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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20 * or visit www.oracle.com if you need additional information or have any
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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, AOTCompatibleOopCompression, false, DIAGNOSTIC, \
128 "Always use HeapBasedNarrowOop mode, so that AOT code will " \
129 "always work regardless of runtime heap range") \
130 \
131 product(bool, UseCompactObjectHeaders, true, \
132 "Use compact 64-bit object headers in 64-bit VM") \
133 \
134 product(int, ObjectAlignmentInBytes, 8, \
135 "Default object alignment in bytes, 8 is minimum") \
136 range(8, 256) \
137 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
138
139 #else
140 // !_LP64
141
142 #define LP64_RUNTIME_FLAGS(develop, \
143 develop_pd, \
144 product, \
145 product_pd, \
146 range, \
147 constraint)
148 const bool UseCompressedOops = false;
149 const bool AOTCompatibleOopCompression = false;
150 const bool UseCompactObjectHeaders = false;
151 const int ObjectAlignmentInBytes = 8;
152
153 #endif // _LP64
154
155 // Default value for PrintAssemblyOptions, set via --with-print-assembly-options.
156 #ifndef DEFAULT_PRINT_ASSEMBLY_OPTIONS
157 #define DEFAULT_PRINT_ASSEMBLY_OPTIONS nullptr
158 #endif
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(bool, NUMAStats, false, \
213 "Print NUMA stats in detailed heap information") \
214 \
215 product(bool, UseAES, false, \
216 "Control whether AES instructions are used when available") \
217 \
218 product(bool, UseFMA, false, \
219 "Control whether FMA instructions are used when available") \
220 \
221 product(bool, UseSHA, false, \
222 "Control whether SHA instructions are used when available") \
223 \
224 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
225 "Use intrinsics for GHASH versions of crypto") \
226 \
227 product(bool, UseBASE64Intrinsics, false, \
228 "Use intrinsics for java.util.Base64") \
229 \
230 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
231 "Use intrinsics for sun.security.util.math.intpoly") \
232 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
233 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
234 \
235 product(size_t, LargePageSizeInBytes, 0, \
236 "Maximum large page size used (0 will use the default large " \
237 "page size for the environment as the maximum) " \
238 "(must be a power of 2)") \
239 range(0, max_uintx) \
240 constraint(LargePageSizeInBytesConstraintFunc, AtParse) \
241 \
242 product(size_t, LargePageHeapSizeThreshold, 128*M, \
243 "Use large pages if maximum heap is at least this big") \
244 range(0, max_uintx) \
245 \
246 product(bool, ForceTimeHighResolution, false, \
247 "Using high time resolution (for Win32 only)") \
248 \
249 develop(bool, TracePcPatching, false, \
250 "Trace usage of frame::patch_pc") \
251 \
252 develop(bool, TraceRelocator, false, \
253 "Trace the bytecode relocator") \
254 \
255 \
256 product(bool, SafepointALot, false, DIAGNOSTIC, \
257 "Generate a lot of safepoints. This works with " \
258 "GuaranteedSafepointInterval") \
259 \
260 product(bool, HandshakeALot, false, DIAGNOSTIC, \
261 "Generate a lot of handshakes. This works with " \
262 "GuaranteedSafepointInterval") \
263 \
264 product_pd(bool, BackgroundCompilation, \
265 "A thread requesting compilation is not blocked during " \
266 "compilation") \
267 \
268 product(bool, MethodFlushing, true, \
269 "Reclamation of compiled methods") \
270 \
271 develop(bool, VerifyStack, false, \
272 "Verify stack of each thread when it is entering a runtime call") \
273 \
274 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
275 "Make all non code cache addresses to be unreachable by " \
276 "forcing use of 64bit literal fixups") \
277 \
278 develop(bool, TraceDerivedPointers, false, \
279 "Trace traversal of derived pointers on stack") \
280 \
281 develop(bool, TraceCodeBlobStacks, false, \
282 "Trace stack-walk of codeblobs") \
283 \
284 develop(bool, PrintRewrites, false, \
285 "Print methods that are being rewritten") \
286 \
287 product(bool, UseInlineCaches, true, \
288 "Use Inline Caches for virtual calls ") \
289 \
290 develop(bool, VerifyInlineCaches, true, \
291 "Verify Inline Caches") \
292 \
293 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
294 "Inline arraycopy native that is known to be part of " \
295 "base library DLL") \
296 \
297 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
298 "Inline Object::hashCode() native that is known to be part " \
299 "of base library DLL") \
300 \
301 product(bool, InlineNatives, true, DIAGNOSTIC, \
302 "Inline natives that are known to be part of base library DLL") \
303 \
304 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
305 "Inline SinD, CosD, etc.") \
306 \
307 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
308 "Inline Class.isInstance, etc") \
309 \
310 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
311 "Inline Thread.currentThread, etc") \
312 \
313 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
314 "Inline memory ops (native methods) from Unsafe") \
315 \
316 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
317 "Use intrinsics for AES versions of crypto") \
318 \
319 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
320 "Use intrinsics for the paralleled version of AES/CTR crypto") \
321 \
322 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
323 "Use intrinsics for the vectorized version of ChaCha20") \
324 \
325 product(bool, UseKyberIntrinsics, false, DIAGNOSTIC, \
326 "Use intrinsics for the vectorized version of Kyber") \
327 \
328 product(bool, UseDilithiumIntrinsics, false, DIAGNOSTIC, \
329 "Use intrinsics for the vectorized version of Dilithium") \
330 \
331 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
332 "Use intrinsics for MD5 crypto hash function") \
333 \
334 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
335 "Use intrinsics for SHA-1 crypto hash function. " \
336 "Requires that UseSHA is enabled.") \
337 \
338 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
339 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
340 "Requires that UseSHA is enabled.") \
341 \
342 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
343 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
344 "Requires that UseSHA is enabled.") \
345 \
346 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
347 "Use intrinsics for SHA3 crypto hash function. " \
348 "Requires that UseSHA is enabled.") \
349 \
350 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
351 "use intrinsics for java.util.zip.CRC32") \
352 \
353 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
354 "use intrinsics for java.util.zip.CRC32C") \
355 \
356 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
357 "use intrinsics for java.util.zip.Adler32") \
358 \
359 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
360 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
361 \
362 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
363 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
364 \
365 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
366 "Enables intrinsification of Math.copySign") \
367 \
368 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
369 "Enables intrinsification of Math.signum") \
370 \
371 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
372 "Use Compiler thread for compiler's stubs generation") \
373 \
374 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
375 "do not expand intrinsics whose (internal) names appear here") \
376 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
377 \
378 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
379 "Control intrinsics using a list of +/- (internal) names, " \
380 "separated by commas") \
381 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
382 \
383 develop(bool, TraceCallFixup, false, \
384 "Trace all call fixups") \
385 \
386 develop(bool, DeoptimizeALot, false, \
387 "Deoptimize at every exit from the runtime system") \
388 \
389 develop(ccstrlist, DeoptimizeOnlyAt, "", \
390 "A comma separated list of bcis to deoptimize at") \
391 \
392 develop(bool, DeoptimizeRandom, false, \
393 "Deoptimize random frames on random exit from the runtime system")\
394 \
395 develop(bool, ZombieALot, false, \
396 "Create non-entrant nmethods at exit from the runtime system") \
397 \
398 develop(bool, WalkStackALot, false, \
399 "Trace stack (no print) at every exit from the runtime system") \
400 \
401 develop(bool, DeoptimizeObjectsALot, false, \
402 "For testing purposes concurrent threads revert optimizations " \
403 "based on escape analysis at intervals given with " \
404 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
405 "with DeoptimizeObjectsALotThreadCountSingle and " \
406 "DeoptimizeObjectsALotThreadCountAll.") \
407 \
408 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
409 "Interval for DeoptimizeObjectsALot.") \
410 range(0, max_jlong) \
411 \
412 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
