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 *
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,
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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(size_t, LargePageSizeInBytes, 0, \
242 "Maximum large page size used (0 will use the default large " \
243 "page size for the environment as the maximum)") \
244 range(0, max_uintx) \
245 \
246 product(size_t, LargePageHeapSizeThreshold, 128*M, \
247 "Use large pages if maximum heap is at least this big") \
248 range(0, max_uintx) \
249 \
250 product(bool, ForceTimeHighResolution, false, \
251 "Using high time resolution (for Win32 only)") \
252 \
253 develop(bool, TracePcPatching, false, \
254 "Trace usage of frame::patch_pc") \
255 \
256 develop(bool, TraceRelocator, false, \
257 "Trace the bytecode relocator") \
258 \
259 \
260 product(bool, SafepointALot, false, DIAGNOSTIC, \
261 "Generate a lot of safepoints. This works with " \
262 "GuaranteedSafepointInterval") \
263 \
264 product(bool, HandshakeALot, false, DIAGNOSTIC, \
265 "Generate a lot of handshakes. This works with " \
266 "GuaranteedSafepointInterval") \
267 \
268 product_pd(bool, BackgroundCompilation, \
269 "A thread requesting compilation is not blocked during " \
270 "compilation") \
271 \
272 product(bool, MethodFlushing, true, \
273 "Reclamation of compiled methods") \
274 \
275 develop(bool, VerifyStack, false, \
276 "Verify stack of each thread when it is entering a runtime call") \
277 \
278 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
279 "Make all non code cache addresses to be unreachable by " \
280 "forcing use of 64bit literal fixups") \
281 \
282 develop(bool, TraceDerivedPointers, false, \
283 "Trace traversal of derived pointers on stack") \
284 \
285 notproduct(bool, TraceCodeBlobStacks, false, \
286 "Trace stack-walk of codeblobs") \
287 \
288 notproduct(bool, PrintRewrites, false, \
289 "Print methods that are being rewritten") \
290 \
291 product(bool, UseInlineCaches, true, \
292 "Use Inline Caches for virtual calls ") \
293 \
294 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
295 "Inline arraycopy native that is known to be part of " \
296 "base library DLL") \
297 \
298 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
299 "Inline Object::hashCode() native that is known to be part " \
300 "of base library DLL") \
301 \
302 product(bool, InlineNatives, true, DIAGNOSTIC, \
303 "Inline natives that are known to be part of base library DLL") \
304 \
305 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
306 "Inline SinD, CosD, etc.") \
307 \
308 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
309 "Inline Class.isInstance, etc") \
310 \
311 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
312 "Inline Thread.currentThread, etc") \
313 \
314 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
315 "Inline memory ops (native methods) from Unsafe") \
316 \
317 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
318 "Use intrinsics for AES versions of crypto") \
319 \
320 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
321 "Use intrinsics for the paralleled version of AES/CTR crypto") \
322 \
323 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
324 "Use intrinsics for MD5 crypto hash function") \
325 \
326 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
327 "Use intrinsics for SHA-1 crypto hash function. " \
328 "Requires that UseSHA is enabled.") \
329 \
330 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
331 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
332 "Requires that UseSHA is enabled.") \
333 \
334 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
335 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
336 "Requires that UseSHA is enabled.") \
337 \
338 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
339 "Use intrinsics for SHA3 crypto hash function. " \
340 "Requires that UseSHA is enabled.") \
341 \
342 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
343 "use intrinsics for java.util.zip.CRC32") \
344 \
345 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
346 "use intrinsics for java.util.zip.CRC32C") \
347 \
348 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
349 "use intrinsics for java.util.zip.Adler32") \
350 \
351 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
352 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
353 \
354 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
355 "Enables intrinsification of Math.copySign") \
356 \
357 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
358 "Enables intrinsification of Math.signum") \
359 \
360 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
361 "do not expand intrinsics whose (internal) names appear here") \
362 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
363 \
364 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
365 "Control intrinsics using a list of +/- (internal) names, " \
366 "separated by commas") \
367 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
368 \
369 develop(bool, TraceCallFixup, false, \
370 "Trace all call fixups") \
371 \
372 develop(bool, DeoptimizeALot, false, \
373 "Deoptimize at every exit from the runtime system") \
374 \
375 notproduct(ccstrlist, DeoptimizeOnlyAt, "", \
376 "A comma separated list of bcis to deoptimize at") \
377 \
378 develop(bool, DeoptimizeRandom, false, \
379 "Deoptimize random frames on random exit from the runtime system")\
380 \
381 notproduct(bool, ZombieALot, false, \
382 "Create non-entrant nmethods at exit from the runtime system") \
383 \
384 notproduct(bool, WalkStackALot, false, \
385 "Trace stack (no print) at every exit from the runtime system") \
386 \
387 develop(bool, DeoptimizeObjectsALot, false, \
388 "For testing purposes concurrent threads revert optimizations " \
389 "based on escape analysis at intervals given with " \
390 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
391 "with DeoptimizeObjectsALotThreadCountSingle and " \
392 "DeoptimizeObjectsALotThreadCountAll.") \
393 \
394 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
395 "Interval for DeoptimizeObjectsALot.") \
396 range(0, max_jlong) \
397 \
398 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
399 "The number of threads that revert optimizations based on " \
400 "escape analysis for a single thread if DeoptimizeObjectsALot " \
401 "is enabled. The target thread is selected round robin." ) \
402 range(0, max_jint) \
403 \
404 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
405 "The number of threads that revert optimizations based on " \
406 "escape analysis for all threads if DeoptimizeObjectsALot " \
407 "is enabled." ) \
408 range(0, max_jint) \
409 \
410 notproduct(bool, VerifyLastFrame, false, \
411 "Verify oops on last frame on entry to VM") \
412 \
413 product(bool, SafepointTimeout, false, \
414 "Time out and warn or fail after SafepointTimeoutDelay " \
415 "milliseconds if failed to reach safepoint") \
416 \
417 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
418 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
419 \
420 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
421 "Abort upon failure to complete VM operation promptly") \
422 \
423 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
424 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
425 range(0, max_intx) \
426 \
427 product(bool, MaxFDLimit, true, \
428 "Bump the number of file descriptors to maximum (Unix only)") \
429 \
430 product(bool, LogEvents, true, DIAGNOSTIC, \
431 "Enable the various ring buffer event logs") \
432 \
433 product(uintx, LogEventsBufferEntries, 20, DIAGNOSTIC, \
434 "Number of ring buffer event logs") \
435 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
436 \
437 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
438 "Enable the Java bytecode verifier for remote classes") \
439 \
440 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
441 "Enable the Java bytecode verifier for local classes") \
442 \
443 develop(bool, VerifyStackAtCalls, false, \
444 "Verify that the stack pointer is unchanged after calls") \
445 \
446 develop(bool, TraceJavaAssertions, false, \
447 "Trace java language assertions") \
448 \
449 notproduct(bool, VerifyCodeCache, false, \
450 "Verify code cache on memory allocation/deallocation") \
451 \
452 develop(bool, UseMallocOnly, false, \
453 "Use only malloc/free for allocation (no resource area/arena). " \
454 "Used to help diagnose memory stomping bugs.") \
455 \
456 develop(bool, ZapResourceArea, trueInDebug, \
457 "Zap freed resource/arena space") \
458 \
