1 /*
2 * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_RUNTIME_GLOBALS_HPP
26 #define SHARE_RUNTIME_GLOBALS_HPP
27
28 #include "compiler/compiler_globals_pd.hpp"
29 #include "runtime/globals_shared.hpp"
30 #include "utilities/align.hpp"
31 #include "utilities/globalDefinitions.hpp"
32 #include "utilities/macros.hpp"
33 #include CPU_HEADER(globals)
34 #include OS_HEADER(globals)
35 #include OS_CPU_HEADER(globals)
36
37 // develop flags are settable / visible only during development and are constant in the PRODUCT version
38 // product flags are always settable / visible
39 // 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 are not
71 // part of the officially supported product, but are 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 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
79 // UnlockExperimentalVMOptions flag, which allows the control and
80 // modification of the experimental flags.
81 //
82 // Nota bene: neither diagnostic nor experimental options should be used casually,
83 // and they are not supported on production loads, except under explicit
84 // direction from support engineers.
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 notproduct, \
121 range, \
122 constraint) \
123 \
124 product(bool, UseCompressedOops, false, \
125 "Use 32-bit object references in 64-bit VM. " \
126 "lp64_product means flag is always constant in 32 bit VM") \
127 \
128 product(bool, UseCompressedClassPointers, false, \
129 "Use 32-bit class pointers in 64-bit VM. " \
130 "lp64_product means flag is always constant in 32 bit VM") \
131 \
132 product(int, ObjectAlignmentInBytes, 8, \
133 "Default object alignment in bytes, 8 is minimum") \
134 range(8, 256) \
135 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
136
137 #else
138 // !_LP64
139
140 #define LP64_RUNTIME_FLAGS(develop, \
141 develop_pd, \
142 product, \
143 product_pd, \
144 notproduct, \
145 range, \
146 constraint)
147 const bool UseCompressedOops = false;
148 const bool UseCompressedClassPointers = false;
149 const int ObjectAlignmentInBytes = 8;
150
151 #endif // _LP64
152
153 #define RUNTIME_FLAGS(develop, \
154 develop_pd, \
155 product, \
156 product_pd, \
157 notproduct, \
158 range, \
159 constraint) \
160 \
161 notproduct(bool, CheckCompressedOops, true, \
162 "Generate checks in encoding/decoding code in debug VM") \
163 \
164 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
165 "Heap allocation steps through preferred address regions to find" \
166 " where it can allocate the heap. Number of steps to take per " \
167 "region.") \
168 range(1, max_uintx) \
169 \
170 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
171 "If nonzero set a timeout in milliseconds for handshakes") \
172 \
173 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
174 "Force safe construction, as if all fields are final.") \
175 \
176 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
177 "Enable normal processing of flags relating to field diagnostics")\
178 \
179 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
180 "Enable normal processing of flags relating to experimental " \
181 "features") \
182 \
183 product(bool, JavaMonitorsInStackTrace, true, \
184 "Print information about Java monitor locks when the stacks are " \
185 "dumped") \
186 \
187 product_pd(bool, UseLargePages, \
188 "Use large page memory") \
189 \
190 product_pd(bool, UseLargePagesIndividualAllocation, \
191 "Allocate large pages individually for better affinity") \
192 \
193 develop(bool, LargePagesIndividualAllocationInjectError, false, \
194 "Fail large pages individual allocation") \
195 \
196 product(bool, UseNUMA, false, \
197 "Use NUMA if available") \
198 \
199 product(bool, UseNUMAInterleaving, false, \
200 "Interleave memory across NUMA nodes if available") \
201 \
202 product(size_t, NUMAInterleaveGranularity, 2*M, \
203 "Granularity to use for NUMA interleaving on Windows OS") \
204 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
205 \
206 product(uintx, NUMAChunkResizeWeight, 20, \
207 "Percentage (0-100) used to weight the current sample when " \
208 "computing exponentially decaying average for " \
209 "AdaptiveNUMAChunkSizing") \
210 range(0, 100) \
211 \
212 product(size_t, NUMASpaceResizeRate, 1*G, \
213 "Do not reallocate more than this amount per collection") \
214 range(0, max_uintx) \
215 \
216 product(bool, UseAdaptiveNUMAChunkSizing, true, \
217 "Enable adaptive chunk sizing for NUMA") \
218 \
219 product(bool, NUMAStats, false, \
220 "Print NUMA stats in detailed heap information") \
221 \
222 product(uintx, NUMAPageScanRate, 256, \
223 "Maximum number of pages to include in the page scan procedure") \
224 range(0, max_uintx) \
225 \
226 product(bool, UseAES, false, \
227 "Control whether AES instructions are used when available") \
228 \
229 product(bool, UseFMA, false, \
230 "Control whether FMA instructions are used when available") \
231 \
232 product(bool, UseSHA, false, \
233 "Control whether SHA instructions are used when available") \
234 \
235 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
236 "Use intrinsics for GHASH versions of crypto") \
237 \
238 product(bool, UseBASE64Intrinsics, false, \
239 "Use intrinsics for java.util.Base64") \
240 \
241 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
242 "Use intrinsics for sun.security.util.math.intpoly") \
243 \
244 product(size_t, LargePageSizeInBytes, 0, \
245 "Maximum large page size used (0 will use the default large " \
246 "page size for the environment as the maximum)") \
247 range(0, max_uintx) \
248 \
249 product(size_t, LargePageHeapSizeThreshold, 128*M, \
250 "Use large pages if maximum heap is at least this big") \
251 range(0, max_uintx) \
252 \
253 product(bool, ForceTimeHighResolution, false, \
254 "Using high time resolution (for Win32 only)") \
255 \
256 develop(bool, TracePcPatching, false, \
257 "Trace usage of frame::patch_pc") \
258 \
259 develop(bool, TraceRelocator, false, \
260 "Trace the bytecode relocator") \
261 \
262 \
263 product(bool, SafepointALot, false, DIAGNOSTIC, \
264 "Generate a lot of safepoints. This works with " \
265 "GuaranteedSafepointInterval") \
266 \
267 product(bool, HandshakeALot, false, DIAGNOSTIC, \
268 "Generate a lot of handshakes. This works with " \
269 "GuaranteedSafepointInterval") \
270 \
271 product_pd(bool, BackgroundCompilation, \
272 "A thread requesting compilation is not blocked during " \
273 "compilation") \
274 \
275 product(bool, MethodFlushing, true, \
276 "Reclamation of compiled methods") \
277 \
278 develop(bool, VerifyStack, false, \
279 "Verify stack of each thread when it is entering a runtime call") \
280 \
281 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
282 "Make all non code cache addresses to be unreachable by " \
283 "forcing use of 64bit literal fixups") \
284 \
285 develop(bool, TraceDerivedPointers, false, \
286 "Trace traversal of derived pointers on stack") \
287 \
288 notproduct(bool, TraceCodeBlobStacks, false, \
289 "Trace stack-walk of codeblobs") \
290 \
291 notproduct(bool, PrintRewrites, false, \
292 "Print methods that are being rewritten") \
293 \
294 product(bool, UseInlineCaches, true, \
295 "Use Inline Caches for virtual calls ") \
296 \
297 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
298 "Inline arraycopy native that is known to be part of " \
299 "base library DLL") \
300 \
301 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
302 "Inline Object::hashCode() native that is known to be part " \
303 "of base library DLL") \
304 \
305 product(bool, InlineNatives, true, DIAGNOSTIC, \
306 "Inline natives that are known to be part of base library DLL") \
307 \
308 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
309 "Inline SinD, CosD, etc.") \
310 \
311 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
312 "Inline Class.isInstance, etc") \
313 \
314 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
315 "Inline Thread.currentThread, etc") \
316 \
317 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
318 "Inline memory ops (native methods) from Unsafe") \
319 \
320 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
321 "Use intrinsics for AES versions of crypto") \
322 \
323 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
324 "Use intrinsics for the paralleled version of AES/CTR crypto") \
325 \
326 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
327 "Use intrinsics for the vectorized version of ChaCha20") \
328 \
329 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
330 "Use intrinsics for MD5 crypto hash function") \
331 \
332 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
333 "Use intrinsics for SHA-1 crypto hash function. " \
334 "Requires that UseSHA is enabled.") \
335 \
336 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
337 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
338 "Requires that UseSHA is enabled.") \
339 \
340 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
341 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
342 "Requires that UseSHA is enabled.") \
343 \
344 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
345 "Use intrinsics for SHA3 crypto hash function. " \
346 "Requires that UseSHA is enabled.") \
347 \
348 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
349 "use intrinsics for java.util.zip.CRC32") \
350 \
351 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
