1 /*
2 * Copyright (c) 1997, 2023, 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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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 // notproduct flags are settable / visible only during development and are not declared in the PRODUCT version
40 // develop_pd/product_pd flags are the same as develop/product, except that their default values
41 // are specified in platform-dependent header files.
42
43 // Flags must be declared with the following number of parameters:
44 // non-pd flags:
45 // (type, name, default_value, doc), or
46 // (type, name, default_value, extra_attrs, doc)
47 // pd flags:
48 // (type, name, doc), or
49 // (type, name, extra_attrs, doc)
50
51 // A flag must be declared with one of the following types:
52 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t.
53 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used
54 // only in this file, because the macrology requires single-token type names.
55
56 // The optional extra_attrs parameter may have one of the following values:
57 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used
58 // only with product/product_pd flags.
59 //
60 // DIAGNOSTIC options are not meant for VM tuning or for product modes.
61 // They are to be used for VM quality assurance or field diagnosis
62 // of VM bugs. They are hidden so that users will not be encouraged to
63 // try them as if they were VM ordinary execution options. However, they
64 // are available in the product version of the VM. Under instruction
65 // from support engineers, VM customers can turn them on to collect
66 // diagnostic information about VM problems. To use a VM diagnostic
67 // option, you must first specify +UnlockDiagnosticVMOptions.
68 // (This master switch also affects the behavior of -Xprintflags.)
69 //
70 // EXPERIMENTAL flags are in support of features that may not be
71 // an officially supported part of a product, but may be available
72 // for experimenting with. They could, for example, be performance
73 // features that may not have undergone full or rigorous QA, but which may
74 // help performance in some cases and released for experimentation
75 // by the community of users and developers. This flag also allows one to
76 // be able to build a fully supported product that nonetheless also
77 // ships with some unsupported, lightly tested, experimental features.
78 // Refer to the documentation of any products using this code for details
79 // on support and fitness for production.
80 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
81 // UnlockExperimentalVMOptions flag, which allows the control and
82 // modification of the experimental flags.
83 //
84 // Nota bene: neither diagnostic nor experimental options should be used casually,
85 // Refer to the documentation of any products using this code for details.
86 //
87 // MANAGEABLE flags are writeable external product flags.
88 // They are dynamically writeable through the JDK management interface
89 // (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole.
90 // These flags are external exported interface (see CSR). The list of
91 // manageable flags can be queried programmatically through the management
92 // interface.
93 //
94 // A flag can be made as "manageable" only if
95 // - the flag is defined in a CSR request as an external exported interface.
96 // - the VM implementation supports dynamic setting of the flag.
97 // This implies that the VM must *always* query the flag variable
98 // and not reuse state related to the flag state at any given time.
99 // - you want the flag to be queried programmatically by the customers.
100 //
101
102 //
103 // range is a macro that will expand to min and max arguments for range
104 // checking code if provided - see jvmFlagLimit.hpp
105 //
106 // constraint is a macro that will expand to custom function call
107 // for constraint checking if provided - see jvmFlagLimit.hpp
108
109 // Default and minimum StringTable and SymbolTable size values
110 // Must be powers of 2
111 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536);
112 const size_t minimumStringTableSize = 128;
113 const size_t defaultSymbolTableSize = 32768; // 2^15
114 const size_t minimumSymbolTableSize = 1024;
115
116 #ifdef _LP64
117 #define LP64_RUNTIME_FLAGS(develop, \
118 develop_pd, \
119 product, \
120 product_pd, \
121 notproduct, \
122 range, \
123 constraint) \
124 \
125 product(bool, UseCompressedOops, false, \
126 "Use 32-bit object references in 64-bit VM. " \
127 "lp64_product means flag is always constant in 32 bit VM") \
128 \
129 product(bool, UseCompressedClassPointers, true, \
130 "Use 32-bit class pointers in 64-bit VM. " \
131 "lp64_product means flag is always constant in 32 bit VM") \
132 \
133 product(int, ObjectAlignmentInBytes, 8, \
134 "Default object alignment in bytes, 8 is minimum") \
135 range(8, 256) \
136 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
137
138 #else
139 // !_LP64
140
141 #define LP64_RUNTIME_FLAGS(develop, \
142 develop_pd, \
143 product, \
144 product_pd, \
145 notproduct, \
146 range, \
147 constraint)
148 const bool UseCompressedOops = false;
149 const bool UseCompressedClassPointers = false;
150 const int ObjectAlignmentInBytes = 8;
151
152 #endif // _LP64
153
154 #define RUNTIME_FLAGS(develop, \
155 develop_pd, \
156 product, \
157 product_pd, \
158 notproduct, \
159 range, \
160 constraint) \
161 \
162 notproduct(bool, CheckCompressedOops, true, \
163 "Generate checks in encoding/decoding code in debug VM") \
164 \
165 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
166 "Heap allocation steps through preferred address regions to find" \
167 " where it can allocate the heap. Number of steps to take per " \
168 "region.") \
169 range(1, max_uintx) \
170 \
171 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
172 "If nonzero set a timeout in milliseconds for handshakes") \
173 \
174 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
175 "Force safe construction, as if all fields are final.") \
176 \
177 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
178 "Enable normal processing of flags relating to field diagnostics")\
179 \
180 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
181 "Enable normal processing of flags relating to experimental " \
182 "features") \
183 \
184 product(bool, JavaMonitorsInStackTrace, true, \
185 "Print information about Java monitor locks when the stacks are " \
186 "dumped") \
187 \
188 product_pd(bool, UseLargePages, \
189 "Use large page memory") \
190 \
191 product_pd(bool, UseLargePagesIndividualAllocation, \
192 "Allocate large pages individually for better affinity") \
193 \
194 develop(bool, LargePagesIndividualAllocationInjectError, false, \
195 "Fail large pages individual allocation") \
196 \
197 product(bool, UseNUMA, false, \
198 "Use NUMA if available") \
199 \
200 product(bool, UseNUMAInterleaving, false, \
201 "Interleave memory across NUMA nodes if available") \
202 \
203 product(size_t, NUMAInterleaveGranularity, 2*M, \
204 "Granularity to use for NUMA interleaving on Windows OS") \
205 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
206 \
207 product(uintx, NUMAChunkResizeWeight, 20, \
208 "Percentage (0-100) used to weight the current sample when " \
209 "computing exponentially decaying average for " \
210 "AdaptiveNUMAChunkSizing") \
211 range(0, 100) \
212 \
213 product(size_t, NUMASpaceResizeRate, 1*G, \
214 "Do not reallocate more than this amount per collection") \
215 range(0, max_uintx) \
216 \
217 product(bool, UseAdaptiveNUMAChunkSizing, true, \
218 "Enable adaptive chunk sizing for NUMA") \
219 \
220 product(bool, NUMAStats, false, \
221 "Print NUMA stats in detailed heap information") \
222 \
223 product(uintx, NUMAPageScanRate, 256, \
224 "Maximum number of pages to include in the page scan procedure") \
225 range(0, max_uintx) \
226 \
227 product(bool, UseAES, false, \
228 "Control whether AES instructions are used when available") \
229 \
230 product(bool, UseFMA, false, \
231 "Control whether FMA instructions are used when available") \
232 \
233 product(bool, UseSHA, false, \
234 "Control whether SHA instructions are used when available") \
235 \
236 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
237 "Use intrinsics for GHASH versions of crypto") \
238 \
239 product(bool, UseBASE64Intrinsics, false, \
240 "Use intrinsics for java.util.Base64") \
241 \
242 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
243 "Use intrinsics for sun.security.util.math.intpoly") \
244 \
245 product(size_t, LargePageSizeInBytes, 0, \
246 "Maximum large page size used (0 will use the default large " \
247 "page size for the environment as the maximum)") \
248 range(0, max_uintx) \
249 \
250 product(size_t, LargePageHeapSizeThreshold, 128*M, \
251 "Use large pages if maximum heap is at least this big") \
252 range(0, max_uintx) \
253 \
254 product(bool, ForceTimeHighResolution, false, \
255 "Using high time resolution (for Win32 only)") \
256 \
257 develop(bool, TracePcPatching, false, \
258 "Trace usage of frame::patch_pc") \
259 \
260 develop(bool, TraceRelocator, false, \
261 "Trace the bytecode relocator") \
262 \
263 \
264 product(bool, SafepointALot, false, DIAGNOSTIC, \
265 "Generate a lot of safepoints. This works with " \
266 "GuaranteedSafepointInterval") \
267 \
268 product(bool, HandshakeALot, false, DIAGNOSTIC, \
269 "Generate a lot of handshakes. This works with " \
270 "GuaranteedSafepointInterval") \
271 \
272 product_pd(bool, BackgroundCompilation, \
273 "A thread requesting compilation is not blocked during " \
274 "compilation") \
275 \
276 product(bool, MethodFlushing, true, \
