1 /*
2 * Copyright (c) 1997, 2026, 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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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, UseCompactObjectHeaders, false, \
128 "Use compact 64-bit object headers in 64-bit VM") \
129 \
130 product(int, ObjectAlignmentInBytes, 8, \
131 "Default object alignment in bytes, 8 is minimum") \
132 range(8, 256) \
133 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
134
135 #else
136 // !_LP64
137
138 #define LP64_RUNTIME_FLAGS(develop, \
139 develop_pd, \
140 product, \
141 product_pd, \
142 range, \
143 constraint)
144 const bool UseCompressedOops = false;
145 const bool UseCompactObjectHeaders = false;
146 const int ObjectAlignmentInBytes = 8;
147
148 #endif // _LP64
149
150 #define RUNTIME_FLAGS(develop, \
151 develop_pd, \
152 product, \
153 product_pd, \
154 range, \
155 constraint) \
156 \
157 develop(bool, CheckCompressedOops, true, \
158 "Generate checks in encoding/decoding code in debug VM") \
159 \
160 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
161 "Heap allocation steps through preferred address regions to find" \
162 " where it can allocate the heap. Number of steps to take per " \
163 "region.") \
164 range(1, max_uintx) \
165 \
166 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
167 "If nonzero set a timeout in milliseconds for handshakes") \
168 \
169 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
170 "Force safe construction, as if all fields are final.") \
171 \
172 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
173 "Enable normal processing of flags relating to field diagnostics")\
174 \
175 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
176 "Enable normal processing of flags relating to experimental " \
177 "features") \
178 \
179 product(bool, JavaMonitorsInStackTrace, true, \
180 "Print information about Java monitor locks when the stacks are " \
181 "dumped") \
182 \
183 product_pd(bool, UseLargePages, \
184 "Use large page memory") \
185 \
186 product_pd(bool, UseLargePagesIndividualAllocation, \
187 "Allocate large pages individually for better affinity") \
188 \
189 develop(bool, LargePagesIndividualAllocationInjectError, false, \
190 "Fail large pages individual allocation") \
191 \
192 product(bool, UseNUMA, false, \
193 "Use NUMA if available") \
194 \
195 product(bool, UseNUMAInterleaving, false, \
196 "Interleave memory across NUMA nodes if available") \
197 \
198 product(size_t, NUMAInterleaveGranularity, 2*M, \
199 "Granularity to use for NUMA interleaving on Windows OS") \
200 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
201 \
202 product(bool, NUMAStats, false, \
203 "Print NUMA stats in detailed heap information") \
204 \
205 product(bool, UseAES, false, \
206 "Control whether AES instructions are used when available") \
207 \
208 product(bool, UseFMA, false, \
209 "Control whether FMA instructions are used when available") \
210 \
211 product(bool, UseSHA, false, \
212 "Control whether SHA instructions are used when available") \
213 \
214 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
215 "Use intrinsics for GHASH versions of crypto") \
216 \
217 product(bool, UseBASE64Intrinsics, false, \
218 "Use intrinsics for java.util.Base64") \
219 \
220 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
221 "Use intrinsics for sun.security.util.math.intpoly") \
222 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
223 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
224 \
225 product(size_t, LargePageSizeInBytes, 0, \
226 "Maximum large page size used (0 will use the default large " \
227 "page size for the environment as the maximum) " \
228 "(must be a power of 2)") \
229 range(0, max_uintx) \
230 constraint(LargePageSizeInBytesConstraintFunc, AtParse) \
231 \
232 product(size_t, LargePageHeapSizeThreshold, 128*M, \
233 "Use large pages if maximum heap is at least this big") \
234 range(0, max_uintx) \
235 \
236 product(bool, ForceTimeHighResolution, false, \
237 "Using high time resolution (for Win32 only)") \
238 \
239 develop(bool, TracePcPatching, false, \
240 "Trace usage of frame::patch_pc") \
241 \
242 develop(bool, TraceRelocator, false, \
243 "Trace the bytecode relocator") \
244 \
245 \
246 product(bool, SafepointALot, false, DIAGNOSTIC, \
247 "Generate a lot of safepoints. This works with " \
248 "GuaranteedSafepointInterval") \
249 \
250 product(bool, HandshakeALot, false, DIAGNOSTIC, \
251 "Generate a lot of handshakes. This works with " \
252 "GuaranteedSafepointInterval") \
253 \
254 product_pd(bool, BackgroundCompilation, \
255 "A thread requesting compilation is not blocked during " \
256 "compilation") \
257 \
258 product(bool, MethodFlushing, true, \
259 "Reclamation of compiled methods") \
260 \
261 develop(bool, VerifyStack, false, \
262 "Verify stack of each thread when it is entering a runtime call") \
263 \
264 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
265 "Make all non code cache addresses to be unreachable by " \
266 "forcing use of 64bit literal fixups") \
267 \
268 develop(bool, TraceDerivedPointers, false, \
269 "Trace traversal of derived pointers on stack") \
270 \
271 develop(bool, TraceCodeBlobStacks, false, \
272 "Trace stack-walk of codeblobs") \
273 \
274 develop(bool, PrintRewrites, false, \
275 "Print methods that are being rewritten") \
276 \
277 product(bool, UseInlineCaches, true, \
278 "Use Inline Caches for virtual calls ") \
279 \
280 develop(bool, VerifyInlineCaches, true, \
281 "Verify Inline Caches") \
282 \
283 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
284 "Inline arraycopy native that is known to be part of " \
285 "base library DLL") \
286 \
287 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
288 "Inline Object::hashCode() native that is known to be part " \
289 "of base library DLL") \
290 \
291 product(bool, InlineNatives, true, DIAGNOSTIC, \
292 "Inline natives that are known to be part of base library DLL") \
293 \
294 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
295 "Inline SinD, CosD, etc.") \
296 \
297 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
298 "Inline Class.isInstance, etc") \
299 \
300 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
301 "Inline Thread.currentThread, etc") \
302 \
303 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
304 "Inline memory ops (native methods) from Unsafe") \
305 \
306 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
307 "Use intrinsics for AES versions of crypto") \
308 \
309 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
310 "Use intrinsics for the paralleled version of AES/CTR crypto") \
311 \
312 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
313 "Use intrinsics for the vectorized version of ChaCha20") \
314 \
315 product(bool, UseKyberIntrinsics, false, DIAGNOSTIC, \
316 "Use intrinsics for the vectorized version of Kyber") \
317 \
318 product(bool, UseDilithiumIntrinsics, false, DIAGNOSTIC, \
319 "Use intrinsics for the vectorized version of Dilithium") \
320 \
321 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
322 "Use intrinsics for MD5 crypto hash function") \
323 \
324 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
325 "Use intrinsics for SHA-1 crypto hash function. " \
326 "Requires that UseSHA is enabled.") \
327 \
328 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
329 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
330 "Requires that UseSHA is enabled.") \
331 \
332 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
333 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
334 "Requires that UseSHA is enabled.") \
335 \
336 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
337 "Use intrinsics for SHA3 crypto hash function. " \
338 "Requires that UseSHA is enabled.") \
339 \
340 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
341 "use intrinsics for java.util.zip.CRC32") \
342 \
343 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
344 "use intrinsics for java.util.zip.CRC32C") \
345 \
346 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
347 "use intrinsics for java.util.zip.Adler32") \
348 \
349 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
350 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
351 \
352 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
353 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
354 \
355 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
356 "Enables intrinsification of Math.copySign") \
357 \
358 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
359 "Enables intrinsification of Math.signum") \