352 "use intrinsics for java.util.zip.CRC32C") \
353 \
354 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
355 "use intrinsics for java.util.zip.Adler32") \
356 \
357 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
358 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
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(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
367 "do not expand intrinsics whose (internal) names appear here") \
368 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
369 \
370 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
371 "Control intrinsics using a list of +/- (internal) names, " \
372 "separated by commas") \
373 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
374 \
375 develop(bool, TraceCallFixup, false, \
376 "Trace all call fixups") \
377 \
378 develop(bool, DeoptimizeALot, false, \
379 "Deoptimize at every exit from the runtime system") \
380 \
381 notproduct(ccstrlist, DeoptimizeOnlyAt, "", \
382 "A comma separated list of bcis to deoptimize at") \
383 \
384 develop(bool, DeoptimizeRandom, false, \
385 "Deoptimize random frames on random exit from the runtime system")\
386 \
387 notproduct(bool, ZombieALot, false, \
388 "Create non-entrant nmethods at exit from the runtime system") \
389 \
390 notproduct(bool, WalkStackALot, false, \
391 "Trace stack (no print) at every exit from the runtime system") \
392 \
393 develop(bool, DeoptimizeObjectsALot, false, \
394 "For testing purposes concurrent threads revert optimizations " \
395 "based on escape analysis at intervals given with " \
396 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
397 "with DeoptimizeObjectsALotThreadCountSingle and " \
398 "DeoptimizeObjectsALotThreadCountAll.") \
399 \
400 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
401 "Interval for DeoptimizeObjectsALot.") \
402 range(0, max_jlong) \
403 \
404 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
405 "The number of threads that revert optimizations based on " \
406 "escape analysis for a single thread if DeoptimizeObjectsALot " \
407 "is enabled. The target thread is selected round robin." ) \
408 range(0, max_jint) \
409 \
410 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
411 "The number of threads that revert optimizations based on " \
412 "escape analysis for all threads if DeoptimizeObjectsALot " \
413 "is enabled." ) \
414 range(0, max_jint) \
415 \
416 notproduct(bool, VerifyLastFrame, false, \
417 "Verify oops on last frame on entry to VM") \
418 \
419 product(bool, SafepointTimeout, false, \
420 "Time out and warn or fail after SafepointTimeoutDelay " \
421 "milliseconds if failed to reach safepoint") \
422 \
423 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
424 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
425 \
426 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
427 "Abort upon failure to complete VM operation promptly") \
428 \
429 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
430 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
431 range(0, max_intx) \
432 \
433 product(bool, MaxFDLimit, true, \
434 "Bump the number of file descriptors to maximum (Unix only)") \
435 \
436 product(bool, LogEvents, true, DIAGNOSTIC, \
437 "Enable the various ring buffer event logs") \
438 \
439 product(uintx, LogEventsBufferEntries, 20, DIAGNOSTIC, \
440 "Number of ring buffer event logs") \
441 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
442 \
443 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
444 "Enable the Java bytecode verifier for remote classes") \
445 \
446 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
447 "Enable the Java bytecode verifier for local classes") \
448 \
449 develop(bool, VerifyStackAtCalls, false, \
450 "Verify that the stack pointer is unchanged after calls") \
451 \
452 develop(bool, TraceJavaAssertions, false, \
453 "Trace java language assertions") \
454 \
455 notproduct(bool, VerifyCodeCache, false, \
456 "Verify code cache on memory allocation/deallocation") \
457 \
458 develop(bool, ZapResourceArea, trueInDebug, \
459 "Zap freed resource/arena space") \
460 \
461 notproduct(bool, ZapVMHandleArea, trueInDebug, \
462 "Zap freed VM handle space") \
463 \
464 notproduct(bool, ZapStackSegments, trueInDebug, \
465 "Zap allocated/freed stack segments") \
466 \
467 develop(bool, ZapUnusedHeapArea, trueInDebug, \
468 "Zap unused heap space") \
469 \
470 develop(bool, CheckZapUnusedHeapArea, false, \
471 "Check zapping of unused heap space") \
472 \
473 develop(bool, ZapFillerObjects, trueInDebug, \
474 "Zap filler objects") \
475 \
476 product(bool, ExecutingUnitTests, false, \
477 "Whether the JVM is running unit tests or not") \
478 \
479 develop(uint, ErrorHandlerTest, 0, \
480 "If > 0, provokes an error after VM initialization; the value " \
481 "determines which error to provoke. See controlled_crash() " \
482 "in vmError.cpp.") \
483 range(0, 17) \
484 \
485 develop(uint, TestCrashInErrorHandler, 0, \
486 "If > 0, provokes an error inside VM error handler (a secondary " \
487 "crash). see controlled_crash() in vmError.cpp") \
488 range(0, 17) \
489 \
490 develop(bool, TestSafeFetchInErrorHandler, false , \
491 "If true, tests SafeFetch inside error handler.") \
492 \
493 develop(bool, TestUnresponsiveErrorHandler, false, \
494 "If true, simulates an unresponsive error handler.") \
495 \
496 develop(bool, Verbose, false, \
497 "Print additional debugging information from other modes") \
498 \
499 develop(bool, PrintMiscellaneous, false, \
500 "Print uncategorized debugging information (requires +Verbose)") \
501 \
502 develop(bool, WizardMode, false, \
503 "Print much more debugging information") \
504 \
505 product(bool, ShowMessageBoxOnError, false, \
506 "Keep process alive on VM fatal error") \
507 \
508 product(bool, CreateCoredumpOnCrash, true, \
509 "Create core/mini dump on VM fatal error") \
510 \
511 product(uint64_t, ErrorLogTimeout, 2 * 60, \
512 "Timeout, in seconds, to limit the time spent on writing an " \
513 "error log in case of a crash.") \
514 range(0, (uint64_t)max_jlong/1000) \
515 \
516 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
517 "If enabled, show details on secondary crashes in the error log") \
518 \
519 develop(intx, TraceDwarfLevel, 0, \
520 "Debug levels for the dwarf parser") \
521 range(0, 4) \
522 \
523 product(bool, SuppressFatalErrorMessage, false, \
524 "Report NO fatal error message (avoid deadlock)") \
525 \
526 product(ccstrlist, OnError, "", \
527 "Run user-defined commands on fatal error; see VMError.cpp " \
528 "for examples") \
529 \
530 product(ccstrlist, OnOutOfMemoryError, "", \
531 "Run user-defined commands on first java.lang.OutOfMemoryError " \
532 "thrown from JVM") \
533 \
534 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
535 "Dump heap to file before any major stop-the-world GC") \
536 \
537 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
538 "Dump heap to file after any major stop-the-world GC") \
539 \
540 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
541 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
542 "from JVM") \
543 \
544 product(ccstr, HeapDumpPath, NULL, MANAGEABLE, \
545 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \
546 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
547 "in the working directory)") \
548 \
549 product(intx, HeapDumpGzipLevel, 0, MANAGEABLE, \
550 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \
551 "level of the dump file. 0 (the default) disables gzip " \
552 "compression. Otherwise the level must be between 1 and 9.") \
553 range(0, 9) \
554 \
555 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
556 "Native memory tracking options") \
557 \
558 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
559 "Print native memory tracking summary data if it is on") \
560 \
561 product(bool, LogCompilation, false, DIAGNOSTIC, \
562 "Log compilation activity in detail to LogFile") \
563 \
564 product(bool, PrintCompilation, false, \
565 "Print compilations") \
566 \
567 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
568 "Repeat compilation without installing code (number of times)") \
569 range(0, max_jint) \
570 \
571 product(bool, PrintExtendedThreadInfo, false, \
572 "Print more information in thread dump") \
573 \
574 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
575 "0: do not allow scavengable oops in the code cache; " \
576 "1: allow scavenging from the code cache; " \
577 "2: emit as many constants as the compiler can see") \
578 range(0, 2) \
579 \
580 product(bool, AlwaysRestoreFPU, false, \
581 "Restore the FPU control word after every JNI call (expensive)") \
582 \
583 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
584 "Print additional statistics per compilation") \
585 \
586 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
587 "Print code generated for i2c/c2i adapters") \
588 \
589 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
590 "Verify that i2c/c2i adapters are called properly") \
591 \
592 develop(bool, VerifyAdapterSharing, false, \
593 "Verify that the code for shared adapters is the equivalent") \
594 \
595 product(bool, PrintAssembly, false, DIAGNOSTIC, \
596 "Print assembly code (using external disassembler.so)") \
597 \
598 product(ccstr, PrintAssemblyOptions, NULL, DIAGNOSTIC, \
599 "Print options string passed to disassembler.so") \
600 \
