           "Control handling of class initialization during replay: "        \
1797           "0 - don't do anything special; "                                 \
1798           "1 - treat all class initializers as empty; "                     \
1799           "2 - treat class initializers for application classes as empty; " \
1800           "3 - allow all class initializers to run during bootstrap but "   \
1801           "    pretend they are empty after starting replay")               \
1802           range(0, 3)                                                       \
1803                                                                             \
1804   develop(bool, ReplayIgnoreInitErrors, false,                              \
1805           "Ignore exceptions thrown during initialization for replay")      \
1806                                                                             \
1807   product(bool, DumpReplayDataOnError, true,                                \
1808           "Record replay data for crashing compiler threads")               \
1809                                                                             \
1810   product(bool, CICompilerCountPerCPU, false,                               \
1811           "1 compiler thread for log(N CPUs)")                              \
1812                                                                             \
1813   notproduct(intx, CICrashAt, -1,                                           \
1814           "id of compilation to trigger assert in compiler thread for "     \
1815           "the purpose of testing, e.g. generation of replay data")         \
1816   notproduct(bool, CIObjectFactoryVerify, false,                            \
1817           "enable potentially expensive verification in ciObjectFactory")   \
1818                                                                             \
1819   diagnostic(bool, AbortVMOnCompilationFailure, false,                      \
1820           "Abort VM when method had failed to compile.")                    \
1821                                                                             \
1822   /* Priorities */                                                          \
1823   product_pd(bool, UseThreadPriorities,  "Use native thread priorities")    \
1824                                                                             \
1825   product(intx, ThreadPriorityPolicy, 0,                                    \
1826           "0 : Normal.                                                     "\
1827           "    VM chooses priorities that are appropriate for normal       "\
1828           "    applications.                                               "\
1829           "    On Windows applications are allowed to use higher native    "\
1830           "    priorities. However, with ThreadPriorityPolicy=0, VM will   "\
1831           "    not use the highest possible native priority,               "\
1832           "    THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with     "\
1833           "    system threads. On Linux thread priorities are ignored      "\
1834           "    because the OS does not support static priority in          "\
1835           "    SCHED_OTHER scheduling class which is the only choice for   "\
1836           "    non-root, non-realtime applications.                        "\
1837           "1 : Aggressive.                                                 "\
1838           "    Java thread priorities map over to the entire range of      "\
1839           "    native thread priorities. Higher Java thread priorities map "\
1840           "    to higher native thread priorities. This policy should be   "\
1841           "    used with care, as sometimes it can cause performance       "\
1842           "    degradation in the application and/or the entire system. On "\
1843           "    Linux/BSD/macOS this policy requires root privilege or an   "\
1844           "    extended capability.")                                       \
1845           range(0, 1)                                                       \
1846                                                                             \
1847   product(bool, ThreadPriorityVerbose, false,                               \
1848           "Print priority changes")                                         \
1849                                                                             \
1850   product(intx, CompilerThreadPriority, -1,                                 \
1851           "The native priority at which compiler threads should run "       \
1852           "(-1 means no change)")                                           \
1853           range(min_jint, max_jint)                                         \
1854           constraint(CompilerThreadPriorityConstraintFunc, AfterErgo)       \
1855                                                                             \
1856   product(intx, VMThreadPriority, -1,                                       \
1857           "The native priority at which the VM thread should run "          \
1858           "(-1 means no change)")                                           \
1859           range(-1, 127)                                                    \
1860                                                                             \
1861   product(intx, JavaPriority1_To_OSPriority, -1,                            \
1862           "Map Java priorities to OS priorities")                           \
1863           range(-1, 127)                                                    \
1864                                                                             \
1865   product(intx, JavaPriority2_To_OSPriority, -1,                            \
1866           "Map Java priorities to OS priorities")                           \
1867           range(-1, 127)                                                    \
1868                                                                             \
1869   product(intx, JavaPriority3_To_OSPriority, -1,                            \
1870           "Map Java priorities to OS priorities")                           \
1871           range(-1, 127)                                                    \
1872                                                                             \
1873   product(intx, JavaPriority4_To_OSPriority, -1,                            \
1874           "Map Java priorities to OS priorities")                           \
1875           range(-1, 127)                                                    \
1876                                                                             \
1877   product(intx, JavaPriority5_To_OSPriority, -1,                            \
1878           "Map Java priorities to OS priorities")                           \
1879           range(-1, 127)                                                    \
1880                                                                             \
1881   product(intx, JavaPriority6_To_OSPriority, -1,                            \
1882           "Map Java priorities to OS priorities")                           \
1883           range(-1, 127)                                                    \