360 \
361 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
362 "Use Compiler thread for compiler's stubs generation") \
363 \
364 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
365 "do not expand intrinsics whose (internal) names appear here") \
366 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
367 \
368 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
369 "Control intrinsics using a list of +/- (internal) names, " \
370 "separated by commas") \
371 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
372 \
373 develop(bool, TraceCallFixup, false, \
374 "Trace all call fixups") \
375 \
376 develop(bool, DeoptimizeALot, false, \
377 "Deoptimize at every exit from the runtime system") \
378 \
379 develop(ccstrlist, DeoptimizeOnlyAt, "", \
380 "A comma separated list of bcis to deoptimize at") \
381 \
382 develop(bool, DeoptimizeRandom, false, \
383 "Deoptimize random frames on random exit from the runtime system")\
384 \
385 develop(bool, ZombieALot, false, \
386 "Create non-entrant nmethods at exit from the runtime system") \
387 \
388 develop(bool, WalkStackALot, false, \
389 "Trace stack (no print) at every exit from the runtime system") \
390 \
391 develop(bool, DeoptimizeObjectsALot, false, \
392 "For testing purposes concurrent threads revert optimizations " \
393 "based on escape analysis at intervals given with " \
394 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
395 "with DeoptimizeObjectsALotThreadCountSingle and " \
396 "DeoptimizeObjectsALotThreadCountAll.") \
397 \
398 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
399 "Interval for DeoptimizeObjectsALot.") \
400 range(0, max_jlong) \
401 \
402 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
403 "The number of threads that revert optimizations based on " \
404 "escape analysis for a single thread if DeoptimizeObjectsALot " \
405 "is enabled. The target thread is selected round robin." ) \
406 range(0, max_jint) \
407 \
408 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
409 "The number of threads that revert optimizations based on " \
410 "escape analysis for all threads if DeoptimizeObjectsALot " \
411 "is enabled." ) \
412 range(0, max_jint) \
413 \
414 develop(bool, VerifyLastFrame, false, \
415 "Verify oops on last frame on entry to VM") \
416 \
417 product(bool, SafepointTimeout, false, \
418 "Time out and warn or fail after SafepointTimeoutDelay " \
419 "milliseconds if failed to reach safepoint") \
420 \
421 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
422 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
423 \
424 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
425 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
426 range(0, max_jlong) \
427 \
428 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
429 "Abort upon failure to complete VM operation promptly") \
430 \
431 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
432 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
433 range(0, max_intx) \
434 \
435 product(bool, MaxFDLimit, true, \
436 "Bump the number of file descriptors to maximum (Unix only)") \
437 \
438 product(bool, LogEvents, true, DIAGNOSTIC, \
439 "Enable the various ring buffer event logs") \
440 \
441 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
442 "Number of ring buffer event logs") \
443 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
444 \
445 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
446 "Enable the Java bytecode verifier for remote classes") \
447 \
448 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
449 "Enable the Java bytecode verifier for local classes") \
450 \
451 develop(bool, VerifyStackAtCalls, false, \
452 "Verify that the stack pointer is unchanged after calls") \
453 \
454 develop(bool, TraceJavaAssertions, false, \
455 "Trace java language assertions") \
456 \
457 develop(bool, VerifyCodeCache, false, \
458 "Verify code cache on memory allocation/deallocation") \
459 \
460 develop(bool, ZapResourceArea, trueInDebug, \
461 "Zap freed resource/arena space") \
462 \
463 develop(bool, ZapVMHandleArea, trueInDebug, \
464 "Zap freed VM handle space") \
465 \
466 develop(bool, ZapStackSegments, trueInDebug, \
467 "Zap allocated/freed stack segments") \
468 \
469 develop(bool, ZapUnusedHeapArea, trueInDebug, \
470 "Zap unused heap space") \
471 \
472 develop(bool, ZapFillerObjects, trueInDebug, \
473 "Zap filler objects") \
474 \
475 develop(bool, ZapCHeap, trueInDebug, \
476 "Zap allocated/freed C heap space") \
477 \
478 develop(bool, ZapTLAB, trueInDebug, \
479 "Zap allocated TLABs") \
480 develop(bool, TestingAsyncLoggingDeathTest, false, \
481 "Recursive logging death test") \
482 develop(bool, TestingAsyncLoggingDeathTestNoCrash, false, \
483 "Recursive logging death test (no crash)") \
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, 18) \
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 develop(bool, VerifyAdapterSharing, false, \
609 "Verify that the code for shared adapters is the equivalent") \
610 \
611 product(bool, PrintAssembly, false, DIAGNOSTIC, \
612 "Print assembly code (using external disassembler.so)") \
613 \
614 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
615 "Print options string passed to disassembler.so") \
616 \
617 develop(bool, PrintNMethodStatistics, false, \
618 "Print a summary statistic for the generated nmethods") \
619 \
620 product(bool, PrintNMethods, false, DIAGNOSTIC, \
621 "Print assembly code for nmethods when generated") \
622 \
623 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
624 "Print assembly code for native nmethods when generated") \
625 \
626 develop(bool, PrintDebugInfo, false, \
627 "Print debug information for all nmethods when generated") \
628 \
629 develop(bool, PrintRelocations, false, \
630 "Print relocation information for all nmethods when generated") \
631 \
632 develop(bool, PrintDependencies, false, \
633 "Print dependency information for all nmethods when generated") \
634 \
635 develop(bool, PrintExceptionHandlers, false, \
636 "Print exception handler tables for all nmethods when generated") \
637 \
638 develop(bool, StressCompiledExceptionHandlers, false, \
639 "Exercise compiled exception handlers") \
640 \
641 product(bool, DeoptimizeOnAllocationException, false, DIAGNOSTIC, \
642 "Deoptimize on exception during allocation instead of using the " \
643 "compiled exception handlers") \
644 \
645 develop(bool, InterceptOSException, false, \
646 "Start debugger when an implicit OS (e.g. null pointer) " \
647 "exception happens") \
648 \
649 product(bool, PrintCodeCache, false, \
650 "Print the code cache memory usage when exiting") \
651 \
652 develop(bool, PrintCodeCache2, false, \
653 "Print detailed usage information on the code cache when exiting")\
654 \
655 product(bool, PrintCodeCacheOnCompilation, false, \
656 "Print the code cache memory usage each time a method is " \
657 "compiled") \
658 \
659 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
660 "Print code heap usage statistics on exit and on full condition") \
661 \
662 product(bool, PrintStubCode, false, DIAGNOSTIC, \
663 "Print generated stub code") \
664 \
665 product(bool, StackTraceInThrowable, true, \
666 "Collect backtrace in throwable when exception happens") \
667 \
668 product(bool, OmitStackTraceInFastThrow, true, \
669 "Omit backtraces for some 'hot' exceptions in optimized code") \
670 \
671 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
672 "Show exception messages from RuntimeExceptions that contain " \
673 "snippets of the failing code. Disable this to improve privacy.") \
674 \
675 product(bool, PrintWarnings, true, \
676 "Print JVM warnings to output stream") \
677 \
678 develop(bool, RegisterReferences, true, \
679 "Tell whether the VM should register soft/weak/final/phantom " \
680 "references") \
681 \
682 develop(bool, PrintCodeCacheExtension, false, \
683 "Print extension of code cache") \
684 \
685 product(bool, ClassUnloading, true, \
686 "Do unloading of classes") \
687 \
688 product(bool, ClassUnloadingWithConcurrentMark, true, \
689 "Do unloading of classes with a concurrent marking cycle") \
690 \
691 develop(bool, PrintSystemDictionaryAtExit, false, \
692 "Print the system dictionary at exit") \
693 \
694 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
695 "Print the class loader data graph at exit") \
696 \
697 product(bool, PrintVMInfoAtExit, false, DIAGNOSTIC, \
698 "Executes the VM.info diagnostic command at exit") \
699 \
700 product(bool, AllowParallelDefineClass, false, \
701 "Allow parallel defineClass requests for class loaders " \
