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 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
24
25 #ifndef SHARE_RUNTIME_GLOBALS_HPP
26 #define SHARE_RUNTIME_GLOBALS_HPP
27
28 #include "compiler/compiler_globals_pd.hpp"
29 #include "runtime/globals_shared.hpp"
30 #include "utilities/align.hpp"
31 #include "utilities/globalDefinitions.hpp"
32 #include "utilities/macros.hpp"
33 #include CPU_HEADER(globals)
34 #include OS_HEADER(globals)
35 #include OS_CPU_HEADER(globals)
36
37 // develop flags are settable / visible only during development and are constant in the PRODUCT version
38 // product flags are always settable / visible
39 // develop_pd/product_pd flags are the same as develop/product, except that their default values
40 // are specified in platform-dependent header files.
41
42 // Flags must be declared with the following number of parameters:
43 // non-pd flags:
44 // (type, name, default_value, doc), or
45 // (type, name, default_value, extra_attrs, doc)
46 // pd flags:
47 // (type, name, doc), or
48 // (type, name, extra_attrs, doc)
49
50 // A flag must be declared with one of the following types:
51 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t.
52 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used
53 // only in this file, because the macrology requires single-token type names.
54
55 // The optional extra_attrs parameter may have one of the following values:
56 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used
57 // only with product/product_pd flags.
58 //
59 // DIAGNOSTIC options are not meant for VM tuning or for product modes.
60 // They are to be used for VM quality assurance or field diagnosis
61 // of VM bugs. They are hidden so that users will not be encouraged to
62 // try them as if they were VM ordinary execution options. However, they
63 // are available in the product version of the VM. Under instruction
64 // from support engineers, VM customers can turn them on to collect
65 // diagnostic information about VM problems. To use a VM diagnostic
66 // option, you must first specify +UnlockDiagnosticVMOptions.
67 // (This master switch also affects the behavior of -Xprintflags.)
68 //
69 // EXPERIMENTAL flags are in support of features that may not be
70 // an officially supported part of a product, but may be available
71 // for experimenting with. They could, for example, be performance
72 // features that may not have undergone full or rigorous QA, but which may
73 // help performance in some cases and released for experimentation
74 // by the community of users and developers. This flag also allows one to
75 // be able to build a fully supported product that nonetheless also
76 // ships with some unsupported, lightly tested, experimental features.
77 // Refer to the documentation of any products using this code for details
78 // on support and fitness for production.
79 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
80 // UnlockExperimentalVMOptions flag, which allows the control and
81 // modification of the experimental flags.
82 //
83 // Nota bene: neither diagnostic nor experimental options should be used casually,
84 // Refer to the documentation of any products using this code for details.
85 //
86 // MANAGEABLE flags are writeable external product flags.
87 // They are dynamically writeable through the JDK management interface
88 // (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole.
89 // These flags are external exported interface (see CSR). The list of
90 // manageable flags can be queried programmatically through the management
91 // interface.
92 //
93 // A flag can be made as "manageable" only if
94 // - the flag is defined in a CSR request as an external exported interface.
95 // - the VM implementation supports dynamic setting of the flag.
96 // This implies that the VM must *always* query the flag variable
97 // and not reuse state related to the flag state at any given time.
98 // - you want the flag to be queried programmatically by the customers.
99 //
100
101 //
102 // range is a macro that will expand to min and max arguments for range
103 // checking code if provided - see jvmFlagLimit.hpp
104 //
105 // constraint is a macro that will expand to custom function call
106 // for constraint checking if provided - see jvmFlagLimit.hpp
107
108 // Default and minimum StringTable and SymbolTable size values
109 // Must be powers of 2
110 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536);
111 const size_t minimumStringTableSize = 128;
112 const size_t defaultSymbolTableSize = 32768; // 2^15
113 const size_t minimumSymbolTableSize = 1024;
114
115 #ifdef _LP64
116 #define LP64_RUNTIME_FLAGS(develop, \
117 develop_pd, \
118 product, \
119 product_pd, \
120 range, \
121 constraint) \
122 \
123 product(bool, UseCompressedOops, false, \
124 "Use 32-bit object references in 64-bit VM. " \
125 "lp64_product means flag is always constant in 32 bit VM") \
126 \
127 product(bool, UseCompactObjectHeaders, false, \
128 "Use compact 64-bit object headers in 64-bit VM") \
129 \
130 product(int, ObjectAlignmentInBytes, 8, \
131 "Default object alignment in bytes, 8 is minimum") \
132 range(8, 256) \
133 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
134
135 #else
136 // !_LP64
137
138 #define LP64_RUNTIME_FLAGS(develop, \
139 develop_pd, \
140 product, \
141 product_pd, \
142 range, \
143 constraint)
144 const bool UseCompressedOops = false;
145 const bool UseCompactObjectHeaders = false;
146 const int ObjectAlignmentInBytes = 8;
147
148 #endif // _LP64
149
150 // Default value for PrintAssemblyOptions, set via --with-print-assembly-options.
151 #ifndef DEFAULT_PRINT_ASSEMBLY_OPTIONS
152 #define DEFAULT_PRINT_ASSEMBLY_OPTIONS nullptr
153 #endif
154
155 #define RUNTIME_FLAGS(develop, \
156 develop_pd, \
157 product, \
158 product_pd, \
159 range, \
160 constraint) \
161 \
162 develop(bool, CheckCompressedOops, true, \
163 "Generate checks in encoding/decoding code in debug VM") \
164 \
165 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
166 "Heap allocation steps through preferred address regions to find" \
167 " where it can allocate the heap. Number of steps to take per " \
168 "region.") \
169 range(1, max_uintx) \
170 \
171 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
172 "If nonzero set a timeout in milliseconds for handshakes") \
173 \
174 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
175 "Force safe construction, as if all fields are final.") \
176 \
177 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
178 "Enable normal processing of flags relating to field diagnostics")\
179 \
180 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
181 "Enable normal processing of flags relating to experimental " \
182 "features") \
183 \
184 product(bool, JavaMonitorsInStackTrace, true, \
185 "Print information about Java monitor locks when the stacks are " \
186 "dumped") \
187 \
188 product_pd(bool, UseLargePages, \
189 "Use large page memory") \
190 \
191 product_pd(bool, UseLargePagesIndividualAllocation, \
192 "Allocate large pages individually for better affinity") \
193 \
194 develop(bool, LargePagesIndividualAllocationInjectError, false, \
195 "Fail large pages individual allocation") \
196 \
197 product(bool, UseNUMA, false, \
198 "Use NUMA if available") \
199 \
200 product(bool, UseNUMAInterleaving, false, \
201 "Interleave memory across NUMA nodes if available") \
202 \
203 product(size_t, NUMAInterleaveGranularity, 2*M, \
204 "Granularity to use for NUMA interleaving on Windows OS") \
205 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
206 \
207 product(bool, NUMAStats, false, \
208 "Print NUMA stats in detailed heap information") \
209 \
210 product(bool, UseAES, false, \
211 "Control whether AES instructions are used when available") \
212 \
213 product(bool, UseFMA, false, \
214 "Control whether FMA instructions are used when available") \
215 \
216 product(bool, UseSHA, false, \
217 "Control whether SHA instructions are used when available") \
218 \
219 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
220 "Use intrinsics for GHASH versions of crypto") \
221 \
222 product(bool, UseBASE64Intrinsics, false, \
223 "Use intrinsics for java.util.Base64") \
224 \
225 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
226 "Use intrinsics for sun.security.util.math.intpoly") \
227 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
228 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
229 \
230 product(size_t, LargePageSizeInBytes, 0, \
231 "Maximum large page size used (0 will use the default large " \
232 "page size for the environment as the maximum) " \
233 "(must be a power of 2)") \
234 range(0, max_uintx) \
235 constraint(LargePageSizeInBytesConstraintFunc, AtParse) \
236 \
237 product(size_t, LargePageHeapSizeThreshold, 128*M, \
238 "Use large pages if maximum heap is at least this big") \
239 range(0, max_uintx) \
240 \
241 product(bool, ForceTimeHighResolution, false, \
242 "Using high time resolution (for Win32 only)") \
243 \
244 develop(bool, TracePcPatching, false, \
245 "Trace usage of frame::patch_pc") \
246 \
247 develop(bool, TraceRelocator, false, \
248 "Trace the bytecode relocator") \
249 \
250 \
251 product(bool, SafepointALot, false, DIAGNOSTIC, \
252 "Generate a lot of safepoints. This works with " \
253 "GuaranteedSafepointInterval") \
254 \
255 product(bool, HandshakeALot, false, DIAGNOSTIC, \
256 "Generate a lot of handshakes. This works with " \
257 "GuaranteedSafepointInterval") \
258 \
259 product_pd(bool, BackgroundCompilation, \
260 "A thread requesting compilation is not blocked during " \
261 "compilation") \
262 \
263 product(bool, MethodFlushing, true, \
264 "Reclamation of compiled methods") \
265 \
266 develop(bool, VerifyStack, false, \
267 "Verify stack of each thread when it is entering a runtime call") \
268 \
269 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
270 "Make all non code cache addresses to be unreachable by " \
271 "forcing use of 64bit literal fixups") \
272 \
273 develop(bool, TraceDerivedPointers, false, \
274 "Trace traversal of derived pointers on stack") \
275 \
