1 /*
2 * Copyright (c) 2010, 2025, 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 #include "cds/aotLinkedClassBulkLoader.hpp"
26 #include "code/aotCodeCache.hpp"
27 #include "code/scopeDesc.hpp"
28 #include "compiler/compilationPolicy.hpp"
29 #include "compiler/compileBroker.hpp"
30 #include "compiler/compilerDefinitions.inline.hpp"
31 #include "compiler/compilerOracle.hpp"
32 #include "compiler/recompilationPolicy.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "oops/method.inline.hpp"
35 #include "oops/methodData.hpp"
36 #include "oops/oop.inline.hpp"
37 #include "oops/trainingData.hpp"
38 #include "prims/jvmtiExport.hpp"
39 #include "runtime/arguments.hpp"
40 #include "runtime/deoptimization.hpp"
41 #include "runtime/frame.hpp"
42 #include "runtime/frame.inline.hpp"
43 #include "runtime/globals_extension.hpp"
44 #include "runtime/handles.inline.hpp"
45 #include "runtime/safepoint.hpp"
46 #include "runtime/safepointVerifiers.hpp"
47 #ifdef COMPILER1
48 #include "c1/c1_Compiler.hpp"
49 #endif
50 #ifdef COMPILER2
51 #include "opto/c2compiler.hpp"
52 #endif
53 #if INCLUDE_JVMCI
54 #include "jvmci/jvmci.hpp"
55 #endif
56
57 int64_t CompilationPolicy::_start_time = 0;
58 int CompilationPolicy::_c1_count = 0;
59 int CompilationPolicy::_c2_count = 0;
60 int CompilationPolicy::_c3_count = 0;
61 int CompilationPolicy::_ac_count = 0;
62 double CompilationPolicy::_increase_threshold_at_ratio = 0;
63
64 CompilationPolicy::TrainingReplayQueue CompilationPolicy::_training_replay_queue;
65
66 void compilationPolicy_init() {
67 CompilationPolicy::initialize();
68 }
69
70 int CompilationPolicy::compiler_count(CompLevel comp_level) {
71 if (is_c1_compile(comp_level)) {
72 return c1_count();
73 } else if (is_c2_compile(comp_level)) {
74 return c2_count();
75 }
76 return 0;
77 }
78
79 // Returns true if m must be compiled before executing it
80 // This is intended to force compiles for methods (usually for
81 // debugging) that would otherwise be interpreted for some reason.
82 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
83 // Don't allow Xcomp to cause compiles in replay mode
84 if (ReplayCompiles) return false;
85
86 if (m->has_compiled_code()) return false; // already compiled
87 if (!can_be_compiled(m, comp_level)) return false;
88
89 return !UseInterpreter || // must compile all methods
90 (AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
91 }
92
93 void CompilationPolicy::maybe_compile_early(const methodHandle& m, TRAPS) {
94 if (m->method_holder()->is_not_initialized()) {
95 // 'is_not_initialized' means not only '!is_initialized', but also that
96 // initialization has not been started yet ('!being_initialized')
97 // Do not force compilation of methods in uninitialized classes.
98 return;
99 }
100 if (!m->is_native() && MethodTrainingData::have_data()) {
101 MethodTrainingData* mtd = MethodTrainingData::find_fast(m);
102 if (mtd == nullptr) {
103 return; // there is no training data recorded for m
104 }
105 bool recompile = m->code_has_clinit_barriers();
106 CompLevel cur_level = static_cast<CompLevel>(m->highest_comp_level());
107 CompLevel next_level = trained_transition(m, cur_level, mtd, THREAD);
108 if ((next_level != cur_level || recompile) && can_be_compiled(m, next_level) && !CompileBroker::compilation_is_in_queue(m)) {
109 bool requires_online_compilation = false;
110 CompileTrainingData* ctd = mtd->last_toplevel_compile(next_level);
111 if (ctd != nullptr) {
112 requires_online_compilation = (ctd->init_deps_left() > 0);
113 }
114 if (requires_online_compilation && recompile) {
115 return;
116 }
117 if (PrintTieredEvents) {
118 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, next_level);
119 }
120 CompileBroker::compile_method(m, InvocationEntryBci, next_level, methodHandle(), 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
121 if (HAS_PENDING_EXCEPTION) {
122 CLEAR_PENDING_EXCEPTION;
123 }
124 }
125 }
126 }
127
128 void CompilationPolicy::maybe_compile_early_after_init(const methodHandle& m, TRAPS) {
129 assert(m->method_holder()->is_initialized(), "Should be called after class initialization");
130 maybe_compile_early(m, THREAD);
131 }
132
133 void CompilationPolicy::compile_if_required(const methodHandle& m, TRAPS) {
134 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
135 // don't force compilation, resolve was on behalf of compiler
136 return;
137 }
138 if (m->method_holder()->is_not_initialized()) {
139 // 'is_not_initialized' means not only '!is_initialized', but also that
140 // initialization has not been started yet ('!being_initialized')
141 // Do not force compilation of methods in uninitialized classes.
