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 *
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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(bool, UseCompactObjectHeaders, false, EXPERIMENTAL, \
132 "Use compact 64-bit object headers in 64-bit VM") \
133 \
134 product(int, ObjectAlignmentInBytes, 8, \
135 "Default object alignment in bytes, 8 is minimum") \
136 range(8, 256) \
137 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
138
139 #else
140 // !_LP64
141
142 #define LP64_RUNTIME_FLAGS(develop, \
143 develop_pd, \
144 product, \
145 product_pd, \
146 range, \
147 constraint)
148 const bool UseCompressedOops = false;
149 const bool UseCompressedClassPointers = false;
150 const bool UseCompactObjectHeaders = false;
151 const int ObjectAlignmentInBytes = 8;
152
153 #endif // _LP64
154
155 #define RUNTIME_FLAGS(develop, \
156 develop_pd, \
157 product, \
158 product_pd, \
159 range, \
160 constraint) \
161 \
162 develop(bool, CheckCompressedOops, true, \
163 "Generate checks in encoding/decoding code in debug VM") \
164 \
165 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
166 "Heap allocation steps through preferred address regions to find" \
167 " where it can allocate the heap. Number of steps to take per " \
168 "region.") \
169 range(1, max_uintx) \
170 \
171 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
172 "If nonzero set a timeout in milliseconds for handshakes") \
173 \
174 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
175 "Force safe construction, as if all fields are final.") \
176 \
177 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
178 "Enable normal processing of flags relating to field diagnostics")\
179 \
180 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
181 "Enable normal processing of flags relating to experimental " \
182 "features") \
183 \
184 product(bool, JavaMonitorsInStackTrace, true, \
185 "Print information about Java monitor locks when the stacks are " \
186 "dumped") \
187 \
188 product_pd(bool, UseLargePages, \
189 "Use large page memory") \
190 \
191 product_pd(bool, UseLargePagesIndividualAllocation, \
192 "Allocate large pages individually for better affinity") \
193 \
194 develop(bool, LargePagesIndividualAllocationInjectError, false, \
195 "Fail large pages individual allocation") \
196 \
197 product(bool, UseNUMA, false, \
198 "Use NUMA if available") \
199 \
200 product(bool, UseNUMAInterleaving, false, \
201 "Interleave memory across NUMA nodes if available") \
202 \
203 product(size_t, NUMAInterleaveGranularity, 2*M, \
204 "Granularity to use for NUMA interleaving on Windows OS") \
205 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
206 \
207 product(uintx, NUMAChunkResizeWeight, 20, \
208 "Percentage (0-100) used to weight the current sample when " \
209 "computing exponentially decaying average for " \
210 "AdaptiveNUMAChunkSizing") \
211 range(0, 100) \
212 \
213 product(size_t, NUMASpaceResizeRate, 1*G, \
214 "Do not reallocate more than this amount per collection") \
215 range(0, max_uintx) \
216 \
217 product(bool, UseAdaptiveNUMAChunkSizing, true, \
218 "Enable adaptive chunk sizing for NUMA") \
219 \
220 product(bool, NUMAStats, false, \
221 "Print NUMA stats in detailed heap information") \
222 \
223 product(bool, UseAES, false, \
224 "Control whether AES instructions are used when available") \
225 \
226 product(bool, UseFMA, false, \
227 "Control whether FMA instructions are used when available") \
228 \
229 product(bool, UseSHA, false, \
230 "Control whether SHA instructions are used when available") \
231 \
232 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
233 "Use intrinsics for GHASH versions of crypto") \
234 \
235 product(bool, UseBASE64Intrinsics, false, \
236 "Use intrinsics for java.util.Base64") \
237 \
238 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
239 "Use intrinsics for sun.security.util.math.intpoly") \
240 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
241 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
242 \
243 product(size_t, LargePageSizeInBytes, 0, \
244 "Maximum large page size used (0 will use the default large " \
245 "page size for the environment as the maximum)") \
246 range(0, max_uintx) \
247 \
248 product(size_t, LargePageHeapSizeThreshold, 128*M, \
249 "Use large pages if maximum heap is at least this big") \
250 range(0, max_uintx) \
251 \
252 product(bool, ForceTimeHighResolution, false, \
253 "Using high time resolution (for Win32 only)") \
254 \
255 develop(bool, TracePcPatching, false, \
256 "Trace usage of frame::patch_pc") \
257 \
258 develop(bool, TraceRelocator, false, \
259 "Trace the bytecode relocator") \
260 \
261 \
262 product(bool, SafepointALot, false, DIAGNOSTIC, \
263 "Generate a lot of safepoints. This works with " \
264 "GuaranteedSafepointInterval") \
265 \
266 product(bool, HandshakeALot, false, DIAGNOSTIC, \
267 "Generate a lot of handshakes. This works with " \
268 "GuaranteedSafepointInterval") \
269 \
270 product_pd(bool, BackgroundCompilation, \
271 "A thread requesting compilation is not blocked during " \
272 "compilation") \
273 \
274 product(bool, MethodFlushing, true, \
275 "Reclamation of compiled methods") \
276 \
277 develop(bool, VerifyStack, false, \
278 "Verify stack of each thread when it is entering a runtime call") \
279 \
280 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
281 "Make all non code cache addresses to be unreachable by " \
282 "forcing use of 64bit literal fixups") \
283 \
284 develop(bool, TraceDerivedPointers, false, \
285 "Trace traversal of derived pointers on stack") \
286 \
287 develop(bool, TraceCodeBlobStacks, false, \
288 "Trace stack-walk of codeblobs") \
289 \
290 develop(bool, PrintRewrites, false, \
291 "Print methods that are being rewritten") \
292 \
293 product(bool, UseInlineCaches, true, \
294 "Use Inline Caches for virtual calls ") \
295 \
296 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
297 "Inline arraycopy native that is known to be part of " \
298 "base library DLL") \
299 \
300 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
301 "Inline Object::hashCode() native that is known to be part " \
302 "of base library DLL") \
303 \
304 product(bool, InlineNatives, true, DIAGNOSTIC, \
305 "Inline natives that are known to be part of base library DLL") \
306 \
307 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
308 "Inline SinD, CosD, etc.") \
309 \
310 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
311 "Inline Class.isInstance, etc") \
312 \
313 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
314 "Inline Thread.currentThread, etc") \
315 \
316 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
317 "Inline memory ops (native methods) from Unsafe") \
318 \
319 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
320 "Use intrinsics for AES versions of crypto") \
321 \
322 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
323 "Use intrinsics for the paralleled version of AES/CTR crypto") \
324 \
325 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
326 "Use intrinsics for the vectorized version of ChaCha20") \
327 \
328 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
329 "Use intrinsics for MD5 crypto hash function") \
330 \
331 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
332 "Use intrinsics for SHA-1 crypto hash function. " \
333 "Requires that UseSHA is enabled.") \
334 \
335 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
336 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
337 "Requires that UseSHA is enabled.") \
338 \
339 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
340 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
341 "Requires that UseSHA is enabled.") \
342 \
343 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
344 "Use intrinsics for SHA3 crypto hash function. " \
345 "Requires that UseSHA is enabled.") \
346 \
347 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
348 "use intrinsics for java.util.zip.CRC32") \
349 \
350 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
351 "use intrinsics for java.util.zip.CRC32C") \
352 \
353 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
354 "use intrinsics for java.util.zip.Adler32") \
