1 /*
2 * Copyright (c) 1997, 2025, 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, 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 /* Leyden */ \
132 product(bool, UseCompatibleCompressedOops, false, \
133 "Always use HeapBasedNarrowOop mode, so that AOT code can be " \
134 "always work regardless of runtime heap range") \
135 \
136 product(bool, UseCompactObjectHeaders, false, EXPERIMENTAL, \
137 "Use compact 64-bit object headers in 64-bit VM") \
138 \
139 product(int, ObjectAlignmentInBytes, 8, \
140 "Default object alignment in bytes, 8 is minimum") \
141 range(8, 256) \
142 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
143
144 #else
145 // !_LP64
146
147 #define LP64_RUNTIME_FLAGS(develop, \
148 develop_pd, \
149 product, \
150 product_pd, \
151 range, \
152 constraint)
153 const bool UseCompressedOops = false;
154 const bool UseCompressedClassPointers = false;
155 const bool UseCompactObjectHeaders = false;
156 const int ObjectAlignmentInBytes = 8;
157
158 #endif // _LP64
159
160 #define RUNTIME_FLAGS(develop, \
161 develop_pd, \
162 product, \
163 product_pd, \
164 range, \
165 constraint) \
166 \
167 develop(bool, CheckCompressedOops, true, \
168 "Generate checks in encoding/decoding code in debug VM") \
169 \
170 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
171 "Heap allocation steps through preferred address regions to find" \
172 " where it can allocate the heap. Number of steps to take per " \
173 "region.") \
174 range(1, max_uintx) \
175 \
176 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
177 "If nonzero set a timeout in milliseconds for handshakes") \
178 \
179 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
180 "Force safe construction, as if all fields are final.") \
181 \
182 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
183 "Enable normal processing of flags relating to field diagnostics")\
184 \
185 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
186 "Enable normal processing of flags relating to experimental " \
187 "features") \
188 \
189 product(bool, JavaMonitorsInStackTrace, true, \
190 "Print information about Java monitor locks when the stacks are " \
191 "dumped") \
192 \
193 product_pd(bool, UseLargePages, \
194 "Use large page memory") \
195 \
196 product_pd(bool, UseLargePagesIndividualAllocation, \
197 "Allocate large pages individually for better affinity") \
198 \
199 develop(bool, LargePagesIndividualAllocationInjectError, false, \
200 "Fail large pages individual allocation") \
201 \
202 product(bool, UseNUMA, false, \
203 "Use NUMA if available") \
204 \
205 product(bool, UseNUMAInterleaving, false, \
206 "Interleave memory across NUMA nodes if available") \
207 \
208 product(size_t, NUMAInterleaveGranularity, 2*M, \
209 "Granularity to use for NUMA interleaving on Windows OS") \
210 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
211 \
212 product(uintx, NUMAChunkResizeWeight, 20, \
213 "Percentage (0-100) used to weight the current sample when " \
214 "computing exponentially decaying average for " \
215 "AdaptiveNUMAChunkSizing") \
216 range(0, 100) \
217 \
218 product(size_t, NUMASpaceResizeRate, 1*G, \
219 "Do not reallocate more than this amount per collection") \
220 range(0, max_uintx) \
221 \
222 product(bool, UseAdaptiveNUMAChunkSizing, true, \
223 "Enable adaptive chunk sizing for NUMA") \
224 \
225 product(bool, NUMAStats, false, \
226 "Print NUMA stats in detailed heap information") \
227 \
228 product(bool, UseAES, false, \
229 "Control whether AES instructions are used when available") \
230 \
231 product(bool, UseFMA, false, \
232 "Control whether FMA instructions are used when available") \
233 \
234 product(bool, UseSHA, false, \
235 "Control whether SHA instructions are used when available") \
236 \
237 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
238 "Use intrinsics for GHASH versions of crypto") \
239 \
240 product(bool, UseBASE64Intrinsics, false, \
241 "Use intrinsics for java.util.Base64") \
242 \
243 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
244 "Use intrinsics for sun.security.util.math.intpoly") \
245 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
246 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
247 \
248 product(size_t, LargePageSizeInBytes, 0, \
249 "Maximum large page size used (0 will use the default large " \
250 "page size for the environment as the maximum)") \
251 range(0, max_uintx) \
252 \
253 product(size_t, LargePageHeapSizeThreshold, 128*M, \
254 "Use large pages if maximum heap is at least this big") \
255 range(0, max_uintx) \
256 \
257 product(bool, ForceTimeHighResolution, false, \
258 "Using high time resolution (for Win32 only)") \
259 \
260 develop(bool, TracePcPatching, false, \
261 "Trace usage of frame::patch_pc") \
262 \
263 develop(bool, TraceRelocator, false, \
264 "Trace the bytecode relocator") \
265 \
266 \
267 product(bool, SafepointALot, false, DIAGNOSTIC, \
268 "Generate a lot of safepoints. This works with " \
269 "GuaranteedSafepointInterval") \
270 \
271 product(bool, HandshakeALot, false, DIAGNOSTIC, \
272 "Generate a lot of handshakes. This works with " \
273 "GuaranteedSafepointInterval") \
274 \
275 product_pd(bool, BackgroundCompilation, \
276 "A thread requesting compilation is not blocked during " \
277 "compilation") \
278 \
279 product(bool, MethodFlushing, true, \
280 "Reclamation of compiled methods") \
281 \
282 develop(bool, VerifyStack, false, \
283 "Verify stack of each thread when it is entering a runtime call") \
284 \
285 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
286 "Make all non code cache addresses to be unreachable by " \
287 "forcing use of 64bit literal fixups") \
288 \
289 develop(bool, TraceDerivedPointers, false, \
290 "Trace traversal of derived pointers on stack") \
291 \
292 develop(bool, TraceCodeBlobStacks, false, \
293 "Trace stack-walk of codeblobs") \
294 \
295 develop(bool, PrintRewrites, false, \
296 "Print methods that are being rewritten") \
297 \
298 product(bool, UseInlineCaches, true, \
299 "Use Inline Caches for virtual calls ") \
300 \
301 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
302 "Inline arraycopy native that is known to be part of " \
303 "base library DLL") \
304 \
305 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
306 "Inline Object::hashCode() native that is known to be part " \
307 "of base library DLL") \
308 \
309 product(bool, InlineNatives, true, DIAGNOSTIC, \
310 "Inline natives that are known to be part of base library DLL") \
311 \
312 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
313 "Inline SinD, CosD, etc.") \
314 \
315 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
316 "Inline Class.isInstance, etc") \
317 \
318 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
319 "Inline Thread.currentThread, etc") \
320 \
321 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
322 "Inline memory ops (native methods) from Unsafe") \
323 \
324 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
325 "Use intrinsics for AES versions of crypto") \
326 \
327 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
328 "Use intrinsics for the paralleled version of AES/CTR crypto") \
329 \
330 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
331 "Use intrinsics for the vectorized version of ChaCha20") \
332 \
333 product(bool, UseDilithiumIntrinsics, false, DIAGNOSTIC, \
334 "Use intrinsics for the vectorized version of Dilithium") \
335 \
336 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
337 "Use intrinsics for MD5 crypto hash function") \
338 \
339 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
340 "Use intrinsics for SHA-1 crypto hash function. " \
341 "Requires that UseSHA is enabled.") \
342 \
343 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
344 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
345 "Requires that UseSHA is enabled.") \
346 \
347 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
348 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
349 "Requires that UseSHA is enabled.") \
350 \
351 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
352 "Use intrinsics for SHA3 crypto hash function. " \
353 "Requires that UseSHA is enabled.") \
354 \
355 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
356 "use intrinsics for java.util.zip.CRC32") \
357 \
358 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
359 "use intrinsics for java.util.zip.CRC32C") \
360 \
361 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
362 "use intrinsics for java.util.zip.Adler32") \
363 \
364 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
365 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
366 \
367 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
368 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
369 \
370 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
371 "Enables intrinsification of Math.copySign") \
372 \
373 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
374 "Enables intrinsification of Math.signum") \
375 \
376 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
377 "Use Compiler thread for compiler's stubs generation") \
378 \
379 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
380 "do not expand intrinsics whose (internal) names appear here") \
381 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
382 \
383 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
384 "Control intrinsics using a list of +/- (internal) names, " \