1884                                                                             \
1885   product(intx, JavaPriority7_To_OSPriority, -1,                            \
1886           "Map Java priorities to OS priorities")                           \
1887           range(-1, 127)                                                    \
1888                                                                             \
1889   product(intx, JavaPriority8_To_OSPriority, -1,                            \
1890           "Map Java priorities to OS priorities")                           \
1891           range(-1, 127)                                                    \
1892                                                                             \
1893   product(intx, JavaPriority9_To_OSPriority, -1,                            \
1894           "Map Java priorities to OS priorities")                           \
1895           range(-1, 127)                                                    \
1896                                                                             \
1897   product(intx, JavaPriority10_To_OSPriority,-1,                            \
1898           "Map Java priorities to OS priorities")                           \
1899           range(-1, 127)                                                    \
1900                                                                             \
1901   experimental(bool, UseCriticalJavaThreadPriority, false,                  \
1902           "Java thread priority 10 maps to critical scheduling priority")   \
1903                                                                             \
1904   experimental(bool, UseCriticalCompilerThreadPriority, false,              \
1905           "Compiler thread(s) run at critical scheduling priority")         \
1906                                                                             \
1907   develop(intx, NewCodeParameter,      0,                                   \
1908           "Testing Only: Create a dedicated integer parameter before "      \
1909           "putback")                                                        \
1910                                                                             \
1911   /* new oopmap storage allocation */                                       \
1912   develop(intx, MinOopMapAllocation,     8,                                 \
1913           "Minimum number of OopMap entries in an OopMapSet")               \
1914                                                                             \
1915   /* Background Compilation */                                              \
1916   develop(intx, LongCompileThreshold,     50,                               \
1917           "Used with +TraceLongCompiles")                                   \
1918                                                                             \
1919   /* recompilation */                                                       \
1920   product_pd(intx, CompileThreshold,                                        \
1921           "number of interpreted method invocations before (re-)compiling") \
1922           constraint(CompileThresholdConstraintFunc, AfterErgo)             \
1923                                                                             \
1924   product(double, CompileThresholdScaling, 1.0,                             \
1925           "Factor to control when first compilation happens "               \
1926           "(both with and without tiered compilation): "                    \
1927           "values greater than 1.0 delay counter overflow, "                \
1928           "values between 0 and 1.0 rush counter overflow, "                \
1929           "value of 1.0 leaves compilation thresholds unchanged "           \
1930           "value of 0.0 is equivalent to -Xint. "                           \
1931           ""                                                                \
1932           "Flag can be set as per-method option. "                          \
1933           "If a value is specified for a method, compilation thresholds "   \
1934           "for that method are scaled by both the value of the global flag "\
1935           "and the value of the per-method flag.")                          \
1936           range(0.0, DBL_MAX)                                               \
1937                                                                             \
1938   product(intx, Tier0InvokeNotifyFreqLog, 7,                                \
1939           "Interpreter (tier 0) invocation notification frequency")         \
1940           range(0, 30)                                                      \
1941                                                                             \
1942   product(intx, Tier2InvokeNotifyFreqLog, 11,                               \
1943           "C1 without MDO (tier 2) invocation notification frequency")      \
1944           range(0, 30)                                                      \
1945                                                                             \
1946   product(intx, Tier3InvokeNotifyFreqLog, 10,                               \
1947           "C1 with MDO profiling (tier 3) invocation notification "         \
1948           "frequency")                                                      \
1949           range(0, 30)                                                      \
1950                                                                             \
1951   product(intx, Tier23InlineeNotifyFreqLog, 20,                             \
1952           "Inlinee invocation (tiers 2 and 3) notification frequency")      \
1953           range(0, 30)                                                      \
1954                                                                             \
1955   product(intx, Tier0BackedgeNotifyFreqLog, 10,                             \
1956           "Interpreter (tier 0) invocation notification frequency")         \
1957           range(0, 30)                                                      \
1958                                                                             \
1959   product(intx, Tier2BackedgeNotifyFreqLog, 14,                             \
1960           "C1 without MDO (tier 2) invocation notification frequency")      \
1961           range(0, 30)                                                      \
1962                                                                             \
1963   product(intx, Tier3BackedgeNotifyFreqLog, 13,                             \
1964           "C1 with MDO profiling (tier 3) invocation notification "         \
1965           "frequency")                                                      \
1966           range(0, 30)                                                      \
1967                                                                             \
1968   product(intx, Tier2CompileThreshold, 0,                                   \
1969           "threshold at which tier 2 compilation is invoked")               \
1970           range(0, max_jint)                                                \
1971                                                                             \
1972   product(intx, Tier2BackEdgeThreshold, 0,                                  \