413 "The number of threads that revert optimizations based on " \
414 "escape analysis for a single thread if DeoptimizeObjectsALot " \
415 "is enabled. The target thread is selected round robin." ) \
416 range(0, max_jint) \
417 \
418 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
419 "The number of threads that revert optimizations based on " \
420 "escape analysis for all threads if DeoptimizeObjectsALot " \
421 "is enabled." ) \
422 range(0, max_jint) \
423 \
424 develop(bool, VerifyLastFrame, false, \
425 "Verify oops on last frame on entry to VM") \
426 \
427 product(bool, SafepointTimeout, false, \
428 "Time out and warn or fail after SafepointTimeoutDelay " \
429 "milliseconds if failed to reach safepoint") \
430 \
431 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
432 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
433 \
434 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
435 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
436 range(0, max_jlong) \
437 \
438 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
439 "Abort upon failure to complete VM operation promptly") \
440 \
441 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
442 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
443 range(0, max_intx) \
444 \
445 product(bool, MaxFDLimit, true, \
446 "Bump the number of file descriptors to maximum (Unix only)") \
447 \
448 product(bool, LogEvents, true, DIAGNOSTIC, \
449 "Enable the various ring buffer event logs") \
450 \
451 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
452 "Number of ring buffer event logs") \
453 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
454 \
455 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
456 "Enable the Java bytecode verifier for remote classes") \
457 \
458 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
459 "Enable the Java bytecode verifier for local classes") \
460 \
461 develop(bool, VerifyStackAtCalls, false, \
462 "Verify that the stack pointer is unchanged after calls") \
463 \
464 develop(bool, TraceJavaAssertions, false, \
465 "Trace java language assertions") \
466 \
467 develop(bool, VerifyCodeCache, false, \
468 "Verify code cache on memory allocation/deallocation") \
469 \
470 develop(bool, ZapResourceArea, trueInDebug, \
471 "Zap freed resource/arena space") \
472 \
473 develop(bool, ZapVMHandleArea, trueInDebug, \
474 "Zap freed VM handle space") \
475 \
476 develop(bool, ZapStackSegments, trueInDebug, \
477 "Zap allocated/freed stack segments") \
478 \
479 develop(bool, ZapUnusedHeapArea, trueInDebug, \
480 "Zap unused heap space") \
481 \
482 develop(bool, ZapFillerObjects, trueInDebug, \
483 "Zap filler objects") \
484 \
485 develop(bool, ZapCHeap, trueInDebug, \
486 "Zap allocated/freed C heap space") \
487 \
488 develop(bool, ZapTLAB, trueInDebug, \
489 "Zap allocated TLABs") \
490 develop(bool, TestingAsyncLoggingDeathTest, false, \
491 "Recursive logging death test") \
492 develop(bool, TestingAsyncLoggingDeathTestNoCrash, false, \
493 "Recursive logging death test (no crash)") \
494 \
495 product(bool, ExecutingUnitTests, false, \
496 "Whether the JVM is running unit tests or not") \
497 \
498 develop(uint, ErrorHandlerTest, 0, \
499 "If > 0, provokes an error after VM initialization; the value " \
500 "determines which error to provoke. See controlled_crash() " \
501 "in vmError.cpp.") \
502 range(0, 18) \
503 \
504 develop(uint, TestCrashInErrorHandler, 0, \
505 "If > 0, provokes an error inside VM error handler (a secondary " \
506 "crash). see controlled_crash() in vmError.cpp") \
507 range(0, 17) \
508 \
509 develop(bool, TestSafeFetchInErrorHandler, false , \
510 "If true, tests SafeFetch inside error handler.") \
511 \
512 develop(bool, TestUnresponsiveErrorHandler, false, \
513 "If true, simulates an unresponsive error handler.") \
514 \
515 develop(bool, Verbose, false, \
516 "Print additional debugging information from other modes") \
517 \
518 develop(bool, PrintMiscellaneous, false, \
519 "Print uncategorized debugging information (requires +Verbose)") \
520 \
521 develop(bool, WizardMode, false, \
522 "Print much more debugging information") \
523 \
524 product(bool, ShowMessageBoxOnError, false, \
525 "Keep process alive on VM fatal error") \
526 \
527 product(bool, CreateCoredumpOnCrash, true, \
528 "Create core/mini dump on VM fatal error") \
529 \
530 product(uint64_t, ErrorLogTimeout, 2 * 60, \
531 "Timeout, in seconds, to limit the time spent on writing an " \
532 "error log in case of a crash.") \
533 range(0, (uint64_t)max_jlong/1000) \
534 \
535 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
536 "If enabled, show details on secondary crashes in the error log") \
537 \
538 develop(intx, TraceDwarfLevel, 0, \
539 "Debug levels for the dwarf parser") \
540 range(0, 4) \
541 \
542 product(bool, SuppressFatalErrorMessage, false, \
543 "Report NO fatal error message (avoid deadlock)") \
544 \
545 product(ccstrlist, OnError, "", \
546 "Run user-defined commands on fatal error; see VMError.cpp " \
547 "for examples") \
548 \
549 product(ccstrlist, OnOutOfMemoryError, "", \
550 "Run user-defined commands on first java.lang.OutOfMemoryError " \
551 "thrown from JVM") \
552 \
553 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
554 "Dump heap to file before any major stop-the-world GC " \
555 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
556 \
557 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
558 "Dump heap to file after any major stop-the-world GC " \
559 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
560 \
561 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
562 "Limit the number of heap dumps triggered by " \
563 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
564 "(0 means no limit)") \
565 \
566 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
567 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
568 "from JVM " \
569 "(also see HeapDumpPath, HeapDumpGzipLevel)") \
570 \
571 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
572 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
573 "or HeapDumpAfterFullGC is on, the path (filename or " \
574 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
575 "in the working directory)") \
576 \
577 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
578 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
579 "or HeapDumpAfterFullGC is on, the gzip compression " \
580 "level of the dump file. 0 (the default) disables gzip " \
581 "compression. Otherwise the level must be between 1 and 9.") \
582 range(0, 9) \
583 \
584 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
585 "Native memory tracking options") \
586 \
587 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
588 "Print native memory tracking summary data if it is on") \
589 \
590 product(bool, LogCompilation, false, DIAGNOSTIC, \
591 "Log compilation activity in detail to LogFile") \
592 \
593 product(bool, PrintCompilation, false, \
594 "Print compilations") \
595 \
596 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
597 "Repeat compilation without installing code (number of times)") \
598 range(0, max_jint) \
599 \
600 product(bool, PrintExtendedThreadInfo, false, \
601 "Print more information in thread dump") \
602 \
603 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
604 "0: do not allow scavengable oops in the code cache; " \
605 "1: allow scavenging from the code cache; " \
606 "2: emit as many constants as the compiler can see") \
607 range(0, 2) \
608 \
609 product(bool, AlwaysRestoreFPU, false, \
610 "Restore the FPU control word after every JNI call (expensive)") \
611 \
612 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
613 "Print additional statistics per compilation") \
614 \
615 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
616 "Print code generated for i2c/c2i adapters") \
617 \
618 develop(bool, VerifyAdapterSharing, false, \
619 "Verify that the code for shared adapters is the equivalent") \
620 \
621 product(bool, PrintAssembly, false, DIAGNOSTIC, \
622 "Print assembly code (using external disassembler.so)") \
623 \
624 product(ccstr, PrintAssemblyOptions, DEFAULT_PRINT_ASSEMBLY_OPTIONS, \
625 DIAGNOSTIC, \
626 "Print options string passed to disassembler.so") \
627 \
628 develop(bool, PrintNMethodStatistics, false, \
629 "Print a summary statistic for the generated nmethods") \
630 \
631 product(bool, PrintNMethods, false, DIAGNOSTIC, \
632 "Print assembly code for nmethods when generated") \
633 \
634 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
635 "Print assembly code for native nmethods when generated") \
636 \
637 develop(bool, PrintDebugInfo, false, \
638 "Print debug information for all nmethods when generated") \
639 \
640 develop(bool, PrintRelocations, false, \
641 "Print relocation information for all nmethods when generated") \
642 \
643 develop(bool, PrintDependencies, false, \
644 "Print dependency information for all nmethods when generated") \
645 \
646 develop(bool, PrintExceptionHandlers, false, \