385 "separated by commas") \
386 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
387 \
388 develop(ccstr, AddRuntimeUpcallsNOP, nullptr, \
389 "Register a runtime upcall for testing." \
390 "Format is '[upcallType]:[methodFilter]'" \
391 "where upcallType is one of 'onMethodEntry', 'onMethodExit'" \
392 "and methodFilter is one of 'none', 'all'") \
393 \
394 develop(bool, TraceCallFixup, false, \
395 "Trace all call fixups") \
396 \
397 develop(bool, DeoptimizeALot, false, \
398 "Deoptimize at every exit from the runtime system") \
399 \
400 develop(ccstrlist, DeoptimizeOnlyAt, "", \
401 "A comma separated list of bcis to deoptimize at") \
402 \
403 develop(bool, DeoptimizeRandom, false, \
404 "Deoptimize random frames on random exit from the runtime system")\
405 \
406 develop(bool, ZombieALot, false, \
407 "Create non-entrant nmethods at exit from the runtime system") \
408 \
409 develop(bool, WalkStackALot, false, \
410 "Trace stack (no print) at every exit from the runtime system") \
411 \
412 develop(bool, DeoptimizeObjectsALot, false, \
413 "For testing purposes concurrent threads revert optimizations " \
414 "based on escape analysis at intervals given with " \
415 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
416 "with DeoptimizeObjectsALotThreadCountSingle and " \
417 "DeoptimizeObjectsALotThreadCountAll.") \
418 \
419 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
420 "Interval for DeoptimizeObjectsALot.") \
421 range(0, max_jlong) \
422 \
423 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
424 "The number of threads that revert optimizations based on " \
425 "escape analysis for a single thread if DeoptimizeObjectsALot " \
426 "is enabled. The target thread is selected round robin." ) \
427 range(0, max_jint) \
428 \
429 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
430 "The number of threads that revert optimizations based on " \
431 "escape analysis for all threads if DeoptimizeObjectsALot " \
432 "is enabled." ) \
433 range(0, max_jint) \
434 \
435 develop(bool, VerifyLastFrame, false, \
436 "Verify oops on last frame on entry to VM") \
437 \
438 product(bool, SafepointTimeout, false, \
439 "Time out and warn or fail after SafepointTimeoutDelay " \
440 "milliseconds if failed to reach safepoint") \
441 \
442 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
443 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
444 \
445 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
446 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
447 range(0, max_jlong) \
448 \
449 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
450 "Abort upon failure to complete VM operation promptly") \
451 \
452 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
453 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
454 range(0, max_intx) \
455 \
456 product(bool, MaxFDLimit, true, \
457 "Bump the number of file descriptors to maximum (Unix only)") \
458 \
459 product(bool, LogEvents, true, DIAGNOSTIC, \
460 "Enable the various ring buffer event logs") \
461 \
462 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
463 "Number of ring buffer event logs") \
464 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
465 \
466 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
467 "Enable the Java bytecode verifier for remote classes") \
468 \
469 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
470 "Enable the Java bytecode verifier for local classes") \
471 \
472 develop(bool, VerifyStackAtCalls, false, \
473 "Verify that the stack pointer is unchanged after calls") \
474 \
475 develop(bool, TraceJavaAssertions, false, \
476 "Trace java language assertions") \
477 \
478 develop(bool, VerifyCodeCache, false, \
479 "Verify code cache on memory allocation/deallocation") \
480 \
481 develop(bool, ZapResourceArea, trueInDebug, \
482 "Zap freed resource/arena space") \
483 \
484 develop(bool, ZapVMHandleArea, trueInDebug, \
485 "Zap freed VM handle space") \
486 \
487 develop(bool, ZapStackSegments, trueInDebug, \
488 "Zap allocated/freed stack segments") \
489 \
490 develop(bool, ZapUnusedHeapArea, trueInDebug, \
491 "Zap unused heap space") \
492 \
493 develop(bool, ZapFillerObjects, trueInDebug, \
494 "Zap filler objects") \
495 \
496 develop(bool, ZapTLAB, trueInDebug, \
497 "Zap allocated TLABs") \
498 develop(bool, TestingAsyncLoggingDeathTest, false, \
499 "Recursive logging death test") \
500 develop(bool, TestingAsyncLoggingDeathTestNoCrash, false, \
501 "Recursive logging death test (no crash)") \
502 \
503 product(bool, ExecutingUnitTests, false, \
504 "Whether the JVM is running unit tests or not") \
505 \
506 develop(uint, ErrorHandlerTest, 0, \
507 "If > 0, provokes an error after VM initialization; the value " \
508 "determines which error to provoke. See controlled_crash() " \
509 "in vmError.cpp.") \
510 range(0, 17) \
511 \
512 develop(uint, TestCrashInErrorHandler, 0, \
513 "If > 0, provokes an error inside VM error handler (a secondary " \
514 "crash). see controlled_crash() in vmError.cpp") \
515 range(0, 17) \
516 \
517 develop(bool, TestSafeFetchInErrorHandler, false , \
518 "If true, tests SafeFetch inside error handler.") \
519 \
520 develop(bool, TestUnresponsiveErrorHandler, false, \
521 "If true, simulates an unresponsive error handler.") \
522 \
523 develop(bool, Verbose, false, \
524 "Print additional debugging information from other modes") \
525 \
526 develop(bool, PrintMiscellaneous, false, \
527 "Print uncategorized debugging information (requires +Verbose)") \
528 \
529 develop(bool, WizardMode, false, \
530 "Print much more debugging information") \
531 \
532 product(bool, ShowMessageBoxOnError, false, \
533 "Keep process alive on VM fatal error") \
534 \
535 product(bool, CreateCoredumpOnCrash, true, \
536 "Create core/mini dump on VM fatal error") \
537 \
538 product(uint64_t, ErrorLogTimeout, 2 * 60, \
539 "Timeout, in seconds, to limit the time spent on writing an " \
540 "error log in case of a crash.") \
541 range(0, (uint64_t)max_jlong/1000) \
542 \
543 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
544 "If enabled, show details on secondary crashes in the error log") \
545 \
546 develop(intx, TraceDwarfLevel, 0, \
547 "Debug levels for the dwarf parser") \
548 range(0, 4) \
549 \
550 product(bool, SuppressFatalErrorMessage, false, \
551 "Report NO fatal error message (avoid deadlock)") \
552 \
553 product(ccstrlist, OnError, "", \
554 "Run user-defined commands on fatal error; see VMError.cpp " \
555 "for examples") \
556 \
557 product(ccstrlist, OnOutOfMemoryError, "", \
558 "Run user-defined commands on first java.lang.OutOfMemoryError " \
559 "thrown from JVM") \
560 \
561 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
562 "Dump heap to file before any major stop-the-world GC " \
563 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
564 \
565 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
566 "Dump heap to file after any major stop-the-world GC " \
567 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
568 \
569 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
570 "Limit the number of heap dumps triggered by " \
571 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
572 "(0 means no limit)") \
573 \
574 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
575 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
576 "from JVM " \
577 "(also see HeapDumpPath, HeapDumpGzipLevel)") \
578 \
579 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
580 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
581 "or HeapDumpAfterFullGC is on, the path (filename or " \
582 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
583 "in the working directory)") \
584 \
585 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
586 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
587 "or HeapDumpAfterFullGC is on, the gzip compression " \
588 "level of the dump file. 0 (the default) disables gzip " \
589 "compression. Otherwise the level must be between 1 and 9.") \
590 range(0, 9) \
591 \
592 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
593 "Native memory tracking options") \
594 \
595 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
596 "Print native memory tracking summary data if it is on") \
597 \
598 product(bool, LogCompilation, false, DIAGNOSTIC, \
599 "Log compilation activity in detail to LogFile") \
600 \
601 product(bool, PrintCompilation, false, \
602 "Print compilations") \
603 \
604 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
605 "Repeat compilation without installing code (number of times)") \
606 range(0, max_jint) \
607 \
608 product(bool, PrintExtendedThreadInfo, false, \
609 "Print more information in thread dump") \
610 \
611 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
612 "0: do not allow scavengable oops in the code cache; " \
613 "1: allow scavenging from the code cache; " \
614 "2: emit as many constants as the compiler can see") \
615 range(0, 2) \
616 \
617 product(bool, AlwaysRestoreFPU, false, \
618 "Restore the FPU control word after every JNI call (expensive)") \
619 \
620 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
621 "Print additional statistics per compilation") \
622 \
623 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
624 "Print code generated for i2c/c2i adapters") \
625 \
626 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
627 "Verify that i2c/c2i adapters are called properly") \
628 \
629 develop(bool, VerifyAdapterSharing, false, \