702 "registering as parallel capable") \
703 \
704 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
705 "Disable the use of stack guard pages if the JVM is loaded " \
706 "on the primordial process thread") \
707 \
708 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
709 "Do JVMTI virtual thread mount/unmount transitions " \
710 "(disabling this flag implies no JVMTI events are posted)") \
711 \
712 /* notice: the max range value here is max_jint, not max_intx */ \
713 /* because of overflow issue */ \
714 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
715 "Async deflate idle monitors every so many milliseconds when " \
716 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
717 range(0, max_jint) \
718 \
719 /* notice: the max range value here is max_jint, not max_intx */ \
720 /* because of overflow issue */ \
721 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
722 "Async deflate idle monitors every so many milliseconds even " \
723 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
724 range(0, max_jint) \
725 \
726 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
727 "Used to estimate a variable ceiling based on number of threads " \
728 "for use with MonitorUsedDeflationThreshold (0 is off).") \
729 range(0, max_uintx) \
730 \
731 /* notice: the max range value here is max_jint, not max_intx */ \
732 /* because of overflow issue */ \
733 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
734 "The maximum number of monitors to deflate, unlink and delete " \
735 "at one time (minimum is 1024).") \
736 range(1024, max_jint) \
737 \
738 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
739 "The maximum number of monitors to unlink in one batch. ") \
740 range(1, max_jint) \
741 \
742 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
743 "Percentage of used monitors before triggering deflation (0 is " \
744 "off). The check is performed on AsyncDeflationInterval or " \
745 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
746 range(0, 100) \
747 \
748 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
749 "Max number of no progress async deflation attempts to tolerate " \
750 "before adjusting the in_use_list_ceiling up (0 is off).") \
751 range(0, max_uintx) \
752 \
753 product(intx, hashCode, 5, EXPERIMENTAL, \
754 "(Unstable) select hashCode generation algorithm") \
755 \
756 product(bool, ReduceSignalUsage, false, \
757 "Reduce the use of OS signals in Java and/or the VM") \
758 \
759 develop(bool, LoadLineNumberTables, true, \
760 "Tell whether the class file parser loads line number tables") \
761 \
762 develop(bool, LoadLocalVariableTables, true, \
763 "Tell whether the class file parser loads local variable tables") \
764 \
765 develop(bool, LoadLocalVariableTypeTables, true, \
766 "Tell whether the class file parser loads local variable type" \
767 "tables") \
768 \
769 product(bool, AllowUserSignalHandlers, false, \
770 "Application will install primary signal handlers for the JVM " \
771 "(Unix only)") \
772 \
773 product(bool, UseSignalChaining, true, \
774 "Use signal-chaining to invoke signal handlers installed " \
775 "by the application (Unix only)") \
776 \
777 product(bool, RestoreMXCSROnJNICalls, false, \
778 "Restore MXCSR when returning from JNI calls") \
779 \
780 product(bool, CheckJNICalls, false, \
781 "Verify all arguments to JNI calls") \
782 \
783 product(bool, UseFastJNIAccessors, true, \
784 "Use optimized versions of Get<Primitive>Field") \
785 \
786 product(intx, MaxJNILocalCapacity, 65536, \
787 "Maximum allowable local JNI handle capacity to " \
788 "EnsureLocalCapacity() and PushLocalFrame(), " \
789 "where <= 0 is unlimited, default: 65536") \
790 range(min_intx, max_intx) \
791 \
792 product(bool, EagerXrunInit, false, \
793 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
794 "but not all -Xrun libraries may support the state of the VM " \
795 "at this time") \
796 \
797 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
798 "Number of OutOfMemoryErrors preallocated with backtrace") \
799 range(0, 1024) \
800 \
801 develop(bool, PrintFieldLayout, false, \
802 "Print field layout for each class") \
803 \
804 /* Need to limit the extent of the padding to reasonable size. */\
805 /* 8K is well beyond the reasonable HW cache line size, even with */\
806 /* aggressive prefetching, while still leaving the room for segregating */\
807 /* among the distinct pages. */\
808 product(int, ContendedPaddingWidth, 128, \
809 "How many bytes to pad the fields/classes marked @Contended with")\
810 range(0, 8192) \
811 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
812 \
813 product(bool, EnableContended, true, \
814 "Enable @Contended annotation support") \
815 \
816 product(bool, RestrictContended, true, \
817 "Restrict @Contended to trusted classes") \
818 \
819 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
820 "Detect and take action upon identifying synchronization on " \
821 "value based classes. Modes: " \
822 "0: off; " \
823 "1: exit with fatal error; " \
824 "2: log message to stdout. Output file can be specified with " \
825 " -Xlog:valuebasedclasses. If JFR is running it will " \
826 " also generate JFR events.") \
827 range(0, 2) \
828 \
829 product(bool, ExitOnOutOfMemoryError, false, \
830 "JVM exits on the first occurrence of an out-of-memory error " \
831 "thrown from JVM") \
832 \
833 product(bool, CrashOnOutOfMemoryError, false, \
834 "JVM aborts, producing an error log and core/mini dump, on the " \
835 "first occurrence of an out-of-memory error thrown from JVM") \
836 \
837 product(intx, UserThreadWaitAttemptsAtExit, 30, \
838 "The number of times to wait for user threads to stop executing " \
839 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
840 "The maximum number of waits is 1000, to wait at most 10 " \
841 "seconds.") \
842 range(0, 1000) \
843 \
844 /* tracing */ \
845 \
846 develop(bool, StressRewriter, false, \
847 "Stress linktime bytecode rewriting") \
848 \
849 product(ccstr, TraceJVMTI, nullptr, \
850 "Trace flags for JVMTI functions and events") \
851 \
852 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
853 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
854 "This option can change an EMCP method into an obsolete method " \
855 "and can affect tests that expect specific methods to be EMCP. " \
856 "This option should be used with caution.") \
857 \
858 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
859 "(Deprecated) Allow redefinition to add and delete private " \
860 "static or final methods for compatibility with old releases") \
861 \
862 develop(bool, TraceBytecodes, false, \
863 "Trace bytecode execution") \
864 \
865 develop(bool, TraceBytecodesTruncated, false, \
866 "Truncate non control-flow bytecode when tracing bytecode") \
867 \
868 develop(bool, VerifyDependencies, trueInDebug, \
869 "Exercise and verify the compilation dependency mechanism") \
870 \
871 develop(bool, TimeOopMap, false, \
872 "Time calls to GenerateOopMap::compute_map() in sum") \
873 \
874 develop(bool, GenerateOopMapALot, false, \
875 "Generate interpreter oopmaps at all safepoints") \
876 \
877 develop(bool, TraceFinalizerRegistration, false, \
878 "Trace registration of final references") \
879 \
880 product(bool, IgnoreEmptyClassPaths, false, \
881 "Ignore empty path elements in -classpath") \
882 \
883 product(bool, PrintHeapAtSIGBREAK, true, \
884 "Print heap layout in response to SIGBREAK") \
885 \
886 product(bool, PrintClassHistogram, false, MANAGEABLE, \
887 "Print a histogram of class instances") \
888 \
889 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
890 "The percentage of the used heap that the instances of a class " \
891 "must occupy for the class to generate a trace event") \
892 range(0.0, 100.0) \
893 \
894 /* JVMTI heap profiling */ \
895 \
896 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
897 "Verify memory system before JVMTI iteration") \
898 \
899 /* compiler */ \
900 \
901 /* notice: the max range value here is max_jint, not max_intx */ \
902 /* because of overflow issue */ \
903 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
904 "Number of compiler threads to run") \
905 range(0, max_jint) \
906 constraint(CICompilerCountConstraintFunc, AfterErgo) \
907 \
908 product(bool, UseDynamicNumberOfCompilerThreads, true, \
909 "Dynamically choose the number of parallel compiler threads") \
910 \
911 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
912 "Reduce the number of parallel compiler threads when they " \
913 "are not used") \
914 \
915 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