142 // Note that doing this would throw an assert later,
143 // in CompileBroker::compile_method.
144 // We sometimes use the link resolver to do reflective lookups
145 // even before classes are initialized.
146 return;
147 }
148
149 if (must_be_compiled(m)) {
150 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
151 CompLevel level = initial_compile_level(m);
152 if (PrintTieredEvents) {
153 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
154 }
155 CompileBroker::compile_method(m, InvocationEntryBci, level, methodHandle(), 0, false, CompileTask::Reason_MustBeCompiled, THREAD);
156 }
157 }
158
159 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, TRAPS) {
160 if (!klass->has_init_deps_processed()) {
161 ResourceMark rm;
162 log_debug(training)("Replay training: %s", klass->external_name());
163
164 KlassTrainingData* ktd = KlassTrainingData::find(klass);
165 if (ktd != nullptr) {
166 guarantee(ktd->has_holder(), "");
167 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
168 assert(klass->has_init_deps_processed(), "");
169
170 if (AOTCompileEagerly) {
171 ktd->iterate_comp_deps([&](CompileTrainingData* ctd) {
172 if (ctd->init_deps_left() == 0) {
173 MethodTrainingData* mtd = ctd->method();
174 if (mtd->has_holder()) {
175 const methodHandle mh(THREAD, const_cast<Method*>(mtd->holder()));
176 CompilationPolicy::maybe_compile_early(mh, THREAD);
177 }
178 }
179 });
180 }
181 }
182 }
183 }
184
185 void CompilationPolicy::flush_replay_training_at_init(TRAPS) {
186 MonitorLocker locker(THREAD, TrainingReplayQueue_lock);
187 while (!_training_replay_queue.is_empty_unlocked()) {
188 locker.wait(); // let the replay training thread drain the queue
189 }
190 }
191
192 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, TRAPS) {
193 assert(klass->is_initialized(), "");
194 if (TrainingData::have_data() && klass->is_shared()) {
195 _training_replay_queue.push(klass, TrainingReplayQueue_lock, THREAD);
196 }
197 }
198
199 // For TrainingReplayQueue
200 template<>
201 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
202 int pos = 0;
203 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
204 ResourceMark rm;
205 InstanceKlass* ik = cur->value();
206 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
207 }
208 }
209
210 void CompilationPolicy::replay_training_at_init_loop(TRAPS) {
211 while (!CompileBroker::is_compilation_disabled_forever() || AOTVerifyTrainingData) {
212 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, THREAD);
213 replay_training_at_init_impl(ik, THREAD);
214 }
215 }
216
217 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
218 if (comp_level == CompLevel_any) {
219 if (CompilerConfig::is_c1_only()) {
220 comp_level = CompLevel_simple;
221 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
222 comp_level = CompLevel_full_optimization;
223 }
224 }
225 return comp_level;
226 }
227
228 // Returns true if m is allowed to be compiled
229 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
230 // allow any levels for WhiteBox
231 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
232
233 if (m->is_abstract()) return false;
234 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
235
236 // Math intrinsics should never be compiled as this can lead to
237 // monotonicity problems because the interpreter will prefer the
238 // compiled code to the intrinsic version. This can't happen in
239 // production because the invocation counter can't be incremented
240 // but we shouldn't expose the system to this problem in testing
241 // modes.
242 if (!AbstractInterpreter::can_be_compiled(m)) {
243 return false;
244 }
245 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
246 if (comp_level == CompLevel_any || is_compile(comp_level)) {
247 return !m->is_not_compilable(comp_level);
248 }
249 return false;
250 }
251
252 // Returns true if m is allowed to be osr compiled
253 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
254 bool result = false;
255 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
256 if (comp_level == CompLevel_any || is_compile(comp_level)) {
257 result = !m->is_not_osr_compilable(comp_level);
258 }
259 return (result && can_be_compiled(m, comp_level));
260 }
261
262 bool CompilationPolicy::is_compilation_enabled() {
263 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
264 return CompileBroker::should_compile_new_jobs();
265 }
266
267 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
268 // Remove unloaded methods from the queue
269 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
270 CompileTask* next = task->next();
271 if (task->is_unloaded()) {
272 compile_queue->remove_and_mark_stale(task);
273 }
274 task = next;
275 }
276 #if INCLUDE_JVMCI
277 if (UseJVMCICompiler && !BackgroundCompilation) {
278 /*
279 * In blocking compilation mode, the CompileBroker will make
280 * compilations submitted by a JVMCI compiler thread non-blocking. These
281 * compilations should be scheduled after all blocking compilations
282 * to service non-compiler related compilations sooner and reduce the
283 * chance of such compilations timing out.
284 */
285 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
286 if (task->is_blocking()) {
287 return task;
288 }
289 }
290 }
291 #endif
292 return compile_queue->first();
293 }
294
295 // Simple methods are as good being compiled with C1 as C2.