630 "Verify that the code for shared adapters is the equivalent") \
631 \
632 product(bool, PrintAssembly, false, DIAGNOSTIC, \
633 "Print assembly code (using external disassembler.so)") \
634 \
635 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
636 "Print options string passed to disassembler.so") \
637 \
638 develop(bool, PrintNMethodStatistics, false, \
639 "Print a summary statistic for the generated nmethods") \
640 \
641 product(bool, PrintNMethods, false, DIAGNOSTIC, \
642 "Print assembly code for nmethods when generated") \
643 \
644 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
645 "Print assembly code for native nmethods when generated") \
646 \
647 develop(bool, PrintDebugInfo, false, \
648 "Print debug information for all nmethods when generated") \
649 \
650 develop(bool, PrintRelocations, false, \
651 "Print relocation information for all nmethods when generated") \
652 \
653 develop(bool, PrintDependencies, false, \
654 "Print dependency information for all nmethods when generated") \
655 \
656 develop(bool, PrintExceptionHandlers, false, \
657 "Print exception handler tables for all nmethods when generated") \
658 \
659 develop(bool, StressCompiledExceptionHandlers, false, \
660 "Exercise compiled exception handlers") \
661 \
662 develop(bool, InterceptOSException, false, \
663 "Start debugger when an implicit OS (e.g. null pointer) " \
664 "exception happens") \
665 \
666 product(bool, PrintCodeCache, false, \
667 "Print the code cache memory usage when exiting") \
668 \
669 develop(bool, PrintCodeCache2, false, \
670 "Print detailed usage information on the code cache when exiting")\
671 \
672 product(bool, PrintCodeCacheOnCompilation, false, \
673 "Print the code cache memory usage each time a method is " \
674 "compiled") \
675 \
676 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
677 "Print code heap usage statistics on exit and on full condition") \
678 \
679 product(bool, PrintStubCode, false, DIAGNOSTIC, \
680 "Print generated stub code") \
681 \
682 product(bool, StackTraceInThrowable, true, \
683 "Collect backtrace in throwable when exception happens") \
684 \
685 product(bool, OmitStackTraceInFastThrow, true, \
686 "Omit backtraces for some 'hot' exceptions in optimized code") \
687 \
688 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
689 "Show exception messages from RuntimeExceptions that contain " \
690 "snippets of the failing code. Disable this to improve privacy.") \
691 \
692 product(bool, PrintWarnings, true, \
693 "Print JVM warnings to output stream") \
694 \
695 develop(bool, RegisterReferences, true, \
696 "Tell whether the VM should register soft/weak/final/phantom " \
697 "references") \
698 \
699 develop(bool, PrintCodeCacheExtension, false, \
700 "Print extension of code cache") \
701 \
702 product(bool, ClassUnloading, true, \
703 "Do unloading of classes") \
704 \
705 product(bool, ClassUnloadingWithConcurrentMark, true, \
706 "Do unloading of classes with a concurrent marking cycle") \
707 \
708 develop(bool, PrintSystemDictionaryAtExit, false, \
709 "Print the system dictionary at exit") \
710 \
711 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
712 "Print the class loader data graph at exit") \
713 \
714 product(bool, AllowParallelDefineClass, false, \
715 "Allow parallel defineClass requests for class loaders " \
716 "registering as parallel capable") \
717 \
718 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
719 "Disable the use of stack guard pages if the JVM is loaded " \
720 "on the primordial process thread") \
721 \
722 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
723 "Do JVMTI virtual thread mount/unmount transitions " \
724 "(disabling this flag implies no JVMTI events are posted)") \
725 \
726 /* notice: the max range value here is max_jint, not max_intx */ \
727 /* because of overflow issue */ \
728 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
729 "Async deflate idle monitors every so many milliseconds when " \
730 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
731 range(0, max_jint) \
732 \
733 /* notice: the max range value here is max_jint, not max_intx */ \
734 /* because of overflow issue */ \
735 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
736 "Async deflate idle monitors every so many milliseconds even " \
737 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
738 range(0, max_jint) \
739 \
740 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
741 "Used to estimate a variable ceiling based on number of threads " \
742 "for use with MonitorUsedDeflationThreshold (0 is off).") \
743 range(0, max_uintx) \
744 \
745 /* notice: the max range value here is max_jint, not max_intx */ \
746 /* because of overflow issue */ \
747 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
748 "The maximum number of monitors to deflate, unlink and delete " \
749 "at one time (minimum is 1024).") \
750 range(1024, max_jint) \
751 \
752 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
753 "The maximum number of monitors to unlink in one batch. ") \
754 range(1, max_jint) \
755 \
756 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
757 "Percentage of used monitors before triggering deflation (0 is " \
758 "off). The check is performed on AsyncDeflationInterval or " \
759 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
760 range(0, 100) \
761 \
762 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
763 "Max number of no progress async deflation attempts to tolerate " \
764 "before adjusting the in_use_list_ceiling up (0 is off).") \
765 range(0, max_uintx) \
766 \
767 product(intx, hashCode, 5, EXPERIMENTAL, \
768 "(Unstable) select hashCode generation algorithm") \
769 \
770 product(bool, ReduceSignalUsage, false, \
771 "Reduce the use of OS signals in Java and/or the VM") \
772 \
773 develop(bool, LoadLineNumberTables, true, \
774 "Tell whether the class file parser loads line number tables") \
775 \
776 develop(bool, LoadLocalVariableTables, true, \
777 "Tell whether the class file parser loads local variable tables") \
778 \
779 develop(bool, LoadLocalVariableTypeTables, true, \
780 "Tell whether the class file parser loads local variable type" \
781 "tables") \
782 \
783 product(bool, AllowUserSignalHandlers, false, \
784 "Application will install primary signal handlers for the JVM " \
785 "(Unix only)") \
786 \
787 product(bool, UseSignalChaining, true, \
788 "Use signal-chaining to invoke signal handlers installed " \
789 "by the application (Unix only)") \
790 \
791 product(bool, RestoreMXCSROnJNICalls, false, \
792 "Restore MXCSR when returning from JNI calls") \
793 \
794 product(bool, CheckJNICalls, false, \
795 "Verify all arguments to JNI calls") \
796 \
797 product(bool, UseFastJNIAccessors, true, \
798 "Use optimized versions of Get<Primitive>Field") \
799 \
800 product(intx, MaxJNILocalCapacity, 65536, \
801 "Maximum allowable local JNI handle capacity to " \
802 "EnsureLocalCapacity() and PushLocalFrame(), " \
803 "where <= 0 is unlimited, default: 65536") \
804 range(min_intx, max_intx) \
805 \
806 product(bool, EagerXrunInit, false, \
807 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
808 "but not all -Xrun libraries may support the state of the VM " \
809 "at this time") \
810 \
811 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
812 "Number of OutOfMemoryErrors preallocated with backtrace") \
813 \
814 product(bool, UseXMMForArrayCopy, false, \
815 "Use SSE2 MOVQ instruction for Arraycopy") \
816 \
817 develop(bool, PrintFieldLayout, false, \
818 "Print field layout for each class") \
819 \
820 /* Need to limit the extent of the padding to reasonable size. */\
821 /* 8K is well beyond the reasonable HW cache line size, even with */\
822 /* aggressive prefetching, while still leaving the room for segregating */\
823 /* among the distinct pages. */\
824 product(int, ContendedPaddingWidth, 128, \
825 "How many bytes to pad the fields/classes marked @Contended with")\
826 range(0, 8192) \
827 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
828 \
829 product(bool, EnableContended, true, \
830 "Enable @Contended annotation support") \
831 \
832 product(bool, RestrictContended, true, \
833 "Restrict @Contended to trusted classes") \
834 \
835 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
836 "Detect and take action upon identifying synchronization on " \
837 "value based classes. Modes: " \
838 "0: off; " \
839 "1: exit with fatal error; " \
840 "2: log message to stdout. Output file can be specified with " \
841 " -Xlog:valuebasedclasses. If JFR is running it will " \
842 " also generate JFR events.") \
843 range(0, 2) \
844 \
845 product(bool, ExitOnOutOfMemoryError, false, \
846 "JVM exits on the first occurrence of an out-of-memory error " \
847 "thrown from JVM") \
848 \
849 product(bool, CrashOnOutOfMemoryError, false, \
850 "JVM aborts, producing an error log and core/mini dump, on the " \
851 "first occurrence of an out-of-memory error thrown from JVM") \
852 \
853 product(intx, UserThreadWaitAttemptsAtExit, 30, \
854 "The number of times to wait for user threads to stop executing " \
855 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
856 "The maximum number of waits is 1000, to wait at most 10 " \
857 "seconds.") \
858 range(0, 1000) \
859 \
860 /* tracing */ \
861 \
862 develop(bool, StressRewriter, false, \
863 "Stress linktime bytecode rewriting") \
864 \
865 product(ccstr, TraceJVMTI, nullptr, \
