1 /*
2 * Copyright (c) 1997, 2024, 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,
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23 */
24
25 #ifndef SHARE_RUNTIME_GLOBALS_HPP
26 #define SHARE_RUNTIME_GLOBALS_HPP
27
28 #include "compiler/compiler_globals_pd.hpp"
29 #include "runtime/globals_shared.hpp"
30 #include "utilities/align.hpp"
31 #include "utilities/globalDefinitions.hpp"
32 #include "utilities/macros.hpp"
33 #include CPU_HEADER(globals)
34 #include OS_HEADER(globals)
35 #include OS_CPU_HEADER(globals)
36
37 // develop flags are settable / visible only during development and are constant in the PRODUCT version
38 // product flags are always settable / visible
39 // develop_pd/product_pd flags are the same as develop/product, except that their default values
40 // are specified in platform-dependent header files.
41
42 // Flags must be declared with the following number of parameters:
43 // non-pd flags:
44 // (type, name, default_value, doc), or
45 // (type, name, default_value, extra_attrs, doc)
46 // pd flags:
47 // (type, name, doc), or
48 // (type, name, extra_attrs, doc)
49
50 // A flag must be declared with one of the following types:
51 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t.
52 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used
53 // only in this file, because the macrology requires single-token type names.
54
55 // The optional extra_attrs parameter may have one of the following values:
56 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used
57 // only with product/product_pd flags.
58 //
59 // DIAGNOSTIC options are not meant for VM tuning or for product modes.
60 // They are to be used for VM quality assurance or field diagnosis
61 // of VM bugs. They are hidden so that users will not be encouraged to
62 // try them as if they were VM ordinary execution options. However, they
63 // are available in the product version of the VM. Under instruction
64 // from support engineers, VM customers can turn them on to collect
65 // diagnostic information about VM problems. To use a VM diagnostic
66 // option, you must first specify +UnlockDiagnosticVMOptions.
67 // (This master switch also affects the behavior of -Xprintflags.)
68 //
69 // EXPERIMENTAL flags are in support of features that may not be
70 // an officially supported part of a product, but may be available
71 // for experimenting with. They could, for example, be performance
72 // features that may not have undergone full or rigorous QA, but which may
73 // help performance in some cases and released for experimentation
74 // by the community of users and developers. This flag also allows one to
75 // be able to build a fully supported product that nonetheless also
76 // ships with some unsupported, lightly tested, experimental features.
77 // Refer to the documentation of any products using this code for details
78 // on support and fitness for production.
79 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
80 // UnlockExperimentalVMOptions flag, which allows the control and
81 // modification of the experimental flags.
82 //
83 // Nota bene: neither diagnostic nor experimental options should be used casually,
84 // Refer to the documentation of any products using this code for details.
85 //
86 // MANAGEABLE flags are writeable external product flags.
87 // They are dynamically writeable through the JDK management interface
88 // (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole.
89 // These flags are external exported interface (see CSR). The list of
90 // manageable flags can be queried programmatically through the management
91 // interface.
92 //
93 // A flag can be made as "manageable" only if
94 // - the flag is defined in a CSR request as an external exported interface.
95 // - the VM implementation supports dynamic setting of the flag.
96 // This implies that the VM must *always* query the flag variable
97 // and not reuse state related to the flag state at any given time.
98 // - you want the flag to be queried programmatically by the customers.
99 //
100
101 //
102 // range is a macro that will expand to min and max arguments for range
103 // checking code if provided - see jvmFlagLimit.hpp
104 //
105 // constraint is a macro that will expand to custom function call
106 // for constraint checking if provided - see jvmFlagLimit.hpp
107
108 // Default and minimum StringTable and SymbolTable size values
109 // Must be powers of 2
110 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536);
111 const size_t minimumStringTableSize = 128;
112 const size_t defaultSymbolTableSize = 32768; // 2^15
113 const size_t minimumSymbolTableSize = 1024;
114
115 #ifdef _LP64
116 #define LP64_RUNTIME_FLAGS(develop, \
117 develop_pd, \
118 product, \
119 product_pd, \
120 range, \
121 constraint) \
122 \
123 product(bool, UseCompressedOops, false, \
124 "Use 32-bit object references in 64-bit VM. " \
125 "lp64_product means flag is always constant in 32 bit VM") \
126 \
127 product(bool, UseCompressedClassPointers, true, \
128 "Use 32-bit class pointers in 64-bit VM. " \
129 "lp64_product means flag is always constant in 32 bit VM") \
130 \
131 product(int, ObjectAlignmentInBytes, 8, \
132 "Default object alignment in bytes, 8 is minimum") \
133 range(8, 256) \
134 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
135
136 #else
137 // !_LP64
138
139 #define LP64_RUNTIME_FLAGS(develop, \
140 develop_pd, \
141 product, \
142 product_pd, \
143 range, \
144 constraint)
145 const bool UseCompressedOops = false;
146 const bool UseCompressedClassPointers = false;
147 const int ObjectAlignmentInBytes = 8;
148
149 #endif // _LP64
150
151 #define RUNTIME_FLAGS(develop, \
152 develop_pd, \
153 product, \
154 product_pd, \
155 range, \
156 constraint) \
157 \
158 develop(bool, CheckCompressedOops, true, \
159 "Generate checks in encoding/decoding code in debug VM") \
160 \
161 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
162 "Heap allocation steps through preferred address regions to find" \
163 " where it can allocate the heap. Number of steps to take per " \
164 "region.") \
165 range(1, max_uintx) \
166 \
167 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
168 "If nonzero set a timeout in milliseconds for handshakes") \
169 \
170 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
171 "Force safe construction, as if all fields are final.") \
172 \
173 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
174 "Enable normal processing of flags relating to field diagnostics")\
175 \
176 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
177 "Enable normal processing of flags relating to experimental " \
178 "features") \
179 \
180 product(bool, JavaMonitorsInStackTrace, true, \
181 "Print information about Java monitor locks when the stacks are " \
182 "dumped") \
183 \
184 product_pd(bool, UseLargePages, \
185 "Use large page memory") \
186 \
187 product_pd(bool, UseLargePagesIndividualAllocation, \
188 "Allocate large pages individually for better affinity") \
189 \
190 develop(bool, LargePagesIndividualAllocationInjectError, false, \
191 "Fail large pages individual allocation") \
192 \
193 product(bool, UseNUMA, false, \
194 "Use NUMA if available") \
195 \
196 product(bool, UseNUMAInterleaving, false, \
197 "Interleave memory across NUMA nodes if available") \
198 \
199 product(size_t, NUMAInterleaveGranularity, 2*M, \
200 "Granularity to use for NUMA interleaving on Windows OS") \
201 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
202 \
203 product(uintx, NUMAChunkResizeWeight, 20, \
204 "Percentage (0-100) used to weight the current sample when " \
205 "computing exponentially decaying average for " \
206 "AdaptiveNUMAChunkSizing") \
207 range(0, 100) \
208 \
209 product(size_t, NUMASpaceResizeRate, 1*G, \
210 "Do not reallocate more than this amount per collection") \
211 range(0, max_uintx) \
212 \
213 product(bool, UseAdaptiveNUMAChunkSizing, true, \
214 "Enable adaptive chunk sizing for NUMA") \
215 \
216 product(bool, NUMAStats, false, \
217 "Print NUMA stats in detailed heap information") \
218 \
219 product(bool, UseAES, false, \
220 "Control whether AES instructions are used when available") \
221 \
222 product(bool, UseFMA, false, \
223 "Control whether FMA instructions are used when available") \
224 \
225 product(bool, UseSHA, false, \
226 "Control whether SHA instructions are used when available") \
227 \
228 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
229 "Use intrinsics for GHASH versions of crypto") \
230 \
231 product(bool, UseBASE64Intrinsics, false, \
232 "Use intrinsics for java.util.Base64") \
233 \
234 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
235 "Use intrinsics for sun.security.util.math.intpoly") \
236 \
237 product(size_t, LargePageSizeInBytes, 0, \
238 "Maximum large page size used (0 will use the default large " \
239 "page size for the environment as the maximum)") \
240 range(0, max_uintx) \
241 \
242 product(size_t, LargePageHeapSizeThreshold, 128*M, \
243 "Use large pages if maximum heap is at least this big") \
244 range(0, max_uintx) \
245 \
246 product(bool, ForceTimeHighResolution, false, \
247 "Using high time resolution (for Win32 only)") \
248 \
249 develop(bool, TracePcPatching, false, \
250 "Trace usage of frame::patch_pc") \
251 \
252 develop(bool, TraceRelocator, false, \
253 "Trace the bytecode relocator") \
254 \
255 \
256 product(bool, SafepointALot, false, DIAGNOSTIC, \
257 "Generate a lot of safepoints. This works with " \
258 "GuaranteedSafepointInterval") \
259 \
260 product(bool, HandshakeALot, false, DIAGNOSTIC, \
261 "Generate a lot of handshakes. This works with " \
262 "GuaranteedSafepointInterval") \
263 \
264 product_pd(bool, BackgroundCompilation, \
265 "A thread requesting compilation is not blocked during " \
266 "compilation") \