647 "Print exception handler tables for all nmethods when generated") \
648 \
649 develop(bool, StressCompiledExceptionHandlers, false, \
650 "Exercise compiled exception handlers") \
651 \
652 product(bool, DeoptimizeOnAllocationException, false, DIAGNOSTIC, \
653 "Deoptimize on exception during allocation instead of using the " \
654 "compiled exception handlers") \
655 \
656 develop(bool, InterceptOSException, false, \
657 "Start debugger when an implicit OS (e.g. null pointer) " \
658 "exception happens") \
659 \
660 product(bool, PrintCodeCache, false, \
661 "Print the code cache memory usage when exiting") \
662 \
663 develop(bool, PrintCodeCache2, false, \
664 "Print detailed usage information on the code cache when exiting")\
665 \
666 product(bool, PrintCodeCacheOnCompilation, false, \
667 "Print the code cache memory usage each time a method is " \
668 "compiled") \
669 \
670 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
671 "Print code heap usage statistics on exit and on full condition") \
672 \
673 product(bool, PrintStubCode, false, DIAGNOSTIC, \
674 "Print generated stub code") \
675 \
676 product(bool, StackTraceInThrowable, true, \
677 "Collect backtrace in throwable when exception happens") \
678 \
679 product(bool, OmitStackTraceInFastThrow, true, \
680 "Omit backtraces for some 'hot' exceptions in optimized code") \
681 \
682 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
683 "Show exception messages from RuntimeExceptions that contain " \
684 "snippets of the failing code. Disable this to improve privacy.") \
685 \
686 product(bool, PrintWarnings, true, \
687 "Print JVM warnings to output stream") \
688 \
689 develop(bool, RegisterReferences, true, \
690 "Tell whether the VM should register soft/weak/final/phantom " \
691 "references") \
692 \
693 develop(bool, PrintCodeCacheExtension, false, \
694 "Print extension of code cache") \
695 \
696 product(bool, ClassUnloading, true, \
697 "Do unloading of classes") \
698 \
699 product(bool, ClassUnloadingWithConcurrentMark, true, \
700 "Do unloading of classes with a concurrent marking cycle") \
701 \
702 develop(bool, PrintSystemDictionaryAtExit, false, \
703 "Print the system dictionary at exit") \
704 \
705 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
706 "Print the class loader data graph at exit") \
707 \
708 product(bool, PrintVMInfoAtExit, false, DIAGNOSTIC, \
709 "Executes the VM.info diagnostic command at exit") \
710 \
711 product(bool, AllowParallelDefineClass, false, \
712 "Allow parallel defineClass requests for class loaders " \
713 "registering as parallel capable") \
714 \
715 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
716 "Disable the use of stack guard pages if the JVM is loaded " \
717 "on the primordial process thread") \
718 \
719 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
720 "Do JVMTI virtual thread mount/unmount transitions " \
721 "(disabling this flag implies no JVMTI events are posted)") \
722 \
723 /* notice: the max range value here is max_jint, not max_intx */ \
724 /* because of overflow issue */ \
725 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
726 "Async deflate idle monitors every so many milliseconds when " \
727 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
728 range(0, max_jint) \
729 \
730 /* notice: the max range value here is max_jint, not max_intx */ \
731 /* because of overflow issue */ \
732 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
733 "Async deflate idle monitors every so many milliseconds even " \
734 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
735 range(0, max_jint) \
736 \
737 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
738 "Used to estimate a variable ceiling based on number of threads " \
739 "for use with MonitorUsedDeflationThreshold (0 is off).") \
740 range(0, max_uintx) \
741 \
742 /* notice: the max range value here is max_jint, not max_intx */ \
743 /* because of overflow issue */ \
744 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
745 "The maximum number of monitors to deflate, unlink and delete " \
746 "at one time (minimum is 1024).") \
747 range(1024, max_jint) \
748 \
749 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
750 "The maximum number of monitors to unlink in one batch. ") \
751 range(1, max_jint) \
752 \
753 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
754 "Percentage of used monitors before triggering deflation (0 is " \
755 "off). The check is performed on AsyncDeflationInterval or " \
756 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
757 range(0, 100) \
758 \
759 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
760 "Max number of no progress async deflation attempts to tolerate " \
761 "before adjusting the in_use_list_ceiling up (0 is off).") \
762 range(0, max_uintx) \
763 \
764 product(intx, hashCode, 5, EXPERIMENTAL, \
765 "(Unstable) select hashCode generation algorithm") \
766 \
767 product(bool, ReduceSignalUsage, false, \
768 "Reduce the use of OS signals in Java and/or the VM") \
769 \
770 develop(bool, LoadLineNumberTables, true, \
771 "Tell whether the class file parser loads line number tables") \
772 \
773 develop(bool, LoadLocalVariableTables, true, \
774 "Tell whether the class file parser loads local variable tables") \
775 \
776 develop(bool, LoadLocalVariableTypeTables, true, \
777 "Tell whether the class file parser loads local variable type" \
778 "tables") \
779 \
780 product(bool, AllowUserSignalHandlers, false, \
781 "Application will install primary signal handlers for the JVM " \
782 "(Unix only)") \
783 \
784 product(bool, UseSignalChaining, true, \
785 "Use signal-chaining to invoke signal handlers installed " \
786 "by the application (Unix only)") \
787 \
788 product(bool, RestoreMXCSROnJNICalls, false, \
789 "Restore MXCSR when returning from JNI calls") \
790 \
791 product(bool, CheckJNICalls, false, \
792 "Verify all arguments to JNI calls") \
793 \
794 product(bool, UseFastJNIAccessors, true, \
795 "Use optimized versions of Get<Primitive>Field") \
796 \
797 product(intx, MaxJNILocalCapacity, 65536, \
798 "Maximum allowable local JNI handle capacity to " \
799 "EnsureLocalCapacity() and PushLocalFrame(), " \
800 "where <= 0 is unlimited, default: 65536") \
801 range(min_intx, max_intx) \
802 \
803 product(bool, EagerXrunInit, false, \
804 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
805 "but not all -Xrun libraries may support the state of the VM " \
806 "at this time") \
807 \
808 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
809 "Number of OutOfMemoryErrors preallocated with backtrace") \
810 range(0, 1024) \
811 \
812 develop(bool, PrintFieldLayout, false, \
813 "Print field layout for each class") \
814 \
815 /* Need to limit the extent of the padding to reasonable size. */\
816 /* 8K is well beyond the reasonable HW cache line size, even with */\
817 /* aggressive prefetching, while still leaving the room for segregating */\
818 /* among the distinct pages. */\
819 product(int, ContendedPaddingWidth, 128, \
820 "How many bytes to pad the fields/classes marked @Contended with")\
821 range(0, 8192) \
822 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
823 \
824 product(bool, EnableContended, true, \
825 "Enable @Contended annotation support") \
826 \
827 product(bool, RestrictContended, true, \
828 "Restrict @Contended to trusted classes") \
829 \
830 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
831 "Detect and take action upon identifying synchronization on " \
832 "value based classes. Modes: " \
833 "0: off; " \
834 "1: exit with fatal error; " \
835 "2: log message to stdout. Output file can be specified with " \
836 " -Xlog:valuebasedclasses. If JFR is running it will " \
837 " also generate JFR events.") \
838 range(0, 2) \
839 \
840 product(bool, ExitOnOutOfMemoryError, false, \
841 "JVM exits on the first occurrence of an out-of-memory error " \
842 "thrown from JVM") \
843 \
844 product(bool, CrashOnOutOfMemoryError, false, \
845 "JVM aborts, producing an error log and core/mini dump, on the " \
846 "first occurrence of an out-of-memory error thrown from JVM") \
847 \
848 product(intx, UserThreadWaitAttemptsAtExit, 30, \
849 "The number of times to wait for user threads to stop executing " \
850 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
851 "The maximum number of waits is 1000, to wait at most 10 " \
852 "seconds.") \
853 range(0, 1000) \
854 \
855 /* tracing */ \
856 \
857 develop(bool, StressRewriter, false, \
858 "Stress linktime bytecode rewriting") \
859 \
860 product(ccstr, TraceJVMTI, nullptr, \
861 "Trace flags for JVMTI functions and events") \
862 \
863 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
864 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
865 "This option can change an EMCP method into an obsolete method " \
866 "and can affect tests that expect specific methods to be EMCP. " \
867 "This option should be used with caution.") \
868 \
869 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