601 notproduct(bool, PrintNMethodStatistics, false, \
602 "Print a summary statistic for the generated nmethods") \
603 \
604 product(bool, PrintNMethods, false, DIAGNOSTIC, \
605 "Print assembly code for nmethods when generated") \
606 \
607 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
608 "Print assembly code for native nmethods when generated") \
609 \
610 develop(bool, PrintDebugInfo, false, \
611 "Print debug information for all nmethods when generated") \
612 \
613 develop(bool, PrintRelocations, false, \
614 "Print relocation information for all nmethods when generated") \
615 \
616 develop(bool, PrintDependencies, false, \
617 "Print dependency information for all nmethods when generated") \
618 \
619 develop(bool, PrintExceptionHandlers, false, \
620 "Print exception handler tables for all nmethods when generated") \
621 \
622 develop(bool, StressCompiledExceptionHandlers, false, \
623 "Exercise compiled exception handlers") \
624 \
625 develop(bool, InterceptOSException, false, \
626 "Start debugger when an implicit OS (e.g. NULL) " \
627 "exception happens") \
628 \
629 product(bool, PrintCodeCache, false, \
630 "Print the code cache memory usage when exiting") \
631 \
632 develop(bool, PrintCodeCache2, false, \
633 "Print detailed usage information on the code cache when exiting")\
634 \
635 product(bool, PrintCodeCacheOnCompilation, false, \
636 "Print the code cache memory usage each time a method is " \
637 "compiled") \
638 \
639 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
640 "Print code heap usage statistics on exit and on full condition") \
641 \
642 product(bool, PrintStubCode, false, DIAGNOSTIC, \
643 "Print generated stub code") \
644 \
645 product(bool, StackTraceInThrowable, true, \
646 "Collect backtrace in throwable when exception happens") \
647 \
648 product(bool, OmitStackTraceInFastThrow, true, \
649 "Omit backtraces for some 'hot' exceptions in optimized code") \
650 \
651 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
652 "Show exception messages from RuntimeExceptions that contain " \
653 "snippets of the failing code. Disable this to improve privacy.") \
654 \
655 product(bool, PrintWarnings, true, \
656 "Print JVM warnings to output stream") \
657 \
658 product(bool, RegisterFinalizersAtInit, true, \
659 "Register finalizable objects at end of Object.<init> or " \
660 "after allocation") \
661 \
662 develop(bool, RegisterReferences, true, \
663 "Tell whether the VM should register soft/weak/final/phantom " \
664 "references") \
665 \
666 develop(bool, PrintCodeCacheExtension, false, \
667 "Print extension of code cache") \
668 \
669 develop(bool, UsePrivilegedStack, true, \
670 "Enable the security JVM functions") \
671 \
672 product(bool, ClassUnloading, true, \
673 "Do unloading of classes") \
674 \
675 product(bool, ClassUnloadingWithConcurrentMark, true, \
676 "Do unloading of classes with a concurrent marking cycle") \
677 \
678 notproduct(bool, PrintSystemDictionaryAtExit, false, \
679 "Print the system dictionary at exit") \
680 \
681 notproduct(bool, PrintClassLoaderDataGraphAtExit, false, \
682 "Print the class loader data graph at exit") \
683 \
684 product(bool, AllowParallelDefineClass, false, \
685 "Allow parallel defineClass requests for class loaders " \
686 "registering as parallel capable") \
687 \
688 product(bool, EnableWaitForParallelLoad, false, \
689 "(Deprecated) Enable legacy parallel classloading logic for " \
690 "class loaders not registered as parallel capable") \
691 \
692 product_pd(bool, DontYieldALot, \
693 "Throw away obvious excess yield calls") \
694 \
695 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
696 "Disable the use of stack guard pages if the JVM is loaded " \
697 "on the primordial process thread") \
698 \
699 product(bool, PostVirtualThreadCompatibleLifecycleEvents, true, EXPERIMENTAL, \
700 "Post virtual thread ThreadStart and ThreadEnd events for " \
701 "virtual thread unaware agents") \
702 \
703 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
704 "Do JVMTI virtual thread mount/unmount transitions " \
705 "(disabling this flag implies no JVMTI events are posted)") \
706 \
707 /* notice: the max range value here is max_jint, not max_intx */ \
708 /* because of overflow issue */ \
709 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
710 "Async deflate idle monitors every so many milliseconds when " \
711 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
712 range(0, max_jint) \
713 \
714 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
715 "Used to estimate a variable ceiling based on number of threads " \
716 "for use with MonitorUsedDeflationThreshold (0 is off).") \
717 range(0, max_uintx) \
718 \
719 /* notice: the max range value here is max_jint, not max_intx */ \
720 /* because of overflow issue */ \
721 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
722 "The maximum number of monitors to deflate, unlink and delete " \
723 "at one time (minimum is 1024).") \
724 range(1024, max_jint) \
725 \
726 product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
727 "Percentage of used monitors before triggering deflation (0 is " \
728 "off). The check is performed on GuaranteedSafepointInterval " \
729 "or AsyncDeflationInterval.") \
730 range(0, 100) \
731 \
732 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
733 "Max number of no progress async deflation attempts to tolerate " \
734 "before adjusting the in_use_list_ceiling up (0 is off).") \
735 range(0, max_uintx) \
736 \
737 product(intx, hashCode, 5, EXPERIMENTAL, \
738 "(Unstable) select hashCode generation algorithm") \
739 \
740 product(bool, ReduceSignalUsage, false, \
741 "Reduce the use of OS signals in Java and/or the VM") \
742 \
743 develop(bool, LoadLineNumberTables, true, \
744 "Tell whether the class file parser loads line number tables") \
745 \
746 develop(bool, LoadLocalVariableTables, true, \
747 "Tell whether the class file parser loads local variable tables") \
748 \
749 develop(bool, LoadLocalVariableTypeTables, true, \
750 "Tell whether the class file parser loads local variable type" \
751 "tables") \
752 \
753 product(bool, AllowUserSignalHandlers, false, \
754 "Application will install primary signal handlers for the JVM " \
755 "(Unix only)") \
756 \
757 product(bool, UseSignalChaining, true, \
758 "Use signal-chaining to invoke signal handlers installed " \
759 "by the application (Unix only)") \
760 \
761 product(bool, RestoreMXCSROnJNICalls, false, \
762 "Restore MXCSR when returning from JNI calls") \
763 \
764 product(bool, CheckJNICalls, false, \
765 "Verify all arguments to JNI calls") \
766 \
767 product(bool, UseFastJNIAccessors, true, \
768 "Use optimized versions of Get<Primitive>Field") \
769 \
770 product(intx, MaxJNILocalCapacity, 65536, \
771 "Maximum allowable local JNI handle capacity to " \
772 "EnsureLocalCapacity() and PushLocalFrame(), " \
773 "where <= 0 is unlimited, default: 65536") \
774 range(min_intx, max_intx) \
775 \
776 product(bool, EagerXrunInit, false, \
777 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
778 "but not all -Xrun libraries may support the state of the VM " \
779 "at this time") \
780 \
781 product(bool, PreserveAllAnnotations, false, \
782 "Preserve RuntimeInvisibleAnnotations as well " \
783 "as RuntimeVisibleAnnotations") \
784 \
785 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
786 "Number of OutOfMemoryErrors preallocated with backtrace") \
787 \
788 product(bool, UseXMMForArrayCopy, false, \
789 "Use SSE2 MOVQ instruction for Arraycopy") \
790 \
791 notproduct(bool, PrintFieldLayout, false, \
792 "Print field layout for each class") \
793 \
794 notproduct(bool, PrintInlineLayout, false, \
795 "Print field layout for each inline type") \
796 \
797 notproduct(bool, PrintFlatArrayLayout, false, \
798 "Print array layout for each inline type array") \
799 \
800 product(intx, FlatArrayElementMaxSize, -1, \
801 "Max size for flattening inline array elements, <0 no limit") \
802 \
803 product(intx, InlineFieldMaxFlatSize, 128, \
804 "Max size for flattening inline type fields, <0 no limit") \
805 \
806 product(intx, FlatArrayElementMaxOops, 4, \
807 "Max nof embedded object references in an inline type to flatten, <0 no limit") \
808 \
809 product(bool, InlineArrayAtomicAccess, false, \
810 "Atomic inline array accesses by-default, for all inline arrays") \
811 \
812 /* Need to limit the extent of the padding to reasonable size. */\
813 /* 8K is well beyond the reasonable HW cache line size, even with */\
814 /* aggressive prefetching, while still leaving the room for segregating */\
815 /* among the distinct pages. */\
816 product(intx, ContendedPaddingWidth, 128, \
817 "How many bytes to pad the fields/classes marked @Contended with")\
818 range(0, 8192) \
819 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
820 \
821 product(bool, EnableContended, true, \
822 "Enable @Contended annotation support") \
823 \
824 product(bool, RestrictContended, true, \
825 "Restrict @Contended to trusted classes") \
826 \
827 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
828 "Detect and take action upon identifying synchronization on " \
829 "value based classes. Modes: " \
830 "0: off; " \
831 "1: exit with fatal error; " \
832 "2: log message to stdout. Output file can be specified with " \
833 " -Xlog:valuebasedclasses. If JFR is running it will " \
834 " also generate JFR events.") \
