1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_RUNTIME_GLOBALS_HPP
26 #define SHARE_RUNTIME_GLOBALS_HPP
27
28 #include "compiler/compiler_globals_pd.hpp"
29 #include "runtime/globals_shared.hpp"
30 #include "utilities/align.hpp"
31 #include "utilities/globalDefinitions.hpp"
32 #include "utilities/macros.hpp"
33 #include CPU_HEADER(globals)
34 #include OS_HEADER(globals)
35 #include OS_CPU_HEADER(globals)
36
37 // develop flags are settable / visible only during development and are constant in the PRODUCT version
38 // product flags are always settable / visible
39 // develop_pd/product_pd flags are the same as develop/product, except that their default values
40 // are specified in platform-dependent header files.
41
42 // Flags must be declared with the following number of parameters:
43 // non-pd flags:
44 // (type, name, default_value, doc), or
45 // (type, name, default_value, extra_attrs, doc)
46 // pd flags:
47 // (type, name, doc), or
48 // (type, name, extra_attrs, doc)
49
50 // A flag must be declared with one of the following types:
51 // bool, int, uint, intx, uintx, size_t, ccstr, ccstrlist, double, or uint64_t.
52 // The type "ccstr" and "ccstrlist" are an alias for "const char*" and is used
53 // only in this file, because the macrology requires single-token type names.
54
55 // The optional extra_attrs parameter may have one of the following values:
56 // DIAGNOSTIC, EXPERIMENTAL, or MANAGEABLE. Currently extra_attrs can be used
57 // only with product/product_pd flags.
58 //
59 // DIAGNOSTIC options are not meant for VM tuning or for product modes.
60 // They are to be used for VM quality assurance or field diagnosis
61 // of VM bugs. They are hidden so that users will not be encouraged to
62 // try them as if they were VM ordinary execution options. However, they
63 // are available in the product version of the VM. Under instruction
64 // from support engineers, VM customers can turn them on to collect
65 // diagnostic information about VM problems. To use a VM diagnostic
66 // option, you must first specify +UnlockDiagnosticVMOptions.
67 // (This master switch also affects the behavior of -Xprintflags.)
68 //
69 // EXPERIMENTAL flags are in support of features that may not be
70 // an officially supported part of a product, but may be available
71 // for experimenting with. They could, for example, be performance
72 // features that may not have undergone full or rigorous QA, but which may
73 // help performance in some cases and released for experimentation
74 // by the community of users and developers. This flag also allows one to
75 // be able to build a fully supported product that nonetheless also
76 // ships with some unsupported, lightly tested, experimental features.
77 // Refer to the documentation of any products using this code for details
78 // on support and fitness for production.
79 // Like the UnlockDiagnosticVMOptions flag above, there is a corresponding
80 // UnlockExperimentalVMOptions flag, which allows the control and
81 // modification of the experimental flags.
82 //
83 // Nota bene: neither diagnostic nor experimental options should be used casually,
84 // Refer to the documentation of any products using this code for details.
85 //
86 // MANAGEABLE flags are writeable external product flags.
87 // They are dynamically writeable through the JDK management interface
88 // (com.sun.management.HotSpotDiagnosticMXBean API) and also through JConsole.
89 // These flags are external exported interface (see CSR). The list of
90 // manageable flags can be queried programmatically through the management
91 // interface.
92 //
93 // A flag can be made as "manageable" only if
94 // - the flag is defined in a CSR request as an external exported interface.
95 // - the VM implementation supports dynamic setting of the flag.
96 // This implies that the VM must *always* query the flag variable
97 // and not reuse state related to the flag state at any given time.
98 // - you want the flag to be queried programmatically by the customers.
99 //
100
101 //
102 // range is a macro that will expand to min and max arguments for range
103 // checking code if provided - see jvmFlagLimit.hpp
104 //
105 // constraint is a macro that will expand to custom function call
106 // for constraint checking if provided - see jvmFlagLimit.hpp
107
108 // Default and minimum StringTable and SymbolTable size values
109 // Must be powers of 2
110 const size_t defaultStringTableSize = NOT_LP64(1024) LP64_ONLY(65536);
111 const size_t minimumStringTableSize = 128;
112 const size_t defaultSymbolTableSize = 32768; // 2^15
113 const size_t minimumSymbolTableSize = 1024;
114
115 #ifdef _LP64
116 #define LP64_RUNTIME_FLAGS(develop, \
117 develop_pd, \
118 product, \
119 product_pd, \
120 range, \
121 constraint) \
122 \
123 product(bool, UseCompressedOops, false, \
124 "Use 32-bit object references in 64-bit VM. " \
125 "lp64_product means flag is always constant in 32 bit VM") \
126 \
127 product(bool, UseCompressedClassPointers, true, \
128 "Use 32-bit class pointers in 64-bit VM. " \
129 "lp64_product means flag is always constant in 32 bit VM") \
130 \
131 product(int, ObjectAlignmentInBytes, 8, \
132 "Default object alignment in bytes, 8 is minimum") \
133 range(8, 256) \
134 constraint(ObjectAlignmentInBytesConstraintFunc, AtParse)
135
136 #else
137 // !_LP64
138
139 #define LP64_RUNTIME_FLAGS(develop, \
140 develop_pd, \
141 product, \
142 product_pd, \
143 range, \
144 constraint)
145 const bool UseCompressedOops = false;
146 const bool UseCompressedClassPointers = false;
147 const int ObjectAlignmentInBytes = 8;
148
149 #endif // _LP64
150
151 #define RUNTIME_FLAGS(develop, \
152 develop_pd, \
153 product, \
154 product_pd, \
155 range, \
156 constraint) \
157 \
158 develop(bool, CheckCompressedOops, true, \
159 "Generate checks in encoding/decoding code in debug VM") \
160 \
161 product(uintx, HeapSearchSteps, 3 PPC64_ONLY(+17), \
162 "Heap allocation steps through preferred address regions to find" \
163 " where it can allocate the heap. Number of steps to take per " \
164 "region.") \
165 range(1, max_uintx) \
166 \
167 product(uint, HandshakeTimeout, 0, DIAGNOSTIC, \
168 "If nonzero set a timeout in milliseconds for handshakes") \
169 \
170 product(bool, AlwaysSafeConstructors, false, EXPERIMENTAL, \
171 "Force safe construction, as if all fields are final.") \
172 \
173 product(bool, UnlockDiagnosticVMOptions, trueInDebug, DIAGNOSTIC, \
174 "Enable normal processing of flags relating to field diagnostics")\
175 \
176 product(bool, UnlockExperimentalVMOptions, false, EXPERIMENTAL, \
177 "Enable normal processing of flags relating to experimental " \
178 "features") \
179 \
180 product(bool, JavaMonitorsInStackTrace, true, \
181 "Print information about Java monitor locks when the stacks are " \
182 "dumped") \
183 \
184 product_pd(bool, UseLargePages, \
185 "Use large page memory") \
186 \
187 product_pd(bool, UseLargePagesIndividualAllocation, \
188 "Allocate large pages individually for better affinity") \
189 \
190 develop(bool, LargePagesIndividualAllocationInjectError, false, \
191 "Fail large pages individual allocation") \
192 \
193 product(bool, UseNUMA, false, \
194 "Use NUMA if available") \
195 \
196 product(bool, UseNUMAInterleaving, false, \
197 "Interleave memory across NUMA nodes if available") \
198 \
199 product(size_t, NUMAInterleaveGranularity, 2*M, \
200 "Granularity to use for NUMA interleaving on Windows OS") \
201 constraint(NUMAInterleaveGranularityConstraintFunc, AtParse) \
202 \
203 product(uintx, NUMAChunkResizeWeight, 20, \
204 "Percentage (0-100) used to weight the current sample when " \
205 "computing exponentially decaying average for " \
206 "AdaptiveNUMAChunkSizing") \
207 range(0, 100) \
208 \
209 product(size_t, NUMASpaceResizeRate, 1*G, \
210 "Do not reallocate more than this amount per collection") \
211 range(0, max_uintx) \
212 \
213 product(bool, UseAdaptiveNUMAChunkSizing, true, \
214 "Enable adaptive chunk sizing for NUMA") \
215 \
216 product(bool, NUMAStats, false, \
217 "Print NUMA stats in detailed heap information") \
218 \
219 product(bool, UseAES, false, \
220 "Control whether AES instructions are used when available") \
221 \
222 product(bool, UseFMA, false, \
223 "Control whether FMA instructions are used when available") \
224 \
225 product(bool, UseSHA, false, \
226 "Control whether SHA instructions are used when available") \
227 \
228 product(bool, UseGHASHIntrinsics, false, DIAGNOSTIC, \
229 "Use intrinsics for GHASH versions of crypto") \
230 \
231 product(bool, UseBASE64Intrinsics, false, \
232 "Use intrinsics for java.util.Base64") \
233 \
234 product(bool, UsePoly1305Intrinsics, false, DIAGNOSTIC, \
235 "Use intrinsics for sun.security.util.math.intpoly") \
236 product(bool, UseIntPolyIntrinsics, false, DIAGNOSTIC, \
237 "Use intrinsics for sun.security.util.math.intpoly.MontgomeryIntegerPolynomialP256") \
238 \
239 product(size_t, LargePageSizeInBytes, 0, \
240 "Maximum large page size used (0 will use the default large " \
241 "page size for the environment as the maximum)") \
242 range(0, max_uintx) \
243 \
244 product(size_t, LargePageHeapSizeThreshold, 128*M, \
245 "Use large pages if maximum heap is at least this big") \
246 range(0, max_uintx) \
247 \
248 product(bool, ForceTimeHighResolution, false, \
249 "Using high time resolution (for Win32 only)") \
250 \
251 develop(bool, TracePcPatching, false, \
252 "Trace usage of frame::patch_pc") \
253 \
254 develop(bool, TraceRelocator, false, \
255 "Trace the bytecode relocator") \
256 \
257 \
258 product(bool, SafepointALot, false, DIAGNOSTIC, \
259 "Generate a lot of safepoints. This works with " \
260 "GuaranteedSafepointInterval") \
261 \
262 product(bool, HandshakeALot, false, DIAGNOSTIC, \