870 "(Deprecated) Allow redefinition to add and delete private " \
871 "static or final methods for compatibility with old releases") \
872 \
873 develop(bool, TraceBytecodes, false, \
874 "Trace bytecode execution") \
875 \
876 develop(bool, TraceBytecodesTruncated, false, \
877 "Truncate non control-flow bytecode when tracing bytecode") \
878 \
879 develop(bool, VerifyDependencies, trueInDebug, \
880 "Exercise and verify the compilation dependency mechanism") \
881 \
882 develop(bool, TimeOopMap, false, \
883 "Time calls to GenerateOopMap::compute_map() in sum") \
884 \
885 develop(bool, GenerateOopMapALot, false, \
886 "Generate interpreter oopmaps at all safepoints") \
887 \
888 develop(bool, TraceFinalizerRegistration, false, \
889 "Trace registration of final references") \
890 \
891 product(bool, IgnoreEmptyClassPaths, false, \
892 "Ignore empty path elements in -classpath") \
893 \
894 product(bool, PrintHeapAtSIGBREAK, true, \
895 "Print heap layout in response to SIGBREAK") \
896 \
897 product(bool, PrintClassHistogram, false, MANAGEABLE, \
898 "Print a histogram of class instances") \
899 \
900 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
901 "The percentage of the used heap that the instances of a class " \
902 "must occupy for the class to generate a trace event") \
903 range(0.0, 100.0) \
904 \
905 /* JVMTI heap profiling */ \
906 \
907 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
908 "Verify memory system before JVMTI iteration") \
909 \
910 /* compiler */ \
911 \
912 /* notice: the max range value here is max_jint, not max_intx */ \
913 /* because of overflow issue */ \
914 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
915 "Number of compiler threads to run") \
916 range(0, max_jint) \
917 constraint(CICompilerCountConstraintFunc, AfterErgo) \
918 \
919 product(bool, UseDynamicNumberOfCompilerThreads, true, \
920 "Dynamically choose the number of parallel compiler threads") \
921 \
922 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
923 "Reduce the number of parallel compiler threads when they " \
924 "are not used") \
925 \
926 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
927 "Trace creation and removal of compiler threads") \
928 \
929 product(ccstr, LogClassLoadingCauseFor, nullptr, \
930 "Apply -Xlog:class+load+cause* to classes whose fully " \
931 "qualified name contains this string (\"*\" matches " \
932 "any class).") \
933 \
934 develop(bool, InjectCompilerCreationFailure, false, \
935 "Inject thread creation failures for " \
936 "UseDynamicNumberOfCompilerThreads") \
937 \
938 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
939 "Generate code for implicit null checks") \
940 \
941 product_pd(bool, TrapBasedNullChecks, \
942 "Generate code for null checks that uses a cmp and trap " \
943 "instruction raising SIGTRAP. This is only used if an access to" \
944 "null (+offset) will not raise a SIGSEGV, i.e.," \
945 "ImplicitNullChecks don't work (PPC64).") \
946 \
947 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
948 "Enable Thread SMR Statistics") \
949 \
950 product(bool, Inline, true, \
951 "Enable inlining") \
952 \
953 product(bool, ClipInlining, true, \
954 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
955 \
956 develop(bool, UseCHA, true, \
957 "Enable CHA") \
958 \
959 product(bool, UseTypeProfile, true, \
960 "Check interpreter profile for historically monomorphic calls") \
961 \
962 product(bool, PrintInlining, false, DIAGNOSTIC, \
963 "Print inlining optimizations") \
964 \
965 product(bool, UsePopCountInstruction, false, \
966 "Use population count instruction") \
967 \
968 develop(bool, TraceMethodReplacement, false, \
969 "Print when methods are replaced do to recompilation") \
970 \
971 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
972 "Minimum number of sweeper passes before an nmethod " \
973 "can be flushed") \
974 range(0, max_intx) \
975 \
976 develop(bool, StressCodeBuffers, false, \
977 "Exercise code buffer expansion and other rare state changes") \
978 \
979 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
980 "Generate extra debugging information for non-safepoints in " \
981 "nmethods") \
982 \
983 product(bool, PrintVMOptions, false, \
984 "Print flags that appeared on the command line") \
985 \
986 product(bool, IgnoreUnrecognizedVMOptions, false, \
987 "Ignore unrecognized VM options") \
988 \
989 product(bool, PrintCommandLineFlags, false, \
990 "Print flags specified on command line or set by ergonomics") \
991 \
992 product(bool, PrintFlagsInitial, false, \
993 "Print all VM flags before argument processing and exit VM") \
994 \
995 product(bool, PrintFlagsFinal, false, \
996 "Print all VM flags after argument and ergonomic processing") \
997 \
998 develop(bool, PrintFlagsWithComments, false, \
999 "Print all VM flags with default values and descriptions and " \
1000 "exit") \
1001 \
1002 product(bool, PrintFlagsRanges, false, \
1003 "Print VM flags and their ranges") \
1004 \
1005 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1006 "Use a mutex to serialize output to tty and LogFile") \
1007 \
1008 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1009 "Display all VM output on the tty, independently of LogVMOutput") \
1010 \
1011 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1012 "Save VM output to LogFile") \
1013 \
1014 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1015 "If LogVMOutput or LogCompilation is on, save VM output to " \
1016 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1017 \
1018 product(ccstr, ErrorFile, nullptr, \
1019 "If an error occurs, save the error data to this file " \
1020 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1021 \
1022 product(bool, ExtensiveErrorReports, \
1023 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1024 "Error reports are more extensive.") \
1025 \
1026 product(bool, DisplayVMOutputToStderr, false, \
1027 "If DisplayVMOutput is true, display all VM output to stderr") \
1028 \
1029 product(bool, DisplayVMOutputToStdout, false, \
1030 "If DisplayVMOutput is true, display all VM output to stdout") \
1031 \
1032 product(bool, ErrorFileToStderr, false, \
1033 "If true, error data is printed to stderr instead of a file") \
1034 \
1035 product(bool, ErrorFileToStdout, false, \
1036 "If true, error data is printed to stdout instead of a file") \
1037 \
1038 product(bool, PrintStringTableStatistics, false, \
1039 "print statistics about the StringTable and SymbolTable") \
1040 \
1041 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1042 "verify StringTable contents at exit") \
1043 \
1044 develop(bool, PrintSymbolTableSizeHistogram, false, \
1045 "print histogram of the symbol table") \
1046 \
1047 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1048 "Call fatal if this exception is thrown. Example: " \
1049 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1050 \
1051 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1052 "Call fatal if the exception pointed by AbortVMOnException " \
1053 "has this message") \
1054 \
1055 develop(bool, DebugVtables, false, \
1056 "add debugging code to vtable dispatch") \
1057 \
1058 product(bool, RangeCheckElimination, true, \
1059 "Eliminate range checks") \
1060 \
1061 develop_pd(bool, UncommonNullCast, \
1062 "track occurrences of null in casts; adjust compiler tactics") \
1063 \
1064 develop(bool, TypeProfileCasts, true, \
1065 "treat casts like calls for purposes of type profiling") \
1066 \
1067 develop(bool, TraceLivenessGen, false, \
1068 "Trace the generation of liveness analysis information") \
1069 \
1070 develop(bool, TraceLivenessQuery, false, \
1071 "Trace queries of liveness analysis information") \
1072 \
1073 develop(bool, CollectIndexSetStatistics, false, \
1074 "Collect information about IndexSets") \
1075 \
1076 /* This value is later shifted left by up to LogBytesPerLong bits */\
1077 /* (to convert from element count to size in bytes), so we must ensure */\
1078 /* it does not overflow during the shift. */\
1079 develop(int, FastAllocateSizeLimit, 128*K, \
1080 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1081 "Inline allocations larger than this in doublewords must go slow")\
1082 range(0, (1 << (BitsPerInt - LogBytesPerLong - 1)) - 1) \
1083 \
1084 product_pd(bool, CompactStrings, \
1085 "Enable Strings to use single byte chars in backing store") \
1086 \
1087 product_pd(uint, TypeProfileLevel, \
1088 "=XYZ, with Z: Type profiling of arguments at call; " \
1089 "Y: Type profiling of return value at call; " \
1090 "X: Type profiling of parameters to methods; " \
1091 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1092 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1093 \
1094 product(int, TypeProfileArgsLimit, 2, \
1095 "max number of call arguments to consider for type profiling") \
1096 range(0, 16) \
1097 \
1098 product(int, TypeProfileParmsLimit, 2, \
1099 "max number of incoming parameters to consider for type profiling"\
1100 ", -1 for all") \
1101 range(-1, 64) \
1102 \