459 notproduct(bool, ZapVMHandleArea, trueInDebug, \
460 "Zap freed VM handle space") \
461 \
462 notproduct(bool, ZapStackSegments, trueInDebug, \
463 "Zap allocated/freed stack segments") \
464 \
465 develop(bool, ZapUnusedHeapArea, trueInDebug, \
466 "Zap unused heap space") \
467 \
468 develop(bool, CheckZapUnusedHeapArea, false, \
469 "Check zapping of unused heap space") \
470 \
471 develop(bool, ZapFillerObjects, trueInDebug, \
472 "Zap filler objects") \
473 \
474 product(bool, ExecutingUnitTests, false, \
475 "Whether the JVM is running unit tests or not") \
476 \
477 develop(uint, ErrorHandlerTest, 0, \
478 "If > 0, provokes an error after VM initialization; the value " \
479 "determines which error to provoke. See controlled_crash() " \
480 "in vmError.cpp.") \
481 range(0, 17) \
482 \
483 develop(uint, TestCrashInErrorHandler, 0, \
484 "If > 0, provokes an error inside VM error handler (a secondary " \
485 "crash). see controlled_crash() in vmError.cpp") \
486 range(0, 17) \
487 \
488 develop(bool, TestSafeFetchInErrorHandler, false , \
489 "If true, tests SafeFetch inside error handler.") \
490 \
491 develop(bool, TestUnresponsiveErrorHandler, false, \
492 "If true, simulates an unresponsive error handler.") \
493 \
494 develop(bool, Verbose, false, \
495 "Print additional debugging information from other modes") \
496 \
497 develop(bool, PrintMiscellaneous, false, \
498 "Print uncategorized debugging information (requires +Verbose)") \
499 \
500 develop(bool, WizardMode, false, \
501 "Print much more debugging information") \
502 \
503 product(bool, ShowMessageBoxOnError, false, \
504 "Keep process alive on VM fatal error") \
505 \
506 product(bool, CreateCoredumpOnCrash, true, \
507 "Create core/mini dump on VM fatal error") \
508 \
509 product(uint64_t, ErrorLogTimeout, 2 * 60, \
510 "Timeout, in seconds, to limit the time spent on writing an " \
511 "error log in case of a crash.") \
512 range(0, (uint64_t)max_jlong/1000) \
513 \
514 develop(intx, TraceDwarfLevel, 0, \
515 "Debug levels for the dwarf parser") \
516 range(0, 4) \
517 \
518 product(bool, SuppressFatalErrorMessage, false, \
519 "Report NO fatal error message (avoid deadlock)") \
520 \
521 product(ccstrlist, OnError, "", \
522 "Run user-defined commands on fatal error; see VMError.cpp " \
523 "for examples") \
524 \
525 product(ccstrlist, OnOutOfMemoryError, "", \
526 "Run user-defined commands on first java.lang.OutOfMemoryError " \
527 "thrown from JVM") \
528 \
529 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
530 "Dump heap to file before any major stop-the-world GC") \
531 \
532 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
533 "Dump heap to file after any major stop-the-world GC") \
534 \
535 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
536 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
537 "from JVM") \
538 \
539 product(ccstr, HeapDumpPath, NULL, MANAGEABLE, \
540 "When HeapDumpOnOutOfMemoryError is on, the path (filename or " \
541 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
542 "in the working directory)") \
543 \
544 product(intx, HeapDumpGzipLevel, 0, MANAGEABLE, \
545 "When HeapDumpOnOutOfMemoryError is on, the gzip compression " \
546 "level of the dump file. 0 (the default) disables gzip " \
547 "compression. Otherwise the level must be between 1 and 9.") \
548 range(0, 9) \
549 \
550 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
551 "Native memory tracking options") \
552 \
553 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
554 "Print native memory tracking summary data if it is on") \
555 \
556 product(bool, LogCompilation, false, DIAGNOSTIC, \
557 "Log compilation activity in detail to LogFile") \
558 \
559 product(bool, PrintCompilation, false, \
560 "Print compilations") \
561 \
562 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
563 "Repeat compilation without installing code (number of times)") \
564 range(0, max_jint) \
565 \
566 product(bool, PrintExtendedThreadInfo, false, \
567 "Print more information in thread dump") \
568 \
569 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
570 "0: do not allow scavengable oops in the code cache; " \
571 "1: allow scavenging from the code cache; " \
572 "2: emit as many constants as the compiler can see") \
573 range(0, 2) \
574 \
575 product(bool, AlwaysRestoreFPU, false, \
576 "Restore the FPU control word after every JNI call (expensive)") \
577 \
578 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
579 "Print additional statistics per compilation") \
580 \
581 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
582 "Print code generated for i2c/c2i adapters") \
583 \
584 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
585 "Verify that i2c/c2i adapters are called properly") \
586 \
587 develop(bool, VerifyAdapterSharing, false, \
588 "Verify that the code for shared adapters is the equivalent") \
589 \
590 product(bool, PrintAssembly, false, DIAGNOSTIC, \
591 "Print assembly code (using external disassembler.so)") \
592 \
593 product(ccstr, PrintAssemblyOptions, NULL, DIAGNOSTIC, \
594 "Print options string passed to disassembler.so") \
595 \
596 notproduct(bool, PrintNMethodStatistics, false, \
597 "Print a summary statistic for the generated nmethods") \
598 \
599 product(bool, PrintNMethods, false, DIAGNOSTIC, \
600 "Print assembly code for nmethods when generated") \
601 \
602 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
603 "Print assembly code for native nmethods when generated") \
604 \
605 develop(bool, PrintDebugInfo, false, \
606 "Print debug information for all nmethods when generated") \
607 \
608 develop(bool, PrintRelocations, false, \
609 "Print relocation information for all nmethods when generated") \
610 \
611 develop(bool, PrintDependencies, false, \
612 "Print dependency information for all nmethods when generated") \
613 \
614 develop(bool, PrintExceptionHandlers, false, \
615 "Print exception handler tables for all nmethods when generated") \
616 \
617 develop(bool, StressCompiledExceptionHandlers, false, \
618 "Exercise compiled exception handlers") \
619 \
620 develop(bool, InterceptOSException, false, \
621 "Start debugger when an implicit OS (e.g. NULL) " \
622 "exception happens") \
623 \
624 product(bool, PrintCodeCache, false, \
625 "Print the code cache memory usage when exiting") \
626 \
627 develop(bool, PrintCodeCache2, false, \
628 "Print detailed usage information on the code cache when exiting")\
629 \
630 product(bool, PrintCodeCacheOnCompilation, false, \
631 "Print the code cache memory usage each time a method is " \
632 "compiled") \
633 \
634 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
635 "Print code heap usage statistics on exit and on full condition") \
636 \
637 product(bool, PrintStubCode, false, DIAGNOSTIC, \
638 "Print generated stub code") \
639 \
640 product(bool, StackTraceInThrowable, true, \
641 "Collect backtrace in throwable when exception happens") \
642 \
643 product(bool, OmitStackTraceInFastThrow, true, \
644 "Omit backtraces for some 'hot' exceptions in optimized code") \
645 \
646 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
647 "Show exception messages from RuntimeExceptions that contain " \
648 "snippets of the failing code. Disable this to improve privacy.") \
649 \
650 product(bool, PrintWarnings, true, \
651 "Print JVM warnings to output stream") \
652 \
653 product(bool, RegisterFinalizersAtInit, true, \
654 "Register finalizable objects at end of Object.<init> or " \
655 "after allocation") \
656 \
657 develop(bool, RegisterReferences, true, \
658 "Tell whether the VM should register soft/weak/final/phantom " \
659 "references") \
660 \
661 develop(bool, PrintCodeCacheExtension, false, \
662 "Print extension of code cache") \
663 \
664 develop(bool, UsePrivilegedStack, true, \
665 "Enable the security JVM functions") \
666 \
667 product(bool, ClassUnloading, true, \
668 "Do unloading of classes") \
669 \
670 product(bool, ClassUnloadingWithConcurrentMark, true, \
671 "Do unloading of classes with a concurrent marking cycle") \
672 \
673 notproduct(bool, PrintSystemDictionaryAtExit, false, \
674 "Print the system dictionary at exit") \
675 \
676 notproduct(bool, PrintClassLoaderDataGraphAtExit, false, \
677 "Print the class loader data graph at exit") \
678 \
679 product(bool, DynamicallyResizeSystemDictionaries, true, DIAGNOSTIC, \
680 "Dynamically resize system dictionaries as needed") \
681 \
682 product(bool, AllowParallelDefineClass, false, \
683 "Allow parallel defineClass requests for class loaders " \
684 "registering as parallel capable") \