276 develop(bool, TraceCodeBlobStacks, false, \
277 "Trace stack-walk of codeblobs") \
278 \
279 develop(bool, PrintRewrites, false, \
280 "Print methods that are being rewritten") \
281 \
282 product(bool, UseInlineCaches, true, \
283 "Use Inline Caches for virtual calls ") \
284 \
285 develop(bool, VerifyInlineCaches, true, \
286 "Verify Inline Caches") \
287 \
288 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
289 "Inline arraycopy native that is known to be part of " \
290 "base library DLL") \
291 \
292 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
293 "Inline Object::hashCode() native that is known to be part " \
294 "of base library DLL") \
295 \
296 product(bool, InlineNatives, true, DIAGNOSTIC, \
297 "Inline natives that are known to be part of base library DLL") \
298 \
299 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
300 "Inline SinD, CosD, etc.") \
301 \
302 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
303 "Inline Class.isInstance, etc") \
304 \
305 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
306 "Inline Thread.currentThread, etc") \
307 \
308 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
309 "Inline memory ops (native methods) from Unsafe") \
310 \
311 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
312 "Use intrinsics for AES versions of crypto") \
313 \
314 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
315 "Use intrinsics for the paralleled version of AES/CTR crypto") \
316 \
317 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
318 "Use intrinsics for the vectorized version of ChaCha20") \
319 \
320 product(bool, UseKyberIntrinsics, false, DIAGNOSTIC, \
321 "Use intrinsics for the vectorized version of Kyber") \
322 \
323 product(bool, UseDilithiumIntrinsics, false, DIAGNOSTIC, \
324 "Use intrinsics for the vectorized version of Dilithium") \
325 \
326 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
327 "Use intrinsics for MD5 crypto hash function") \
328 \
329 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
330 "Use intrinsics for SHA-1 crypto hash function. " \
331 "Requires that UseSHA is enabled.") \
332 \
333 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
334 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
335 "Requires that UseSHA is enabled.") \
336 \
337 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
338 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
339 "Requires that UseSHA is enabled.") \
340 \
341 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
342 "Use intrinsics for SHA3 crypto hash function. " \
343 "Requires that UseSHA is enabled.") \
344 \
345 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
346 "use intrinsics for java.util.zip.CRC32") \
347 \
348 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
349 "use intrinsics for java.util.zip.CRC32C") \
350 \
351 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
352 "use intrinsics for java.util.zip.Adler32") \
353 \
354 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
355 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
356 \
357 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
358 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
359 \
360 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
361 "Enables intrinsification of Math.copySign") \
362 \
363 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
364 "Enables intrinsification of Math.signum") \
365 \
366 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
367 "Use Compiler thread for compiler's stubs generation") \
368 \
369 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
370 "do not expand intrinsics whose (internal) names appear here") \
371 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
372 \
373 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
374 "Control intrinsics using a list of +/- (internal) names, " \
375 "separated by commas") \
376 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
377 \
378 develop(bool, TraceCallFixup, false, \
379 "Trace all call fixups") \
380 \
381 develop(bool, DeoptimizeALot, false, \
382 "Deoptimize at every exit from the runtime system") \
383 \
384 develop(ccstrlist, DeoptimizeOnlyAt, "", \
385 "A comma separated list of bcis to deoptimize at") \
386 \
387 develop(bool, DeoptimizeRandom, false, \
388 "Deoptimize random frames on random exit from the runtime system")\
389 \
390 develop(bool, ZombieALot, false, \
391 "Create non-entrant nmethods at exit from the runtime system") \
392 \
393 develop(bool, WalkStackALot, false, \
394 "Trace stack (no print) at every exit from the runtime system") \
395 \
396 develop(bool, DeoptimizeObjectsALot, false, \
397 "For testing purposes concurrent threads revert optimizations " \
398 "based on escape analysis at intervals given with " \
399 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
400 "with DeoptimizeObjectsALotThreadCountSingle and " \
401 "DeoptimizeObjectsALotThreadCountAll.") \
402 \
403 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
404 "Interval for DeoptimizeObjectsALot.") \
405 range(0, max_jlong) \
406 \
407 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
408 "The number of threads that revert optimizations based on " \
409 "escape analysis for a single thread if DeoptimizeObjectsALot " \
410 "is enabled. The target thread is selected round robin." ) \
411 range(0, max_jint) \
412 \
413 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
414 "The number of threads that revert optimizations based on " \
415 "escape analysis for all threads if DeoptimizeObjectsALot " \
416 "is enabled." ) \
417 range(0, max_jint) \
418 \
419 develop(bool, VerifyLastFrame, false, \
420 "Verify oops on last frame on entry to VM") \
421 \
422 product(bool, SafepointTimeout, false, \
423 "Time out and warn or fail after SafepointTimeoutDelay " \
424 "milliseconds if failed to reach safepoint") \
425 \
426 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
427 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
428 \
429 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
430 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
431 range(0, max_jlong) \
432 \
433 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
434 "Abort upon failure to complete VM operation promptly") \
435 \
436 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
437 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
438 range(0, max_intx) \
439 \
440 product(bool, MaxFDLimit, true, \
441 "Bump the number of file descriptors to maximum (Unix only)") \
442 \
443 product(bool, LogEvents, true, DIAGNOSTIC, \
444 "Enable the various ring buffer event logs") \
445 \
446 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
447 "Number of ring buffer event logs") \
448 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
449 \
450 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
451 "Enable the Java bytecode verifier for remote classes") \
452 \
453 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
454 "Enable the Java bytecode verifier for local classes") \
455 \
456 develop(bool, VerifyStackAtCalls, false, \
457 "Verify that the stack pointer is unchanged after calls") \
458 \
459 develop(bool, TraceJavaAssertions, false, \
460 "Trace java language assertions") \
461 \
462 develop(bool, VerifyCodeCache, false, \
463 "Verify code cache on memory allocation/deallocation") \
464 \
465 develop(bool, ZapResourceArea, trueInDebug, \
466 "Zap freed resource/arena space") \
467 \
468 develop(bool, ZapVMHandleArea, trueInDebug, \
469 "Zap freed VM handle space") \
470 \
471 develop(bool, ZapStackSegments, trueInDebug, \
472 "Zap allocated/freed stack segments") \
473 \
474 develop(bool, ZapUnusedHeapArea, trueInDebug, \
475 "Zap unused heap space") \
476 \
477 develop(bool, ZapFillerObjects, trueInDebug, \
478 "Zap filler objects") \
479 \
480 develop(bool, ZapCHeap, trueInDebug, \
481 "Zap allocated/freed C heap space") \
482 \
483 develop(bool, ZapTLAB, trueInDebug, \
484 "Zap allocated TLABs") \
485 develop(bool, TestingAsyncLoggingDeathTest, false, \
486 "Recursive logging death test") \
487 develop(bool, TestingAsyncLoggingDeathTestNoCrash, false, \
488 "Recursive logging death test (no crash)") \
489 \
490 product(bool, ExecutingUnitTests, false, \
491 "Whether the JVM is running unit tests or not") \
492 \
493 develop(uint, ErrorHandlerTest, 0, \
494 "If > 0, provokes an error after VM initialization; the value " \
495 "determines which error to provoke. See controlled_crash() " \
496 "in vmError.cpp.") \
497 range(0, 18) \
498 \
499 develop(uint, TestCrashInErrorHandler, 0, \
500 "If > 0, provokes an error inside VM error handler (a secondary " \
501 "crash). see controlled_crash() in vmError.cpp") \
502 range(0, 17) \
503 \
504 develop(bool, TestSafeFetchInErrorHandler, false , \
505 "If true, tests SafeFetch inside error handler.") \
506 \
507 develop(bool, TestUnresponsiveErrorHandler, false, \
508 "If true, simulates an unresponsive error handler.") \
509 \
510 develop(bool, Verbose, false, \
511 "Print additional debugging information from other modes") \
512 \
513 develop(bool, PrintMiscellaneous, false, \
514 "Print uncategorized debugging information (requires +Verbose)") \
515 \
516 develop(bool, WizardMode, false, \
517 "Print much more debugging information") \
518 \
519 product(bool, ShowMessageBoxOnError, false, \
520 "Keep process alive on VM fatal error") \
521 \
522 product(bool, CreateCoredumpOnCrash, true, \
523 "Create core/mini dump on VM fatal error") \
524 \
525 product(uint64_t, ErrorLogTimeout, 2 * 60, \
526 "Timeout, in seconds, to limit the time spent on writing an " \
527 "error log in case of a crash.") \
528 range(0, (uint64_t)max_jlong/1000) \
529 \
530 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
531 "If enabled, show details on secondary crashes in the error log") \
532 \
533 develop(intx, TraceDwarfLevel, 0, \
534 "Debug levels for the dwarf parser") \
535 range(0, 4) \
536 \
537 product(bool, SuppressFatalErrorMessage, false, \
538 "Report NO fatal error message (avoid deadlock)") \
539 \
540 product(ccstrlist, OnError, "", \
541 "Run user-defined commands on fatal error; see VMError.cpp " \