1103 /* statistics */ \
1104 develop(bool, CountCompiledCalls, false, \
1105 "Count method invocations") \
1106 \
1107 develop(bool, ICMissHistogram, false, \
1108 "Produce histogram of IC misses") \
1109 \
1110 /* interpreter */ \
1111 product_pd(bool, RewriteBytecodes, \
1112 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1113 \
1114 product_pd(bool, RewriteFrequentPairs, \
1115 "Rewrite frequently used bytecode pairs into a single bytecode") \
1116 \
1117 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1118 "Print the generated interpreter code") \
1119 \
1120 product(bool, UseInterpreter, true, \
1121 "Use interpreter for non-compiled methods") \
1122 \
1123 develop(bool, UseFastSignatureHandlers, true, \
1124 "Use fast signature handlers for native calls") \
1125 \
1126 product(bool, UseLoopCounter, true, \
1127 "Increment invocation counter on backward branch") \
1128 \
1129 product_pd(bool, UseOnStackReplacement, \
1130 "Use on stack replacement, calls runtime if invoc. counter " \
1131 "overflows in loop") \
1132 \
1133 develop(bool, TraceOnStackReplacement, false, \
1134 "Trace on stack replacement") \
1135 \
1136 product_pd(bool, PreferInterpreterNativeStubs, \
1137 "Use always interpreter stubs for native methods invoked via " \
1138 "interpreter") \
1139 \
1140 develop(bool, CountBytecodes, false, \
1141 "Count number of bytecodes executed") \
1142 \
1143 develop(bool, PrintBytecodeHistogram, false, \
1144 "Print histogram of the executed bytecodes") \
1145 \
1146 develop(bool, PrintBytecodePairHistogram, false, \
1147 "Print histogram of the executed bytecode pairs") \
1148 \
1149 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1150 "Print code generated for native method signature handlers") \
1151 \
1152 develop(bool, VerifyOops, false, \
1153 "Do plausibility checks for oops") \
1154 \
1155 develop(bool, CheckUnhandledOops, false, \
1156 "Check for unhandled oops in VM code") \
1157 \
1158 develop(bool, VerifyJNIFields, trueInDebug, \
1159 "Verify jfieldIDs for instance fields") \
1160 \
1161 develop(bool, VerifyActivationFrameSize, false, \
1162 "Verify that activation frame didn't become smaller than its " \
1163 "minimal size") \
1164 \
1165 develop(bool, TraceFrequencyInlining, false, \
1166 "Trace frequency based inlining") \
1167 \
1168 develop_pd(bool, InlineIntrinsics, \
1169 "Use intrinsics in Interpreter that can be statically resolved") \
1170 \
1171 product_pd(bool, ProfileInterpreter, \
1172 "Profile at the bytecode level during interpretation") \
1173 \
1174 develop_pd(bool, ProfileTraps, \
1175 "Profile deoptimization traps at the bytecode level") \
1176 \
1177 product(intx, ProfileMaturityPercentage, 20, \
1178 "number of method invocations/branches (expressed as % of " \
1179 "CompileThreshold) before using the method's profile") \
1180 range(0, 100) \
1181 \
1182 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1183 "Print the results of +ProfileInterpreter at end of run") \
1184 \
1185 develop(bool, VerifyDataPointer, trueInDebug, \
1186 "Verify the method data pointer during interpreter profiling") \
1187 \
1188 develop(bool, CrashGCForDumpingJavaThread, false, \
1189 "Manually make GC thread crash then dump java stack trace; " \
1190 "Test only") \
1191 \
1192 /* compilation */ \
1193 product(bool, UseCompiler, true, \
1194 "Use Just-In-Time compilation") \
1195 \
1196 product(bool, AlwaysCompileLoopMethods, false, \
1197 "(Deprecated) When using recompilation, never interpret methods " \
1198 "containing loops") \
1199 \
1200 product(int, AllocatePrefetchStyle, 1, \
1201 "0 = no prefetch, " \
1202 "1 = generate prefetch instructions for each allocation, " \
1203 "2 = use TLAB watermark to gate allocation prefetch, " \
1204 "3 = generate one prefetch instruction per cache line") \
1205 range(0, 3) \
1206 \
1207 product(int, AllocatePrefetchDistance, -1, \
1208 "Distance to prefetch ahead of allocation pointer. " \
1209 "-1: use system-specific value (automatically determined") \
1210 range(-1, 512) \
1211 \
1212 product(int, AllocatePrefetchLines, 3, \
1213 "Number of lines to prefetch ahead of array allocation pointer") \
1214 range(1, 64) \
1215 \
1216 product(int, AllocateInstancePrefetchLines, 1, \
1217 "Number of lines to prefetch ahead of instance allocation " \
1218 "pointer") \
1219 range(1, 64) \
1220 \
1221 product(int, AllocatePrefetchStepSize, 16, \
1222 "Step size in bytes of sequential prefetch instructions") \
1223 range(1, 512) \
1224 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1225 \
1226 product(intx, AllocatePrefetchInstr, 0, \
1227 "Select instruction to prefetch ahead of allocation pointer") \
1228 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1229 \
1230 /* deoptimization */ \
1231 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1232 "Trace deoptimization") \
1233 \
1234 develop(bool, PrintDeoptimizationDetails, false, \
1235 "Print more information about deoptimization") \
1236 \
1237 develop(bool, DebugDeoptimization, false, \
1238 "Tracing various information while debugging deoptimization") \
1239 \
1240 product(double, SelfDestructTimer, 0.0, \
1241 "Will cause VM to terminate after a given time " \
1242 "(in fractional minutes) " \
1243 "(0.0 means off)") \
1244 range(0.0, (double)max_intx) \
1245 \
1246 product(int, MaxJavaStackTraceDepth, 1024, \
1247 "The maximum number of lines in the stack trace for Java " \
1248 "exceptions (0 means all)") \
1249 range(0, max_jint/2) \
1250 \
1251 /* notice: the max range value here is max_jint, not max_intx */ \
1252 /* because of overflow issue */ \
1253 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1254 "Guarantee a safepoint (at least) every so many milliseconds " \
1255 "(0 means none)") \
1256 range(0, max_jint) \
1257 \
1258 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1259 "Wake the ServiceThread to do periodic cleanup checks every so " \
1260 "many milliseconds (0 means none)") \
1261 range(0, max_jint) \
1262 \
1263 product(double, SafepointTimeoutDelay, 10000, \
1264 "Delay in milliseconds for option SafepointTimeout; " \
1265 "supports sub-millisecond resolution with fractional values.") \
1266 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1267 \
1268 product(bool, UseSystemMemoryBarrier, false, \
1269 "Try to enable system memory barrier if supported by OS") \
1270 \
1271 product(intx, NmethodSweepActivity, 4, \
1272 "Removes cold nmethods from code cache if > 0. Higher values " \
1273 "result in more aggressive sweeping") \
1274 range(0, 2000) \
1275 \
1276 develop(intx, MallocCatchPtr, -1, \
1277 "Hit breakpoint when mallocing/freeing this pointer") \
1278 \
1279 develop(int, StackPrintLimit, 100, \
1280 "number of stack frames to print in VM-level stack dump") \
1281 \
1282 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1283 "max number of compiled code units to print in error log") \
1284 range(0, VMError::max_error_log_print_code) \
1285 \
1286 develop(int, MaxElementPrintSize, 256, \
1287 "maximum number of elements to print") \
1288 \
1289 develop(int, MaxStringPrintSize, 256, \
1290 "maximum number of characters to print for a java.lang.String " \
1291 "in the VM. If exceeded, an abridged version of the string is " \
1292 "printed with the middle of the string elided.") \
1293 range(2, O_BUFLEN) \
1294 \
1295 develop(intx, MaxSubklassPrintSize, 4, \
1296 "maximum number of subklasses to print when printing klass") \
1297 \
1298 develop(intx, MaxForceInlineLevel, 100, \
1299 "maximum number of nested calls that are forced for inlining " \
1300 "(using CompileCommand or marked w/ @ForceInline)") \
1301 range(0, max_jint) \
1302 \
1303 develop(intx, MethodHistogramCutoff, 100, \
1304 "The cutoff value for method invocation histogram (+CountCalls)") \
1305 \
1306 develop(intx, DeoptimizeALotInterval, 5, \
1307 "Number of exits until DeoptimizeALot kicks in") \
1308 \
1309 develop(intx, ZombieALotInterval, 5, \
1310 "Number of exits until ZombieALot kicks in") \
1311 \
1312 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1313 "Limit malloc allocation size from VM. Reaching a limit will " \
1314 "trigger an action (see flag). This feature requires " \
1315 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1316 "Usage:" \
1317 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1318 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1319 "sets one or more category-specific limits." \
1320 "<flag> defines the action upon reaching the limit:" \
1321 "\"fatal\": end VM with a fatal error at the allocation site" \
1322 "\"oom\" : will mimic a native OOM" \
1323 "If <flag> is omitted, \"fatal\" is the default." \
1324 "Examples:\n" \
1325 "-XX:MallocLimit=2g" \
1326 "-XX:MallocLimit=2g:oom" \
1327 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1328 \
1329 product(intx, TypeProfileWidth, 2, \
1330 "Number of receiver types to record in call/cast profile") \
1331 range(0, 8) \
1332 \
1333 develop(intx, BciProfileWidth, 2, \
1334 "Number of return bci's to record in ret profile") \
1335 \