1973           "Back edge threshold at which tier 2 compilation is invoked")     \
1974           range(0, max_jint)                                                \
1975                                                                             \
1976   product(intx, Tier3InvocationThreshold, 200,                              \
1977           "Compile if number of method invocations crosses this "           \
1978           "threshold")                                                      \
1979           range(0, max_jint)                                                \
1980                                                                             \
1981   product(intx, Tier3MinInvocationThreshold, 100,                           \
1982           "Minimum invocation to compile at tier 3")                        \
1983           range(0, max_jint)                                                \
1984                                                                             \
1985   product(intx, Tier3CompileThreshold, 2000,                                \
1986           "Threshold at which tier 3 compilation is invoked (invocation "   \
1987           "minimum must be satisfied)")                                     \
1988           range(0, max_jint)                                                \
1989                                                                             \
1990   product(intx, Tier3BackEdgeThreshold,  60000,                             \
1991           "Back edge threshold at which tier 3 OSR compilation is invoked") \
1992           range(0, max_jint)                                                \
1993                                                                             \
1994   product(intx, Tier3AOTInvocationThreshold, 10000,                         \
1995           "Compile if number of method invocations crosses this "           \
1996           "threshold if coming from AOT")                                   \
1997           range(0, max_jint)                                                \
1998                                                                             \
1999   product(intx, Tier3AOTMinInvocationThreshold, 1000,                       \
2000           "Minimum invocation to compile at tier 3 if coming from AOT")     \
2001           range(0, max_jint)                                                \
2002                                                                             \
2003   product(intx, Tier3AOTCompileThreshold, 15000,                            \
2004           "Threshold at which tier 3 compilation is invoked (invocation "   \
2005           "minimum must be satisfied) if coming from AOT")                  \
2006           range(0, max_jint)                                                \
2007                                                                             \
2008   product(intx, Tier3AOTBackEdgeThreshold,  120000,                         \
2009           "Back edge threshold at which tier 3 OSR compilation is invoked " \
2010           "if coming from AOT")                                             \
2011           range(0, max_jint)                                                \
2012                                                                             \
2013   diagnostic(intx, Tier0AOTInvocationThreshold, 200,                        \
2014           "Switch to interpreter to profile if the number of method "       \
2015           "invocations crosses this threshold if coming from AOT "          \
2016           "(applicable only with "                                          \
2017           "CompilationMode=high-only|high-only-quick-internal)")            \
2018           range(0, max_jint)                                                \
2019                                                                             \
2020   diagnostic(intx, Tier0AOTMinInvocationThreshold, 100,                     \
2021           "Minimum number of invocations to switch to interpreter "         \
2022           "to profile if coming from AOT "                                  \
2023           "(applicable only with "                                          \
2024           "CompilationMode=high-only|high-only-quick-internal)")            \
2025           range(0, max_jint)                                                \
2026                                                                             \
2027   diagnostic(intx, Tier0AOTCompileThreshold, 2000,                          \
2028           "Threshold at which to switch to interpreter to profile "         \
2029           "if coming from AOT "                                             \
2030           "(invocation minimum must be satisfied, "                         \
2031           "applicable only with "                                           \
2032           "CompilationMode=high-only|high-only-quick-internal)")            \
2033           range(0, max_jint)                                                \
2034                                                                             \
2035   diagnostic(intx, Tier0AOTBackEdgeThreshold,  60000,                       \
2036           "Back edge threshold at which to switch to interpreter "          \
2037           "to profile if coming from AOT "                                  \
2038           "(applicable only with "                                          \
2039           "CompilationMode=high-only|high-only-quick-internal)")            \
2040           range(0, max_jint)                                                \
2041                                                                             \
2042   product(intx, Tier4InvocationThreshold, 5000,                             \
2043           "Compile if number of method invocations crosses this "           \
2044           "threshold")                                                      \
2045           range(0, max_jint)                                                \
2046                                                                             \
2047   product(intx, Tier4MinInvocationThreshold, 600,                           \
2048           "Minimum invocation to compile at tier 4")                        \
2049           range(0, max_jint)                                                \
2050                                                                             \
2051   product(intx, Tier4CompileThreshold, 15000,                               \
2052           "Threshold at which tier 4 compilation is invoked (invocation "   \
2053           "minimum must be satisfied)")                                     \
2054           range(0, max_jint)                                                \
2055                                                                             \
2056   product(intx, Tier4BackEdgeThreshold, 40000,                              \
2057           "Back edge threshold at which tier 4 OSR compilation is invoked") \
2058           range(0, max_jint)                                                \
2059                                                                             \
2060   diagnostic(intx, Tier40InvocationThreshold, 5000,                         \