542 "for examples") \
543 \
544 product(ccstrlist, OnOutOfMemoryError, "", \
545 "Run user-defined commands on first java.lang.OutOfMemoryError " \
546 "thrown from JVM") \
547 \
548 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
549 "Dump heap to file before any major stop-the-world GC " \
550 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
551 \
552 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
553 "Dump heap to file after any major stop-the-world GC " \
554 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
555 \
556 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
557 "Limit the number of heap dumps triggered by " \
558 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
559 "(0 means no limit)") \
560 \
561 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
562 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
563 "from JVM " \
564 "(also see HeapDumpPath, HeapDumpGzipLevel)") \
565 \
566 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
567 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
568 "or HeapDumpAfterFullGC is on, the path (filename or " \
569 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
570 "in the working directory)") \
571 \
572 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
573 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
574 "or HeapDumpAfterFullGC is on, the gzip compression " \
575 "level of the dump file. 0 (the default) disables gzip " \
576 "compression. Otherwise the level must be between 1 and 9.") \
577 range(0, 9) \
578 \
579 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
580 "Native memory tracking options") \
581 \
582 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
583 "Print native memory tracking summary data if it is on") \
584 \
585 product(bool, LogCompilation, false, DIAGNOSTIC, \
586 "Log compilation activity in detail to LogFile") \
587 \
588 product(bool, PrintCompilation, false, \
589 "Print compilations") \
590 \
591 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
592 "Repeat compilation without installing code (number of times)") \
593 range(0, max_jint) \
594 \
595 product(bool, PrintExtendedThreadInfo, false, \
596 "Print more information in thread dump") \
597 \
598 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
599 "0: do not allow scavengable oops in the code cache; " \
600 "1: allow scavenging from the code cache; " \
601 "2: emit as many constants as the compiler can see") \
602 range(0, 2) \
603 \
604 product(bool, AlwaysRestoreFPU, false, \
605 "Restore the FPU control word after every JNI call (expensive)") \
606 \
607 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
608 "Print additional statistics per compilation") \
609 \
610 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
611 "Print code generated for i2c/c2i adapters") \
612 \
613 develop(bool, VerifyAdapterSharing, false, \
614 "Verify that the code for shared adapters is the equivalent") \
615 \
616 product(bool, PrintAssembly, false, DIAGNOSTIC, \
617 "Print assembly code (using external disassembler.so)") \
618 \
619 product(ccstr, PrintAssemblyOptions, DEFAULT_PRINT_ASSEMBLY_OPTIONS, \
620 DIAGNOSTIC, \
621 "Print options string passed to disassembler.so") \
622 \
623 develop(bool, PrintNMethodStatistics, false, \
624 "Print a summary statistic for the generated nmethods") \
625 \
626 product(bool, PrintNMethods, false, DIAGNOSTIC, \
627 "Print assembly code for nmethods when generated") \
628 \
629 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
630 "Print assembly code for native nmethods when generated") \
631 \
632 develop(bool, PrintDebugInfo, false, \
633 "Print debug information for all nmethods when generated") \
634 \
635 develop(bool, PrintRelocations, false, \
636 "Print relocation information for all nmethods when generated") \
637 \
638 develop(bool, PrintDependencies, false, \
639 "Print dependency information for all nmethods when generated") \
640 \
641 develop(bool, PrintExceptionHandlers, false, \
642 "Print exception handler tables for all nmethods when generated") \
643 \
644 develop(bool, StressCompiledExceptionHandlers, false, \
645 "Exercise compiled exception handlers") \
646 \
647 product(bool, DeoptimizeOnAllocationException, false, DIAGNOSTIC, \
648 "Deoptimize on exception during allocation instead of using the " \
649 "compiled exception handlers") \
650 \
651 develop(bool, InterceptOSException, false, \
652 "Start debugger when an implicit OS (e.g. null pointer) " \
653 "exception happens") \
654 \
655 product(bool, PrintCodeCache, false, \
656 "Print the code cache memory usage when exiting") \
657 \
658 develop(bool, PrintCodeCache2, false, \
659 "Print detailed usage information on the code cache when exiting")\
660 \
661 product(bool, PrintCodeCacheOnCompilation, false, \
662 "Print the code cache memory usage each time a method is " \
663 "compiled") \
664 \
665 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
666 "Print code heap usage statistics on exit and on full condition") \
667 \
668 product(bool, PrintStubCode, false, DIAGNOSTIC, \
669 "Print generated stub code") \
670 \
671 product(bool, StackTraceInThrowable, true, \
672 "Collect backtrace in throwable when exception happens") \
673 \
674 product(bool, OmitStackTraceInFastThrow, true, \
675 "Omit backtraces for some 'hot' exceptions in optimized code") \
676 \
677 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
678 "Show exception messages from RuntimeExceptions that contain " \
679 "snippets of the failing code. Disable this to improve privacy.") \
680 \
681 product(bool, PrintWarnings, true, \
682 "Print JVM warnings to output stream") \
683 \
684 develop(bool, RegisterReferences, true, \
685 "Tell whether the VM should register soft/weak/final/phantom " \
686 "references") \
687 \
688 develop(bool, PrintCodeCacheExtension, false, \
689 "Print extension of code cache") \
690 \
691 product(bool, ClassUnloading, true, \
692 "Do unloading of classes") \
693 \
694 product(bool, ClassUnloadingWithConcurrentMark, true, \
695 "Do unloading of classes with a concurrent marking cycle") \
696 \
697 develop(bool, PrintSystemDictionaryAtExit, false, \
698 "Print the system dictionary at exit") \
699 \
700 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
701 "Print the class loader data graph at exit") \
702 \
703 product(bool, PrintVMInfoAtExit, false, DIAGNOSTIC, \
704 "Executes the VM.info diagnostic command at exit") \
705 \
706 product(bool, AllowParallelDefineClass, false, \
707 "Allow parallel defineClass requests for class loaders " \
708 "registering as parallel capable") \
709 \
710 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
711 "Disable the use of stack guard pages if the JVM is loaded " \
712 "on the primordial process thread") \
713 \
714 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
715 "Do JVMTI virtual thread mount/unmount transitions " \
716 "(disabling this flag implies no JVMTI events are posted)") \
717 \
718 /* notice: the max range value here is max_jint, not max_intx */ \
719 /* because of overflow issue */ \
720 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
721 "Async deflate idle monitors every so many milliseconds when " \
722 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
723 range(0, max_jint) \
724 \
725 /* notice: the max range value here is max_jint, not max_intx */ \
726 /* because of overflow issue */ \
727 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
728 "Async deflate idle monitors every so many milliseconds even " \
729 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
730 range(0, max_jint) \
731 \
732 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
733 "Used to estimate a variable ceiling based on number of threads " \
734 "for use with MonitorUsedDeflationThreshold (0 is off).") \
735 range(0, max_uintx) \
736 \
737 /* notice: the max range value here is max_jint, not max_intx */ \
738 /* because of overflow issue */ \
739 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
740 "The maximum number of monitors to deflate, unlink and delete " \
741 "at one time (minimum is 1024).") \
742 range(1024, max_jint) \
743 \
744 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
745 "The maximum number of monitors to unlink in one batch. ") \
746 range(1, max_jint) \
747 \
748 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
749 "Percentage of used monitors before triggering deflation (0 is " \
750 "off). The check is performed on AsyncDeflationInterval or " \
751 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
752 range(0, 100) \
753 \
754 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
755 "Max number of no progress async deflation attempts to tolerate " \
756 "before adjusting the in_use_list_ceiling up (0 is off).") \
757 range(0, max_uintx) \
758 \
759 product(intx, hashCode, 5, EXPERIMENTAL, \
760 "(Unstable) select hashCode generation algorithm") \
761 \
762 product(bool, ReduceSignalUsage, false, \
763 "Reduce the use of OS signals in Java and/or the VM") \
764 \
765 develop(bool, LoadLineNumberTables, true, \
766 "Tell whether the class file parser loads line number tables") \
767 \
768 develop(bool, LoadLocalVariableTables, true, \
769 "Tell whether the class file parser loads local variable tables") \
770 \
771 develop(bool, LoadLocalVariableTypeTables, true, \
772 "Tell whether the class file parser loads local variable type" \
773 "tables") \
774 \
775 product(bool, AllowUserSignalHandlers, false, \
776 "Application will install primary signal handlers for the JVM " \
777 "(Unix only)") \
778 \
779 product(bool, UseSignalChaining, true, \
780 "Use signal-chaining to invoke signal handlers installed " \
781 "by the application (Unix only)") \
782 \
783 product(bool, RestoreMXCSROnJNICalls, false, \
784 "Restore MXCSR when returning from JNI calls") \
785 \
786 product(bool, CheckJNICalls, false, \
787 "Verify all arguments to JNI calls") \
788 \
789 product(bool, UseFastJNIAccessors, true, \
790 "Use optimized versions of Get<Primitive>Field") \
791 \
792 product(intx, MaxJNILocalCapacity, 65536, \