1336 product(intx, PerMethodRecompilationCutoff, 400, \
1337 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1338 range(-1, max_intx) \
1339 \
1340 product(intx, PerBytecodeRecompilationCutoff, 200, \
1341 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1342 range(-1, max_intx) \
1343 \
1344 product(intx, PerMethodTrapLimit, 100, \
1345 "Limit on traps (of one kind) in a method (includes inlines)") \
1346 range(0, max_jint) \
1347 \
1348 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1349 "Limit on speculative traps (of one kind) in a method " \
1350 "(includes inlines)") \
1351 range(0, max_jint) \
1352 \
1353 product(intx, PerBytecodeTrapLimit, 4, \
1354 "Limit on traps (of one kind) at a particular BCI") \
1355 range(0, max_jint) \
1356 \
1357 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1358 "Extra method data trap entries for speculation") \
1359 range(0, 100) \
1360 \
1361 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1362 "Ratio of call site execution to caller method invocation") \
1363 \
1364 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1365 "Minimum ratio of call site execution to caller method" \
1366 "invocation to be considered for inlining") \
1367 \
1368 develop(intx, InlineThrowCount, 50, \
1369 "Force inlining of interpreted methods that throw this often") \
1370 range(0, max_jint) \
1371 \
1372 develop(intx, InlineThrowMaxSize, 200, \
1373 "Force inlining of throwing methods smaller than this") \
1374 range(0, max_jint) \
1375 \
1376 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1377 "Initial threshold (in bytes) at which a garbage collection " \
1378 "is done to reduce Metaspace usage") \
1379 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1380 \
1381 product(size_t, MaxMetaspaceSize, max_uintx, \
1382 "Maximum size of Metaspaces (in bytes)") \
1383 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1384 \
1385 product(size_t, CompressedClassSpaceSize, 1*G, \
1386 "Maximum size of class area in Metaspace when compressed " \
1387 "class pointers are used") \
1388 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1389 \
1390 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1391 "Force the class space to be allocated at this address or " \
1392 "fails VM initialization (requires -Xshare=off.") \
1393 \
1394 develop(bool, RandomizeClassSpaceLocation, true, \
1395 "Randomize location of class space.") \
1396 \
1397 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1398 "Print metaspace statistics upon VM exit.") \
1399 \
1400 product(bool, PrintCompilerMemoryStatisticsAtExit, false, DIAGNOSTIC, \
1401 "Print compiler memory statistics upon VM exit.") \
1402 \
1403 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1404 "The minimum percentage of heap free after GC to avoid expansion."\
1405 " For most GCs this applies to the old generation. In G1 and" \
1406 " ParallelGC it applies to the whole heap.") \
1407 range(0, 100) \
1408 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1409 \
1410 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1411 "The maximum percentage of heap free after GC to avoid shrinking."\
1412 " For most GCs this applies to the old generation. In G1 and" \
1413 " ParallelGC it applies to the whole heap.") \
1414 range(0, 100) \
1415 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1416 \
1417 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1418 "Number of milliseconds per MB of free space in the heap") \
1419 range(0, max_intx) \
1420 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1421 \
1422 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1423 "The minimum change in heap space due to GC (in bytes)") \
1424 range(0, max_uintx / 2 + 1) \
1425 \
1426 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1427 "The minimum expansion of Metaspace (in bytes)") \
1428 range(0, max_uintx) \
1429 \
1430 product(uint, MaxMetaspaceFreeRatio, 70, \
1431 "The maximum percentage of Metaspace free after GC to avoid " \
1432 "shrinking") \
1433 range(0, 100) \
1434 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1435 \
1436 product(uint, MinMetaspaceFreeRatio, 40, \
1437 "The minimum percentage of Metaspace free after GC to avoid " \
1438 "expansion") \
1439 range(0, 99) \
1440 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1441 \
1442 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1443 "The maximum expansion of Metaspace without full GC (in bytes)") \
1444 range(0, max_uintx) \
1445 \
1446 /* stack parameters */ \
1447 product_pd(intx, StackYellowPages, \
1448 "Number of yellow zone (recoverable overflows) pages of size " \
1449 "4KB. If pages are bigger yellow zone is aligned up.") \
1450 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1451 \
1452 product_pd(intx, StackRedPages, \
1453 "Number of red zone (unrecoverable overflows) pages of size " \
1454 "4KB. If pages are bigger red zone is aligned up.") \
1455 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1456 \
1457 product_pd(intx, StackReservedPages, \
1458 "Number of reserved zone (reserved to annotated methods) pages" \
1459 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1460 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1461 \
1462 product(bool, RestrictReservedStack, true, \
1463 "Restrict @ReservedStackAccess to trusted classes") \
1464 \
1465 /* greater stack shadow pages can't generate instruction to bang stack */ \
1466 product_pd(intx, StackShadowPages, \
1467 "Number of shadow zone (for overflow checking) pages of size " \
1468 "4KB. If pages are bigger shadow zone is aligned up. " \
1469 "This should exceed the depth of the VM and native call stack.") \
1470 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1471 \
1472 product_pd(intx, ThreadStackSize, \
1473 "Thread Stack Size (in Kbytes)") \
1474 range(0, 1 * M) \
1475 \
1476 product_pd(intx, VMThreadStackSize, \
1477 "Non-Java Thread Stack Size (in Kbytes)") \
1478 range(0, max_intx/(1 * K)) \
1479 \
1480 product_pd(intx, CompilerThreadStackSize, \
1481 "Compiler Thread Stack Size (in Kbytes)") \
1482 range(0, max_intx/(1 * K)) \
1483 \
1484 develop_pd(size_t, JVMInvokeMethodSlack, \
1485 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1486 \
1487 /* code cache parameters */ \
1488 product_pd(size_t, CodeCacheSegmentSize, EXPERIMENTAL, \
1489 "Code cache segment size (in bytes) - smallest unit of " \
1490 "allocation") \
1491 range(1, 1024) \
1492 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1493 \
1494 product_pd(uint, CodeEntryAlignment, EXPERIMENTAL, \
1495 "Code entry alignment for generated code" \
1496 " (in bytes, power of two)") \
1497 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1498 \
1499 product_pd(intx, OptoLoopAlignment, \
1500 "Align inner loops to zero relative to this modulus") \
1501 range(1, 128) \
1502 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1503 \
1504 product_pd(size_t, InitialCodeCacheSize, \
1505 "Initial code cache size (in bytes)") \
1506 constraint(VMPageSizeConstraintFunc, AtParse) \
1507 \
1508 develop_pd(size_t, CodeCacheMinimumUseSpace, \
1509 "Minimum code cache size (in bytes) required to start VM.") \
1510 range(0, SIZE_MAX) \
1511 \
1512 product(bool, SegmentedCodeCache, false, \
1513 "Use a segmented code cache") \
1514 \
1515 product_pd(size_t, ReservedCodeCacheSize, \
1516 "Reserved code cache size (in bytes) - maximum code cache size") \
1517 constraint(VMPageSizeConstraintFunc, AtParse) \
1518 \
1519 product_pd(size_t, NonProfiledCodeHeapSize, \
1520 "Size of code heap with non-profiled methods (in bytes)") \
1521 range(0, SIZE_MAX) \
1522 \
1523 product_pd(size_t, ProfiledCodeHeapSize, \
1524 "Size of code heap with profiled methods (in bytes)") \
1525 range(0, SIZE_MAX) \
1526 \
1527 product_pd(size_t, NonNMethodCodeHeapSize, \
1528 "Size of code heap with non-nmethods (in bytes)") \
1529 constraint(VMPageSizeConstraintFunc, AtParse) \
1530 \
1531 product(size_t, HotCodeHeapSize, 0, EXPERIMENTAL, \
1532 "Size of code heap with predicted hot methods (in bytes)") \
1533 range(0, SIZE_MAX) \
1534 \
1535 product_pd(size_t, CodeCacheExpansionSize, \
1536 "Code cache expansion size (in bytes)") \
1537 range(32*K, SIZE_MAX) \
1538 \
1539 product_pd(size_t, CodeCacheMinBlockLength, DIAGNOSTIC, \
1540 "Minimum number of segments in a code cache block") \
1541 range(1, 100) \
1542 \
1543 develop(bool, ExitOnFullCodeCache, false, \
1544 "Exit the VM if we fill the code cache") \
1545 \
1546 product(bool, UseCodeCacheFlushing, true, \
1547 "Remove cold/old nmethods from the code cache") \
1548 \
1549 product(double, SweeperThreshold, 15.0, \
1550 "Threshold when a code cache unloading GC is invoked." \
1551 "Value is percentage of ReservedCodeCacheSize.") \
1552 range(0.0, 100.0) \
1553 \
1554 product(uintx, StartAggressiveSweepingAt, 10, \
1555 "Start aggressive sweeping if less than X[%] of the total code cache is free.")\
1556 range(0, 100) \
1557 \
1558 product(bool, NMethodRelocation, false, EXPERIMENTAL, \
1559 "Enables use of experimental function nmethod::relocate()") \