277 "Reclamation of compiled methods") \
278 \
279 develop(bool, VerifyStack, false, \
280 "Verify stack of each thread when it is entering a runtime call") \
281 \
282 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
283 "Make all non code cache addresses to be unreachable by " \
284 "forcing use of 64bit literal fixups") \
285 \
286 develop(bool, TraceDerivedPointers, false, \
287 "Trace traversal of derived pointers on stack") \
288 \
289 notproduct(bool, TraceCodeBlobStacks, false, \
290 "Trace stack-walk of codeblobs") \
291 \
292 notproduct(bool, PrintRewrites, false, \
293 "Print methods that are being rewritten") \
294 \
295 product(bool, UseInlineCaches, true, \
296 "Use Inline Caches for virtual calls ") \
297 \
298 product(size_t, InlineCacheBufferSize, 10*K, EXPERIMENTAL, \
299 "InlineCacheBuffer size") \
300 \
301 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
302 "Inline arraycopy native that is known to be part of " \
303 "base library DLL") \
304 \
305 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
306 "Inline Object::hashCode() native that is known to be part " \
307 "of base library DLL") \
308 \
309 product(bool, InlineNatives, true, DIAGNOSTIC, \
310 "Inline natives that are known to be part of base library DLL") \
311 \
312 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
313 "Inline SinD, CosD, etc.") \
314 \
315 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
316 "Inline Class.isInstance, etc") \
317 \
318 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
319 "Inline Thread.currentThread, etc") \
320 \
321 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
322 "Inline memory ops (native methods) from Unsafe") \
323 \
324 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
325 "Use intrinsics for AES versions of crypto") \
326 \
327 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
328 "Use intrinsics for the paralleled version of AES/CTR crypto") \
329 \
330 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
331 "Use intrinsics for the vectorized version of ChaCha20") \
332 \
333 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
334 "Use intrinsics for MD5 crypto hash function") \
335 \
336 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
337 "Use intrinsics for SHA-1 crypto hash function. " \
338 "Requires that UseSHA is enabled.") \
339 \
340 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
341 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
342 "Requires that UseSHA is enabled.") \
343 \
344 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
345 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
346 "Requires that UseSHA is enabled.") \
347 \
348 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
349 "Use intrinsics for SHA3 crypto hash function. " \
350 "Requires that UseSHA is enabled.") \
351 \
352 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
353 "use intrinsics for java.util.zip.CRC32") \
354 \
355 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
356 "use intrinsics for java.util.zip.CRC32C") \
357 \
358 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
359 "use intrinsics for java.util.zip.Adler32") \
360 \
361 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
362 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
363 \
364 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
365 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
366 \
367 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
368 "Enables intrinsification of Math.copySign") \
369 \
370 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
371 "Enables intrinsification of Math.signum") \
372 \
373 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
374 "Use Compiler thread for compiler's stubs generation") \
375 \
376 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
377 "do not expand intrinsics whose (internal) names appear here") \
378 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
379 \
380 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
381 "Control intrinsics using a list of +/- (internal) names, " \
382 "separated by commas") \
383 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
384 \
385 develop(bool, TraceCallFixup, false, \
386 "Trace all call fixups") \
387 \
388 develop(bool, DeoptimizeALot, false, \
389 "Deoptimize at every exit from the runtime system") \
390 \
391 notproduct(ccstrlist, DeoptimizeOnlyAt, "", \
392 "A comma separated list of bcis to deoptimize at") \
393 \
394 develop(bool, DeoptimizeRandom, false, \
395 "Deoptimize random frames on random exit from the runtime system")\
396 \
397 notproduct(bool, ZombieALot, false, \
398 "Create non-entrant nmethods at exit from the runtime system") \
399 \
400 notproduct(bool, WalkStackALot, false, \
401 "Trace stack (no print) at every exit from the runtime system") \
402 \
403 develop(bool, DeoptimizeObjectsALot, false, \
404 "For testing purposes concurrent threads revert optimizations " \
405 "based on escape analysis at intervals given with " \
406 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
407 "with DeoptimizeObjectsALotThreadCountSingle and " \
408 "DeoptimizeObjectsALotThreadCountAll.") \
409 \
410 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
411 "Interval for DeoptimizeObjectsALot.") \
412 range(0, max_jlong) \
413 \
414 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
415 "The number of threads that revert optimizations based on " \
416 "escape analysis for a single thread if DeoptimizeObjectsALot " \
417 "is enabled. The target thread is selected round robin." ) \
418 range(0, max_jint) \
419 \
420 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
421 "The number of threads that revert optimizations based on " \
422 "escape analysis for all threads if DeoptimizeObjectsALot " \
423 "is enabled." ) \
424 range(0, max_jint) \
425 \
426 notproduct(bool, VerifyLastFrame, false, \
427 "Verify oops on last frame on entry to VM") \
428 \
429 product(bool, SafepointTimeout, false, \
430 "Time out and warn or fail after SafepointTimeoutDelay " \
431 "milliseconds if failed to reach safepoint") \
432 \
433 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
434 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
435 \
436 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
437 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
438 range(0, max_jlong) \
439 \
440 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
441 "Abort upon failure to complete VM operation promptly") \
442 \
443 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
444 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
445 range(0, max_intx) \
446 \
447 product(bool, MaxFDLimit, true, \
448 "Bump the number of file descriptors to maximum (Unix only)") \
449 \
450 product(bool, LogEvents, true, DIAGNOSTIC, \
451 "Enable the various ring buffer event logs") \
452 \
453 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
454 "Number of ring buffer event logs") \
455 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
456 \
457 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
458 "Enable the Java bytecode verifier for remote classes") \
459 \
460 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
461 "Enable the Java bytecode verifier for local classes") \
462 \
463 develop(bool, VerifyStackAtCalls, false, \
464 "Verify that the stack pointer is unchanged after calls") \
465 \
466 develop(bool, TraceJavaAssertions, false, \
467 "Trace java language assertions") \
468 \
469 notproduct(bool, VerifyCodeCache, false, \
470 "Verify code cache on memory allocation/deallocation") \
471 \
472 develop(bool, ZapResourceArea, trueInDebug, \
473 "Zap freed resource/arena space") \
474 \
475 notproduct(bool, ZapVMHandleArea, trueInDebug, \
476 "Zap freed VM handle space") \
477 \
478 notproduct(bool, ZapStackSegments, trueInDebug, \
479 "Zap allocated/freed stack segments") \
480 \
481 develop(bool, ZapUnusedHeapArea, trueInDebug, \
482 "Zap unused heap space") \
483 \
484 develop(bool, CheckZapUnusedHeapArea, false, \
485 "Check zapping of unused heap space") \
486 \
487 develop(bool, ZapFillerObjects, trueInDebug, \
488 "Zap filler objects") \
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, 17) \
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 \
551 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
552 "Dump heap to file after any major stop-the-world GC") \
553 \
554 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
555 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
556 "from JVM") \
557 \
558 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
559 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \
560 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
561 "in the working directory)") \
562 \
563 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
564 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \
565 "level of the dump file. 0 (the default) disables gzip " \
566 "compression. Otherwise the level must be between 1 and 9.") \
567 range(0, 9) \
568 \
569 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
570 "Native memory tracking options") \
571 \
572 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
573 "Print native memory tracking summary data if it is on") \
574 \
575 product(bool, LogCompilation, false, DIAGNOSTIC, \
576 "Log compilation activity in detail to LogFile") \
577 \
578 product(bool, PrintCompilation, false, \
579 "Print compilations") \
580 \
581 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
582 "Repeat compilation without installing code (number of times)") \
583 range(0, max_jint) \
584 \
585 product(bool, PrintExtendedThreadInfo, false, \