355 \
356 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
357 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
358 \
359 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
360 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
361 \
362 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
363 "Enables intrinsification of Math.copySign") \
364 \
365 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
366 "Enables intrinsification of Math.signum") \
367 \
368 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
369 "Use Compiler thread for compiler's stubs generation") \
370 \
371 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
372 "do not expand intrinsics whose (internal) names appear here") \
373 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
374 \
375 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
376 "Control intrinsics using a list of +/- (internal) names, " \
377 "separated by commas") \
378 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
379 \
380 develop(bool, TraceCallFixup, false, \
381 "Trace all call fixups") \
382 \
383 develop(bool, DeoptimizeALot, false, \
384 "Deoptimize at every exit from the runtime system") \
385 \
386 develop(ccstrlist, DeoptimizeOnlyAt, "", \
387 "A comma separated list of bcis to deoptimize at") \
388 \
389 develop(bool, DeoptimizeRandom, false, \
390 "Deoptimize random frames on random exit from the runtime system")\
391 \
392 develop(bool, ZombieALot, false, \
393 "Create non-entrant nmethods at exit from the runtime system") \
394 \
395 develop(bool, WalkStackALot, false, \
396 "Trace stack (no print) at every exit from the runtime system") \
397 \
398 develop(bool, DeoptimizeObjectsALot, false, \
399 "For testing purposes concurrent threads revert optimizations " \
400 "based on escape analysis at intervals given with " \
401 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
402 "with DeoptimizeObjectsALotThreadCountSingle and " \
403 "DeoptimizeObjectsALotThreadCountAll.") \
404 \
405 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
406 "Interval for DeoptimizeObjectsALot.") \
407 range(0, max_jlong) \
408 \
409 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
410 "The number of threads that revert optimizations based on " \
411 "escape analysis for a single thread if DeoptimizeObjectsALot " \
412 "is enabled. The target thread is selected round robin." ) \
413 range(0, max_jint) \
414 \
415 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
416 "The number of threads that revert optimizations based on " \
417 "escape analysis for all threads if DeoptimizeObjectsALot " \
418 "is enabled." ) \
419 range(0, max_jint) \
420 \
421 develop(bool, VerifyLastFrame, false, \
422 "Verify oops on last frame on entry to VM") \
423 \
424 product(bool, SafepointTimeout, false, \
425 "Time out and warn or fail after SafepointTimeoutDelay " \
426 "milliseconds if failed to reach safepoint") \
427 \
428 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
429 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
430 \
431 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
432 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
433 range(0, max_jlong) \
434 \
435 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
436 "Abort upon failure to complete VM operation promptly") \
437 \
438 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
439 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
440 range(0, max_intx) \
441 \
442 product(bool, MaxFDLimit, true, \
443 "Bump the number of file descriptors to maximum (Unix only)") \
444 \
445 product(bool, LogEvents, true, DIAGNOSTIC, \
446 "Enable the various ring buffer event logs") \
447 \
448 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
449 "Number of ring buffer event logs") \
450 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
451 \
452 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
453 "Enable the Java bytecode verifier for remote classes") \
454 \
455 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
456 "Enable the Java bytecode verifier for local classes") \
457 \
458 develop(bool, VerifyStackAtCalls, false, \
459 "Verify that the stack pointer is unchanged after calls") \
460 \
461 develop(bool, TraceJavaAssertions, false, \
462 "Trace java language assertions") \
463 \
464 develop(bool, VerifyCodeCache, false, \
465 "Verify code cache on memory allocation/deallocation") \
466 \
467 develop(bool, ZapResourceArea, trueInDebug, \
468 "Zap freed resource/arena space") \
469 \
470 develop(bool, ZapVMHandleArea, trueInDebug, \
471 "Zap freed VM handle space") \
472 \
473 develop(bool, ZapStackSegments, trueInDebug, \
474 "Zap allocated/freed stack segments") \
475 \
476 develop(bool, ZapUnusedHeapArea, trueInDebug, \
477 "Zap 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 product(bool, ClassUnloading, true, \
685 "Do unloading of classes") \
686 \
687 product(bool, ClassUnloadingWithConcurrentMark, true, \
688 "Do unloading of classes with a concurrent marking cycle") \
689 \
690 develop(bool, PrintSystemDictionaryAtExit, false, \
691 "Print the system dictionary at exit") \
692 \
693 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
694 "Print the class loader data graph at exit") \
695 \
696 product(bool, AllowParallelDefineClass, false, \
697 "Allow parallel defineClass requests for class loaders " \
698 "registering as parallel capable") \
699 \
700 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
701 "Disable the use of stack guard pages if the JVM is loaded " \
702 "on the primordial process thread") \
703 \
704 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
705 "Do JVMTI virtual thread mount/unmount transitions " \
706 "(disabling this flag implies no JVMTI events are posted)") \
707 \
708 /* notice: the max range value here is max_jint, not max_intx */ \
709 /* because of overflow issue */ \
710 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
711 "Async deflate idle monitors every so many milliseconds when " \
712 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
713 range(0, max_jint) \
714 \
715 /* notice: the max range value here is max_jint, not max_intx */ \
716 /* because of overflow issue */ \
717 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
718 "Async deflate idle monitors every so many milliseconds even " \
719 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
720 range(0, max_jint) \
721 \
722 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
723 "Used to estimate a variable ceiling based on number of threads " \
724 "for use with MonitorUsedDeflationThreshold (0 is off).") \
725 range(0, max_uintx) \
726 \
727 /* notice: the max range value here is max_jint, not max_intx */ \
728 /* because of overflow issue */ \
729 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
730 "The maximum number of monitors to deflate, unlink and delete " \
731 "at one time (minimum is 1024).") \
732 range(1024, max_jint) \
733 \
734 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
735 "The maximum number of monitors to unlink in one batch. ") \
736 range(1, max_jint) \
737 \
738 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
739 "Percentage of used monitors before triggering deflation (0 is " \
740 "off). The check is performed on AsyncDeflationInterval or " \
741 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
742 range(0, 100) \
743 \
744 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
745 "Max number of no progress async deflation attempts to tolerate " \
746 "before adjusting the in_use_list_ceiling up (0 is off).") \
747 range(0, max_uintx) \
748 \
749 product(intx, hashCode, 5, EXPERIMENTAL, \
750 "(Unstable) select hashCode generation algorithm") \
751 \
752 product(bool, ReduceSignalUsage, false, \
753 "Reduce the use of OS signals in Java and/or the VM") \
754 \
755 develop(bool, LoadLineNumberTables, true, \
756 "Tell whether the class file parser loads line number tables") \
757 \
758 develop(bool, LoadLocalVariableTables, true, \
759 "Tell whether the class file parser loads local variable tables") \
760 \
761 develop(bool, LoadLocalVariableTypeTables, true, \