1560 \
1561 /* interpreter debugging */ \
1562 develop(intx, BinarySwitchThreshold, 5, \
1563 "Minimal number of lookupswitch entries for rewriting to binary " \
1564 "switch") \
1565 \
1566 develop(uintx, StopInterpreterAt, 0, \
1567 "Stop interpreter execution at specified bytecode number") \
1568 \
1569 develop(uintx, TraceBytecodesAt, 0, \
1570 "Trace bytecodes starting with specified bytecode number") \
1571 \
1572 develop(uintx, TraceBytecodesStopAt, 0, \
1573 "Stop bytecode tracing at the specified bytecode number") \
1574 \
1575 /* Priorities */ \
1576 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1577 \
1578 product(int, ThreadPriorityPolicy, 0, \
1579 "0 : Normal. "\
1580 " VM chooses priorities that are appropriate for normal "\
1581 " applications. "\
1582 " On Windows applications are allowed to use higher native "\
1583 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1584 " not use the highest possible native priority, "\
1585 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1586 " system threads. On Linux thread priorities are ignored "\
1587 " because the OS does not support static priority in "\
1588 " SCHED_OTHER scheduling class which is the only choice for "\
1589 " non-root, non-realtime applications. "\
1590 "1 : Aggressive. "\
1591 " Java thread priorities map over to the entire range of "\
1592 " native thread priorities. Higher Java thread priorities map "\
1593 " to higher native thread priorities. This policy should be "\
1594 " used with care, as sometimes it can cause performance "\
1595 " degradation in the application and/or the entire system. On "\
1596 " Linux/BSD/macOS this policy requires root privilege or an "\
1597 " extended capability.") \
1598 range(0, 1) \
1599 \
1600 product(bool, ThreadPriorityVerbose, false, \
1601 "Print priority changes") \
1602 \
1603 product(int, CompilerThreadPriority, -1, \
1604 "The native priority at which compiler threads should run " \
1605 "(-1 means no change)") \
1606 range(min_jint, max_jint) \
1607 \
1608 product(int, VMThreadPriority, -1, \
1609 "The native priority at which the VM thread should run " \
1610 "(-1 means no change)") \
1611 range(min_jint, max_jint) \
1612 \
1613 product(int, JavaPriority1_To_OSPriority, -1, \
1614 "Map Java priorities to OS priorities") \
1615 range(min_jint, max_jint) \
1616 \
1617 product(int, JavaPriority2_To_OSPriority, -1, \
1618 "Map Java priorities to OS priorities") \
1619 range(min_jint, max_jint) \
1620 \
1621 product(int, JavaPriority3_To_OSPriority, -1, \
1622 "Map Java priorities to OS priorities") \
1623 range(min_jint, max_jint) \
1624 \
1625 product(int, JavaPriority4_To_OSPriority, -1, \
1626 "Map Java priorities to OS priorities") \
1627 range(min_jint, max_jint) \
1628 \
1629 product(int, JavaPriority5_To_OSPriority, -1, \
1630 "Map Java priorities to OS priorities") \
1631 range(min_jint, max_jint) \
1632 \
1633 product(int, JavaPriority6_To_OSPriority, -1, \
1634 "Map Java priorities to OS priorities") \
1635 range(min_jint, max_jint) \
1636 \
1637 product(int, JavaPriority7_To_OSPriority, -1, \
1638 "Map Java priorities to OS priorities") \
1639 range(min_jint, max_jint) \
1640 \
1641 product(int, JavaPriority8_To_OSPriority, -1, \
1642 "Map Java priorities to OS priorities") \
1643 range(min_jint, max_jint) \
1644 \
1645 product(int, JavaPriority9_To_OSPriority, -1, \
1646 "Map Java priorities to OS priorities") \
1647 range(min_jint, max_jint) \
1648 \
1649 product(int, JavaPriority10_To_OSPriority,-1, \
1650 "Map Java priorities to OS priorities") \
1651 range(min_jint, max_jint) \
1652 \
1653 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1654 "Java thread priority 10 maps to critical scheduling priority") \
1655 \
1656 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1657 "Compiler thread(s) run at critical scheduling priority") \
1658 \
1659 develop(intx, NewCodeParameter, 0, \
1660 "Testing Only: Create a dedicated integer parameter before " \
1661 "putback") \
1662 \
1663 /* new oopmap storage allocation */ \
1664 develop(int, MinOopMapAllocation, 8, \
1665 "Minimum number of OopMap entries in an OopMapSet") \
1666 range(0, max_jint) \
1667 \
1668 /* recompilation */ \
1669 product_pd(intx, CompileThreshold, \
1670 "number of interpreted method invocations before (re-)compiling") \
1671 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1672 \
1673 product_pd(bool, TieredCompilation, \
1674 "Enable tiered compilation") \
1675 \
1676 /* Properties for Java libraries */ \
1677 \
1678 product(uint64_t, MaxDirectMemorySize, 0, \
1679 "Maximum total size of NIO direct-buffer allocations. " \
1680 "Ignored if not explicitly set.") \
1681 range(0, max_jlong) \
1682 \
1683 /* Flags used for temporary code during development */ \
1684 \
1685 product(bool, UseNewCode, false, DIAGNOSTIC, \
1686 "Testing Only: Use the new version while testing") \
1687 \
1688 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1689 "Testing Only: Use the new version while testing") \
1690 \
1691 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1692 "Testing Only: Use the new version while testing") \
1693 \
1694 develop(bool, UseDebuggerErgo, false, \
1695 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1696 "Turns on the other UseDebuggerErgo* flags") \
1697 \
1698 develop(bool, UseDebuggerErgo1, false, \
1699 "Debugging Only: Enable workarounds for debugger induced " \
1700 "os::processor_id() >= os::processor_count() problems") \
1701 \
1702 develop(bool, UseDebuggerErgo2, false, \
1703 "Debugging Only: Limit the number of spawned JVM threads") \
1704 \
1705 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1706 "Enable JVMTI asserts related to stack depth checks") \
1707 \
1708 /* flags for performance data collection */ \
1709 \
1710 product(bool, UsePerfData, true, \
1711 "Flag to disable jvmstat instrumentation for performance testing "\
1712 "and problem isolation purposes") \
1713 \
1714 product(bool, PerfDataSaveToFile, false, \
1715 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1716 \
1717 product(ccstr, PerfDataSaveFile, nullptr, \
1718 "Save PerfData memory to the specified absolute pathname. " \
1719 "The string %p in the file name (if present) " \
1720 "will be replaced by pid") \
1721 \
1722 product(bool, PerfDisableSharedMem, false, \
1723 "Store performance data in standard memory") \
1724 \
1725 product(int, PerfDataMemorySize, 32*K, \
1726 "Size of performance data memory region. Will be rounded " \
1727 "up to a multiple of the native os page size.") \
1728 range(128, 32*64*K) \
1729 \
1730 product(int, PerfMaxStringConstLength, 1024, \
1731 "Maximum PerfStringConstant string length before truncation") \
1732 range(32, 32*K) \
1733 \
1734 product(bool, PerfAllowAtExitRegistration, false, \
1735 "Allow registration of atexit() methods") \
1736 \
1737 product(bool, PerfBypassFileSystemCheck, false, \
1738 "Bypass Win32 file system criteria checks (Windows Only)") \
1739 \
1740 product(int, UnguardOnExecutionViolation, 0, \
1741 "Unguard page and retry on no-execute fault (Win32 only) " \
1742 "0=off, 1=conservative, 2=aggressive") \
1743 range(0, 2) \
1744 \
1745 /* Serviceability Support */ \
1746 \
1747 product(bool, ManagementServer, false, \
1748 "Create JMX Management Server") \
1749 \
1750 product(bool, DisableAttachMechanism, false, \
1751 "Disable mechanism that allows tools to attach to this VM") \
1752 \
1753 product(bool, StartAttachListener, false, \
1754 "Always start Attach Listener at VM startup") \
1755 \
1756 product(bool, EnableDynamicAgentLoading, true, \
1757 "Allow tools to load agents with the attach mechanism") \
1758 \
1759 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1760 "Print java.util.concurrent locks in thread dump") \
1761 \
1762 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1763 "Print generated stub code for method handles") \
1764 \
1765 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1766 "perform extra checks when constructing method handles") \
1767 \
1768 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1769 "show method handle implementation frames (usually hidden)") \
1770 \
1771 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1772 "show virtual threads' carrier frames in exceptions") \
1773 \
1774 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1775 "trust final non-static declarations for constant folding") \
1776 \
1777 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1778 "Optimize loads from stable fields (marked w/ @Stable)") \
1779 \
1780 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1781 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1782 "resolved before the bootstrap method is called; 1: when a BSM " \
1783 "that may accept a BootstrapCallInfo is detected, use that API " \
1784 "to pass BSM arguments, which allows the BSM to delay their " \
1785 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1786 "via that API, instead of with the eagerly-resolved array.") \
1787 \