586 "Print more information in thread dump") \
587 \
588 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
589 "0: do not allow scavengable oops in the code cache; " \
590 "1: allow scavenging from the code cache; " \
591 "2: emit as many constants as the compiler can see") \
592 range(0, 2) \
593 \
594 product(bool, AlwaysRestoreFPU, false, \
595 "Restore the FPU control word after every JNI call (expensive)") \
596 \
597 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
598 "Print additional statistics per compilation") \
599 \
600 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
601 "Print code generated for i2c/c2i adapters") \
602 \
603 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
604 "Verify that i2c/c2i adapters are called properly") \
605 \
606 develop(bool, VerifyAdapterSharing, false, \
607 "Verify that the code for shared adapters is the equivalent") \
608 \
609 product(bool, PrintAssembly, false, DIAGNOSTIC, \
610 "Print assembly code (using external disassembler.so)") \
611 \
612 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
613 "Print options string passed to disassembler.so") \
614 \
615 notproduct(bool, PrintNMethodStatistics, false, \
616 "Print a summary statistic for the generated nmethods") \
617 \
618 product(bool, PrintNMethods, false, DIAGNOSTIC, \
619 "Print assembly code for nmethods when generated") \
620 \
621 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
622 "Print assembly code for native nmethods when generated") \
623 \
624 develop(bool, PrintDebugInfo, false, \
625 "Print debug information for all nmethods when generated") \
626 \
627 develop(bool, PrintRelocations, false, \
628 "Print relocation information for all nmethods when generated") \
629 \
630 develop(bool, PrintDependencies, false, \
631 "Print dependency information for all nmethods when generated") \
632 \
633 develop(bool, PrintExceptionHandlers, false, \
634 "Print exception handler tables for all nmethods when generated") \
635 \
636 develop(bool, StressCompiledExceptionHandlers, false, \
637 "Exercise compiled exception handlers") \
638 \
639 develop(bool, InterceptOSException, false, \
640 "Start debugger when an implicit OS (e.g. null pointer) " \
641 "exception happens") \
642 \
643 product(bool, PrintCodeCache, false, \
644 "Print the code cache memory usage when exiting") \
645 \
646 develop(bool, PrintCodeCache2, false, \
647 "Print detailed usage information on the code cache when exiting")\
648 \
649 product(bool, PrintCodeCacheOnCompilation, false, \
650 "Print the code cache memory usage each time a method is " \
651 "compiled") \
652 \
653 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
654 "Print code heap usage statistics on exit and on full condition") \
655 \
656 product(bool, PrintStubCode, false, DIAGNOSTIC, \
657 "Print generated stub code") \
658 \
659 product(bool, StackTraceInThrowable, true, \
660 "Collect backtrace in throwable when exception happens") \
661 \
662 product(bool, OmitStackTraceInFastThrow, true, \
663 "Omit backtraces for some 'hot' exceptions in optimized code") \
664 \
665 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
666 "Show exception messages from RuntimeExceptions that contain " \
667 "snippets of the failing code. Disable this to improve privacy.") \
668 \
669 product(bool, PrintWarnings, true, \
670 "Print JVM warnings to output stream") \
671 \
672 product(bool, RegisterFinalizersAtInit, true, \
673 "(Deprecated) Register finalizable objects at end of " \
674 "Object.<init> or after allocation") \
675 \
676 develop(bool, RegisterReferences, true, \
677 "Tell whether the VM should register soft/weak/final/phantom " \
678 "references") \
679 \
680 develop(bool, PrintCodeCacheExtension, false, \
681 "Print extension of code cache") \
682 \
683 develop(bool, UsePrivilegedStack, true, \
684 "Enable the security JVM functions") \
685 \
686 product(bool, ClassUnloading, true, \
687 "Do unloading of classes") \
688 \
689 product(bool, ClassUnloadingWithConcurrentMark, true, \
690 "Do unloading of classes with a concurrent marking cycle") \
691 \
692 notproduct(bool, PrintSystemDictionaryAtExit, false, \
693 "Print the system dictionary at exit") \
694 \
695 notproduct(bool, PrintClassLoaderDataGraphAtExit, false, \
696 "Print the class loader data graph at exit") \
697 \
698 product(bool, AllowParallelDefineClass, false, \
699 "Allow parallel defineClass requests for class loaders " \
700 "registering as parallel capable") \
701 \
702 product_pd(bool, DontYieldALot, \
703 "Throw away obvious excess yield calls") \
704 \
705 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
706 "Disable the use of stack guard pages if the JVM is loaded " \
707 "on the primordial process thread") \
708 \
709 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
710 "Do JVMTI virtual thread mount/unmount transitions " \
711 "(disabling this flag implies no JVMTI events are posted)") \
712 \
713 /* notice: the max range value here is max_jint, not max_intx */ \
714 /* because of overflow issue */ \
715 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
716 "Async deflate idle monitors every so many milliseconds when " \
717 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
718 range(0, max_jint) \
719 \
720 /* notice: the max range value here is max_jint, not max_intx */ \
721 /* because of overflow issue */ \
722 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
723 "Async deflate idle monitors every so many milliseconds even " \
724 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
725 range(0, max_jint) \
726 \
727 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
728 "Used to estimate a variable ceiling based on number of threads " \
729 "for use with MonitorUsedDeflationThreshold (0 is off).") \
730 range(0, max_uintx) \
731 \
732 /* notice: the max range value here is max_jint, not max_intx */ \
733 /* because of overflow issue */ \
734 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
735 "The maximum number of monitors to deflate, unlink and delete " \
736 "at one time (minimum is 1024).") \
737 range(1024, max_jint) \
738 \
739 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
740 "The maximum number of monitors to unlink in one batch. ") \
741 range(1, max_jint) \
742 \
743 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
744 "Percentage of used monitors before triggering deflation (0 is " \
745 "off). The check is performed on GuaranteedSafepointInterval, " \
746 "AsyncDeflationInterval or GuaranteedAsyncDeflationInterval, " \
747 "whichever is lower.") \
748 range(0, 100) \
749 \
750 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
751 "Max number of no progress async deflation attempts to tolerate " \
752 "before adjusting the in_use_list_ceiling up (0 is off).") \
753 range(0, max_uintx) \
754 \
755 product(intx, hashCode, 5, EXPERIMENTAL, \
756 "(Unstable) select hashCode generation algorithm") \
757 \
758 product(bool, ReduceSignalUsage, false, \
759 "Reduce the use of OS signals in Java and/or the VM") \
760 \
761 develop(bool, LoadLineNumberTables, true, \
762 "Tell whether the class file parser loads line number tables") \
763 \
764 develop(bool, LoadLocalVariableTables, true, \
765 "Tell whether the class file parser loads local variable tables") \
766 \
767 develop(bool, LoadLocalVariableTypeTables, true, \
768 "Tell whether the class file parser loads local variable type" \
769 "tables") \
770 \
771 product(bool, AllowUserSignalHandlers, false, \
772 "Application will install primary signal handlers for the JVM " \
773 "(Unix only)") \
774 \
775 product(bool, UseSignalChaining, true, \
776 "Use signal-chaining to invoke signal handlers installed " \
777 "by the application (Unix only)") \
778 \
779 product(bool, RestoreMXCSROnJNICalls, false, \
780 "Restore MXCSR when returning from JNI calls") \
781 \
782 product(bool, CheckJNICalls, false, \
783 "Verify all arguments to JNI calls") \
784 \
785 product(bool, UseFastJNIAccessors, true, \
786 "Use optimized versions of Get<Primitive>Field") \
787 \
788 product(intx, MaxJNILocalCapacity, 65536, \
789 "Maximum allowable local JNI handle capacity to " \
790 "EnsureLocalCapacity() and PushLocalFrame(), " \
791 "where <= 0 is unlimited, default: 65536") \
792 range(min_intx, max_intx) \
793 \
794 product(bool, EagerXrunInit, false, \
795 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
796 "but not all -Xrun libraries may support the state of the VM " \
797 "at this time") \
798 \
799 product(bool, PreserveAllAnnotations, false, \
800 "Preserve RuntimeInvisibleAnnotations as well " \
801 "as RuntimeVisibleAnnotations") \
802 \
803 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
804 "Number of OutOfMemoryErrors preallocated with backtrace") \
805 \
806 product(bool, UseXMMForArrayCopy, false, \
807 "Use SSE2 MOVQ instruction for Arraycopy") \
808 \
809 notproduct(bool, PrintFieldLayout, false, \
810 "Print field layout for each class") \
811 \
812 notproduct(bool, PrintInlineLayout, false, \
813 "Print field layout for each inline type") \
814 \
815 notproduct(bool, PrintFlatArrayLayout, false, \
816 "Print array layout for each inline type array") \
817 \
818 product(intx, FlatArrayElementMaxSize, -1, \
819 "Max size for flattening inline array elements, <0 no limit") \
820 \
821 product(intx, InlineFieldMaxFlatSize, 128, \
822 "Max size for flattening inline type fields, <0 no limit") \
823 \
824 product(intx, FlatArrayElementMaxOops, 4, \
825 "Max nof embedded object references in an inline type to flatten, <0 no limit") \
826 \
827 product(bool, InlineArrayAtomicAccess, false, \