263 "Generate a lot of handshakes. This works with " \
264 "GuaranteedSafepointInterval") \
265 \
266 product_pd(bool, BackgroundCompilation, \
267 "A thread requesting compilation is not blocked during " \
268 "compilation") \
269 \
270 product(bool, MethodFlushing, true, \
271 "Reclamation of compiled methods") \
272 \
273 develop(bool, VerifyStack, false, \
274 "Verify stack of each thread when it is entering a runtime call") \
275 \
276 product(bool, ForceUnreachable, false, DIAGNOSTIC, \
277 "Make all non code cache addresses to be unreachable by " \
278 "forcing use of 64bit literal fixups") \
279 \
280 develop(bool, TraceDerivedPointers, false, \
281 "Trace traversal of derived pointers on stack") \
282 \
283 develop(bool, TraceCodeBlobStacks, false, \
284 "Trace stack-walk of codeblobs") \
285 \
286 develop(bool, PrintRewrites, false, \
287 "Print methods that are being rewritten") \
288 \
289 product(bool, UseInlineCaches, true, \
290 "Use Inline Caches for virtual calls ") \
291 \
292 product(size_t, InlineCacheBufferSize, 10*K, EXPERIMENTAL, \
293 "InlineCacheBuffer size") \
294 \
295 product(bool, InlineArrayCopy, true, DIAGNOSTIC, \
296 "Inline arraycopy native that is known to be part of " \
297 "base library DLL") \
298 \
299 product(bool, InlineObjectHash, true, DIAGNOSTIC, \
300 "Inline Object::hashCode() native that is known to be part " \
301 "of base library DLL") \
302 \
303 product(bool, InlineNatives, true, DIAGNOSTIC, \
304 "Inline natives that are known to be part of base library DLL") \
305 \
306 product(bool, InlineMathNatives, true, DIAGNOSTIC, \
307 "Inline SinD, CosD, etc.") \
308 \
309 product(bool, InlineClassNatives, true, DIAGNOSTIC, \
310 "Inline Class.isInstance, etc") \
311 \
312 product(bool, InlineThreadNatives, true, DIAGNOSTIC, \
313 "Inline Thread.currentThread, etc") \
314 \
315 product(bool, InlineUnsafeOps, true, DIAGNOSTIC, \
316 "Inline memory ops (native methods) from Unsafe") \
317 \
318 product(bool, UseAESIntrinsics, false, DIAGNOSTIC, \
319 "Use intrinsics for AES versions of crypto") \
320 \
321 product(bool, UseAESCTRIntrinsics, false, DIAGNOSTIC, \
322 "Use intrinsics for the paralleled version of AES/CTR crypto") \
323 \
324 product(bool, UseChaCha20Intrinsics, false, DIAGNOSTIC, \
325 "Use intrinsics for the vectorized version of ChaCha20") \
326 \
327 product(bool, UseMD5Intrinsics, false, DIAGNOSTIC, \
328 "Use intrinsics for MD5 crypto hash function") \
329 \
330 product(bool, UseSHA1Intrinsics, false, DIAGNOSTIC, \
331 "Use intrinsics for SHA-1 crypto hash function. " \
332 "Requires that UseSHA is enabled.") \
333 \
334 product(bool, UseSHA256Intrinsics, false, DIAGNOSTIC, \
335 "Use intrinsics for SHA-224 and SHA-256 crypto hash functions. " \
336 "Requires that UseSHA is enabled.") \
337 \
338 product(bool, UseSHA512Intrinsics, false, DIAGNOSTIC, \
339 "Use intrinsics for SHA-384 and SHA-512 crypto hash functions. " \
340 "Requires that UseSHA is enabled.") \
341 \
342 product(bool, UseSHA3Intrinsics, false, DIAGNOSTIC, \
343 "Use intrinsics for SHA3 crypto hash function. " \
344 "Requires that UseSHA is enabled.") \
345 \
346 product(bool, UseCRC32Intrinsics, false, DIAGNOSTIC, \
347 "use intrinsics for java.util.zip.CRC32") \
348 \
349 product(bool, UseCRC32CIntrinsics, false, DIAGNOSTIC, \
350 "use intrinsics for java.util.zip.CRC32C") \
351 \
352 product(bool, UseAdler32Intrinsics, false, DIAGNOSTIC, \
353 "use intrinsics for java.util.zip.Adler32") \
354 \
355 product(bool, UseVectorizedMismatchIntrinsic, false, DIAGNOSTIC, \
356 "Enables intrinsification of ArraysSupport.vectorizedMismatch()") \
357 \
358 product(bool, UseVectorizedHashCodeIntrinsic, false, DIAGNOSTIC, \
359 "Enables intrinsification of ArraysSupport.vectorizedHashCode()") \
360 \
361 product(bool, UseCopySignIntrinsic, false, DIAGNOSTIC, \
362 "Enables intrinsification of Math.copySign") \
363 \
364 product(bool, UseSignumIntrinsic, false, DIAGNOSTIC, \
365 "Enables intrinsification of Math.signum") \
366 \
367 product_pd(bool, DelayCompilerStubsGeneration, DIAGNOSTIC, \
368 "Use Compiler thread for compiler's stubs generation") \
369 \
370 product(ccstrlist, DisableIntrinsic, "", DIAGNOSTIC, \
371 "do not expand intrinsics whose (internal) names appear here") \
372 constraint(DisableIntrinsicConstraintFunc,AfterErgo) \
373 \
374 product(ccstrlist, ControlIntrinsic, "", DIAGNOSTIC, \
375 "Control intrinsics using a list of +/- (internal) names, " \
376 "separated by commas") \
377 constraint(ControlIntrinsicConstraintFunc,AfterErgo) \
378 \
379 develop(bool, TraceCallFixup, false, \
380 "Trace all call fixups") \
381 \
382 develop(bool, DeoptimizeALot, false, \
383 "Deoptimize at every exit from the runtime system") \
384 \
385 develop(ccstrlist, DeoptimizeOnlyAt, "", \
386 "A comma separated list of bcis to deoptimize at") \
387 \
388 develop(bool, DeoptimizeRandom, false, \
389 "Deoptimize random frames on random exit from the runtime system")\
390 \
391 develop(bool, ZombieALot, false, \
392 "Create non-entrant nmethods at exit from the runtime system") \
393 \
394 develop(bool, WalkStackALot, false, \
395 "Trace stack (no print) at every exit from the runtime system") \
396 \
397 develop(bool, DeoptimizeObjectsALot, false, \
398 "For testing purposes concurrent threads revert optimizations " \
399 "based on escape analysis at intervals given with " \
400 "DeoptimizeObjectsALotInterval=n. The thread count is given " \
401 "with DeoptimizeObjectsALotThreadCountSingle and " \
402 "DeoptimizeObjectsALotThreadCountAll.") \
403 \
404 develop(uint64_t, DeoptimizeObjectsALotInterval, 5, \
405 "Interval for DeoptimizeObjectsALot.") \
406 range(0, max_jlong) \
407 \
408 develop(int, DeoptimizeObjectsALotThreadCountSingle, 1, \
409 "The number of threads that revert optimizations based on " \
410 "escape analysis for a single thread if DeoptimizeObjectsALot " \
411 "is enabled. The target thread is selected round robin." ) \
412 range(0, max_jint) \
413 \
414 develop(int, DeoptimizeObjectsALotThreadCountAll, 1, \
415 "The number of threads that revert optimizations based on " \
416 "escape analysis for all threads if DeoptimizeObjectsALot " \
417 "is enabled." ) \
418 range(0, max_jint) \
419 \
420 develop(bool, VerifyLastFrame, false, \
421 "Verify oops on last frame on entry to VM") \
422 \
423 product(bool, SafepointTimeout, false, \
424 "Time out and warn or fail after SafepointTimeoutDelay " \
425 "milliseconds if failed to reach safepoint") \
426 \
427 product(bool, AbortVMOnSafepointTimeout, false, DIAGNOSTIC, \
428 "Abort upon failure to reach safepoint (see SafepointTimeout)") \
429 \
430 product(uint64_t, AbortVMOnSafepointTimeoutDelay, 0, DIAGNOSTIC, \
431 "Delay in milliseconds for option AbortVMOnSafepointTimeout") \
432 range(0, max_jlong) \
433 \
434 product(bool, AbortVMOnVMOperationTimeout, false, DIAGNOSTIC, \
435 "Abort upon failure to complete VM operation promptly") \
436 \
437 product(intx, AbortVMOnVMOperationTimeoutDelay, 1000, DIAGNOSTIC, \
438 "Delay in milliseconds for option AbortVMOnVMOperationTimeout") \
439 range(0, max_intx) \
440 \
441 product(bool, MaxFDLimit, true, \
442 "Bump the number of file descriptors to maximum (Unix only)") \
443 \
444 product(bool, LogEvents, true, DIAGNOSTIC, \
445 "Enable the various ring buffer event logs") \
446 \
447 product(int, LogEventsBufferEntries, 20, DIAGNOSTIC, \
448 "Number of ring buffer event logs") \
449 range(1, NOT_LP64(1*K) LP64_ONLY(1*M)) \
450 \
451 product(bool, BytecodeVerificationRemote, true, DIAGNOSTIC, \
452 "Enable the Java bytecode verifier for remote classes") \
453 \
454 product(bool, BytecodeVerificationLocal, false, DIAGNOSTIC, \
455 "Enable the Java bytecode verifier for local classes") \
456 \
457 develop(bool, VerifyStackAtCalls, false, \
458 "Verify that the stack pointer is unchanged after calls") \
459 \
460 develop(bool, TraceJavaAssertions, false, \
461 "Trace java language assertions") \
462 \
463 develop(bool, VerifyCodeCache, false, \
464 "Verify code cache on memory allocation/deallocation") \
465 \
466 develop(bool, ZapResourceArea, trueInDebug, \
467 "Zap freed resource/arena space") \
468 \
469 develop(bool, ZapVMHandleArea, trueInDebug, \
470 "Zap freed VM handle space") \
471 \
472 develop(bool, ZapStackSegments, trueInDebug, \
473 "Zap allocated/freed stack segments") \
474 \
475 develop(bool, ZapUnusedHeapArea, trueInDebug, \
476 "Zap unused heap space") \
477 \
478 develop(bool, ZapFillerObjects, trueInDebug, \
479 "Zap filler objects") \
480 \
481 develop(bool, ZapTLAB, trueInDebug, \
482 "Zap allocated TLABs") \
483 \
484 product(bool, ExecutingUnitTests, false, \
485 "Whether the JVM is running unit tests or not") \
486 \
487 develop(uint, ErrorHandlerTest, 0, \
488 "If > 0, provokes an error after VM initialization; the value " \
489 "determines which error to provoke. See controlled_crash() " \
490 "in vmError.cpp.") \
491 range(0, 17) \
492 \
493 develop(uint, TestCrashInErrorHandler, 0, \
494 "If > 0, provokes an error inside VM error handler (a secondary " \
495 "crash). see controlled_crash() in vmError.cpp") \
496 range(0, 17) \
497 \
498 develop(bool, TestSafeFetchInErrorHandler, false , \
499 "If true, tests SafeFetch inside error handler.") \
500 \
501 develop(bool, TestUnresponsiveErrorHandler, false, \
502 "If true, simulates an unresponsive error handler.") \
503 \
504 develop(bool, Verbose, false, \
505 "Print additional debugging information from other modes") \
506 \
507 develop(bool, PrintMiscellaneous, false, \
508 "Print uncategorized debugging information (requires +Verbose)") \
509 \
510 develop(bool, WizardMode, false, \
511 "Print much more debugging information") \
512 \
513 product(bool, ShowMessageBoxOnError, false, \
514 "Keep process alive on VM fatal error") \