866 "Trace flags for JVMTI functions and events") \
867 \
868 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
869 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
870 "This option can change an EMCP method into an obsolete method " \
871 "and can affect tests that expect specific methods to be EMCP. " \
872 "This option should be used with caution.") \
873 \
874 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
875 "(Deprecated) Allow redefinition to add and delete private " \
876 "static or final methods for compatibility with old releases") \
877 \
878 develop(bool, TraceBytecodes, false, \
879 "Trace bytecode execution") \
880 \
881 develop(bool, TraceBytecodesTruncated, false, \
882 "Truncate non control-flow bytecode when tracing bytecode") \
883 \
884 develop(bool, VerifyDependencies, trueInDebug, \
885 "Exercise and verify the compilation dependency mechanism") \
886 \
887 develop(bool, TraceNewOopMapGeneration, false, \
888 "Trace OopMapGeneration") \
889 \
890 develop(bool, TraceNewOopMapGenerationDetailed, false, \
891 "Trace OopMapGeneration: print detailed cell states") \
892 \
893 develop(bool, TimeOopMap, false, \
894 "Time calls to GenerateOopMap::compute_map() in sum") \
895 \
896 develop(bool, TimeOopMap2, false, \
897 "Time calls to GenerateOopMap::compute_map() individually") \
898 \
899 develop(bool, TraceOopMapRewrites, false, \
900 "Trace rewriting of methods during oop map generation") \
901 \
902 develop(bool, TraceFinalizerRegistration, false, \
903 "Trace registration of final references") \
904 \
905 product(bool, IgnoreEmptyClassPaths, false, \
906 "Ignore empty path elements in -classpath") \
907 \
908 product(bool, PrintHeapAtSIGBREAK, true, \
909 "Print heap layout in response to SIGBREAK") \
910 \
911 product(bool, PrintClassHistogram, false, MANAGEABLE, \
912 "Print a histogram of class instances") \
913 \
914 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
915 "The percentage of the used heap that the instances of a class " \
916 "must occupy for the class to generate a trace event") \
917 range(0.0, 100.0) \
918 \
919 /* JVMTI heap profiling */ \
920 \
921 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
922 "Verify memory system before JVMTI iteration") \
923 \
924 /* compiler */ \
925 \
926 /* notice: the max range value here is max_jint, not max_intx */ \
927 /* because of overflow issue */ \
928 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
929 "Number of compiler threads to run") \
930 range(0, max_jint) \
931 constraint(CICompilerCountConstraintFunc, AfterErgo) \
932 \
933 product(bool, UseDynamicNumberOfCompilerThreads, true, \
934 "Dynamically choose the number of parallel compiler threads") \
935 \
936 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
937 "Reduce the number of parallel compiler threads when they " \
938 "are not used") \
939 \
940 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
941 "Trace creation and removal of compiler threads") \
942 \
943 product(ccstr, LogClassLoadingCauseFor, nullptr, \
944 "Apply -Xlog:class+load+cause* to classes whose fully " \
945 "qualified name contains this string (\"*\" matches " \
946 "any class).") \
947 \
948 develop(bool, InjectCompilerCreationFailure, false, \
949 "Inject thread creation failures for " \
950 "UseDynamicNumberOfCompilerThreads") \
951 \
952 develop(bool, GenerateSynchronizationCode, true, \
953 "generate locking/unlocking code for synchronized methods and " \
954 "monitors") \
955 \
956 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
957 "Generate code for implicit null checks") \
958 \
959 product_pd(bool, TrapBasedNullChecks, \
960 "Generate code for null checks that uses a cmp and trap " \
961 "instruction raising SIGTRAP. This is only used if an access to" \
962 "null (+offset) will not raise a SIGSEGV, i.e.," \
963 "ImplicitNullChecks don't work (PPC64).") \
964 \
965 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
966 "Enable Thread SMR Statistics") \
967 \
968 product(bool, Inline, true, \
969 "Enable inlining") \
970 \
971 product(bool, ClipInlining, true, \
972 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
973 \
974 develop(bool, UseCHA, true, \
975 "Enable CHA") \
976 \
977 product(bool, UseTypeProfile, true, \
978 "Check interpreter profile for historically monomorphic calls") \
979 \
980 product(bool, PrintInlining, false, DIAGNOSTIC, \
981 "Print inlining optimizations") \
982 \
983 product(bool, UsePopCountInstruction, false, \
984 "Use population count instruction") \
985 \
986 develop(bool, TraceMethodReplacement, false, \
987 "Print when methods are replaced do to recompilation") \
988 \
989 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
990 "Minimum number of sweeper passes before an nmethod " \
991 "can be flushed") \
992 range(0, max_intx) \
993 \
994 develop(bool, StressCodeBuffers, false, \
995 "Exercise code buffer expansion and other rare state changes") \
996 \
997 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
998 "Generate extra debugging information for non-safepoints in " \
999 "nmethods") \
1000 \
1001 product(bool, PrintVMOptions, false, \
1002 "Print flags that appeared on the command line") \
1003 \
1004 product(bool, IgnoreUnrecognizedVMOptions, false, \
1005 "Ignore unrecognized VM options") \
1006 \
1007 product(bool, PrintCommandLineFlags, false, \
1008 "Print flags specified on command line or set by ergonomics") \
1009 \
1010 product(bool, PrintFlagsInitial, false, \
1011 "Print all VM flags before argument processing and exit VM") \
1012 \
1013 product(bool, PrintFlagsFinal, false, \
1014 "Print all VM flags after argument and ergonomic processing") \
1015 \
1016 develop(bool, PrintFlagsWithComments, false, \
1017 "Print all VM flags with default values and descriptions and " \
1018 "exit") \
1019 \
1020 product(bool, PrintFlagsRanges, false, \
1021 "Print VM flags and their ranges") \
1022 \
1023 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1024 "Use a mutex to serialize output to tty and LogFile") \
1025 \
1026 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1027 "Display all VM output on the tty, independently of LogVMOutput") \
1028 \
1029 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1030 "Save VM output to LogFile") \
1031 \
1032 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1033 "If LogVMOutput or LogCompilation is on, save VM output to " \
1034 "this file [default: ./hotspot_%p.log] (%p replaced with pidNNN)")\
1035 \
1036 product(ccstr, ErrorFile, nullptr, \
1037 "If an error occurs, save the error data to this file " \
1038 "[default: ./hs_err_%p.log] (%p replaced with pidNNN)") \
1039 \
1040 product(bool, ExtensiveErrorReports, \
1041 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1042 "Error reports are more extensive.") \
1043 \
1044 product(bool, DisplayVMOutputToStderr, false, \
1045 "If DisplayVMOutput is true, display all VM output to stderr") \
1046 \
1047 product(bool, DisplayVMOutputToStdout, false, \
1048 "If DisplayVMOutput is true, display all VM output to stdout") \
1049 \
1050 product(bool, ErrorFileToStderr, false, \
1051 "If true, error data is printed to stderr instead of a file") \
1052 \
1053 product(bool, ErrorFileToStdout, false, \
1054 "If true, error data is printed to stdout instead of a file") \
1055 \
1056 develop(bool, VerifyHeavyMonitors, false, \
1057 "Checks that no stack locking happens when using " \
1058 "-XX:LockingMode=0 (LM_MONITOR)") \
1059 \
1060 product(bool, PrintStringTableStatistics, false, \
1061 "print statistics about the StringTable and SymbolTable") \
1062 \
1063 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1064 "verify StringTable contents at exit") \
1065 \
1066 develop(bool, PrintSymbolTableSizeHistogram, false, \
1067 "print histogram of the symbol table") \
1068 \
1069 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1070 "Call fatal if this exception is thrown. Example: " \
1071 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1072 \
1073 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1074 "Call fatal if the exception pointed by AbortVMOnException " \
1075 "has this message") \
1076 \
1077 develop(bool, DebugVtables, false, \
1078 "add debugging code to vtable dispatch") \
1079 \
1080 product(bool, RangeCheckElimination, true, \
1081 "Eliminate range checks") \
1082 \
1083 develop_pd(bool, UncommonNullCast, \
1084 "track occurrences of null in casts; adjust compiler tactics") \
1085 \
1086 develop(bool, TypeProfileCasts, true, \
1087 "treat casts like calls for purposes of type profiling") \
1088 \
1089 develop(bool, TraceLivenessGen, false, \
1090 "Trace the generation of liveness analysis information") \
1091 \
1092 develop(bool, TraceLivenessQuery, false, \
1093 "Trace queries of liveness analysis information") \
1094 \
1095 develop(bool, CollectIndexSetStatistics, false, \
1096 "Collect information about IndexSets") \
1097 \
1098 develop(int, FastAllocateSizeLimit, 128*K, \
1099 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1100 "Inline allocations larger than this in doublewords must go slow")\
1101 \
1102 product_pd(bool, CompactStrings, \
1103 "Enable Strings to use single byte chars in backing store") \
1104 \
1105 product_pd(uint, TypeProfileLevel, \
1106 "=XYZ, with Z: Type profiling of arguments at call; " \
1107 "Y: Type profiling of return value at call; " \
1108 "X: Type profiling of parameters to methods; " \