828 "Atomic inline array accesses by-default, for all inline arrays") \
829 \
830 /* Need to limit the extent of the padding to reasonable size. */\
831 /* 8K is well beyond the reasonable HW cache line size, even with */\
832 /* aggressive prefetching, while still leaving the room for segregating */\
833 /* among the distinct pages. */\
834 product(int, ContendedPaddingWidth, 128, \
835 "How many bytes to pad the fields/classes marked @Contended with")\
836 range(0, 8192) \
837 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
838 \
839 product(bool, EnableContended, true, \
840 "Enable @Contended annotation support") \
841 \
842 product(bool, RestrictContended, true, \
843 "Restrict @Contended to trusted classes") \
844 \
845 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
846 "Detect and take action upon identifying synchronization on " \
847 "value based classes. Modes: " \
848 "0: off; " \
849 "1: exit with fatal error; " \
850 "2: log message to stdout. Output file can be specified with " \
851 " -Xlog:valuebasedclasses. If JFR is running it will " \
852 " also generate JFR events.") \
853 range(0, 2) \
854 \
855 product(bool, ExitOnOutOfMemoryError, false, \
856 "JVM exits on the first occurrence of an out-of-memory error " \
857 "thrown from JVM") \
858 \
859 product(bool, CrashOnOutOfMemoryError, false, \
860 "JVM aborts, producing an error log and core/mini dump, on the " \
861 "first occurrence of an out-of-memory error thrown from JVM") \
862 \
863 product(intx, UserThreadWaitAttemptsAtExit, 30, \
864 "The number of times to wait for user threads to stop executing " \
865 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
866 "The maximum number of waits is 1000, to wait at most 10 " \
867 "seconds.") \
868 range(0, 1000) \
869 \
870 /* tracing */ \
871 \
872 develop(bool, StressRewriter, false, \
873 "Stress linktime bytecode rewriting") \
874 \
875 product(ccstr, TraceJVMTI, nullptr, \
876 "Trace flags for JVMTI functions and events") \
877 \
878 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
879 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
880 "This option can change an EMCP method into an obsolete method " \
881 "and can affect tests that expect specific methods to be EMCP. " \
882 "This option should be used with caution.") \
883 \
884 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
885 "(Deprecated) Allow redefinition to add and delete private " \
886 "static or final methods for compatibility with old releases") \
887 \
888 develop(bool, TraceBytecodes, false, \
889 "Trace bytecode execution") \
890 \
891 develop(bool, TraceICs, false, \
892 "Trace inline cache changes") \
893 \
894 notproduct(bool, TraceInvocationCounterOverflow, false, \
895 "Trace method invocation counter overflow") \
896 \
897 develop(bool, TraceInlineCacheClearing, false, \
898 "Trace clearing of inline caches in nmethods") \
899 \
900 develop(bool, VerifyDependencies, trueInDebug, \
901 "Exercise and verify the compilation dependency mechanism") \
902 \
903 develop(bool, TraceNewOopMapGeneration, false, \
904 "Trace OopMapGeneration") \
905 \
906 develop(bool, TraceNewOopMapGenerationDetailed, false, \
907 "Trace OopMapGeneration: print detailed cell states") \
908 \
909 develop(bool, TimeOopMap, false, \
910 "Time calls to GenerateOopMap::compute_map() in sum") \
911 \
912 develop(bool, TimeOopMap2, false, \
913 "Time calls to GenerateOopMap::compute_map() individually") \
914 \
915 develop(bool, TraceOopMapRewrites, false, \
916 "Trace rewriting of methods during oop map generation") \
917 \
918 develop(bool, TraceICBuffer, false, \
919 "Trace usage of IC buffer") \
920 \
921 develop(bool, TraceCompiledIC, false, \
922 "Trace changes of compiled IC") \
923 \
924 develop(bool, FLSVerifyDictionary, false, \
925 "Do lots of (expensive) FLS dictionary verification") \
926 \
927 product(uintx, ProcessDistributionStride, 4, \
928 "Stride through processors when distributing processes") \
929 range(0, max_juint) \
930 \
931 develop(bool, TraceFinalizerRegistration, false, \
932 "Trace registration of final references") \
933 \
934 product(bool, IgnoreEmptyClassPaths, false, \
935 "Ignore empty path elements in -classpath") \
936 \
937 product(bool, PrintHeapAtSIGBREAK, true, \
938 "Print heap layout in response to SIGBREAK") \
939 \
940 product(bool, PrintClassHistogram, false, MANAGEABLE, \
941 "Print a histogram of class instances") \
942 \
943 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
944 "The percentage of the used heap that the instances of a class " \
945 "must occupy for the class to generate a trace event") \
946 range(0.0, 100.0) \
947 \
948 /* JVMTI heap profiling */ \
949 \
950 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
951 "Verify memory system before JVMTI iteration") \
952 \
953 /* compiler */ \
954 \
955 /* notice: the max range value here is max_jint, not max_intx */ \
956 /* because of overflow issue */ \
957 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
958 "Number of compiler threads to run") \
959 range(0, max_jint) \
960 constraint(CICompilerCountConstraintFunc, AfterErgo) \
961 \
962 product(bool, UseDynamicNumberOfCompilerThreads, true, \
963 "Dynamically choose the number of parallel compiler threads") \
964 \
965 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
966 "Reduce the number of parallel compiler threads when they " \
967 "are not used") \
968 \
969 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
970 "Trace creation and removal of compiler threads") \
971 \
972 product(ccstr, LogClassLoadingCauseFor, nullptr, \
973 "Apply -Xlog:class+load+cause* to classes whose fully " \
974 "qualified name contains this string (\"*\" matches " \
975 "any class).") \
976 \
977 develop(bool, InjectCompilerCreationFailure, false, \
978 "Inject thread creation failures for " \
979 "UseDynamicNumberOfCompilerThreads") \
980 \
981 develop(bool, GenerateSynchronizationCode, true, \
982 "generate locking/unlocking code for synchronized methods and " \
983 "monitors") \
984 \
985 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
986 "Generate code for implicit null checks") \
987 \
988 product_pd(bool, TrapBasedNullChecks, \
989 "Generate code for null checks that uses a cmp and trap " \
990 "instruction raising SIGTRAP. This is only used if an access to" \
991 "null (+offset) will not raise a SIGSEGV, i.e.," \
992 "ImplicitNullChecks don't work (PPC64).") \
993 \
994 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
995 "Enable Thread SMR Statistics") \
996 \
997 product(bool, UseNotificationThread, true, \
998 "Use Notification Thread") \
999 \
1000 product(bool, Inline, true, \
1001 "Enable inlining") \
1002 \
1003 product(bool, ClipInlining, true, \
1004 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
1005 \
1006 develop(bool, UseCHA, true, \
1007 "Enable CHA") \
1008 \
1009 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \
1010 "Use vtable information during CHA") \
1011 \
1012 product(bool, UseTypeProfile, true, \
1013 "Check interpreter profile for historically monomorphic calls") \
1014 \
1015 product(bool, PrintInlining, false, DIAGNOSTIC, \
1016 "Print inlining optimizations") \
1017 \
1018 product(bool, UsePopCountInstruction, false, \
1019 "Use population count instruction") \
1020 \
1021 develop(bool, TraceMethodReplacement, false, \
1022 "Print when methods are replaced do to recompilation") \
1023 \
1024 product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC, \
1025 "print statistics about method flushing") \
1026 \
1027 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
1028 "Minimum number of sweeper passes before an nmethod " \
1029 "can be flushed") \
1030 range(0, max_intx) \
1031 \
1032 develop(bool, StressCodeBuffers, false, \
1033 "Exercise code buffer expansion and other rare state changes") \
1034 \
1035 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
1036 "Generate extra debugging information for non-safepoints in " \
1037 "nmethods") \
1038 \
1039 product(bool, PrintVMOptions, false, \
1040 "Print flags that appeared on the command line") \
1041 \
1042 product(bool, IgnoreUnrecognizedVMOptions, false, \
1043 "Ignore unrecognized VM options") \
1044 \
1045 product(bool, PrintCommandLineFlags, false, \
1046 "Print flags specified on command line or set by ergonomics") \
1047 \
1048 product(bool, PrintFlagsInitial, false, \
1049 "Print all VM flags before argument processing and exit VM") \
1050 \
1051 product(bool, PrintFlagsFinal, false, \
1052 "Print all VM flags after argument and ergonomic processing") \
1053 \
1054 notproduct(bool, PrintFlagsWithComments, false, \
1055 "Print all VM flags with default values and descriptions and " \
1056 "exit") \
1057 \
1058 product(bool, PrintFlagsRanges, false, \
1059 "Print VM flags and their ranges") \
1060 \
1061 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1062 "Use a mutex to serialize output to tty and LogFile") \
1063 \
1064 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1065 "Display all VM output on the tty, independently of LogVMOutput") \
1066 \
1067 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1068 "Save VM output to LogFile") \
1069 \
1070 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1071 "If LogVMOutput or LogCompilation is on, save VM output to " \
1072 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1073 \
1074 product(ccstr, ErrorFile, nullptr, \
1075 "If an error occurs, save the error data to this file " \
1076 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1077 \
1078 product(bool, ExtensiveErrorReports, \
1079 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1080 "Error reports are more extensive.") \
1081 \