793 "Maximum allowable local JNI handle capacity to " \
794 "EnsureLocalCapacity() and PushLocalFrame(), " \
795 "where <= 0 is unlimited, default: 65536") \
796 range(min_intx, max_intx) \
797 \
798 product(bool, EagerXrunInit, false, \
799 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
800 "but not all -Xrun libraries may support the state of the VM " \
801 "at this time") \
802 \
803 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
804 "Number of OutOfMemoryErrors preallocated with backtrace") \
805 range(0, 1024) \
806 \
807 product(bool, PrintFieldLayout, false, DIAGNOSTIC, \
808 "Print field layout for each class") \
809 \
810 product(bool, PrintInlineLayout, false, DIAGNOSTIC, \
811 "Print field layout for each value class or class containing " \
812 "inlined value fields") \
813 \
814 product(bool, PrintFlatArrayLayout, false, DIAGNOSTIC, \
815 "Print array layout for each flattened value array") \
816 \
817 product(bool, UseArrayFlattening, true, DIAGNOSTIC, \
818 "Allow the JVM to flatten arrays of concrete value objects " \
819 "when it determines it is possible and beneficial to do so") \
820 \
821 product(bool, UseFieldFlattening, true, DIAGNOSTIC, \
822 "Allow the JVM to inline the fields of concrete value objects " \
823 "when it determines it is possible and beneficial to do so") \
824 \
825 product(bool, UseNullableAtomicValueFlattening, true, DIAGNOSTIC, \
826 "Allow the JVM to flatten some nullable atomic values") \
827 \
828 product(bool, UseNullFreeNonAtomicValueFlattening, true, EXPERIMENTAL, \
829 "Allow the JVM to flatten some null-free non-atomic values") \
830 \
831 product(bool, UseNullFreeAtomicValueFlattening, true, EXPERIMENTAL, \
832 "Allow the JVM to flatten some null-free atomic values") \
833 \
834 product(bool, UseNullableNonAtomicValueFlattening, true, DIAGNOSTIC, \
835 "Allow the JVM to flatten some strict final non-static fields") \
836 \
837 product(intx, FlatArrayElementMaxOops, 4, DIAGNOSTIC, \
838 "Max number of embedded object references in a value container " \
839 "before no flattening attempts are made, <0 indicates no limit") \
840 \
841 product(uint, FlatteningBudget, 1024, EXPERIMENTAL, \
842 "Maximum size (in bytes) dedicated to flat fields in an instance")\
843 range(0, 1024 * 1024) \
844 develop(ccstrlist, PrintInlineKlassFields, "", \
845 "Print fields collected by InlineKlass::collect_fields") \
846 \
847 /* Need to limit the extent of the padding to reasonable size. */\
848 /* 8K is well beyond the reasonable HW cache line size, even with */\
849 /* aggressive prefetching, while still leaving the room for segregating */\
850 /* among the distinct pages. */\
851 product(int, ContendedPaddingWidth, 128, \
852 "How many bytes to pad the fields/classes marked @Contended with")\
853 range(0, 8192) \
854 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
855 \
856 product(bool, EnableContended, true, \
857 "Enable @Contended annotation support") \
858 \
859 product(bool, RestrictContended, true, \
860 "Restrict @Contended to trusted classes") \
861 \
862 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
863 "Detect and take action upon identifying synchronization on " \
864 "value based classes. Modes: " \
865 "0: off; " \
866 "1: exit with fatal error; " \
867 "2: log message to stdout. Output file can be specified with " \
868 " -Xlog:valuebasedclasses. If JFR is running it will " \
869 " also generate JFR events.") \
870 range(0, 2) \
871 \
872 product(bool, ExitOnOutOfMemoryError, false, \
873 "JVM exits on the first occurrence of an out-of-memory error " \
874 "thrown from JVM") \
875 \
876 product(bool, CrashOnOutOfMemoryError, false, \
877 "JVM aborts, producing an error log and core/mini dump, on the " \
878 "first occurrence of an out-of-memory error thrown from JVM") \
879 \
880 product(intx, UserThreadWaitAttemptsAtExit, 30, \
881 "The number of times to wait for user threads to stop executing " \
882 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
883 "The maximum number of waits is 1000, to wait at most 10 " \
884 "seconds.") \
885 range(0, 1000) \
886 \
887 /* tracing */ \
888 \
889 develop(bool, StressRewriter, false, \
890 "Stress linktime bytecode rewriting") \
891 \
892 product(ccstr, TraceJVMTI, nullptr, \
893 "Trace flags for JVMTI functions and events") \
894 \
895 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
896 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
897 "This option can change an EMCP method into an obsolete method " \
898 "and can affect tests that expect specific methods to be EMCP. " \
899 "This option should be used with caution.") \
900 \
901 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
902 "(Deprecated) Allow redefinition to add and delete private " \
903 "static or final methods for compatibility with old releases") \
904 \
905 develop(bool, TraceBytecodes, false, \
906 "Trace bytecode execution") \
907 \
908 develop(bool, TraceBytecodesTruncated, false, \
909 "Truncate non control-flow bytecode when tracing bytecode") \
910 \
911 develop(bool, VerifyDependencies, trueInDebug, \
912 "Exercise and verify the compilation dependency mechanism") \
913 \
914 develop(bool, TimeOopMap, false, \
915 "Time calls to GenerateOopMap::compute_map() in sum") \
916 \
917 develop(bool, GenerateOopMapALot, false, \
918 "Generate interpreter oopmaps at all safepoints") \
919 \
920 develop(bool, TraceFinalizerRegistration, false, \
921 "Trace registration of final references") \
922 \
923 product(bool, IgnoreEmptyClassPaths, false, \
924 "Ignore empty path elements in -classpath") \
925 \
926 product(bool, PrintHeapAtSIGBREAK, true, \
927 "Print heap layout in response to SIGBREAK") \
928 \
929 product(bool, PrintClassHistogram, false, MANAGEABLE, \
930 "Print a histogram of class instances") \
931 \
932 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
933 "The percentage of the used heap that the instances of a class " \
934 "must occupy for the class to generate a trace event") \
935 range(0.0, 100.0) \
936 \
937 /* JVMTI heap profiling */ \
938 \
939 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
940 "Verify memory system before JVMTI iteration") \
941 \
942 /* compiler */ \
943 \
944 /* notice: the max range value here is max_jint, not max_intx */ \
945 /* because of overflow issue */ \
946 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
947 "Number of compiler threads to run") \
948 range(0, max_jint) \
949 constraint(CICompilerCountConstraintFunc, AfterErgo) \
950 \
951 product(bool, UseDynamicNumberOfCompilerThreads, true, \
952 "Dynamically choose the number of parallel compiler threads") \
953 \
954 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
955 "Reduce the number of parallel compiler threads when they " \
956 "are not used") \
957 \
958 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
959 "Trace creation and removal of compiler threads") \
960 \
961 product(ccstr, LogClassLoadingCauseFor, nullptr, \
962 "Apply -Xlog:class+load+cause* to classes whose fully " \
963 "qualified name contains this string (\"*\" matches " \
964 "any class).") \
965 \
966 develop(bool, InjectCompilerCreationFailure, false, \
967 "Inject thread creation failures for " \
968 "UseDynamicNumberOfCompilerThreads") \
969 \
970 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
971 "Generate code for implicit null checks") \
972 \
973 product_pd(bool, TrapBasedNullChecks, \
974 "Generate code for null checks that uses a cmp and trap " \
975 "instruction raising SIGTRAP. This is only used if an access to" \
976 "null (+offset) will not raise a SIGSEGV, i.e.," \
977 "ImplicitNullChecks don't work (PPC64).") \
978 \
979 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
980 "Enable Thread SMR Statistics") \
981 \
982 product(bool, Inline, true, \
983 "Enable inlining") \
984 \
985 product(bool, ClipInlining, true, \
986 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
987 \
988 develop(bool, UseCHA, true, \
989 "Enable CHA") \
990 \
991 product(bool, UseTypeProfile, true, \
992 "Check interpreter profile for historically monomorphic calls") \
993 \
994 product(bool, PrintInlining, false, DIAGNOSTIC, \
995 "Print inlining optimizations") \
996 \
997 product(bool, UsePopCountInstruction, false, \
998 "Use population count instruction") \
999 \
1000 develop(bool, TraceMethodReplacement, false, \
1001 "Print when methods are replaced do to recompilation") \
1002 \
1003 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
1004 "Minimum number of sweeper passes before an nmethod " \
1005 "can be flushed") \
1006 range(0, max_intx) \
1007 \
1008 develop(bool, StressCodeBuffers, false, \
1009 "Exercise code buffer expansion and other rare state changes") \
1010 \
1011 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
1012 "Generate extra debugging information for non-safepoints in " \
1013 "nmethods") \
1014 \
1015 product(bool, PrintVMOptions, false, \
1016 "Print flags that appeared on the command line") \
1017 \
1018 product(bool, IgnoreUnrecognizedVMOptions, false, \
1019 "Ignore unrecognized VM options") \
1020 \
1021 product(bool, PrintCommandLineFlags, false, \
1022 "Print flags specified on command line or set by ergonomics") \
1023 \
1024 product(bool, PrintFlagsInitial, false, \
1025 "Print all VM flags before argument processing and exit VM") \
1026 \
1027 product(bool, PrintFlagsFinal, false, \
1028 "Print all VM flags after argument and ergonomic processing") \
1029 \
1030 develop(bool, PrintFlagsWithComments, false, \
1031 "Print all VM flags with default values and descriptions and " \
1032 "exit") \
1033 \
1034 product(bool, PrintFlagsRanges, false, \
1035 "Print VM flags and their ranges") \
1036 \
1037 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1038 "Use a mutex to serialize output to tty and LogFile") \
1039 \
1040 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1041 "Display all VM output on the tty, independently of LogVMOutput") \
1042 \
1043 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1044 "Save VM output to LogFile") \
1045 \
1046 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1047 "If LogVMOutput or LogCompilation is on, save VM output to " \