916 "Trace creation and removal of compiler threads") \
917 \
918 product(ccstr, LogClassLoadingCauseFor, nullptr, \
919 "Apply -Xlog:class+load+cause* to classes whose fully " \
920 "qualified name contains this string (\"*\" matches " \
921 "any class).") \
922 \
923 develop(bool, InjectCompilerCreationFailure, false, \
924 "Inject thread creation failures for " \
925 "UseDynamicNumberOfCompilerThreads") \
926 \
927 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
928 "Generate code for implicit null checks") \
929 \
930 product_pd(bool, TrapBasedNullChecks, \
931 "Generate code for null checks that uses a cmp and trap " \
932 "instruction raising SIGTRAP. This is only used if an access to" \
933 "null (+offset) will not raise a SIGSEGV, i.e.," \
934 "ImplicitNullChecks don't work (PPC64).") \
935 \
936 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
937 "Enable Thread SMR Statistics") \
938 \
939 product(bool, Inline, true, \
940 "Enable inlining") \
941 \
942 product(bool, ClipInlining, true, \
943 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
944 \
945 develop(bool, UseCHA, true, \
946 "Enable CHA") \
947 \
948 product(bool, UseTypeProfile, true, \
949 "Check interpreter profile for historically monomorphic calls") \
950 \
951 product(bool, PrintInlining, false, DIAGNOSTIC, \
952 "Print inlining optimizations") \
953 \
954 product(bool, UsePopCountInstruction, false, \
955 "Use population count instruction") \
956 \
957 develop(bool, TraceMethodReplacement, false, \
958 "Print when methods are replaced do to recompilation") \
959 \
960 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
961 "Minimum number of sweeper passes before an nmethod " \
962 "can be flushed") \
963 range(0, max_intx) \
964 \
965 develop(bool, StressCodeBuffers, false, \
966 "Exercise code buffer expansion and other rare state changes") \
967 \
968 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
969 "Generate extra debugging information for non-safepoints in " \
970 "nmethods") \
971 \
972 product(bool, PrintVMOptions, false, \
973 "Print flags that appeared on the command line") \
974 \
975 product(bool, IgnoreUnrecognizedVMOptions, false, \
976 "Ignore unrecognized VM options") \
977 \
978 product(bool, PrintCommandLineFlags, false, \
979 "Print flags specified on command line or set by ergonomics") \
980 \
981 product(bool, PrintFlagsInitial, false, \
982 "Print all VM flags before argument processing and exit VM") \
983 \
984 product(bool, PrintFlagsFinal, false, \
985 "Print all VM flags after argument and ergonomic processing") \
986 \
987 develop(bool, PrintFlagsWithComments, false, \
988 "Print all VM flags with default values and descriptions and " \
989 "exit") \
990 \
991 product(bool, PrintFlagsRanges, false, \
992 "Print VM flags and their ranges") \
993 \
994 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
995 "Use a mutex to serialize output to tty and LogFile") \
996 \
997 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
998 "Display all VM output on the tty, independently of LogVMOutput") \
999 \
1000 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1001 "Save VM output to LogFile") \
1002 \
1003 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1004 "If LogVMOutput or LogCompilation is on, save VM output to " \
1005 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1006 \
1007 product(ccstr, ErrorFile, nullptr, \
1008 "If an error occurs, save the error data to this file " \
1009 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1010 \
1011 product(bool, ExtensiveErrorReports, \
1012 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1013 "Error reports are more extensive.") \
1014 \
1015 product(bool, DisplayVMOutputToStderr, false, \
1016 "If DisplayVMOutput is true, display all VM output to stderr") \
1017 \
1018 product(bool, DisplayVMOutputToStdout, false, \
1019 "If DisplayVMOutput is true, display all VM output to stdout") \
1020 \
1021 product(bool, ErrorFileToStderr, false, \
1022 "If true, error data is printed to stderr instead of a file") \
1023 \
1024 product(bool, ErrorFileToStdout, false, \
1025 "If true, error data is printed to stdout instead of a file") \
1026 \
1027 product(bool, PrintStringTableStatistics, false, \
1028 "print statistics about the StringTable and SymbolTable") \
1029 \
1030 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1031 "verify StringTable contents at exit") \
1032 \
1033 develop(bool, PrintSymbolTableSizeHistogram, false, \
1034 "print histogram of the symbol table") \
1035 \
1036 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1037 "Call fatal if this exception is thrown. Example: " \
1038 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1039 \
1040 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1041 "Call fatal if the exception pointed by AbortVMOnException " \
1042 "has this message") \
1043 \
1044 develop(bool, DebugVtables, false, \
1045 "add debugging code to vtable dispatch") \
1046 \
1047 product(bool, RangeCheckElimination, true, \
1048 "Eliminate range checks") \
1049 \
1050 develop_pd(bool, UncommonNullCast, \
1051 "track occurrences of null in casts; adjust compiler tactics") \
1052 \
1053 develop(bool, TypeProfileCasts, true, \
1054 "treat casts like calls for purposes of type profiling") \
1055 \
1056 develop(bool, TraceLivenessGen, false, \
1057 "Trace the generation of liveness analysis information") \
1058 \
1059 develop(bool, TraceLivenessQuery, false, \
1060 "Trace queries of liveness analysis information") \
1061 \
1062 develop(bool, CollectIndexSetStatistics, false, \
1063 "Collect information about IndexSets") \
1064 \
1065 /* This value is later shifted left by up to LogBytesPerLong bits */\
1066 /* (to convert from element count to size in bytes), so we must ensure */\
1067 /* it does not overflow during the shift. */\
1068 develop(int, FastAllocateSizeLimit, 128*K, \
1069 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1070 "Inline allocations larger than this in doublewords must go slow")\
1071 range(0, (1 << (BitsPerInt - LogBytesPerLong - 1)) - 1) \
1072 \
1073 product_pd(bool, CompactStrings, \
1074 "Enable Strings to use single byte chars in backing store") \
1075 \
1076 product_pd(uint, TypeProfileLevel, \
1077 "=XYZ, with Z: Type profiling of arguments at call; " \
1078 "Y: Type profiling of return value at call; " \
1079 "X: Type profiling of parameters to methods; " \
1080 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1081 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1082 \
1083 product(int, TypeProfileArgsLimit, 2, \
1084 "max number of call arguments to consider for type profiling") \
1085 range(0, 16) \
1086 \
1087 product(int, TypeProfileParmsLimit, 2, \
1088 "max number of incoming parameters to consider for type profiling"\
1089 ", -1 for all") \
1090 range(-1, 64) \
1091 \
1092 /* statistics */ \
1093 develop(bool, CountCompiledCalls, false, \
1094 "Count method invocations") \
1095 \
1096 develop(bool, ICMissHistogram, false, \
1097 "Produce histogram of IC misses") \
1098 \
1099 /* interpreter */ \
1100 product_pd(bool, RewriteBytecodes, \
1101 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1102 \
1103 product_pd(bool, RewriteFrequentPairs, \
1104 "Rewrite frequently used bytecode pairs into a single bytecode") \
1105 \
1106 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1107 "Print the generated interpreter code") \
1108 \
1109 product(bool, UseInterpreter, true, \
1110 "Use interpreter for non-compiled methods") \
1111 \
1112 develop(bool, UseFastSignatureHandlers, true, \
1113 "Use fast signature handlers for native calls") \
1114 \
1115 product(bool, UseLoopCounter, true, \
1116 "Increment invocation counter on backward branch") \
1117 \
1118 product_pd(bool, UseOnStackReplacement, \
1119 "Use on stack replacement, calls runtime if invoc. counter " \
1120 "overflows in loop") \
1121 \
1122 develop(bool, TraceOnStackReplacement, false, \
1123 "Trace on stack replacement") \
1124 \
1125 product_pd(bool, PreferInterpreterNativeStubs, \
1126 "Use always interpreter stubs for native methods invoked via " \
1127 "interpreter") \
1128 \
1129 develop(bool, CountBytecodes, false, \
1130 "Count number of bytecodes executed") \
1131 \
1132 develop(bool, PrintBytecodeHistogram, false, \
1133 "Print histogram of the executed bytecodes") \
1134 \
1135 develop(bool, PrintBytecodePairHistogram, false, \
1136 "Print histogram of the executed bytecode pairs") \
1137 \
1138 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1139 "Print code generated for native method signature handlers") \