1082 product(bool, DisplayVMOutputToStderr, false, \
1083 "If DisplayVMOutput is true, display all VM output to stderr") \
1084 \
1085 product(bool, DisplayVMOutputToStdout, false, \
1086 "If DisplayVMOutput is true, display all VM output to stdout") \
1087 \
1088 product(bool, ErrorFileToStderr, false, \
1089 "If true, error data is printed to stderr instead of a file") \
1090 \
1091 product(bool, ErrorFileToStdout, false, \
1092 "If true, error data is printed to stdout instead of a file") \
1093 \
1094 develop(bool, VerifyHeavyMonitors, false, \
1095 "Checks that no stack locking happens when using " \
1096 "-XX:LockingMode=0 (LM_MONITOR)") \
1097 \
1098 product(bool, PrintStringTableStatistics, false, \
1099 "print statistics about the StringTable and SymbolTable") \
1100 \
1101 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1102 "verify StringTable contents at exit") \
1103 \
1104 notproduct(bool, PrintSymbolTableSizeHistogram, false, \
1105 "print histogram of the symbol table") \
1106 \
1107 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1108 "Call fatal if this exception is thrown. Example: " \
1109 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1110 \
1111 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1112 "Call fatal if the exception pointed by AbortVMOnException " \
1113 "has this message") \
1114 \
1115 develop(bool, DebugVtables, false, \
1116 "add debugging code to vtable dispatch") \
1117 \
1118 product(bool, RangeCheckElimination, true, \
1119 "Eliminate range checks") \
1120 \
1121 develop_pd(bool, UncommonNullCast, \
1122 "track occurrences of null in casts; adjust compiler tactics") \
1123 \
1124 develop(bool, TypeProfileCasts, true, \
1125 "treat casts like calls for purposes of type profiling") \
1126 \
1127 develop(bool, TraceLivenessGen, false, \
1128 "Trace the generation of liveness analysis information") \
1129 \
1130 notproduct(bool, TraceLivenessQuery, false, \
1131 "Trace queries of liveness analysis information") \
1132 \
1133 notproduct(bool, CollectIndexSetStatistics, false, \
1134 "Collect information about IndexSets") \
1135 \
1136 develop(int, FastAllocateSizeLimit, 128*K, \
1137 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1138 "Inline allocations larger than this in doublewords must go slow")\
1139 \
1140 product_pd(bool, CompactStrings, \
1141 "Enable Strings to use single byte chars in backing store") \
1142 \
1143 product_pd(uint, TypeProfileLevel, \
1144 "=XYZ, with Z: Type profiling of arguments at call; " \
1145 "Y: Type profiling of return value at call; " \
1146 "X: Type profiling of parameters to methods; " \
1147 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1148 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1149 \
1150 product(int, TypeProfileArgsLimit, 2, \
1151 "max number of call arguments to consider for type profiling") \
1152 range(0, 16) \
1153 \
1154 product(int, TypeProfileParmsLimit, 2, \
1155 "max number of incoming parameters to consider for type profiling"\
1156 ", -1 for all") \
1157 range(-1, 64) \
1158 \
1159 /* statistics */ \
1160 develop(bool, CountCompiledCalls, false, \
1161 "Count method invocations") \
1162 \
1163 notproduct(bool, ICMissHistogram, false, \
1164 "Produce histogram of IC misses") \
1165 \
1166 /* interpreter */ \
1167 product_pd(bool, RewriteBytecodes, \
1168 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1169 \
1170 product_pd(bool, RewriteFrequentPairs, \
1171 "Rewrite frequently used bytecode pairs into a single bytecode") \
1172 \
1173 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1174 "Print the generated interpreter code") \
1175 \
1176 product(bool, UseInterpreter, true, \
1177 "Use interpreter for non-compiled methods") \
1178 \
1179 develop(bool, UseFastSignatureHandlers, true, \
1180 "Use fast signature handlers for native calls") \
1181 \
1182 product(bool, UseLoopCounter, true, \
1183 "Increment invocation counter on backward branch") \
1184 \
1185 product_pd(bool, UseOnStackReplacement, \
1186 "Use on stack replacement, calls runtime if invoc. counter " \
1187 "overflows in loop") \
1188 \
1189 notproduct(bool, TraceOnStackReplacement, false, \
1190 "Trace on stack replacement") \
1191 \
1192 product_pd(bool, PreferInterpreterNativeStubs, \
1193 "Use always interpreter stubs for native methods invoked via " \
1194 "interpreter") \
1195 \
1196 develop(bool, CountBytecodes, false, \
1197 "Count number of bytecodes executed") \
1198 \
1199 develop(bool, PrintBytecodeHistogram, false, \
1200 "Print histogram of the executed bytecodes") \
1201 \
1202 develop(bool, PrintBytecodePairHistogram, false, \
1203 "Print histogram of the executed bytecode pairs") \
1204 \
1205 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1206 "Print code generated for native method signature handlers") \
1207 \
1208 develop(bool, VerifyOops, false, \
1209 "Do plausibility checks for oops") \
1210 \
1211 develop(bool, CheckUnhandledOops, false, \
1212 "Check for unhandled oops in VM code") \
1213 \
1214 develop(bool, VerifyJNIFields, trueInDebug, \
1215 "Verify jfieldIDs for instance fields") \
1216 \
1217 develop(bool, VerifyFPU, false, \
1218 "Verify FPU state (check for NaN's, etc.)") \
1219 \
1220 develop(bool, VerifyActivationFrameSize, false, \
1221 "Verify that activation frame didn't become smaller than its " \
1222 "minimal size") \
1223 \
1224 develop(bool, TraceFrequencyInlining, false, \
1225 "Trace frequency based inlining") \
1226 \
1227 develop_pd(bool, InlineIntrinsics, \
1228 "Use intrinsics in Interpreter that can be statically resolved") \
1229 \
1230 product_pd(bool, ProfileInterpreter, \
1231 "Profile at the bytecode level during interpretation") \
1232 \
1233 develop_pd(bool, ProfileTraps, \
1234 "Profile deoptimization traps at the bytecode level") \
1235 \
1236 product(intx, ProfileMaturityPercentage, 20, \
1237 "number of method invocations/branches (expressed as % of " \
1238 "CompileThreshold) before using the method's profile") \
1239 range(0, 100) \
1240 \
1241 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1242 "Print the results of +ProfileInterpreter at end of run") \
1243 \
1244 develop(bool, VerifyDataPointer, trueInDebug, \
1245 "Verify the method data pointer during interpreter profiling") \
1246 \
1247 notproduct(bool, CrashGCForDumpingJavaThread, false, \
1248 "Manually make GC thread crash then dump java stack trace; " \
1249 "Test only") \
1250 \
1251 /* compilation */ \
1252 product(bool, UseCompiler, true, \
1253 "Use Just-In-Time compilation") \
1254 \
1255 develop(intx, CounterHalfLifeTime, 30, \
1256 "Half-life time of invocation counters (in seconds)") \
1257 \
1258 product(bool, AlwaysCompileLoopMethods, false, \
1259 "When using recompilation, never interpret methods " \
1260 "containing loops") \
1261 \
1262 product(int, AllocatePrefetchStyle, 1, \
1263 "0 = no prefetch, " \
1264 "1 = generate prefetch instructions for each allocation, " \
1265 "2 = use TLAB watermark to gate allocation prefetch, " \
1266 "3 = generate one prefetch instruction per cache line") \
1267 range(0, 3) \
1268 \
1269 product(int, AllocatePrefetchDistance, -1, \
1270 "Distance to prefetch ahead of allocation pointer. " \
1271 "-1: use system-specific value (automatically determined") \
1272 range(-1, 512) \
1273 \
1274 product(int, AllocatePrefetchLines, 3, \
1275 "Number of lines to prefetch ahead of array allocation pointer") \
1276 range(1, 64) \
1277 \
1278 product(int, AllocateInstancePrefetchLines, 1, \
1279 "Number of lines to prefetch ahead of instance allocation " \
1280 "pointer") \
1281 range(1, 64) \
1282 \
1283 product(int, AllocatePrefetchStepSize, 16, \
1284 "Step size in bytes of sequential prefetch instructions") \
1285 range(1, 512) \
1286 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1287 \
1288 product(intx, AllocatePrefetchInstr, 0, \
1289 "Select instruction to prefetch ahead of allocation pointer") \
1290 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1291 \
1292 /* deoptimization */ \
1293 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1294 "Trace deoptimization") \
1295 \
1296 develop(bool, PrintDeoptimizationDetails, false, \
1297 "Print more information about deoptimization") \
1298 \
1299 develop(bool, DebugDeoptimization, false, \
1300 "Tracing various information while debugging deoptimization") \
1301 \
1302 product(double, SelfDestructTimer, 0.0, \
1303 "Will cause VM to terminate after a given time " \
1304 "(in fractional minutes) " \
1305 "(0.0 means off)") \
1306 range(0.0, (double)max_intx) \
1307 \
1308 product(int, MaxJavaStackTraceDepth, 1024, \
1309 "The maximum number of lines in the stack trace for Java " \
1310 "exceptions (0 means all)") \
1311 range(0, max_jint/2) \
1312 \
1313 /* notice: the max range value here is max_jint, not max_intx */ \
1314 /* because of overflow issue */ \
1315 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \
1316 "Guarantee a safepoint (at least) every so many milliseconds " \
1317 "(0 means none)") \
1318 range(0, max_jint) \
1319 \
1320 product(double, SafepointTimeoutDelay, 10000, \
1321 "Delay in milliseconds for option SafepointTimeout; " \
1322 "supports sub-millisecond resolution with fractional values.") \
1323 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1324 \
1325 product(bool, UseSystemMemoryBarrier, false, \
1326 "Try to enable system memory barrier if supported by OS") \
1327 \
1328 product(intx, NmethodSweepActivity, 4, \
1329 "Removes cold nmethods from code cache if > 0. Higher values " \
1330 "result in more aggressive sweeping") \
1331 range(0, 2000) \
1332 \
1333 develop(intx, MallocCatchPtr, -1, \
1334 "Hit breakpoint when mallocing/freeing this pointer") \