762 "Tell whether the class file parser loads local variable type" \
763 "tables") \
764 \
765 product(bool, AllowUserSignalHandlers, false, \
766 "Application will install primary signal handlers for the JVM " \
767 "(Unix only)") \
768 \
769 product(bool, UseSignalChaining, true, \
770 "Use signal-chaining to invoke signal handlers installed " \
771 "by the application (Unix only)") \
772 \
773 product(bool, RestoreMXCSROnJNICalls, false, \
774 "Restore MXCSR when returning from JNI calls") \
775 \
776 product(bool, CheckJNICalls, false, \
777 "Verify all arguments to JNI calls") \
778 \
779 product(bool, UseFastJNIAccessors, true, \
780 "Use optimized versions of Get<Primitive>Field") \
781 \
782 product(intx, MaxJNILocalCapacity, 65536, \
783 "Maximum allowable local JNI handle capacity to " \
784 "EnsureLocalCapacity() and PushLocalFrame(), " \
785 "where <= 0 is unlimited, default: 65536") \
786 range(min_intx, max_intx) \
787 \
788 product(bool, EagerXrunInit, false, \
789 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
790 "but not all -Xrun libraries may support the state of the VM " \
791 "at this time") \
792 \
793 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
794 "Number of OutOfMemoryErrors preallocated with backtrace") \
795 \
796 product(bool, UseXMMForArrayCopy, false, \
797 "Use SSE2 MOVQ instruction for Arraycopy") \
798 \
799 develop(bool, PrintFieldLayout, false, \
800 "Print field layout for each class") \
801 \
802 /* Need to limit the extent of the padding to reasonable size. */\
803 /* 8K is well beyond the reasonable HW cache line size, even with */\
804 /* aggressive prefetching, while still leaving the room for segregating */\
805 /* among the distinct pages. */\
806 product(int, ContendedPaddingWidth, 128, \
807 "How many bytes to pad the fields/classes marked @Contended with")\
808 range(0, 8192) \
809 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
810 \
811 product(bool, EnableContended, true, \
812 "Enable @Contended annotation support") \
813 \
814 product(bool, RestrictContended, true, \
815 "Restrict @Contended to trusted classes") \
816 \
817 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
818 "Detect and take action upon identifying synchronization on " \
819 "value based classes. Modes: " \
820 "0: off; " \
821 "1: exit with fatal error; " \
822 "2: log message to stdout. Output file can be specified with " \
823 " -Xlog:valuebasedclasses. If JFR is running it will " \
824 " also generate JFR events.") \
825 range(0, 2) \
826 \
827 product(bool, ExitOnOutOfMemoryError, false, \
828 "JVM exits on the first occurrence of an out-of-memory error " \
829 "thrown from JVM") \
830 \
831 product(bool, CrashOnOutOfMemoryError, false, \
832 "JVM aborts, producing an error log and core/mini dump, on the " \
833 "first occurrence of an out-of-memory error thrown from JVM") \
834 \
835 product(intx, UserThreadWaitAttemptsAtExit, 30, \
836 "The number of times to wait for user threads to stop executing " \
837 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
838 "The maximum number of waits is 1000, to wait at most 10 " \
839 "seconds.") \
840 range(0, 1000) \
841 \
842 /* tracing */ \
843 \
844 develop(bool, StressRewriter, false, \
845 "Stress linktime bytecode rewriting") \
846 \
847 product(ccstr, TraceJVMTI, nullptr, \
848 "Trace flags for JVMTI functions and events") \
849 \
850 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
851 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
852 "This option can change an EMCP method into an obsolete method " \
853 "and can affect tests that expect specific methods to be EMCP. " \
854 "This option should be used with caution.") \
855 \
856 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
857 "(Deprecated) Allow redefinition to add and delete private " \
858 "static or final methods for compatibility with old releases") \
859 \
860 develop(bool, TraceBytecodes, false, \
861 "Trace bytecode execution") \
862 \
863 develop(bool, TraceBytecodesTruncated, false, \
864 "Truncate non control-flow bytecode when tracing bytecode") \
865 \
866 develop(bool, VerifyDependencies, trueInDebug, \
867 "Exercise and verify the compilation dependency mechanism") \
868 \
869 develop(bool, TraceNewOopMapGeneration, false, \
870 "Trace OopMapGeneration") \
871 \
872 develop(bool, TraceNewOopMapGenerationDetailed, false, \
873 "Trace OopMapGeneration: print detailed cell states") \
874 \
875 develop(bool, TimeOopMap, false, \
876 "Time calls to GenerateOopMap::compute_map() in sum") \
877 \
878 develop(bool, TimeOopMap2, false, \
879 "Time calls to GenerateOopMap::compute_map() individually") \
880 \
881 develop(bool, TraceOopMapRewrites, false, \
882 "Trace rewriting of methods during oop map generation") \
883 \
884 develop(bool, TraceFinalizerRegistration, false, \
885 "Trace registration of final references") \
886 \
887 product(bool, IgnoreEmptyClassPaths, false, \
888 "Ignore empty path elements in -classpath") \
889 \
890 product(bool, PrintHeapAtSIGBREAK, true, \
891 "Print heap layout in response to SIGBREAK") \
892 \
893 product(bool, PrintClassHistogram, false, MANAGEABLE, \
894 "Print a histogram of class instances") \
895 \
896 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
897 "The percentage of the used heap that the instances of a class " \
898 "must occupy for the class to generate a trace event") \
899 range(0.0, 100.0) \
900 \
901 /* JVMTI heap profiling */ \
902 \
903 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
904 "Verify memory system before JVMTI iteration") \
905 \
906 /* compiler */ \
907 \
908 /* notice: the max range value here is max_jint, not max_intx */ \
909 /* because of overflow issue */ \
910 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
911 "Number of compiler threads to run") \
912 range(0, max_jint) \
913 constraint(CICompilerCountConstraintFunc, AfterErgo) \
914 \
915 product(bool, UseDynamicNumberOfCompilerThreads, true, \
916 "Dynamically choose the number of parallel compiler threads") \
917 \
918 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
919 "Reduce the number of parallel compiler threads when they " \
920 "are not used") \
921 \
922 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
923 "Trace creation and removal of compiler threads") \
924 \
925 product(ccstr, LogClassLoadingCauseFor, nullptr, \
926 "Apply -Xlog:class+load+cause* to classes whose fully " \
927 "qualified name contains this string (\"*\" matches " \
928 "any class).") \
929 \
930 develop(bool, InjectCompilerCreationFailure, false, \
931 "Inject thread creation failures for " \
932 "UseDynamicNumberOfCompilerThreads") \
933 \
934 develop(bool, GenerateSynchronizationCode, true, \
935 "generate locking/unlocking code for synchronized methods and " \
936 "monitors") \
937 \
938 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
939 "Generate code for implicit null checks") \
940 \
941 product_pd(bool, TrapBasedNullChecks, \
942 "Generate code for null checks that uses a cmp and trap " \
943 "instruction raising SIGTRAP. This is only used if an access to" \
944 "null (+offset) will not raise a SIGSEGV, i.e.," \
945 "ImplicitNullChecks don't work (PPC64).") \
946 \
947 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
948 "Enable Thread SMR Statistics") \
949 \
950 product(bool, Inline, true, \
951 "Enable inlining") \
952 \
953 product(bool, ClipInlining, true, \
954 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
955 \
956 develop(bool, UseCHA, true, \
957 "Enable CHA") \
958 \
959 product(bool, UseTypeProfile, true, \
960 "Check interpreter profile for historically monomorphic calls") \
961 \
962 product(bool, PrintInlining, false, DIAGNOSTIC, \
963 "Print inlining optimizations") \
964 \
965 product(bool, UsePopCountInstruction, false, \
966 "Use population count instruction") \
967 \
968 develop(bool, TraceMethodReplacement, false, \
969 "Print when methods are replaced do to recompilation") \
970 \
971 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
972 "Minimum number of sweeper passes before an nmethod " \
973 "can be flushed") \
974 range(0, max_intx) \
975 \
976 develop(bool, StressCodeBuffers, false, \
977 "Exercise code buffer expansion and other rare state changes") \