1140 \
1141 develop(bool, VerifyOops, false, \
1142 "Do plausibility checks for oops") \
1143 \
1144 develop(bool, CheckUnhandledOops, false, \
1145 "Check for unhandled oops in VM code") \
1146 \
1147 develop(bool, VerifyJNIFields, trueInDebug, \
1148 "Verify jfieldIDs for instance fields") \
1149 \
1150 develop(bool, VerifyActivationFrameSize, false, \
1151 "Verify that activation frame didn't become smaller than its " \
1152 "minimal size") \
1153 \
1154 develop(bool, TraceFrequencyInlining, false, \
1155 "Trace frequency based inlining") \
1156 \
1157 develop_pd(bool, InlineIntrinsics, \
1158 "Use intrinsics in Interpreter that can be statically resolved") \
1159 \
1160 product_pd(bool, ProfileInterpreter, \
1161 "Profile at the bytecode level during interpretation") \
1162 \
1163 develop_pd(bool, ProfileTraps, \
1164 "Profile deoptimization traps at the bytecode level") \
1165 \
1166 product(intx, ProfileMaturityPercentage, 20, \
1167 "number of method invocations/branches (expressed as % of " \
1168 "CompileThreshold) before using the method's profile") \
1169 range(0, 100) \
1170 \
1171 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1172 "Print the results of +ProfileInterpreter at end of run") \
1173 \
1174 develop(bool, VerifyDataPointer, trueInDebug, \
1175 "Verify the method data pointer during interpreter profiling") \
1176 \
1177 develop(bool, CrashGCForDumpingJavaThread, false, \
1178 "Manually make GC thread crash then dump java stack trace; " \
1179 "Test only") \
1180 \
1181 /* compilation */ \
1182 product(bool, UseCompiler, true, \
1183 "Use Just-In-Time compilation") \
1184 \
1185 product(bool, AlwaysCompileLoopMethods, false, \
1186 "When using recompilation, never interpret methods " \
1187 "containing loops") \
1188 \
1189 product(int, AllocatePrefetchStyle, 1, \
1190 "0 = no prefetch, " \
1191 "1 = generate prefetch instructions for each allocation, " \
1192 "2 = use TLAB watermark to gate allocation prefetch, " \
1193 "3 = generate one prefetch instruction per cache line") \
1194 range(0, 3) \
1195 \
1196 product(int, AllocatePrefetchDistance, -1, \
1197 "Distance to prefetch ahead of allocation pointer. " \
1198 "-1: use system-specific value (automatically determined") \
1199 range(-1, 512) \
1200 \
1201 product(int, AllocatePrefetchLines, 3, \
1202 "Number of lines to prefetch ahead of array allocation pointer") \
1203 range(1, 64) \
1204 \
1205 product(int, AllocateInstancePrefetchLines, 1, \
1206 "Number of lines to prefetch ahead of instance allocation " \
1207 "pointer") \
1208 range(1, 64) \
1209 \
1210 product(int, AllocatePrefetchStepSize, 16, \
1211 "Step size in bytes of sequential prefetch instructions") \
1212 range(1, 512) \
1213 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1214 \
1215 product(intx, AllocatePrefetchInstr, 0, \
1216 "Select instruction to prefetch ahead of allocation pointer") \
1217 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1218 \
1219 /* deoptimization */ \
1220 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1221 "Trace deoptimization") \
1222 \
1223 develop(bool, PrintDeoptimizationDetails, false, \
1224 "Print more information about deoptimization") \
1225 \
1226 develop(bool, DebugDeoptimization, false, \
1227 "Tracing various information while debugging deoptimization") \
1228 \
1229 product(double, SelfDestructTimer, 0.0, \
1230 "Will cause VM to terminate after a given time " \
1231 "(in fractional minutes) " \
1232 "(0.0 means off)") \
1233 range(0.0, (double)max_intx) \
1234 \
1235 product(int, MaxJavaStackTraceDepth, 1024, \
1236 "The maximum number of lines in the stack trace for Java " \
1237 "exceptions (0 means all)") \
1238 range(0, max_jint/2) \
1239 \
1240 /* notice: the max range value here is max_jint, not max_intx */ \
1241 /* because of overflow issue */ \
1242 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1243 "Guarantee a safepoint (at least) every so many milliseconds " \
1244 "(0 means none)") \
1245 range(0, max_jint) \
1246 \
1247 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1248 "Wake the ServiceThread to do periodic cleanup checks every so " \
1249 "many milliseconds (0 means none)") \
1250 range(0, max_jint) \
1251 \
1252 product(double, SafepointTimeoutDelay, 10000, \
1253 "Delay in milliseconds for option SafepointTimeout; " \
1254 "supports sub-millisecond resolution with fractional values.") \
1255 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1256 \
1257 product(bool, UseSystemMemoryBarrier, false, \
1258 "Try to enable system memory barrier if supported by OS") \
1259 \
1260 product(intx, NmethodSweepActivity, 4, \
1261 "Removes cold nmethods from code cache if > 0. Higher values " \
1262 "result in more aggressive sweeping") \
1263 range(0, 2000) \
1264 \
1265 develop(intx, MallocCatchPtr, -1, \
1266 "Hit breakpoint when mallocing/freeing this pointer") \
1267 \
1268 develop(int, StackPrintLimit, 100, \
1269 "number of stack frames to print in VM-level stack dump") \
1270 \
1271 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1272 "max number of compiled code units to print in error log") \
1273 range(0, VMError::max_error_log_print_code) \
1274 \
1275 develop(int, MaxElementPrintSize, 256, \
1276 "maximum number of elements to print") \
1277 \
1278 develop(int, MaxStringPrintSize, 256, \
1279 "maximum number of characters to print for a java.lang.String " \
1280 "in the VM. If exceeded, an abridged version of the string is " \
1281 "printed with the middle of the string elided.") \
1282 range(2, O_BUFLEN) \
1283 \
1284 develop(intx, MaxSubklassPrintSize, 4, \
1285 "maximum number of subklasses to print when printing klass") \
1286 \
1287 develop(intx, MaxForceInlineLevel, 100, \
1288 "maximum number of nested calls that are forced for inlining " \
1289 "(using CompileCommand or marked w/ @ForceInline)") \
1290 range(0, max_jint) \
1291 \
1292 develop(intx, MethodHistogramCutoff, 100, \
1293 "The cutoff value for method invocation histogram (+CountCalls)") \
1294 \
1295 develop(intx, DeoptimizeALotInterval, 5, \
1296 "Number of exits until DeoptimizeALot kicks in") \
1297 \
1298 develop(intx, ZombieALotInterval, 5, \
1299 "Number of exits until ZombieALot kicks in") \
1300 \
1301 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1302 "Limit malloc allocation size from VM. Reaching a limit will " \
1303 "trigger an action (see flag). This feature requires " \
1304 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1305 "Usage:" \
1306 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1307 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1308 "sets one or more category-specific limits." \
1309 "<flag> defines the action upon reaching the limit:" \
1310 "\"fatal\": end VM with a fatal error at the allocation site" \
1311 "\"oom\" : will mimic a native OOM" \
1312 "If <flag> is omitted, \"fatal\" is the default." \
1313 "Examples:\n" \
1314 "-XX:MallocLimit=2g" \
1315 "-XX:MallocLimit=2g:oom" \
1316 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1317 \
1318 product(intx, TypeProfileWidth, 2, \
1319 "Number of receiver types to record in call/cast profile") \
1320 range(0, 8) \
1321 \
1322 develop(intx, BciProfileWidth, 2, \
1323 "Number of return bci's to record in ret profile") \
1324 \
1325 product(intx, PerMethodRecompilationCutoff, 400, \
1326 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1327 range(-1, max_intx) \
1328 \
1329 product(intx, PerBytecodeRecompilationCutoff, 200, \
1330 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1331 range(-1, max_intx) \
1332 \
1333 product(intx, PerMethodTrapLimit, 100, \
1334 "Limit on traps (of one kind) in a method (includes inlines)") \
1335 range(0, max_jint) \
1336 \
1337 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1338 "Limit on speculative traps (of one kind) in a method " \
1339 "(includes inlines)") \
1340 range(0, max_jint) \
1341 \
1342 product(intx, PerBytecodeTrapLimit, 4, \
1343 "Limit on traps (of one kind) at a particular BCI") \
1344 range(0, max_jint) \
1345 \
1346 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1347 "Extra method data trap entries for speculation") \
1348 range(0, 100) \
1349 \
1350 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1351 "Ratio of call site execution to caller method invocation") \
1352 \
1353 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1354 "Minimum ratio of call site execution to caller method" \
1355 "invocation to be considered for inlining") \
1356 \
1357 develop(intx, InlineThrowCount, 50, \
1358 "Force inlining of interpreted methods that throw this often") \