685 \
686 product_pd(bool, DontYieldALot, \
687 "Throw away obvious excess yield calls") \
688 \
689 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
690 "Disable the use of stack guard pages if the JVM is loaded " \
691 "on the primordial process thread") \
692 \
693 product(bool, PostVirtualThreadCompatibleLifecycleEvents, true, EXPERIMENTAL, \
694 "Post virtual thread ThreadStart and ThreadEnd events for " \
695 "virtual thread unaware agents") \
696 \
697 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
698 "Do JVMTI virtual thread mount/unmount transitions " \
699 "(disabling this flag implies no JVMTI events are posted)") \
700 \
701 /* notice: the max range value here is max_jint, not max_intx */ \
702 /* because of overflow issue */ \
703 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
704 "Async deflate idle monitors every so many milliseconds when " \
705 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
706 range(0, max_jint) \
707 \
708 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
709 "Used to estimate a variable ceiling based on number of threads " \
710 "for use with MonitorUsedDeflationThreshold (0 is off).") \
711 range(0, max_uintx) \
712 \
713 /* notice: the max range value here is max_jint, not max_intx */ \
714 /* because of overflow issue */ \
715 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
716 "The maximum number of monitors to deflate, unlink and delete " \
717 "at one time (minimum is 1024).") \
718 range(1024, max_jint) \
719 \
720 product(intx, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
721 "Percentage of used monitors before triggering deflation (0 is " \
722 "off). The check is performed on GuaranteedSafepointInterval " \
723 "or AsyncDeflationInterval.") \
724 range(0, 100) \
725 \
726 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
727 "Max number of no progress async deflation attempts to tolerate " \
728 "before adjusting the in_use_list_ceiling up (0 is off).") \
729 range(0, max_uintx) \
730 \
731 product(intx, hashCode, 5, EXPERIMENTAL, \
732 "(Unstable) select hashCode generation algorithm") \
733 \
734 product(bool, ReduceSignalUsage, false, \
735 "Reduce the use of OS signals in Java and/or the VM") \
736 \
737 develop(bool, LoadLineNumberTables, true, \
738 "Tell whether the class file parser loads line number tables") \
739 \
740 develop(bool, LoadLocalVariableTables, true, \
741 "Tell whether the class file parser loads local variable tables") \
742 \
743 develop(bool, LoadLocalVariableTypeTables, true, \
744 "Tell whether the class file parser loads local variable type" \
745 "tables") \
746 \
747 product(bool, AllowUserSignalHandlers, false, \
748 "Application will install primary signal handlers for the JVM " \
749 "(Unix only)") \
750 \
751 product(bool, UseSignalChaining, true, \
752 "Use signal-chaining to invoke signal handlers installed " \
753 "by the application (Unix only)") \
754 \
755 product(bool, RestoreMXCSROnJNICalls, false, \
756 "Restore MXCSR when returning from JNI calls") \
757 \
758 product(bool, CheckJNICalls, false, \
759 "Verify all arguments to JNI calls") \
760 \
761 product(bool, UseFastJNIAccessors, true, \
762 "Use optimized versions of Get<Primitive>Field") \
763 \
764 product(intx, MaxJNILocalCapacity, 65536, \
765 "Maximum allowable local JNI handle capacity to " \
766 "EnsureLocalCapacity() and PushLocalFrame(), " \
767 "where <= 0 is unlimited, default: 65536") \
768 range(min_intx, max_intx) \
769 \
770 product(bool, EagerXrunInit, false, \
771 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
772 "but not all -Xrun libraries may support the state of the VM " \
773 "at this time") \
774 \
775 product(bool, PreserveAllAnnotations, false, \
776 "Preserve RuntimeInvisibleAnnotations as well " \
777 "as RuntimeVisibleAnnotations") \
778 \
779 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
780 "Number of OutOfMemoryErrors preallocated with backtrace") \
781 \
782 product(bool, UseXMMForArrayCopy, false, \
783 "Use SSE2 MOVQ instruction for Arraycopy") \
784 \
785 notproduct(bool, PrintFieldLayout, false, \
786 "Print field layout for each class") \
787 \
788 /* Need to limit the extent of the padding to reasonable size. */\
789 /* 8K is well beyond the reasonable HW cache line size, even with */\
790 /* aggressive prefetching, while still leaving the room for segregating */\
791 /* among the distinct pages. */\
792 product(intx, ContendedPaddingWidth, 128, \
793 "How many bytes to pad the fields/classes marked @Contended with")\
794 range(0, 8192) \
795 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
796 \
797 product(bool, EnableContended, true, \
798 "Enable @Contended annotation support") \
799 \
800 product(bool, RestrictContended, true, \
801 "Restrict @Contended to trusted classes") \
802 \
803 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
804 "Detect and take action upon identifying synchronization on " \
805 "value based classes. Modes: " \
806 "0: off; " \
807 "1: exit with fatal error; " \
808 "2: log message to stdout. Output file can be specified with " \
809 " -Xlog:valuebasedclasses. If JFR is running it will " \
810 " also generate JFR events.") \
811 range(0, 2) \
812 \
813 product(bool, ExitOnOutOfMemoryError, false, \
814 "JVM exits on the first occurrence of an out-of-memory error " \
815 "thrown from JVM") \
816 \
817 product(bool, CrashOnOutOfMemoryError, false, \
818 "JVM aborts, producing an error log and core/mini dump, on the " \
819 "first occurrence of an out-of-memory error thrown from JVM") \
820 \
821 /* tracing */ \
822 \
823 develop(bool, StressRewriter, false, \
824 "Stress linktime bytecode rewriting") \
825 \
826 product(ccstr, TraceJVMTI, NULL, \
827 "Trace flags for JVMTI functions and events") \
828 \
829 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
830 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
831 "This option can change an EMCP method into an obsolete method " \
832 "and can affect tests that expect specific methods to be EMCP. " \
833 "This option should be used with caution.") \
834 \
835 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
836 "(Deprecated) Allow redefinition to add and delete private " \
837 "static or final methods for compatibility with old releases") \
838 \
839 develop(bool, TraceBytecodes, false, \
840 "Trace bytecode execution") \
841 \
842 develop(bool, TraceICs, false, \
843 "Trace inline cache changes") \
844 \
845 notproduct(bool, TraceInvocationCounterOverflow, false, \
846 "Trace method invocation counter overflow") \
847 \
848 develop(bool, TraceInlineCacheClearing, false, \
849 "Trace clearing of inline caches in nmethods") \
850 \
851 develop(bool, TraceDependencies, false, \
852 "Trace dependencies") \
853 \
854 develop(bool, VerifyDependencies, trueInDebug, \
855 "Exercise and verify the compilation dependency mechanism") \
856 \
857 develop(bool, TraceNewOopMapGeneration, false, \
858 "Trace OopMapGeneration") \
859 \
860 develop(bool, TraceNewOopMapGenerationDetailed, false, \
861 "Trace OopMapGeneration: print detailed cell states") \
862 \
863 develop(bool, TimeOopMap, false, \
864 "Time calls to GenerateOopMap::compute_map() in sum") \
865 \
866 develop(bool, TimeOopMap2, false, \
867 "Time calls to GenerateOopMap::compute_map() individually") \
868 \
869 develop(bool, TraceOopMapRewrites, false, \
870 "Trace rewriting of methods during oop map generation") \
871 \
872 develop(bool, TraceICBuffer, false, \
873 "Trace usage of IC buffer") \
874 \
875 develop(bool, TraceCompiledIC, false, \
876 "Trace changes of compiled IC") \
877 \
878 develop(bool, FLSVerifyDictionary, false, \
879 "Do lots of (expensive) FLS dictionary verification") \
880 \
881 \
882 notproduct(bool, CheckMemoryInitialization, false, \
883 "Check memory initialization") \
884 \
885 product(uintx, ProcessDistributionStride, 4, \
886 "Stride through processors when distributing processes") \
887 range(0, max_juint) \
888 \
889 develop(bool, TraceFinalizerRegistration, false, \
890 "Trace registration of final references") \
891 \
892 product(bool, IgnoreEmptyClassPaths, false, \
893 "Ignore empty path elements in -classpath") \
894 \
895 product(bool, PrintHeapAtSIGBREAK, true, \
896 "Print heap layout in response to SIGBREAK") \
897 \
898 product(bool, PrintClassHistogram, false, MANAGEABLE, \
899 "Print a histogram of class instances") \
900 \
901 product(double, ObjectCountCutOffPercent, 0.5, EXPERIMENTAL, \
902 "The percentage of the used heap that the instances of a class " \
903 "must occupy for the class to generate a trace event") \