978 \
979 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
980 "Generate extra debugging information for non-safepoints in " \
981 "nmethods") \
982 \
983 product(bool, PrintVMOptions, false, \
984 "Print flags that appeared on the command line") \
985 \
986 product(bool, IgnoreUnrecognizedVMOptions, false, \
987 "Ignore unrecognized VM options") \
988 \
989 product(bool, PrintCommandLineFlags, false, \
990 "Print flags specified on command line or set by ergonomics") \
991 \
992 product(bool, PrintFlagsInitial, false, \
993 "Print all VM flags before argument processing and exit VM") \
994 \
995 product(bool, PrintFlagsFinal, false, \
996 "Print all VM flags after argument and ergonomic processing") \
997 \
998 develop(bool, PrintFlagsWithComments, false, \
999 "Print all VM flags with default values and descriptions and " \
1000 "exit") \
1001 \
1002 product(bool, PrintFlagsRanges, false, \
1003 "Print VM flags and their ranges") \
1004 \
1005 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1006 "Use a mutex to serialize output to tty and LogFile") \
1007 \
1008 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1009 "Display all VM output on the tty, independently of LogVMOutput") \
1010 \
1011 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1012 "Save VM output to LogFile") \
1013 \
1014 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1015 "If LogVMOutput or LogCompilation is on, save VM output to " \
1016 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1017 \
1018 product(ccstr, ErrorFile, nullptr, \
1019 "If an error occurs, save the error data to this file " \
1020 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1021 \
1022 product(bool, ExtensiveErrorReports, \
1023 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1024 "Error reports are more extensive.") \
1025 \
1026 product(bool, DisplayVMOutputToStderr, false, \
1027 "If DisplayVMOutput is true, display all VM output to stderr") \
1028 \
1029 product(bool, DisplayVMOutputToStdout, false, \
1030 "If DisplayVMOutput is true, display all VM output to stdout") \
1031 \
1032 product(bool, ErrorFileToStderr, false, \
1033 "If true, error data is printed to stderr instead of a file") \
1034 \
1035 product(bool, ErrorFileToStdout, false, \
1036 "If true, error data is printed to stdout instead of a file") \
1037 \
1038 develop(bool, VerifyHeavyMonitors, false, \
1039 "Checks that no stack locking happens when using " \
1040 "-XX:LockingMode=0 (LM_MONITOR)") \
1041 \
1042 product(bool, PrintStringTableStatistics, false, \
1043 "print statistics about the StringTable and SymbolTable") \
1044 \
1045 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1046 "verify StringTable contents at exit") \
1047 \
1048 develop(bool, PrintSymbolTableSizeHistogram, false, \
1049 "print histogram of the symbol table") \
1050 \
1051 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1052 "Call fatal if this exception is thrown. Example: " \
1053 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1054 \
1055 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1056 "Call fatal if the exception pointed by AbortVMOnException " \
1057 "has this message") \
1058 \
1059 develop(bool, DebugVtables, false, \
1060 "add debugging code to vtable dispatch") \
1061 \
1062 product(bool, RangeCheckElimination, true, \
1063 "Eliminate range checks") \
1064 \
1065 develop_pd(bool, UncommonNullCast, \
1066 "track occurrences of null in casts; adjust compiler tactics") \
1067 \
1068 develop(bool, TypeProfileCasts, true, \
1069 "treat casts like calls for purposes of type profiling") \
1070 \
1071 develop(bool, TraceLivenessGen, false, \
1072 "Trace the generation of liveness analysis information") \
1073 \
1074 develop(bool, TraceLivenessQuery, false, \
1075 "Trace queries of liveness analysis information") \
1076 \
1077 develop(bool, CollectIndexSetStatistics, false, \
1078 "Collect information about IndexSets") \
1079 \
1080 develop(int, FastAllocateSizeLimit, 128*K, \
1081 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1082 "Inline allocations larger than this in doublewords must go slow")\
1083 \
1084 product_pd(bool, CompactStrings, \
1085 "Enable Strings to use single byte chars in backing store") \
1086 \
1087 product_pd(uint, TypeProfileLevel, \
1088 "=XYZ, with Z: Type profiling of arguments at call; " \
1089 "Y: Type profiling of return value at call; " \
1090 "X: Type profiling of parameters to methods; " \
1091 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1092 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1093 \
1094 product(int, TypeProfileArgsLimit, 2, \
1095 "max number of call arguments to consider for type profiling") \
1096 range(0, 16) \
1097 \
1098 product(int, TypeProfileParmsLimit, 2, \
1099 "max number of incoming parameters to consider for type profiling"\
1100 ", -1 for all") \
1101 range(-1, 64) \
1102 \
1103 /* statistics */ \
1104 develop(bool, CountCompiledCalls, false, \
1105 "Count method invocations") \
1106 \
1107 develop(bool, ICMissHistogram, false, \
1108 "Produce histogram of IC misses") \
1109 \
1110 /* interpreter */ \
1111 product_pd(bool, RewriteBytecodes, \
1112 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1113 \
1114 product_pd(bool, RewriteFrequentPairs, \
1115 "Rewrite frequently used bytecode pairs into a single bytecode") \
1116 \
1117 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1118 "Print the generated interpreter code") \
1119 \
1120 product(bool, UseInterpreter, true, \
1121 "Use interpreter for non-compiled methods") \
1122 \
1123 develop(bool, UseFastSignatureHandlers, true, \
1124 "Use fast signature handlers for native calls") \
1125 \
1126 product(bool, UseLoopCounter, true, \
1127 "Increment invocation counter on backward branch") \
1128 \
1129 product_pd(bool, UseOnStackReplacement, \
1130 "Use on stack replacement, calls runtime if invoc. counter " \
1131 "overflows in loop") \
1132 \
1133 develop(bool, TraceOnStackReplacement, false, \
1134 "Trace on stack replacement") \
1135 \
1136 product_pd(bool, PreferInterpreterNativeStubs, \
1137 "Use always interpreter stubs for native methods invoked via " \
1138 "interpreter") \
1139 \
1140 develop(bool, CountBytecodes, false, \
1141 "Count number of bytecodes executed") \
1142 \
1143 develop(bool, PrintBytecodeHistogram, false, \
1144 "Print histogram of the executed bytecodes") \
1145 \
1146 develop(bool, PrintBytecodePairHistogram, false, \
1147 "Print histogram of the executed bytecode pairs") \
1148 \
1149 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1150 "Print code generated for native method signature handlers") \
1151 \
1152 develop(bool, VerifyOops, false, \
1153 "Do plausibility checks for oops") \
1154 \
1155 develop(bool, CheckUnhandledOops, false, \
1156 "Check for unhandled oops in VM code") \
1157 \
1158 develop(bool, VerifyJNIFields, trueInDebug, \
1159 "Verify jfieldIDs for instance fields") \
1160 \
1161 develop(bool, VerifyFPU, false, \
1162 "Verify FPU state (check for NaN's, etc.)") \
1163 \
1164 develop(bool, VerifyActivationFrameSize, false, \
1165 "Verify that activation frame didn't become smaller than its " \
1166 "minimal size") \
1167 \
1168 develop(bool, TraceFrequencyInlining, false, \
1169 "Trace frequency based inlining") \
1170 \
1171 develop_pd(bool, InlineIntrinsics, \
1172 "Use intrinsics in Interpreter that can be statically resolved") \
1173 \
1174 product_pd(bool, ProfileInterpreter, \
1175 "Profile at the bytecode level during interpretation") \
1176 \
1177 develop_pd(bool, ProfileTraps, \
1178 "Profile deoptimization traps at the bytecode level") \
1179 \
1180 product(intx, ProfileMaturityPercentage, 20, \
1181 "number of method invocations/branches (expressed as % of " \
1182 "CompileThreshold) before using the method's profile") \
1183 range(0, 100) \
1184 \
1185 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1186 "Print the results of +ProfileInterpreter at end of run") \
1187 \
1188 develop(bool, VerifyDataPointer, trueInDebug, \
1189 "Verify the method data pointer during interpreter profiling") \
1190 \
1191 develop(bool, CrashGCForDumpingJavaThread, false, \