1335 \
1336 develop(int, StackPrintLimit, 100, \
1337 "number of stack frames to print in VM-level stack dump") \
1338 \
1339 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1340 "max number of compiled code units to print in error log") \
1341 range(0, VMError::max_error_log_print_code) \
1342 \
1343 notproduct(int, MaxElementPrintSize, 256, \
1344 "maximum number of elements to print") \
1345 \
1346 notproduct(intx, MaxSubklassPrintSize, 4, \
1347 "maximum number of subklasses to print when printing klass") \
1348 \
1349 develop(intx, MaxForceInlineLevel, 100, \
1350 "maximum number of nested calls that are forced for inlining " \
1351 "(using CompileCommand or marked w/ @ForceInline)") \
1352 range(0, max_jint) \
1353 \
1354 develop(intx, MethodHistogramCutoff, 100, \
1355 "The cutoff value for method invocation histogram (+CountCalls)") \
1356 \
1357 develop(intx, DontYieldALotInterval, 10, \
1358 "Interval between which yields will be dropped (milliseconds)") \
1359 \
1360 notproduct(intx, DeoptimizeALotInterval, 5, \
1361 "Number of exits until DeoptimizeALot kicks in") \
1362 \
1363 notproduct(intx, ZombieALotInterval, 5, \
1364 "Number of exits until ZombieALot kicks in") \
1365 \
1366 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1367 "Limit malloc allocation size from VM. Reaching a limit will " \
1368 "trigger an action (see flag). This feature requires " \
1369 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1370 "Usage:" \
1371 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1372 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1373 "sets one or more category-specific limits." \
1374 "<flag> defines the action upon reaching the limit:" \
1375 "\"fatal\": end VM with a fatal error at the allocation site" \
1376 "\"oom\" : will mimic a native OOM" \
1377 "If <flag> is omitted, \"fatal\" is the default." \
1378 "Examples:\n" \
1379 "-XX:MallocLimit=2g" \
1380 "-XX:MallocLimit=2g:oom" \
1381 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1382 \
1383 product(intx, TypeProfileWidth, 2, \
1384 "Number of receiver types to record in call/cast profile") \
1385 range(0, 8) \
1386 \
1387 develop(intx, BciProfileWidth, 2, \
1388 "Number of return bci's to record in ret profile") \
1389 \
1390 product(intx, PerMethodRecompilationCutoff, 400, \
1391 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1392 range(-1, max_intx) \
1393 \
1394 product(intx, PerBytecodeRecompilationCutoff, 200, \
1395 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1396 range(-1, max_intx) \
1397 \
1398 product(intx, PerMethodTrapLimit, 100, \
1399 "Limit on traps (of one kind) in a method (includes inlines)") \
1400 range(0, max_jint) \
1401 \
1402 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1403 "Limit on speculative traps (of one kind) in a method " \
1404 "(includes inlines)") \
1405 range(0, max_jint) \
1406 \
1407 product(intx, PerBytecodeTrapLimit, 4, \
1408 "Limit on traps (of one kind) at a particular BCI") \
1409 range(0, max_jint) \
1410 \
1411 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1412 "Extra method data trap entries for speculation") \
1413 \
1414 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1415 "Ratio of call site execution to caller method invocation") \
1416 \
1417 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1418 "Minimum ratio of call site execution to caller method" \
1419 "invocation to be considered for inlining") \
1420 \
1421 develop(intx, InlineThrowCount, 50, \
1422 "Force inlining of interpreted methods that throw this often") \
1423 range(0, max_jint) \
1424 \
1425 develop(intx, InlineThrowMaxSize, 200, \
1426 "Force inlining of throwing methods smaller than this") \
1427 range(0, max_jint) \
1428 \
1429 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1430 "Initial threshold (in bytes) at which a garbage collection " \
1431 "is done to reduce Metaspace usage") \
1432 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1433 \
1434 product(size_t, MaxMetaspaceSize, max_uintx, \
1435 "Maximum size of Metaspaces (in bytes)") \
1436 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1437 \
1438 product(size_t, CompressedClassSpaceSize, 1*G, \
1439 "Maximum size of class area in Metaspace when compressed " \
1440 "class pointers are used") \
1441 range(1*M, 3*G) \
1442 \
1443 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1444 "Force the class space to be allocated at this address or " \
1445 "fails VM initialization (requires -Xshare=off.") \
1446 \
1447 develop(bool, RandomizeClassSpaceLocation, true, \
1448 "Randomize location of class space.") \
1449 \
1450 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1451 "Print metaspace statistics upon VM exit.") \
1452 \
1453 develop(bool, MetaspaceGuardAllocations, false, \
1454 "Metapace allocations are guarded.") \
1455 \
1456 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1457 "The minimum percentage of heap free after GC to avoid expansion."\
1458 " For most GCs this applies to the old generation. In G1 and" \
1459 " ParallelGC it applies to the whole heap.") \
1460 range(0, 100) \
1461 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1462 \
1463 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1464 "The maximum percentage of heap free after GC to avoid shrinking."\
1465 " For most GCs this applies to the old generation. In G1 and" \
1466 " ParallelGC it applies to the whole heap.") \
1467 range(0, 100) \
1468 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1469 \
1470 product(bool, ShrinkHeapInSteps, true, \
1471 "When disabled, informs the GC to shrink the java heap directly" \
1472 " to the target size at the next full GC rather than requiring" \
1473 " smaller steps during multiple full GCs.") \
1474 \
1475 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1476 "Number of milliseconds per MB of free space in the heap") \
1477 range(0, max_intx) \
1478 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1479 \
1480 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1481 "The minimum change in heap space due to GC (in bytes)") \
1482 range(0, max_uintx) \
1483 \
1484 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1485 "The minimum expansion of Metaspace (in bytes)") \
1486 range(0, max_uintx) \
1487 \
1488 product(uint, MaxMetaspaceFreeRatio, 70, \
1489 "The maximum percentage of Metaspace free after GC to avoid " \
1490 "shrinking") \
1491 range(0, 100) \
1492 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1493 \
1494 product(uint, MinMetaspaceFreeRatio, 40, \
1495 "The minimum percentage of Metaspace free after GC to avoid " \
1496 "expansion") \
1497 range(0, 99) \
1498 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1499 \
1500 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1501 "The maximum expansion of Metaspace without full GC (in bytes)") \
1502 range(0, max_uintx) \
1503 \
1504 /* stack parameters */ \
1505 product_pd(intx, StackYellowPages, \
1506 "Number of yellow zone (recoverable overflows) pages of size " \
1507 "4KB. If pages are bigger yellow zone is aligned up.") \
1508 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1509 \
1510 product_pd(intx, StackRedPages, \
1511 "Number of red zone (unrecoverable overflows) pages of size " \
1512 "4KB. If pages are bigger red zone is aligned up.") \
1513 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1514 \
1515 product_pd(intx, StackReservedPages, \
1516 "Number of reserved zone (reserved to annotated methods) pages" \
1517 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1518 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1519 \
1520 product(bool, RestrictReservedStack, true, \
1521 "Restrict @ReservedStackAccess to trusted classes") \
1522 \
1523 /* greater stack shadow pages can't generate instruction to bang stack */ \
1524 product_pd(intx, StackShadowPages, \
1525 "Number of shadow zone (for overflow checking) pages of size " \
1526 "4KB. If pages are bigger shadow zone is aligned up. " \
1527 "This should exceed the depth of the VM and native call stack.") \
1528 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1529 \
1530 product_pd(intx, ThreadStackSize, \
1531 "Thread Stack Size (in Kbytes)") \
1532 range(0, 1 * M) \
1533 \
1534 product_pd(intx, VMThreadStackSize, \
1535 "Non-Java Thread Stack Size (in Kbytes)") \
1536 range(0, max_intx/(1 * K)) \
1537 \
1538 product_pd(intx, CompilerThreadStackSize, \
1539 "Compiler Thread Stack Size (in Kbytes)") \
1540 range(0, max_intx/(1 * K)) \
1541 \
1542 develop_pd(size_t, JVMInvokeMethodSlack, \
1543 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1544 \
1545 /* code cache parameters */ \
1546 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1547 "Code cache segment size (in bytes) - smallest unit of " \
1548 "allocation") \
1549 range(1, 1024) \
1550 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1551 \
1552 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1553 "Code entry alignment for generated code (in bytes)") \
1554 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1555 \
1556 product_pd(intx, OptoLoopAlignment, \
1557 "Align inner loops to zero relative to this modulus") \
1558 range(1, 128) \
1559 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1560 \
1561 product_pd(uintx, InitialCodeCacheSize, \
1562 "Initial code cache size (in bytes)") \
1563 constraint(VMPageSizeConstraintFunc, AtParse) \
1564 \
1565 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1566 "Minimum code cache size (in bytes) required to start VM.") \
1567 range(0, max_uintx) \
1568 \
1569 product(bool, SegmentedCodeCache, false, \
1570 "Use a segmented code cache") \