1359 range(0, max_jint) \
1360 \
1361 develop(intx, InlineThrowMaxSize, 200, \
1362 "Force inlining of throwing methods smaller than this") \
1363 range(0, max_jint) \
1364 \
1365 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1366 "Initial threshold (in bytes) at which a garbage collection " \
1367 "is done to reduce Metaspace usage") \
1368 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1369 \
1370 product(size_t, MaxMetaspaceSize, max_uintx, \
1371 "Maximum size of Metaspaces (in bytes)") \
1372 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1373 \
1374 product(size_t, CompressedClassSpaceSize, 1*G, \
1375 "Maximum size of class area in Metaspace when compressed " \
1376 "class pointers are used") \
1377 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1378 \
1379 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1380 "Force the class space to be allocated at this address or " \
1381 "fails VM initialization (requires -Xshare=off.") \
1382 \
1383 develop(bool, RandomizeClassSpaceLocation, true, \
1384 "Randomize location of class space.") \
1385 \
1386 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1387 "Print metaspace statistics upon VM exit.") \
1388 \
1389 product(bool, PrintCompilerMemoryStatisticsAtExit, false, DIAGNOSTIC, \
1390 "Print compiler memory statistics upon VM exit.") \
1391 \
1392 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1393 "The minimum percentage of heap free after GC to avoid expansion."\
1394 " For most GCs this applies to the old generation. In G1 and" \
1395 " ParallelGC it applies to the whole heap.") \
1396 range(0, 100) \
1397 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1398 \
1399 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1400 "The maximum percentage of heap free after GC to avoid shrinking."\
1401 " For most GCs this applies to the old generation. In G1 and" \
1402 " ParallelGC it applies to the whole heap.") \
1403 range(0, 100) \
1404 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1405 \
1406 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1407 "Number of milliseconds per MB of free space in the heap") \
1408 range(0, max_intx) \
1409 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1410 \
1411 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1412 "The minimum change in heap space due to GC (in bytes)") \
1413 range(0, max_uintx / 2 + 1) \
1414 \
1415 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1416 "The minimum expansion of Metaspace (in bytes)") \
1417 range(0, max_uintx) \
1418 \
1419 product(uint, MaxMetaspaceFreeRatio, 70, \
1420 "The maximum percentage of Metaspace free after GC to avoid " \
1421 "shrinking") \
1422 range(0, 100) \
1423 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1424 \
1425 product(uint, MinMetaspaceFreeRatio, 40, \
1426 "The minimum percentage of Metaspace free after GC to avoid " \
1427 "expansion") \
1428 range(0, 99) \
1429 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1430 \
1431 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1432 "The maximum expansion of Metaspace without full GC (in bytes)") \
1433 range(0, max_uintx) \
1434 \
1435 /* stack parameters */ \
1436 product_pd(intx, StackYellowPages, \
1437 "Number of yellow zone (recoverable overflows) pages of size " \
1438 "4KB. If pages are bigger yellow zone is aligned up.") \
1439 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1440 \
1441 product_pd(intx, StackRedPages, \
1442 "Number of red zone (unrecoverable overflows) pages of size " \
1443 "4KB. If pages are bigger red zone is aligned up.") \
1444 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1445 \
1446 product_pd(intx, StackReservedPages, \
1447 "Number of reserved zone (reserved to annotated methods) pages" \
1448 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1449 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1450 \
1451 product(bool, RestrictReservedStack, true, \
1452 "Restrict @ReservedStackAccess to trusted classes") \
1453 \
1454 /* greater stack shadow pages can't generate instruction to bang stack */ \
1455 product_pd(intx, StackShadowPages, \
1456 "Number of shadow zone (for overflow checking) pages of size " \
1457 "4KB. If pages are bigger shadow zone is aligned up. " \
1458 "This should exceed the depth of the VM and native call stack.") \
1459 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1460 \
1461 product_pd(intx, ThreadStackSize, \
1462 "Thread Stack Size (in Kbytes)") \
1463 range(0, 1 * M) \
1464 \
1465 product_pd(intx, VMThreadStackSize, \
1466 "Non-Java Thread Stack Size (in Kbytes)") \
1467 range(0, max_intx/(1 * K)) \
1468 \
1469 product_pd(intx, CompilerThreadStackSize, \
1470 "Compiler Thread Stack Size (in Kbytes)") \
1471 range(0, max_intx/(1 * K)) \
1472 \
1473 develop_pd(size_t, JVMInvokeMethodSlack, \
1474 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1475 \
1476 /* code cache parameters */ \
1477 product_pd(size_t, CodeCacheSegmentSize, EXPERIMENTAL, \
1478 "Code cache segment size (in bytes) - smallest unit of " \
1479 "allocation") \
1480 range(1, 1024) \
1481 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1482 \
1483 product_pd(uint, CodeEntryAlignment, EXPERIMENTAL, \
1484 "Code entry alignment for generated code" \
1485 " (in bytes, power of two)") \
1486 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1487 \
1488 product_pd(intx, OptoLoopAlignment, \
1489 "Align inner loops to zero relative to this modulus") \
1490 range(1, 128) \
1491 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1492 \
1493 product_pd(size_t, InitialCodeCacheSize, \
1494 "Initial code cache size (in bytes)") \
1495 constraint(VMPageSizeConstraintFunc, AtParse) \
1496 \
1497 develop_pd(size_t, CodeCacheMinimumUseSpace, \
1498 "Minimum code cache size (in bytes) required to start VM.") \
1499 range(0, SIZE_MAX) \
1500 \
1501 product(bool, SegmentedCodeCache, false, \
1502 "Use a segmented code cache") \
1503 \
1504 product_pd(size_t, ReservedCodeCacheSize, \
1505 "Reserved code cache size (in bytes) - maximum code cache size") \
1506 constraint(VMPageSizeConstraintFunc, AtParse) \
1507 \
1508 product_pd(size_t, NonProfiledCodeHeapSize, \
1509 "Size of code heap with non-profiled methods (in bytes)") \
1510 range(0, SIZE_MAX) \
1511 \
1512 product_pd(size_t, ProfiledCodeHeapSize, \
1513 "Size of code heap with profiled methods (in bytes)") \
1514 range(0, SIZE_MAX) \
1515 \
1516 product_pd(size_t, NonNMethodCodeHeapSize, \
1517 "Size of code heap with non-nmethods (in bytes)") \
1518 constraint(VMPageSizeConstraintFunc, AtParse) \
1519 \
1520 product(size_t, HotCodeHeapSize, 0, EXPERIMENTAL, \
1521 "Size of code heap with predicted hot methods (in bytes)") \
1522 range(0, SIZE_MAX) \
1523 \
1524 product_pd(size_t, CodeCacheExpansionSize, \
1525 "Code cache expansion size (in bytes)") \
1526 range(32*K, SIZE_MAX) \
1527 \
1528 product_pd(size_t, CodeCacheMinBlockLength, DIAGNOSTIC, \
1529 "Minimum number of segments in a code cache block") \
1530 range(1, 100) \
1531 \
1532 develop(bool, ExitOnFullCodeCache, false, \
1533 "Exit the VM if we fill the code cache") \
1534 \
1535 product(bool, UseCodeCacheFlushing, true, \
1536 "Remove cold/old nmethods from the code cache") \
1537 \
1538 product(double, SweeperThreshold, 15.0, \
1539 "Threshold when a code cache unloading GC is invoked." \
1540 "Value is percentage of ReservedCodeCacheSize.") \
1541 range(0.0, 100.0) \
1542 \
1543 product(uintx, StartAggressiveSweepingAt, 10, \
1544 "Start aggressive sweeping if less than X[%] of the total code cache is free.")\
1545 range(0, 100) \
1546 \
1547 product(bool, NMethodRelocation, false, EXPERIMENTAL, \
1548 "Enables use of experimental function nmethod::relocate()") \
1549 \
1550 /* interpreter debugging */ \
1551 develop(intx, BinarySwitchThreshold, 5, \
1552 "Minimal number of lookupswitch entries for rewriting to binary " \
1553 "switch") \
1554 \
1555 develop(uintx, StopInterpreterAt, 0, \
1556 "Stop interpreter execution at specified bytecode number") \
1557 \
1558 develop(uintx, TraceBytecodesAt, 0, \
1559 "Trace bytecodes starting with specified bytecode number") \
1560 \
1561 develop(uintx, TraceBytecodesStopAt, 0, \
1562 "Stop bytecode tracing at the specified bytecode number") \
1563 \
1564 /* Priorities */ \
1565 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1566 \
1567 product(int, ThreadPriorityPolicy, 0, \
1568 "0 : Normal. "\
1569 " VM chooses priorities that are appropriate for normal "\
1570 " applications. "\
1571 " On Windows applications are allowed to use higher native "\