1192 "Manually make GC thread crash then dump java stack trace; " \
1193 "Test only") \
1194 \
1195 /* compilation */ \
1196 product(bool, UseCompiler, true, \
1197 "Use Just-In-Time compilation") \
1198 \
1199 product(bool, AlwaysCompileLoopMethods, false, \
1200 "When using recompilation, never interpret methods " \
1201 "containing loops") \
1202 \
1203 product(int, AllocatePrefetchStyle, 1, \
1204 "0 = no prefetch, " \
1205 "1 = generate prefetch instructions for each allocation, " \
1206 "2 = use TLAB watermark to gate allocation prefetch, " \
1207 "3 = generate one prefetch instruction per cache line") \
1208 range(0, 3) \
1209 \
1210 product(int, AllocatePrefetchDistance, -1, \
1211 "Distance to prefetch ahead of allocation pointer. " \
1212 "-1: use system-specific value (automatically determined") \
1213 range(-1, 512) \
1214 \
1215 product(int, AllocatePrefetchLines, 3, \
1216 "Number of lines to prefetch ahead of array allocation pointer") \
1217 range(1, 64) \
1218 \
1219 product(int, AllocateInstancePrefetchLines, 1, \
1220 "Number of lines to prefetch ahead of instance allocation " \
1221 "pointer") \
1222 range(1, 64) \
1223 \
1224 product(int, AllocatePrefetchStepSize, 16, \
1225 "Step size in bytes of sequential prefetch instructions") \
1226 range(1, 512) \
1227 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1228 \
1229 product(intx, AllocatePrefetchInstr, 0, \
1230 "Select instruction to prefetch ahead of allocation pointer") \
1231 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1232 \
1233 /* deoptimization */ \
1234 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1235 "Trace deoptimization") \
1236 \
1237 develop(bool, PrintDeoptimizationDetails, false, \
1238 "Print more information about deoptimization") \
1239 \
1240 develop(bool, DebugDeoptimization, false, \
1241 "Tracing various information while debugging deoptimization") \
1242 \
1243 product(double, SelfDestructTimer, 0.0, \
1244 "Will cause VM to terminate after a given time " \
1245 "(in fractional minutes) " \
1246 "(0.0 means off)") \
1247 range(0.0, (double)max_intx) \
1248 \
1249 product(int, MaxJavaStackTraceDepth, 1024, \
1250 "The maximum number of lines in the stack trace for Java " \
1251 "exceptions (0 means all)") \
1252 range(0, max_jint/2) \
1253 \
1254 /* notice: the max range value here is max_jint, not max_intx */ \
1255 /* because of overflow issue */ \
1256 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1257 "Guarantee a safepoint (at least) every so many milliseconds " \
1258 "(0 means none)") \
1259 range(0, max_jint) \
1260 \
1261 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1262 "Wake the ServiceThread to do periodic cleanup checks every so " \
1263 "many milliseconds (0 means none)") \
1264 range(0, max_jint) \
1265 \
1266 product(double, SafepointTimeoutDelay, 10000, \
1267 "Delay in milliseconds for option SafepointTimeout; " \
1268 "supports sub-millisecond resolution with fractional values.") \
1269 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1270 \
1271 product(bool, UseSystemMemoryBarrier, false, \
1272 "Try to enable system memory barrier if supported by OS") \
1273 \
1274 product(intx, NmethodSweepActivity, 4, \
1275 "Removes cold nmethods from code cache if > 0. Higher values " \
1276 "result in more aggressive sweeping") \
1277 range(0, 2000) \
1278 \
1279 develop(intx, MallocCatchPtr, -1, \
1280 "Hit breakpoint when mallocing/freeing this pointer") \
1281 \
1282 develop(int, StackPrintLimit, 100, \
1283 "number of stack frames to print in VM-level stack dump") \
1284 \
1285 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1286 "max number of compiled code units to print in error log") \
1287 range(0, VMError::max_error_log_print_code) \
1288 \
1289 develop(int, MaxElementPrintSize, 256, \
1290 "maximum number of elements to print") \
1291 \
1292 develop(int, MaxStringPrintSize, 256, \
1293 "maximum number of characters to print for a java.lang.String " \
1294 "in the VM. If exceeded, an abridged version of the string is " \
1295 "printed with the middle of the string elided.") \
1296 range(2, O_BUFLEN) \
1297 \
1298 develop(intx, MaxSubklassPrintSize, 4, \
1299 "maximum number of subklasses to print when printing klass") \
1300 \
1301 develop(intx, MaxForceInlineLevel, 100, \
1302 "maximum number of nested calls that are forced for inlining " \
1303 "(using CompileCommand or marked w/ @ForceInline)") \
1304 range(0, max_jint) \
1305 \
1306 develop(intx, MethodHistogramCutoff, 100, \
1307 "The cutoff value for method invocation histogram (+CountCalls)") \
1308 \
1309 develop(intx, DeoptimizeALotInterval, 5, \
1310 "Number of exits until DeoptimizeALot kicks in") \
1311 \
1312 develop(intx, ZombieALotInterval, 5, \
1313 "Number of exits until ZombieALot kicks in") \
1314 \
1315 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1316 "Limit malloc allocation size from VM. Reaching a limit will " \
1317 "trigger an action (see flag). This feature requires " \
1318 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1319 "Usage:" \
1320 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1321 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1322 "sets one or more category-specific limits." \
1323 "<flag> defines the action upon reaching the limit:" \
1324 "\"fatal\": end VM with a fatal error at the allocation site" \
1325 "\"oom\" : will mimic a native OOM" \
1326 "If <flag> is omitted, \"fatal\" is the default." \
1327 "Examples:\n" \
1328 "-XX:MallocLimit=2g" \
1329 "-XX:MallocLimit=2g:oom" \
1330 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1331 \
1332 product(intx, TypeProfileWidth, 2, \
1333 "Number of receiver types to record in call/cast profile") \
1334 range(0, 8) \
1335 \
1336 develop(intx, BciProfileWidth, 2, \
1337 "Number of return bci's to record in ret profile") \
1338 \
1339 product(intx, PerMethodRecompilationCutoff, 400, \
1340 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1341 range(-1, max_intx) \
1342 \
1343 product(intx, PerBytecodeRecompilationCutoff, 200, \
1344 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1345 range(-1, max_intx) \
1346 \
1347 product(intx, PerMethodTrapLimit, 100, \
1348 "Limit on traps (of one kind) in a method (includes inlines)") \
1349 range(0, max_jint) \
1350 \
1351 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1352 "Limit on speculative traps (of one kind) in a method " \
1353 "(includes inlines)") \
1354 range(0, max_jint) \
1355 \
1356 product(intx, PerBytecodeTrapLimit, 4, \
1357 "Limit on traps (of one kind) at a particular BCI") \
1358 range(0, max_jint) \
1359 \
1360 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1361 "Extra method data trap entries for speculation") \
1362 \
1363 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1364 "Ratio of call site execution to caller method invocation") \
1365 \
1366 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1367 "Minimum ratio of call site execution to caller method" \
1368 "invocation to be considered for inlining") \
1369 \
1370 develop(intx, InlineThrowCount, 50, \
1371 "Force inlining of interpreted methods that throw this often") \
1372 range(0, max_jint) \
1373 \
1374 develop(intx, InlineThrowMaxSize, 200, \
1375 "Force inlining of throwing methods smaller than this") \
1376 range(0, max_jint) \
1377 \
1378 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1379 "Initial threshold (in bytes) at which a garbage collection " \
1380 "is done to reduce Metaspace usage") \
1381 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1382 \
1383 product(size_t, MaxMetaspaceSize, max_uintx, \
1384 "Maximum size of Metaspaces (in bytes)") \
1385 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1386 \
1387 product(size_t, CompressedClassSpaceSize, 1*G, \
1388 "Maximum size of class area in Metaspace when compressed " \
1389 "class pointers are used") \
1390 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1391 \
1392 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1393 "Force the class space to be allocated at this address or " \
1394 "fails VM initialization (requires -Xshare=off.") \
1395 \
1396 develop(bool, RandomizeClassSpaceLocation, true, \
1397 "Randomize location of class space.") \