2061           "Compile if number of method invocations crosses this "           \
2062           "threshold (applicable only with "                                \
2063           "CompilationMode=high-only|high-only-quick-internal)")            \
2064           range(0, max_jint)                                                \
2065                                                                             \
2066   diagnostic(intx, Tier40MinInvocationThreshold, 600,                       \
2067           "Minimum number of invocations to compile at tier 4 "             \
2068           "(applicable only with "                                          \
2069           "CompilationMode=high-only|high-only-quick-internal)")            \
2070           range(0, max_jint)                                                \
2071                                                                             \
2072   diagnostic(intx, Tier40CompileThreshold, 10000,                           \
2073           "Threshold at which tier 4 compilation is invoked (invocation "   \
2074           "minimum must be satisfied, applicable only with "                \
2075           "CompilationMode=high-only|high-only-quick-internal)")            \
2076           range(0, max_jint)                                                \
2077                                                                             \
2078   diagnostic(intx, Tier40BackEdgeThreshold, 15000,                          \
2079           "Back edge threshold at which tier 4 OSR compilation is invoked " \
2080           "(applicable only with "                                          \
2081           "CompilationMode=high-only|high-only-quick-internal)")            \
2082           range(0, max_jint)                                                \
2083                                                                             \
2084   diagnostic(intx, Tier0Delay, 5,                                           \
2085           "If C2 queue size grows over this amount per compiler thread "    \
2086           "do not start profiling in the interpreter "                      \
2087           "(applicable only with "                                          \
2088           "CompilationMode=high-only|high-only-quick-internal)")            \
2089           range(0, max_jint)                                                \
2090                                                                             \
2091   product(intx, Tier3DelayOn, 5,                                            \
2092           "If C2 queue size grows over this amount per compiler thread "    \
2093           "stop compiling at tier 3 and start compiling at tier 2")         \
2094           range(0, max_jint)                                                \
2095                                                                             \
2096   product(intx, Tier3DelayOff, 2,                                           \
2097           "If C2 queue size is less than this amount per compiler thread "  \
2098           "allow methods compiled at tier 2 transition to tier 3")          \
2099           range(0, max_jint)                                                \
2100                                                                             \
2101   product(intx, Tier3LoadFeedback, 5,                                       \
2102           "Tier 3 thresholds will increase twofold when C1 queue size "     \
2103           "reaches this amount per compiler thread")                        \
2104           range(0, max_jint)                                                \
2105                                                                             \
2106   product(intx, Tier4LoadFeedback, 3,                                       \
2107           "Tier 4 thresholds will increase twofold when C2 queue size "     \
2108           "reaches this amount per compiler thread")                        \
2109           range(0, max_jint)                                                \
2110                                                                             \
2111   product(intx, TieredCompileTaskTimeout, 50,                               \
2112           "Kill compile task if method was not used within "                \
2113           "given timeout in milliseconds")                                  \
2114           range(0, max_intx)                                                \
2115                                                                             \
2116   product(intx, TieredStopAtLevel, 4,                                       \
2117           "Stop at given compilation level")                                \
2118           range(0, 4)                                                       \
2119                                                                             \
2120   product(intx, Tier0ProfilingStartPercentage, 200,                         \
2121           "Start profiling in interpreter if the counters exceed tier 3 "   \
2122           "thresholds (tier 4 thresholds with "                             \
2123           "CompilationMode=high-only|high-only-quick-internal)"             \
2124           "by the specified percentage")                                    \
2125           range(0, max_jint)                                                \
2126                                                                             \
2127   product(uintx, IncreaseFirstTierCompileThresholdAt, 50,                   \
2128           "Increase the compile threshold for C1 compilation if the code "  \
2129           "cache is filled by the specified percentage")                    \
2130           range(0, 99)                                                      \
2131                                                                             \
2132   product(intx, TieredRateUpdateMinTime, 1,                                 \
2133           "Minimum rate sampling interval (in milliseconds)")               \
2134           range(0, max_intx)                                                \
2135                                                                             \
2136   product(intx, TieredRateUpdateMaxTime, 25,                                \
2137           "Maximum rate sampling interval (in milliseconds)")               \
2138           range(0, max_intx)                                                \
2139                                                                             \
2140   product(ccstr, CompilationMode, "default",                                \
2141           "Compilation modes: "                                             \
2142           "default: normal tiered compilation; "                            \
2143           "quick-only: C1-only mode; "                                      \
2144           "high-only: C2/JVMCI-only mode; "                                 \
2145           "high-only-quick-internal: C2/JVMCI-only mode, "                  \
2146           "with JVMCI compiler compiled with C1.")                          \
2147                                                                             \
2148   product_pd(bool, TieredCompilation,                                       \
2149           "Enable tiered compilation")                                      \