267 \
268 product(bool, MethodFlushing, true, \
269 "Reclamation of compiled methods") \
270 \
271 develop(bool, VerifyStack, false, \
272 "Verify stack of each thread when it is entering a runtime call") \
273 \
274 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
275 "Make all non code cache addresses to be unreachable by " \
276 "forcing use of 64bit literal fixups") \
277 \
278 develop(bool, TraceDerivedPointers, false, \
279 "Trace traversal of derived pointers on stack") \
280 \
281 develop(bool, TraceCodeBlobStacks, false, \
282 "Trace stack-walk of codeblobs") \
283 \
284 develop(bool, PrintRewrites, false, \
285 "Print methods that are being rewritten") \
286 \
287 product(bool, UseInlineCaches, true, \
288 "Use Inline Caches for virtual calls ") \
289 \
290 product(size_t, InlineCacheBufferSize, 10*K, EXPERIMENTAL, \
291 "InlineCacheBuffer size") \
292 \
293 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
294 "Inline arraycopy native that is known to be part of " \
295 "base library DLL") \
296 \
297 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
298 "Inline Object::hashCode() native that is known to be part " \
299 "of base library DLL") \
300 \
301 product(bool, InlineNatives, true, DIAGNOSTIC, \
302 "Inline natives that are known to be part of base library DLL") \
303 \
304 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
305 "Inline SinD, CosD, etc.") \
306 \
307 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
308 "Inline Class.isInstance, etc") \
309 \
310 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
311 "Inline Thread.currentThread, etc") \
312 \
313 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
314 "Inline memory ops (native methods) from Unsafe") \
315 \
316 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
317 "Use intrinsics for AES versions of crypto") \
318 \
319 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
320 "Use intrinsics for the paralleled version of AES/CTR crypto") \
321 \
322 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
323 "Use intrinsics for the vectorized version of ChaCha20") \
324 \
325 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
326 "Use intrinsics for MD5 crypto hash function") \
327 \
328 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
329 "Use intrinsics for SHA-1 crypto hash function. " \
330 "Requires that UseSHA is enabled.") \
331 \
332 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
333 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
334 "Requires that UseSHA is enabled.") \
335 \
336 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
337 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
338 "Requires that UseSHA is enabled.") \
339 \
340 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
341 "Use intrinsics for SHA3 crypto hash function. " \
342 "Requires that UseSHA is enabled.") \
343 \
344 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
345 "use intrinsics for java.util.zip.CRC32") \
346 \
347 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
348 "use intrinsics for java.util.zip.CRC32C") \
349 \
350 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
351 "use intrinsics for java.util.zip.Adler32") \
352 \
353 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
354 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
355 \
356 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
357 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
358 \
359 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
360 "Enables intrinsification of Math.copySign") \
361 \
362 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
363 "Enables intrinsification of Math.signum") \
364 \
365 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
366 "Use Compiler thread for compiler's stubs generation") \
367 \
368 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
369 "do not expand intrinsics whose (internal) names appear here") \
370 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
371 \
372 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
373 "Control intrinsics using a list of +/- (internal) names, " \
374 "separated by commas") \
375 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
376 \
377 develop(bool, TraceCallFixup, false, \
378 "Trace all call fixups") \
379 \
380 develop(bool, DeoptimizeALot, false, \
381 "Deoptimize at every exit from the runtime system") \
382 \
383 develop(ccstrlist, DeoptimizeOnlyAt, "", \
384 "A comma separated list of bcis to deoptimize at") \
385 \
386 develop(bool, DeoptimizeRandom, false, \
387 "Deoptimize random frames on random exit from the runtime system")\
388 \
389 develop(bool, ZombieALot, false, \
390 "Create non-entrant nmethods at exit from the runtime system") \
391 \
392 develop(bool, WalkStackALot, false, \
393 "Trace stack (no print) at every exit from the runtime system") \
394 \
395 develop(bool, DeoptimizeObjectsALot, false, \
396 "For testing purposes concurrent threads revert optimizations " \
397 "based on escape analysis at intervals given with " \
398 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
399 "with DeoptimizeObjectsALotThreadCountSingle and " \
400 "DeoptimizeObjectsALotThreadCountAll.") \
401 \
402 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
403 "Interval for DeoptimizeObjectsALot.") \
404 range(0, max_jlong) \
405 \
406 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
407 "The number of threads that revert optimizations based on " \
408 "escape analysis for a single thread if DeoptimizeObjectsALot " \
409 "is enabled. The target thread is selected round robin." ) \
410 range(0, max_jint) \
411 \
412 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
413 "The number of threads that revert optimizations based on " \
414 "escape analysis for all threads if DeoptimizeObjectsALot " \
415 "is enabled." ) \
416 range(0, max_jint) \
417 \
418 develop(bool, VerifyLastFrame, false, \
419 "Verify oops on last frame on entry to VM") \
420 \
421 product(bool, SafepointTimeout, false, \
422 "Time out and warn or fail after SafepointTimeoutDelay " \
423 "milliseconds if failed to reach safepoint") \
424 \
425 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
426 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
427 \
428 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
429 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
430 range(0, max_jlong) \
431 \
432 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
433 "Abort upon failure to complete VM operation promptly") \
434 \
435 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
436 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
437 range(0, max_intx) \
438 \
439 product(bool, MaxFDLimit, true, \
440 "Bump the number of file descriptors to maximum (Unix only)") \
441 \
442 product(bool, LogEvents, true, DIAGNOSTIC, \
443 "Enable the various ring buffer event logs") \
444 \
445 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
446 "Number of ring buffer event logs") \
447 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
448 \
449 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
450 "Enable the Java bytecode verifier for remote classes") \
451 \
452 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
453 "Enable the Java bytecode verifier for local classes") \
454 \
455 develop(bool, VerifyStackAtCalls, false, \
456 "Verify that the stack pointer is unchanged after calls") \
457 \
458 develop(bool, TraceJavaAssertions, false, \
459 "Trace java language assertions") \
460 \
461 develop(bool, VerifyCodeCache, false, \
462 "Verify code cache on memory allocation/deallocation") \
463 \
464 develop(bool, ZapResourceArea, trueInDebug, \
465 "Zap freed resource/arena space") \
466 \
467 develop(bool, ZapVMHandleArea, trueInDebug, \
468 "Zap freed VM handle space") \
469 \
470 develop(bool, ZapStackSegments, trueInDebug, \
471 "Zap allocated/freed stack segments") \
472 \
473 develop(bool, ZapUnusedHeapArea, trueInDebug, \
474 "Zap unused heap space") \
475 \
476 develop(bool, CheckZapUnusedHeapArea, false, \
477 "Check zapping of unused heap space") \
478 \
479 develop(bool, ZapFillerObjects, trueInDebug, \
480 "Zap filler objects") \
481 \
482 develop(bool, ZapTLAB, trueInDebug, \
483 "Zap allocated TLABs") \
484 \
485 product(bool, ExecutingUnitTests, false, \
486 "Whether the JVM is running unit tests or not") \
487 \
488 develop(uint, ErrorHandlerTest, 0, \
489 "If > 0, provokes an error after VM initialization; the value " \
490 "determines which error to provoke. See controlled_crash() " \
491 "in vmError.cpp.") \
492 range(0, 17) \
493 \
494 develop(uint, TestCrashInErrorHandler, 0, \
495 "If > 0, provokes an error inside VM error handler (a secondary " \
496 "crash). see controlled_crash() in vmError.cpp") \
497 range(0, 17) \
498 \
499 develop(bool, TestSafeFetchInErrorHandler, false , \
500 "If true, tests SafeFetch inside error handler.") \
501 \
502 develop(bool, TestUnresponsiveErrorHandler, false, \
503 "If true, simulates an unresponsive error handler.") \
504 \
505 develop(bool, Verbose, false, \
506 "Print additional debugging information from other modes") \
507 \
508 develop(bool, PrintMiscellaneous, false, \
509 "Print uncategorized debugging information (requires +Verbose)") \
510 \
511 develop(bool, WizardMode, false, \
512 "Print much more debugging information") \
513 \
514 product(bool, ShowMessageBoxOnError, false, \
515 "Keep process alive on VM fatal error") \
516 \
517 product(bool, CreateCoredumpOnCrash, true, \
518 "Create core/mini dump on VM fatal error") \
519 \
520 product(uint64_t, ErrorLogTimeout, 2 * 60, \
521 "Timeout, in seconds, to limit the time spent on writing an " \
522 "error log in case of a crash.") \
523 range(0, (uint64_t)max_jlong/1000) \
524 \