515 \
516 product(bool, CreateCoredumpOnCrash, true, \
517 "Create core/mini dump on VM fatal error") \
518 \
519 product(uint64_t, ErrorLogTimeout, 2 * 60, \
520 "Timeout, in seconds, to limit the time spent on writing an " \
521 "error log in case of a crash.") \
522 range(0, (uint64_t)max_jlong/1000) \
523 \
524 product(bool, ErrorLogSecondaryErrorDetails, false, DIAGNOSTIC, \
525 "If enabled, show details on secondary crashes in the error log") \
526 \
527 develop(intx, TraceDwarfLevel, 0, \
528 "Debug levels for the dwarf parser") \
529 range(0, 4) \
530 \
531 product(bool, SuppressFatalErrorMessage, false, \
532 "Report NO fatal error message (avoid deadlock)") \
533 \
534 product(ccstrlist, OnError, "", \
535 "Run user-defined commands on fatal error; see VMError.cpp " \
536 "for examples") \
537 \
538 product(ccstrlist, OnOutOfMemoryError, "", \
539 "Run user-defined commands on first java.lang.OutOfMemoryError " \
540 "thrown from JVM") \
541 \
542 product(bool, HeapDumpBeforeFullGC, false, MANAGEABLE, \
543 "Dump heap to file before any major stop-the-world GC " \
544 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
545 \
546 product(bool, HeapDumpAfterFullGC, false, MANAGEABLE, \
547 "Dump heap to file after any major stop-the-world GC " \
548 "(also see FullGCHeapDumpLimit, HeapDumpPath, HeapDumpGzipLevel)")\
549 \
550 product(uint, FullGCHeapDumpLimit, 0, MANAGEABLE, \
551 "Limit the number of heap dumps triggered by " \
552 "HeapDumpBeforeFullGC or HeapDumpAfterFullGC " \
553 "(0 means no limit)") \
554 \
555 product(bool, HeapDumpOnOutOfMemoryError, false, MANAGEABLE, \
556 "Dump heap to file when java.lang.OutOfMemoryError is thrown " \
557 "from JVM " \
558 "(also see HeapDumpPath, HeapDumpGzipLevel)") \
559 \
560 product(ccstr, HeapDumpPath, nullptr, MANAGEABLE, \
561 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
562 "or HeapDumpAfterFullGC is on, the path (filename or " \
563 "directory) of the dump file (defaults to java_pid<pid>.hprof " \
564 "in the working directory)") \
565 \
566 product(int, HeapDumpGzipLevel, 0, MANAGEABLE, \
567 "When HeapDumpOnOutOfMemoryError, HeapDumpBeforeFullGC " \
568 "or HeapDumpAfterFullGC is on, the gzip compression " \
569 "level of the dump file. 0 (the default) disables gzip " \
570 "compression. Otherwise the level must be between 1 and 9.") \
571 range(0, 9) \
572 \
573 product(ccstr, NativeMemoryTracking, DEBUG_ONLY("summary") NOT_DEBUG("off"), \
574 "Native memory tracking options") \
575 \
576 product(bool, PrintNMTStatistics, false, DIAGNOSTIC, \
577 "Print native memory tracking summary data if it is on") \
578 \
579 product(bool, LogCompilation, false, DIAGNOSTIC, \
580 "Log compilation activity in detail to LogFile") \
581 \
582 product(bool, PrintCompilation, false, \
583 "Print compilations") \
584 \
585 product(intx, RepeatCompilation, 0, DIAGNOSTIC, \
586 "Repeat compilation without installing code (number of times)") \
587 range(0, max_jint) \
588 \
589 product(bool, PrintExtendedThreadInfo, false, \
590 "Print more information in thread dump") \
591 \
592 product(intx, ScavengeRootsInCode, 2, DIAGNOSTIC, \
593 "0: do not allow scavengable oops in the code cache; " \
594 "1: allow scavenging from the code cache; " \
595 "2: emit as many constants as the compiler can see") \
596 range(0, 2) \
597 \
598 product(bool, AlwaysRestoreFPU, false, \
599 "Restore the FPU control word after every JNI call (expensive)") \
600 \
601 product(bool, PrintCompilation2, false, DIAGNOSTIC, \
602 "Print additional statistics per compilation") \
603 \
604 product(bool, PrintAdapterHandlers, false, DIAGNOSTIC, \
605 "Print code generated for i2c/c2i adapters") \
606 \
607 product(bool, VerifyAdapterCalls, trueInDebug, DIAGNOSTIC, \
608 "Verify that i2c/c2i adapters are called properly") \
609 \
610 develop(bool, VerifyAdapterSharing, false, \
611 "Verify that the code for shared adapters is the equivalent") \
612 \
613 product(bool, PrintAssembly, false, DIAGNOSTIC, \
614 "Print assembly code (using external disassembler.so)") \
615 \
616 product(ccstr, PrintAssemblyOptions, nullptr, DIAGNOSTIC, \
617 "Print options string passed to disassembler.so") \
618 \
619 develop(bool, PrintNMethodStatistics, false, \
620 "Print a summary statistic for the generated nmethods") \
621 \
622 product(bool, PrintNMethods, false, DIAGNOSTIC, \
623 "Print assembly code for nmethods when generated") \
624 \
625 product(bool, PrintNativeNMethods, false, DIAGNOSTIC, \
626 "Print assembly code for native nmethods when generated") \
627 \
628 develop(bool, PrintDebugInfo, false, \
629 "Print debug information for all nmethods when generated") \
630 \
631 develop(bool, PrintRelocations, false, \
632 "Print relocation information for all nmethods when generated") \
633 \
634 develop(bool, PrintDependencies, false, \
635 "Print dependency information for all nmethods when generated") \
636 \
637 develop(bool, PrintExceptionHandlers, false, \
638 "Print exception handler tables for all nmethods when generated") \
639 \
640 develop(bool, StressCompiledExceptionHandlers, false, \
641 "Exercise compiled exception handlers") \
642 \
643 develop(bool, InterceptOSException, false, \
644 "Start debugger when an implicit OS (e.g. null pointer) " \
645 "exception happens") \
646 \
647 product(bool, PrintCodeCache, false, \
648 "Print the code cache memory usage when exiting") \
649 \
650 develop(bool, PrintCodeCache2, false, \
651 "Print detailed usage information on the code cache when exiting")\
652 \
653 product(bool, PrintCodeCacheOnCompilation, false, \
654 "Print the code cache memory usage each time a method is " \
655 "compiled") \
656 \
657 product(bool, PrintCodeHeapAnalytics, false, DIAGNOSTIC, \
658 "Print code heap usage statistics on exit and on full condition") \
659 \
660 product(bool, PrintStubCode, false, DIAGNOSTIC, \
661 "Print generated stub code") \
662 \
663 product(bool, StackTraceInThrowable, true, \
664 "Collect backtrace in throwable when exception happens") \
665 \
666 product(bool, OmitStackTraceInFastThrow, true, \
667 "Omit backtraces for some 'hot' exceptions in optimized code") \
668 \
669 product(bool, ShowCodeDetailsInExceptionMessages, true, MANAGEABLE, \
670 "Show exception messages from RuntimeExceptions that contain " \
671 "snippets of the failing code. Disable this to improve privacy.") \
672 \
673 product(bool, PrintWarnings, true, \
674 "Print JVM warnings to output stream") \
675 \
676 develop(bool, RegisterReferences, true, \
677 "Tell whether the VM should register soft/weak/final/phantom " \
678 "references") \
679 \
680 develop(bool, PrintCodeCacheExtension, false, \
681 "Print extension of code cache") \
682 \
683 develop(bool, UsePrivilegedStack, true, \
684 "Enable the security JVM functions") \
685 \
686 product(bool, ClassUnloading, true, \
687 "Do unloading of classes") \
688 \
689 product(bool, ClassUnloadingWithConcurrentMark, true, \
690 "Do unloading of classes with a concurrent marking cycle") \
691 \
692 develop(bool, PrintSystemDictionaryAtExit, false, \
693 "Print the system dictionary at exit") \
694 \
695 develop(bool, PrintClassLoaderDataGraphAtExit, false, \
696 "Print the class loader data graph at exit") \
697 \
698 product(bool, AllowParallelDefineClass, false, \
699 "Allow parallel defineClass requests for class loaders " \
700 "registering as parallel capable") \
701 \
702 product_pd(bool, DontYieldALot, \
703 "(Deprecated) Throw away obvious excess yield calls") \
704 \
705 product(bool, DisablePrimordialThreadGuardPages, false, EXPERIMENTAL, \
706 "Disable the use of stack guard pages if the JVM is loaded " \
707 "on the primordial process thread") \
708 \
709 product(bool, DoJVMTIVirtualThreadTransitions, true, EXPERIMENTAL, \
710 "Do JVMTI virtual thread mount/unmount transitions " \
711 "(disabling this flag implies no JVMTI events are posted)") \
712 \
713 /* notice: the max range value here is max_jint, not max_intx */ \
714 /* because of overflow issue */ \
715 product(intx, AsyncDeflationInterval, 250, DIAGNOSTIC, \
716 "Async deflate idle monitors every so many milliseconds when " \
717 "MonitorUsedDeflationThreshold is exceeded (0 is off).") \
718 range(0, max_jint) \
719 \
720 /* notice: the max range value here is max_jint, not max_intx */ \
721 /* because of overflow issue */ \
722 product(intx, GuaranteedAsyncDeflationInterval, 60000, DIAGNOSTIC, \
723 "Async deflate idle monitors every so many milliseconds even " \
724 "when MonitorUsedDeflationThreshold is NOT exceeded (0 is off).") \
725 range(0, max_jint) \
726 \
727 product(size_t, AvgMonitorsPerThreadEstimate, 1024, DIAGNOSTIC, \
728 "Used to estimate a variable ceiling based on number of threads " \
729 "for use with MonitorUsedDeflationThreshold (0 is off).") \
730 range(0, max_uintx) \
731 \
732 /* notice: the max range value here is max_jint, not max_intx */ \
733 /* because of overflow issue */ \
734 product(intx, MonitorDeflationMax, 1000000, DIAGNOSTIC, \
735 "The maximum number of monitors to deflate, unlink and delete " \
736 "at one time (minimum is 1024).") \
737 range(1024, max_jint) \
738 \
739 product(intx, MonitorUnlinkBatch, 500, DIAGNOSTIC, \
740 "The maximum number of monitors to unlink in one batch. ") \
741 range(1, max_jint) \
742 \
743 product(int, MonitorUsedDeflationThreshold, 90, DIAGNOSTIC, \
744 "Percentage of used monitors before triggering deflation (0 is " \
745 "off). The check is performed on AsyncDeflationInterval or " \
746 "GuaranteedAsyncDeflationInterval, whichever is lower.") \
747 range(0, 100) \
748 \
749 product(uintx, NoAsyncDeflationProgressMax, 3, DIAGNOSTIC, \
750 "Max number of no progress async deflation attempts to tolerate " \
751 "before adjusting the in_use_list_ceiling up (0 is off).") \
752 range(0, max_uintx) \