1571 \
1572 product_pd(uintx, ReservedCodeCacheSize, \
1573 "Reserved code cache size (in bytes) - maximum code cache size") \
1574 constraint(VMPageSizeConstraintFunc, AtParse) \
1575 \
1576 product_pd(uintx, NonProfiledCodeHeapSize, \
1577 "Size of code heap with non-profiled methods (in bytes)") \
1578 range(0, max_uintx) \
1579 \
1580 product_pd(uintx, ProfiledCodeHeapSize, \
1581 "Size of code heap with profiled methods (in bytes)") \
1582 range(0, max_uintx) \
1583 \
1584 product_pd(uintx, NonNMethodCodeHeapSize, \
1585 "Size of code heap with non-nmethods (in bytes)") \
1586 constraint(VMPageSizeConstraintFunc, AtParse) \
1587 \
1588 product_pd(uintx, CodeCacheExpansionSize, \
1589 "Code cache expansion size (in bytes)") \
1590 range(32*K, max_uintx) \
1591 \
1592 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1593 "Minimum number of segments in a code cache block") \
1594 range(1, 100) \
1595 \
1596 notproduct(bool, ExitOnFullCodeCache, false, \
1597 "Exit the VM if we fill the code cache") \
1598 \
1599 product(bool, UseCodeCacheFlushing, true, \
1600 "Remove cold/old nmethods from the code cache") \
1601 \
1602 product(double, SweeperThreshold, 15.0, \
1603 "Threshold when a code cache unloading GC is invoked." \
1604 "Value is percentage of ReservedCodeCacheSize.") \
1605 range(0.0, 100.0) \
1606 \
1607 product(uintx, StartAggressiveSweepingAt, 10, \
1608 "Start aggressive sweeping if X[%] of the code cache is free." \
1609 "Segmented code cache: X[%] of the non-profiled heap." \
1610 "Non-segmented code cache: X[%] of the total code cache") \
1611 range(0, 100) \
1612 \
1613 /* interpreter debugging */ \
1614 develop(intx, BinarySwitchThreshold, 5, \
1615 "Minimal number of lookupswitch entries for rewriting to binary " \
1616 "switch") \
1617 \
1618 develop(intx, StopInterpreterAt, 0, \
1619 "Stop interpreter execution at specified bytecode number") \
1620 \
1621 develop(intx, TraceBytecodesAt, 0, \
1622 "Trace bytecodes starting with specified bytecode number") \
1623 \
1624 develop(intx, TraceBytecodesStopAt, 0, \
1625 "Stop bytecode tracing at the specified bytecode number") \
1626 \
1627 /* Priorities */ \
1628 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1629 \
1630 product(int, ThreadPriorityPolicy, 0, \
1631 "0 : Normal. "\
1632 " VM chooses priorities that are appropriate for normal "\
1633 " applications. "\
1634 " On Windows applications are allowed to use higher native "\
1635 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1636 " not use the highest possible native priority, "\
1637 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1638 " system threads. On Linux thread priorities are ignored "\
1639 " because the OS does not support static priority in "\
1640 " SCHED_OTHER scheduling class which is the only choice for "\
1641 " non-root, non-realtime applications. "\
1642 "1 : Aggressive. "\
1643 " Java thread priorities map over to the entire range of "\
1644 " native thread priorities. Higher Java thread priorities map "\
1645 " to higher native thread priorities. This policy should be "\
1646 " used with care, as sometimes it can cause performance "\
1647 " degradation in the application and/or the entire system. On "\
1648 " Linux/BSD/macOS this policy requires root privilege or an "\
1649 " extended capability.") \
1650 range(0, 1) \
1651 \
1652 product(bool, ThreadPriorityVerbose, false, \
1653 "Print priority changes") \
1654 \
1655 product(int, CompilerThreadPriority, -1, \
1656 "The native priority at which compiler threads should run " \
1657 "(-1 means no change)") \
1658 range(min_jint, max_jint) \
1659 \
1660 product(int, VMThreadPriority, -1, \
1661 "The native priority at which the VM thread should run " \
1662 "(-1 means no change)") \
1663 range(-1, 127) \
1664 \
1665 product(int, JavaPriority1_To_OSPriority, -1, \
1666 "Map Java priorities to OS priorities") \
1667 range(-1, 127) \
1668 \
1669 product(int, JavaPriority2_To_OSPriority, -1, \
1670 "Map Java priorities to OS priorities") \
1671 range(-1, 127) \
1672 \
1673 product(int, JavaPriority3_To_OSPriority, -1, \
1674 "Map Java priorities to OS priorities") \
1675 range(-1, 127) \
1676 \
1677 product(int, JavaPriority4_To_OSPriority, -1, \
1678 "Map Java priorities to OS priorities") \
1679 range(-1, 127) \
1680 \
1681 product(int, JavaPriority5_To_OSPriority, -1, \
1682 "Map Java priorities to OS priorities") \
1683 range(-1, 127) \
1684 \
1685 product(int, JavaPriority6_To_OSPriority, -1, \
1686 "Map Java priorities to OS priorities") \
1687 range(-1, 127) \
1688 \
1689 product(int, JavaPriority7_To_OSPriority, -1, \
1690 "Map Java priorities to OS priorities") \
1691 range(-1, 127) \
1692 \
1693 product(int, JavaPriority8_To_OSPriority, -1, \
1694 "Map Java priorities to OS priorities") \
1695 range(-1, 127) \
1696 \
1697 product(int, JavaPriority9_To_OSPriority, -1, \
1698 "Map Java priorities to OS priorities") \
1699 range(-1, 127) \
1700 \
1701 product(int, JavaPriority10_To_OSPriority,-1, \
1702 "Map Java priorities to OS priorities") \
1703 range(-1, 127) \
1704 \
1705 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1706 "Java thread priority 10 maps to critical scheduling priority") \
1707 \
1708 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1709 "Compiler thread(s) run at critical scheduling priority") \
1710 \
1711 develop(intx, NewCodeParameter, 0, \
1712 "Testing Only: Create a dedicated integer parameter before " \
1713 "putback") \
1714 \
1715 /* new oopmap storage allocation */ \
1716 develop(intx, MinOopMapAllocation, 8, \
1717 "Minimum number of OopMap entries in an OopMapSet") \
1718 \
1719 /* recompilation */ \
1720 product_pd(intx, CompileThreshold, \
1721 "number of interpreted method invocations before (re-)compiling") \
1722 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1723 \
1724 product_pd(bool, TieredCompilation, \
1725 "Enable tiered compilation") \
1726 \
1727 /* Properties for Java libraries */ \
1728 \
1729 product(uint64_t, MaxDirectMemorySize, 0, \
1730 "Maximum total size of NIO direct-buffer allocations. " \
1731 "Ignored if not explicitly set.") \
1732 range(0, max_jlong) \
1733 \
1734 /* Flags used for temporary code during development */ \
1735 \
1736 product(bool, UseNewCode, false, DIAGNOSTIC, \
1737 "Testing Only: Use the new version while testing") \
1738 \
1739 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1740 "Testing Only: Use the new version while testing") \
1741 \
1742 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1743 "Testing Only: Use the new version while testing") \
1744 \
1745 notproduct(bool, UseDebuggerErgo, false, \
1746 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1747 "Turns on the other UseDebuggerErgo* flags") \
1748 \
1749 notproduct(bool, UseDebuggerErgo1, false, \
1750 "Debugging Only: Enable workarounds for debugger induced " \
1751 "os::processor_id() >= os::processor_count() problems") \
1752 \
1753 notproduct(bool, UseDebuggerErgo2, false, \
1754 "Debugging Only: Limit the number of spawned JVM threads") \
1755 \
1756 notproduct(bool, EnableJVMTIStackDepthAsserts, true, \
1757 "Enable JVMTI asserts related to stack depth checks") \
1758 \
1759 /* flags for performance data collection */ \
1760 \
1761 product(bool, UsePerfData, true, \
1762 "Flag to disable jvmstat instrumentation for performance testing "\
1763 "and problem isolation purposes") \
1764 \
1765 product(bool, PerfDataSaveToFile, false, \
1766 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1767 \
1768 product(ccstr, PerfDataSaveFile, nullptr, \
1769 "Save PerfData memory to the specified absolute pathname. " \
1770 "The string %p in the file name (if present) " \
1771 "will be replaced by pid") \
1772 \
1773 product(int, PerfDataSamplingInterval, 50, \
1774 "Data sampling interval (in milliseconds)") \
1775 range(PeriodicTask::min_interval, max_jint) \
1776 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1777 \
1778 product(bool, PerfDisableSharedMem, false, \
1779 "Store performance data in standard memory") \
1780 \
1781 product(int, PerfDataMemorySize, 32*K, \
1782 "Size of performance data memory region. Will be rounded " \
1783 "up to a multiple of the native os page size.") \
1784 range(128, 32*64*K) \
1785 \
1786 product(int, PerfMaxStringConstLength, 1024, \
1787 "Maximum PerfStringConstant string length before truncation") \
1788 range(32, 32*K) \
1789 \
1790 product(bool, PerfAllowAtExitRegistration, false, \
1791 "Allow registration of atexit() methods") \
1792 \
1793 product(bool, PerfBypassFileSystemCheck, false, \
1794 "Bypass Win32 file system criteria checks (Windows Only)") \
1795 \
1796 product(int, UnguardOnExecutionViolation, 0, \
1797 "Unguard page and retry on no-execute fault (Win32 only) " \
1798 "0=off, 1=conservative, 2=aggressive") \
1799 range(0, 2) \
1800 \
1801 /* Serviceability Support */ \
1802 \
1803 product(bool, ManagementServer, false, \
1804 "Create JMX Management Server") \
1805 \
1806 product(bool, DisableAttachMechanism, false, \
1807 "Disable mechanism that allows tools to attach to this VM") \
1808 \
1809 product(bool, StartAttachListener, false, \
1810 "Always start Attach Listener at VM startup") \
1811 \
1812 product(bool, EnableDynamicAgentLoading, true, \
1813 "Allow tools to load agents with the attach mechanism") \
1814 \
1815 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1816 "Print java.util.concurrent locks in thread dump") \
1817 \
1818 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1819 "Print generated stub code for method handles") \
1820 \
1821 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1822 "perform extra checks when constructing method handles") \