904 range(0.0, 100.0) \
905 \
906 /* JVMTI heap profiling */ \
907 \
908 product(bool, VerifyBeforeIteration, false, DIAGNOSTIC, \
909 "Verify memory system before JVMTI iteration") \
910 \
911 /* compiler */ \
912 \
913 /* notice: the max range value here is max_jint, not max_intx */ \
914 /* because of overflow issue */ \
915 product(intx, CICompilerCount, CI_COMPILER_COUNT, \
916 "Number of compiler threads to run") \
917 range(0, max_jint) \
918 constraint(CICompilerCountConstraintFunc, AfterErgo) \
919 \
920 product(bool, UseDynamicNumberOfCompilerThreads, true, \
921 "Dynamically choose the number of parallel compiler threads") \
922 \
923 product(bool, ReduceNumberOfCompilerThreads, true, DIAGNOSTIC, \
924 "Reduce the number of parallel compiler threads when they " \
925 "are not used") \
926 \
927 product(bool, TraceCompilerThreads, false, DIAGNOSTIC, \
928 "Trace creation and removal of compiler threads") \
929 \
930 develop(bool, InjectCompilerCreationFailure, false, \
931 "Inject thread creation failures for " \
932 "UseDynamicNumberOfCompilerThreads") \
933 \
934 develop(bool, GenerateSynchronizationCode, true, \
935 "generate locking/unlocking code for synchronized methods and " \
936 "monitors") \
937 \
938 develop(bool, GenerateRangeChecks, true, \
939 "Generate range checks for array accesses") \
940 \
941 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
942 "Generate code for implicit null checks") \
943 \
944 product_pd(bool, TrapBasedNullChecks, \
945 "Generate code for null checks that uses a cmp and trap " \
946 "instruction raising SIGTRAP. This is only used if an access to" \
947 "null (+offset) will not raise a SIGSEGV, i.e.," \
948 "ImplicitNullChecks don't work (PPC64).") \
949 \
950 product(bool, EnableThreadSMRExtraValidityChecks, true, DIAGNOSTIC, \
951 "Enable Thread SMR extra validity checks") \
952 \
953 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
954 "Enable Thread SMR Statistics") \
955 \
956 product(bool, UseNotificationThread, true, \
957 "Use Notification Thread") \
958 \
959 product(bool, Inline, true, \
960 "Enable inlining") \
961 \
962 product(bool, ClipInlining, true, \
963 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
964 \
965 develop(bool, UseCHA, true, \
966 "Enable CHA") \
967 \
968 product(bool, UseVtableBasedCHA, true, DIAGNOSTIC, \
969 "Use vtable information during CHA") \
970 \
971 product(bool, UseTypeProfile, true, \
972 "Check interpreter profile for historically monomorphic calls") \
973 \
974 product(bool, PrintInlining, false, DIAGNOSTIC, \
975 "Print inlining optimizations") \
976 \
977 product(bool, UsePopCountInstruction, false, \
978 "Use population count instruction") \
979 \
980 develop(bool, TraceMethodReplacement, false, \
981 "Print when methods are replaced do to recompilation") \
982 \
983 product(bool, PrintMethodFlushingStatistics, false, DIAGNOSTIC, \
984 "print statistics about method flushing") \
985 \
986 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
987 "Minimum number of sweeper passes before an nmethod " \
988 "can be flushed") \
989 range(0, max_intx) \
990 \
991 develop(bool, StressCodeBuffers, false, \
992 "Exercise code buffer expansion and other rare state changes") \
993 \
994 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
995 "Generate extra debugging information for non-safepoints in " \
996 "nmethods") \
997 \
998 product(bool, PrintVMOptions, false, \
999 "Print flags that appeared on the command line") \
1000 \
1001 product(bool, IgnoreUnrecognizedVMOptions, false, \
1002 "Ignore unrecognized VM options") \
1003 \
1004 product(bool, PrintCommandLineFlags, false, \
1005 "Print flags specified on command line or set by ergonomics") \
1006 \
1007 product(bool, PrintFlagsInitial, false, \
1008 "Print all VM flags before argument processing and exit VM") \
1009 \
1010 product(bool, PrintFlagsFinal, false, \
1011 "Print all VM flags after argument and ergonomic processing") \
1012 \
1013 notproduct(bool, PrintFlagsWithComments, false, \
1014 "Print all VM flags with default values and descriptions and " \
1015 "exit") \
1016 \
1017 product(bool, PrintFlagsRanges, false, \
1018 "Print VM flags and their ranges") \
1019 \
1020 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1021 "Use a mutex to serialize output to tty and LogFile") \
1022 \
1023 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1024 "Display all VM output on the tty, independently of LogVMOutput") \
1025 \
1026 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1027 "Save VM output to LogFile") \
1028 \
1029 product(ccstr, LogFile, NULL, DIAGNOSTIC, \
1030 "If LogVMOutput or LogCompilation is on, save VM output to " \
1031 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1032 \
1033 product(ccstr, ErrorFile, NULL, \
1034 "If an error occurs, save the error data to this file " \
1035 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1036 \
1037 product(bool, ExtensiveErrorReports, \
1038 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1039 "Error reports are more extensive.") \
1040 \
1041 product(bool, DisplayVMOutputToStderr, false, \
1042 "If DisplayVMOutput is true, display all VM output to stderr") \
1043 \
1044 product(bool, DisplayVMOutputToStdout, false, \
1045 "If DisplayVMOutput is true, display all VM output to stdout") \
1046 \
1047 product(bool, ErrorFileToStderr, false, \
1048 "If true, error data is printed to stderr instead of a file") \
1049 \
1050 product(bool, ErrorFileToStdout, false, \
1051 "If true, error data is printed to stdout instead of a file") \
1052 \
1053 develop(bool, UseHeavyMonitors, false, \
1054 "(Deprecated) Use heavyweight instead of lightweight Java " \
1055 "monitors") \
1056 \
1057 develop(bool, VerifyHeavyMonitors, false, \
1058 "Checks that no stack locking happens when using " \
1059 "+UseHeavyMonitors") \
1060 \
1061 product(bool, PrintStringTableStatistics, false, \
1062 "print statistics about the StringTable and SymbolTable") \
1063 \
1064 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1065 "verify StringTable contents at exit") \
1066 \
1067 notproduct(bool, PrintSymbolTableSizeHistogram, false, \
1068 "print histogram of the symbol table") \
1069 \
1070 product(ccstr, AbortVMOnException, NULL, DIAGNOSTIC, \
1071 "Call fatal if this exception is thrown. Example: " \
1072 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1073 \
1074 product(ccstr, AbortVMOnExceptionMessage, NULL, DIAGNOSTIC, \
1075 "Call fatal if the exception pointed by AbortVMOnException " \
1076 "has this message") \
1077 \
1078 develop(bool, DebugVtables, false, \
1079 "add debugging code to vtable dispatch") \
1080 \
1081 product(bool, RangeCheckElimination, true, \
1082 "Eliminate range checks") \
1083 \
1084 develop_pd(bool, UncommonNullCast, \
1085 "track occurrences of null in casts; adjust compiler tactics") \
1086 \
1087 develop(bool, TypeProfileCasts, true, \
1088 "treat casts like calls for purposes of type profiling") \
1089 \
1090 develop(bool, TraceLivenessGen, false, \
1091 "Trace the generation of liveness analysis information") \
1092 \
1093 notproduct(bool, TraceLivenessQuery, false, \
1094 "Trace queries of liveness analysis information") \
1095 \
1096 notproduct(bool, CollectIndexSetStatistics, false, \
1097 "Collect information about IndexSets") \
1098 \
1099 develop(intx, FastAllocateSizeLimit, 128*K, \
1100 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1101 "Inline allocations larger than this in doublewords must go slow")\
1102 \
1103 product_pd(bool, CompactStrings, \
1104 "Enable Strings to use single byte chars in backing store") \
1105 \
1106 product_pd(uintx, TypeProfileLevel, \
1107 "=XYZ, with Z: Type profiling of arguments at call; " \
1108 "Y: Type profiling of return value at call; " \
1109 "X: Type profiling of parameters to methods; " \
1110 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1111 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1112 \
1113 product(intx, TypeProfileArgsLimit, 2, \
1114 "max number of call arguments to consider for type profiling") \
1115 range(0, 16) \
1116 \
1117 product(intx, TypeProfileParmsLimit, 2, \
1118 "max number of incoming parameters to consider for type profiling"\
1119 ", -1 for all") \
1120 range(-1, 64) \
1121 \
1122 /* statistics */ \
1123 develop(bool, CountCompiledCalls, false, \
1124 "Count method invocations") \
1125 \
1126 notproduct(bool, ICMissHistogram, false, \
1127 "Produce histogram of IC misses") \
1128 \
1129 /* interpreter */ \
1130 product_pd(bool, RewriteBytecodes, \