753 \
754 product(intx, hashCode, 5, EXPERIMENTAL, \
755 "(Unstable) select hashCode generation algorithm") \
756 \
757 product(bool, ReduceSignalUsage, false, \
758 "Reduce the use of OS signals in Java and/or the VM") \
759 \
760 develop(bool, LoadLineNumberTables, true, \
761 "Tell whether the class file parser loads line number tables") \
762 \
763 develop(bool, LoadLocalVariableTables, true, \
764 "Tell whether the class file parser loads local variable tables") \
765 \
766 develop(bool, LoadLocalVariableTypeTables, true, \
767 "Tell whether the class file parser loads local variable type" \
768 "tables") \
769 \
770 product(bool, AllowUserSignalHandlers, false, \
771 "Application will install primary signal handlers for the JVM " \
772 "(Unix only)") \
773 \
774 product(bool, UseSignalChaining, true, \
775 "Use signal-chaining to invoke signal handlers installed " \
776 "by the application (Unix only)") \
777 \
778 product(bool, RestoreMXCSROnJNICalls, false, \
779 "Restore MXCSR when returning from JNI calls") \
780 \
781 product(bool, CheckJNICalls, false, \
782 "Verify all arguments to JNI calls") \
783 \
784 product(bool, UseFastJNIAccessors, true, \
785 "Use optimized versions of Get<Primitive>Field") \
786 \
787 product(intx, MaxJNILocalCapacity, 65536, \
788 "Maximum allowable local JNI handle capacity to " \
789 "EnsureLocalCapacity() and PushLocalFrame(), " \
790 "where <= 0 is unlimited, default: 65536") \
791 range(min_intx, max_intx) \
792 \
793 product(bool, EagerXrunInit, false, \
794 "Eagerly initialize -Xrun libraries; allows startup profiling, " \
795 "but not all -Xrun libraries may support the state of the VM " \
796 "at this time") \
797 \
798 develop(uintx, PreallocatedOutOfMemoryErrorCount, 4, \
799 "Number of OutOfMemoryErrors preallocated with backtrace") \
800 \
801 product(bool, UseXMMForArrayCopy, false, \
802 "Use SSE2 MOVQ instruction for Arraycopy") \
803 \
804 develop(bool, PrintFieldLayout, false, \
805 "Print field layout for each class") \
806 \
807 /* Need to limit the extent of the padding to reasonable size. */\
808 /* 8K is well beyond the reasonable HW cache line size, even with */\
809 /* aggressive prefetching, while still leaving the room for segregating */\
810 /* among the distinct pages. */\
811 product(int, ContendedPaddingWidth, 128, \
812 "How many bytes to pad the fields/classes marked @Contended with")\
813 range(0, 8192) \
814 constraint(ContendedPaddingWidthConstraintFunc,AfterErgo) \
815 \
816 product(bool, EnableContended, true, \
817 "Enable @Contended annotation support") \
818 \
819 product(bool, RestrictContended, true, \
820 "Restrict @Contended to trusted classes") \
821 \
822 product(int, DiagnoseSyncOnValueBasedClasses, 0, DIAGNOSTIC, \
823 "Detect and take action upon identifying synchronization on " \
824 "value based classes. Modes: " \
825 "0: off; " \
826 "1: exit with fatal error; " \
827 "2: log message to stdout. Output file can be specified with " \
828 " -Xlog:valuebasedclasses. If JFR is running it will " \
829 " also generate JFR events.") \
830 range(0, 2) \
831 \
832 product(bool, ExitOnOutOfMemoryError, false, \
833 "JVM exits on the first occurrence of an out-of-memory error " \
834 "thrown from JVM") \
835 \
836 product(bool, CrashOnOutOfMemoryError, false, \
837 "JVM aborts, producing an error log and core/mini dump, on the " \
838 "first occurrence of an out-of-memory error thrown from JVM") \
839 \
840 product(intx, UserThreadWaitAttemptsAtExit, 30, \
841 "The number of times to wait for user threads to stop executing " \
842 "native code during JVM exit. Each wait lasts 10 milliseconds. " \
843 "The maximum number of waits is 1000, to wait at most 10 " \
844 "seconds.") \
845 range(0, 1000) \
846 \
847 /* tracing */ \
848 \
849 develop(bool, StressRewriter, false, \
850 "Stress linktime bytecode rewriting") \
851 \
852 product(ccstr, TraceJVMTI, nullptr, \
853 "Trace flags for JVMTI functions and events") \
854 \
855 product(bool, StressLdcRewrite, false, DIAGNOSTIC, \
856 "Force ldc -> ldc_w rewrite during RedefineClasses. " \
857 "This option can change an EMCP method into an obsolete method " \
858 "and can affect tests that expect specific methods to be EMCP. " \
859 "This option should be used with caution.") \
860 \
861 product(bool, AllowRedefinitionToAddDeleteMethods, false, \
862 "(Deprecated) Allow redefinition to add and delete private " \
863 "static or final methods for compatibility with old releases") \
864 \
865 develop(bool, TraceBytecodes, false, \
866 "Trace bytecode execution") \
867 \
868 develop(bool, TraceBytecodesTruncated, false, \
869 "Truncate non control-flow bytecode when tracing bytecode") \
870 \
871 develop(bool, VerifyDependencies, trueInDebug, \
872 "Exercise and verify the compilation dependency mechanism") \
873 \
874 develop(bool, TraceNewOopMapGeneration, false, \
875 "Trace OopMapGeneration") \
876 \
877 develop(bool, TraceNewOopMapGenerationDetailed, false, \
878 "Trace OopMapGeneration: print detailed cell states") \
879 \
880 develop(bool, TimeOopMap, false, \
881 "Time calls to GenerateOopMap::compute_map() in sum") \
882 \
883 develop(bool, TimeOopMap2, false, \
884 "Time calls to GenerateOopMap::compute_map() individually") \
885 \
886 develop(bool, TraceOopMapRewrites, false, \
887 "Trace rewriting of methods during oop map generation") \
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 product(ccstr, LogClassLoadingCauseFor, nullptr, \
931 "Apply -Xlog:class+load+cause* to classes whose fully " \
932 "qualified name contains this string (\"*\" matches " \
933 "any class).") \
934 \
935 develop(bool, InjectCompilerCreationFailure, false, \
936 "Inject thread creation failures for " \
937 "UseDynamicNumberOfCompilerThreads") \
938 \
939 develop(bool, GenerateSynchronizationCode, true, \
940 "generate locking/unlocking code for synchronized methods and " \
941 "monitors") \
942 \
943 product_pd(bool, ImplicitNullChecks, DIAGNOSTIC, \
944 "Generate code for implicit null checks") \
945 \
946 product_pd(bool, TrapBasedNullChecks, \
947 "Generate code for null checks that uses a cmp and trap " \
948 "instruction raising SIGTRAP. This is only used if an access to" \
949 "null (+offset) will not raise a SIGSEGV, i.e.," \
950 "ImplicitNullChecks don't work (PPC64).") \
951 \
952 product(bool, EnableThreadSMRStatistics, trueInDebug, DIAGNOSTIC, \
953 "Enable Thread SMR Statistics") \
954 \
955 product(bool, Inline, true, \
956 "Enable inlining") \
957 \
958 product(bool, ClipInlining, true, \
959 "Clip inlining if aggregate method exceeds DesiredMethodLimit") \
960 \
961 develop(bool, UseCHA, true, \
962 "Enable CHA") \
963 \
964 product(bool, UseTypeProfile, true, \
965 "Check interpreter profile for historically monomorphic calls") \
966 \
967 product(bool, PrintInlining, false, DIAGNOSTIC, \
968 "Print inlining optimizations") \
969 \
970 product(bool, UsePopCountInstruction, false, \
971 "Use population count instruction") \
972 \
973 develop(bool, TraceMethodReplacement, false, \
974 "Print when methods are replaced do to recompilation") \
975 \
976 product(intx, MinPassesBeforeFlush, 10, DIAGNOSTIC, \
977 "Minimum number of sweeper passes before an nmethod " \
978 "can be flushed") \
979 range(0, max_intx) \
980 \
981 develop(bool, StressCodeBuffers, false, \
982 "Exercise code buffer expansion and other rare state changes") \
983 \
984 product(bool, DebugNonSafepoints, trueInDebug, DIAGNOSTIC, \
985 "Generate extra debugging information for non-safepoints in " \
986 "nmethods") \
987 \
988 product(bool, PrintVMOptions, false, \
989 "Print flags that appeared on the command line") \
990 \
991 product(bool, IgnoreUnrecognizedVMOptions, false, \
992 "Ignore unrecognized VM options") \
993 \
994 product(bool, PrintCommandLineFlags, false, \
995 "Print flags specified on command line or set by ergonomics") \
996 \
997 product(bool, PrintFlagsInitial, false, \
998 "Print all VM flags before argument processing and exit VM") \
999 \
1000 product(bool, PrintFlagsFinal, false, \
1001 "Print all VM flags after argument and ergonomic processing") \
1002 \
1003 develop(bool, PrintFlagsWithComments, false, \
1004 "Print all VM flags with default values and descriptions and " \
1005 "exit") \
1006 \
1007 product(bool, PrintFlagsRanges, false, \
1008 "Print VM flags and their ranges") \
1009 \
1010 product(bool, SerializeVMOutput, true, DIAGNOSTIC, \
1011 "Use a mutex to serialize output to tty and LogFile") \
1012 \
1013 product(bool, DisplayVMOutput, true, DIAGNOSTIC, \
1014 "Display all VM output on the tty, independently of LogVMOutput") \
1015 \
1016 product(bool, LogVMOutput, false, DIAGNOSTIC, \
1017 "Save VM output to LogFile") \
1018 \
1019 product(ccstr, LogFile, nullptr, DIAGNOSTIC, \
1020 "If LogVMOutput or LogCompilation is on, save VM output to " \
1021 "this file [default: ./hotspot_pid%p.log] (%p replaced with pid)")\
1022 \
1023 product(ccstr, ErrorFile, nullptr, \
1024 "If an error occurs, save the error data to this file " \
1025 "[default: ./hs_err_pid%p.log] (%p replaced with pid)") \
1026 \
1027 product(bool, ExtensiveErrorReports, \
1028 PRODUCT_ONLY(false) NOT_PRODUCT(true), \
1029 "Error reports are more extensive.") \
1030 \
1031 product(bool, DisplayVMOutputToStderr, false, \
1032 "If DisplayVMOutput is true, display all VM output to stderr") \
1033 \
1034 product(bool, DisplayVMOutputToStdout, false, \
1035 "If DisplayVMOutput is true, display all VM output to stdout") \
1036 \
1037 product(bool, ErrorFileToStderr, false, \
1038 "If true, error data is printed to stderr instead of a file") \
1039 \
1040 product(bool, ErrorFileToStdout, false, \
1041 "If true, error data is printed to stdout instead of a file") \
1042 \
1043 develop(bool, VerifyHeavyMonitors, false, \