1109 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1110 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1111 \
1112 product(int, TypeProfileArgsLimit, 2, \
1113 "max number of call arguments to consider for type profiling") \
1114 range(0, 16) \
1115 \
1116 product(int, TypeProfileParmsLimit, 2, \
1117 "max number of incoming parameters to consider for type profiling"\
1118 ", -1 for all") \
1119 range(-1, 64) \
1120 \
1121 /* statistics */ \
1122 develop(bool, CountCompiledCalls, false, \
1123 "Count method invocations") \
1124 \
1125 develop(bool, ICMissHistogram, false, \
1126 "Produce histogram of IC misses") \
1127 \
1128 /* interpreter */ \
1129 product_pd(bool, RewriteBytecodes, \
1130 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1131 \
1132 product_pd(bool, RewriteFrequentPairs, \
1133 "Rewrite frequently used bytecode pairs into a single bytecode") \
1134 \
1135 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1136 "Print the generated interpreter code") \
1137 \
1138 product(bool, UseInterpreter, true, \
1139 "Use interpreter for non-compiled methods") \
1140 \
1141 develop(bool, UseFastSignatureHandlers, true, \
1142 "Use fast signature handlers for native calls") \
1143 \
1144 product(bool, UseLoopCounter, true, \
1145 "Increment invocation counter on backward branch") \
1146 \
1147 product_pd(bool, UseOnStackReplacement, \
1148 "Use on stack replacement, calls runtime if invoc. counter " \
1149 "overflows in loop") \
1150 \
1151 develop(bool, TraceOnStackReplacement, false, \
1152 "Trace on stack replacement") \
1153 \
1154 product_pd(bool, PreferInterpreterNativeStubs, \
1155 "Use always interpreter stubs for native methods invoked via " \
1156 "interpreter") \
1157 \
1158 product(bool, CountBytecodes, false, DIAGNOSTIC, \
1159 "Count number of bytecodes executed") \
1160 \
1161 product(bool, CountBytecodesPerThread, false, DIAGNOSTIC, \
1162 "Count number of bytecodes executed per thread") \
1163 \
1164 product(bool, PrintBytecodeHistogram, false, DIAGNOSTIC, \
1165 "Print histogram of the executed bytecodes") \
1166 \
1167 product(double, PrintBytecodeHistogramCutoff, 0.01, \
1168 "Print cutoff for histogram of the executed bytecodes") \
1169 range(0.0, 100.0) \
1170 \
1171 develop(bool, PrintBytecodePairHistogram, false, \
1172 "Print histogram of the executed bytecode pairs") \
1173 \
1174 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1175 "Print code generated for native method signature handlers") \
1176 \
1177 develop(bool, VerifyOops, false, \
1178 "Do plausibility checks for oops") \
1179 \
1180 develop(bool, CheckUnhandledOops, false, \
1181 "Check for unhandled oops in VM code") \
1182 \
1183 develop(bool, VerifyJNIFields, trueInDebug, \
1184 "Verify jfieldIDs for instance fields") \
1185 \
1186 develop(bool, VerifyFPU, false, \
1187 "Verify FPU state (check for NaN's, etc.)") \
1188 \
1189 develop(bool, VerifyActivationFrameSize, false, \
1190 "Verify that activation frame didn't become smaller than its " \
1191 "minimal size") \
1192 \
1193 develop(bool, TraceFrequencyInlining, false, \
1194 "Trace frequency based inlining") \
1195 \
1196 develop_pd(bool, InlineIntrinsics, \
1197 "Use intrinsics in Interpreter that can be statically resolved") \
1198 \
1199 product_pd(bool, ProfileInterpreter, \
1200 "Profile at the bytecode level during interpretation") \
1201 \
1202 develop_pd(bool, ProfileTraps, \
1203 "Profile deoptimization traps at the bytecode level") \
1204 \
1205 product(intx, ProfileMaturityPercentage, 20, \
1206 "number of method invocations/branches (expressed as % of " \
1207 "CompileThreshold) before using the method's profile") \
1208 range(0, 100) \
1209 \
1210 product(bool, ForceProfiling, false, DIAGNOSTIC, \
1211 "Eagerly allocate MDOs") \
1212 \
1213 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1214 "Print the results of +ProfileInterpreter at end of run") \
1215 \
1216 develop(bool, VerifyDataPointer, trueInDebug, \
1217 "Verify the method data pointer during interpreter profiling") \
1218 \
1219 develop(bool, CrashGCForDumpingJavaThread, false, \
1220 "Manually make GC thread crash then dump java stack trace; " \
1221 "Test only") \
1222 \
1223 /* compilation */ \
1224 product(bool, UseCompiler, true, \
1225 "Use Just-In-Time compilation") \
1226 \
1227 product(bool, AlwaysCompileLoopMethods, false, \
1228 "When using recompilation, never interpret methods " \
1229 "containing loops") \
1230 \
1231 product(int, AllocatePrefetchStyle, 1, \
1232 "0 = no prefetch, " \
1233 "1 = generate prefetch instructions for each allocation, " \
1234 "2 = use TLAB watermark to gate allocation prefetch, " \
1235 "3 = generate one prefetch instruction per cache line") \
1236 range(0, 3) \
1237 \
1238 product(int, AllocatePrefetchDistance, -1, \
1239 "Distance to prefetch ahead of allocation pointer. " \
1240 "-1: use system-specific value (automatically determined") \
1241 range(-1, 512) \
1242 \
1243 product(int, AllocatePrefetchLines, 3, \
1244 "Number of lines to prefetch ahead of array allocation pointer") \
1245 range(1, 64) \
1246 \
1247 product(int, AllocateInstancePrefetchLines, 1, \
1248 "Number of lines to prefetch ahead of instance allocation " \
1249 "pointer") \
1250 range(1, 64) \
1251 \
1252 product(int, AllocatePrefetchStepSize, 16, \
1253 "Step size in bytes of sequential prefetch instructions") \
1254 range(1, 512) \
1255 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1256 \
1257 product(intx, AllocatePrefetchInstr, 0, \
1258 "Select instruction to prefetch ahead of allocation pointer") \
1259 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1260 \
1261 /* deoptimization */ \
1262 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1263 "Trace deoptimization") \
1264 \
1265 develop(bool, PrintDeoptimizationDetails, false, \
1266 "Print more information about deoptimization") \
1267 \
1268 develop(bool, DebugDeoptimization, false, \
1269 "Tracing various information while debugging deoptimization") \
1270 \
1271 product(double, SelfDestructTimer, 0.0, \
1272 "Will cause VM to terminate after a given time " \
1273 "(in fractional minutes) " \
1274 "(0.0 means off)") \
1275 range(0.0, (double)max_intx) \
1276 \
1277 product(int, MaxJavaStackTraceDepth, 1024, \
1278 "The maximum number of lines in the stack trace for Java " \
1279 "exceptions (0 means all)") \
1280 range(0, max_jint/2) \
1281 \
1282 /* notice: the max range value here is max_jint, not max_intx */ \
1283 /* because of overflow issue */ \
1284 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1285 "Guarantee a safepoint (at least) every so many milliseconds " \
1286 "(0 means none)") \
1287 range(0, max_jint) \
1288 \
1289 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1290 "Wake the ServiceThread to do periodic cleanup checks every so " \
1291 "many milliseconds (0 means none)") \
1292 range(0, max_jint) \
1293 \
1294 product(double, SafepointTimeoutDelay, 10000, \
1295 "Delay in milliseconds for option SafepointTimeout; " \
1296 "supports sub-millisecond resolution with fractional values.") \
1297 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1298 \
1299 product(bool, UseSystemMemoryBarrier, false, \
1300 "Try to enable system memory barrier if supported by OS") \
1301 \
1302 product(intx, NmethodSweepActivity, 4, \
1303 "Removes cold nmethods from code cache if > 0. Higher values " \
1304 "result in more aggressive sweeping") \
1305 range(0, 2000) \
1306 \
1307 develop(intx, MallocCatchPtr, -1, \
1308 "Hit breakpoint when mallocing/freeing this pointer") \
1309 \
1310 develop(int, StackPrintLimit, 100, \
1311 "number of stack frames to print in VM-level stack dump") \
1312 \
1313 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1314 "max number of compiled code units to print in error log") \
1315 range(0, VMError::max_error_log_print_code) \
1316 \
1317 develop(int, MaxElementPrintSize, 256, \
1318 "maximum number of elements to print") \
1319 \
1320 develop(int, MaxStringPrintSize, 256, \
1321 "maximum number of characters to print for a java.lang.String " \
1322 "in the VM. If exceeded, an abridged version of the string is " \
1323 "printed with the middle of the string elided.") \
1324 range(2, O_BUFLEN) \
1325 \
1326 develop(intx, MaxSubklassPrintSize, 4, \
1327 "maximum number of subklasses to print when printing klass") \
1328 \
1329 develop(intx, MaxForceInlineLevel, 100, \
1330 "maximum number of nested calls that are forced for inlining " \
1331 "(using CompileCommand or marked w/ @ForceInline)") \
1332 range(0, max_jint) \
1333 \
1334 develop(intx, MethodHistogramCutoff, 100, \
1335 "The cutoff value for method invocation histogram (+CountCalls)") \
1336 \
1337 develop(intx, DeoptimizeALotInterval, 5, \
1338 "Number of exits until DeoptimizeALot kicks in") \
1339 \
1340 develop(intx, ZombieALotInterval, 5, \
1341 "Number of exits until ZombieALot kicks in") \
1342 \
1343 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1344 "Limit malloc allocation size from VM. Reaching a limit will " \
1345 "trigger an action (see flag). This feature requires " \
1346 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1347 "Usage:" \
1348 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1349 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1350 "sets one or more category-specific limits." \
1351 "<flag> defines the action upon reaching the limit:" \
1352 "\"fatal\": end VM with a fatal error at the allocation site" \
1353 "\"oom\" : will mimic a native OOM" \