2150                                                                             \
2151   product(bool, PrintTieredEvents, false,                                   \
2152           "Print tiered events notifications")                              \
2153                                                                             \
2154   product_pd(intx, OnStackReplacePercentage,                                \
2155           "NON_TIERED number of method invocations/branches (expressed as " \
2156           "% of CompileThreshold) before (re-)compiling OSR code")          \
2157           constraint(OnStackReplacePercentageConstraintFunc, AfterErgo)     \
2158                                                                             \
2159   product(intx, InterpreterProfilePercentage, 33,                           \
2160           "NON_TIERED number of method invocations/branches (expressed as " \
2161           "% of CompileThreshold) before profiling in the interpreter")     \
2162           range(0, 100)                                                     \
2163                                                                             \
2164   develop(intx, DesiredMethodLimit,  8000,                                  \
2165           "The desired maximum method size (in bytecodes) after inlining")  \
2166                                                                             \
2167   develop(intx, HugeMethodLimit,  8000,                                     \
2168           "Don't compile methods larger than this if "                      \
2169           "+DontCompileHugeMethods")                                        \
2170                                                                             \
2171   /* Properties for Java libraries  */                                      \
2172                                                                             \
2173   product(uint64_t, MaxDirectMemorySize, 0,                                 \
2174           "Maximum total size of NIO direct-buffer allocations")            \
2175           range(0, max_jlong)                                               \
2176                                                                             \
2177   /* Flags used for temporary code during development  */                   \
2178                                                                             \
2179   diagnostic(bool, UseNewCode, false,                                       \
2180           "Testing Only: Use the new version while testing")                \
2181                                                                             \
2182   diagnostic(bool, UseNewCode2, false,                                      \
2183           "Testing Only: Use the new version while testing")                \
2184                                                                             \
2185   diagnostic(bool, UseNewCode3, false,                                      \
2186           "Testing Only: Use the new version while testing")                \
2187                                                                             \
2188   /* flags for performance data collection */                               \
2189                                                                             \
2190   product(bool, UsePerfData, true,                                          \
2191           "Flag to disable jvmstat instrumentation for performance testing "\
2192           "and problem isolation purposes")                                 \
2193                                                                             \
2194   product(bool, PerfDataSaveToFile, false,                                  \
2195           "Save PerfData memory to hsperfdata_<pid> file on exit")          \
2196                                                                             \
2197   product(ccstr, PerfDataSaveFile, NULL,                                    \
2198           "Save PerfData memory to the specified absolute pathname. "       \
2199           "The string %p in the file name (if present) "                    \
2200           "will be replaced by pid")                                        \
2201                                                                             \
2202   product(intx, PerfDataSamplingInterval, 50,                               \
2203           "Data sampling interval (in milliseconds)")                       \
2204           range(PeriodicTask::min_interval, max_jint)                       \
2205           constraint(PerfDataSamplingIntervalFunc, AfterErgo)               \
2206                                                                             \
2207   product(bool, PerfDisableSharedMem, false,                                \
2208           "Store performance data in standard memory")                      \
2209                                                                             \
2210   product(intx, PerfDataMemorySize, 32*K,                                   \
2211           "Size of performance data memory region. Will be rounded "        \
2212           "up to a multiple of the native os page size.")                   \
2213           range(128, 32*64*K)                                               \
2214                                                                             \
2215   product(intx, PerfMaxStringConstLength, 1024,                             \
2216           "Maximum PerfStringConstant string length before truncation")     \
2217           range(32, 32*K)                                                   \
2218                                                                             \
2219   product(bool, PerfAllowAtExitRegistration, false,                         \
2220           "Allow registration of atexit() methods")                         \
2221                                                                             \
2222   product(bool, PerfBypassFileSystemCheck, false,                           \
2223           "Bypass Win32 file system criteria checks (Windows Only)")        \
2224                                                                             \
2225   product(intx, UnguardOnExecutionViolation, 0,                             \
2226           "Unguard page and retry on no-execute fault (Win32 only) "        \
2227           "0=off, 1=conservative, 2=aggressive")                            \
2228           range(0, 2)                                                       \
2229                                                                             \
2230   /* Serviceability Support */                                              \
2231                                                                             \
2232   product(bool, ManagementServer, false,                                    \
2233           "Create JMX Management Server")                                   \
2234                                                                             \
2235   product(bool, DisableAttachMechanism, false,                              \
2236           "Disable mechanism that allows tools to attach to this VM")       \
2237                                                                             \