1398 \
1399 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1400 "Print metaspace statistics upon VM exit.") \
1401 \
1402 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1403 "The minimum percentage of heap free after GC to avoid expansion."\
1404 " For most GCs this applies to the old generation. In G1 and" \
1405 " ParallelGC it applies to the whole heap.") \
1406 range(0, 100) \
1407 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1408 \
1409 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1410 "The maximum percentage of heap free after GC to avoid shrinking."\
1411 " For most GCs this applies to the old generation. In G1 and" \
1412 " ParallelGC it applies to the whole heap.") \
1413 range(0, 100) \
1414 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1415 \
1416 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1417 "Number of milliseconds per MB of free space in the heap") \
1418 range(0, max_intx) \
1419 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1420 \
1421 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1422 "The minimum change in heap space due to GC (in bytes)") \
1423 range(0, max_uintx) \
1424 \
1425 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1426 "The minimum expansion of Metaspace (in bytes)") \
1427 range(0, max_uintx) \
1428 \
1429 product(uint, MaxMetaspaceFreeRatio, 70, \
1430 "The maximum percentage of Metaspace free after GC to avoid " \
1431 "shrinking") \
1432 range(0, 100) \
1433 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1434 \
1435 product(uint, MinMetaspaceFreeRatio, 40, \
1436 "The minimum percentage of Metaspace free after GC to avoid " \
1437 "expansion") \
1438 range(0, 99) \
1439 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1440 \
1441 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1442 "The maximum expansion of Metaspace without full GC (in bytes)") \
1443 range(0, max_uintx) \
1444 \
1445 /* stack parameters */ \
1446 product_pd(intx, StackYellowPages, \
1447 "Number of yellow zone (recoverable overflows) pages of size " \
1448 "4KB. If pages are bigger yellow zone is aligned up.") \
1449 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1450 \
1451 product_pd(intx, StackRedPages, \
1452 "Number of red zone (unrecoverable overflows) pages of size " \
1453 "4KB. If pages are bigger red zone is aligned up.") \
1454 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1455 \
1456 product_pd(intx, StackReservedPages, \
1457 "Number of reserved zone (reserved to annotated methods) pages" \
1458 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1459 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1460 \
1461 product(bool, RestrictReservedStack, true, \
1462 "Restrict @ReservedStackAccess to trusted classes") \
1463 \
1464 /* greater stack shadow pages can't generate instruction to bang stack */ \
1465 product_pd(intx, StackShadowPages, \
1466 "Number of shadow zone (for overflow checking) pages of size " \
1467 "4KB. If pages are bigger shadow zone is aligned up. " \
1468 "This should exceed the depth of the VM and native call stack.") \
1469 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1470 \
1471 product_pd(intx, ThreadStackSize, \
1472 "Thread Stack Size (in Kbytes)") \
1473 range(0, 1 * M) \
1474 \
1475 product_pd(intx, VMThreadStackSize, \
1476 "Non-Java Thread Stack Size (in Kbytes)") \
1477 range(0, max_intx/(1 * K)) \
1478 \
1479 product_pd(intx, CompilerThreadStackSize, \
1480 "Compiler Thread Stack Size (in Kbytes)") \
1481 range(0, max_intx/(1 * K)) \
1482 \
1483 develop_pd(size_t, JVMInvokeMethodSlack, \
1484 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1485 \
1486 /* code cache parameters */ \
1487 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1488 "Code cache segment size (in bytes) - smallest unit of " \
1489 "allocation") \
1490 range(1, 1024) \
1491 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1492 \
1493 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1494 "Code entry alignment for generated code (in bytes)") \
1495 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1496 \
1497 product_pd(intx, OptoLoopAlignment, \
1498 "Align inner loops to zero relative to this modulus") \
1499 range(1, 128) \
1500 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1501 \
1502 product_pd(uintx, InitialCodeCacheSize, \
1503 "Initial code cache size (in bytes)") \
1504 constraint(VMPageSizeConstraintFunc, AtParse) \
1505 \
1506 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1507 "Minimum code cache size (in bytes) required to start VM.") \
1508 range(0, max_uintx) \
1509 \
1510 product(bool, SegmentedCodeCache, false, \
1511 "Use a segmented code cache") \
1512 \
1513 product_pd(uintx, ReservedCodeCacheSize, \
1514 "Reserved code cache size (in bytes) - maximum code cache size") \
1515 constraint(VMPageSizeConstraintFunc, AtParse) \
1516 \
1517 product_pd(uintx, NonProfiledCodeHeapSize, \
1518 "Size of code heap with non-profiled methods (in bytes)") \
1519 range(0, max_uintx) \
1520 \
1521 product_pd(uintx, ProfiledCodeHeapSize, \
1522 "Size of code heap with profiled methods (in bytes)") \
1523 range(0, max_uintx) \
1524 \
1525 product_pd(uintx, NonNMethodCodeHeapSize, \
1526 "Size of code heap with non-nmethods (in bytes)") \
1527 constraint(VMPageSizeConstraintFunc, AtParse) \
1528 \
1529 product_pd(uintx, CodeCacheExpansionSize, \
1530 "Code cache expansion size (in bytes)") \
1531 range(32*K, max_uintx) \
1532 \
1533 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1534 "Minimum number of segments in a code cache block") \
1535 range(1, 100) \
1536 \
1537 develop(bool, ExitOnFullCodeCache, false, \
1538 "Exit the VM if we fill the code cache") \
1539 \
1540 product(bool, UseCodeCacheFlushing, true, \
1541 "Remove cold/old nmethods from the code cache") \
1542 \
1543 product(double, SweeperThreshold, 15.0, \
1544 "Threshold when a code cache unloading GC is invoked." \
1545 "Value is percentage of ReservedCodeCacheSize.") \
1546 range(0.0, 100.0) \
1547 \
1548 product(uintx, StartAggressiveSweepingAt, 10, \
1549 "Start aggressive sweeping if X[%] of the code cache is free." \
1550 "Segmented code cache: X[%] of the non-profiled heap." \
1551 "Non-segmented code cache: X[%] of the total code cache") \
1552 range(0, 100) \
1553 \
1554 /* interpreter debugging */ \
1555 develop(intx, BinarySwitchThreshold, 5, \
1556 "Minimal number of lookupswitch entries for rewriting to binary " \
1557 "switch") \
1558 \
1559 develop(intx, StopInterpreterAt, 0, \
1560 "Stop interpreter execution at specified bytecode number") \
1561 \
1562 develop(intx, TraceBytecodesAt, 0, \
1563 "Trace bytecodes starting with specified bytecode number") \
1564 \
1565 develop(intx, TraceBytecodesStopAt, 0, \
1566 "Stop bytecode tracing at the specified bytecode number") \
1567 \
1568 /* Priorities */ \
1569 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1570 \
1571 product(int, ThreadPriorityPolicy, 0, \
1572 "0 : Normal. "\
1573 " VM chooses priorities that are appropriate for normal "\
1574 " applications. "\
1575 " On Windows applications are allowed to use higher native "\
1576 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1577 " not use the highest possible native priority, "\
1578 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1579 " system threads. On Linux thread priorities are ignored "\
1580 " because the OS does not support static priority in "\
1581 " SCHED_OTHER scheduling class which is the only choice for "\
1582 " non-root, non-realtime applications. "\
1583 "1 : Aggressive. "\
1584 " Java thread priorities map over to the entire range of "\
1585 " native thread priorities. Higher Java thread priorities map "\
1586 " to higher native thread priorities. This policy should be "\
1587 " used with care, as sometimes it can cause performance "\
1588 " degradation in the application and/or the entire system. On "\
1589 " Linux/BSD/macOS this policy requires root privilege or an "\
1590 " extended capability.") \
1591 range(0, 1) \
1592 \
1593 product(bool, ThreadPriorityVerbose, false, \
1594 "Print priority changes") \
1595 \
1596 product(int, CompilerThreadPriority, -1, \