1354 "If <flag> is omitted, \"fatal\" is the default." \
1355 "Examples:\n" \
1356 "-XX:MallocLimit=2g" \
1357 "-XX:MallocLimit=2g:oom" \
1358 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1359 \
1360 product(intx, TypeProfileWidth, 2, \
1361 "Number of receiver types to record in call/cast profile") \
1362 range(0, 8) \
1363 \
1364 develop(intx, BciProfileWidth, 2, \
1365 "Number of return bci's to record in ret profile") \
1366 \
1367 product(intx, PerMethodRecompilationCutoff, 400, \
1368 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1369 range(-1, max_intx) \
1370 \
1371 product(intx, PerBytecodeRecompilationCutoff, 200, \
1372 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1373 range(-1, max_intx) \
1374 \
1375 product(intx, PerMethodTrapLimit, 100, \
1376 "Limit on traps (of one kind) in a method (includes inlines)") \
1377 range(0, max_jint) \
1378 \
1379 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1380 "Limit on speculative traps (of one kind) in a method " \
1381 "(includes inlines)") \
1382 range(0, max_jint) \
1383 \
1384 product(intx, PerBytecodeTrapLimit, 4, \
1385 "Limit on traps (of one kind) at a particular BCI") \
1386 range(0, max_jint) \
1387 \
1388 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1389 "Extra method data trap entries for speculation") \
1390 \
1391 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1392 "Ratio of call site execution to caller method invocation") \
1393 \
1394 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1395 "Minimum ratio of call site execution to caller method" \
1396 "invocation to be considered for inlining") \
1397 \
1398 develop(intx, InlineThrowCount, 50, \
1399 "Force inlining of interpreted methods that throw this often") \
1400 range(0, max_jint) \
1401 \
1402 develop(intx, InlineThrowMaxSize, 200, \
1403 "Force inlining of throwing methods smaller than this") \
1404 range(0, max_jint) \
1405 \
1406 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1407 "Initial threshold (in bytes) at which a garbage collection " \
1408 "is done to reduce Metaspace usage") \
1409 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1410 \
1411 product(size_t, MaxMetaspaceSize, max_uintx, \
1412 "Maximum size of Metaspaces (in bytes)") \
1413 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1414 \
1415 product(size_t, CompressedClassSpaceSize, 1*G, \
1416 "Maximum size of class area in Metaspace when compressed " \
1417 "class pointers are used") \
1418 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1419 \
1420 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1421 "Force the class space to be allocated at this address or " \
1422 "fails VM initialization (requires -Xshare=off.") \
1423 \
1424 develop(bool, RandomizeClassSpaceLocation, true, \
1425 "Randomize location of class space.") \
1426 \
1427 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1428 "Print metaspace statistics upon VM exit.") \
1429 \
1430 product(bool, PrintCompilerMemoryStatisticsAtExit, false, DIAGNOSTIC, \
1431 "Print compiler memory statistics upon VM exit.") \
1432 \
1433 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1434 "The minimum percentage of heap free after GC to avoid expansion."\
1435 " For most GCs this applies to the old generation. In G1 and" \
1436 " ParallelGC it applies to the whole heap.") \
1437 range(0, 100) \
1438 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1439 \
1440 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1441 "The maximum percentage of heap free after GC to avoid shrinking."\
1442 " For most GCs this applies to the old generation. In G1 and" \
1443 " ParallelGC it applies to the whole heap.") \
1444 range(0, 100) \
1445 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1446 \
1447 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1448 "Number of milliseconds per MB of free space in the heap") \
1449 range(0, max_intx) \
1450 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1451 \
1452 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1453 "The minimum change in heap space due to GC (in bytes)") \
1454 range(0, max_uintx / 2 + 1) \
1455 \
1456 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1457 "The minimum expansion of Metaspace (in bytes)") \
1458 range(0, max_uintx) \
1459 \
1460 product(uint, MaxMetaspaceFreeRatio, 70, \
1461 "The maximum percentage of Metaspace free after GC to avoid " \
1462 "shrinking") \
1463 range(0, 100) \
1464 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1465 \
1466 product(uint, MinMetaspaceFreeRatio, 40, \
1467 "The minimum percentage of Metaspace free after GC to avoid " \
1468 "expansion") \
1469 range(0, 99) \
1470 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1471 \
1472 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1473 "The maximum expansion of Metaspace without full GC (in bytes)") \
1474 range(0, max_uintx) \
1475 \
1476 /* stack parameters */ \
1477 product_pd(intx, StackYellowPages, \
1478 "Number of yellow zone (recoverable overflows) pages of size " \
1479 "4KB. If pages are bigger yellow zone is aligned up.") \
1480 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1481 \
1482 product_pd(intx, StackRedPages, \
1483 "Number of red zone (unrecoverable overflows) pages of size " \
1484 "4KB. If pages are bigger red zone is aligned up.") \
1485 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1486 \
1487 product_pd(intx, StackReservedPages, \
1488 "Number of reserved zone (reserved to annotated methods) pages" \
1489 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1490 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1491 \
1492 product(bool, RestrictReservedStack, true, \
1493 "Restrict @ReservedStackAccess to trusted classes") \
1494 \
1495 /* greater stack shadow pages can't generate instruction to bang stack */ \
1496 product_pd(intx, StackShadowPages, \
1497 "Number of shadow zone (for overflow checking) pages of size " \
1498 "4KB. If pages are bigger shadow zone is aligned up. " \
1499 "This should exceed the depth of the VM and native call stack.") \
1500 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1501 \
1502 product_pd(intx, ThreadStackSize, \
1503 "Thread Stack Size (in Kbytes)") \
1504 range(0, 1 * M) \
1505 \
1506 product_pd(intx, VMThreadStackSize, \
1507 "Non-Java Thread Stack Size (in Kbytes)") \
1508 range(0, max_intx/(1 * K)) \
1509 \
1510 product_pd(intx, CompilerThreadStackSize, \
1511 "Compiler Thread Stack Size (in Kbytes)") \
1512 range(0, max_intx/(1 * K)) \
1513 \
1514 develop_pd(size_t, JVMInvokeMethodSlack, \
1515 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1516 \
1517 /* code cache parameters */ \
1518 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1519 "Code cache segment size (in bytes) - smallest unit of " \
1520 "allocation") \
1521 range(1, 1024) \
1522 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1523 \
1524 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1525 "Code entry alignment for generated code (in bytes)") \
1526 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1527 \
1528 product_pd(intx, OptoLoopAlignment, \
1529 "Align inner loops to zero relative to this modulus") \
1530 range(1, 128) \
1531 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1532 \
1533 product_pd(uintx, InitialCodeCacheSize, \
1534 "Initial code cache size (in bytes)") \
1535 constraint(VMPageSizeConstraintFunc, AtParse) \
1536 \
1537 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1538 "Minimum code cache size (in bytes) required to start VM.") \
1539 range(0, max_uintx) \
1540 \
1541 product(bool, SegmentedCodeCache, false, \
1542 "Use a segmented code cache") \
1543 \
1544 product_pd(uintx, ReservedCodeCacheSize, \
1545 "Reserved code cache size (in bytes) - maximum code cache size") \
1546 constraint(VMPageSizeConstraintFunc, AtParse) \
1547 \
1548 product_pd(uintx, NonProfiledCodeHeapSize, \
1549 "Size of code heap with non-profiled methods (in bytes)") \
1550 range(0, max_uintx) \
1551 \
1552 product_pd(uintx, ProfiledCodeHeapSize, \
1553 "Size of code heap with profiled methods (in bytes)") \
1554 range(0, max_uintx) \
1555 \
1556 product_pd(uintx, NonNMethodCodeHeapSize, \
1557 "Size of code heap with non-nmethods (in bytes)") \
1558 constraint(VMPageSizeConstraintFunc, AtParse) \
1559 \
1560 product_pd(uintx, CodeCacheExpansionSize, \
1561 "Code cache expansion size (in bytes)") \
1562 range(32*K, max_uintx) \
1563 \
1564 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1565 "Minimum number of segments in a code cache block") \
1566 range(1, 100) \
1567 \
1568 develop(bool, ExitOnFullCodeCache, false, \
1569 "Exit the VM if we fill the code cache") \
1570 \
1571 product(bool, UseCodeCacheFlushing, true, \
1572 "Remove cold/old nmethods from the code cache") \
1573 \
1574 product(double, SweeperThreshold, 15.0, \
1575 "Threshold when a code cache unloading GC is invoked." \
1576 "Value is percentage of ReservedCodeCacheSize.") \
1577 range(0.0, 100.0) \
1578 \
1579 product(uintx, StartAggressiveSweepingAt, 10, \
1580 "Start aggressive sweeping if X[%] of the code cache is free." \
1581 "Segmented code cache: X[%] of the non-profiled heap." \
1582 "Non-segmented code cache: X[%] of the total code cache") \
1583 range(0, 100) \
1584 \
1585 /* interpreter debugging */ \
1586 develop(intx, BinarySwitchThreshold, 5, \
1587 "Minimal number of lookupswitch entries for rewriting to binary " \
1588 "switch") \
1589 \
1590 develop(uintx, StopInterpreterAt, 0, \