1044 "Checks that no stack locking happens when using " \
1045 "-XX:LockingMode=0 (LM_MONITOR)") \
1046 \
1047 product(bool, PrintStringTableStatistics, false, \
1048 "print statistics about the StringTable and SymbolTable") \
1049 \
1050 product(bool, VerifyStringTableAtExit, false, DIAGNOSTIC, \
1051 "verify StringTable contents at exit") \
1052 \
1053 develop(bool, PrintSymbolTableSizeHistogram, false, \
1054 "print histogram of the symbol table") \
1055 \
1056 product(ccstr, AbortVMOnException, nullptr, DIAGNOSTIC, \
1057 "Call fatal if this exception is thrown. Example: " \
1058 "java -XX:AbortVMOnException=java.lang.NullPointerException Foo") \
1059 \
1060 product(ccstr, AbortVMOnExceptionMessage, nullptr, DIAGNOSTIC, \
1061 "Call fatal if the exception pointed by AbortVMOnException " \
1062 "has this message") \
1063 \
1064 develop(bool, DebugVtables, false, \
1065 "add debugging code to vtable dispatch") \
1066 \
1067 product(bool, RangeCheckElimination, true, \
1068 "Eliminate range checks") \
1069 \
1070 develop_pd(bool, UncommonNullCast, \
1071 "track occurrences of null in casts; adjust compiler tactics") \
1072 \
1073 develop(bool, TypeProfileCasts, true, \
1074 "treat casts like calls for purposes of type profiling") \
1075 \
1076 develop(bool, TraceLivenessGen, false, \
1077 "Trace the generation of liveness analysis information") \
1078 \
1079 develop(bool, TraceLivenessQuery, false, \
1080 "Trace queries of liveness analysis information") \
1081 \
1082 develop(bool, CollectIndexSetStatistics, false, \
1083 "Collect information about IndexSets") \
1084 \
1085 develop(int, FastAllocateSizeLimit, 128*K, \
1086 /* Note: This value is zero mod 1<<13 for a cheap sparc set. */ \
1087 "Inline allocations larger than this in doublewords must go slow")\
1088 \
1089 product_pd(bool, CompactStrings, \
1090 "Enable Strings to use single byte chars in backing store") \
1091 \
1092 product_pd(uint, TypeProfileLevel, \
1093 "=XYZ, with Z: Type profiling of arguments at call; " \
1094 "Y: Type profiling of return value at call; " \
1095 "X: Type profiling of parameters to methods; " \
1096 "X, Y and Z in 0=off ; 1=jsr292 only; 2=all methods") \
1097 constraint(TypeProfileLevelConstraintFunc, AfterErgo) \
1098 \
1099 product(int, TypeProfileArgsLimit, 2, \
1100 "max number of call arguments to consider for type profiling") \
1101 range(0, 16) \
1102 \
1103 product(int, TypeProfileParmsLimit, 2, \
1104 "max number of incoming parameters to consider for type profiling"\
1105 ", -1 for all") \
1106 range(-1, 64) \
1107 \
1108 /* statistics */ \
1109 develop(bool, CountCompiledCalls, false, \
1110 "Count method invocations") \
1111 \
1112 develop(bool, ICMissHistogram, false, \
1113 "Produce histogram of IC misses") \
1114 \
1115 /* interpreter */ \
1116 product_pd(bool, RewriteBytecodes, \
1117 "Allow rewriting of bytecodes (bytecodes are not immutable)") \
1118 \
1119 product_pd(bool, RewriteFrequentPairs, \
1120 "Rewrite frequently used bytecode pairs into a single bytecode") \
1121 \
1122 product(bool, PrintInterpreter, false, DIAGNOSTIC, \
1123 "Print the generated interpreter code") \
1124 \
1125 product(bool, UseInterpreter, true, \
1126 "Use interpreter for non-compiled methods") \
1127 \
1128 develop(bool, UseFastSignatureHandlers, true, \
1129 "Use fast signature handlers for native calls") \
1130 \
1131 product(bool, UseLoopCounter, true, \
1132 "Increment invocation counter on backward branch") \
1133 \
1134 product_pd(bool, UseOnStackReplacement, \
1135 "Use on stack replacement, calls runtime if invoc. counter " \
1136 "overflows in loop") \
1137 \
1138 develop(bool, TraceOnStackReplacement, false, \
1139 "Trace on stack replacement") \
1140 \
1141 product_pd(bool, PreferInterpreterNativeStubs, \
1142 "Use always interpreter stubs for native methods invoked via " \
1143 "interpreter") \
1144 \
1145 develop(bool, CountBytecodes, false, \
1146 "Count number of bytecodes executed") \
1147 \
1148 develop(bool, PrintBytecodeHistogram, false, \
1149 "Print histogram of the executed bytecodes") \
1150 \
1151 develop(bool, PrintBytecodePairHistogram, false, \
1152 "Print histogram of the executed bytecode pairs") \
1153 \
1154 product(bool, PrintSignatureHandlers, false, DIAGNOSTIC, \
1155 "Print code generated for native method signature handlers") \
1156 \
1157 develop(bool, VerifyOops, false, \
1158 "Do plausibility checks for oops") \
1159 \
1160 develop(bool, CheckUnhandledOops, false, \
1161 "Check for unhandled oops in VM code") \
1162 \
1163 develop(bool, VerifyJNIFields, trueInDebug, \
1164 "Verify jfieldIDs for instance fields") \
1165 \
1166 develop(bool, VerifyFPU, false, \
1167 "Verify FPU state (check for NaN's, etc.)") \
1168 \
1169 develop(bool, VerifyActivationFrameSize, false, \
1170 "Verify that activation frame didn't become smaller than its " \
1171 "minimal size") \
1172 \
1173 develop(bool, TraceFrequencyInlining, false, \
1174 "Trace frequency based inlining") \
1175 \
1176 develop_pd(bool, InlineIntrinsics, \
1177 "Use intrinsics in Interpreter that can be statically resolved") \
1178 \
1179 product_pd(bool, ProfileInterpreter, \
1180 "Profile at the bytecode level during interpretation") \
1181 \
1182 develop_pd(bool, ProfileTraps, \
1183 "Profile deoptimization traps at the bytecode level") \
1184 \
1185 product(intx, ProfileMaturityPercentage, 20, \
1186 "number of method invocations/branches (expressed as % of " \
1187 "CompileThreshold) before using the method's profile") \
1188 range(0, 100) \
1189 \
1190 product(bool, PrintMethodData, false, DIAGNOSTIC, \
1191 "Print the results of +ProfileInterpreter at end of run") \
1192 \
1193 develop(bool, VerifyDataPointer, trueInDebug, \
1194 "Verify the method data pointer during interpreter profiling") \
1195 \
1196 develop(bool, CrashGCForDumpingJavaThread, false, \
1197 "Manually make GC thread crash then dump java stack trace; " \
1198 "Test only") \
1199 \
1200 /* compilation */ \
1201 product(bool, UseCompiler, true, \
1202 "Use Just-In-Time compilation") \
1203 \
1204 product(bool, AlwaysCompileLoopMethods, false, \
1205 "When using recompilation, never interpret methods " \
1206 "containing loops") \
1207 \
1208 product(int, AllocatePrefetchStyle, 1, \
1209 "0 = no prefetch, " \
1210 "1 = generate prefetch instructions for each allocation, " \
1211 "2 = use TLAB watermark to gate allocation prefetch, " \
1212 "3 = generate one prefetch instruction per cache line") \
1213 range(0, 3) \
1214 \
1215 product(int, AllocatePrefetchDistance, -1, \
1216 "Distance to prefetch ahead of allocation pointer. " \
1217 "-1: use system-specific value (automatically determined") \
1218 range(-1, 512) \
1219 \
1220 product(int, AllocatePrefetchLines, 3, \
1221 "Number of lines to prefetch ahead of array allocation pointer") \
1222 range(1, 64) \
1223 \
1224 product(int, AllocateInstancePrefetchLines, 1, \
1225 "Number of lines to prefetch ahead of instance allocation " \
1226 "pointer") \
1227 range(1, 64) \
1228 \
1229 product(int, AllocatePrefetchStepSize, 16, \
1230 "Step size in bytes of sequential prefetch instructions") \
1231 range(1, 512) \
1232 constraint(AllocatePrefetchStepSizeConstraintFunc,AfterMemoryInit)\
1233 \
1234 product(intx, AllocatePrefetchInstr, 0, \
1235 "Select instruction to prefetch ahead of allocation pointer") \
1236 constraint(AllocatePrefetchInstrConstraintFunc, AfterMemoryInit) \
1237 \
1238 /* deoptimization */ \
1239 product(bool, TraceDeoptimization, false, DIAGNOSTIC, \
1240 "Trace deoptimization") \
1241 \
1242 develop(bool, PrintDeoptimizationDetails, false, \
1243 "Print more information about deoptimization") \
1244 \
1245 develop(bool, DebugDeoptimization, false, \
1246 "Tracing various information while debugging deoptimization") \
1247 \
1248 product(double, SelfDestructTimer, 0.0, \
1249 "Will cause VM to terminate after a given time " \
1250 "(in fractional minutes) " \
1251 "(0.0 means off)") \
1252 range(0.0, (double)max_intx) \
1253 \
1254 product(int, MaxJavaStackTraceDepth, 1024, \
1255 "The maximum number of lines in the stack trace for Java " \
1256 "exceptions (0 means all)") \
1257 range(0, max_jint/2) \
1258 \
1259 /* notice: the max range value here is max_jint, not max_intx */ \
1260 /* because of overflow issue */ \
1261 product(intx, GuaranteedSafepointInterval, 0, DIAGNOSTIC, \
1262 "Guarantee a safepoint (at least) every so many milliseconds " \
1263 "(0 means none)") \
1264 range(0, max_jint) \
1265 \
1266 product(intx, ServiceThreadCleanupInterval, 1000, DIAGNOSTIC, \
1267 "Wake the ServiceThread to do periodic cleanup checks every so " \
1268 "many milliseconds (0 means none)") \
1269 range(0, max_jint) \
1270 \
1271 product(double, SafepointTimeoutDelay, 10000, \
1272 "Delay in milliseconds for option SafepointTimeout; " \
1273 "supports sub-millisecond resolution with fractional values.") \
1274 range(0, max_jlongDouble LP64_ONLY(/MICROUNITS)) \
1275 \
1276 product(bool, UseSystemMemoryBarrier, false, \
1277 "Try to enable system memory barrier if supported by OS") \
1278 \
1279 product(intx, NmethodSweepActivity, 4, \
1280 "Removes cold nmethods from code cache if > 0. Higher values " \
1281 "result in more aggressive sweeping") \
1282 range(0, 2000) \
1283 \
1284 develop(intx, MallocCatchPtr, -1, \
1285 "Hit breakpoint when mallocing/freeing this pointer") \
1286 \
1287 develop(int, StackPrintLimit, 100, \
1288 "number of stack frames to print in VM-level stack dump") \
1289 \
1290 product(int, ErrorLogPrintCodeLimit, 3, DIAGNOSTIC, \
1291 "max number of compiled code units to print in error log") \
1292 range(0, VMError::max_error_log_print_code) \
1293 \
1294 develop(int, MaxElementPrintSize, 256, \
1295 "maximum number of elements to print") \
1296 \
1297 develop(int, MaxStringPrintSize, 256, \