1131 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1132 \
1133 product_pd(bool, RewriteFrequentPairs, \
1134 "Rewrite frequently used bytecode pairs into a single bytecode") \
1135 \
1136 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1137 "Print the generated interpreter code") \
1138 \
1139 product(bool, UseInterpreter, true, \
1140 "Use interpreter for non-compiled methods") \
1141 \
1142 develop(bool, UseFastSignatureHandlers, true, \
1143 "Use fast signature handlers for native calls") \
1144 \
1145 product(bool, UseLoopCounter, true, \
1146 "Increment invocation counter on backward branch") \
1147 \
1148 product_pd(bool, UseOnStackReplacement, \
1149 "Use on stack replacement, calls runtime if invoc. counter " \
1150 "overflows in loop") \
1151 \
1152 notproduct(bool, TraceOnStackReplacement, false, \
1153 "Trace on stack replacement") \
1154 \
1155 product_pd(bool, PreferInterpreterNativeStubs, \
1156 "Use always interpreter stubs for native methods invoked via " \
1157 "interpreter") \
1158 \
1159 develop(bool, CountBytecodes, false, \
1160 "Count number of bytecodes executed") \
1161 \
1162 develop(bool, PrintBytecodeHistogram, false, \
1163 "Print histogram of the executed bytecodes") \
1164 \
1165 develop(bool, PrintBytecodePairHistogram, false, \
1166 "Print histogram of the executed bytecode pairs") \
1167 \
1168 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1169 "Print code generated for native method signature handlers") \
1170 \
1171 develop(bool, VerifyOops, false, \
1172 "Do plausibility checks for oops") \
1173 \
1174 develop(bool, CheckUnhandledOops, false, \
1175 "Check for unhandled oops in VM code") \
1176 \
1177 develop(bool, VerifyJNIFields, trueInDebug, \
1178 "Verify jfieldIDs for instance fields") \
1179 \
1180 develop(bool, VerifyFPU, false, \
1181 "Verify FPU state (check for NaN's, etc.)") \
1182 \
1183 develop(bool, VerifyThread, false, \
1184 "Watch the thread register for corruption (SPARC only)") \
1185 \
1186 develop(bool, VerifyActivationFrameSize, false, \
1187 "Verify that activation frame didn't become smaller than its " \
1188 "minimal size") \
1189 \
1190 develop(bool, TraceFrequencyInlining, false, \
1191 "Trace frequency based inlining") \
1192 \
1193 develop_pd(bool, InlineIntrinsics, \
1194 "Inline intrinsics that can be statically resolved") \
1195 \
1196 product_pd(bool, ProfileInterpreter, \
1197 "Profile at the bytecode level during interpretation") \
1198 \
1199 develop_pd(bool, ProfileTraps, \
1200 "Profile deoptimization traps at the bytecode level") \
1201 \
1202 product(intx, ProfileMaturityPercentage, 20, \
1203 "number of method invocations/branches (expressed as % of " \
1204 "CompileThreshold) before using the method's profile") \
1205 range(0, 100) \
1206 \
1207 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1208 "Print the results of +ProfileInterpreter at end of run") \
1209 \
1210 develop(bool, VerifyDataPointer, trueInDebug, \
1211 "Verify the method data pointer during interpreter profiling") \
1212 \
1213 notproduct(bool, CrashGCForDumpingJavaThread, false, \
1214 "Manually make GC thread crash then dump java stack trace; " \
1215 "Test only") \
1216 \
1217 /* compilation */ \
1218 product(bool, UseCompiler, true, \
1219 "Use Just-In-Time compilation") \
1220 \
1221 product(bool, UseCounterDecay, true, \
1222 "Adjust recompilation counters") \
1223 \
1224 develop(intx, CounterHalfLifeTime, 30, \
1225 "Half-life time of invocation counters (in seconds)") \
1226 \
1227 develop(intx, CounterDecayMinIntervalLength, 500, \
1228 "The minimum interval (in milliseconds) between invocation of " \
1229 "CounterDecay") \
1230 \
1231 product(bool, AlwaysCompileLoopMethods, false, \
1232 "When using recompilation, never interpret methods " \
1233 "containing loops") \
1234 \
1235 product(intx, AllocatePrefetchStyle, 1, \
1236 "0 = no prefetch, " \
1237 "1 = generate prefetch instructions for each allocation, " \
1238 "2 = use TLAB watermark to gate allocation prefetch, " \
1239 "3 = generate one prefetch instruction per cache line") \
1240 range(0, 3) \
1241 \
1242 product(intx, AllocatePrefetchDistance, -1, \
1243 "Distance to prefetch ahead of allocation pointer. " \
1244 "-1: use system-specific value (automatically determined") \
1245 constraint(AllocatePrefetchDistanceConstraintFunc,AfterMemoryInit)\
1246 \
1247 product(intx, AllocatePrefetchLines, 3, \
1248 "Number of lines to prefetch ahead of array allocation pointer") \
1249 range(1, 64) \
1250 \
1251 product(intx, AllocateInstancePrefetchLines, 1, \
1252 "Number of lines to prefetch ahead of instance allocation " \
1253 "pointer") \
1254 range(1, 64) \
1255 \
1256 product(intx, AllocatePrefetchStepSize, 16, \
1257 "Step size in bytes of sequential prefetch instructions") \
1258 range(1, 512) \
1259 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1260 \
1261 product(intx, AllocatePrefetchInstr, 0, \
1262 "Select instruction to prefetch ahead of allocation pointer") \
1263 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1264 \
1265 /* deoptimization */ \
1266 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1267 "Trace deoptimization") \
1268 \
1269 develop(bool, PrintDeoptimizationDetails, false, \
1270 "Print more information about deoptimization") \
1271 \
1272 develop(bool, DebugDeoptimization, false, \
1273 "Tracing various information while debugging deoptimization") \
1274 \
1275 product(double, SelfDestructTimer, 0.0, \
1276 "Will cause VM to terminate after a given time " \
1277 "(in fractional minutes) " \
1278 "(0.0 means off)") \
1279 range(0.0, (double)max_intx) \
1280 \
1281 product(intx, MaxJavaStackTraceDepth, 1024, \
1282 "The maximum number of lines in the stack trace for Java " \
1283 "exceptions (0 means all)") \
1284 range(0, max_jint/2) \
1285 \
1286 /* notice: the max range value here is max_jint, not max_intx */ \
1287 /* because of overflow issue */ \
1288 product(intx, GuaranteedSafepointInterval, 1000, DIAGNOSTIC, \
1289 "Guarantee a safepoint (at least) every so many milliseconds " \
1290 "(0 means none)") \
1291 range(0, max_jint) \
1292 \
1293 product(intx, SafepointTimeoutDelay, 10000, \
1294 "Delay in milliseconds for option SafepointTimeout") \
1295 range(0, max_intx LP64_ONLY(/MICROUNITS)) \
1296 \
1297 product(bool, UseSystemMemoryBarrier, false, EXPERIMENTAL, \
1298 "Try to enable system memory barrier") \
1299 \
1300 product(intx, NmethodSweepActivity, 4, \
1301 "Removes cold nmethods from code cache if > 0. Higher values " \
1302 "result in more aggressive sweeping") \
1303 range(0, 2000) \
1304 \
1305 develop(intx, MallocCatchPtr, -1, \
1306 "Hit breakpoint when mallocing/freeing this pointer") \
1307 \
1308 notproduct(ccstrlist, SuppressErrorAt, "", \
1309 "List of assertions (file:line) to muzzle") \
1310 \
1311 develop(intx, StackPrintLimit, 100, \
1312 "number of stack frames to print in VM-level stack dump") \
1313 \
1314 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1315 "max number of compiled code units to print in error log") \
1316 range(0, VMError::max_error_log_print_code) \
1317 \
1318 notproduct(intx, MaxElementPrintSize, 256, \
1319 "maximum number of elements to print") \
1320 \
1321 notproduct(intx, MaxSubklassPrintSize, 4, \
1322 "maximum number of subklasses to print when printing klass") \
1323 \
1324 develop(intx, MaxForceInlineLevel, 100, \
1325 "maximum number of nested calls that are forced for inlining " \
1326 "(using CompileCommand or marked w/ @ForceInline)") \
1327 range(0, max_jint) \
1328 \
1329 develop(intx, MethodHistogramCutoff, 100, \
1330 "The cutoff value for method invocation histogram (+CountCalls)") \
1331 \
1332 develop(intx, DontYieldALotInterval, 10, \
1333 "Interval between which yields will be dropped (milliseconds)") \
1334 \
1335 notproduct(intx, DeoptimizeALotInterval, 5, \
1336 "Number of exits until DeoptimizeALot kicks in") \
1337 \
1338 notproduct(intx, ZombieALotInterval, 5, \
1339 "Number of exits until ZombieALot kicks in") \
1340 \
1341 product(uintx, MallocMaxTestWords, 0, DIAGNOSTIC, \
1342 "If non-zero, maximum number of words that malloc/realloc can " \
1343 "allocate (for testing only)") \
1344 range(0, max_uintx) \
1345 \
1346 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1347 "Limit malloc allocation size from VM. Reaching the limit will " \
1348 "trigger a fatal error. This feature requires " \
1349 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1350 "Usage:" \
1351 "- MallocLimit=<size> to set a total limit. " \
1352 "- MallocLimit=<NMT category>:<size>[,<NMT category>:<size>...] " \
1353 " to set one or more category-specific limits." \