2238   product(bool, StartAttachListener, false,                                 \
2239           "Always start Attach Listener at VM startup")                     \
2240                                                                             \
2241   product(bool, EnableDynamicAgentLoading, true,                            \
2242           "Allow tools to load agents with the attach mechanism")           \
2243                                                                             \
2244   manageable(bool, PrintConcurrentLocks, false,                             \
2245           "Print java.util.concurrent locks in thread dump")                \
2246                                                                             \
2247   /* Shared spaces */                                                       \
2248                                                                             \
2249   product(bool, UseSharedSpaces, true,                                      \
2250           "Use shared spaces for metadata")                                 \
2251                                                                             \
2252   product(bool, VerifySharedSpaces, false,                                  \
2253           "Verify integrity of shared spaces")                              \
2254                                                                             \
2255   product(bool, RequireSharedSpaces, false,                                 \
2256           "Require shared spaces for metadata")                             \
2257                                                                             \
2258   product(bool, DumpSharedSpaces, false,                                    \
2259           "Special mode: JVM reads a class list, loads classes, builds "    \
2260           "shared spaces, and dumps the shared spaces to a file to be "     \
2261           "used in future JVM runs")                                        \
2262                                                                             \
2263   product(bool, DynamicDumpSharedSpaces, false,                             \
2264           "Dynamic archive")                                                \
2265                                                                             \
2266   product(bool, PrintSharedArchiveAndExit, false,                           \
2267           "Print shared archive file contents")                             \
2268                                                                             \
2269   product(bool, PrintSharedDictionary, false,                               \
2270           "If PrintSharedArchiveAndExit is true, also print the shared "    \
2271           "dictionary")                                                     \
2272                                                                             \
2273   product(size_t, SharedBaseAddress, LP64_ONLY(32*G)                        \
2274           NOT_LP64(LINUX_ONLY(2*G) NOT_LINUX(0)),                           \
2275           "Address to allocate shared memory region for class data")        \
2276           range(0, SIZE_MAX)                                                \
2277                                                                             \
2278   product(ccstr, SharedArchiveConfigFile, NULL,                             \
2279           "Data to add to the CDS archive file")                            \
2280                                                                             \
2281   product(uintx, SharedSymbolTableBucketSize, 4,                            \
2282           "Average number of symbols per bucket in shared table")           \
2283           range(2, 246)                                                     \
2284                                                                             \
2285   diagnostic(bool, AllowArchivingWithJavaAgent, false,                      \
2286           "Allow Java agent to be run with CDS dumping")                    \
2287                                                                             \
2288   diagnostic(bool, PrintMethodHandleStubs, false,                           \
2289           "Print generated stub code for method handles")                   \
2290                                                                             \
2291   diagnostic(bool, VerifyMethodHandles, trueInDebug,                        \
2292           "perform extra checks when constructing method handles")          \
2293                                                                             \
2294   diagnostic(bool, ShowHiddenFrames, false,                                 \
2295           "show method handle implementation frames (usually hidden)")      \
2296                                                                             \
2297   experimental(bool, TrustFinalNonStaticFields, false,                      \
2298           "trust final non-static declarations for constant folding")       \
2299                                                                             \
2300   diagnostic(bool, FoldStableValues, true,                                  \
2301           "Optimize loads from stable fields (marked w/ @Stable)")          \
2302                                                                             \
2303   diagnostic(int, UseBootstrapCallInfo, 1,                                  \
2304           "0: when resolving InDy or ConDy, force all BSM arguments to be " \
2305           "resolved before the bootstrap method is called; 1: when a BSM "  \
2306           "that may accept a BootstrapCallInfo is detected, use that API "  \
2307           "to pass BSM arguments, which allows the BSM to delay their "     \
2308           "resolution; 2+: stress test the BCI API by calling more BSMs "   \
2309           "via that API, instead of with the eagerly-resolved array.")      \
2310                                                                             \
2311   diagnostic(bool, PauseAtStartup,      false,                              \
2312           "Causes the VM to pause at startup time and wait for the pause "  \
2313           "file to be removed (default: ./vm.paused.<pid>)")                \
2314                                                                             \
2315   diagnostic(ccstr, PauseAtStartupFile, NULL,                               \
2316           "The file to create and for whose removal to await when pausing " \
2317           "at startup. (default: ./vm.paused.<pid>)")                       \
2318                                                                             \
2319   diagnostic(bool, PauseAtExit, false,                                      \
2320           "Pause and wait for keypress on exit if a debugger is attached")  \
2321                                                                             \
2322   product(bool, ExtendedDTraceProbes,    false,                             \
2323           "Enable performance-impacting dtrace probes")                     \
2324                                                                             \
2325   product(bool, DTraceMethodProbes, false,                                  \
2326           "Enable dtrace probes for method-entry and method-exit")          \