1823 \
1824 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1825 "show method handle implementation frames (usually hidden)") \
1826 \
1827 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1828 "show virtual threads' carrier frames in exceptions") \
1829 \
1830 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1831 "trust final non-static declarations for constant folding") \
1832 \
1833 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1834 "Optimize loads from stable fields (marked w/ @Stable)") \
1835 \
1836 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1837 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1838 "resolved before the bootstrap method is called; 1: when a BSM " \
1839 "that may accept a BootstrapCallInfo is detected, use that API " \
1840 "to pass BSM arguments, which allows the BSM to delay their " \
1841 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1842 "via that API, instead of with the eagerly-resolved array.") \
1843 \
1844 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1845 "Causes the VM to pause at startup time and wait for the pause " \
1846 "file to be removed (default: ./vm.paused.<pid>)") \
1847 \
1848 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1849 "The file to create and for whose removal to await when pausing " \
1850 "at startup. (default: ./vm.paused.<pid>)") \
1851 \
1852 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1853 "Pause and wait for keypress on exit if a debugger is attached") \
1854 \
1855 product(bool, DTraceMethodProbes, false, \
1856 "Enable dtrace tool probes for method-entry and method-exit") \
1857 \
1858 product(bool, DTraceAllocProbes, false, \
1859 "Enable dtrace tool probes for object allocation") \
1860 \
1861 product(bool, DTraceMonitorProbes, false, \
1862 "Enable dtrace tool probes for monitor events") \
1863 \
1864 product(bool, RelaxAccessControlCheck, false, \
1865 "Relax the access control checks in the verifier") \
1866 \
1867 product(uintx, StringTableSize, defaultStringTableSize, \
1868 "Number of buckets in the interned String table " \
1869 "(will be rounded to nearest higher power of 2)") \
1870 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1871 \
1872 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1873 "Number of buckets in the JVM internal Symbol table") \
1874 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1875 \
1876 product(bool, UseStringDeduplication, false, \
1877 "Use string deduplication") \
1878 \
1879 product(uint, StringDeduplicationAgeThreshold, 3, \
1880 "A string must reach this age (or be promoted to an old region) " \
1881 "to be considered for deduplication") \
1882 range(1, markWord::max_age) \
1883 \
1884 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1885 "Approximate initial number of buckets in the table") \
1886 range(1, 1 * G) \
1887 \
1888 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1889 "Entries per bucket above which the table should be expanded") \
1890 range(0.1, 1000.0) \
1891 \
1892 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1893 "Entries per bucket below which the table should be shrunk") \
1894 range(0.01, 100.0) \
1895 \
1896 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1897 "Desired entries per bucket when resizing the table") \
1898 range(0.01, 1000.0) \
1899 \
1900 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1901 "Minimum number of dead table entries for cleaning the table") \
1902 \
1903 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1904 "Minimum percentage of dead table entries for cleaning the table") \
1905 range(1, 100) \
1906 \
1907 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1908 "Force more frequent table resizing") \
1909 \
1910 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1911 "Seed for the table hashing function; 0 requests computed seed") \
1912 \
1913 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1914 "Enable internal testing APIs") \
1915 \
1916 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1917 "Accesses to all variables should always be atomic") \
1918 \
1919 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1920 "Use unaligned memory accesses in Unsafe") \
1921 \
1922 product_pd(bool, PreserveFramePointer, \
1923 "Use the FP register for holding the frame pointer " \
1924 "and not as a general purpose register.") \
1925 \
1926 product(size_t, AsyncLogBufferSize, 2*M, \
1927 "Memory budget (in bytes) for the buffer of Asynchronous " \
1928 "Logging (-Xlog:async).") \
1929 range(100*K, 50*M) \
1930 \
1931 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1932 "When a class C is loaded, check that " \
1933 "(1) all intrinsics defined by the VM for class C are present "\
1934 "in the loaded class file and are marked with the " \
1935 "@IntrinsicCandidate annotation, that " \
1936 "(2) there is an intrinsic registered for all loaded methods " \
1937 "that are annotated with the @IntrinsicCandidate annotation, " \
1938 "and that " \
1939 "(3) no orphan methods exist for class C (i.e., methods for " \
1940 "which the VM declares an intrinsic but that are not declared "\
1941 "in the loaded class C. " \
1942 "Check (3) is available only in debug builds.") \
1943 \
1944 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1945 "Threshold small size (in bytes) for clearing arrays. " \
1946 "Anything this size or smaller may get converted to discrete " \
1947 "scalar stores.") \
1948 range(0, max_intx) \
1949 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1950 \
1951 product(ccstr, AllocateHeapAt, nullptr, \
1952 "Path to the directory where a temporary file will be created " \
1953 "to use as the backing store for Java Heap.") \
1954 \
1955 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1956 "Enable VM continuations support") \
1957 \
1958 develop(bool, LoomDeoptAfterThaw, false, \
1959 "Deopt stack after thaw") \
1960 \
1961 develop(bool, LoomVerifyAfterThaw, false, \
1962 "Verify stack after thaw") \
1963 \
1964 develop(bool, VerifyContinuations, false, \
1965 "Verify continuation consistency") \
1966 \
1967 develop(bool, UseContinuationFastPath, true, \
1968 "Use fast-path frame walking in continuations") \
1969 \
1970 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1971 "Run periodic metaspace verifications (0 - none, " \
1972 "1 - always, >1 every nth interval)") \
1973 \
1974 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1975 "On internal errors, include registers in error report.") \
1976 \
1977 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1978 "leverage profiling for table/lookup switch") \
1979 \
1980 develop(bool, TraceMemoryWriteback, false, \
1981 "Trace memory writeback operations") \
1982 \
1983 JFR_ONLY(product(bool, FlightRecorder, false, \
1984 "(Deprecated) Enable Flight Recorder")) \
1985 \
1986 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1987 "Flight Recorder options")) \
1988 \
1989 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1990 "Start flight recording with options")) \
1991 \
1992 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1993 "Use platform unstable time where supported for timestamps only") \
1994 \
1995 product(bool, EnableValhalla, true, \
1996 "Enable experimental Valhalla features") \
1997 \
1998 product_pd(bool, InlineTypePassFieldsAsArgs, \
1999 "Pass each inline type field as an argument at calls") \
2000 \
2001 product_pd(bool, InlineTypeReturnedAsFields, \
2002 "Return fields instead of an inline type reference") \
2003 \
2004 develop(bool, StressCallingConvention, false, \
2005 "Stress the scalarized calling convention.") \
2006 \
2007 product(bool, UseArrayMarkWordCheck, NOT_LP64(false) LP64_ONLY(true), \
2008 "Use bits in the mark word to check for flat/null-free arrays") \
2009 \
2010 product(ccstrlist, ForceNonTearable, "", DIAGNOSTIC, \
2011 "List of inline classes which are forced to be atomic " \
2012 "(whitespace and commas separate names, " \
2013 "and leading and trailing stars '*' are wildcards)") \
2014 \
2015 product(bool, UseEmptySlotsInSupers, true, \
2016 "Allow allocating fields in empty slots of super-classes") \
2017 \
2018 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
2019 "Make nmethod barriers deoptimise a lot.") \
2020 \
2021 develop(bool, VerifyCrossModifyFence, \
2022 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
2023 "Mark all threads after a safepoint, and clear on a modify " \
2024 "fence. Add cleanliness checks.") \
2025 \
2026 product(int, LockingMode, LM_LEGACY, \
2027 "Select locking mode: " \
2028 "0: monitors only (LM_MONITOR), " \
2029 "1: monitors & legacy stack-locking (LM_LEGACY, default), " \
2030 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT)") \
2031 range(0, 2) \
2032 \
2033 product(uint, TrimNativeHeapInterval, 0, EXPERIMENTAL, \
2034 "Interval, in ms, at which the JVM will trim the native heap if " \
2035 "the platform supports that. Lower values will reclaim memory " \
2036 "more eagerly at the cost of higher overhead. A value of 0 " \
2037 "(default) disables native heap trimming.") \
2038 range(0, UINT_MAX) \
2039 \
2040 develop(bool, SimulateFullAddressSpace, false, \
2041 "Simulates a very populated, fragmented address space; no " \
2042 "targeted reservations will succeed.") \
2043 \
2044 product(bool, ProfileExceptionHandlers, true, \
2045 "Profile exception handlers") \
2046
2047 // end of RUNTIME_FLAGS
2048
2049 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2050 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2051 DECLARE_FLAGS(RUNTIME_FLAGS)
2052 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2053
2054 #endif // SHARE_RUNTIME_GLOBALS_HPP