1048 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1049 \
1050 product(ccstr, ErrorFile, nullptr, \
1051 "If an error occurs, save the error data to this file " \
1052 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1053 \
1054 product(bool, ExtensiveErrorReports, \
1055 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1056 "Error reports are more extensive.") \
1057 \
1058 product(bool, DisplayVMOutputToStderr, false, \
1059 "If DisplayVMOutput is true, display all VM output to stderr") \
1060 \
1061 product(bool, DisplayVMOutputToStdout, false, \
1062 "If DisplayVMOutput is true, display all VM output to stdout") \
1063 \
1064 product(bool, ErrorFileToStderr, false, \
1065 "If true, error data is printed to stderr instead of a file") \
1066 \
1067 product(bool, ErrorFileToStdout, false, \
1068 "If true, error data is printed to stdout instead of a file") \
1069 \
1070 product(bool, PrintStringTableStatistics, false, \
1071 "print statistics about the StringTable and SymbolTable") \
1072 \
1073 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1074 "verify StringTable contents at exit") \
1075 \
1076 develop(bool, PrintSymbolTableSizeHistogram, false, \
1077 "print histogram of the symbol table") \
1078 \
1079 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1080 "Call fatal if this exception is thrown. Example: " \
1081 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1082 \
1083 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1084 "Call fatal if the exception pointed by AbortVMOnException " \
1085 "has this message") \
1086 \
1087 develop(bool, DebugVtables, false, \
1088 "add debugging code to vtable dispatch") \
1089 \
1090 product(bool, RangeCheckElimination, true, \
1091 "Eliminate range checks") \
1092 \
1093 develop_pd(bool, UncommonNullCast, \
1094 "track occurrences of null in casts; adjust compiler tactics") \
1095 \
1096 develop(bool, TypeProfileCasts, true, \
1097 "treat casts like calls for purposes of type profiling") \
1098 \
1099 develop(bool, TraceLivenessGen, false, \
1100 "Trace the generation of liveness analysis information") \
1101 \
1102 develop(bool, TraceLivenessQuery, false, \
1103 "Trace queries of liveness analysis information") \
1104 \
1105 develop(bool, CollectIndexSetStatistics, false, \
1106 "Collect information about IndexSets") \
1107 \
1108 /* This value is later shifted left by up to LogBytesPerLong bits */\
1109 /* (to convert from element count to size in bytes), so we must ensure */\
1110 /* it does not overflow during the shift. */\
1111 develop(int, FastAllocateSizeLimit, 128*K, \
1112 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1113 "Inline allocations larger than this in doublewords must go slow")\
1114 range(0, (1 << (BitsPerInt - LogBytesPerLong - 1)) - 1) \
1115 \
1116 product_pd(bool, CompactStrings, \
1117 "Enable Strings to use single byte chars in backing store") \
1118 \
1119 product_pd(uint, TypeProfileLevel, \
1120 "=XYZ, with Z: Type profiling of arguments at call; " \
1121 "Y: Type profiling of return value at call; " \
1122 "X: Type profiling of parameters to methods; " \
1123 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1124 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1125 \
1126 product(int, TypeProfileArgsLimit, 2, \
1127 "max number of call arguments to consider for type profiling") \
1128 range(0, 16) \
1129 \
1130 product(int, TypeProfileParmsLimit, 2, \
1131 "max number of incoming parameters to consider for type profiling"\
1132 ", -1 for all") \
1133 range(-1, 64) \
1134 \
1135 /* statistics */ \
1136 develop(bool, CountCompiledCalls, false, \
1137 "Count method invocations") \
1138 \
1139 develop(bool, ICMissHistogram, false, \
1140 "Produce histogram of IC misses") \
1141 \
1142 /* interpreter */ \
1143 product_pd(bool, RewriteBytecodes, \
1144 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1145 \
1146 product_pd(bool, RewriteFrequentPairs, \
1147 "Rewrite frequently used bytecode pairs into a single bytecode") \
1148 \
1149 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1150 "Print the generated interpreter code") \
1151 \
1152 product(bool, UseInterpreter, true, \
1153 "Use interpreter for non-compiled methods") \
1154 \
1155 develop(bool, UseFastSignatureHandlers, true, \
1156 "Use fast signature handlers for native calls") \
1157 \
1158 product(bool, UseLoopCounter, true, \
1159 "Increment invocation counter on backward branch") \
1160 \
1161 product_pd(bool, UseOnStackReplacement, \
1162 "Use on stack replacement, calls runtime if invoc. counter " \
1163 "overflows in loop") \
1164 \
1165 develop(bool, TraceOnStackReplacement, false, \
1166 "Trace on stack replacement") \
1167 \
1168 product_pd(bool, PreferInterpreterNativeStubs, \
1169 "Use always interpreter stubs for native methods invoked via " \
1170 "interpreter") \
1171 \
1172 develop(bool, CountBytecodes, false, \
1173 "Count number of bytecodes executed") \
1174 \
1175 develop(bool, PrintBytecodeHistogram, false, \
1176 "Print histogram of the executed bytecodes") \
1177 \
1178 develop(bool, PrintBytecodePairHistogram, false, \
1179 "Print histogram of the executed bytecode pairs") \
1180 \
1181 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1182 "Print code generated for native method signature handlers") \
1183 \
1184 develop(bool, VerifyOops, false, \
1185 "Do plausibility checks for oops") \
1186 \
1187 develop(bool, CheckUnhandledOops, false, \
1188 "Check for unhandled oops in VM code") \
1189 \
1190 develop(bool, VerifyJNIFields, trueInDebug, \
1191 "Verify jfieldIDs for instance fields") \
1192 \
1193 develop(bool, VerifyActivationFrameSize, false, \
1194 "Verify that activation frame didn't become smaller than its " \
1195 "minimal size") \
1196 \
1197 develop(bool, TraceFrequencyInlining, false, \
1198 "Trace frequency based inlining") \
1199 \
1200 develop_pd(bool, InlineIntrinsics, \
1201 "Use intrinsics in Interpreter that can be statically resolved") \
1202 \
1203 product_pd(bool, ProfileInterpreter, \
1204 "Profile at the bytecode level during interpretation") \
1205 \
1206 develop_pd(bool, ProfileTraps, \
1207 "Profile deoptimization traps at the bytecode level") \
1208 \
1209 product(intx, ProfileMaturityPercentage, 20, \
1210 "number of method invocations/branches (expressed as % of " \
1211 "CompileThreshold) before using the method's profile") \
1212 range(0, 100) \
1213 \
1214 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1215 "Print the results of +ProfileInterpreter at end of run") \
1216 \
1217 develop(bool, VerifyDataPointer, trueInDebug, \
1218 "Verify the method data pointer during interpreter profiling") \
1219 \
1220 develop(bool, CrashGCForDumpingJavaThread, false, \
1221 "Manually make GC thread crash then dump java stack trace; " \
1222 "Test only") \
1223 \
1224 /* compilation */ \
1225 product(bool, UseCompiler, true, \
1226 "Use Just-In-Time compilation") \
1227 \
1228 product(bool, AlwaysCompileLoopMethods, false, \
1229 "When using recompilation, never interpret methods " \
1230 "containing loops") \
1231 \
1232 product(int, AllocatePrefetchStyle, 1, \
1233 "0 = no prefetch, " \
1234 "1 = generate prefetch instructions for each allocation, " \
1235 "2 = use TLAB watermark to gate allocation prefetch, " \
1236 "3 = generate one prefetch instruction per cache line") \
1237 range(0, 3) \
1238 \
1239 product(int, AllocatePrefetchDistance, -1, \
1240 "Distance to prefetch ahead of allocation pointer. " \
1241 "-1: use system-specific value (automatically determined") \
1242 range(-1, 512) \
1243 \
1244 product(int, AllocatePrefetchLines, 3, \
1245 "Number of lines to prefetch ahead of array allocation pointer") \
1246 range(1, 64) \
1247 \
1248 product(int, AllocateInstancePrefetchLines, 1, \
1249 "Number of lines to prefetch ahead of instance allocation " \
1250 "pointer") \
1251 range(1, 64) \
1252 \
1253 product(int, AllocatePrefetchStepSize, 16, \
1254 "Step size in bytes of sequential prefetch instructions") \
1255 range(1, 512) \
1256 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1257 \
1258 product(intx, AllocatePrefetchInstr, 0, \
1259 "Select instruction to prefetch ahead of allocation pointer") \
1260 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1261 \
1262 /* deoptimization */ \
1263 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1264 "Trace deoptimization") \
1265 \
1266 develop(bool, PrintDeoptimizationDetails, false, \
1267 "Print more information about deoptimization") \
1268 \
1269 develop(bool, DebugDeoptimization, false, \
1270 "Tracing various information while debugging deoptimization") \
1271 \
1272 product(double, SelfDestructTimer, 0.0, \
1273 "Will cause VM to terminate after a given time " \
1274 "(in fractional minutes) " \
1275 "(0.0 means off)") \
1276 range(0.0, (double)max_intx) \
1277 \
1278 product(int, MaxJavaStackTraceDepth, 1024, \
1279 "The maximum number of lines in the stack trace for Java " \
1280 "exceptions (0 means all)") \
1281 range(0, max_jint/2) \
1282 \
1283 /* notice: the max range value here is max_jint, not max_intx */ \
1284 /* because of overflow issue */ \
1285 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1286 "Guarantee a safepoint (at least) every so many milliseconds " \
1287 "(0 means none)") \
1288 range(0, max_jint) \
1289 \
1290 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1291 "Wake the ServiceThread to do periodic cleanup checks every so " \
1292 "many milliseconds (0 means none)") \
1293 range(0, max_jint) \
1294 \
1295 product(double, SafepointTimeoutDelay, 10000, \
1296 "Delay in milliseconds for option SafepointTimeout; " \
1297 "supports sub-millisecond resolution with fractional values.") \
1298 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1299 \
1300 product(bool, UseSystemMemoryBarrier, false, \
1301 "Try to enable system memory barrier if supported by OS") \
1302 \
1303 product(intx, NmethodSweepActivity, 4, \
1304 "Removes cold nmethods from code cache if > 0. Higher values " \
1305 "result in more aggressive sweeping") \
1306 range(0, 2000) \
1307 \
1308 develop(intx, MallocCatchPtr, -1, \