1597 "The native priority at which compiler threads should run " \
1598 "(-1 means no change)") \
1599 range(min_jint, max_jint) \
1600 \
1601 product(int, VMThreadPriority, -1, \
1602 "The native priority at which the VM thread should run " \
1603 "(-1 means no change)") \
1604 range(-1, 127) \
1605 \
1606 product(int, JavaPriority1_To_OSPriority, -1, \
1607 "Map Java priorities to OS priorities") \
1608 range(-1, 127) \
1609 \
1610 product(int, JavaPriority2_To_OSPriority, -1, \
1611 "Map Java priorities to OS priorities") \
1612 range(-1, 127) \
1613 \
1614 product(int, JavaPriority3_To_OSPriority, -1, \
1615 "Map Java priorities to OS priorities") \
1616 range(-1, 127) \
1617 \
1618 product(int, JavaPriority4_To_OSPriority, -1, \
1619 "Map Java priorities to OS priorities") \
1620 range(-1, 127) \
1621 \
1622 product(int, JavaPriority5_To_OSPriority, -1, \
1623 "Map Java priorities to OS priorities") \
1624 range(-1, 127) \
1625 \
1626 product(int, JavaPriority6_To_OSPriority, -1, \
1627 "Map Java priorities to OS priorities") \
1628 range(-1, 127) \
1629 \
1630 product(int, JavaPriority7_To_OSPriority, -1, \
1631 "Map Java priorities to OS priorities") \
1632 range(-1, 127) \
1633 \
1634 product(int, JavaPriority8_To_OSPriority, -1, \
1635 "Map Java priorities to OS priorities") \
1636 range(-1, 127) \
1637 \
1638 product(int, JavaPriority9_To_OSPriority, -1, \
1639 "Map Java priorities to OS priorities") \
1640 range(-1, 127) \
1641 \
1642 product(int, JavaPriority10_To_OSPriority,-1, \
1643 "Map Java priorities to OS priorities") \
1644 range(-1, 127) \
1645 \
1646 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1647 "Java thread priority 10 maps to critical scheduling priority") \
1648 \
1649 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1650 "Compiler thread(s) run at critical scheduling priority") \
1651 \
1652 develop(intx, NewCodeParameter, 0, \
1653 "Testing Only: Create a dedicated integer parameter before " \
1654 "putback") \
1655 \
1656 /* new oopmap storage allocation */ \
1657 develop(intx, MinOopMapAllocation, 8, \
1658 "Minimum number of OopMap entries in an OopMapSet") \
1659 \
1660 /* recompilation */ \
1661 product_pd(intx, CompileThreshold, \
1662 "number of interpreted method invocations before (re-)compiling") \
1663 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1664 \
1665 product_pd(bool, TieredCompilation, \
1666 "Enable tiered compilation") \
1667 \
1668 /* Properties for Java libraries */ \
1669 \
1670 product(uint64_t, MaxDirectMemorySize, 0, \
1671 "Maximum total size of NIO direct-buffer allocations. " \
1672 "Ignored if not explicitly set.") \
1673 range(0, max_jlong) \
1674 \
1675 /* Flags used for temporary code during development */ \
1676 \
1677 product(bool, UseNewCode, false, DIAGNOSTIC, \
1678 "Testing Only: Use the new version while testing") \
1679 \
1680 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1681 "Testing Only: Use the new version while testing") \
1682 \
1683 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1684 "Testing Only: Use the new version while testing") \
1685 \
1686 develop(bool, UseDebuggerErgo, false, \
1687 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1688 "Turns on the other UseDebuggerErgo* flags") \
1689 \
1690 develop(bool, UseDebuggerErgo1, false, \
1691 "Debugging Only: Enable workarounds for debugger induced " \
1692 "os::processor_id() >= os::processor_count() problems") \
1693 \
1694 develop(bool, UseDebuggerErgo2, false, \
1695 "Debugging Only: Limit the number of spawned JVM threads") \
1696 \
1697 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1698 "Enable JVMTI asserts related to stack depth checks") \
1699 \
1700 /* flags for performance data collection */ \
1701 \
1702 product(bool, UsePerfData, true, \
1703 "Flag to disable jvmstat instrumentation for performance testing "\
1704 "and problem isolation purposes") \
1705 \
1706 product(bool, PerfDataSaveToFile, false, \
1707 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1708 \
1709 product(ccstr, PerfDataSaveFile, nullptr, \
1710 "Save PerfData memory to the specified absolute pathname. " \
1711 "The string %p in the file name (if present) " \
1712 "will be replaced by pid") \
1713 \
1714 product(int, PerfDataSamplingInterval, 50, \
1715 "Data sampling interval (in milliseconds)") \
1716 range(PeriodicTask::min_interval, max_jint) \
1717 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1718 \
1719 product(bool, PerfDisableSharedMem, false, \
1720 "Store performance data in standard memory") \
1721 \
1722 product(int, PerfDataMemorySize, 32*K, \
1723 "Size of performance data memory region. Will be rounded " \
1724 "up to a multiple of the native os page size.") \
1725 range(128, 32*64*K) \
1726 \
1727 product(int, PerfMaxStringConstLength, 1024, \
1728 "Maximum PerfStringConstant string length before truncation") \
1729 range(32, 32*K) \
1730 \
1731 product(bool, PerfAllowAtExitRegistration, false, \
1732 "Allow registration of atexit() methods") \
1733 \
1734 product(bool, PerfBypassFileSystemCheck, false, \
1735 "Bypass Win32 file system criteria checks (Windows Only)") \
1736 \
1737 product(int, UnguardOnExecutionViolation, 0, \
1738 "Unguard page and retry on no-execute fault (Win32 only) " \
1739 "0=off, 1=conservative, 2=aggressive") \
1740 range(0, 2) \
1741 \
1742 /* Serviceability Support */ \
1743 \
1744 product(bool, ManagementServer, false, \
1745 "Create JMX Management Server") \
1746 \
1747 product(bool, DisableAttachMechanism, false, \
1748 "Disable mechanism that allows tools to attach to this VM") \
1749 \
1750 product(bool, StartAttachListener, false, \
1751 "Always start Attach Listener at VM startup") \
1752 \
1753 product(bool, EnableDynamicAgentLoading, true, \
1754 "Allow tools to load agents with the attach mechanism") \
1755 \
1756 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1757 "Print java.util.concurrent locks in thread dump") \
1758 \
1759 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1760 "Print generated stub code for method handles") \
1761 \
1762 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1763 "perform extra checks when constructing method handles") \
1764 \
1765 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1766 "show method handle implementation frames (usually hidden)") \
1767 \
1768 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1769 "show virtual threads' carrier frames in exceptions") \
1770 \
1771 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1772 "trust final non-static declarations for constant folding") \
1773 \
1774 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1775 "Optimize loads from stable fields (marked w/ @Stable)") \
1776 \
1777 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1778 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1779 "resolved before the bootstrap method is called; 1: when a BSM " \
1780 "that may accept a BootstrapCallInfo is detected, use that API " \
1781 "to pass BSM arguments, which allows the BSM to delay their " \
1782 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1783 "via that API, instead of with the eagerly-resolved array.") \
1784 \
1785 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1786 "Causes the VM to pause at startup time and wait for the pause " \
1787 "file to be removed (default: ./vm.paused.<pid>)") \
1788 \
1789 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1790 "The file to create and for whose removal to await when pausing " \
1791 "at startup. (default: ./vm.paused.<pid>)") \
1792 \
1793 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1794 "Pause and wait for keypress on exit if a debugger is attached") \
1795 \
1796 product(bool, DTraceMethodProbes, false, \
1797 "Enable dtrace tool probes for method-entry and method-exit") \
1798 \
1799 product(bool, DTraceAllocProbes, false, \
1800 "Enable dtrace tool probes for object allocation") \
1801 \
1802 product(bool, DTraceMonitorProbes, false, \
1803 "Enable dtrace tool probes for monitor events") \
1804 \
1805 product(bool, RelaxAccessControlCheck, false, \
1806 "Relax the access control checks in the verifier") \
1807 \
1808 product(uintx, StringTableSize, defaultStringTableSize, \