835 range(0, 2) \
836 \
837 product(bool, ExitOnOutOfMemoryError, false, \
838 "JVM exits on the first occurrence of an out-of-memory error " \
839 "thrown from JVM") \
840 \
841 product(bool, CrashOnOutOfMemoryError, false, \
842 "JVM aborts, producing an error log and core/mini dump, on the " \
843 "first occurrence of an out-of-memory error thrown from JVM") \
844 \
845 /* tracing */ \
846 \
847 develop(bool, StressRewriter, false, \
848 "Stress linktime bytecode rewriting") \
849 \
850 product(ccstr, TraceJVMTI, NULL, \
851 "Trace flags for JVMTI functions and events") \
852 \
853 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
854 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
855 "This option can change an EMCP method into an obsolete method " \
856 "and can affect tests that expect specific methods to be EMCP. " \
857 "This option should be used with caution.") \
858 \
859 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
860 "(Deprecated) Allow redefinition to add and delete private " \
861 "static or final methods for compatibility with old releases") \
862 \
863 develop(bool, TraceBytecodes, false, \
864 "Trace bytecode execution") \
865 \
866 develop(bool, TraceICs, false, \
867 "Trace inline cache changes") \
868 \
869 notproduct(bool, TraceInvocationCounterOverflow, false, \
870 "Trace method invocation counter overflow") \
871 \
872 develop(bool, TraceInlineCacheClearing, false, \
873 "Trace clearing of inline caches in nmethods") \
874 \
875 develop(bool, TraceDependencies, false, \
876 "Trace dependencies") \
877 \
878 develop(bool, VerifyDependencies, trueInDebug, \
879 "Exercise and verify the compilation dependency mechanism") \
880 \
881 develop(bool, TraceNewOopMapGeneration, false, \
882 "Trace OopMapGeneration") \
883 \
884 develop(bool, TraceNewOopMapGenerationDetailed, false, \
885 "Trace OopMapGeneration: print detailed cell states") \
886 \
887 develop(bool, TimeOopMap, false, \
888 "Time calls to GenerateOopMap::compute_map() in sum") \
889 \
890 develop(bool, TimeOopMap2, false, \
891 "Time calls to GenerateOopMap::compute_map() individually") \
892 \
893 develop(bool, TraceOopMapRewrites, false, \
894 "Trace rewriting of methods during oop map generation") \
895 \
896 develop(bool, TraceICBuffer, false, \
897 "Trace usage of IC buffer") \
898 \
899 develop(bool, TraceCompiledIC, false, \
900 "Trace changes of compiled IC") \
901 \
902 develop(bool, FLSVerifyDictionary, false, \
903 "Do lots of (expensive) FLS dictionary verification") \
904 \
905 \
906 notproduct(bool, CheckMemoryInitialization, false, \
907 "Check memory initialization") \
908 \
909 product(uintx, ProcessDistributionStride, 4, \
910 "Stride through processors when distributing processes") \
911 range(0, max_juint) \
912 \
913 develop(bool, TraceFinalizerRegistration, false, \
914 "Trace registration of final references") \
915 \
916 product(bool, IgnoreEmptyClassPaths, false, \
917 "Ignore empty path elements in -classpath") \
918 \
919 product(bool, PrintHeapAtSIGBREAK, true, \
920 "Print heap layout in response to SIGBREAK") \
921 \
922 product(bool, PrintClassHistogram, false, MANAGEABLE, \
923 "Print a histogram of class instances") \
924 \
925 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
926 "The percentage of the used heap that the instances of a class " \
927 "must occupy for the class to generate a trace event") \
928 range(0.0, 100.0) \
929 \
930 /* JVMTI heap profiling */ \
931 \
932 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
933 "Verify memory system before JVMTI iteration") \
934 \
935 /* compiler */ \
936 \
937 /* notice: the max range value here is max_jint, not max_intx */ \
938 /* because of overflow issue */ \
939 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
940 "Number of compiler threads to run") \
941 range(0, max_jint) \
942 constraint(CICompilerCountConstraintFunc, AfterErgo) \
943 \
944 product(bool, UseDynamicNumberOfCompilerThreads, true, \
945 "Dynamically choose the number of parallel compiler threads") \
946 \
947 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
948 "Reduce the number of parallel compiler threads when they " \
949 "are not used") \
950 \
951 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
952 "Trace creation and removal of compiler threads") \
953 \
954 develop(bool, InjectCompilerCreationFailure, false, \
955 "Inject thread creation failures for " \
956 "UseDynamicNumberOfCompilerThreads") \
957 \
958 develop(bool, GenerateSynchronizationCode, true, \
959 "generate locking/unlocking code for synchronized methods and " \
960 "monitors") \
961 \
962 develop(bool, GenerateRangeChecks, true, \
963 "Generate range checks for array accesses") \
964 \
965 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
966 "Generate code for implicit null checks") \
967 \
968 product_pd(bool, TrapBasedNullChecks, \
969 "Generate code for null checks that uses a cmp and trap " \
970 "instruction raising SIGTRAP. This is only used if an access to" \
971 "null (+offset) will not raise a SIGSEGV, i.e.," \
972 "ImplicitNullChecks don't work (PPC64).") \
973 \
974 product(bool, EnableThreadSMRExtraValidityChecks, true, DIAGNOSTIC, \
975 "Enable Thread SMR extra validity checks") \
976 \
977 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
978 "Enable Thread SMR Statistics") \
979 \
980 product(bool, UseNotificationThread, true, \
981 "Use Notification Thread") \
982 \
983 product(bool, Inline, true, \
984 "Enable inlining") \
985 \
986 product(bool, ClipInlining, true, \
987 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
988 \
989 develop(bool, UseCHA, true, \
990 "Enable CHA") \
991 \
992 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \
993 "Use vtable information during CHA") \
994 \
995 product(bool, UseTypeProfile, true, \
996 "Check interpreter profile for historically monomorphic calls") \
997 \
998 product(bool, PrintInlining, false, DIAGNOSTIC, \
999 "Print inlining optimizations") \
1000 \
1001 product(bool, UsePopCountInstruction, false, \
1002 "Use population count instruction") \
1003 \
1004 develop(bool, TraceMethodReplacement, false, \
1005 "Print when methods are replaced do to recompilation") \
1006 \
1007 product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC, \
1008 "print statistics about method flushing") \
1009 \
1010 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
1011 "Minimum number of sweeper passes before an nmethod " \
1012 "can be flushed") \
1013 range(0, max_intx) \
1014 \
1015 develop(bool, StressCodeBuffers, false, \
1016 "Exercise code buffer expansion and other rare state changes") \
1017 \
1018 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
1019 "Generate extra debugging information for non-safepoints in " \
1020 "nmethods") \
1021 \
1022 product(bool, PrintVMOptions, false, \
1023 "Print flags that appeared on the command line") \
1024 \
1025 product(bool, IgnoreUnrecognizedVMOptions, false, \
1026 "Ignore unrecognized VM options") \
1027 \
1028 product(bool, PrintCommandLineFlags, false, \
1029 "Print flags specified on command line or set by ergonomics") \
1030 \
1031 product(bool, PrintFlagsInitial, false, \
1032 "Print all VM flags before argument processing and exit VM") \
1033 \
1034 product(bool, PrintFlagsFinal, false, \
1035 "Print all VM flags after argument and ergonomic processing") \
1036 \
1037 notproduct(bool, PrintFlagsWithComments, false, \
1038 "Print all VM flags with default values and descriptions and " \
1039 "exit") \
1040 \
1041 product(bool, PrintFlagsRanges, false, \
1042 "Print VM flags and their ranges") \
1043 \
1044 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1045 "Use a mutex to serialize output to tty and LogFile") \
1046 \
1047 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1048 "Display all VM output on the tty, independently of LogVMOutput") \
1049 \
1050 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1051 "Save VM output to LogFile") \
1052 \
1053 product(ccstr, LogFile, NULL, DIAGNOSTIC, \
1054 "If LogVMOutput or LogCompilation is on, save VM output to " \
1055 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1056 \
1057 product(ccstr, ErrorFile, NULL, \
1058 "If an error occurs, save the error data to this file " \
1059 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1060 \
1061 product(bool, ExtensiveErrorReports, \
1062 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1063 "Error reports are more extensive.") \
1064 \
1065 product(bool, DisplayVMOutputToStderr, false, \
1066 "If DisplayVMOutput is true, display all VM output to stderr") \
1067 \
1068 product(bool, DisplayVMOutputToStdout, false, \
1069 "If DisplayVMOutput is true, display all VM output to stdout") \
1070 \
1071 product(bool, ErrorFileToStderr, false, \
1072 "If true, error data is printed to stderr instead of a file") \
1073 \
1074 product(bool, ErrorFileToStdout, false, \
1075 "If true, error data is printed to stdout instead of a file") \
1076 \
1077 develop(bool, UseHeavyMonitors, false, \
1078 "(Deprecated) Use heavyweight instead of lightweight Java " \
1079 "monitors") \
1080 \
1081 develop(bool, VerifyHeavyMonitors, false, \
1082 "Checks that no stack locking happens when using " \
1083 "+UseHeavyMonitors") \
1084 \
1085 product(bool, PrintStringTableStatistics, false, \
1086 "print statistics about the StringTable and SymbolTable") \