1298 "maximum number of characters to print for a java.lang.String " \
1299 "in the VM. If exceeded, an abridged version of the string is " \
1300 "printed with the middle of the string elided.") \
1301 range(2, O_BUFLEN) \
1302 \
1303 develop(intx, MaxSubklassPrintSize, 4, \
1304 "maximum number of subklasses to print when printing klass") \
1305 \
1306 develop(intx, MaxForceInlineLevel, 100, \
1307 "maximum number of nested calls that are forced for inlining " \
1308 "(using CompileCommand or marked w/ @ForceInline)") \
1309 range(0, max_jint) \
1310 \
1311 develop(intx, MethodHistogramCutoff, 100, \
1312 "The cutoff value for method invocation histogram (+CountCalls)") \
1313 \
1314 develop(intx, DeoptimizeALotInterval, 5, \
1315 "Number of exits until DeoptimizeALot kicks in") \
1316 \
1317 develop(intx, ZombieALotInterval, 5, \
1318 "Number of exits until ZombieALot kicks in") \
1319 \
1320 product(ccstr, MallocLimit, nullptr, DIAGNOSTIC, \
1321 "Limit malloc allocation size from VM. Reaching a limit will " \
1322 "trigger an action (see flag). This feature requires " \
1323 "NativeMemoryTracking=summary or NativeMemoryTracking=detail." \
1324 "Usage:" \
1325 "\"-XX:MallocLimit=<size>[:<flag>]\" sets a total limit." \
1326 "\"-XX:MallocLimit=<category>:<size>[:<flag>][,<category>:<size>[:<flag>] ...]\"" \
1327 "sets one or more category-specific limits." \
1328 "<flag> defines the action upon reaching the limit:" \
1329 "\"fatal\": end VM with a fatal error at the allocation site" \
1330 "\"oom\" : will mimic a native OOM" \
1331 "If <flag> is omitted, \"fatal\" is the default." \
1332 "Examples:\n" \
1333 "-XX:MallocLimit=2g" \
1334 "-XX:MallocLimit=2g:oom" \
1335 "-XX:MallocLimit=compiler:200m:oom,code:100m") \
1336 \
1337 product(intx, TypeProfileWidth, 2, \
1338 "Number of receiver types to record in call/cast profile") \
1339 range(0, 8) \
1340 \
1341 develop(intx, BciProfileWidth, 2, \
1342 "Number of return bci's to record in ret profile") \
1343 \
1344 product(intx, PerMethodRecompilationCutoff, 400, \
1345 "After recompiling N times, stay in the interpreter (-1=>'Inf')") \
1346 range(-1, max_intx) \
1347 \
1348 product(intx, PerBytecodeRecompilationCutoff, 200, \
1349 "Per-BCI limit on repeated recompilation (-1=>'Inf')") \
1350 range(-1, max_intx) \
1351 \
1352 product(intx, PerMethodTrapLimit, 100, \
1353 "Limit on traps (of one kind) in a method (includes inlines)") \
1354 range(0, max_jint) \
1355 \
1356 product(intx, PerMethodSpecTrapLimit, 5000, EXPERIMENTAL, \
1357 "Limit on speculative traps (of one kind) in a method " \
1358 "(includes inlines)") \
1359 range(0, max_jint) \
1360 \
1361 product(intx, PerBytecodeTrapLimit, 4, \
1362 "Limit on traps (of one kind) at a particular BCI") \
1363 range(0, max_jint) \
1364 \
1365 product(int, SpecTrapLimitExtraEntries, 3, EXPERIMENTAL, \
1366 "Extra method data trap entries for speculation") \
1367 \
1368 product(double, InlineFrequencyRatio, 0.25, DIAGNOSTIC, \
1369 "Ratio of call site execution to caller method invocation") \
1370 \
1371 product(double, MinInlineFrequencyRatio, 0.0085, DIAGNOSTIC, \
1372 "Minimum ratio of call site execution to caller method" \
1373 "invocation to be considered for inlining") \
1374 \
1375 develop(intx, InlineThrowCount, 50, \
1376 "Force inlining of interpreted methods that throw this often") \
1377 range(0, max_jint) \
1378 \
1379 develop(intx, InlineThrowMaxSize, 200, \
1380 "Force inlining of throwing methods smaller than this") \
1381 range(0, max_jint) \
1382 \
1383 product(size_t, MetaspaceSize, NOT_LP64(16 * M) LP64_ONLY(21 * M), \
1384 "Initial threshold (in bytes) at which a garbage collection " \
1385 "is done to reduce Metaspace usage") \
1386 constraint(MetaspaceSizeConstraintFunc,AfterErgo) \
1387 \
1388 product(size_t, MaxMetaspaceSize, max_uintx, \
1389 "Maximum size of Metaspaces (in bytes)") \
1390 constraint(MaxMetaspaceSizeConstraintFunc,AfterErgo) \
1391 \
1392 product(size_t, CompressedClassSpaceSize, 1*G, \
1393 "Maximum size of class area in Metaspace when compressed " \
1394 "class pointers are used") \
1395 range(1*M, LP64_ONLY(4*G) NOT_LP64(max_uintx)) \
1396 \
1397 develop(size_t, CompressedClassSpaceBaseAddress, 0, \
1398 "Force the class space to be allocated at this address or " \
1399 "fails VM initialization (requires -Xshare=off.") \
1400 \
1401 develop(bool, RandomizeClassSpaceLocation, true, \
1402 "Randomize location of class space.") \
1403 \
1404 product(bool, PrintMetaspaceStatisticsAtExit, false, DIAGNOSTIC, \
1405 "Print metaspace statistics upon VM exit.") \
1406 \
1407 product(uintx, MinHeapFreeRatio, 40, MANAGEABLE, \
1408 "The minimum percentage of heap free after GC to avoid expansion."\
1409 " For most GCs this applies to the old generation. In G1 and" \
1410 " ParallelGC it applies to the whole heap.") \
1411 range(0, 100) \
1412 constraint(MinHeapFreeRatioConstraintFunc,AfterErgo) \
1413 \
1414 product(uintx, MaxHeapFreeRatio, 70, MANAGEABLE, \
1415 "The maximum percentage of heap free after GC to avoid shrinking."\
1416 " For most GCs this applies to the old generation. In G1 and" \
1417 " ParallelGC it applies to the whole heap.") \
1418 range(0, 100) \
1419 constraint(MaxHeapFreeRatioConstraintFunc,AfterErgo) \
1420 \
1421 product(intx, SoftRefLRUPolicyMSPerMB, 1000, \
1422 "Number of milliseconds per MB of free space in the heap") \
1423 range(0, max_intx) \
1424 constraint(SoftRefLRUPolicyMSPerMBConstraintFunc,AfterMemoryInit) \
1425 \
1426 product(size_t, MinHeapDeltaBytes, ScaleForWordSize(128*K), \
1427 "The minimum change in heap space due to GC (in bytes)") \
1428 range(0, max_uintx) \
1429 \
1430 product(size_t, MinMetaspaceExpansion, ScaleForWordSize(256*K), \
1431 "The minimum expansion of Metaspace (in bytes)") \
1432 range(0, max_uintx) \
1433 \
1434 product(uint, MaxMetaspaceFreeRatio, 70, \
1435 "The maximum percentage of Metaspace free after GC to avoid " \
1436 "shrinking") \
1437 range(0, 100) \
1438 constraint(MaxMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1439 \
1440 product(uint, MinMetaspaceFreeRatio, 40, \
1441 "The minimum percentage of Metaspace free after GC to avoid " \
1442 "expansion") \
1443 range(0, 99) \
1444 constraint(MinMetaspaceFreeRatioConstraintFunc,AfterErgo) \
1445 \
1446 product(size_t, MaxMetaspaceExpansion, ScaleForWordSize(4*M), \
1447 "The maximum expansion of Metaspace without full GC (in bytes)") \
1448 range(0, max_uintx) \
1449 \
1450 /* stack parameters */ \
1451 product_pd(intx, StackYellowPages, \
1452 "Number of yellow zone (recoverable overflows) pages of size " \
1453 "4KB. If pages are bigger yellow zone is aligned up.") \
1454 range(MIN_STACK_YELLOW_PAGES, (DEFAULT_STACK_YELLOW_PAGES+5)) \
1455 \
1456 product_pd(intx, StackRedPages, \
1457 "Number of red zone (unrecoverable overflows) pages of size " \
1458 "4KB. If pages are bigger red zone is aligned up.") \
1459 range(MIN_STACK_RED_PAGES, (DEFAULT_STACK_RED_PAGES+2)) \
1460 \
1461 product_pd(intx, StackReservedPages, \
1462 "Number of reserved zone (reserved to annotated methods) pages" \
1463 " of size 4KB. If pages are bigger reserved zone is aligned up.") \
1464 range(MIN_STACK_RESERVED_PAGES, (DEFAULT_STACK_RESERVED_PAGES+10))\
1465 \
1466 product(bool, RestrictReservedStack, true, \
1467 "Restrict @ReservedStackAccess to trusted classes") \
1468 \
1469 /* greater stack shadow pages can't generate instruction to bang stack */ \
1470 product_pd(intx, StackShadowPages, \
1471 "Number of shadow zone (for overflow checking) pages of size " \
1472 "4KB. If pages are bigger shadow zone is aligned up. " \
1473 "This should exceed the depth of the VM and native call stack.") \
1474 range(MIN_STACK_SHADOW_PAGES, (DEFAULT_STACK_SHADOW_PAGES+30)) \
1475 \
1476 product_pd(intx, ThreadStackSize, \
1477 "Thread Stack Size (in Kbytes)") \
1478 range(0, 1 * M) \
1479 \
1480 product_pd(intx, VMThreadStackSize, \
1481 "Non-Java Thread Stack Size (in Kbytes)") \
1482 range(0, max_intx/(1 * K)) \
1483 \
1484 product_pd(intx, CompilerThreadStackSize, \
1485 "Compiler Thread Stack Size (in Kbytes)") \
1486 range(0, max_intx/(1 * K)) \
1487 \
1488 develop_pd(size_t, JVMInvokeMethodSlack, \
1489 "Stack space (bytes) required for JVM_InvokeMethod to complete") \
1490 \
1491 /* code cache parameters */ \
1492 product_pd(uintx, CodeCacheSegmentSize, EXPERIMENTAL, \
1493 "Code cache segment size (in bytes) - smallest unit of " \
1494 "allocation") \
1495 range(1, 1024) \
1496 constraint(CodeCacheSegmentSizeConstraintFunc, AfterErgo) \
1497 \
1498 product_pd(intx, CodeEntryAlignment, EXPERIMENTAL, \
1499 "Code entry alignment for generated code (in bytes)") \
1500 constraint(CodeEntryAlignmentConstraintFunc, AfterErgo) \
1501 \
1502 product_pd(intx, OptoLoopAlignment, \
1503 "Align inner loops to zero relative to this modulus") \
1504 range(1, 128) \
1505 constraint(OptoLoopAlignmentConstraintFunc, AfterErgo) \
1506 \
1507 product_pd(uintx, InitialCodeCacheSize, \
1508 "Initial code cache size (in bytes)") \
1509 constraint(VMPageSizeConstraintFunc, AtParse) \
1510 \
1511 develop_pd(uintx, CodeCacheMinimumUseSpace, \
1512 "Minimum code cache size (in bytes) required to start VM.") \
1513 range(0, max_uintx) \
1514 \
1515 product(bool, SegmentedCodeCache, false, \
1516 "Use a segmented code cache") \
1517 \
1518 product_pd(uintx, ReservedCodeCacheSize, \
1519 "Reserved code cache size (in bytes) - maximum code cache size") \
1520 constraint(VMPageSizeConstraintFunc, AtParse) \
1521 \
1522 product_pd(uintx, NonProfiledCodeHeapSize, \
1523 "Size of code heap with non-profiled methods (in bytes)") \
1524 range(0, max_uintx) \
1525 \
1526 product_pd(uintx, ProfiledCodeHeapSize, \
1527 "Size of code heap with profiled methods (in bytes)") \
1528 range(0, max_uintx) \
1529 \