1309 "Hit breakpoint when mallocing/freeing this pointer") \
1310 \
1311 develop(int, StackPrintLimit, 100, \
1312 "number of stack frames to print in VM-level stack dump") \
1313 \
1314 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1315 "max number of compiled code units to print in error log") \
1316 range(0, VMError::max_error_log_print_code) \
1317 \
1318 develop(int, MaxElementPrintSize, 256, \
1319 "maximum number of elements to print") \
1320 \
1321 develop(int, MaxStringPrintSize, 256, \
1322 "maximum number of characters to print for a java.lang.String " \
1323 "in the VM. If exceeded, an abridged version of the string is " \
1324 "printed with the middle of the string elided.") \
1325 range(2, O_BUFLEN) \
1326 \
1327 develop(intx, MaxSubklassPrintSize, 4, \
1328 "maximum number of subklasses to print when printing klass") \
1329 \
1330 develop(intx, MaxForceInlineLevel, 100, \
1331 "maximum number of nested calls that are forced for inlining " \
1332 "(using CompileCommand or marked w/ @ForceInline)") \
1333 range(0, max_jint) \
1334 \
1335 develop(intx, MethodHistogramCutoff, 100, \
1336 "The cutoff value for method invocation histogram (+CountCalls)") \
1337 \
1338 develop(intx, DeoptimizeALotInterval, 5, \
1339 "Number of exits until DeoptimizeALot kicks in") \
1340 \
1341 develop(intx, ZombieALotInterval, 5, \
1342 "Number of exits until ZombieALot kicks in") \
1343 \
1344 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1345 "Limit malloc allocation size from VM. Reaching a limit will " \
1346 "trigger an action (see flag). This feature requires " \
1347 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1348 "Usage:" \
1349 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1350 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1351 "sets one or more category-specific limits." \
1352 "<flag> defines the action upon reaching the limit:" \
1353 "\"fatal\": end VM with a fatal error at the allocation site" \
1354 "\"oom\" : will mimic a native OOM" \
1355 "If <flag> is omitted, \"fatal\" is the default." \
1356 "Examples:\n" \
1357 "-XX:MallocLimit=2g" \
1358 "-XX:MallocLimit=2g:oom" \
1359 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1360 \
1361 product(intx, TypeProfileWidth, 2, \
1362 "Number of receiver types to record in call/cast profile") \
1363 range(0, 8) \
1364 \
1365 develop(intx, BciProfileWidth, 2, \
1366 "Number of return bci's to record in ret profile") \
1367 \
1368 product(intx, PerMethodRecompilationCutoff, 400, \
1369 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1370 range(-1, max_intx) \
1371 \
1372 product(intx, PerBytecodeRecompilationCutoff, 200, \
1373 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1374 range(-1, max_intx) \
1375 \
1376 product(intx, PerMethodTrapLimit, 100, \
1377 "Limit on traps (of one kind) in a method (includes inlines)") \
1378 range(0, max_jint) \
1379 \
1380 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1381 "Limit on speculative traps (of one kind) in a method " \
1382 "(includes inlines)") \
1383 range(0, max_jint) \
1384 \
1385 product(intx, PerBytecodeTrapLimit, 4, \
1386 "Limit on traps (of one kind) at a particular BCI") \
1387 range(0, max_jint) \
1388 \
1389 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1390 "Extra method data trap entries for speculation") \
1391 range(0, 100) \
1392 \
1393 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1394 "Ratio of call site execution to caller method invocation") \
1395 \
1396 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1397 "Minimum ratio of call site execution to caller method" \
1398 "invocation to be considered for inlining") \
1399 \
1400 develop(intx, InlineThrowCount, 50, \
1401 "Force inlining of interpreted methods that throw this often") \
1402 range(0, max_jint) \
1403 \
1404 develop(intx, InlineThrowMaxSize, 200, \
1405 "Force inlining of throwing methods smaller than this") \
1406 range(0, max_jint) \
1407 \
1408 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1409 "Initial threshold (in bytes) at which a garbage collection " \
1410 "is done to reduce Metaspace usage") \
1411 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1412 \
1413 product(size_t, MaxMetaspaceSize, max_uintx, \
1414 "Maximum size of Metaspaces (in bytes)") \
1415 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1416 \
1417 product(size_t, CompressedClassSpaceSize, 1*G, \
1418 "Maximum size of class area in Metaspace when compressed " \
1419 "class pointers are used") \
1420 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1421 \
1422 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1423 "Force the class space to be allocated at this address or " \
1424 "fails VM initialization (requires -Xshare=off.") \
1425 \
1426 develop(bool, RandomizeClassSpaceLocation, true, \
1427 "Randomize location of class space.") \
1428 \
1429 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1430 "Print metaspace statistics upon VM exit.") \
1431 \
1432 product(bool, PrintCompilerMemoryStatisticsAtExit, false, DIAGNOSTIC, \
1433 "Print compiler memory statistics upon VM exit.") \
1434 \
1435 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1436 "The minimum percentage of heap free after GC to avoid expansion."\
1437 " For most GCs this applies to the old generation. In G1 and" \
1438 " ParallelGC it applies to the whole heap.") \
1439 range(0, 100) \
1440 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1441 \
1442 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1443 "The maximum percentage of heap free after GC to avoid shrinking."\
1444 " For most GCs this applies to the old generation. In G1 and" \
1445 " ParallelGC it applies to the whole heap.") \
1446 range(0, 100) \
1447 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1448 \
1449 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1450 "Number of milliseconds per MB of free space in the heap") \
1451 range(0, max_intx) \
1452 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1453 \
1454 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1455 "The minimum change in heap space due to GC (in bytes)") \
1456 range(0, max_uintx / 2 + 1) \
1457 \
1458 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1459 "The minimum expansion of Metaspace (in bytes)") \
1460 range(0, max_uintx) \
1461 \
1462 product(uint, MaxMetaspaceFreeRatio, 70, \
1463 "The maximum percentage of Metaspace free after GC to avoid " \
1464 "shrinking") \
1465 range(0, 100) \
1466 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1467 \
1468 product(uint, MinMetaspaceFreeRatio, 40, \
1469 "The minimum percentage of Metaspace free after GC to avoid " \
1470 "expansion") \
1471 range(0, 99) \
1472 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1473 \
1474 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1475 "The maximum expansion of Metaspace without full GC (in bytes)") \
1476 range(0, max_uintx) \
1477 \
1478 /* stack parameters */ \
1479 product_pd(intx, StackYellowPages, \
1480 "Number of yellow zone (recoverable overflows) pages of size " \
1481 "4KB. If pages are bigger yellow zone is aligned up.") \
1482 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1483 \
1484 product_pd(intx, StackRedPages, \
1485 "Number of red zone (unrecoverable overflows) pages of size " \
1486 "4KB. If pages are bigger red zone is aligned up.") \
1487 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1488 \
1489 product_pd(intx, StackReservedPages, \
1490 "Number of reserved zone (reserved to annotated methods) pages" \
1491 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1492 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1493 \
1494 product(bool, RestrictReservedStack, true, \
1495 "Restrict @ReservedStackAccess to trusted classes") \
1496 \
1497 /* greater stack shadow pages can't generate instruction to bang stack */ \
1498 product_pd(intx, StackShadowPages, \
1499 "Number of shadow zone (for overflow checking) pages of size " \
1500 "4KB. If pages are bigger shadow zone is aligned up. " \
1501 "This should exceed the depth of the VM and native call stack.") \
1502 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1503 \
1504 product_pd(intx, ThreadStackSize, \
1505 "Thread Stack Size (in Kbytes)") \
1506 range(0, 1 * M) \
1507 \
1508 product_pd(intx, VMThreadStackSize, \
1509 "Non-Java Thread Stack Size (in Kbytes)") \
1510 range(0, max_intx/(1 * K)) \
1511 \
1512 product_pd(intx, CompilerThreadStackSize, \
1513 "Compiler Thread Stack Size (in Kbytes)") \
1514 range(0, max_intx/(1 * K)) \
1515 \
1516 develop_pd(size_t, JVMInvokeMethodSlack, \
1517 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1518 \
1519 /* code cache parameters */ \
1520 product_pd(size_t, CodeCacheSegmentSize, EXPERIMENTAL, \
1521 "Code cache segment size (in bytes) - smallest unit of " \
1522 "allocation") \
1523 range(1, 1024) \
1524 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1525 \
1526 product_pd(uint, CodeEntryAlignment, EXPERIMENTAL, \
1527 "Code entry alignment for generated code" \
1528 " (in bytes, power of two)") \
1529 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1530 \
1531 product_pd(intx, OptoLoopAlignment, \
1532 "Align inner loops to zero relative to this modulus") \
1533 range(1, 128) \
1534 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1535 \
1536 product_pd(size_t, InitialCodeCacheSize, \
1537 "Initial code cache size (in bytes)") \
1538 constraint(VMPageSizeConstraintFunc, AtParse) \
1539 \
1540 develop_pd(size_t, CodeCacheMinimumUseSpace, \
1541 "Minimum code cache size (in bytes) required to start VM.") \
1542 range(0, SIZE_MAX) \
1543 \
1544 product(bool, SegmentedCodeCache, false, \
1545 "Use a segmented code cache") \
1546 \
1547 product_pd(size_t, ReservedCodeCacheSize, \
1548 "Reserved code cache size (in bytes) - maximum code cache size") \
1549 constraint(VMPageSizeConstraintFunc, AtParse) \
1550 \
1551 product_pd(size_t, NonProfiledCodeHeapSize, \
1552 "Size of code heap with non-profiled methods (in bytes)") \
1553 range(0, SIZE_MAX) \
1554 \
1555 product_pd(size_t, ProfiledCodeHeapSize, \