1087 \
1088 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1089 "verify StringTable contents at exit") \
1090 \
1091 notproduct(bool, PrintSymbolTableSizeHistogram, false, \
1092 "print histogram of the symbol table") \
1093 \
1094 product(ccstr, AbortVMOnException, NULL, DIAGNOSTIC, \
1095 "Call fatal if this exception is thrown. Example: " \
1096 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1097 \
1098 product(ccstr, AbortVMOnExceptionMessage, NULL, DIAGNOSTIC, \
1099 "Call fatal if the exception pointed by AbortVMOnException " \
1100 "has this message") \
1101 \
1102 develop(bool, DebugVtables, false, \
1103 "add debugging code to vtable dispatch") \
1104 \
1105 product(bool, RangeCheckElimination, true, \
1106 "Eliminate range checks") \
1107 \
1108 develop_pd(bool, UncommonNullCast, \
1109 "track occurrences of null in casts; adjust compiler tactics") \
1110 \
1111 develop(bool, TypeProfileCasts, true, \
1112 "treat casts like calls for purposes of type profiling") \
1113 \
1114 develop(bool, TraceLivenessGen, false, \
1115 "Trace the generation of liveness analysis information") \
1116 \
1117 notproduct(bool, TraceLivenessQuery, false, \
1118 "Trace queries of liveness analysis information") \
1119 \
1120 notproduct(bool, CollectIndexSetStatistics, false, \
1121 "Collect information about IndexSets") \
1122 \
1123 develop(intx, FastAllocateSizeLimit, 128*K, \
1124 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1125 "Inline allocations larger than this in doublewords must go slow")\
1126 \
1127 product_pd(bool, CompactStrings, \
1128 "Enable Strings to use single byte chars in backing store") \
1129 \
1130 product_pd(uintx, TypeProfileLevel, \
1131 "=XYZ, with Z: Type profiling of arguments at call; " \
1132 "Y: Type profiling of return value at call; " \
1133 "X: Type profiling of parameters to methods; " \
1134 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1135 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1136 \
1137 product(intx, TypeProfileArgsLimit, 2, \
1138 "max number of call arguments to consider for type profiling") \
1139 range(0, 16) \
1140 \
1141 product(intx, TypeProfileParmsLimit, 2, \
1142 "max number of incoming parameters to consider for type profiling"\
1143 ", -1 for all") \
1144 range(-1, 64) \
1145 \
1146 /* statistics */ \
1147 develop(bool, CountCompiledCalls, false, \
1148 "Count method invocations") \
1149 \
1150 notproduct(bool, ICMissHistogram, false, \
1151 "Produce histogram of IC misses") \
1152 \
1153 /* interpreter */ \
1154 product_pd(bool, RewriteBytecodes, \
1155 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1156 \
1157 product_pd(bool, RewriteFrequentPairs, \
1158 "Rewrite frequently used bytecode pairs into a single bytecode") \
1159 \
1160 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1161 "Print the generated interpreter code") \
1162 \
1163 product(bool, UseInterpreter, true, \
1164 "Use interpreter for non-compiled methods") \
1165 \
1166 develop(bool, UseFastSignatureHandlers, true, \
1167 "Use fast signature handlers for native calls") \
1168 \
1169 product(bool, UseLoopCounter, true, \
1170 "Increment invocation counter on backward branch") \
1171 \
1172 product_pd(bool, UseOnStackReplacement, \
1173 "Use on stack replacement, calls runtime if invoc. counter " \
1174 "overflows in loop") \
1175 \
1176 notproduct(bool, TraceOnStackReplacement, false, \
1177 "Trace on stack replacement") \
1178 \
1179 product_pd(bool, PreferInterpreterNativeStubs, \
1180 "Use always interpreter stubs for native methods invoked via " \
1181 "interpreter") \
1182 \
1183 develop(bool, CountBytecodes, false, \
1184 "Count number of bytecodes executed") \
1185 \
1186 develop(bool, PrintBytecodeHistogram, false, \
1187 "Print histogram of the executed bytecodes") \
1188 \
1189 develop(bool, PrintBytecodePairHistogram, false, \
1190 "Print histogram of the executed bytecode pairs") \
1191 \
1192 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1193 "Print code generated for native method signature handlers") \
1194 \
1195 develop(bool, VerifyOops, false, \
1196 "Do plausibility checks for oops") \
1197 \
1198 develop(bool, CheckUnhandledOops, false, \
1199 "Check for unhandled oops in VM code") \
1200 \
1201 develop(bool, VerifyJNIFields, trueInDebug, \
1202 "Verify jfieldIDs for instance fields") \
1203 \
1204 develop(bool, VerifyFPU, false, \
1205 "Verify FPU state (check for NaN's, etc.)") \
1206 \
1207 develop(bool, VerifyThread, false, \
1208 "Watch the thread register for corruption (SPARC only)") \
1209 \
1210 develop(bool, VerifyActivationFrameSize, false, \
1211 "Verify that activation frame didn't become smaller than its " \
1212 "minimal size") \
1213 \
1214 develop(bool, TraceFrequencyInlining, false, \
1215 "Trace frequency based inlining") \
1216 \
1217 develop_pd(bool, InlineIntrinsics, \
1218 "Inline intrinsics that can be statically resolved") \
1219 \
1220 product_pd(bool, ProfileInterpreter, \
1221 "Profile at the bytecode level during interpretation") \
1222 \
1223 develop_pd(bool, ProfileTraps, \
1224 "Profile deoptimization traps at the bytecode level") \
1225 \
1226 product(intx, ProfileMaturityPercentage, 20, \
1227 "number of method invocations/branches (expressed as % of " \
1228 "CompileThreshold) before using the method's profile") \
1229 range(0, 100) \
1230 \
1231 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1232 "Print the results of +ProfileInterpreter at end of run") \
1233 \
1234 develop(bool, VerifyDataPointer, trueInDebug, \
1235 "Verify the method data pointer during interpreter profiling") \
1236 \
1237 notproduct(bool, CrashGCForDumpingJavaThread, false, \
1238 "Manually make GC thread crash then dump java stack trace; " \
1239 "Test only") \
1240 \
1241 /* compilation */ \
1242 product(bool, UseCompiler, true, \
1243 "Use Just-In-Time compilation") \
1244 \
1245 product(bool, UseCounterDecay, true, \
1246 "Adjust recompilation counters") \
1247 \
1248 develop(intx, CounterHalfLifeTime, 30, \
1249 "Half-life time of invocation counters (in seconds)") \
1250 \
1251 develop(intx, CounterDecayMinIntervalLength, 500, \
1252 "The minimum interval (in milliseconds) between invocation of " \
1253 "CounterDecay") \
1254 \
1255 product(bool, AlwaysCompileLoopMethods, false, \
1256 "When using recompilation, never interpret methods " \
1257 "containing loops") \
1258 \
1259 product(intx, AllocatePrefetchStyle, 1, \
1260 "0 = no prefetch, " \
1261 "1 = generate prefetch instructions for each allocation, " \
1262 "2 = use TLAB watermark to gate allocation prefetch, " \
1263 "3 = generate one prefetch instruction per cache line") \
1264 range(0, 3) \
1265 \
1266 product(intx, AllocatePrefetchDistance, -1, \
1267 "Distance to prefetch ahead of allocation pointer. " \
1268 "-1: use system-specific value (automatically determined") \
1269 constraint(AllocatePrefetchDistanceConstraintFunc,AfterMemoryInit)\
1270 \
1271 product(intx, AllocatePrefetchLines, 3, \
1272 "Number of lines to prefetch ahead of array allocation pointer") \
1273 range(1, 64) \
1274 \
1275 product(intx, AllocateInstancePrefetchLines, 1, \
1276 "Number of lines to prefetch ahead of instance allocation " \
1277 "pointer") \
1278 range(1, 64) \
1279 \
1280 product(intx, AllocatePrefetchStepSize, 16, \
1281 "Step size in bytes of sequential prefetch instructions") \
1282 range(1, 512) \
1283 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1284 \
1285 product(intx, AllocatePrefetchInstr, 0, \
1286 "Select instruction to prefetch ahead of allocation pointer") \
1287 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1288 \
1289 /* deoptimization */ \
1290 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1291 "Trace deoptimization") \
1292 \
1293 develop(bool, PrintDeoptimizationDetails, false, \
1294 "Print more information about deoptimization") \
1295 \
1296 develop(bool, DebugDeoptimization, false, \
1297 "Tracing various information while debugging deoptimization") \
1298 \
1299 product(double, SelfDestructTimer, 0.0, \
1300 "Will cause VM to terminate after a given time " \
1301 "(in fractional minutes) " \
1302 "(0.0 means off)") \
1303 range(0.0, (double)max_intx) \
1304 \
1305 product(intx, MaxJavaStackTraceDepth, 1024, \
1306 "The maximum number of lines in the stack trace for Java " \
1307 "exceptions (0 means all)") \
1308 range(0, max_jint/2) \
1309 \
1310 /* notice: the max range value here is max_jint, not max_intx */ \
1311 /* because of overflow issue */ \
1312 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \
1313 "Guarantee a safepoint (at least) every so many milliseconds " \
1314 "(0 means none)") \
1315 range(0, max_jint) \
1316 \
1317 product(intx, SafepointTimeoutDelay, 10000, \
1318 "Delay in milliseconds for option SafepointTimeout") \
1319 range(0, max_intx LP64_ONLY(/MICROUNITS)) \
1320 \
1321 product(bool, UseSystemMemoryBarrier, false, EXPERIMENTAL, \
1322 "Try to enable system memory barrier") \
1323 \
1324 product(intx, NmethodSweepActivity, 4, \
1325 "Removes cold nmethods from code cache if > 0. Higher values " \
1326 "result in more aggressive sweeping") \
1327 range(0, 2000) \
1328 \
1329 develop(intx, MallocCatchPtr, -1, \
1330 "Hit breakpoint when mallocing/freeing this pointer") \
1331 \
1332 notproduct(ccstrlist, SuppressErrorAt, "", \
1333 "List of assertions (file:line) to muzzle") \
1334 \
1335 develop(intx, StackPrintLimit, 100, \