1354 "Example: -XX:MallocLimit=compiler:500m") \
1355 \
1356 product(intx, TypeProfileWidth, 2, \
1357 "Number of receiver types to record in call/cast profile") \
1358 range(0, 8) \
1359 \
1360 develop(intx, BciProfileWidth, 2, \
1361 "Number of return bci's to record in ret profile") \
1362 \
1363 product(intx, PerMethodRecompilationCutoff, 400, \
1364 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1365 range(-1, max_intx) \
1366 \
1367 product(intx, PerBytecodeRecompilationCutoff, 200, \
1368 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1369 range(-1, max_intx) \
1370 \
1371 product(intx, PerMethodTrapLimit, 100, \
1372 "Limit on traps (of one kind) in a method (includes inlines)") \
1373 range(0, max_jint) \
1374 \
1375 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1376 "Limit on speculative traps (of one kind) in a method " \
1377 "(includes inlines)") \
1378 range(0, max_jint) \
1379 \
1380 product(intx, PerBytecodeTrapLimit, 4, \
1381 "Limit on traps (of one kind) at a particular BCI") \
1382 range(0, max_jint) \
1383 \
1384 product(intx, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1385 "Extra method data trap entries for speculation") \
1386 \
1387 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1388 "Ratio of call site execution to caller method invocation") \
1389 \
1390 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1391 "Minimum ratio of call site execution to caller method" \
1392 "invocation to be considered for inlining") \
1393 \
1394 develop(intx, InlineThrowCount, 50, \
1395 "Force inlining of interpreted methods that throw this often") \
1396 range(0, max_jint) \
1397 \
1398 develop(intx, InlineThrowMaxSize, 200, \
1399 "Force inlining of throwing methods smaller than this") \
1400 range(0, max_jint) \
1401 \
1402 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1403 "Initial threshold (in bytes) at which a garbage collection " \
1404 "is done to reduce Metaspace usage") \
1405 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1406 \
1407 product(size_t, MaxMetaspaceSize, max_uintx, \
1408 "Maximum size of Metaspaces (in bytes)") \
1409 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1410 \
1411 product(size_t, CompressedClassSpaceSize, 1*G, \
1412 "Maximum size of class area in Metaspace when compressed " \
1413 "class pointers are used") \
1414 range(1*M, 3*G) \
1415 \
1416 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1417 "Force the class space to be allocated at this address or " \
1418 "fails VM initialization (requires -Xshare=off.") \
1419 \
1420 product(ccstr, MetaspaceReclaimPolicy, "balanced", \
1421 "options: balanced, aggressive, none") \
1422 \
1423 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1424 "Print metaspace statistics upon VM exit.") \
1425 \
1426 develop(bool, MetaspaceGuardAllocations, false, \
1427 "Metapace allocations are guarded.") \
1428 \
1429 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1430 "The minimum percentage of heap free after GC to avoid expansion."\
1431 " For most GCs this applies to the old generation. In G1 and" \
1432 " ParallelGC it applies to the whole heap.") \
1433 range(0, 100) \
1434 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1435 \
1436 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1437 "The maximum percentage of heap free after GC to avoid shrinking."\
1438 " For most GCs this applies to the old generation. In G1 and" \
1439 " ParallelGC it applies to the whole heap.") \
1440 range(0, 100) \
1441 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1442 \
1443 product(bool, ShrinkHeapInSteps, true, \
1444 "When disabled, informs the GC to shrink the java heap directly" \
1445 " to the target size at the next full GC rather than requiring" \
1446 " smaller steps during multiple full GCs.") \
1447 \
1448 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1449 "Number of milliseconds per MB of free space in the heap") \
1450 range(0, max_intx) \
1451 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1452 \
1453 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1454 "The minimum change in heap space due to GC (in bytes)") \
1455 range(0, max_uintx) \
1456 \
1457 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1458 "The minimum expansion of Metaspace (in bytes)") \
1459 range(0, max_uintx) \
1460 \
1461 product(uintx, MaxMetaspaceFreeRatio, 70, \
1462 "The maximum percentage of Metaspace free after GC to avoid " \
1463 "shrinking") \
1464 range(0, 100) \
1465 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1466 \
1467 product(uintx, MinMetaspaceFreeRatio, 40, \
1468 "The minimum percentage of Metaspace free after GC to avoid " \
1469 "expansion") \
1470 range(0, 99) \
1471 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1472 \
1473 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1474 "The maximum expansion of Metaspace without full GC (in bytes)") \
1475 range(0, max_uintx) \
1476 \
1477 /* stack parameters */ \
1478 product_pd(intx, StackYellowPages, \
1479 "Number of yellow zone (recoverable overflows) pages of size " \
1480 "4KB. If pages are bigger yellow zone is aligned up.") \
1481 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1482 \
1483 product_pd(intx, StackRedPages, \
1484 "Number of red zone (unrecoverable overflows) pages of size " \
1485 "4KB. If pages are bigger red zone is aligned up.") \
1486 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1487 \
1488 product_pd(intx, StackReservedPages, \
1489 "Number of reserved zone (reserved to annotated methods) pages" \
1490 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1491 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1492 \
1493 product(bool, RestrictReservedStack, true, \
1494 "Restrict @ReservedStackAccess to trusted classes") \
1495 \
1496 /* greater stack shadow pages can't generate instruction to bang stack */ \
1497 product_pd(intx, StackShadowPages, \
1498 "Number of shadow zone (for overflow checking) pages of size " \
1499 "4KB. If pages are bigger shadow zone is aligned up. " \
1500 "This should exceed the depth of the VM and native call stack.") \
1501 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1502 \
1503 product_pd(intx, ThreadStackSize, \
1504 "Thread Stack Size (in Kbytes)") \
1505 range(0, 1 * M) \
1506 \
1507 product_pd(intx, VMThreadStackSize, \
1508 "Non-Java Thread Stack Size (in Kbytes)") \
1509 range(0, max_intx/(1 * K)) \
1510 \
1511 product_pd(intx, CompilerThreadStackSize, \
1512 "Compiler Thread Stack Size (in Kbytes)") \
1513 range(0, max_intx/(1 * K)) \
1514 \
1515 develop_pd(size_t, JVMInvokeMethodSlack, \
1516 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1517 \
1518 /* code cache parameters */ \
1519 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1520 "Code cache segment size (in bytes) - smallest unit of " \
1521 "allocation") \
1522 range(1, 1024) \
1523 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1524 \
1525 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1526 "Code entry alignment for generated code (in bytes)") \
1527 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1528 \
1529 product_pd(intx, OptoLoopAlignment, \
1530 "Align inner loops to zero relative to this modulus") \
1531 range(1, 128) \
1532 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1533 \
1534 product_pd(uintx, InitialCodeCacheSize, \
1535 "Initial code cache size (in bytes)") \
1536 constraint(VMPageSizeConstraintFunc, AtParse) \
1537 \
1538 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1539 "Minimum code cache size (in bytes) required to start VM.") \
1540 range(0, max_uintx) \
1541 \
1542 product(bool, SegmentedCodeCache, false, \
1543 "Use a segmented code cache") \
1544 \
1545 product_pd(uintx, ReservedCodeCacheSize, \
1546 "Reserved code cache size (in bytes) - maximum code cache size") \
1547 constraint(VMPageSizeConstraintFunc, AtParse) \
1548 \
1549 product_pd(uintx, NonProfiledCodeHeapSize, \
1550 "Size of code heap with non-profiled methods (in bytes)") \
1551 range(0, max_uintx) \
1552 \
1553 product_pd(uintx, ProfiledCodeHeapSize, \
1554 "Size of code heap with profiled methods (in bytes)") \
1555 range(0, max_uintx) \
1556 \
1557 product_pd(uintx, NonNMethodCodeHeapSize, \
1558 "Size of code heap with non-nmethods (in bytes)") \
1559 constraint(VMPageSizeConstraintFunc, AtParse) \
1560 \
1561 product_pd(uintx, CodeCacheExpansionSize, \
1562 "Code cache expansion size (in bytes)") \
1563 range(32*K, max_uintx) \
1564 \
1565 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1566 "Minimum number of segments in a code cache block") \