1809 "Number of buckets in the interned String table " \
1810 "(will be rounded to nearest higher power of 2)") \
1811 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1812 \
1813 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1814 "Number of buckets in the JVM internal Symbol table") \
1815 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1816 \
1817 product(bool, UseStringDeduplication, false, \
1818 "Use string deduplication") \
1819 \
1820 product(uint, StringDeduplicationAgeThreshold, 3, \
1821 "A string must reach this age (or be promoted to an old region) " \
1822 "to be considered for deduplication") \
1823 range(1, markWord::max_age) \
1824 \
1825 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1826 "Approximate initial number of buckets in the table") \
1827 range(1, 1 * G) \
1828 \
1829 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1830 "Entries per bucket above which the table should be expanded") \
1831 range(0.1, 1000.0) \
1832 \
1833 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1834 "Entries per bucket below which the table should be shrunk") \
1835 range(0.01, 100.0) \
1836 \
1837 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1838 "Desired entries per bucket when resizing the table") \
1839 range(0.01, 1000.0) \
1840 \
1841 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1842 "Minimum number of dead table entries for cleaning the table") \
1843 \
1844 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1845 "Minimum percentage of dead table entries for cleaning the table") \
1846 range(1, 100) \
1847 \
1848 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1849 "Force more frequent table resizing") \
1850 \
1851 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1852 "Seed for the table hashing function; 0 requests computed seed") \
1853 \
1854 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1855 "Enable internal testing APIs") \
1856 \
1857 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1858 "Accesses to all variables should always be atomic") \
1859 \
1860 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1861 "Use unaligned memory accesses in Unsafe") \
1862 \
1863 product_pd(bool, PreserveFramePointer, \
1864 "Use the FP register for holding the frame pointer " \
1865 "and not as a general purpose register.") \
1866 \
1867 product(size_t, AsyncLogBufferSize, 2*M, \
1868 "Memory budget (in bytes) for the buffer of Asynchronous " \
1869 "Logging (-Xlog:async).") \
1870 range(100*K, 50*M) \
1871 \
1872 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1873 "When a class C is loaded, check that " \
1874 "(1) all intrinsics defined by the VM for class C are present "\
1875 "in the loaded class file and are marked with the " \
1876 "@IntrinsicCandidate annotation, that " \
1877 "(2) there is an intrinsic registered for all loaded methods " \
1878 "that are annotated with the @IntrinsicCandidate annotation, " \
1879 "and that " \
1880 "(3) no orphan methods exist for class C (i.e., methods for " \
1881 "which the VM declares an intrinsic but that are not declared "\
1882 "in the loaded class C. " \
1883 "Check (3) is available only in debug builds.") \
1884 \
1885 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1886 "Threshold small size (in bytes) for clearing arrays. " \
1887 "Anything this size or smaller may get converted to discrete " \
1888 "scalar stores.") \
1889 range(0, max_intx) \
1890 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1891 \
1892 product(ccstr, AllocateHeapAt, nullptr, \
1893 "Path to the directory where a temporary file will be created " \
1894 "to use as the backing store for Java Heap.") \
1895 \
1896 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1897 "Enable VM continuations support") \
1898 \
1899 develop(bool, LoomDeoptAfterThaw, false, \
1900 "Deopt stack after thaw") \
1901 \
1902 develop(bool, LoomVerifyAfterThaw, false, \
1903 "Verify stack after thaw") \
1904 \
1905 develop(bool, VerifyContinuations, true, \
1906 "Verify continuation consistency") \
1907 \
1908 develop(bool, UseContinuationFastPath, true, \
1909 "Use fast-path frame walking in continuations") \
1910 \
1911 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1912 "Run periodic metaspace verifications (0 - none, " \
1913 "1 - always, >1 every nth interval)") \
1914 \
1915 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1916 "On internal errors, include registers in error report.") \
1917 \
1918 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1919 "leverage profiling for table/lookup switch") \
1920 \
1921 develop(bool, TraceMemoryWriteback, false, \
1922 "Trace memory writeback operations") \
1923 \
1924 JFR_ONLY(product(bool, FlightRecorder, false, \
1925 "(Deprecated) Enable Flight Recorder")) \
1926 \
1927 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1928 "Flight Recorder options")) \
1929 \
1930 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1931 "Start flight recording with options")) \
1932 \
1933 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1934 "Use platform unstable time where supported for timestamps only") \
1935 \
1936 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1937 "Make nmethod barriers deoptimise a lot.") \
1938 \
1939 develop(bool, VerifyCrossModifyFence, \
1940 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1941 "Mark all threads after a safepoint, and clear on a modify " \
1942 "fence. Add cleanliness checks.") \
1943 \
1944 product(int, LockingMode, LM_LIGHTWEIGHT, \
1945 "(Deprecated) Select locking mode: " \
1946 "0: (Deprecated) monitors only (LM_MONITOR), " \
1947 "1: (Deprecated) monitors & legacy stack-locking (LM_LEGACY), " \
1948 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT, default)") \
1949 range(0, 2) \
1950 \
1951 product(bool, UseObjectMonitorTable, false, DIAGNOSTIC, \
1952 "With Lightweight Locking mode, use a table to record inflated " \
1953 "monitors rather than the first word of the object.") \
1954 \
1955 product(int, LightweightFastLockingSpins, 13, DIAGNOSTIC, \
1956 "Specifies the number of times lightweight fast locking will " \
1957 "attempt to CAS the markWord before inflating. Between each " \
1958 "CAS it will spin for exponentially more time, resulting in " \
1959 "a total number of spins on the order of O(2^value)") \
1960 range(1, 30) \
1961 \
1962 product(uint, TrimNativeHeapInterval, 0, \
1963 "Interval, in ms, at which the JVM will trim the native heap if " \
1964 "the platform supports that. Lower values will reclaim memory " \
1965 "more eagerly at the cost of higher overhead. A value of 0 " \
1966 "(default) disables native heap trimming.") \
1967 range(0, UINT_MAX) \
1968 \
1969 develop(bool, SimulateFullAddressSpace, false, \
1970 "Simulates a very populated, fragmented address space; no " \
1971 "targeted reservations will succeed.") \
1972 \
1973 product(bool, ProfileExceptionHandlers, true, \
1974 "Profile exception handlers") \
1975 \
1976 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
1977 "Unconditionally record nmethod dependencies on class " \
1978 "rewriting/transformation independently of the JVMTI " \
1979 "can_{retransform/redefine}_classes capabilities.") \
1980 \
1981 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
1982 "Use secondary supers cache during subtype checks.") \
1983 \
1984 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
1985 "Use hash table to lookup secondary supers.") \
1986 \
1987 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
1988 "Check that linear and hashed secondary lookups return the same result.") \
1989 \
1990 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
1991 "Use a terrible hash function in order to generate many collisions.") \
1992 \
1993 product(bool, UseThreadsLockThrottleLock, true, DIAGNOSTIC, \
1994 "Use an extra lock during Thread start and exit to alleviate" \
1995 "contention on Threads_lock.") \
1996
1997 // end of RUNTIME_FLAGS
1998
1999 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2000 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2001 DECLARE_FLAGS(RUNTIME_FLAGS)
2002 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2003
2004 #endif // SHARE_RUNTIME_GLOBALS_HPP