1336 "number of stack frames to print in VM-level stack dump") \
1337 \
1338 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1339 "max number of compiled code units to print in error log") \
1340 range(0, VMError::max_error_log_print_code) \
1341 \
1342 notproduct(intx, MaxElementPrintSize, 256, \
1343 "maximum number of elements to print") \
1344 \
1345 notproduct(intx, MaxSubklassPrintSize, 4, \
1346 "maximum number of subklasses to print when printing klass") \
1347 \
1348 develop(intx, MaxForceInlineLevel, 100, \
1349 "maximum number of nested calls that are forced for inlining " \
1350 "(using CompileCommand or marked w/ @ForceInline)") \
1351 range(0, max_jint) \
1352 \
1353 develop(intx, MethodHistogramCutoff, 100, \
1354 "The cutoff value for method invocation histogram (+CountCalls)") \
1355 \
1356 develop(intx, DontYieldALotInterval, 10, \
1357 "Interval between which yields will be dropped (milliseconds)") \
1358 \
1359 notproduct(intx, DeoptimizeALotInterval, 5, \
1360 "Number of exits until DeoptimizeALot kicks in") \
1361 \
1362 notproduct(intx, ZombieALotInterval, 5, \
1363 "Number of exits until ZombieALot kicks in") \
1364 \
1365 product(uintx, MallocMaxTestWords, 0, DIAGNOSTIC, \
1366 "If non-zero, maximum number of words that malloc/realloc can " \
1367 "allocate (for testing only)") \
1368 range(0, max_uintx) \
1369 \
1370 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1371 "Limit malloc allocation size from VM. Reaching the limit will " \
1372 "trigger a fatal error. This feature requires " \
1373 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1374 "Usage:" \
1375 "- MallocLimit=<size> to set a total limit. " \
1376 "- MallocLimit=<NMT category>:<size>[,<NMT category>:<size>...] " \
1377 " to set one or more category-specific limits." \
1378 "Example: -XX:MallocLimit=compiler:500m") \
1379 \
1380 product(intx, TypeProfileWidth, 2, \
1381 "Number of receiver types to record in call/cast profile") \
1382 range(0, 8) \
1383 \
1384 develop(intx, BciProfileWidth, 2, \
1385 "Number of return bci's to record in ret profile") \
1386 \
1387 product(intx, PerMethodRecompilationCutoff, 400, \
1388 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1389 range(-1, max_intx) \
1390 \
1391 product(intx, PerBytecodeRecompilationCutoff, 200, \
1392 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1393 range(-1, max_intx) \
1394 \
1395 product(intx, PerMethodTrapLimit, 100, \
1396 "Limit on traps (of one kind) in a method (includes inlines)") \
1397 range(0, max_jint) \
1398 \
1399 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1400 "Limit on speculative traps (of one kind) in a method " \
1401 "(includes inlines)") \
1402 range(0, max_jint) \
1403 \
1404 product(intx, PerBytecodeTrapLimit, 4, \
1405 "Limit on traps (of one kind) at a particular BCI") \
1406 range(0, max_jint) \
1407 \
1408 product(intx, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1409 "Extra method data trap entries for speculation") \
1410 \
1411 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1412 "Ratio of call site execution to caller method invocation") \
1413 \
1414 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1415 "Minimum ratio of call site execution to caller method" \
1416 "invocation to be considered for inlining") \
1417 \
1418 develop(intx, InlineThrowCount, 50, \
1419 "Force inlining of interpreted methods that throw this often") \
1420 range(0, max_jint) \
1421 \
1422 develop(intx, InlineThrowMaxSize, 200, \
1423 "Force inlining of throwing methods smaller than this") \
1424 range(0, max_jint) \
1425 \
1426 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1427 "Initial threshold (in bytes) at which a garbage collection " \
1428 "is done to reduce Metaspace usage") \
1429 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1430 \
1431 product(size_t, MaxMetaspaceSize, max_uintx, \
1432 "Maximum size of Metaspaces (in bytes)") \
1433 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1434 \
1435 product(size_t, CompressedClassSpaceSize, 1*G, \
1436 "Maximum size of class area in Metaspace when compressed " \
1437 "class pointers are used") \
1438 range(1*M, 3*G) \
1439 \
1440 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1441 "Force the class space to be allocated at this address or " \
1442 "fails VM initialization (requires -Xshare=off.") \
1443 \
1444 product(ccstr, MetaspaceReclaimPolicy, "balanced", \
1445 "options: balanced, aggressive, none") \
1446 \
1447 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1448 "Print metaspace statistics upon VM exit.") \
1449 \
1450 develop(bool, MetaspaceGuardAllocations, false, \
1451 "Metapace allocations are guarded.") \
1452 \
1453 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1454 "The minimum percentage of heap free after GC to avoid expansion."\
1455 " For most GCs this applies to the old generation. In G1 and" \
1456 " ParallelGC it applies to the whole heap.") \
1457 range(0, 100) \
1458 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1459 \
1460 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1461 "The maximum percentage of heap free after GC to avoid shrinking."\
1462 " For most GCs this applies to the old generation. In G1 and" \
1463 " ParallelGC it applies to the whole heap.") \
1464 range(0, 100) \
1465 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1466 \
1467 product(bool, ShrinkHeapInSteps, true, \
1468 "When disabled, informs the GC to shrink the java heap directly" \
1469 " to the target size at the next full GC rather than requiring" \
1470 " smaller steps during multiple full GCs.") \
1471 \
1472 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1473 "Number of milliseconds per MB of free space in the heap") \
1474 range(0, max_intx) \
1475 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1476 \
1477 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1478 "The minimum change in heap space due to GC (in bytes)") \
1479 range(0, max_uintx) \
1480 \
1481 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1482 "The minimum expansion of Metaspace (in bytes)") \
1483 range(0, max_uintx) \
1484 \
1485 product(uintx, MaxMetaspaceFreeRatio, 70, \
1486 "The maximum percentage of Metaspace free after GC to avoid " \
1487 "shrinking") \
1488 range(0, 100) \
1489 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1490 \
1491 product(uintx, MinMetaspaceFreeRatio, 40, \
1492 "The minimum percentage of Metaspace free after GC to avoid " \
1493 "expansion") \
1494 range(0, 99) \
1495 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1496 \
1497 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1498 "The maximum expansion of Metaspace without full GC (in bytes)") \
1499 range(0, max_uintx) \
1500 \
1501 /* stack parameters */ \
1502 product_pd(intx, StackYellowPages, \
1503 "Number of yellow zone (recoverable overflows) pages of size " \
1504 "4KB. If pages are bigger yellow zone is aligned up.") \
1505 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1506 \
1507 product_pd(intx, StackRedPages, \
1508 "Number of red zone (unrecoverable overflows) pages of size " \
1509 "4KB. If pages are bigger red zone is aligned up.") \
1510 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1511 \
1512 product_pd(intx, StackReservedPages, \
1513 "Number of reserved zone (reserved to annotated methods) pages" \
1514 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1515 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1516 \
1517 product(bool, RestrictReservedStack, true, \
1518 "Restrict @ReservedStackAccess to trusted classes") \
1519 \
1520 /* greater stack shadow pages can't generate instruction to bang stack */ \
1521 product_pd(intx, StackShadowPages, \
1522 "Number of shadow zone (for overflow checking) pages of size " \
1523 "4KB. If pages are bigger shadow zone is aligned up. " \
1524 "This should exceed the depth of the VM and native call stack.") \
1525 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1526 \
1527 product_pd(intx, ThreadStackSize, \
1528 "Thread Stack Size (in Kbytes)") \
1529 range(0, 1 * M) \
1530 \
1531 product_pd(intx, VMThreadStackSize, \
1532 "Non-Java Thread Stack Size (in Kbytes)") \
1533 range(0, max_intx/(1 * K)) \
1534 \
1535 product_pd(intx, CompilerThreadStackSize, \
1536 "Compiler Thread Stack Size (in Kbytes)") \
1537 range(0, max_intx/(1 * K)) \
1538 \
1539 develop_pd(size_t, JVMInvokeMethodSlack, \
1540 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1541 \
1542 /* code cache parameters */ \
1543 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1544 "Code cache segment size (in bytes) - smallest unit of " \
1545 "allocation") \
1546 range(1, 1024) \
1547 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1548 \
1549 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1550 "Code entry alignment for generated code (in bytes)") \
1551 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1552 \
1553 product_pd(intx, OptoLoopAlignment, \
1554 "Align inner loops to zero relative to this modulus") \
1555 range(1, 128) \
1556 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1557 \
1558 product_pd(uintx, InitialCodeCacheSize, \
1559 "Initial code cache size (in bytes)") \
1560 constraint(VMPageSizeConstraintFunc, AtParse) \
1561 \
1562 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1563 "Minimum code cache size (in bytes) required to start VM.") \