1530 product_pd(uintx, NonNMethodCodeHeapSize, \
1531 "Size of code heap with non-nmethods (in bytes)") \
1532 constraint(VMPageSizeConstraintFunc, AtParse) \
1533 \
1534 product_pd(uintx, CodeCacheExpansionSize, \
1535 "Code cache expansion size (in bytes)") \
1536 range(32*K, max_uintx) \
1537 \
1538 product_pd(uintx, CodeCacheMinBlockLength, DIAGNOSTIC, \
1539 "Minimum number of segments in a code cache block") \
1540 range(1, 100) \
1541 \
1542 develop(bool, ExitOnFullCodeCache, false, \
1543 "Exit the VM if we fill the code cache") \
1544 \
1545 product(bool, UseCodeCacheFlushing, true, \
1546 "Remove cold/old nmethods from the code cache") \
1547 \
1548 product(double, SweeperThreshold, 15.0, \
1549 "Threshold when a code cache unloading GC is invoked." \
1550 "Value is percentage of ReservedCodeCacheSize.") \
1551 range(0.0, 100.0) \
1552 \
1553 product(uintx, StartAggressiveSweepingAt, 10, \
1554 "Start aggressive sweeping if X[%] of the code cache is free." \
1555 "Segmented code cache: X[%] of the non-profiled heap." \
1556 "Non-segmented code cache: X[%] of the total code cache") \
1557 range(0, 100) \
1558 \
1559 /* interpreter debugging */ \
1560 develop(intx, BinarySwitchThreshold, 5, \
1561 "Minimal number of lookupswitch entries for rewriting to binary " \
1562 "switch") \
1563 \
1564 develop(intx, StopInterpreterAt, 0, \
1565 "Stop interpreter execution at specified bytecode number") \
1566 \
1567 develop(intx, TraceBytecodesAt, 0, \
1568 "Trace bytecodes starting with specified bytecode number") \
1569 \
1570 develop(intx, TraceBytecodesStopAt, 0, \
1571 "Stop bytecode tracing at the specified bytecode number") \
1572 \
1573 /* Priorities */ \
1574 product_pd(bool, UseThreadPriorities, "Use native thread priorities") \
1575 \
1576 product(int, ThreadPriorityPolicy, 0, \
1577 "0 : Normal. "\
1578 " VM chooses priorities that are appropriate for normal "\
1579 " applications. "\
1580 " On Windows applications are allowed to use higher native "\
1581 " priorities. However, with ThreadPriorityPolicy=0, VM will "\
1582 " not use the highest possible native priority, "\
1583 " THREAD_PRIORITY_TIME_CRITICAL, as it may interfere with "\
1584 " system threads. On Linux thread priorities are ignored "\
1585 " because the OS does not support static priority in "\
1586 " SCHED_OTHER scheduling class which is the only choice for "\
1587 " non-root, non-realtime applications. "\
1588 "1 : Aggressive. "\
1589 " Java thread priorities map over to the entire range of "\
1590 " native thread priorities. Higher Java thread priorities map "\
1591 " to higher native thread priorities. This policy should be "\
1592 " used with care, as sometimes it can cause performance "\
1593 " degradation in the application and/or the entire system. On "\
1594 " Linux/BSD/macOS this policy requires root privilege or an "\
1595 " extended capability.") \
1596 range(0, 1) \
1597 \
1598 product(bool, ThreadPriorityVerbose, false, \
1599 "Print priority changes") \
1600 \
1601 product(int, CompilerThreadPriority, -1, \
1602 "The native priority at which compiler threads should run " \
1603 "(-1 means no change)") \
1604 range(min_jint, max_jint) \
1605 \
1606 product(int, VMThreadPriority, -1, \
1607 "The native priority at which the VM thread should run " \
1608 "(-1 means no change)") \
1609 range(-1, 127) \
1610 \
1611 product(int, JavaPriority1_To_OSPriority, -1, \
1612 "Map Java priorities to OS priorities") \
1613 range(-1, 127) \
1614 \
1615 product(int, JavaPriority2_To_OSPriority, -1, \
1616 "Map Java priorities to OS priorities") \
1617 range(-1, 127) \
1618 \
1619 product(int, JavaPriority3_To_OSPriority, -1, \
1620 "Map Java priorities to OS priorities") \
1621 range(-1, 127) \
1622 \
1623 product(int, JavaPriority4_To_OSPriority, -1, \
1624 "Map Java priorities to OS priorities") \
1625 range(-1, 127) \
1626 \
1627 product(int, JavaPriority5_To_OSPriority, -1, \
1628 "Map Java priorities to OS priorities") \
1629 range(-1, 127) \
1630 \
1631 product(int, JavaPriority6_To_OSPriority, -1, \
1632 "Map Java priorities to OS priorities") \
1633 range(-1, 127) \
1634 \
1635 product(int, JavaPriority7_To_OSPriority, -1, \
1636 "Map Java priorities to OS priorities") \
1637 range(-1, 127) \
1638 \
1639 product(int, JavaPriority8_To_OSPriority, -1, \
1640 "Map Java priorities to OS priorities") \
1641 range(-1, 127) \
1642 \
1643 product(int, JavaPriority9_To_OSPriority, -1, \
1644 "Map Java priorities to OS priorities") \
1645 range(-1, 127) \
1646 \
1647 product(int, JavaPriority10_To_OSPriority,-1, \
1648 "Map Java priorities to OS priorities") \
1649 range(-1, 127) \
1650 \
1651 product(bool, UseCriticalJavaThreadPriority, false, EXPERIMENTAL, \
1652 "Java thread priority 10 maps to critical scheduling priority") \
1653 \
1654 product(bool, UseCriticalCompilerThreadPriority, false, EXPERIMENTAL, \
1655 "Compiler thread(s) run at critical scheduling priority") \
1656 \
1657 develop(intx, NewCodeParameter, 0, \
1658 "Testing Only: Create a dedicated integer parameter before " \
1659 "putback") \
1660 \
1661 /* new oopmap storage allocation */ \
1662 develop(intx, MinOopMapAllocation, 8, \
1663 "Minimum number of OopMap entries in an OopMapSet") \
1664 \
1665 /* recompilation */ \
1666 product_pd(intx, CompileThreshold, \
1667 "number of interpreted method invocations before (re-)compiling") \
1668 constraint(CompileThresholdConstraintFunc, AfterErgo) \
1669 \
1670 product_pd(bool, TieredCompilation, \
1671 "Enable tiered compilation") \
1672 \
1673 /* Properties for Java libraries */ \
1674 \
1675 product(uint64_t, MaxDirectMemorySize, 0, \
1676 "Maximum total size of NIO direct-buffer allocations. " \
1677 "Ignored if not explicitly set.") \
1678 range(0, max_jlong) \
1679 \
1680 /* Flags used for temporary code during development */ \
1681 \
1682 product(bool, UseNewCode, false, DIAGNOSTIC, \
1683 "Testing Only: Use the new version while testing") \
1684 \
1685 product(bool, UseNewCode2, false, DIAGNOSTIC, \
1686 "Testing Only: Use the new version while testing") \
1687 \
1688 product(bool, UseNewCode3, false, DIAGNOSTIC, \
1689 "Testing Only: Use the new version while testing") \
1690 \
1691 develop(bool, UseDebuggerErgo, false, \
1692 "Debugging Only: Adjust the VM to be more debugger-friendly. " \
1693 "Turns on the other UseDebuggerErgo* flags") \
1694 \
1695 develop(bool, UseDebuggerErgo1, false, \
1696 "Debugging Only: Enable workarounds for debugger induced " \
1697 "os::processor_id() >= os::processor_count() problems") \
1698 \
1699 develop(bool, UseDebuggerErgo2, false, \
1700 "Debugging Only: Limit the number of spawned JVM threads") \
1701 \
1702 develop(bool, EnableJVMTIStackDepthAsserts, true, \
1703 "Enable JVMTI asserts related to stack depth checks") \
1704 \
1705 /* flags for performance data collection */ \
1706 \
1707 product(bool, UsePerfData, true, \
1708 "Flag to disable jvmstat instrumentation for performance testing "\
1709 "and problem isolation purposes") \
1710 \
1711 product(bool, PerfDataSaveToFile, false, \
1712 "Save PerfData memory to hsperfdata_<pid> file on exit") \
1713 \
1714 product(ccstr, PerfDataSaveFile, nullptr, \
1715 "Save PerfData memory to the specified absolute pathname. " \
1716 "The string %p in the file name (if present) " \
1717 "will be replaced by pid") \
1718 \
1719 product(int, PerfDataSamplingInterval, 50, \
1720 "Data sampling interval (in milliseconds)") \
1721 range(PeriodicTask::min_interval, max_jint) \
1722 constraint(PerfDataSamplingIntervalFunc, AfterErgo) \
1723 \
1724 product(bool, PerfDisableSharedMem, false, \
1725 "Store performance data in standard memory") \
1726 \
1727 product(int, PerfDataMemorySize, 32*K, \
1728 "Size of performance data memory region. Will be rounded " \
1729 "up to a multiple of the native os page size.") \
1730 range(128, 32*64*K) \
1731 \
1732 product(int, PerfMaxStringConstLength, 1024, \
1733 "Maximum PerfStringConstant string length before truncation") \
1734 range(32, 32*K) \
1735 \
1736 product(bool, PerfAllowAtExitRegistration, false, \
1737 "Allow registration of atexit() methods") \
1738 \
1739 product(bool, PerfBypassFileSystemCheck, false, \
1740 "Bypass Win32 file system criteria checks (Windows Only)") \
1741 \
1742 product(int, UnguardOnExecutionViolation, 0, \
1743 "Unguard page and retry on no-execute fault (Win32 only) " \
1744 "0=off, 1=conservative, 2=aggressive") \
1745 range(0, 2) \
1746 \
1747 /* Serviceability Support */ \
1748 \
1749 product(bool, ManagementServer, false, \
1750 "Create JMX Management Server") \
1751 \
1752 product(bool, DisableAttachMechanism, false, \
1753 "Disable mechanism that allows tools to attach to this VM") \
1754 \
1755 product(bool, StartAttachListener, false, \
1756 "Always start Attach Listener at VM startup") \
1757 \
1758 product(bool, EnableDynamicAgentLoading, true, \
1759 "Allow tools to load agents with the attach mechanism") \
1760 \
1761 product(bool, PrintConcurrentLocks, false, MANAGEABLE, \
1762 "Print java.util.concurrent locks in thread dump") \
1763 \
1764 product(bool, PrintMethodHandleStubs, false, DIAGNOSTIC, \
1765 "Print generated stub code for method handles") \
1766 \
1767 product(bool, VerifyMethodHandles, trueInDebug, DIAGNOSTIC, \
1768 "perform extra checks when constructing method handles") \
1769 \
1770 product(bool, ShowHiddenFrames, false, DIAGNOSTIC, \
1771 "show method handle implementation frames (usually hidden)") \
1772 \
1773 product(bool, ShowCarrierFrames, false, DIAGNOSTIC, \
1774 "show virtual threads' carrier frames in exceptions") \
1775 \
1776 product(bool, TrustFinalNonStaticFields, false, EXPERIMENTAL, \
1777 "trust final non-static declarations for constant folding") \
1778 \
1779 product(bool, FoldStableValues, true, DIAGNOSTIC, \