1788 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1789 "Causes the VM to pause at startup time and wait for the pause " \
1790 "file to be removed (default: ./vm.paused.<pid>)") \
1791 \
1792 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1793 "The file to create and for whose removal to await when pausing " \
1794 "at startup. (default: ./vm.paused.<pid>)") \
1795 \
1796 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1797 "Pause and wait for keypress on exit if a debugger is attached") \
1798 \
1799 product(bool, DTraceMethodProbes, false, \
1800 "Enable dtrace tool probes for method-entry and method-exit") \
1801 \
1802 product(bool, DTraceAllocProbes, false, \
1803 "Enable dtrace tool probes for object allocation") \
1804 \
1805 product(bool, DTraceMonitorProbes, false, \
1806 "Enable dtrace tool probes for monitor events") \
1807 \
1808 product(bool, RelaxAccessControlCheck, false, \
1809 "Relax the access control checks in the verifier") \
1810 \
1811 product(uintx, StringTableSize, defaultStringTableSize, \
1812 "Number of buckets in the interned String table " \
1813 "(will be rounded to nearest higher power of 2)") \
1814 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1815 \
1816 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1817 "Number of buckets in the JVM internal Symbol table") \
1818 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1819 \
1820 product(bool, UseStringDeduplication, false, \
1821 "Use string deduplication") \
1822 \
1823 product(uint, StringDeduplicationAgeThreshold, 3, \
1824 "A string must reach this age (or be promoted to an old region) " \
1825 "to be considered for deduplication") \
1826 range(1, markWord::max_age) \
1827 \
1828 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1829 "Approximate initial number of buckets in the table") \
1830 range(1, 1 * G) \
1831 \
1832 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1833 "Entries per bucket above which the table should be expanded") \
1834 range(0.1, 1000.0) \
1835 \
1836 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1837 "Entries per bucket below which the table should be shrunk") \
1838 range(0.01, 100.0) \
1839 \
1840 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1841 "Desired entries per bucket when resizing the table") \
1842 range(0.01, 1000.0) \
1843 \
1844 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1845 "Minimum number of dead table entries for cleaning the table") \
1846 \
1847 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1848 "Minimum percentage of dead table entries for cleaning the table") \
1849 range(1, 100) \
1850 \
1851 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1852 "Force more frequent table resizing") \
1853 \
1854 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1855 "Seed for the table hashing function; 0 requests computed seed") \
1856 \
1857 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1858 "Enable internal testing APIs") \
1859 \
1860 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1861 "Use unaligned memory accesses in Unsafe") \
1862 \
1863 product_pd(bool, PreserveFramePointer, \
1864 "Use the FP register for holding the frame pointer " \
1865 "and not as a general purpose register.") \
1866 \
1867 product(size_t, AsyncLogBufferSize, 2*M, \
1868 "Memory budget (in bytes) for the buffer of Asynchronous " \
1869 "Logging (-Xlog:async).") \
1870 range(DEBUG_ONLY(192) NOT_DEBUG(100*K), 50*M) \
1871 \
1872 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1873 "When a class C is loaded, check that " \
1874 "(1) all intrinsics defined by the VM for class C are present "\
1875 "in the loaded class file and are marked with the " \
1876 "@IntrinsicCandidate annotation, that " \
1877 "(2) there is an intrinsic registered for all loaded methods " \
1878 "that are annotated with the @IntrinsicCandidate annotation, " \
1879 "and that " \
1880 "(3) no orphan methods exist for class C (i.e., methods for " \
1881 "which the VM declares an intrinsic but that are not declared "\
1882 "in the loaded class C. " \
1883 "Check (3) is available only in debug builds.") \
1884 \
1885 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1886 "Threshold small size (in bytes) for clearing arrays. " \
1887 "Anything this size or smaller may get converted to discrete " \
1888 "scalar stores.") \
1889 range(0, max_intx) \
1890 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1891 \
1892 product(ccstr, AllocateHeapAt, nullptr, \
1893 "Path to the directory where a temporary file will be created " \
1894 "to use as the backing store for Java Heap.") \
1895 \
1896 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1897 "Enable VM continuations support") \
1898 \
1899 develop(bool, LoomDeoptAfterThaw, false, \
1900 "Deopt stack after thaw") \
1901 \
1902 develop(bool, LoomVerifyAfterThaw, false, \
1903 "Verify stack after thaw") \
1904 \
1905 develop(bool, VerifyContinuations, false, \
1906 "Verify continuation consistency") \
1907 \
1908 develop(bool, UseContinuationFastPath, true, \
1909 "Use fast-path frame walking in continuations") \
1910 \
1911 develop(bool, ForceSingleFrameThaw, false, \
1912 "Force thawing one frame at a time") \
1913 \
1914 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1915 "Run periodic metaspace verifications (0 - none, " \
1916 "1 - always, >1 every nth interval)") \
1917 \
1918 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1919 "On internal errors, include registers in error report.") \
1920 \
1921 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1922 "leverage profiling for table/lookup switch") \
1923 \
1924 develop(bool, TraceMemoryWriteback, false, \
1925 "Trace memory writeback operations") \
1926 \
1927 JFR_ONLY(product(bool, FlightRecorder, false, \
1928 "(Deprecated) Enable Flight Recorder")) \
1929 \
1930 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1931 "Flight Recorder options")) \
1932 \
1933 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1934 "Start flight recording with options")) \
1935 \
1936 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1937 "Use platform unstable time where supported for timestamps only") \
1938 \
1939 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1940 "Make nmethod barriers deoptimise a lot.") \
1941 \
1942 develop(bool, VerifyCrossModifyFence, \
1943 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1944 "Mark all threads after a safepoint, and clear on a modify " \
1945 "fence. Add cleanliness checks.") \
1946 \
1947 product(bool, UseObjectMonitorTable, true, DIAGNOSTIC, \
1948 "Use a table to record inflated monitors rather than the first " \
1949 "word of the object.") \
1950 \
1951 product(int, FastLockingSpins, 8, DIAGNOSTIC, \
1952 "Specifies the number of times fast locking will attempt to " \
1953 "CAS the markWord before inflating. Between each CAS it will " \
1954 "spin for exponentially more time, resulting in a total number " \
1955 "of spins on the order of O(2^value)") \
1956 range(1, 30) \
1957 \
1958 product(uint, TrimNativeHeapInterval, 0, \
1959 "Interval, in ms, at which the JVM will trim the native heap if " \
1960 "the platform supports that. Lower values will reclaim memory " \
1961 "more eagerly at the cost of higher overhead. A value of 0 " \
1962 "(default) disables native heap trimming.") \
1963 range(0, UINT_MAX) \
1964 \
1965 develop(bool, SimulateFullAddressSpace, false, \
1966 "Simulates a very populated, fragmented address space; no " \
1967 "targeted reservations will succeed.") \
1968 \
1969 product(bool, ProfileExceptionHandlers, true, \
1970 "Profile exception handlers") \
1971 \
1972 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
1973 "Unconditionally record nmethod dependencies on class " \
1974 "rewriting/transformation independently of the JVMTI " \
1975 "can_{retransform/redefine}_classes capabilities.") \
1976 \
1977 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
1978 "Use secondary supers cache during subtype checks.") \
1979 \
1980 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
1981 "Use hash table to lookup secondary supers.") \
1982 \
1983 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
1984 "Check that linear and hashed secondary lookups return the same result.") \
1985 \
1986 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
1987 "Use a terrible hash function in order to generate many collisions.") \
1988 \
1989 product(bool, UseThreadsLockThrottleLock, true, DIAGNOSTIC, \
1990 "Use an extra lock during Thread start and exit to alleviate" \
1991 "contention on Threads_lock.") \
1992 \
1993 develop(uint, BinarySearchThreshold, 16, \
1994 "Minimal number of elements in a sorted collection to prefer" \
1995 "binary search over simple linear search." ) \
1996 \
1997
1998 // end of RUNTIME_FLAGS
1999
2000 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2001 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2002 DECLARE_FLAGS(RUNTIME_FLAGS)
2003 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2004
2005 #endif // SHARE_RUNTIME_GLOBALS_HPP