1556 "Size of code heap with profiled methods (in bytes)") \
1557 range(0, SIZE_MAX) \
1558 \
1559 product_pd(size_t, NonNMethodCodeHeapSize, \
1560 "Size of code heap with non-nmethods (in bytes)") \
1561 constraint(VMPageSizeConstraintFunc, AtParse) \
1562 \
1563 product(size_t, HotCodeHeapSize, 0, EXPERIMENTAL, \
1564 "Size of code heap with predicted hot methods (in bytes)") \
1565 range(0, SIZE_MAX) \
1566 \
1567 product_pd(size_t, CodeCacheExpansionSize, \
1568 "Code cache expansion size (in bytes)") \
1569 range(32*K, SIZE_MAX) \
1570 \
1571 product_pd(size_t, CodeCacheMinBlockLength, DIAGNOSTIC, \
1572 "Minimum number of segments in a code cache block") \
1573 range(1, 100) \
1574 \
1575 develop(bool, ExitOnFullCodeCache, false, \
1576 "Exit the VM if we fill the code cache") \
1577 \
1578 product(bool, UseCodeCacheFlushing, true, \
1579 "Remove cold/old nmethods from the code cache") \
1580 \
1581 product(double, SweeperThreshold, 15.0, \
1582 "Threshold when a code cache unloading GC is invoked." \
1583 "Value is percentage of ReservedCodeCacheSize.") \
1584 range(0.0, 100.0) \
1585 \
1586 product(uintx, StartAggressiveSweepingAt, 10, \
1587 "Start aggressive sweeping if less than X[%] of the total code cache is free.")\
1588 range(0, 100) \
1589 \
1590 product(bool, NMethodRelocation, false, EXPERIMENTAL, \
1591 "Enables use of experimental function nmethod::relocate()") \
1592 \
1593 /* interpreter debugging */ \
1594 develop(intx, BinarySwitchThreshold, 5, \
1595 "Minimal number of lookupswitch entries for rewriting to binary " \
1596 "switch") \
1597 \
1598 develop(uintx, StopInterpreterAt, 0, \
1599 "Stop interpreter execution at specified bytecode number") \
1600 \
1601 develop(uintx, TraceBytecodesAt, 0, \
1602 "Trace bytecodes starting with specified bytecode number") \
1603 \
1604 develop(uintx, TraceBytecodesStopAt, 0, \
1605 "Stop bytecode tracing at the specified bytecode number") \
1606 \
1607 /* Priorities */ \
1608 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1609 \
1610 product(int, ThreadPriorityPolicy, 0, \
1611 "0 : Normal. "\
1612 " VM chooses priorities that are appropriate for normal "\
1613 " applications. "\
1614 " On Windows applications are allowed to use higher native "\
1615 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1616 " not use the highest possible native priority, "\
1617 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1618 " system threads. On Linux thread priorities are ignored "\
1619 " because the OS does not support static priority in "\
1620 " SCHED_OTHER scheduling class which is the only choice for "\
1621 " non-root, non-realtime applications. "\
1622 "1 : Aggressive. "\
1623 " Java thread priorities map over to the entire range of "\
1624 " native thread priorities. Higher Java thread priorities map "\
1625 " to higher native thread priorities. This policy should be "\
1626 " used with care, as sometimes it can cause performance "\
1627 " degradation in the application and/or the entire system. On "\
1628 " Linux/BSD/macOS this policy requires root privilege or an "\
1629 " extended capability.") \
1630 range(0, 1) \
1631 \
1632 product(bool, ThreadPriorityVerbose, false, \
1633 "Print priority changes") \
1634 \
1635 product(int, CompilerThreadPriority, -1, \
1636 "The native priority at which compiler threads should run " \
1637 "(-1 means no change)") \
1638 range(min_jint, max_jint) \
1639 \
1640 product(int, VMThreadPriority, -1, \
1641 "The native priority at which the VM thread should run " \
1642 "(-1 means no change)") \
1643 range(min_jint, max_jint) \
1644 \
1645 product(int, JavaPriority1_To_OSPriority, -1, \
1646 "Map Java priorities to OS priorities") \
1647 range(min_jint, max_jint) \
1648 \
1649 product(int, JavaPriority2_To_OSPriority, -1, \
1650 "Map Java priorities to OS priorities") \
1651 range(min_jint, max_jint) \
1652 \
1653 product(int, JavaPriority3_To_OSPriority, -1, \
1654 "Map Java priorities to OS priorities") \
1655 range(min_jint, max_jint) \
1656 \
1657 product(int, JavaPriority4_To_OSPriority, -1, \
1658 "Map Java priorities to OS priorities") \
1659 range(min_jint, max_jint) \
1660 \
1661 product(int, JavaPriority5_To_OSPriority, -1, \
1662 "Map Java priorities to OS priorities") \
1663 range(min_jint, max_jint) \
1664 \
1665 product(int, JavaPriority6_To_OSPriority, -1, \
1666 "Map Java priorities to OS priorities") \
1667 range(min_jint, max_jint) \
1668 \
1669 product(int, JavaPriority7_To_OSPriority, -1, \
1670 "Map Java priorities to OS priorities") \
1671 range(min_jint, max_jint) \
1672 \
1673 product(int, JavaPriority8_To_OSPriority, -1, \
1674 "Map Java priorities to OS priorities") \
1675 range(min_jint, max_jint) \
1676 \
1677 product(int, JavaPriority9_To_OSPriority, -1, \
1678 "Map Java priorities to OS priorities") \
1679 range(min_jint, max_jint) \
1680 \
1681 product(int, JavaPriority10_To_OSPriority,-1, \
1682 "Map Java priorities to OS priorities") \
1683 range(min_jint, max_jint) \
1684 \
1685 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1686 "Java thread priority 10 maps to critical scheduling priority") \
1687 \
1688 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1689 "Compiler thread(s) run at critical scheduling priority") \
1690 \
1691 develop(intx, NewCodeParameter, 0, \
1692 "Testing Only: Create a dedicated integer parameter before " \
1693 "putback") \
1694 \
1695 /* new oopmap storage allocation */ \
1696 develop(int, MinOopMapAllocation, 8, \
1697 "Minimum number of OopMap entries in an OopMapSet") \
1698 range(0, max_jint) \
1699 \
1700 /* recompilation */ \
1701 product_pd(intx, CompileThreshold, \
1702 "number of interpreted method invocations before (re-)compiling") \
1703 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1704 \
1705 product_pd(bool, TieredCompilation, \
1706 "Enable tiered compilation") \
1707 \
1708 /* Properties for Java libraries */ \
1709 \
1710 product(uint64_t, MaxDirectMemorySize, 0, \
1711 "Maximum total size of NIO direct-buffer allocations. " \
1712 "Ignored if not explicitly set.") \
1713 range(0, max_jlong) \
1714 \
1715 /* Flags used for temporary code during development */ \
1716 \
1717 product(bool, UseNewCode, false, DIAGNOSTIC, \
1718 "Testing Only: Use the new version while testing") \
1719 \
1720 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1721 "Testing Only: Use the new version while testing") \
1722 \
1723 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1724 "Testing Only: Use the new version while testing") \
1725 \
1726 develop(bool, UseDebuggerErgo, false, \
1727 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1728 "Turns on the other UseDebuggerErgo* flags") \
1729 \
1730 develop(bool, UseDebuggerErgo1, false, \
1731 "Debugging Only: Enable workarounds for debugger induced " \
1732 "os::processor_id() >= os::processor_count() problems") \
1733 \
1734 develop(bool, UseDebuggerErgo2, false, \
1735 "Debugging Only: Limit the number of spawned JVM threads") \
1736 \
1737 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1738 "Enable JVMTI asserts related to stack depth checks") \
1739 \
1740 /* flags for performance data collection */ \
1741 \
1742 product(bool, UsePerfData, true, \
1743 "Flag to disable jvmstat instrumentation for performance testing "\
1744 "and problem isolation purposes") \
1745 \
1746 product(bool, PerfDataSaveToFile, false, \
1747 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1748 \
1749 product(ccstr, PerfDataSaveFile, nullptr, \
1750 "Save PerfData memory to the specified absolute pathname. " \
1751 "The string %p in the file name (if present) " \
1752 "will be replaced by pid") \
1753 \
1754 product(bool, PerfDisableSharedMem, false, \
1755 "Store performance data in standard memory") \
1756 \
1757 product(int, PerfDataMemorySize, 32*K, \
1758 "Size of performance data memory region. Will be rounded " \
1759 "up to a multiple of the native os page size.") \
1760 range(128, 32*64*K) \
1761 \
1762 product(int, PerfMaxStringConstLength, 1024, \
1763 "Maximum PerfStringConstant string length before truncation") \
1764 range(32, 32*K) \
1765 \
1766 product(bool, PerfAllowAtExitRegistration, false, \
1767 "Allow registration of atexit() methods") \
1768 \
1769 product(bool, PerfBypassFileSystemCheck, false, \
1770 "Bypass Win32 file system criteria checks (Windows Only)") \
1771 \
1772 product(int, UnguardOnExecutionViolation, 0, \
1773 "Unguard page and retry on no-execute fault (Win32 only) " \
1774 "0=off, 1=conservative, 2=aggressive") \
1775 range(0, 2) \
1776 \
1777 /* Serviceability Support */ \
1778 \
1779 product(bool, ManagementServer, false, \
1780 "Create JMX Management Server") \
1781 \
1782 product(bool, DisableAttachMechanism, false, \
1783 "Disable mechanism that allows tools to attach to this VM") \
1784 \
1785 product(bool, StartAttachListener, false, \
1786 "Always start Attach Listener at VM startup") \
1787 \
1788 product(bool, EnableDynamicAgentLoading, true, \
1789 "Allow tools to load agents with the attach mechanism") \
1790 \
1791 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1792 "Print java.util.concurrent locks in thread dump") \
1793 \
1794 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1795 "Print generated stub code for method handles") \
1796 \
1797 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1798 "perform extra checks when constructing method handles") \
1799 \
1800 product(bool, IgnoreAssertUnsetFields, false, DIAGNOSTIC, \
1801 "Ignore assert_unset_fields") \
1802 \
1803 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1804 "show method handle implementation frames (usually hidden)") \
1805 \
1806 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1807 "show virtual threads' carrier frames in exceptions") \
1808 \
1809 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1810 "trust final non-static declarations for constant folding") \
1811 \
1812 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1813 "Optimize loads from stable fields (marked w/ @Stable)") \
1814 \
1815 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1816 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1817 "resolved before the bootstrap method is called; 1: when a BSM " \