525 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
526 "If enabled, show details on secondary crashes in the error log") \
527 \
528 develop(intx, TraceDwarfLevel, 0, \
529 "Debug levels for the dwarf parser") \
530 range(0, 4) \
531 \
532 product(bool, SuppressFatalErrorMessage, false, \
533 "Report NO fatal error message (avoid deadlock)") \
534 \
535 product(ccstrlist, OnError, "", \
536 "Run user-defined commands on fatal error; see VMError.cpp " \
537 "for examples") \
538 \
539 product(ccstrlist, OnOutOfMemoryError, "", \
540 "Run user-defined commands on first java.lang.OutOfMemoryError " \
541 "thrown from JVM") \
542 \
543 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
544 "Dump heap to file before any major stop-the-world GC " \
545 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
546 \
547 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
548 "Dump heap to file after any major stop-the-world GC " \
549 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
550 \
551 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
552 "Limit the number of heap dumps triggered by " \
553 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
554 "(0 means no limit)") \
555 \
556 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
557 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
558 "from JVM " \
559 "(also see HeapDumpPath, HeapDumpGzipLevel)") \
560 \
561 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
562 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
563 "or HeapDumpAfterFullGC is on, the path (filename or " \
564 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
565 "in the working directory)") \
566 \
567 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
568 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
569 "or HeapDumpAfterFullGC is on, the gzip compression " \
570 "level of the dump file. 0 (the default) disables gzip " \
571 "compression. Otherwise the level must be between 1 and 9.") \
572 range(0, 9) \
573 \
574 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
575 "Native memory tracking options") \
576 \
577 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
578 "Print native memory tracking summary data if it is on") \
579 \
580 product(bool, LogCompilation, false, DIAGNOSTIC, \
581 "Log compilation activity in detail to LogFile") \
582 \
583 product(bool, PrintCompilation, false, \
584 "Print compilations") \
585 \
586 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
587 "Repeat compilation without installing code (number of times)") \
588 range(0, max_jint) \
589 \
590 product(bool, PrintExtendedThreadInfo, false, \
591 "Print more information in thread dump") \
592 \
593 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
594 "0: do not allow scavengable oops in the code cache; " \
595 "1: allow scavenging from the code cache; " \
596 "2: emit as many constants as the compiler can see") \
597 range(0, 2) \
598 \
599 product(bool, AlwaysRestoreFPU, false, \
600 "Restore the FPU control word after every JNI call (expensive)") \
601 \
602 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
603 "Print additional statistics per compilation") \
604 \
605 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
606 "Print code generated for i2c/c2i adapters") \
607 \
608 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
609 "Verify that i2c/c2i adapters are called properly") \
610 \
611 develop(bool, VerifyAdapterSharing, false, \
612 "Verify that the code for shared adapters is the equivalent") \
613 \
614 product(bool, PrintAssembly, false, DIAGNOSTIC, \
615 "Print assembly code (using external disassembler.so)") \
616 \
617 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
618 "Print options string passed to disassembler.so") \
619 \
620 develop(bool, PrintNMethodStatistics, false, \
621 "Print a summary statistic for the generated nmethods") \
622 \
623 product(bool, PrintNMethods, false, DIAGNOSTIC, \
624 "Print assembly code for nmethods when generated") \
625 \
626 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
627 "Print assembly code for native nmethods when generated") \
628 \
629 develop(bool, PrintDebugInfo, false, \
630 "Print debug information for all nmethods when generated") \
631 \
632 develop(bool, PrintRelocations, false, \
633 "Print relocation information for all nmethods when generated") \
634 \
635 develop(bool, PrintDependencies, false, \
636 "Print dependency information for all nmethods when generated") \
637 \
638 develop(bool, PrintExceptionHandlers, false, \
639 "Print exception handler tables for all nmethods when generated") \
640 \
641 develop(bool, StressCompiledExceptionHandlers, false, \
642 "Exercise compiled exception handlers") \
643 \
644 develop(bool, InterceptOSException, false, \
645 "Start debugger when an implicit OS (e.g. null pointer) " \
646 "exception happens") \
647 \
648 product(bool, PrintCodeCache, false, \
649 "Print the code cache memory usage when exiting") \
650 \
651 develop(bool, PrintCodeCache2, false, \
652 "Print detailed usage information on the code cache when exiting")\
653 \
654 product(bool, PrintCodeCacheOnCompilation, false, \
655 "Print the code cache memory usage each time a method is " \
656 "compiled") \
657 \
658 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
659 "Print code heap usage statistics on exit and on full condition") \
660 \
661 product(bool, PrintStubCode, false, DIAGNOSTIC, \
662 "Print generated stub code") \
663 \
664 product(bool, StackTraceInThrowable, true, \
665 "Collect backtrace in throwable when exception happens") \
666 \
667 product(bool, OmitStackTraceInFastThrow, true, \
668 "Omit backtraces for some 'hot' exceptions in optimized code") \
669 \
670 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
671 "Show exception messages from RuntimeExceptions that contain " \
672 "snippets of the failing code. Disable this to improve privacy.") \
673 \
674 product(bool, PrintWarnings, true, \
675 "Print JVM warnings to output stream") \
676 \
677 develop(bool, RegisterReferences, true, \
678 "Tell whether the VM should register soft/weak/final/phantom " \
679 "references") \
680 \
681 develop(bool, PrintCodeCacheExtension, false, \
682 "Print extension of code cache") \
683 \
684 develop(bool, UsePrivilegedStack, true, \
685 "Enable the security JVM functions") \
686 \
687 product(bool, ClassUnloading, true, \
688 "Do unloading of classes") \
689 \
690 product(bool, ClassUnloadingWithConcurrentMark, true, \
691 "Do unloading of classes with a concurrent marking cycle") \
692 \
693 develop(bool, PrintSystemDictionaryAtExit, false, \
694 "Print the system dictionary at exit") \
695 \
696 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
697 "Print the class loader data graph at exit") \
698 \
699 product(bool, AllowParallelDefineClass, false, \
700 "Allow parallel defineClass requests for class loaders " \
701 "registering as parallel capable") \
702 \
703 product_pd(bool, DontYieldALot, \
704 "(Deprecated) Throw away obvious excess yield calls") \
705 \
706 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
707 "Disable the use of stack guard pages if the JVM is loaded " \
708 "on the primordial process thread") \
709 \
710 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
711 "Do JVMTI virtual thread mount/unmount transitions " \
712 "(disabling this flag implies no JVMTI events are posted)") \
713 \
714 /* notice: the max range value here is max_jint, not max_intx */ \
715 /* because of overflow issue */ \
716 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
717 "Async deflate idle monitors every so many milliseconds when " \
718 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
719 range(0, max_jint) \
720 \
721 /* notice: the max range value here is max_jint, not max_intx */ \
722 /* because of overflow issue */ \
723 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
724 "Async deflate idle monitors every so many milliseconds even " \
725 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
726 range(0, max_jint) \
727 \
728 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
729 "Used to estimate a variable ceiling based on number of threads " \
730 "for use with MonitorUsedDeflationThreshold (0 is off).") \
731 range(0, max_uintx) \
732 \
733 /* notice: the max range value here is max_jint, not max_intx */ \
734 /* because of overflow issue */ \
735 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
736 "The maximum number of monitors to deflate, unlink and delete " \
737 "at one time (minimum is 1024).") \
738 range(1024, max_jint) \
739 \
740 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
741 "The maximum number of monitors to unlink in one batch. ") \
742 range(1, max_jint) \
743 \
744 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
745 "Percentage of used monitors before triggering deflation (0 is " \
746 "off). The check is performed on AsyncDeflationInterval or " \
747 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
748 range(0, 100) \
749 \
750 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
751 "Max number of no progress async deflation attempts to tolerate " \
752 "before adjusting the in_use_list_ceiling up (0 is off).") \
753 range(0, max_uintx) \
754 \
755 product(intx, hashCode, 5, EXPERIMENTAL, \
756 "(Unstable) select hashCode generation algorithm") \
757 \
758 product(bool, ReduceSignalUsage, false, \
759 "Reduce the use of OS signals in Java and/or the VM") \
760 \
761 develop(bool, LoadLineNumberTables, true, \
762 "Tell whether the class file parser loads line number tables") \
763 \
764 develop(bool, LoadLocalVariableTables, true, \
765 "Tell whether the class file parser loads local variable tables") \
766 \
767 develop(bool, LoadLocalVariableTypeTables, true, \