1567 range(1, 100) \
1568 \
1569 notproduct(bool, ExitOnFullCodeCache, false, \
1570 "Exit the VM if we fill the code cache") \
1571 \
1572 product(bool, UseCodeCacheFlushing, true, \
1573 "Remove cold/old nmethods from the code cache") \
1574 \
1575 product(double, SweeperThreshold, 15.0, \
1576 "Threshold when a code cache unloading GC is invoked." \
1577 "Value is percentage of ReservedCodeCacheSize.") \
1578 range(0.0, 100.0) \
1579 \
1580 product(uintx, StartAggressiveSweepingAt, 10, \
1581 "Start aggressive sweeping if X[%] of the code cache is free." \
1582 "Segmented code cache: X[%] of the non-profiled heap." \
1583 "Non-segmented code cache: X[%] of the total code cache") \
1584 range(0, 100) \
1585 \
1586 /* interpreter debugging */ \
1587 develop(intx, BinarySwitchThreshold, 5, \
1588 "Minimal number of lookupswitch entries for rewriting to binary " \
1589 "switch") \
1590 \
1591 develop(intx, StopInterpreterAt, 0, \
1592 "Stop interpreter execution at specified bytecode number") \
1593 \
1594 develop(intx, TraceBytecodesAt, 0, \
1595 "Trace bytecodes starting with specified bytecode number") \
1596 \
1597 /* Priorities */ \
1598 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1599 \
1600 product(int, ThreadPriorityPolicy, 0, \
1601 "0 : Normal. "\
1602 " VM chooses priorities that are appropriate for normal "\
1603 " applications. "\
1604 " On Windows applications are allowed to use higher native "\
1605 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1606 " not use the highest possible native priority, "\
1607 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1608 " system threads. On Linux thread priorities are ignored "\
1609 " because the OS does not support static priority in "\
1610 " SCHED_OTHER scheduling class which is the only choice for "\
1611 " non-root, non-realtime applications. "\
1612 "1 : Aggressive. "\
1613 " Java thread priorities map over to the entire range of "\
1614 " native thread priorities. Higher Java thread priorities map "\
1615 " to higher native thread priorities. This policy should be "\
1616 " used with care, as sometimes it can cause performance "\
1617 " degradation in the application and/or the entire system. On "\
1618 " Linux/BSD/macOS this policy requires root privilege or an "\
1619 " extended capability.") \
1620 range(0, 1) \
1621 \
1622 product(bool, ThreadPriorityVerbose, false, \
1623 "Print priority changes") \
1624 \
1625 product(int, CompilerThreadPriority, -1, \
1626 "The native priority at which compiler threads should run " \
1627 "(-1 means no change)") \
1628 range(min_jint, max_jint) \
1629 \
1630 product(int, VMThreadPriority, -1, \
1631 "The native priority at which the VM thread should run " \
1632 "(-1 means no change)") \
1633 range(-1, 127) \
1634 \
1635 product(int, JavaPriority1_To_OSPriority, -1, \
1636 "Map Java priorities to OS priorities") \
1637 range(-1, 127) \
1638 \
1639 product(int, JavaPriority2_To_OSPriority, -1, \
1640 "Map Java priorities to OS priorities") \
1641 range(-1, 127) \
1642 \
1643 product(int, JavaPriority3_To_OSPriority, -1, \
1644 "Map Java priorities to OS priorities") \
1645 range(-1, 127) \
1646 \
1647 product(int, JavaPriority4_To_OSPriority, -1, \
1648 "Map Java priorities to OS priorities") \
1649 range(-1, 127) \
1650 \
1651 product(int, JavaPriority5_To_OSPriority, -1, \
1652 "Map Java priorities to OS priorities") \
1653 range(-1, 127) \
1654 \
1655 product(int, JavaPriority6_To_OSPriority, -1, \
1656 "Map Java priorities to OS priorities") \
1657 range(-1, 127) \
1658 \
1659 product(int, JavaPriority7_To_OSPriority, -1, \
1660 "Map Java priorities to OS priorities") \
1661 range(-1, 127) \
1662 \
1663 product(int, JavaPriority8_To_OSPriority, -1, \
1664 "Map Java priorities to OS priorities") \
1665 range(-1, 127) \
1666 \
1667 product(int, JavaPriority9_To_OSPriority, -1, \
1668 "Map Java priorities to OS priorities") \
1669 range(-1, 127) \
1670 \
1671 product(int, JavaPriority10_To_OSPriority,-1, \
1672 "Map Java priorities to OS priorities") \
1673 range(-1, 127) \
1674 \
1675 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1676 "Java thread priority 10 maps to critical scheduling priority") \
1677 \
1678 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1679 "Compiler thread(s) run at critical scheduling priority") \
1680 \
1681 develop(intx, NewCodeParameter, 0, \
1682 "Testing Only: Create a dedicated integer parameter before " \
1683 "putback") \
1684 \
1685 /* new oopmap storage allocation */ \
1686 develop(intx, MinOopMapAllocation, 8, \
1687 "Minimum number of OopMap entries in an OopMapSet") \
1688 \
1689 /* recompilation */ \
1690 product_pd(intx, CompileThreshold, \
1691 "number of interpreted method invocations before (re-)compiling") \
1692 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1693 \
1694 product_pd(bool, TieredCompilation, \
1695 "Enable tiered compilation") \
1696 \
1697 /* Properties for Java libraries */ \
1698 \
1699 product(uint64_t, MaxDirectMemorySize, 0, \
1700 "Maximum total size of NIO direct-buffer allocations. " \
1701 "Ignored if not explicitly set.") \
1702 range(0, max_jlong) \
1703 \
1704 /* Flags used for temporary code during development */ \
1705 \
1706 product(bool, UseNewCode, false, DIAGNOSTIC, \
1707 "Testing Only: Use the new version while testing") \
1708 \
1709 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1710 "Testing Only: Use the new version while testing") \
1711 \
1712 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1713 "Testing Only: Use the new version while testing") \
1714 \
1715 notproduct(bool, UseDebuggerErgo, false, \
1716 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1717 "Turns on the other UseDebuggerErgo* flags") \
1718 \
1719 notproduct(bool, UseDebuggerErgo1, false, \
1720 "Debugging Only: Enable workarounds for debugger induced " \
1721 "os::processor_id() >= os::processor_count() problems") \
1722 \
1723 notproduct(bool, UseDebuggerErgo2, false, \
1724 "Debugging Only: Limit the number of spawned JVM threads") \
1725 \
1726 notproduct(bool, EnableJVMTIStackDepthAsserts, true, \
1727 "Enable JVMTI asserts related to stack depth checks") \
1728 \
1729 /* flags for performance data collection */ \
1730 \
1731 product(bool, UsePerfData, true, \
1732 "Flag to disable jvmstat instrumentation for performance testing "\
1733 "and problem isolation purposes") \
1734 \
1735 product(bool, PerfDataSaveToFile, false, \
1736 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1737 \
1738 product(ccstr, PerfDataSaveFile, NULL, \
1739 "Save PerfData memory to the specified absolute pathname. " \
1740 "The string %p in the file name (if present) " \
1741 "will be replaced by pid") \
1742 \
1743 product(intx, PerfDataSamplingInterval, 50, \
1744 "Data sampling interval (in milliseconds)") \
1745 range(PeriodicTask::min_interval, max_jint) \
1746 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1747 \
1748 product(bool, PerfDisableSharedMem, false, \
1749 "Store performance data in standard memory") \
1750 \
1751 product(int, PerfDataMemorySize, 32*K, \
1752 "Size of performance data memory region. Will be rounded " \
1753 "up to a multiple of the native os page size.") \
1754 range(128, 32*64*K) \
1755 \
1756 product(int, PerfMaxStringConstLength, 1024, \
1757 "Maximum PerfStringConstant string length before truncation") \
1758 range(32, 32*K) \
1759 \
1760 product(bool, PerfAllowAtExitRegistration, false, \
1761 "Allow registration of atexit() methods") \
1762 \
1763 product(bool, PerfBypassFileSystemCheck, false, \
1764 "Bypass Win32 file system criteria checks (Windows Only)") \
1765 \
1766 product(int, UnguardOnExecutionViolation, 0, \
1767 "Unguard page and retry on no-execute fault (Win32 only) " \
1768 "0=off, 1=conservative, 2=aggressive") \
1769 range(0, 2) \
1770 \
1771 /* Serviceability Support */ \
1772 \
1773 product(bool, ManagementServer, false, \
1774 "Create JMX Management Server") \
1775 \
1776 product(bool, DisableAttachMechanism, false, \
1777 "Disable mechanism that allows tools to attach to this VM") \
1778 \
1779 product(bool, StartAttachListener, false, \
1780 "Always start Attach Listener at VM startup") \
1781 \
1782 product(bool, EnableDynamicAgentLoading, true, \
1783 "Allow tools to load agents with the attach mechanism") \
1784 \
1785 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1786 "Print java.util.concurrent locks in thread dump") \
1787 \
1788 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1789 "Print generated stub code for method handles") \
1790 \