1818 "that may accept a BootstrapCallInfo is detected, use that API " \
1819 "to pass BSM arguments, which allows the BSM to delay their " \
1820 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1821 "via that API, instead of with the eagerly-resolved array.") \
1822 \
1823 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1824 "Causes the VM to pause at startup time and wait for the pause " \
1825 "file to be removed (default: ./vm.paused.<pid>)") \
1826 \
1827 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1828 "The file to create and for whose removal to await when pausing " \
1829 "at startup. (default: ./vm.paused.<pid>)") \
1830 \
1831 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1832 "Pause and wait for keypress on exit if a debugger is attached") \
1833 \
1834 product(bool, DTraceMethodProbes, false, \
1835 "Enable dtrace tool probes for method-entry and method-exit") \
1836 \
1837 product(bool, DTraceAllocProbes, false, \
1838 "Enable dtrace tool probes for object allocation") \
1839 \
1840 product(bool, DTraceMonitorProbes, false, \
1841 "Enable dtrace tool probes for monitor events") \
1842 \
1843 product(bool, RelaxAccessControlCheck, false, \
1844 "Relax the access control checks in the verifier") \
1845 \
1846 product(uintx, StringTableSize, defaultStringTableSize, \
1847 "Number of buckets in the interned String table " \
1848 "(will be rounded to nearest higher power of 2)") \
1849 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1850 \
1851 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1852 "Number of buckets in the JVM internal Symbol table") \
1853 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1854 \
1855 product(bool, UseStringDeduplication, false, \
1856 "Use string deduplication") \
1857 \
1858 product(uint, StringDeduplicationAgeThreshold, 3, \
1859 "A string must reach this age (or be promoted to an old region) " \
1860 "to be considered for deduplication") \
1861 range(1, markWord::max_age) \
1862 \
1863 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1864 "Approximate initial number of buckets in the table") \
1865 range(1, 1 * G) \
1866 \
1867 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1868 "Entries per bucket above which the table should be expanded") \
1869 range(0.1, 1000.0) \
1870 \
1871 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1872 "Entries per bucket below which the table should be shrunk") \
1873 range(0.01, 100.0) \
1874 \
1875 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1876 "Desired entries per bucket when resizing the table") \
1877 range(0.01, 1000.0) \
1878 \
1879 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1880 "Minimum number of dead table entries for cleaning the table") \
1881 \
1882 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1883 "Minimum percentage of dead table entries for cleaning the table") \
1884 range(1, 100) \
1885 \
1886 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1887 "Force more frequent table resizing") \
1888 \
1889 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1890 "Seed for the table hashing function; 0 requests computed seed") \
1891 \
1892 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1893 "Enable internal testing APIs") \
1894 \
1895 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1896 "Use unaligned memory accesses in Unsafe") \
1897 \
1898 product_pd(bool, PreserveFramePointer, \
1899 "Use the FP register for holding the frame pointer " \
1900 "and not as a general purpose register.") \
1901 \
1902 product(size_t, AsyncLogBufferSize, 2*M, \
1903 "Memory budget (in bytes) for the buffer of Asynchronous " \
1904 "Logging (-Xlog:async).") \
1905 range(DEBUG_ONLY(192) NOT_DEBUG(100*K), 50*M) \
1906 \
1907 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1908 "When a class C is loaded, check that " \
1909 "(1) all intrinsics defined by the VM for class C are present "\
1910 "in the loaded class file and are marked with the " \
1911 "@IntrinsicCandidate annotation, that " \
1912 "(2) there is an intrinsic registered for all loaded methods " \
1913 "that are annotated with the @IntrinsicCandidate annotation, " \
1914 "and that " \
1915 "(3) no orphan methods exist for class C (i.e., methods for " \
1916 "which the VM declares an intrinsic but that are not declared "\
1917 "in the loaded class C. " \
1918 "Check (3) is available only in debug builds.") \
1919 \
1920 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1921 "Threshold small size (in bytes) for clearing arrays. " \
1922 "Anything this size or smaller may get converted to discrete " \
1923 "scalar stores.") \
1924 range(0, max_intx) \
1925 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1926 \
1927 product(ccstr, AllocateHeapAt, nullptr, \
1928 "Path to the directory where a temporary file will be created " \
1929 "to use as the backing store for Java Heap.") \
1930 \
1931 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1932 "Enable VM continuations support") \
1933 \
1934 develop(bool, LoomDeoptAfterThaw, false, \
1935 "Deopt stack after thaw") \
1936 \
1937 develop(bool, LoomVerifyAfterThaw, false, \
1938 "Verify stack after thaw") \
1939 \
1940 develop(bool, VerifyContinuations, false, \
1941 "Verify continuation consistency") \
1942 \
1943 develop(bool, UseContinuationFastPath, true, \
1944 "Use fast-path frame walking in continuations") \
1945 \
1946 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1947 "Run periodic metaspace verifications (0 - none, " \
1948 "1 - always, >1 every nth interval)") \
1949 \
1950 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1951 "On internal errors, include registers in error report.") \
1952 \
1953 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1954 "leverage profiling for table/lookup switch") \
1955 \
1956 develop(bool, TraceMemoryWriteback, false, \
1957 "Trace memory writeback operations") \
1958 \
1959 JFR_ONLY(product(bool, FlightRecorder, false, \
1960 "(Deprecated) Enable Flight Recorder")) \
1961 \
1962 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1963 "Flight Recorder options")) \
1964 \
1965 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1966 "Start flight recording with options")) \
1967 \
1968 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1969 "Use platform unstable time where supported for timestamps only") \
1970 \
1971 product_pd(bool, InlineTypePassFieldsAsArgs, DIAGNOSTIC, \
1972 "Pass each inline type field as an argument at calls") \
1973 \
1974 product_pd(bool, InlineTypeReturnedAsFields, DIAGNOSTIC, \
1975 "Return fields instead of an inline type reference") \
1976 \
1977 develop(bool, StressCallingConvention, false, \
1978 "Stress the scalarized calling convention.") \
1979 \
1980 develop(bool, PreloadClasses, true, \
1981 "Preloading all classes from the LoadableDescriptors attribute") \
1982 \
1983 product(ccstrlist, ForceNonTearable, "", DIAGNOSTIC, \
1984 "List of inline classes which are forced to be atomic " \
1985 "(whitespace and commas separate names, " \
1986 "and leading and trailing stars '*' are wildcards)") \
1987 \
1988 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1989 "Make nmethod barriers deoptimise a lot.") \
1990 \
1991 develop(bool, VerifyCrossModifyFence, \
1992 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1993 "Mark all threads after a safepoint, and clear on a modify " \
1994 "fence. Add cleanliness checks.") \
1995 \
1996 product(bool, UseObjectMonitorTable, true, DIAGNOSTIC, \
1997 "Use a table to record inflated monitors rather than the first " \
1998 "word of the object.") \
1999 \
2000 product(int, FastLockingSpins, 8, DIAGNOSTIC, \
2001 "Specifies the number of times fast locking will attempt to " \
2002 "CAS the markWord before inflating. Between each CAS it will " \
2003 "spin for exponentially more time, resulting in a total number " \
2004 "of spins on the order of O(2^value)") \
2005 range(1, 30) \
2006 \
2007 product(uint, TrimNativeHeapInterval, 0, \
2008 "Interval, in ms, at which the JVM will trim the native heap if " \
2009 "the platform supports that. Lower values will reclaim memory " \
2010 "more eagerly at the cost of higher overhead. A value of 0 " \
2011 "(default) disables native heap trimming.") \
2012 range(0, UINT_MAX) \
2013 \
2014 develop(bool, SimulateFullAddressSpace, false, \
2015 "Simulates a very populated, fragmented address space; no " \
2016 "targeted reservations will succeed.") \
2017 \
2018 product(bool, ProfileExceptionHandlers, true, \
2019 "Profile exception handlers") \
2020 \
2021 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
2022 "Unconditionally record nmethod dependencies on class " \
2023 "rewriting/transformation independently of the JVMTI " \
2024 "can_{retransform/redefine}_classes capabilities.") \
2025 \
2026 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
2027 "Use secondary supers cache during subtype checks.") \
2028 \
2029 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
2030 "Use hash table to lookup secondary supers.") \
2031 \
2032 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
2033 "Check that linear and hashed secondary lookups return the same result.") \
2034 \
2035 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
2036 "Use a terrible hash function in order to generate many collisions.") \
2037 \
2038 product(bool, UseThreadsLockThrottleLock, true, DIAGNOSTIC, \
2039 "Use an extra lock during Thread start and exit to alleviate" \
2040 "contention on Threads_lock.") \
2041 \
2042 develop(uint, BinarySearchThreshold, 16, \
2043 "Minimal number of elements in a sorted collection to prefer" \
2044 "binary search over simple linear search." ) \
2045 \
2046 product(bool, UseAcmpFastPath, true, DIAGNOSTIC, \
2047 "Use fast path for acmp.") \
2048
2049 // end of RUNTIME_FLAGS
2050
2051 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2052 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2053 DECLARE_FLAGS(RUNTIME_FLAGS)
2054 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2055
2056 #endif // SHARE_RUNTIME_GLOBALS_HPP