2327                                                                             \
2328   product(bool, DTraceAllocProbes, false,                                   \
2329           "Enable dtrace probes for object allocation")                     \
2330                                                                             \
2331   product(bool, DTraceMonitorProbes, false,                                 \
2332           "Enable dtrace probes for monitor events")                        \
2333                                                                             \
2334   product(bool, RelaxAccessControlCheck, false,                             \
2335           "Relax the access control checks in the verifier")                \
2336                                                                             \
2337   product(uintx, StringTableSize, defaultStringTableSize,                   \
2338           "Number of buckets in the interned String table "                 \
2339           "(will be rounded to nearest higher power of 2)")                 \
2340           range(minimumStringTableSize, 16777216ul /* 2^24 */)              \
2341                                                                             \
2342   experimental(uintx, SymbolTableSize, defaultSymbolTableSize,              \
2343           "Number of buckets in the JVM internal Symbol table")             \
2344           range(minimumSymbolTableSize, 16777216ul /* 2^24 */)              \
2345                                                                             \
2346   product(bool, UseStringDeduplication, false,                              \
2347           "Use string deduplication")                                       \
2348                                                                             \
2349   product(uintx, StringDeduplicationAgeThreshold, 3,                        \
2350           "A string must reach this age (or be promoted to an old region) " \
2351           "to be considered for deduplication")                             \
2352           range(1, markWord::max_age)                                       \
2353                                                                             \
2354   diagnostic(bool, StringDeduplicationResizeALot, false,                    \
2355           "Force table resize every time the table is scanned")             \
2356                                                                             \
2357   diagnostic(bool, StringDeduplicationRehashALot, false,                    \
2358           "Force table rehash every time the table is scanned")             \
2359                                                                             \
2360   diagnostic(bool, WhiteBoxAPI, false,                                      \
2361           "Enable internal testing APIs")                                   \
2362                                                                             \
2363   experimental(intx, SurvivorAlignmentInBytes, 0,                           \
2364            "Default survivor space alignment in bytes")                     \
2365            range(8, 256)                                                    \
2366            constraint(SurvivorAlignmentInBytesConstraintFunc,AfterErgo)     \
2367                                                                             \
2368   product(ccstr, DumpLoadedClassList, NULL,                                 \
2369           "Dump the names all loaded classes, that could be stored into "   \
2370           "the CDS archive, in the specified file")                         \
2371                                                                             \
2372   product(ccstr, SharedClassListFile, NULL,                                 \
2373           "Override the default CDS class list")                            \
2374                                                                             \
2375   product(ccstr, SharedArchiveFile, NULL,                                   \
2376           "Override the default location of the CDS archive file")          \
2377                                                                             \
2378   product(ccstr, ArchiveClassesAtExit, NULL,                                \
2379           "The path and name of the dynamic archive file")                  \
2380                                                                             \
2381   product(ccstr, ExtraSharedClassListFile, NULL,                            \
2382           "Extra classlist for building the CDS archive file")              \
2383                                                                             \
2384   diagnostic(intx, ArchiveRelocationMode, 0,                                \
2385            "(0) first map at preferred address, and if "                    \
2386            "unsuccessful, map at alternative address (default); "           \
2387            "(1) always map at alternative address; "                        \
2388            "(2) always map at preferred address, and if unsuccessful, "     \
2389            "do not map the archive")                                        \
2390            range(0, 2)                                                      \
2391                                                                             \
2392   experimental(size_t, ArrayAllocatorMallocLimit,                           \
2393           (size_t)-1,                                                       \
2394           "Allocation less than this value will be allocated "              \
2395           "using malloc. Larger allocations will use mmap.")                \
2396                                                                             \
2397   experimental(bool, AlwaysAtomicAccesses, false,                           \
2398           "Accesses to all variables should always be atomic")              \
2399                                                                             \
2400   diagnostic(bool, UseUnalignedAccesses, false,                             \
2401           "Use unaligned memory accesses in Unsafe")                        \
2402                                                                             \
2403   product_pd(bool, PreserveFramePointer,                                    \
2404              "Use the FP register for holding the frame pointer "           \
2405              "and not as a general purpose register.")                      \
2406                                                                             \
2407   diagnostic(bool, CheckIntrinsics, true,                                   \
2408              "When a class C is loaded, check that "                        \
2409              "(1) all intrinsics defined by the VM for class C are present "\
2410              "in the loaded class file and are marked with the "            \
2411              "@HotSpotIntrinsicCandidate annotation, that "                 \
2412              "(2) there is an intrinsic registered for all loaded methods " \
2413              "that are annotated with the @HotSpotIntrinsicCandidate "      \
2414              "annotation, and that "                                        \