768 "Tell whether the class file parser loads local variable type" \
769 "tables") \
770 \
771 product(bool, AllowUserSignalHandlers, false, \
772 "Application will install primary signal handlers for the JVM " \
773 "(Unix only)") \
774 \
775 product(bool, UseSignalChaining, true, \
776 "Use signal-chaining to invoke signal handlers installed " \
777 "by the application (Unix only)") \
778 \
779 product(bool, RestoreMXCSROnJNICalls, false, \
780 "Restore MXCSR when returning from JNI calls") \
781 \
782 product(bool, CheckJNICalls, false, \
783 "Verify all arguments to JNI calls") \
784 \
785 product(bool, UseFastJNIAccessors, true, \
786 "Use optimized versions of Get<Primitive>Field") \
787 \
788 product(intx, MaxJNILocalCapacity, 65536, \
789 "Maximum allowable local JNI handle capacity to " \
790 "EnsureLocalCapacity() and PushLocalFrame(), " \
791 "where <= 0 is unlimited, default: 65536") \
792 range(min_intx, max_intx) \
793 \
794 product(bool, EagerXrunInit, false, \
795 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
796 "but not all -Xrun libraries may support the state of the VM " \
797 "at this time") \
798 \
799 product(bool, PreserveAllAnnotations, false, \
800 "(Deprecated) Preserve RuntimeInvisibleAnnotations as well " \
801 "as RuntimeVisibleAnnotations") \
802 \
803 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
804 "Number of OutOfMemoryErrors preallocated with backtrace") \
805 \
806 product(bool, UseXMMForArrayCopy, false, \
807 "Use SSE2 MOVQ instruction for Arraycopy") \
808 \
809 develop(bool, PrintFieldLayout, false, \
810 "Print field layout for each class") \
811 \
812 /* Need to limit the extent of the padding to reasonable size. */\
813 /* 8K is well beyond the reasonable HW cache line size, even with */\
814 /* aggressive prefetching, while still leaving the room for segregating */\
815 /* among the distinct pages. */\
816 product(int, ContendedPaddingWidth, 128, \
817 "How many bytes to pad the fields/classes marked @Contended with")\
818 range(0, 8192) \
819 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
820 \
821 product(bool, EnableContended, true, \
822 "Enable @Contended annotation support") \
823 \
824 product(bool, RestrictContended, true, \
825 "Restrict @Contended to trusted classes") \
826 \
827 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
828 "Detect and take action upon identifying synchronization on " \
829 "value based classes. Modes: " \
830 "0: off; " \
831 "1: exit with fatal error; " \
832 "2: log message to stdout. Output file can be specified with " \
833 " -Xlog:valuebasedclasses. If JFR is running it will " \
834 " also generate JFR events.") \
835 range(0, 2) \
836 \
837 product(bool, ExitOnOutOfMemoryError, false, \
838 "JVM exits on the first occurrence of an out-of-memory error " \
839 "thrown from JVM") \
840 \
841 product(bool, CrashOnOutOfMemoryError, false, \
842 "JVM aborts, producing an error log and core/mini dump, on the " \
843 "first occurrence of an out-of-memory error thrown from JVM") \
844 \
845 product(intx, UserThreadWaitAttemptsAtExit, 30, \
846 "The number of times to wait for user threads to stop executing " \
847 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
848 "The maximum number of waits is 1000, to wait at most 10 " \
849 "seconds.") \
850 range(0, 1000) \
851 \
852 /* tracing */ \
853 \
854 develop(bool, StressRewriter, false, \
855 "Stress linktime bytecode rewriting") \
856 \
857 product(ccstr, TraceJVMTI, nullptr, \
858 "Trace flags for JVMTI functions and events") \
859 \
860 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
861 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
862 "This option can change an EMCP method into an obsolete method " \
863 "and can affect tests that expect specific methods to be EMCP. " \
864 "This option should be used with caution.") \
865 \
866 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
867 "(Deprecated) Allow redefinition to add and delete private " \
868 "static or final methods for compatibility with old releases") \
869 \
870 develop(bool, TraceBytecodes, false, \
871 "Trace bytecode execution") \
872 \
873 develop(bool, VerifyDependencies, trueInDebug, \
874 "Exercise and verify the compilation dependency mechanism") \
875 \
876 develop(bool, TraceNewOopMapGeneration, false, \
877 "Trace OopMapGeneration") \
878 \
879 develop(bool, TraceNewOopMapGenerationDetailed, false, \
880 "Trace OopMapGeneration: print detailed cell states") \
881 \
882 develop(bool, TimeOopMap, false, \
883 "Time calls to GenerateOopMap::compute_map() in sum") \
884 \
885 develop(bool, TimeOopMap2, false, \
886 "Time calls to GenerateOopMap::compute_map() individually") \
887 \
888 develop(bool, TraceOopMapRewrites, false, \
889 "Trace rewriting of methods during oop map generation") \
890 \
891 develop(bool, TraceFinalizerRegistration, false, \
892 "Trace registration of final references") \
893 \
894 product(bool, IgnoreEmptyClassPaths, false, \
895 "Ignore empty path elements in -classpath") \
896 \
897 product(bool, PrintHeapAtSIGBREAK, true, \
898 "Print heap layout in response to SIGBREAK") \
899 \
900 product(bool, PrintClassHistogram, false, MANAGEABLE, \
901 "Print a histogram of class instances") \
902 \
903 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
904 "The percentage of the used heap that the instances of a class " \
905 "must occupy for the class to generate a trace event") \
906 range(0.0, 100.0) \
907 \
908 /* JVMTI heap profiling */ \
909 \
910 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
911 "Verify memory system before JVMTI iteration") \
912 \
913 /* compiler */ \
914 \
915 /* notice: the max range value here is max_jint, not max_intx */ \
916 /* because of overflow issue */ \
917 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
918 "Number of compiler threads to run") \
919 range(0, max_jint) \
920 constraint(CICompilerCountConstraintFunc, AfterErgo) \
921 \
922 product(bool, UseDynamicNumberOfCompilerThreads, true, \
923 "Dynamically choose the number of parallel compiler threads") \
924 \
925 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
926 "Reduce the number of parallel compiler threads when they " \
927 "are not used") \
928 \
929 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
930 "Trace creation and removal of compiler threads") \
931 \
932 product(ccstr, LogClassLoadingCauseFor, nullptr, \
933 "Apply -Xlog:class+load+cause* to classes whose fully " \
934 "qualified name contains this string (\"*\" matches " \
935 "any class).") \
936 \
937 develop(bool, InjectCompilerCreationFailure, false, \
938 "Inject thread creation failures for " \
939 "UseDynamicNumberOfCompilerThreads") \
940 \
941 develop(bool, GenerateSynchronizationCode, true, \
942 "generate locking/unlocking code for synchronized methods and " \
943 "monitors") \
944 \
945 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
946 "Generate code for implicit null checks") \
947 \
948 product_pd(bool, TrapBasedNullChecks, \
949 "Generate code for null checks that uses a cmp and trap " \
950 "instruction raising SIGTRAP. This is only used if an access to" \
951 "null (+offset) will not raise a SIGSEGV, i.e.," \
952 "ImplicitNullChecks don't work (PPC64).") \
953 \
954 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
955 "Enable Thread SMR Statistics") \
956 \
957 product(bool, UseNotificationThread, true, \
958 "(Deprecated) Use Notification Thread") \
959 \
960 product(bool, Inline, true, \
961 "Enable inlining") \
962 \
963 product(bool, ClipInlining, true, \
964 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
965 \
966 develop(bool, UseCHA, true, \
967 "Enable CHA") \
968 \
969 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \
970 "Use vtable information during CHA") \
971 \
972 product(bool, UseTypeProfile, true, \
973 "Check interpreter profile for historically monomorphic calls") \
974 \
975 product(bool, PrintInlining, false, DIAGNOSTIC, \
976 "Print inlining optimizations") \
977 \
978 product(bool, UsePopCountInstruction, false, \
979 "Use population count instruction") \
980 \
981 develop(bool, TraceMethodReplacement, false, \
982 "Print when methods are replaced do to recompilation") \
983 \
984 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
985 "Minimum number of sweeper passes before an nmethod " \
986 "can be flushed") \
987 range(0, max_intx) \
988 \
989 develop(bool, StressCodeBuffers, false, \
990 "Exercise code buffer expansion and other rare state changes") \
991 \
992 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
993 "Generate extra debugging information for non-safepoints in " \
994 "nmethods") \
995 \
996 product(bool, PrintVMOptions, false, \
997 "Print flags that appeared on the command line") \
998 \
999 product(bool, IgnoreUnrecognizedVMOptions, false, \
1000 "Ignore unrecognized VM options") \
1001 \
1002 product(bool, PrintCommandLineFlags, false, \
1003 "Print flags specified on command line or set by ergonomics") \
1004 \
1005 product(bool, PrintFlagsInitial, false, \
1006 "Print all VM flags before argument processing and exit VM") \
1007 \
1008 product(bool, PrintFlagsFinal, false, \
1009 "Print all VM flags after argument and ergonomic processing") \
1010 \
1011 develop(bool, PrintFlagsWithComments, false, \
1012 "Print all VM flags with default values and descriptions and " \
1013 "exit") \
1014 \
1015 product(bool, PrintFlagsRanges, false, \
1016 "Print VM flags and their ranges") \
1017 \
1018 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1019 "Use a mutex to serialize output to tty and LogFile") \
1020 \
1021 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1022 "Display all VM output on the tty, independently of LogVMOutput") \
1023 \
1024 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1025 "Save VM output to LogFile") \