1564 range(0, max_uintx) \
1565 \
1566 product(bool, SegmentedCodeCache, false, \
1567 "Use a segmented code cache") \
1568 \
1569 product_pd(uintx, ReservedCodeCacheSize, \
1570 "Reserved code cache size (in bytes) - maximum code cache size") \
1571 constraint(VMPageSizeConstraintFunc, AtParse) \
1572 \
1573 product_pd(uintx, NonProfiledCodeHeapSize, \
1574 "Size of code heap with non-profiled methods (in bytes)") \
1575 range(0, max_uintx) \
1576 \
1577 product_pd(uintx, ProfiledCodeHeapSize, \
1578 "Size of code heap with profiled methods (in bytes)") \
1579 range(0, max_uintx) \
1580 \
1581 product_pd(uintx, NonNMethodCodeHeapSize, \
1582 "Size of code heap with non-nmethods (in bytes)") \
1583 constraint(VMPageSizeConstraintFunc, AtParse) \
1584 \
1585 product_pd(uintx, CodeCacheExpansionSize, \
1586 "Code cache expansion size (in bytes)") \
1587 range(32*K, max_uintx) \
1588 \
1589 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1590 "Minimum number of segments in a code cache block") \
1591 range(1, 100) \
1592 \
1593 notproduct(bool, ExitOnFullCodeCache, false, \
1594 "Exit the VM if we fill the code cache") \
1595 \
1596 product(bool, UseCodeCacheFlushing, true, \
1597 "Remove cold/old nmethods from the code cache") \
1598 \
1599 product(double, SweeperThreshold, 15.0, \
1600 "Threshold when a code cache unloading GC is invoked." \
1601 "Value is percentage of ReservedCodeCacheSize.") \
1602 range(0.0, 100.0) \
1603 \
1604 product(uintx, StartAggressiveSweepingAt, 10, \
1605 "Start aggressive sweeping if X[%] of the code cache is free." \
1606 "Segmented code cache: X[%] of the non-profiled heap." \
1607 "Non-segmented code cache: X[%] of the total code cache") \
1608 range(0, 100) \
1609 \
1610 /* interpreter debugging */ \
1611 develop(intx, BinarySwitchThreshold, 5, \
1612 "Minimal number of lookupswitch entries for rewriting to binary " \
1613 "switch") \
1614 \
1615 develop(intx, StopInterpreterAt, 0, \
1616 "Stop interpreter execution at specified bytecode number") \
1617 \
1618 develop(intx, TraceBytecodesAt, 0, \
1619 "Trace bytecodes starting with specified bytecode number") \
1620 \
1621 /* Priorities */ \
1622 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1623 \
1624 product(int, ThreadPriorityPolicy, 0, \
1625 "0 : Normal. "\
1626 " VM chooses priorities that are appropriate for normal "\
1627 " applications. "\
1628 " On Windows applications are allowed to use higher native "\
1629 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1630 " not use the highest possible native priority, "\
1631 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1632 " system threads. On Linux thread priorities are ignored "\
1633 " because the OS does not support static priority in "\
1634 " SCHED_OTHER scheduling class which is the only choice for "\
1635 " non-root, non-realtime applications. "\
1636 "1 : Aggressive. "\
1637 " Java thread priorities map over to the entire range of "\
1638 " native thread priorities. Higher Java thread priorities map "\
1639 " to higher native thread priorities. This policy should be "\
1640 " used with care, as sometimes it can cause performance "\
1641 " degradation in the application and/or the entire system. On "\
1642 " Linux/BSD/macOS this policy requires root privilege or an "\
1643 " extended capability.") \
1644 range(0, 1) \
1645 \
1646 product(bool, ThreadPriorityVerbose, false, \
1647 "Print priority changes") \
1648 \
1649 product(int, CompilerThreadPriority, -1, \
1650 "The native priority at which compiler threads should run " \
1651 "(-1 means no change)") \
1652 range(min_jint, max_jint) \
1653 \
1654 product(int, VMThreadPriority, -1, \
1655 "The native priority at which the VM thread should run " \
1656 "(-1 means no change)") \
1657 range(-1, 127) \
1658 \
1659 product(int, JavaPriority1_To_OSPriority, -1, \
1660 "Map Java priorities to OS priorities") \
1661 range(-1, 127) \
1662 \
1663 product(int, JavaPriority2_To_OSPriority, -1, \
1664 "Map Java priorities to OS priorities") \
1665 range(-1, 127) \
1666 \
1667 product(int, JavaPriority3_To_OSPriority, -1, \
1668 "Map Java priorities to OS priorities") \
1669 range(-1, 127) \
1670 \
1671 product(int, JavaPriority4_To_OSPriority, -1, \
1672 "Map Java priorities to OS priorities") \
1673 range(-1, 127) \
1674 \
1675 product(int, JavaPriority5_To_OSPriority, -1, \
1676 "Map Java priorities to OS priorities") \
1677 range(-1, 127) \
1678 \
1679 product(int, JavaPriority6_To_OSPriority, -1, \
1680 "Map Java priorities to OS priorities") \
1681 range(-1, 127) \
1682 \
1683 product(int, JavaPriority7_To_OSPriority, -1, \
1684 "Map Java priorities to OS priorities") \
1685 range(-1, 127) \
1686 \
1687 product(int, JavaPriority8_To_OSPriority, -1, \
1688 "Map Java priorities to OS priorities") \
1689 range(-1, 127) \
1690 \
1691 product(int, JavaPriority9_To_OSPriority, -1, \
1692 "Map Java priorities to OS priorities") \
1693 range(-1, 127) \
1694 \
1695 product(int, JavaPriority10_To_OSPriority,-1, \
1696 "Map Java priorities to OS priorities") \
1697 range(-1, 127) \
1698 \
1699 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1700 "Java thread priority 10 maps to critical scheduling priority") \
1701 \
1702 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1703 "Compiler thread(s) run at critical scheduling priority") \
1704 \
1705 develop(intx, NewCodeParameter, 0, \
1706 "Testing Only: Create a dedicated integer parameter before " \
1707 "putback") \
1708 \
1709 /* new oopmap storage allocation */ \
1710 develop(intx, MinOopMapAllocation, 8, \
1711 "Minimum number of OopMap entries in an OopMapSet") \
1712 \
1713 /* recompilation */ \
1714 product_pd(intx, CompileThreshold, \
1715 "number of interpreted method invocations before (re-)compiling") \
1716 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1717 \
1718 product_pd(bool, TieredCompilation, \
1719 "Enable tiered compilation") \
1720 \
1721 /* Properties for Java libraries */ \
1722 \
1723 product(uint64_t, MaxDirectMemorySize, 0, \
1724 "Maximum total size of NIO direct-buffer allocations. " \
1725 "Ignored if not explicitly set.") \
1726 range(0, max_jlong) \
1727 \
1728 /* Flags used for temporary code during development */ \
1729 \
1730 product(bool, UseNewCode, false, DIAGNOSTIC, \
1731 "Testing Only: Use the new version while testing") \
1732 \
1733 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1734 "Testing Only: Use the new version while testing") \
1735 \
1736 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1737 "Testing Only: Use the new version while testing") \
1738 \
1739 notproduct(bool, UseDebuggerErgo, false, \
1740 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1741 "Turns on the other UseDebuggerErgo* flags") \
1742 \
1743 notproduct(bool, UseDebuggerErgo1, false, \
1744 "Debugging Only: Enable workarounds for debugger induced " \
1745 "os::processor_id() >= os::processor_count() problems") \
1746 \
1747 notproduct(bool, UseDebuggerErgo2, false, \
1748 "Debugging Only: Limit the number of spawned JVM threads") \
1749 \
1750 notproduct(bool, EnableJVMTIStackDepthAsserts, true, \
1751 "Enable JVMTI asserts related to stack depth checks") \
1752 \
1753 /* flags for performance data collection */ \
1754 \
1755 product(bool, UsePerfData, true, \
1756 "Flag to disable jvmstat instrumentation for performance testing "\
1757 "and problem isolation purposes") \
1758 \
1759 product(bool, PerfDataSaveToFile, false, \
1760 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1761 \
1762 product(ccstr, PerfDataSaveFile, NULL, \
1763 "Save PerfData memory to the specified absolute pathname. " \
1764 "The string %p in the file name (if present) " \
1765 "will be replaced by pid") \
1766 \
1767 product(intx, PerfDataSamplingInterval, 50, \
1768 "Data sampling interval (in milliseconds)") \
1769 range(PeriodicTask::min_interval, max_jint) \
1770 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1771 \
1772 product(bool, PerfDisableSharedMem, false, \
1773 "Store performance data in standard memory") \
1774 \
1775 product(int, PerfDataMemorySize, 32*K, \
1776 "Size of performance data memory region. Will be rounded " \
1777 "up to a multiple of the native os page size.") \
1778 range(128, 32*64*K) \
1779 \
1780 product(int, PerfMaxStringConstLength, 1024, \
1781 "Maximum PerfStringConstant string length before truncation") \
1782 range(32, 32*K) \
1783 \
1784 product(bool, PerfAllowAtExitRegistration, false, \
1785 "Allow registration of atexit() methods") \
1786 \
1787 product(bool, PerfBypassFileSystemCheck, false, \
1788 "Bypass Win32 file system criteria checks (Windows Only)") \
1789 \
1790 product(int, UnguardOnExecutionViolation, 0, \
1791 "Unguard page and retry on no-execute fault (Win32 only) " \
1792 "0=off, 1=conservative, 2=aggressive") \
1793 range(0, 2) \
1794 \
1795 /* Serviceability Support */ \
1796 \
1797 product(bool, ManagementServer, false, \
1798 "Create JMX Management Server") \
1799 \
1800 product(bool, DisableAttachMechanism, false, \
1801 "Disable mechanism that allows tools to attach to this VM") \
1802 \
1803 product(bool, StartAttachListener, false, \
1804 "Always start Attach Listener at VM startup") \
1805 \
1806 product(bool, EnableDynamicAgentLoading, true, \
1807 "Allow tools to load agents with the attach mechanism") \
1808 \
1809 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1810 "Print java.util.concurrent locks in thread dump") \