1591 "Stop interpreter execution at specified bytecode number") \
1592 \
1593 develop(uintx, TraceBytecodesAt, 0, \
1594 "Trace bytecodes starting with specified bytecode number") \
1595 \
1596 develop(uintx, TraceBytecodesStopAt, 0, \
1597 "Stop bytecode tracing at the specified bytecode number") \
1598 \
1599 /* Priorities */ \
1600 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1601 \
1602 product(int, ThreadPriorityPolicy, 0, \
1603 "0 : Normal. "\
1604 " VM chooses priorities that are appropriate for normal "\
1605 " applications. "\
1606 " On Windows applications are allowed to use higher native "\
1607 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1608 " not use the highest possible native priority, "\
1609 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1610 " system threads. On Linux thread priorities are ignored "\
1611 " because the OS does not support static priority in "\
1612 " SCHED_OTHER scheduling class which is the only choice for "\
1613 " non-root, non-realtime applications. "\
1614 "1 : Aggressive. "\
1615 " Java thread priorities map over to the entire range of "\
1616 " native thread priorities. Higher Java thread priorities map "\
1617 " to higher native thread priorities. This policy should be "\
1618 " used with care, as sometimes it can cause performance "\
1619 " degradation in the application and/or the entire system. On "\
1620 " Linux/BSD/macOS this policy requires root privilege or an "\
1621 " extended capability.") \
1622 range(0, 1) \
1623 \
1624 product(bool, ThreadPriorityVerbose, false, \
1625 "Print priority changes") \
1626 \
1627 product(int, CompilerThreadPriority, -1, \
1628 "The native priority at which compiler threads should run " \
1629 "(-1 means no change)") \
1630 range(min_jint, max_jint) \
1631 \
1632 product(int, VMThreadPriority, -1, \
1633 "The native priority at which the VM thread should run " \
1634 "(-1 means no change)") \
1635 range(min_jint, max_jint) \
1636 \
1637 product(int, JavaPriority1_To_OSPriority, -1, \
1638 "Map Java priorities to OS priorities") \
1639 range(min_jint, max_jint) \
1640 \
1641 product(int, JavaPriority2_To_OSPriority, -1, \
1642 "Map Java priorities to OS priorities") \
1643 range(min_jint, max_jint) \
1644 \
1645 product(int, JavaPriority3_To_OSPriority, -1, \
1646 "Map Java priorities to OS priorities") \
1647 range(min_jint, max_jint) \
1648 \
1649 product(int, JavaPriority4_To_OSPriority, -1, \
1650 "Map Java priorities to OS priorities") \
1651 range(min_jint, max_jint) \
1652 \
1653 product(int, JavaPriority5_To_OSPriority, -1, \
1654 "Map Java priorities to OS priorities") \
1655 range(min_jint, max_jint) \
1656 \
1657 product(int, JavaPriority6_To_OSPriority, -1, \
1658 "Map Java priorities to OS priorities") \
1659 range(min_jint, max_jint) \
1660 \
1661 product(int, JavaPriority7_To_OSPriority, -1, \
1662 "Map Java priorities to OS priorities") \
1663 range(min_jint, max_jint) \
1664 \
1665 product(int, JavaPriority8_To_OSPriority, -1, \
1666 "Map Java priorities to OS priorities") \
1667 range(min_jint, max_jint) \
1668 \
1669 product(int, JavaPriority9_To_OSPriority, -1, \
1670 "Map Java priorities to OS priorities") \
1671 range(min_jint, max_jint) \
1672 \
1673 product(int, JavaPriority10_To_OSPriority,-1, \
1674 "Map Java priorities to OS priorities") \
1675 range(min_jint, max_jint) \
1676 \
1677 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1678 "Java thread priority 10 maps to critical scheduling priority") \
1679 \
1680 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1681 "Compiler thread(s) run at critical scheduling priority") \
1682 \
1683 develop(intx, NewCodeParameter, 0, \
1684 "Testing Only: Create a dedicated integer parameter before " \
1685 "putback") \
1686 \
1687 /* new oopmap storage allocation */ \
1688 develop(intx, MinOopMapAllocation, 8, \
1689 "Minimum number of OopMap entries in an OopMapSet") \
1690 \
1691 /* recompilation */ \
1692 product_pd(intx, CompileThreshold, \
1693 "number of interpreted method invocations before (re-)compiling") \
1694 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1695 \
1696 product_pd(bool, TieredCompilation, \
1697 "Enable tiered compilation") \
1698 \
1699 /* Properties for Java libraries */ \
1700 \
1701 product(uint64_t, MaxDirectMemorySize, 0, \
1702 "Maximum total size of NIO direct-buffer allocations. " \
1703 "Ignored if not explicitly set.") \
1704 range(0, max_jlong) \
1705 \
1706 /* Flags used for temporary code during development */ \
1707 \
1708 product(bool, UseNewCode, false, DIAGNOSTIC, \
1709 "Testing Only: Use the new version while testing") \
1710 \
1711 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1712 "Testing Only: Use the new version while testing") \
1713 \
1714 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1715 "Testing Only: Use the new version while testing") \
1716 \
1717 develop(bool, UseDebuggerErgo, false, \
1718 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1719 "Turns on the other UseDebuggerErgo* flags") \
1720 \
1721 develop(bool, UseDebuggerErgo1, false, \
1722 "Debugging Only: Enable workarounds for debugger induced " \
1723 "os::processor_id() >= os::processor_count() problems") \
1724 \
1725 develop(bool, UseDebuggerErgo2, false, \
1726 "Debugging Only: Limit the number of spawned JVM threads") \
1727 \
1728 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1729 "Enable JVMTI asserts related to stack depth checks") \
1730 \
1731 /* flags for performance data collection */ \
1732 \
1733 product(bool, UsePerfData, true, \
1734 "Flag to disable jvmstat instrumentation for performance testing "\
1735 "and problem isolation purposes") \
1736 \
1737 product(bool, PerfDataSaveToFile, false, \
1738 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1739 \
1740 product(ccstr, PerfDataSaveFile, nullptr, \
1741 "Save PerfData memory to the specified absolute pathname. " \
1742 "The string %p in the file name (if present) " \
1743 "will be replaced by pid") \
1744 \
1745 product(int, PerfDataSamplingInterval, 50, \
1746 "Data sampling interval (in milliseconds)") \
1747 range(PeriodicTask::min_interval, max_jint) \
1748 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1749 \
1750 product(bool, PerfDisableSharedMem, false, \
1751 "Store performance data in standard memory") \
1752 \
1753 product(int, PerfDataMemorySize, 64*K, \
1754 "Size of performance data memory region. Will be rounded " \
1755 "up to a multiple of the native os page size.") \
1756 range(128, 32*64*K) \
1757 \
1758 product(int, PerfMaxStringConstLength, 1024, \
1759 "Maximum PerfStringConstant string length before truncation") \
1760 range(32, 32*K) \
1761 \
1762 product(bool, PerfAllowAtExitRegistration, false, \
1763 "Allow registration of atexit() methods") \
1764 \
1765 product(bool, PerfBypassFileSystemCheck, false, \
1766 "Bypass Win32 file system criteria checks (Windows Only)") \
1767 \
1768 product(int, UnguardOnExecutionViolation, 0, \
1769 "Unguard page and retry on no-execute fault (Win32 only) " \
1770 "0=off, 1=conservative, 2=aggressive") \
1771 range(0, 2) \
1772 \
1773 /* Serviceability Support */ \
1774 \
1775 product(bool, ManagementServer, false, \
1776 "Create JMX Management Server") \
1777 \
1778 product(bool, DisableAttachMechanism, false, \
1779 "Disable mechanism that allows tools to attach to this VM") \
1780 \
1781 product(bool, StartAttachListener, false, \
1782 "Always start Attach Listener at VM startup") \
1783 \
1784 product(bool, EnableDynamicAgentLoading, true, \
1785 "Allow tools to load agents with the attach mechanism") \
1786 \
1787 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1788 "Print java.util.concurrent locks in thread dump") \
1789 \
1790 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1791 "Print generated stub code for method handles") \
1792 \
1793 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1794 "perform extra checks when constructing method handles") \
1795 \
1796 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1797 "show method handle implementation frames (usually hidden)") \
1798 \
1799 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1800 "show virtual threads' carrier frames in exceptions") \
1801 \
1802 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1803 "trust final non-static declarations for constant folding") \
1804 \
1805 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1806 "Optimize loads from stable fields (marked w/ @Stable)") \
1807 \
1808 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1809 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1810 "resolved before the bootstrap method is called; 1: when a BSM " \
1811 "that may accept a BootstrapCallInfo is detected, use that API " \
1812 "to pass BSM arguments, which allows the BSM to delay their " \
1813 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1814 "via that API, instead of with the eagerly-resolved array.") \
1815 \
1816 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1817 "Causes the VM to pause at startup time and wait for the pause " \
1818 "file to be removed (default: ./vm.paused.<pid>)") \
1819 \
1820 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1821 "The file to create and for whose removal to await when pausing " \
1822 "at startup. (default: ./vm.paused.<pid>)") \
1823 \
1824 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1825 "Pause and wait for keypress on exit if a debugger is attached") \