1026 \
1027 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1028 "If LogVMOutput or LogCompilation is on, save VM output to " \
1029 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1030 \
1031 product(ccstr, ErrorFile, nullptr, \
1032 "If an error occurs, save the error data to this file " \
1033 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1034 \
1035 product(bool, ExtensiveErrorReports, \
1036 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1037 "Error reports are more extensive.") \
1038 \
1039 product(bool, DisplayVMOutputToStderr, false, \
1040 "If DisplayVMOutput is true, display all VM output to stderr") \
1041 \
1042 product(bool, DisplayVMOutputToStdout, false, \
1043 "If DisplayVMOutput is true, display all VM output to stdout") \
1044 \
1045 product(bool, ErrorFileToStderr, false, \
1046 "If true, error data is printed to stderr instead of a file") \
1047 \
1048 product(bool, ErrorFileToStdout, false, \
1049 "If true, error data is printed to stdout instead of a file") \
1050 \
1051 develop(bool, VerifyHeavyMonitors, false, \
1052 "Checks that no stack locking happens when using " \
1053 "-XX:LockingMode=0 (LM_MONITOR)") \
1054 \
1055 product(bool, PrintStringTableStatistics, false, \
1056 "print statistics about the StringTable and SymbolTable") \
1057 \
1058 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1059 "verify StringTable contents at exit") \
1060 \
1061 develop(bool, PrintSymbolTableSizeHistogram, false, \
1062 "print histogram of the symbol table") \
1063 \
1064 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1065 "Call fatal if this exception is thrown. Example: " \
1066 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1067 \
1068 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1069 "Call fatal if the exception pointed by AbortVMOnException " \
1070 "has this message") \
1071 \
1072 develop(bool, DebugVtables, false, \
1073 "add debugging code to vtable dispatch") \
1074 \
1075 product(bool, RangeCheckElimination, true, \
1076 "Eliminate range checks") \
1077 \
1078 develop_pd(bool, UncommonNullCast, \
1079 "track occurrences of null in casts; adjust compiler tactics") \
1080 \
1081 develop(bool, TypeProfileCasts, true, \
1082 "treat casts like calls for purposes of type profiling") \
1083 \
1084 develop(bool, TraceLivenessGen, false, \
1085 "Trace the generation of liveness analysis information") \
1086 \
1087 develop(bool, TraceLivenessQuery, false, \
1088 "Trace queries of liveness analysis information") \
1089 \
1090 develop(bool, CollectIndexSetStatistics, false, \
1091 "Collect information about IndexSets") \
1092 \
1093 develop(int, FastAllocateSizeLimit, 128*K, \
1094 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1095 "Inline allocations larger than this in doublewords must go slow")\
1096 \
1097 product_pd(bool, CompactStrings, \
1098 "Enable Strings to use single byte chars in backing store") \
1099 \
1100 product_pd(uint, TypeProfileLevel, \
1101 "=XYZ, with Z: Type profiling of arguments at call; " \
1102 "Y: Type profiling of return value at call; " \
1103 "X: Type profiling of parameters to methods; " \
1104 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1105 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1106 \
1107 product(int, TypeProfileArgsLimit, 2, \
1108 "max number of call arguments to consider for type profiling") \
1109 range(0, 16) \
1110 \
1111 product(int, TypeProfileParmsLimit, 2, \
1112 "max number of incoming parameters to consider for type profiling"\
1113 ", -1 for all") \
1114 range(-1, 64) \
1115 \
1116 /* statistics */ \
1117 develop(bool, CountCompiledCalls, false, \
1118 "Count method invocations") \
1119 \
1120 develop(bool, ICMissHistogram, false, \
1121 "Produce histogram of IC misses") \
1122 \
1123 /* interpreter */ \
1124 product_pd(bool, RewriteBytecodes, \
1125 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1126 \
1127 product_pd(bool, RewriteFrequentPairs, \
1128 "Rewrite frequently used bytecode pairs into a single bytecode") \
1129 \
1130 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1131 "Print the generated interpreter code") \
1132 \
1133 product(bool, UseInterpreter, true, \
1134 "Use interpreter for non-compiled methods") \
1135 \
1136 develop(bool, UseFastSignatureHandlers, true, \
1137 "Use fast signature handlers for native calls") \
1138 \
1139 product(bool, UseLoopCounter, true, \
1140 "Increment invocation counter on backward branch") \
1141 \
1142 product_pd(bool, UseOnStackReplacement, \
1143 "Use on stack replacement, calls runtime if invoc. counter " \
1144 "overflows in loop") \
1145 \
1146 develop(bool, TraceOnStackReplacement, false, \
1147 "Trace on stack replacement") \
1148 \
1149 product_pd(bool, PreferInterpreterNativeStubs, \
1150 "Use always interpreter stubs for native methods invoked via " \
1151 "interpreter") \
1152 \
1153 develop(bool, CountBytecodes, false, \
1154 "Count number of bytecodes executed") \
1155 \
1156 develop(bool, PrintBytecodeHistogram, false, \
1157 "Print histogram of the executed bytecodes") \
1158 \
1159 develop(bool, PrintBytecodePairHistogram, false, \
1160 "Print histogram of the executed bytecode pairs") \
1161 \
1162 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1163 "Print code generated for native method signature handlers") \
1164 \
1165 develop(bool, VerifyOops, false, \
1166 "Do plausibility checks for oops") \
1167 \
1168 develop(bool, CheckUnhandledOops, false, \
1169 "Check for unhandled oops in VM code") \
1170 \
1171 develop(bool, VerifyJNIFields, trueInDebug, \
1172 "Verify jfieldIDs for instance fields") \
1173 \
1174 develop(bool, VerifyFPU, false, \
1175 "Verify FPU state (check for NaN's, etc.)") \
1176 \
1177 develop(bool, VerifyActivationFrameSize, false, \
1178 "Verify that activation frame didn't become smaller than its " \
1179 "minimal size") \
1180 \
1181 develop(bool, TraceFrequencyInlining, false, \
1182 "Trace frequency based inlining") \
1183 \
1184 develop_pd(bool, InlineIntrinsics, \
1185 "Use intrinsics in Interpreter that can be statically resolved") \
1186 \
1187 product_pd(bool, ProfileInterpreter, \
1188 "Profile at the bytecode level during interpretation") \
1189 \
1190 develop_pd(bool, ProfileTraps, \
1191 "Profile deoptimization traps at the bytecode level") \
1192 \
1193 product(intx, ProfileMaturityPercentage, 20, \
1194 "number of method invocations/branches (expressed as % of " \
1195 "CompileThreshold) before using the method's profile") \
1196 range(0, 100) \
1197 \
1198 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1199 "Print the results of +ProfileInterpreter at end of run") \
1200 \
1201 develop(bool, VerifyDataPointer, trueInDebug, \
1202 "Verify the method data pointer during interpreter profiling") \
1203 \
1204 develop(bool, CrashGCForDumpingJavaThread, false, \
1205 "Manually make GC thread crash then dump java stack trace; " \
1206 "Test only") \
1207 \
1208 /* compilation */ \
1209 product(bool, UseCompiler, true, \
1210 "Use Just-In-Time compilation") \
1211 \
1212 develop(intx, CounterHalfLifeTime, 30, \
1213 "Half-life time of invocation counters (in seconds)") \
1214 \
1215 product(bool, AlwaysCompileLoopMethods, false, \
1216 "When using recompilation, never interpret methods " \
1217 "containing loops") \
1218 \
1219 product(int, AllocatePrefetchStyle, 1, \
1220 "0 = no prefetch, " \
1221 "1 = generate prefetch instructions for each allocation, " \
1222 "2 = use TLAB watermark to gate allocation prefetch, " \
1223 "3 = generate one prefetch instruction per cache line") \
1224 range(0, 3) \
1225 \
1226 product(int, AllocatePrefetchDistance, -1, \
1227 "Distance to prefetch ahead of allocation pointer. " \
1228 "-1: use system-specific value (automatically determined") \
1229 range(-1, 512) \
1230 \
1231 product(int, AllocatePrefetchLines, 3, \
1232 "Number of lines to prefetch ahead of array allocation pointer") \
1233 range(1, 64) \
1234 \
1235 product(int, AllocateInstancePrefetchLines, 1, \
1236 "Number of lines to prefetch ahead of instance allocation " \
1237 "pointer") \
1238 range(1, 64) \
1239 \
1240 product(int, AllocatePrefetchStepSize, 16, \
1241 "Step size in bytes of sequential prefetch instructions") \
1242 range(1, 512) \
1243 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1244 \
1245 product(intx, AllocatePrefetchInstr, 0, \
1246 "Select instruction to prefetch ahead of allocation pointer") \
1247 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1248 \
1249 /* deoptimization */ \
1250 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1251 "Trace deoptimization") \
1252 \
1253 develop(bool, PrintDeoptimizationDetails, false, \
1254 "Print more information about deoptimization") \
1255 \
1256 develop(bool, DebugDeoptimization, false, \
1257 "Tracing various information while debugging deoptimization") \
1258 \
1259 product(double, SelfDestructTimer, 0.0, \
1260 "Will cause VM to terminate after a given time " \
1261 "(in fractional minutes) " \
1262 "(0.0 means off)") \
1263 range(0.0, (double)max_intx) \
1264 \
1265 product(int, MaxJavaStackTraceDepth, 1024, \
1266 "The maximum number of lines in the stack trace for Java " \
1267 "exceptions (0 means all)") \
1268 range(0, max_jint/2) \
1269 \
1270 /* notice: the max range value here is max_jint, not max_intx */ \
1271 /* because of overflow issue */ \
1272 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1273 "Guarantee a safepoint (at least) every so many milliseconds " \
1274 "(0 means none)") \
1275 range(0, max_jint) \
1276 \
1277 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1278 "Wake the ServiceThread to do periodic cleanup checks every so " \
1279 "many milliseconds (0 means none)") \
1280 range(0, max_jint) \
1281 \
1282 product(double, SafepointTimeoutDelay, 10000, \