1811 \
1812 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1813 "Print generated stub code for method handles") \
1814 \
1815 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1816 "perform extra checks when constructing method handles") \
1817 \
1818 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1819 "show method handle implementation frames (usually hidden)") \
1820 \
1821 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1822 "show virtual threads' carrier frames in exceptions") \
1823 \
1824 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1825 "trust final non-static declarations for constant folding") \
1826 \
1827 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1828 "Optimize loads from stable fields (marked w/ @Stable)") \
1829 \
1830 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1831 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1832 "resolved before the bootstrap method is called; 1: when a BSM " \
1833 "that may accept a BootstrapCallInfo is detected, use that API " \
1834 "to pass BSM arguments, which allows the BSM to delay their " \
1835 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1836 "via that API, instead of with the eagerly-resolved array.") \
1837 \
1838 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1839 "Causes the VM to pause at startup time and wait for the pause " \
1840 "file to be removed (default: ./vm.paused.<pid>)") \
1841 \
1842 product(ccstr, PauseAtStartupFile, NULL, DIAGNOSTIC, \
1843 "The file to create and for whose removal to await when pausing " \
1844 "at startup. (default: ./vm.paused.<pid>)") \
1845 \
1846 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1847 "Pause and wait for keypress on exit if a debugger is attached") \
1848 \
1849 product(bool, DTraceMethodProbes, false, \
1850 "Enable dtrace tool probes for method-entry and method-exit") \
1851 \
1852 product(bool, DTraceAllocProbes, false, \
1853 "Enable dtrace tool probes for object allocation") \
1854 \
1855 product(bool, DTraceMonitorProbes, false, \
1856 "Enable dtrace tool probes for monitor events") \
1857 \
1858 product(bool, RelaxAccessControlCheck, false, \
1859 "Relax the access control checks in the verifier") \
1860 \
1861 product(uintx, StringTableSize, defaultStringTableSize, \
1862 "Number of buckets in the interned String table " \
1863 "(will be rounded to nearest higher power of 2)") \
1864 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1865 \
1866 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1867 "Number of buckets in the JVM internal Symbol table") \
1868 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1869 \
1870 product(bool, UseStringDeduplication, false, \
1871 "Use string deduplication") \
1872 \
1873 product(uint, StringDeduplicationAgeThreshold, 3, \
1874 "A string must reach this age (or be promoted to an old region) " \
1875 "to be considered for deduplication") \
1876 range(1, markWord::max_age) \
1877 \
1878 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1879 "Approximate initial number of buckets in the table") \
1880 range(1, 1 * G) \
1881 \
1882 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1883 "Entries per bucket above which the table should be expanded") \
1884 range(0.1, 1000.0) \
1885 \
1886 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1887 "Entries per bucket below which the table should be shrunk") \
1888 range(0.01, 100.0) \
1889 \
1890 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1891 "Desired entries per bucket when resizing the table") \
1892 range(0.01, 1000.0) \
1893 \
1894 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1895 "Minimum number of dead table entries for cleaning the table") \
1896 \
1897 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1898 "Minimum percentage of dead table entries for cleaning the table") \
1899 range(1, 100) \
1900 \
1901 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1902 "Force more frequent table resizing") \
1903 \
1904 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1905 "Seed for the table hashing function; 0 requests computed seed") \
1906 \
1907 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1908 "Enable internal testing APIs") \
1909 \
1910 product(size_t, ArrayAllocatorMallocLimit, (size_t)-1, EXPERIMENTAL, \
1911 "Allocation less than this value will be allocated " \
1912 "using malloc. Larger allocations will use mmap.") \
1913 \
1914 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1915 "Accesses to all variables should always be atomic") \
1916 \
1917 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1918 "Use unaligned memory accesses in Unsafe") \
1919 \
1920 product_pd(bool, PreserveFramePointer, \
1921 "Use the FP register for holding the frame pointer " \
1922 "and not as a general purpose register.") \
1923 \
1924 product(size_t, AsyncLogBufferSize, 2*M, \
1925 "Memory budget (in bytes) for the buffer of Asynchronous " \
1926 "Logging (-Xlog:async).") \
1927 range(100*K, 50*M) \
1928 \
1929 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1930 "When a class C is loaded, check that " \
1931 "(1) all intrinsics defined by the VM for class C are present "\
1932 "in the loaded class file and are marked with the " \
1933 "@IntrinsicCandidate annotation, that " \
1934 "(2) there is an intrinsic registered for all loaded methods " \
1935 "that are annotated with the @IntrinsicCandidate annotation, " \
1936 "and that " \
1937 "(3) no orphan methods exist for class C (i.e., methods for " \
1938 "which the VM declares an intrinsic but that are not declared "\
1939 "in the loaded class C. " \
1940 "Check (3) is available only in debug builds.") \
1941 \
1942 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1943 "Threshold small size (in bytes) for clearing arrays. " \
1944 "Anything this size or smaller may get converted to discrete " \
1945 "scalar stores.") \
1946 range(0, max_intx) \
1947 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1948 \
1949 product(ccstr, AllocateHeapAt, NULL, \
1950 "Path to the directory where a temporary file will be created " \
1951 "to use as the backing store for Java Heap.") \
1952 \
1953 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1954 "Enable VM continuations support") \
1955 \
1956 develop(bool, LoomDeoptAfterThaw, false, \
1957 "Deopt stack after thaw") \
1958 \
1959 develop(bool, LoomVerifyAfterThaw, false, \
1960 "Verify stack after thaw") \
1961 \
1962 develop(bool, VerifyContinuations, false, \
1963 "Verify continuation consistency") \
1964 \
1965 develop(bool, UseContinuationFastPath, true, \
1966 "Use fast-path frame walking in continuations") \
1967 \
1968 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1969 "Run periodic metaspace verifications (0 - none, " \
1970 "1 - always, >1 every nth interval)") \
1971 \
1972 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1973 "On internal errors, include registers in error report.") \
1974 \
1975 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1976 "leverage profiling for table/lookup switch") \
1977 \
1978 develop(bool, TraceMemoryWriteback, false, \
1979 "Trace memory writeback operations") \
1980 \
1981 JFR_ONLY(product(bool, FlightRecorder, false, \
1982 "(Deprecated) Enable Flight Recorder")) \
1983 \
1984 JFR_ONLY(product(ccstr, FlightRecorderOptions, NULL, \
1985 "Flight Recorder options")) \
1986 \
1987 JFR_ONLY(product(ccstr, StartFlightRecording, NULL, \
1988 "Start flight recording with options")) \
1989 \
1990 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1991 "Use platform unstable time where supported for timestamps only") \
1992 \
1993 product(bool, EnableValhalla, true, \
1994 "Enable experimental Valhalla features") \
1995 \
1996 product(bool, EnablePrimitiveClasses, false, \
1997 "Enable experimental Valhalla primitive classes") \
1998 \
1999 product_pd(bool, InlineTypePassFieldsAsArgs, \
2000 "Pass each inline type field as an argument at calls") \
2001 \
2002 product_pd(bool, InlineTypeReturnedAsFields, \
2003 "Return fields instead of an inline type reference") \
2004 \
2005 develop(bool, StressInlineTypeReturnedAsFields, false, \
2006 "Stress return of fields instead of an inline type reference") \
2007 \
2008 product(bool, UseArrayMarkWordCheck, NOT_LP64(false) LP64_ONLY(true), \
2009 "Use bits in the mark word to check for flat/null-free arrays") \
2010 \
2011 product(ccstrlist, ForceNonTearable, "", DIAGNOSTIC, \
2012 "List of inline classes which are forced to be atomic " \
2013 "(whitespace and commas separate names, " \
2014 "and leading and trailing stars '*' are wildcards)") \
2015 \
2016 product(bool, UseEmptySlotsInSupers, true, \
2017 "Allow allocating fields in empty slots of super-classes") \
2018 \
2019 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
2020 "Make nmethod barriers deoptimise a lot.") \
2021 \
2022 develop(bool, VerifyCrossModifyFence, \
2023 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
2024 "Mark all threads after a safepoint, and clear on a modify " \
2025 "fence. Add cleanliness checks.") \
2026
2027 // end of RUNTIME_FLAGS
2028
2029 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2030 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2031 DECLARE_FLAGS(RUNTIME_FLAGS)
2032 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2033
2034 #endif // SHARE_RUNTIME_GLOBALS_HPP