1826 \
1827 product(bool, DTraceMethodProbes, false, \
1828 "Enable dtrace tool probes for method-entry and method-exit") \
1829 \
1830 product(bool, DTraceAllocProbes, false, \
1831 "Enable dtrace tool probes for object allocation") \
1832 \
1833 product(bool, DTraceMonitorProbes, false, \
1834 "Enable dtrace tool probes for monitor events") \
1835 \
1836 product(bool, RelaxAccessControlCheck, false, \
1837 "Relax the access control checks in the verifier") \
1838 \
1839 product(uintx, StringTableSize, defaultStringTableSize, \
1840 "Number of buckets in the interned String table " \
1841 "(will be rounded to nearest higher power of 2)") \
1842 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1843 \
1844 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1845 "Number of buckets in the JVM internal Symbol table") \
1846 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1847 \
1848 product(bool, UseStringDeduplication, false, \
1849 "Use string deduplication") \
1850 \
1851 product(uint, StringDeduplicationAgeThreshold, 3, \
1852 "A string must reach this age (or be promoted to an old region) " \
1853 "to be considered for deduplication") \
1854 range(1, markWord::max_age) \
1855 \
1856 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1857 "Approximate initial number of buckets in the table") \
1858 range(1, 1 * G) \
1859 \
1860 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1861 "Entries per bucket above which the table should be expanded") \
1862 range(0.1, 1000.0) \
1863 \
1864 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1865 "Entries per bucket below which the table should be shrunk") \
1866 range(0.01, 100.0) \
1867 \
1868 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1869 "Desired entries per bucket when resizing the table") \
1870 range(0.01, 1000.0) \
1871 \
1872 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1873 "Minimum number of dead table entries for cleaning the table") \
1874 \
1875 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1876 "Minimum percentage of dead table entries for cleaning the table") \
1877 range(1, 100) \
1878 \
1879 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1880 "Force more frequent table resizing") \
1881 \
1882 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1883 "Seed for the table hashing function; 0 requests computed seed") \
1884 \
1885 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1886 "Enable internal testing APIs") \
1887 \
1888 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1889 "Accesses to all variables should always be atomic") \
1890 \
1891 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1892 "Use unaligned memory accesses in Unsafe") \
1893 \
1894 product_pd(bool, PreserveFramePointer, \
1895 "Use the FP register for holding the frame pointer " \
1896 "and not as a general purpose register.") \
1897 \
1898 product(size_t, AsyncLogBufferSize, 2*M, \
1899 "Memory budget (in bytes) for the buffer of Asynchronous " \
1900 "Logging (-Xlog:async).") \
1901 range(DEBUG_ONLY(192) NOT_DEBUG(100*K), 50*M) \
1902 \
1903 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1904 "When a class C is loaded, check that " \
1905 "(1) all intrinsics defined by the VM for class C are present "\
1906 "in the loaded class file and are marked with the " \
1907 "@IntrinsicCandidate annotation, that " \
1908 "(2) there is an intrinsic registered for all loaded methods " \
1909 "that are annotated with the @IntrinsicCandidate annotation, " \
1910 "and that " \
1911 "(3) no orphan methods exist for class C (i.e., methods for " \
1912 "which the VM declares an intrinsic but that are not declared "\
1913 "in the loaded class C. " \
1914 "Check (3) is available only in debug builds.") \
1915 \
1916 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1917 "Threshold small size (in bytes) for clearing arrays. " \
1918 "Anything this size or smaller may get converted to discrete " \
1919 "scalar stores.") \
1920 range(0, max_intx) \
1921 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1922 \
1923 product(ccstr, AllocateHeapAt, nullptr, \
1924 "Path to the directory where a temporary file will be created " \
1925 "to use as the backing store for Java Heap.") \
1926 \
1927 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1928 "Enable VM continuations support") \
1929 \
1930 develop(bool, LoomDeoptAfterThaw, false, \
1931 "Deopt stack after thaw") \
1932 \
1933 develop(bool, LoomVerifyAfterThaw, false, \
1934 "Verify stack after thaw") \
1935 \
1936 develop(bool, VerifyContinuations, false, \
1937 "Verify continuation consistency") \
1938 \
1939 develop(bool, UseContinuationFastPath, true, \
1940 "Use fast-path frame walking in continuations") \
1941 \
1942 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1943 "Run periodic metaspace verifications (0 - none, " \
1944 "1 - always, >1 every nth interval)") \
1945 \
1946 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1947 "On internal errors, include registers in error report.") \
1948 \
1949 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1950 "leverage profiling for table/lookup switch") \
1951 \
1952 develop(bool, TraceMemoryWriteback, false, \
1953 "Trace memory writeback operations") \
1954 \
1955 JFR_ONLY(product(bool, FlightRecorder, false, \
1956 "(Deprecated) Enable Flight Recorder")) \
1957 \
1958 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1959 "Flight Recorder options")) \
1960 \
1961 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1962 "Start flight recording with options")) \
1963 \
1964 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1965 "Use platform unstable time where supported for timestamps only") \
1966 \
1967 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1968 "Make nmethod barriers deoptimise a lot.") \
1969 \
1970 develop(bool, VerifyCrossModifyFence, \
1971 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1972 "Mark all threads after a safepoint, and clear on a modify " \
1973 "fence. Add cleanliness checks.") \
1974 \
1975 product(int, LockingMode, LM_LIGHTWEIGHT, \
1976 "(Deprecated) Select locking mode: " \
1977 "0: (Deprecated) monitors only (LM_MONITOR), " \
1978 "1: (Deprecated) monitors & legacy stack-locking (LM_LEGACY), " \
1979 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT, default)") \
1980 range(0, 2) \
1981 \
1982 product(bool, UseObjectMonitorTable, false, DIAGNOSTIC, \
1983 "With Lightweight Locking mode, use a table to record inflated " \
1984 "monitors rather than the first word of the object.") \
1985 \
1986 product(int, LightweightFastLockingSpins, 13, DIAGNOSTIC, \
1987 "Specifies the number of times lightweight fast locking will " \
1988 "attempt to CAS the markWord before inflating. Between each " \
1989 "CAS it will spin for exponentially more time, resulting in " \
1990 "a total number of spins on the order of O(2^value)") \
1991 range(1, 30) \
1992 \
1993 product(uint, TrimNativeHeapInterval, 0, \
1994 "Interval, in ms, at which the JVM will trim the native heap if " \
1995 "the platform supports that. Lower values will reclaim memory " \
1996 "more eagerly at the cost of higher overhead. A value of 0 " \
1997 "(default) disables native heap trimming.") \
1998 range(0, UINT_MAX) \
1999 \
2000 product(bool, ProfileVMLocks, false, DIAGNOSTIC, \
2001 "Profile VM locks usage on main thread") \
2002 \
2003 product(bool, ProfileVMCalls, false, DIAGNOSTIC, \
2004 "Profile VM calls on main thread") \
2005 \
2006 product(bool, ProfileVMOps, true, DIAGNOSTIC, \
2007 "Profile VM operations on main thread") \
2008 \
2009 product(bool, ProfileRuntimeCalls, false, DIAGNOSTIC, \
2010 "Profile calls into VM runtime on main thread") \
2011 \
2012 develop(bool, SimulateFullAddressSpace, false, \
2013 "Simulates a very populated, fragmented address space; no " \
2014 "targeted reservations will succeed.") \
2015 \
2016 product(bool, ProfileExceptionHandlers, true, \
2017 "Profile exception handlers") \
2018 \
2019 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
2020 "Unconditionally record nmethod dependencies on class " \
2021 "rewriting/transformation independently of the JVMTI " \
2022 "can_{retransform/redefine}_classes capabilities.") \
2023 \
2024 product(bool, TraceThreadTime, false, \
2025 "Enable tracing of thread time in Perf counters") \
2026 \
2027 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
2028 "Use secondary supers cache during subtype checks.") \
2029 \
2030 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
2031 "Use hash table to lookup secondary supers.") \
2032 \
2033 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
2034 "Check that linear and hashed secondary lookups return the same result.") \
2035 \
2036 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
2037 "Use a terrible hash function in order to generate many collisions.") \
2038 \
2039 develop(bool, TestAdapterLinkFailure, false, \
2040 "Test failure of adapter linking when loading from AOT cache.") \
2041 \
2042 product(bool, UseThreadsLockThrottleLock, true, DIAGNOSTIC, \
2043 "Use an extra lock during Thread start and exit to alleviate" \
2044 "contention on Threads_lock.") \
2045
2046
2047 // end of RUNTIME_FLAGS
2048
2049 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2050 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2051 DECLARE_FLAGS(RUNTIME_FLAGS)
2052 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2053
2054 #endif // SHARE_RUNTIME_GLOBALS_HPP