1283 "Delay in milliseconds for option SafepointTimeout; " \
1284 "supports sub-millisecond resolution with fractional values.") \
1285 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1286 \
1287 product(bool, UseSystemMemoryBarrier, false, \
1288 "Try to enable system memory barrier if supported by OS") \
1289 \
1290 product(intx, NmethodSweepActivity, 4, \
1291 "Removes cold nmethods from code cache if > 0. Higher values " \
1292 "result in more aggressive sweeping") \
1293 range(0, 2000) \
1294 \
1295 develop(intx, MallocCatchPtr, -1, \
1296 "Hit breakpoint when mallocing/freeing this pointer") \
1297 \
1298 develop(int, StackPrintLimit, 100, \
1299 "number of stack frames to print in VM-level stack dump") \
1300 \
1301 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1302 "max number of compiled code units to print in error log") \
1303 range(0, VMError::max_error_log_print_code) \
1304 \
1305 develop(int, MaxElementPrintSize, 256, \
1306 "maximum number of elements to print") \
1307 \
1308 develop(intx, MaxSubklassPrintSize, 4, \
1309 "maximum number of subklasses to print when printing klass") \
1310 \
1311 develop(intx, MaxForceInlineLevel, 100, \
1312 "maximum number of nested calls that are forced for inlining " \
1313 "(using CompileCommand or marked w/ @ForceInline)") \
1314 range(0, max_jint) \
1315 \
1316 develop(intx, MethodHistogramCutoff, 100, \
1317 "The cutoff value for method invocation histogram (+CountCalls)") \
1318 \
1319 develop(intx, DeoptimizeALotInterval, 5, \
1320 "Number of exits until DeoptimizeALot kicks in") \
1321 \
1322 develop(intx, ZombieALotInterval, 5, \
1323 "Number of exits until ZombieALot kicks in") \
1324 \
1325 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1326 "Limit malloc allocation size from VM. Reaching a limit will " \
1327 "trigger an action (see flag). This feature requires " \
1328 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1329 "Usage:" \
1330 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1331 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1332 "sets one or more category-specific limits." \
1333 "<flag> defines the action upon reaching the limit:" \
1334 "\"fatal\": end VM with a fatal error at the allocation site" \
1335 "\"oom\" : will mimic a native OOM" \
1336 "If <flag> is omitted, \"fatal\" is the default." \
1337 "Examples:\n" \
1338 "-XX:MallocLimit=2g" \
1339 "-XX:MallocLimit=2g:oom" \
1340 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1341 \
1342 product(intx, TypeProfileWidth, 2, \
1343 "Number of receiver types to record in call/cast profile") \
1344 range(0, 8) \
1345 \
1346 develop(intx, BciProfileWidth, 2, \
1347 "Number of return bci's to record in ret profile") \
1348 \
1349 product(intx, PerMethodRecompilationCutoff, 400, \
1350 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1351 range(-1, max_intx) \
1352 \
1353 product(intx, PerBytecodeRecompilationCutoff, 200, \
1354 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1355 range(-1, max_intx) \
1356 \
1357 product(intx, PerMethodTrapLimit, 100, \
1358 "Limit on traps (of one kind) in a method (includes inlines)") \
1359 range(0, max_jint) \
1360 \
1361 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1362 "Limit on speculative traps (of one kind) in a method " \
1363 "(includes inlines)") \
1364 range(0, max_jint) \
1365 \
1366 product(intx, PerBytecodeTrapLimit, 4, \
1367 "Limit on traps (of one kind) at a particular BCI") \
1368 range(0, max_jint) \
1369 \
1370 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1371 "Extra method data trap entries for speculation") \
1372 \
1373 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1374 "Ratio of call site execution to caller method invocation") \
1375 \
1376 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1377 "Minimum ratio of call site execution to caller method" \
1378 "invocation to be considered for inlining") \
1379 \
1380 develop(intx, InlineThrowCount, 50, \
1381 "Force inlining of interpreted methods that throw this often") \
1382 range(0, max_jint) \
1383 \
1384 develop(intx, InlineThrowMaxSize, 200, \
1385 "Force inlining of throwing methods smaller than this") \
1386 range(0, max_jint) \
1387 \
1388 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1389 "Initial threshold (in bytes) at which a garbage collection " \
1390 "is done to reduce Metaspace usage") \
1391 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1392 \
1393 product(size_t, MaxMetaspaceSize, max_uintx, \
1394 "Maximum size of Metaspaces (in bytes)") \
1395 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1396 \
1397 product(size_t, CompressedClassSpaceSize, 1*G, \
1398 "Maximum size of class area in Metaspace when compressed " \
1399 "class pointers are used") \
1400 range(1*M, 3*G) \
1401 \
1402 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1403 "Force the class space to be allocated at this address or " \
1404 "fails VM initialization (requires -Xshare=off.") \
1405 \
1406 develop(bool, RandomizeClassSpaceLocation, true, \
1407 "Randomize location of class space.") \
1408 \
1409 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1410 "Print metaspace statistics upon VM exit.") \
1411 \
1412 develop(bool, MetaspaceGuardAllocations, false, \
1413 "Metapace allocations are guarded.") \
1414 \
1415 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1416 "The minimum percentage of heap free after GC to avoid expansion."\
1417 " For most GCs this applies to the old generation. In G1 and" \
1418 " ParallelGC it applies to the whole heap.") \
1419 range(0, 100) \
1420 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1421 \
1422 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1423 "The maximum percentage of heap free after GC to avoid shrinking."\
1424 " For most GCs this applies to the old generation. In G1 and" \
1425 " ParallelGC it applies to the whole heap.") \
1426 range(0, 100) \
1427 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1428 \
1429 product(bool, ShrinkHeapInSteps, true, \
1430 "When disabled, informs the GC to shrink the java heap directly" \
1431 " to the target size at the next full GC rather than requiring" \
1432 " smaller steps during multiple full GCs.") \
1433 \
1434 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1435 "Number of milliseconds per MB of free space in the heap") \
1436 range(0, max_intx) \
1437 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1438 \
1439 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1440 "The minimum change in heap space due to GC (in bytes)") \
1441 range(0, max_uintx) \
1442 \
1443 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1444 "The minimum expansion of Metaspace (in bytes)") \
1445 range(0, max_uintx) \
1446 \
1447 product(uint, MaxMetaspaceFreeRatio, 70, \
1448 "The maximum percentage of Metaspace free after GC to avoid " \
1449 "shrinking") \
1450 range(0, 100) \
1451 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1452 \
1453 product(uint, MinMetaspaceFreeRatio, 40, \
1454 "The minimum percentage of Metaspace free after GC to avoid " \
1455 "expansion") \
1456 range(0, 99) \
1457 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1458 \
1459 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1460 "The maximum expansion of Metaspace without full GC (in bytes)") \
1461 range(0, max_uintx) \
1462 \
1463 /* stack parameters */ \
1464 product_pd(intx, StackYellowPages, \
1465 "Number of yellow zone (recoverable overflows) pages of size " \
1466 "4KB. If pages are bigger yellow zone is aligned up.") \
1467 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1468 \
1469 product_pd(intx, StackRedPages, \
1470 "Number of red zone (unrecoverable overflows) pages of size " \
1471 "4KB. If pages are bigger red zone is aligned up.") \
1472 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1473 \
1474 product_pd(intx, StackReservedPages, \
1475 "Number of reserved zone (reserved to annotated methods) pages" \
1476 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1477 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1478 \
1479 product(bool, RestrictReservedStack, true, \
1480 "Restrict @ReservedStackAccess to trusted classes") \
1481 \
1482 /* greater stack shadow pages can't generate instruction to bang stack */ \
1483 product_pd(intx, StackShadowPages, \
1484 "Number of shadow zone (for overflow checking) pages of size " \
1485 "4KB. If pages are bigger shadow zone is aligned up. " \
1486 "This should exceed the depth of the VM and native call stack.") \
1487 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1488 \
1489 product_pd(intx, ThreadStackSize, \
1490 "Thread Stack Size (in Kbytes)") \
1491 range(0, 1 * M) \
1492 \
1493 product_pd(intx, VMThreadStackSize, \
1494 "Non-Java Thread Stack Size (in Kbytes)") \
1495 range(0, max_intx/(1 * K)) \
1496 \
1497 product_pd(intx, CompilerThreadStackSize, \
1498 "Compiler Thread Stack Size (in Kbytes)") \
1499 range(0, max_intx/(1 * K)) \
1500 \
1501 develop_pd(size_t, JVMInvokeMethodSlack, \
1502 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1503 \
1504 /* code cache parameters */ \
1505 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1506 "Code cache segment size (in bytes) - smallest unit of " \
1507 "allocation") \
1508 range(1, 1024) \
1509 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1510 \
1511 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1512 "Code entry alignment for generated code (in bytes)") \
1513 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1514 \
1515 product_pd(intx, OptoLoopAlignment, \
1516 "Align inner loops to zero relative to this modulus") \
1517 range(1, 128) \
1518 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1519 \
1520 product_pd(uintx, InitialCodeCacheSize, \