1791 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1792 "perform extra checks when constructing method handles") \
1793 \
1794 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1795 "show method handle implementation frames (usually hidden)") \
1796 \
1797 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1798 "show virtual threads' carrier frames in exceptions") \
1799 \
1800 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1801 "trust final non-static declarations for constant folding") \
1802 \
1803 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1804 "Optimize loads from stable fields (marked w/ @Stable)") \
1805 \
1806 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1807 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1808 "resolved before the bootstrap method is called; 1: when a BSM " \
1809 "that may accept a BootstrapCallInfo is detected, use that API " \
1810 "to pass BSM arguments, which allows the BSM to delay their " \
1811 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1812 "via that API, instead of with the eagerly-resolved array.") \
1813 \
1814 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1815 "Causes the VM to pause at startup time and wait for the pause " \
1816 "file to be removed (default: ./vm.paused.<pid>)") \
1817 \
1818 product(ccstr, PauseAtStartupFile, NULL, DIAGNOSTIC, \
1819 "The file to create and for whose removal to await when pausing " \
1820 "at startup. (default: ./vm.paused.<pid>)") \
1821 \
1822 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1823 "Pause and wait for keypress on exit if a debugger is attached") \
1824 \
1825 product(bool, ExtendedDTraceProbes, false, \
1826 "(Deprecated) Enable performance-impacting dtrace probes. " \
1827 "Use the combination of -XX:+DTraceMethodProbes, " \
1828 "-XX:+DTraceAllocProbes and -XX:+DTraceMonitorProbes instead.") \
1829 \
1830 product(bool, DTraceMethodProbes, false, \
1831 "Enable dtrace tool probes for method-entry and method-exit") \
1832 \
1833 product(bool, DTraceAllocProbes, false, \
1834 "Enable dtrace tool probes for object allocation") \
1835 \
1836 product(bool, DTraceMonitorProbes, false, \
1837 "Enable dtrace tool probes for monitor events") \
1838 \
1839 product(bool, RelaxAccessControlCheck, false, \
1840 "Relax the access control checks in the verifier") \
1841 \
1842 product(uintx, StringTableSize, defaultStringTableSize, \
1843 "Number of buckets in the interned String table " \
1844 "(will be rounded to nearest higher power of 2)") \
1845 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1846 \
1847 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1848 "Number of buckets in the JVM internal Symbol table") \
1849 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1850 \
1851 product(bool, UseStringDeduplication, false, \
1852 "Use string deduplication") \
1853 \
1854 product(uint, StringDeduplicationAgeThreshold, 3, \
1855 "A string must reach this age (or be promoted to an old region) " \
1856 "to be considered for deduplication") \
1857 range(1, markWord::max_age) \
1858 \
1859 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1860 "Approximate initial number of buckets in the table") \
1861 range(1, 1 * G) \
1862 \
1863 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1864 "Entries per bucket above which the table should be expanded") \
1865 range(0.1, 1000.0) \
1866 \
1867 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1868 "Entries per bucket below which the table should be shrunk") \
1869 range(0.01, 100.0) \
1870 \
1871 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1872 "Desired entries per bucket when resizing the table") \
1873 range(0.01, 1000.0) \
1874 \
1875 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1876 "Minimum number of dead table entries for cleaning the table") \
1877 \
1878 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1879 "Minimum percentage of dead table entries for cleaning the table") \
1880 range(1, 100) \
1881 \
1882 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1883 "Force more frequent table resizing") \
1884 \
1885 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1886 "Seed for the table hashing function; 0 requests computed seed") \
1887 \
1888 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1889 "Enable internal testing APIs") \
1890 \
1891 product(size_t, ArrayAllocatorMallocLimit, (size_t)-1, EXPERIMENTAL, \
1892 "Allocation less than this value will be allocated " \
1893 "using malloc. Larger allocations will use mmap.") \
1894 \
1895 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1896 "Accesses to all variables should always be atomic") \
1897 \
1898 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1899 "Use unaligned memory accesses in Unsafe") \
1900 \
1901 product_pd(bool, PreserveFramePointer, \
1902 "Use the FP register for holding the frame pointer " \
1903 "and not as a general purpose register.") \
1904 \
1905 product(size_t, AsyncLogBufferSize, 2*M, \
1906 "Memory budget (in bytes) for the buffer of Asynchronous " \
1907 "Logging (-Xlog:async).") \
1908 range(100*K, 50*M) \
1909 \
1910 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1911 "When a class C is loaded, check that " \
1912 "(1) all intrinsics defined by the VM for class C are present "\
1913 "in the loaded class file and are marked with the " \
1914 "@IntrinsicCandidate annotation, that " \
1915 "(2) there is an intrinsic registered for all loaded methods " \
1916 "that are annotated with the @IntrinsicCandidate annotation, " \
1917 "and that " \
1918 "(3) no orphan methods exist for class C (i.e., methods for " \
1919 "which the VM declares an intrinsic but that are not declared "\
1920 "in the loaded class C. " \
1921 "Check (3) is available only in debug builds.") \
1922 \
1923 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1924 "Threshold small size (in bytes) for clearing arrays. " \
1925 "Anything this size or smaller may get converted to discrete " \
1926 "scalar stores.") \
1927 range(0, max_intx) \
1928 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1929 \
1930 product(ccstr, AllocateHeapAt, NULL, \
1931 "Path to the directory where a temporary file will be created " \
1932 "to use as the backing store for Java Heap.") \
1933 \
1934 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1935 "Enable VM continuations support") \
1936 \
1937 develop(bool, LoomDeoptAfterThaw, false, \
1938 "Deopt stack after thaw") \
1939 \
1940 develop(bool, LoomVerifyAfterThaw, false, \
1941 "Verify stack after thaw") \
1942 \
1943 develop(bool, VerifyContinuations, true, \
1944 "Verify continuation consistency") \
1945 \
1946 develop(bool, UseContinuationFastPath, true, \
1947 "Use fast-path frame walking in continuations") \
1948 \
1949 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1950 "Run periodic metaspace verifications (0 - none, " \
1951 "1 - always, >1 every nth interval)") \
1952 \
1953 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1954 "On internal errors, include registers in error report.") \
1955 \
1956 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1957 "leverage profiling for table/lookup switch") \
1958 \
1959 develop(bool, TraceMemoryWriteback, false, \
1960 "Trace memory writeback operations") \
1961 \
1962 JFR_ONLY(product(bool, FlightRecorder, false, \
1963 "(Deprecated) Enable Flight Recorder")) \
1964 \
1965 JFR_ONLY(product(ccstr, FlightRecorderOptions, NULL, \
1966 "Flight Recorder options")) \
1967 \
1968 JFR_ONLY(product(ccstr, StartFlightRecording, NULL, \
1969 "Start flight recording with options")) \
1970 \
1971 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1972 "Use platform unstable time where supported for timestamps only") \
1973 \
1974 product(bool, UseEmptySlotsInSupers, true, \
1975 "Allow allocating fields in empty slots of super-classes") \
1976 \
1977 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1978 "Make nmethod barriers deoptimise a lot.") \
1979 \
1980 develop(bool, VerifyCrossModifyFence, \
1981 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1982 "Mark all threads after a safepoint, and clear on a modify " \
1983 "fence. Add cleanliness checks.") \
1984 \
1985 develop(bool, TraceOptimizedUpcallStubs, false, \
1986 "Trace optimized upcall stub generation") \
1987
1988 // end of RUNTIME_FLAGS
1989
1990 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
1991 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
1992 DECLARE_FLAGS(RUNTIME_FLAGS)
1993 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
1994
1995 #endif // SHARE_RUNTIME_GLOBALS_HPP