1780 "Optimize loads from stable fields (marked w/ @Stable)") \
1781 \
1782 product(int, UseBootstrapCallInfo, 1, DIAGNOSTIC, \
1783 "0: when resolving InDy or ConDy, force all BSM arguments to be " \
1784 "resolved before the bootstrap method is called; 1: when a BSM " \
1785 "that may accept a BootstrapCallInfo is detected, use that API " \
1786 "to pass BSM arguments, which allows the BSM to delay their " \
1787 "resolution; 2+: stress test the BCI API by calling more BSMs " \
1788 "via that API, instead of with the eagerly-resolved array.") \
1789 \
1790 product(bool, PauseAtStartup, false, DIAGNOSTIC, \
1791 "Causes the VM to pause at startup time and wait for the pause " \
1792 "file to be removed (default: ./vm.paused.<pid>)") \
1793 \
1794 product(ccstr, PauseAtStartupFile, nullptr, DIAGNOSTIC, \
1795 "The file to create and for whose removal to await when pausing " \
1796 "at startup. (default: ./vm.paused.<pid>)") \
1797 \
1798 product(bool, PauseAtExit, false, DIAGNOSTIC, \
1799 "Pause and wait for keypress on exit if a debugger is attached") \
1800 \
1801 product(bool, DTraceMethodProbes, false, \
1802 "Enable dtrace tool probes for method-entry and method-exit") \
1803 \
1804 product(bool, DTraceAllocProbes, false, \
1805 "Enable dtrace tool probes for object allocation") \
1806 \
1807 product(bool, DTraceMonitorProbes, false, \
1808 "Enable dtrace tool probes for monitor events") \
1809 \
1810 product(bool, RelaxAccessControlCheck, false, \
1811 "Relax the access control checks in the verifier") \
1812 \
1813 product(uintx, StringTableSize, defaultStringTableSize, \
1814 "Number of buckets in the interned String table " \
1815 "(will be rounded to nearest higher power of 2)") \
1816 range(minimumStringTableSize, 16777216ul /* 2^24 */) \
1817 \
1818 product(uintx, SymbolTableSize, defaultSymbolTableSize, EXPERIMENTAL, \
1819 "Number of buckets in the JVM internal Symbol table") \
1820 range(minimumSymbolTableSize, 16777216ul /* 2^24 */) \
1821 \
1822 product(bool, UseStringDeduplication, false, \
1823 "Use string deduplication") \
1824 \
1825 product(uint, StringDeduplicationAgeThreshold, 3, \
1826 "A string must reach this age (or be promoted to an old region) " \
1827 "to be considered for deduplication") \
1828 range(1, markWord::max_age) \
1829 \
1830 product(size_t, StringDeduplicationInitialTableSize, 500, EXPERIMENTAL, \
1831 "Approximate initial number of buckets in the table") \
1832 range(1, 1 * G) \
1833 \
1834 product(double, StringDeduplicationGrowTableLoad, 14.0, EXPERIMENTAL, \
1835 "Entries per bucket above which the table should be expanded") \
1836 range(0.1, 1000.0) \
1837 \
1838 product(double, StringDeduplicationShrinkTableLoad, 1.0, EXPERIMENTAL, \
1839 "Entries per bucket below which the table should be shrunk") \
1840 range(0.01, 100.0) \
1841 \
1842 product(double, StringDeduplicationTargetTableLoad, 7.0, EXPERIMENTAL, \
1843 "Desired entries per bucket when resizing the table") \
1844 range(0.01, 1000.0) \
1845 \
1846 product(size_t, StringDeduplicationCleanupDeadMinimum, 100, EXPERIMENTAL, \
1847 "Minimum number of dead table entries for cleaning the table") \
1848 \
1849 product(int, StringDeduplicationCleanupDeadPercent, 5, EXPERIMENTAL, \
1850 "Minimum percentage of dead table entries for cleaning the table") \
1851 range(1, 100) \
1852 \
1853 product(bool, StringDeduplicationResizeALot, false, DIAGNOSTIC, \
1854 "Force more frequent table resizing") \
1855 \
1856 product(uint64_t, StringDeduplicationHashSeed, 0, DIAGNOSTIC, \
1857 "Seed for the table hashing function; 0 requests computed seed") \
1858 \
1859 product(bool, WhiteBoxAPI, false, DIAGNOSTIC, \
1860 "Enable internal testing APIs") \
1861 \
1862 product(bool, AlwaysAtomicAccesses, false, EXPERIMENTAL, \
1863 "Accesses to all variables should always be atomic") \
1864 \
1865 product(bool, UseUnalignedAccesses, false, DIAGNOSTIC, \
1866 "Use unaligned memory accesses in Unsafe") \
1867 \
1868 product_pd(bool, PreserveFramePointer, \
1869 "Use the FP register for holding the frame pointer " \
1870 "and not as a general purpose register.") \
1871 \
1872 product(size_t, AsyncLogBufferSize, 2*M, \
1873 "Memory budget (in bytes) for the buffer of Asynchronous " \
1874 "Logging (-Xlog:async).") \
1875 range(100*K, 50*M) \
1876 \
1877 product(bool, CheckIntrinsics, true, DIAGNOSTIC, \
1878 "When a class C is loaded, check that " \
1879 "(1) all intrinsics defined by the VM for class C are present "\
1880 "in the loaded class file and are marked with the " \
1881 "@IntrinsicCandidate annotation, that " \
1882 "(2) there is an intrinsic registered for all loaded methods " \
1883 "that are annotated with the @IntrinsicCandidate annotation, " \
1884 "and that " \
1885 "(3) no orphan methods exist for class C (i.e., methods for " \
1886 "which the VM declares an intrinsic but that are not declared "\
1887 "in the loaded class C. " \
1888 "Check (3) is available only in debug builds.") \
1889 \
1890 product_pd(intx, InitArrayShortSize, DIAGNOSTIC, \
1891 "Threshold small size (in bytes) for clearing arrays. " \
1892 "Anything this size or smaller may get converted to discrete " \
1893 "scalar stores.") \
1894 range(0, max_intx) \
1895 constraint(InitArrayShortSizeConstraintFunc, AfterErgo) \
1896 \
1897 product(ccstr, AllocateHeapAt, nullptr, \
1898 "Path to the directory where a temporary file will be created " \
1899 "to use as the backing store for Java Heap.") \
1900 \
1901 product_pd(bool, VMContinuations, EXPERIMENTAL, \
1902 "Enable VM continuations support") \
1903 \
1904 develop(bool, LoomDeoptAfterThaw, false, \
1905 "Deopt stack after thaw") \
1906 \
1907 develop(bool, LoomVerifyAfterThaw, false, \
1908 "Verify stack after thaw") \
1909 \
1910 develop(bool, VerifyContinuations, true, \
1911 "Verify continuation consistency") \
1912 \
1913 develop(bool, UseContinuationFastPath, true, \
1914 "Use fast-path frame walking in continuations") \
1915 \
1916 develop(int, VerifyMetaspaceInterval, DEBUG_ONLY(500) NOT_DEBUG(0), \
1917 "Run periodic metaspace verifications (0 - none, " \
1918 "1 - always, >1 every nth interval)") \
1919 \
1920 product(bool, ShowRegistersOnAssert, true, DIAGNOSTIC, \
1921 "On internal errors, include registers in error report.") \
1922 \
1923 product(bool, UseSwitchProfiling, true, DIAGNOSTIC, \
1924 "leverage profiling for table/lookup switch") \
1925 \
1926 develop(bool, TraceMemoryWriteback, false, \
1927 "Trace memory writeback operations") \
1928 \
1929 JFR_ONLY(product(bool, FlightRecorder, false, \
1930 "(Deprecated) Enable Flight Recorder")) \
1931 \
1932 JFR_ONLY(product(ccstr, FlightRecorderOptions, nullptr, \
1933 "Flight Recorder options")) \
1934 \
1935 JFR_ONLY(product(ccstr, StartFlightRecording, nullptr, \
1936 "Start flight recording with options")) \
1937 \
1938 product(bool, UseFastUnorderedTimeStamps, false, EXPERIMENTAL, \
1939 "Use platform unstable time where supported for timestamps only") \
1940 \
1941 product(bool, DeoptimizeNMethodBarriersALot, false, DIAGNOSTIC, \
1942 "Make nmethod barriers deoptimise a lot.") \
1943 \
1944 develop(bool, VerifyCrossModifyFence, \
1945 false AARCH64_ONLY(DEBUG_ONLY(||true)), \
1946 "Mark all threads after a safepoint, and clear on a modify " \
1947 "fence. Add cleanliness checks.") \
1948 \
1949 product(int, LockingMode, LM_LIGHTWEIGHT, \
1950 "(Deprecated) Select locking mode: " \
1951 "0: (Deprecated) monitors only (LM_MONITOR), " \
1952 "1: (Deprecated) monitors & legacy stack-locking (LM_LEGACY), " \
1953 "2: monitors & new lightweight locking (LM_LIGHTWEIGHT, default)") \
1954 range(0, 2) \
1955 \
1956 product(bool, UseObjectMonitorTable, false, DIAGNOSTIC, \
1957 "With Lightweight Locking mode, use a table to record inflated " \
1958 "monitors rather than the first word of the object.") \
1959 \
1960 product(int, LightweightFastLockingSpins, 13, DIAGNOSTIC, \
1961 "Specifies the number of times lightweight fast locking will " \
1962 "attempt to CAS the markWord before inflating. Between each " \
1963 "CAS it will spin for exponentially more time, resulting in " \
1964 "a total number of spins on the order of O(2^value)") \
1965 range(1, 30) \
1966 \
1967 product(uint, TrimNativeHeapInterval, 0, \
1968 "Interval, in ms, at which the JVM will trim the native heap if " \
1969 "the platform supports that. Lower values will reclaim memory " \
1970 "more eagerly at the cost of higher overhead. A value of 0 " \
1971 "(default) disables native heap trimming.") \
1972 range(0, UINT_MAX) \
1973 \
1974 develop(bool, SimulateFullAddressSpace, false, \
1975 "Simulates a very populated, fragmented address space; no " \
1976 "targeted reservations will succeed.") \
1977 \
1978 product(bool, ProfileExceptionHandlers, true, \
1979 "Profile exception handlers") \
1980 \
1981 product(bool, AlwaysRecordEvolDependencies, true, EXPERIMENTAL, \
1982 "Unconditionally record nmethod dependencies on class " \
1983 "rewriting/transformation independently of the JVMTI " \
1984 "can_{retransform/redefine}_classes capabilities.") \
1985 \
1986 product(bool, UseSecondarySupersCache, true, DIAGNOSTIC, \
1987 "Use secondary supers cache during subtype checks.") \
1988 \
1989 product(bool, UseSecondarySupersTable, false, DIAGNOSTIC, \
1990 "Use hash table to lookup secondary supers.") \
1991 \
1992 product(bool, VerifySecondarySupers, false, DIAGNOSTIC, \
1993 "Check that linear and hashed secondary lookups return the same result.") \
1994 \
1995 product(bool, StressSecondarySupers, false, DIAGNOSTIC, \
1996 "Use a terrible hash function in order to generate many collisions.") \
1997
1998 // end of RUNTIME_FLAGS
1999
2000 DECLARE_FLAGS(LP64_RUNTIME_FLAGS)
2001 DECLARE_ARCH_FLAGS(ARCH_FLAGS)
2002 DECLARE_FLAGS(RUNTIME_FLAGS)
2003 DECLARE_FLAGS(RUNTIME_OS_FLAGS)
2004
2005 #endif // SHARE_RUNTIME_GLOBALS_HPP