1521 "Initial code cache size (in bytes)") \
1522 constraint(VMPageSizeConstraintFunc, AtParse) \
1523 \
1524 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1525 "Minimum code cache size (in bytes) required to start VM.") \
1526 range(0, max_uintx) \
1527 \
1528 product(bool, SegmentedCodeCache, false, \
1529 "Use a segmented code cache") \
1530 \
1531 product_pd(uintx, ReservedCodeCacheSize, \
1532 "Reserved code cache size (in bytes) - maximum code cache size") \
1533 constraint(VMPageSizeConstraintFunc, AtParse) \
1534 \
1535 product_pd(uintx, NonProfiledCodeHeapSize, \
1536 "Size of code heap with non-profiled methods (in bytes)") \
1537 range(0, max_uintx) \
1538 \
1539 product_pd(uintx, ProfiledCodeHeapSize, \
1540 "Size of code heap with profiled methods (in bytes)") \
1541 range(0, max_uintx) \
1542 \
1543 product_pd(uintx, NonNMethodCodeHeapSize, \
1544 "Size of code heap with non-nmethods (in bytes)") \
1545 constraint(VMPageSizeConstraintFunc, AtParse) \
1546 \
1547 product_pd(uintx, CodeCacheExpansionSize, \
1548 "Code cache expansion size (in bytes)") \
1549 range(32*K, max_uintx) \
1550 \
1551 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1552 "Minimum number of segments in a code cache block") \
1553 range(1, 100) \
1554 \
1555 develop(bool, ExitOnFullCodeCache, false, \
1556 "Exit the VM if we fill the code cache") \
1557 \
1558 product(bool, UseCodeCacheFlushing, true, \
1559 "Remove cold/old nmethods from the code cache") \
1560 \
1561 product(double, SweeperThreshold, 15.0, \
1562 "Threshold when a code cache unloading GC is invoked." \
1563 "Value is percentage of ReservedCodeCacheSize.") \
1564 range(0.0, 100.0) \
1565 \
1566 product(uintx, StartAggressiveSweepingAt, 10, \
1567 "Start aggressive sweeping if X[%] of the code cache is free." \
1568 "Segmented code cache: X[%] of the non-profiled heap." \
1569 "Non-segmented code cache: X[%] of the total code cache") \
1570 range(0, 100) \
1571 \
1572 /* interpreter debugging */ \
1573 develop(intx, BinarySwitchThreshold, 5, \
1574 "Minimal number of lookupswitch entries for rewriting to binary " \
1575 "switch") \
1576 \
1577 develop(intx, StopInterpreterAt, 0, \
1578 "Stop interpreter execution at specified bytecode number") \
1579 \
1580 develop(intx, TraceBytecodesAt, 0, \
1581 "Trace bytecodes starting with specified bytecode number") \
1582 \
1583 develop(intx, TraceBytecodesStopAt, 0, \
1584 "Stop bytecode tracing at the specified bytecode number") \
1585 \
1586 /* Priorities */ \
1587 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1588 \
1589 product(int, ThreadPriorityPolicy, 0, \
1590 "0 : Normal. "\
1591 " VM chooses priorities that are appropriate for normal "\
1592 " applications. "\
1593 " On Windows applications are allowed to use higher native "\
1594 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1595 " not use the highest possible native priority, "\
1596 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1597 " system threads. On Linux thread priorities are ignored "\
1598 " because the OS does not support static priority in "\
1599 " SCHED_OTHER scheduling class which is the only choice for "\
1600 " non-root, non-realtime applications. "\
1601 "1 : Aggressive. "\
1602 " Java thread priorities map over to the entire range of "\
1603 " native thread priorities. Higher Java thread priorities map "\
1604 " to higher native thread priorities. This policy should be "\
1605 " used with care, as sometimes it can cause performance "\
1606 " degradation in the application and/or the entire system. On "\
1607 " Linux/BSD/macOS this policy requires root privilege or an "\
1608 " extended capability.") \
1609 range(0, 1) \
1610 \
1611 product(bool, ThreadPriorityVerbose, false, \
1612 "Print priority changes") \
1613 \
1614 product(int, CompilerThreadPriority, -1, \
1615 "The native priority at which compiler threads should run " \
1616 "(-1 means no change)") \
1617 range(min_jint, max_jint) \
1618 \
1619 product(int, VMThreadPriority, -1, \
1620 "The native priority at which the VM thread should run " \
1621 "(-1 means no change)") \
1622 range(-1, 127) \
1623 \
1624 product(int, JavaPriority1_To_OSPriority, -1, \
1625 "Map Java priorities to OS priorities") \
1626 range(-1, 127) \
1627 \
1628 product(int, JavaPriority2_To_OSPriority, -1, \
1629 "Map Java priorities to OS priorities") \
1630 range(-1, 127) \
1631 \
1632 product(int, JavaPriority3_To_OSPriority, -1, \
1633 "Map Java priorities to OS priorities") \
1634 range(-1, 127) \
1635 \
1636 product(int, JavaPriority4_To_OSPriority, -1, \
1637 "Map Java priorities to OS priorities") \
1638 range(-1, 127) \
1639 \
1640 product(int, JavaPriority5_To_OSPriority, -1, \
1641 "Map Java priorities to OS priorities") \
1642 range(-1, 127) \
1643 \
1644 product(int, JavaPriority6_To_OSPriority, -1, \
1645 "Map Java priorities to OS priorities") \
1646 range(-1, 127) \
1647 \
1648 product(int, JavaPriority7_To_OSPriority, -1, \
1649 "Map Java priorities to OS priorities") \
1650 range(-1, 127) \
1651 \
1652 product(int, JavaPriority8_To_OSPriority, -1, \
1653 "Map Java priorities to OS priorities") \
1654 range(-1, 127) \
1655 \
1656 product(int, JavaPriority9_To_OSPriority, -1, \
1657 "Map Java priorities to OS priorities") \
1658 range(-1, 127) \
1659 \
1660 product(int, JavaPriority10_To_OSPriority,-1, \
1661 "Map Java priorities to OS priorities") \
1662 range(-1, 127) \
1663 \
1664 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1665 "Java thread priority 10 maps to critical scheduling priority") \
1666 \
1667 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1668 "Compiler thread(s) run at critical scheduling priority") \
1669 \
1670 develop(intx, NewCodeParameter, 0, \
1671 "Testing Only: Create a dedicated integer parameter before " \
1672 "putback") \
1673 \
1674 /* new oopmap storage allocation */ \
1675 develop(intx, MinOopMapAllocation, 8, \
1676 "Minimum number of OopMap entries in an OopMapSet") \
1677 \
1678 /* recompilation */ \
1679 product_pd(intx, CompileThreshold, \
1680 "number of interpreted method invocations before (re-)compiling") \
1681 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1682 \
1683 product_pd(bool, TieredCompilation, \
1684 "Enable tiered compilation") \
1685 \
1686 /* Properties for Java libraries */ \
1687 \
1688 product(uint64_t, MaxDirectMemorySize, 0, \
1689 "Maximum total size of NIO direct-buffer allocations. " \
1690 "Ignored if not explicitly set.") \
1691 range(0, max_jlong) \
1692 \
1693 /* Flags used for temporary code during development */ \
1694 \
1695 product(bool, UseNewCode, false, DIAGNOSTIC, \
1696 "Testing Only: Use the new version while testing") \
1697 \
1698 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1699 "Testing Only: Use the new version while testing") \
1700 \
1701 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1702 "Testing Only: Use the new version while testing") \
1703 \
1704 develop(bool, UseDebuggerErgo, false, \
1705 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1706 "Turns on the other UseDebuggerErgo* flags") \
1707 \
1708 develop(bool, UseDebuggerErgo1, false, \
1709 "Debugging Only: Enable workarounds for debugger induced " \
1710 "os::processor_id() >= os::processor_count() problems") \
1711 \
1712 develop(bool, UseDebuggerErgo2, false, \
1713 "Debugging Only: Limit the number of spawned JVM threads") \
1714 \
1715 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1716 "Enable JVMTI asserts related to stack depth checks") \
1717 \
1718 /* flags for performance data collection */ \
1719 \
1720 product(bool, UsePerfData, true, \
1721 "Flag to disable jvmstat instrumentation for performance testing "\
1722 "and problem isolation purposes") \
1723 \
1724 product(bool, PerfDataSaveToFile, false, \
1725 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1726 \
1727 product(ccstr, PerfDataSaveFile, nullptr, \
1728 "Save PerfData memory to the specified absolute pathname. " \
1729 "The string %p in the file name (if present) " \
1730 "will be replaced by pid") \
1731 \
1732 product(int, PerfDataSamplingInterval, 50, \
1733 "Data sampling interval (in milliseconds)") \
1734 range(PeriodicTask::min_interval, max_jint) \
1735 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1736 \
1737 product(bool, PerfDisableSharedMem, false, \
1738 "Store performance data in standard memory") \
1739 \
1740 product(int, PerfDataMemorySize, 32*K, \
1741 "Size of performance data memory region. Will be rounded " \
1742 "up to a multiple of the native os page size.") \
1743 range(128, 32*64*K) \
1744 \
1745 product(int, PerfMaxStringConstLength, 1024, \
1746 "Maximum PerfStringConstant string length before truncation") \
1747 range(32, 32*K) \
1748 \
1749 product(bool, PerfAllowAtExitRegistration, false, \
1750 "Allow registration of atexit() methods") \
1751 \
1752 product(bool, PerfBypassFileSystemCheck, false, \
1753 "Bypass Win32 file system criteria checks (Windows Only)") \
1754 \
1755 product(int, UnguardOnExecutionViolation, 0, \
1756 "Unguard page and retry on no-execute fault (Win32 only) " \
1757 "0=off, 1=conservative, 2=aggressive") \
1758 range(0, 2) \
1759 \
1760 /* Serviceability Support */ \
1761 \
1762 product(bool, ManagementServer, false, \
1763 "Create JMX Management Server") \
1764 \
1765 product(bool, DisableAttachMechanism, false, \
1766 "Disable mechanism that allows tools to attach to this VM") \
1767 \
1768 product(bool, StartAttachListener, false, \
1769 "Always start Attach Listener at VM startup") \
1770 \
1771 product(bool, EnableDynamicAgentLoading, true, \
1772 "Allow tools to load agents with the attach mechanism") \
1773 \
1774 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1775 "Print java.util.concurrent locks in thread dump") \
1776 \