1572 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1573 " not use the highest possible native priority, "\
1574 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1575 " system threads. On Linux thread priorities are ignored "\
1576 " because the OS does not support static priority in "\
1577 " SCHED_OTHER scheduling class which is the only choice for "\
1578 " non-root, non-realtime applications. "\
1579 "1 : Aggressive. "\
1580 " Java thread priorities map over to the entire range of "\
1581 " native thread priorities. Higher Java thread priorities map "\
1582 " to higher native thread priorities. This policy should be "\
1583 " used with care, as sometimes it can cause performance "\
1584 " degradation in the application and/or the entire system. On "\
1585 " Linux/BSD/macOS this policy requires root privilege or an "\
1586 " extended capability.") \
1587 range(0, 1) \
1588 \
1589 product(bool, ThreadPriorityVerbose, false, \
1590 "Print priority changes") \
1591 \
1592 product(int, CompilerThreadPriority, -1, \
1593 "The native priority at which compiler threads should run " \
1594 "(-1 means no change)") \
1595 range(min_jint, max_jint) \
1596 \
1597 product(int, VMThreadPriority, -1, \
1598 "The native priority at which the VM thread should run " \
1599 "(-1 means no change)") \
1600 range(min_jint, max_jint) \
1601 \
1602 product(int, JavaPriority1_To_OSPriority, -1, \
1603 "Map Java priorities to OS priorities") \
1604 range(min_jint, max_jint) \
1605 \
1606 product(int, JavaPriority2_To_OSPriority, -1, \
1607 "Map Java priorities to OS priorities") \
1608 range(min_jint, max_jint) \
1609 \
1610 product(int, JavaPriority3_To_OSPriority, -1, \
1611 "Map Java priorities to OS priorities") \
1612 range(min_jint, max_jint) \
1613 \
1614 product(int, JavaPriority4_To_OSPriority, -1, \
1615 "Map Java priorities to OS priorities") \
1616 range(min_jint, max_jint) \
1617 \
1618 product(int, JavaPriority5_To_OSPriority, -1, \
1619 "Map Java priorities to OS priorities") \
1620 range(min_jint, max_jint) \
1621 \
1622 product(int, JavaPriority6_To_OSPriority, -1, \
1623 "Map Java priorities to OS priorities") \
1624 range(min_jint, max_jint) \
1625 \
1626 product(int, JavaPriority7_To_OSPriority, -1, \
1627 "Map Java priorities to OS priorities") \
1628 range(min_jint, max_jint) \
1629 \
1630 product(int, JavaPriority8_To_OSPriority, -1, \
1631 "Map Java priorities to OS priorities") \
1632 range(min_jint, max_jint) \
1633 \
1634 product(int, JavaPriority9_To_OSPriority, -1, \
1635 "Map Java priorities to OS priorities") \
1636 range(min_jint, max_jint) \
1637 \
1638 product(int, JavaPriority10_To_OSPriority,-1, \
1639 "Map Java priorities to OS priorities") \
1640 range(min_jint, max_jint) \
1641 \
1642 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1643 "Java thread priority 10 maps to critical scheduling priority") \
1644 \
1645 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1646 "Compiler thread(s) run at critical scheduling priority") \
1647 \
1648 develop(intx, NewCodeParameter, 0, \
1649 "Testing Only: Create a dedicated integer parameter before " \
1650 "putback") \
1651 \
1652 /* new oopmap storage allocation */ \
1653 develop(int, MinOopMapAllocation, 8, \
1654 "Minimum number of OopMap entries in an OopMapSet") \
1655 range(0, max_jint) \
1656 \
1657 /* recompilation */ \
1658 product_pd(intx, CompileThreshold, \
1659 "number of interpreted method invocations before (re-)compiling") \
1660 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1661 \
1662 product_pd(bool, TieredCompilation, \
1663 "Enable tiered compilation") \
1664 \
1665 /* Properties for Java libraries */ \
1666 \
1667 product(uint64_t, MaxDirectMemorySize, 0, \
1668 "Maximum total size of NIO direct-buffer allocations. " \
1669 "Ignored if not explicitly set.") \
1670 range(0, max_jlong) \
1671 \
1672 /* Flags used for temporary code during development */ \
1673 \
1674 product(bool, UseNewCode, false, DIAGNOSTIC, \
1675 "Testing Only: Use the new version while testing") \
1676 \
1677 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1678 "Testing Only: Use the new version while testing") \
1679 \
1680 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1681 "Testing Only: Use the new version while testing") \
1682 \
1683 develop(bool, UseDebuggerErgo, false, \
1684 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1685 "Turns on the other UseDebuggerErgo* flags") \
1686 \
1687 develop(bool, UseDebuggerErgo1, false, \
1688 "Debugging Only: Enable workarounds for debugger induced " \
1689 "os::processor_id() >= os::processor_count() problems") \
1690 \
1691 develop(bool, UseDebuggerErgo2, false, \
1692 "Debugging Only: Limit the number of spawned JVM threads") \
1693 \
1694 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1695 "Enable JVMTI asserts related to stack depth checks") \
1696 \
1697 /* flags for performance data collection */ \
1698 \
1699 product(bool, UsePerfData, true, \
1700 "Flag to disable jvmstat instrumentation for performance testing "\
1701 "and problem isolation purposes") \
1702 \
1703 product(bool, PerfDataSaveToFile, false, \
1704 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1705 \
1706 product(ccstr, PerfDataSaveFile, nullptr, \
1707 "Save PerfData memory to the specified absolute pathname. " \
1708 "The string %p in the file name (if present) " \
1709 "will be replaced by pid") \
1710 \
1711 product(bool, PerfDisableSharedMem, false, \
1712 "Store performance data in standard memory") \
1713 \
1714 product(int, PerfDataMemorySize, 32*K, \
1715 "Size of performance data memory region. Will be rounded " \
1716 "up to a multiple of the native os page size.") \
1717 range(128, 32*64*K) \
1718 \
1719 product(int, PerfMaxStringConstLength, 1024, \
1720 "Maximum PerfStringConstant string length before truncation") \
1721 range(32, 32*K) \
1722 \
1723 product(bool, PerfAllowAtExitRegistration, false, \
1724 "Allow registration of atexit() methods") \
1725 \
1726 product(bool, PerfBypassFileSystemCheck, false, \
1727 "Bypass Win32 file system criteria checks (Windows Only)") \
1728 \
1729 product(int, UnguardOnExecutionViolation, 0, \
1730 "Unguard page and retry on no-execute fault (Win32 only) " \
1731 "0=off, 1=conservative, 2=aggressive") \
1732 range(0, 2) \
1733 \
1734 /* Serviceability Support */ \
1735 \
1736 product(bool, ManagementServer, false, \
1737 "Create JMX Management Server") \
1738 \
1739 product(bool, DisableAttachMechanism, false, \
1740 "Disable mechanism that allows tools to attach to this VM") \
1741 \
1742 product(bool, StartAttachListener, false, \
1743 "Always start Attach Listener at VM startup") \
1744 \
1745 product(bool, EnableDynamicAgentLoading, true, \
1746 "Allow tools to load agents with the attach mechanism") \
1747 \
1748 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1749 "Print java.util.concurrent locks in thread dump") \
1750 \
1751 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1752 "Print generated stub code for method handles") \
1753 \
1754 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1755 "perform extra checks when constructing method handles") \
1756 \
1757 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1758 "show method handle implementation frames (usually hidden)") \
1759 \
1760 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1761 "show virtual threads' carrier frames in exceptions") \
1762 \
1763 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1764 "trust final non-static declarations for constant folding") \
1765 \
1766 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1767 "Optimize loads from stable fields (marked w/ @Stable)") \
1768 \
1769 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1770 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1771 "resolved before the bootstrap method is called; 1: when a BSM " \
1772 "that may accept a BootstrapCallInfo is detected, use that API " \
1773 "to pass BSM arguments, which allows the BSM to delay their " \
1774 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1775 "via that API, instead of with the eagerly-resolved array.") \
1776 \
1777 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1778 "Causes the VM to pause at startup time and wait for the pause " \
1779 "file to be removed (default: ./vm.paused.<pid>)") \
1780 \
1781 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1782 "The file to create and for whose removal to await when pausing " \
1783 "at startup. (default: ./vm.paused.<pid>)") \
1784 \
1785 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1786 "Pause and wait for keypress on exit if a debugger is attached") \