2415              "(3) no orphan methods exist for class C (i.e., methods for "  \
2416              "which the VM declares an intrinsic but that are not declared "\
2417              "in the loaded class C. "                                      \
2418              "Check (3) is available only in debug builds.")                \
2419                                                                             \
2420   diagnostic_pd(intx, InitArrayShortSize,                                   \
2421           "Threshold small size (in bytes) for clearing arrays. "           \
2422           "Anything this size or smaller may get converted to discrete "    \
2423           "scalar stores.")                                                 \
2424           range(0, max_intx)                                                \
2425           constraint(InitArrayShortSizeConstraintFunc, AfterErgo)           \
2426                                                                             \
2427   diagnostic(bool, CompilerDirectivesIgnoreCompileCommands, false,          \
2428              "Disable backwards compatibility for compile commands.")       \
2429                                                                             \
2430   diagnostic(bool, CompilerDirectivesPrint, false,                          \
2431              "Print compiler directives on installation.")                  \
2432   diagnostic(int,  CompilerDirectivesLimit, 50,                             \
2433              "Limit on number of compiler directives.")                     \
2434                                                                             \
2435   product(ccstr, AllocateHeapAt, NULL,                                      \
2436           "Path to the directoy where a temporary file will be created "    \
2437           "to use as the backing store for Java Heap.")                     \
2438                                                                             \
2439   experimental(ccstr, AllocateOldGenAt, NULL,                               \
2440           "Path to the directoy where a temporary file will be "            \
2441           "created to use as the backing store for old generation."         \
2442           "File of size Xmx is pre-allocated for performance reason, so"    \
2443           "we need that much space available")                              \
2444                                                                             \
2445   develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0),       \
2446                "Run periodic metaspace verifications (0 - none, "           \
2447                "1 - always, >1 every nth interval)")                        \
2448                                                                             \
2449   diagnostic(bool, ShowRegistersOnAssert, true,                             \
2450           "On internal errors, include registers in error report.")         \
2451                                                                             \
2452   diagnostic(bool, UseSwitchProfiling, true,                                \
2453           "leverage profiling for table/lookup switch")                     \
2454                                                                             \
2455   develop(bool, TraceMemoryWriteback, false,                                \
2456           "Trace memory writeback operations")                              \
2457                                                                             \
2458   JFR_ONLY(product(bool, FlightRecorder, false,                             \
2459           "(Deprecated) Enable Flight Recorder"))                           \
2460                                                                             \
2461   JFR_ONLY(product(ccstr, FlightRecorderOptions, NULL,                      \
2462           "Flight Recorder options"))                                       \
2463                                                                             \
2464   JFR_ONLY(product(ccstr, StartFlightRecording, NULL,                       \
2465           "Start flight recording with options"))                           \
2466                                                                             \
2467   experimental(bool, UseFastUnorderedTimeStamps, false,                     \
2468           "Use platform unstable time where supported for timestamps only") \
2469                                                                             \
2470   product(bool, UseNewFieldLayout, true,                                    \
2471                "(Deprecated) Use new algorithm to compute field layouts")   \
2472                                                                             \
2473   product(bool, UseEmptySlotsInSupers, true,                                \
2474                 "Allow allocating fields in empty slots of super-classes")  \
2475                                                                             \
2476   diagnostic(bool, DeoptimizeNMethodBarriersALot, false,                    \
2477                 "Make nmethod barriers deoptimise a lot.")                  \
2478 
2479 // Interface macros
2480 #define DECLARE_PRODUCT_FLAG(type, name, value, doc)      extern "C" type name;
2481 #define DECLARE_PD_PRODUCT_FLAG(type, name, doc)          extern "C" type name;
2482 #define DECLARE_DIAGNOSTIC_FLAG(type, name, value, doc)   extern "C" type name;
2483 #define DECLARE_PD_DIAGNOSTIC_FLAG(type, name, doc)       extern "C" type name;
2484 #define DECLARE_EXPERIMENTAL_FLAG(type, name, value, doc) extern "C" type name;
2485 #define DECLARE_MANAGEABLE_FLAG(type, name, value, doc)   extern "C" type name;
2486 #define DECLARE_PRODUCT_RW_FLAG(type, name, value, doc)   extern "C" type name;
2487 #ifdef PRODUCT
2488 #define DECLARE_DEVELOPER_FLAG(type, name, value, doc)    const type name = value;
2489 #define DECLARE_PD_DEVELOPER_FLAG(type, name, doc)        const type name = pd_##name;
2490 #define DECLARE_NOTPRODUCT_FLAG(type, name, value, doc)   const type name = value;
2491 #else
2492 #define DECLARE_DEVELOPER_FLAG(type, name, value, doc)    extern "C" type name;
2493 #define DECLARE_PD_DEVELOPER_FLAG(type, name, doc)        extern "C" type name;
2494 #define DECLARE_NOTPRODUCT_FLAG(type, name, value, doc)   extern "C" type name;
2495 #endif // PRODUCT
2496 // Special LP64 flags, product only needed for now.
2497 #ifdef _LP64
2498 #define DECLARE_LP64_PRODUCT_FLAG(type, name, value, doc) extern "C" type name;
2499 #else
2500 #define DECLARE_LP64_PRODUCT_FLAG(type, name, value, doc) const type name = value;
2501 #endif // _LP64
2502 
2503 ALL_FLAGS(DECLARE_DEVELOPER_FLAG,     \
2504           DECLARE_PD_DEVELOPER_FLAG,  \
2505           DECLARE_PRODUCT_FLAG,       \
2506           DECLARE_PD_PRODUCT_FLAG,    \
2507           DECLARE_DIAGNOSTIC_FLAG,    \
2508           DECLARE_PD_DIAGNOSTIC_FLAG, \
2509           DECLARE_EXPERIMENTAL_FLAG,  \
2510           DECLARE_NOTPRODUCT_FLAG,    \
2511           DECLARE_MANAGEABLE_FLAG,    \
2512           DECLARE_PRODUCT_RW_FLAG,    \
2513           DECLARE_LP64_PRODUCT_FLAG,  \
2514           IGNORE_RANGE,               \
2515           IGNORE_CONSTRAINT)
2516 
2517 #endif // SHARE_RUNTIME_GLOBALS_HPP