1777 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1778 "Print generated stub code for method handles") \
1779 \
1780 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1781 "perform extra checks when constructing method handles") \
1782 \
1783 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1784 "show method handle implementation frames (usually hidden)") \
1785 \
1786 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1787 "show virtual threads' carrier frames in exceptions") \
1788 \
1789 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1790 "trust final non-static declarations for constant folding") \
1791 \
1792 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1793 "Optimize loads from stable fields (marked w/ @Stable)") \
1794 \
1795 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1796 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1797 "resolved before the bootstrap method is called; 1: when a BSM " \
1798 "that may accept a BootstrapCallInfo is detected, use that API " \
1799 "to pass BSM arguments, which allows the BSM to delay their " \
1800 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1801 "via that API, instead of with the eagerly-resolved array.") \
1802 \
1803 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1804 "Causes the VM to pause at startup time and wait for the pause " \
1805 "file to be removed (default: ./vm.paused.<pid>)") \
1806 \
1807 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1808 "The file to create and for whose removal to await when pausing " \
1809 "at startup. (default: ./vm.paused.<pid>)") \
1810 \
1811 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1812 "Pause and wait for keypress on exit if a debugger is attached") \
1813 \
1814 product(bool, DTraceMethodProbes, false, \
1815 "Enable dtrace tool probes for method-entry and method-exit") \
1816 \
1817 product(bool, DTraceAllocProbes, false, \
1818 "Enable dtrace tool probes for object allocation") \
1819 \
1820 product(bool, DTraceMonitorProbes, false, \
1821 "Enable dtrace tool probes for monitor events") \
1822 \
1823 product(bool, RelaxAccessControlCheck, false, \
1824 "Relax the access control checks in the verifier") \
1825 \
1826 product(uintx, StringTableSize, defaultStringTableSize, \
1827 "Number of buckets in the interned String table " \
1828 "(will be rounded to nearest higher power of 2)") \
1829 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1830 \
1831 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1832 "Number of buckets in the JVM internal Symbol table") \
1833 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1834 \
1835 product(bool, UseStringDeduplication, false, \
1836 "Use string deduplication") \
1837 \
1838 product(uint, StringDeduplicationAgeThreshold, 3, \
1839 "A string must reach this age (or be promoted to an old region) " \
1840 "to be considered for deduplication") \
1841 range(1, markWord::max_age) \
1842 \
1843 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1844 "Approximate initial number of buckets in the table") \
1845 range(1, 1 * G) \
1846 \
1847 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1848 "Entries per bucket above which the table should be expanded") \
1849 range(0.1, 1000.0) \
1850 \
1851 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1852 "Entries per bucket below which the table should be shrunk") \
1853 range(0.01, 100.0) \
1854 \
1855 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1856 "Desired entries per bucket when resizing the table") \
1857 range(0.01, 1000.0) \
1858 \
1859 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1860 "Minimum number of dead table entries for cleaning the table") \
1861 \
1862 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1863 "Minimum percentage of dead table entries for cleaning the table") \
1864 range(1, 100) \
1865 \
1866 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1867 "Force more frequent table resizing") \
1868 \
1869 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1870 "Seed for the table hashing function; 0 requests computed seed") \
1871 \
1872 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1873 "Enable internal testing APIs") \
1874 \
1875 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1876 "Accesses to all variables should always be atomic") \
1877 \
1878 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1879 "Use unaligned memory accesses in Unsafe") \
1880 \
1881 product_pd(bool, PreserveFramePointer, \
1882 "Use the FP register for holding the frame pointer " \
1883 "and not as a general purpose register.") \
1884 \
1885 product(size_t, AsyncLogBufferSize, 2*M, \
1886 "Memory budget (in bytes) for the buffer of Asynchronous " \
1887 "Logging (-Xlog:async).") \
1888 range(100*K, 50*M) \
1889 \
1890 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1891 "When a class C is loaded, check that " \
1892 "(1) all intrinsics defined by the VM for class C are present "\
1893 "in the loaded class file and are marked with the " \
1894 "@IntrinsicCandidate annotation, that " \
1895 "(2) there is an intrinsic registered for all loaded methods " \
1896 "that are annotated with the @IntrinsicCandidate annotation, " \
1897 "and that " \
1898 "(3) no orphan methods exist for class C (i.e., methods for " \
1899 "which the VM declares an intrinsic but that are not declared "\
1900 "in the loaded class C. " \
1901 "Check (3) is available only in debug builds.") \
1902 \
1903 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1904 "Threshold small size (in bytes) for clearing arrays. " \
1905 "Anything this size or smaller may get converted to discrete " \
1906 "scalar stores.") \
1907 range(0, max_intx) \
1908 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1909 \
1910 product(ccstr, AllocateHeapAt, nullptr, \
1911 "Path to the directory where a temporary file will be created " \
1912 "to use as the backing store for Java Heap.") \
1913 \
1914 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1915 "Enable VM continuations support") \
1916 \
1917 develop(bool, LoomDeoptAfterThaw, false, \
1918 "Deopt stack after thaw") \
1919 \
1920 develop(bool, LoomVerifyAfterThaw, false, \
1921 "Verify stack after thaw") \
1922 \
1923 develop(bool, VerifyContinuations, false, \
1924 "Verify continuation consistency") \
1925 \
1926 develop(bool, UseContinuationFastPath, true, \
1927 "Use fast-path frame walking in continuations") \
1928 \
1929 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1930 "Run periodic metaspace verifications (0 - none, " \
1931 "1 - always, >1 every nth interval)") \
1932 \
1933 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1934 "On internal errors, include registers in error report.") \
1935 \
1936 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1937 "leverage profiling for table/lookup switch") \
1938 \
1939 develop(bool, TraceMemoryWriteback, false, \
1940 "Trace memory writeback operations") \
1941 \
1942 JFR_ONLY(product(bool, FlightRecorder, false, \
1943 "(Deprecated) Enable Flight Recorder")) \
1944 \
1945 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1946 "Flight Recorder options")) \
1947 \
1948 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1949 "Start flight recording with options")) \
1950 \
1951 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1952 "Use platform unstable time where supported for timestamps only") \
1953 \
1954 product(bool, UseEmptySlotsInSupers, true, \
1955 "(Deprecated) Allow allocating fields in empty slots of " \
1956 "super-classes") \
1957 \
1958 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1959 "Make nmethod barriers deoptimise a lot.") \
1960 \
1961 develop(bool, VerifyCrossModifyFence, \
1962 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1963 "Mark all threads after a safepoint, and clear on a modify " \
1964 "fence. Add cleanliness checks.") \
1965 \
1966 product(int, LockingMode, LM_LIGHTWEIGHT, \
1967 "Select locking mode: " \
1968 "0: monitors only (LM_MONITOR), " \
1969 "1: monitors & legacy stack-locking (LM_LEGACY), " \
1970 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT, default)") \
1971 range(0, 2) \
1972 \
1973 product(uint, TrimNativeHeapInterval, 0, \
1974 "Interval, in ms, at which the JVM will trim the native heap if " \
1975 "the platform supports that. Lower values will reclaim memory " \
1976 "more eagerly at the cost of higher overhead. A value of 0 " \
1977 "(default) disables native heap trimming.") \
1978 range(0, UINT_MAX) \
1979 \
1980 develop(bool, SimulateFullAddressSpace, false, \
1981 "Simulates a very populated, fragmented address space; no " \
1982 "targeted reservations will succeed.") \
1983 \
1984 product(bool, ProfileExceptionHandlers, true, \
1985 "Profile exception handlers") \
1986 \
1987 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
1988 "Unconditionally record nmethod dependencies on class " \
1989 "rewriting/transformation independently of the JVMTI " \
1990 "can_{retransform/redefine}_classes capabilities.") \
1991 \
1992 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
1993 "Use secondary supers cache during subtype checks.") \
1994 \
1995 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
1996 "Use hash table to lookup secondary supers.") \
1997 \
1998 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
1999 "Check that linear and hashed secondary lookups return the same result.") \
2000 \
2001 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
2002 "Use a terrible hash function in order to generate many collisions.") \
2003
2004 // end of RUNTIME_FLAGS
2005
2006 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2007 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2008 DECLARE_FLAGS(RUNTIME_FLAGS)
2009 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2010
2011 #endif // SHARE_RUNTIME_GLOBALS_HPP