1787 \
1788 product(bool, DTraceMethodProbes, false, \
1789 "Enable dtrace tool probes for method-entry and method-exit") \
1790 \
1791 product(bool, DTraceAllocProbes, false, \
1792 "Enable dtrace tool probes for object allocation") \
1793 \
1794 product(bool, DTraceMonitorProbes, false, \
1795 "Enable dtrace tool probes for monitor events") \
1796 \
1797 product(bool, RelaxAccessControlCheck, false, \
1798 "Relax the access control checks in the verifier") \
1799 \
1800 product(uintx, StringTableSize, defaultStringTableSize, \
1801 "Number of buckets in the interned String table " \
1802 "(will be rounded to nearest higher power of 2)") \
1803 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1804 \
1805 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1806 "Number of buckets in the JVM internal Symbol table") \
1807 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1808 \
1809 product(bool, UseStringDeduplication, false, \
1810 "Use string deduplication") \
1811 \
1812 product(uint, StringDeduplicationAgeThreshold, 3, \
1813 "A string must reach this age (or be promoted to an old region) " \
1814 "to be considered for deduplication") \
1815 range(1, markWord::max_age) \
1816 \
1817 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1818 "Approximate initial number of buckets in the table") \
1819 range(1, 1 * G) \
1820 \
1821 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1822 "Entries per bucket above which the table should be expanded") \
1823 range(0.1, 1000.0) \
1824 \
1825 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1826 "Entries per bucket below which the table should be shrunk") \
1827 range(0.01, 100.0) \
1828 \
1829 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1830 "Desired entries per bucket when resizing the table") \
1831 range(0.01, 1000.0) \
1832 \
1833 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1834 "Minimum number of dead table entries for cleaning the table") \
1835 \
1836 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1837 "Minimum percentage of dead table entries for cleaning the table") \
1838 range(1, 100) \
1839 \
1840 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1841 "Force more frequent table resizing") \
1842 \
1843 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1844 "Seed for the table hashing function; 0 requests computed seed") \
1845 \
1846 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1847 "Enable internal testing APIs") \
1848 \
1849 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1850 "Accesses to all variables should always be atomic") \
1851 \
1852 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1853 "Use unaligned memory accesses in Unsafe") \
1854 \
1855 product_pd(bool, PreserveFramePointer, \
1856 "Use the FP register for holding the frame pointer " \
1857 "and not as a general purpose register.") \
1858 \
1859 product(size_t, AsyncLogBufferSize, 2*M, \
1860 "Memory budget (in bytes) for the buffer of Asynchronous " \
1861 "Logging (-Xlog:async).") \
1862 range(DEBUG_ONLY(192) NOT_DEBUG(100*K), 50*M) \
1863 \
1864 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1865 "When a class C is loaded, check that " \
1866 "(1) all intrinsics defined by the VM for class C are present "\
1867 "in the loaded class file and are marked with the " \
1868 "@IntrinsicCandidate annotation, that " \
1869 "(2) there is an intrinsic registered for all loaded methods " \
1870 "that are annotated with the @IntrinsicCandidate annotation, " \
1871 "and that " \
1872 "(3) no orphan methods exist for class C (i.e., methods for " \
1873 "which the VM declares an intrinsic but that are not declared "\
1874 "in the loaded class C. " \
1875 "Check (3) is available only in debug builds.") \
1876 \
1877 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1878 "Threshold small size (in bytes) for clearing arrays. " \
1879 "Anything this size or smaller may get converted to discrete " \
1880 "scalar stores.") \
1881 range(0, max_intx) \
1882 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1883 \
1884 product(ccstr, AllocateHeapAt, nullptr, \
1885 "Path to the directory where a temporary file will be created " \
1886 "to use as the backing store for Java Heap.") \
1887 \
1888 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1889 "Enable VM continuations support") \
1890 \
1891 develop(bool, LoomDeoptAfterThaw, false, \
1892 "Deopt stack after thaw") \
1893 \
1894 develop(bool, LoomVerifyAfterThaw, false, \
1895 "Verify stack after thaw") \
1896 \
1897 develop(bool, VerifyContinuations, false, \
1898 "Verify continuation consistency") \
1899 \
1900 develop(bool, UseContinuationFastPath, true, \
1901 "Use fast-path frame walking in continuations") \
1902 \
1903 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1904 "Run periodic metaspace verifications (0 - none, " \
1905 "1 - always, >1 every nth interval)") \
1906 \
1907 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1908 "On internal errors, include registers in error report.") \
1909 \
1910 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1911 "leverage profiling for table/lookup switch") \
1912 \
1913 develop(bool, TraceMemoryWriteback, false, \
1914 "Trace memory writeback operations") \
1915 \
1916 JFR_ONLY(product(bool, FlightRecorder, false, \
1917 "(Deprecated) Enable Flight Recorder")) \
1918 \
1919 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1920 "Flight Recorder options")) \
1921 \
1922 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1923 "Start flight recording with options")) \
1924 \
1925 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1926 "Use platform unstable time where supported for timestamps only") \
1927 \
1928 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1929 "Make nmethod barriers deoptimise a lot.") \
1930 \
1931 develop(bool, VerifyCrossModifyFence, \
1932 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1933 "Mark all threads after a safepoint, and clear on a modify " \
1934 "fence. Add cleanliness checks.") \
1935 \
1936 product(bool, UseObjectMonitorTable, true, DIAGNOSTIC, \
1937 "Use a table to record inflated monitors rather than the first " \
1938 "word of the object.") \
1939 \
1940 product(int, FastLockingSpins, 13, DIAGNOSTIC, \
1941 "Specifies the number of times fast locking will attempt to " \
1942 "CAS the markWord before inflating. Between each CAS it will " \
1943 "spin for exponentially more time, resulting in a total number " \
1944 "of spins on the order of O(2^value)") \
1945 range(1, 30) \
1946 \
1947 product(uint, TrimNativeHeapInterval, 0, \
1948 "Interval, in ms, at which the JVM will trim the native heap if " \
1949 "the platform supports that. Lower values will reclaim memory " \
1950 "more eagerly at the cost of higher overhead. A value of 0 " \
1951 "(default) disables native heap trimming.") \
1952 range(0, UINT_MAX) \
1953 \
1954 develop(bool, SimulateFullAddressSpace, false, \
1955 "Simulates a very populated, fragmented address space; no " \
1956 "targeted reservations will succeed.") \
1957 \
1958 product(bool, ProfileExceptionHandlers, true, \
1959 "Profile exception handlers") \
1960 \
1961 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
1962 "Unconditionally record nmethod dependencies on class " \
1963 "rewriting/transformation independently of the JVMTI " \
1964 "can_{retransform/redefine}_classes capabilities.") \
1965 \
1966 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
1967 "Use secondary supers cache during subtype checks.") \
1968 \
1969 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
1970 "Use hash table to lookup secondary supers.") \
1971 \
1972 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
1973 "Check that linear and hashed secondary lookups return the same result.") \
1974 \
1975 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
1976 "Use a terrible hash function in order to generate many collisions.") \
1977 \
1978 product(bool, UseThreadsLockThrottleLock, true, DIAGNOSTIC, \
1979 "Use an extra lock during Thread start and exit to alleviate" \
1980 "contention on Threads_lock.") \
1981 \
1982 develop(uint, BinarySearchThreshold, 16, \
1983 "Minimal number of elements in a sorted collection to prefer" \
1984 "binary search over simple linear search." ) \
1985 \
1986
1987 // end of RUNTIME_FLAGS
1988
1989 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
1990 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
1991 DECLARE_FLAGS(RUNTIME_FLAGS)
1992 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
1993
1994 #endif // SHARE_RUNTIME_GLOBALS_HPP