296 // Determine if a given method is such a case.
297 bool CompilationPolicy::is_trivial(const methodHandle& method) {
298 if (method->is_accessor() ||
299 method->is_constant_getter()) {
300 return true;
301 }
302 return false;
303 }
304
305 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
306 if (CompilationModeFlag::quick_internal()) {
307 #if INCLUDE_JVMCI
308 if (UseJVMCICompiler) {
309 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
310 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
311 return !AOTCodeCache::is_C3_on();
312 }
313 }
314 #endif
315 }
316 return false;
317 }
318
319 CompLevel CompilationPolicy::comp_level(Method* method) {
320 nmethod *nm = method->code();
321 if (nm != nullptr && nm->is_in_use()) {
322 return (CompLevel)nm->comp_level();
323 }
324 return CompLevel_none;
325 }
326
327 // Call and loop predicates determine whether a transition to a higher
328 // compilation level should be performed (pointers to predicate functions
329 // are passed to common()).
330 // Tier?LoadFeedback is basically a coefficient that determines of
331 // how many methods per compiler thread can be in the queue before
332 // the threshold values double.
333 class LoopPredicate : AllStatic {
334 public:
335 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
336 double threshold_scaling;
337 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
338 scale *= threshold_scaling;
339 }
340 switch(cur_level) {
341 case CompLevel_none:
342 case CompLevel_limited_profile:
343 return b >= Tier3BackEdgeThreshold * scale;
344 case CompLevel_full_profile:
345 return b >= Tier4BackEdgeThreshold * scale;
346 default:
347 return true;
348 }
349 }
350
351 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
352 double k = 1;
353 switch(cur_level) {
354 case CompLevel_none:
355 // Fall through
356 case CompLevel_limited_profile: {
357 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
358 break;
359 }
360 case CompLevel_full_profile: {
361 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
362 break;
363 }
364 default:
365 return true;
366 }
367 return apply_scaled(method, cur_level, i, b, k);
368 }
369 };
370
371 class CallPredicate : AllStatic {
372 public:
373 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
374 double threshold_scaling;
375 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
376 scale *= threshold_scaling;
377 }
378 switch(cur_level) {
379 case CompLevel_none:
380 case CompLevel_limited_profile:
381 return (i >= Tier3InvocationThreshold * scale) ||
382 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
383 case CompLevel_full_profile:
384 return (i >= Tier4InvocationThreshold * scale) ||
385 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
386 default:
387 return true;
388 }
389 }
390
391 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
392 double k = 1;
393 switch(cur_level) {
394 case CompLevel_none:
395 case CompLevel_limited_profile: {
396 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
397 break;
398 }
399 case CompLevel_full_profile: {
400 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
401 break;
402 }
403 default:
404 return true;
405 }
406 return apply_scaled(method, cur_level, i, b, k);
407 }
408 };
409
410 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
411 int comp_count = compiler_count(level);
412 if (comp_count > 0) {
413 double queue_size = CompileBroker::queue_size(level);
414 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
415
416 // Increase C1 compile threshold when the code cache is filled more
417 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
418 // The main intention is to keep enough free space for C2 compiled code
419 // to achieve peak performance if the code cache is under stress.
420 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
421 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
422 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
423 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
424 }
425 }
426 return k;
427 }
428 return 1;
429 }
430
431 void CompilationPolicy::print_counters(const char* prefix, Method* m) {
432 int invocation_count = m->invocation_count();
433 int backedge_count = m->backedge_count();
434 MethodData* mdh = m->method_data();
435 int mdo_invocations = 0, mdo_backedges = 0;
436 int mdo_invocations_start = 0, mdo_backedges_start = 0;
437 if (mdh != nullptr) {
438 mdo_invocations = mdh->invocation_count();
439 mdo_backedges = mdh->backedge_count();
440 mdo_invocations_start = mdh->invocation_count_start();
441 mdo_backedges_start = mdh->backedge_count_start();
442 }
443 tty->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
444 invocation_count, backedge_count, prefix,
445 mdo_invocations, mdo_invocations_start,
446 mdo_backedges, mdo_backedges_start);
447 tty->print(" %smax levels=%d,%d", prefix,
448 m->highest_comp_level(), m->highest_osr_comp_level());
449 }
450
451 void CompilationPolicy::print_training_data(const char* prefix, Method* method) {
452 methodHandle m(Thread::current(), method);
453 tty->print(" %smtd: ", prefix);
454 MethodTrainingData* mtd = MethodTrainingData::find(m);
455 if (mtd == nullptr) {
456 tty->print("null");
457 } else {
458 MethodData* md = mtd->final_profile();
459 tty->print("mdo=");
460 if (md == nullptr) {
461 tty->print("null");
462 } else {
463 int mdo_invocations = md->invocation_count();
464 int mdo_backedges = md->backedge_count();
465 int mdo_invocations_start = md->invocation_count_start();
466 int mdo_backedges_start = md->backedge_count_start();
467 tty->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
468 }
469 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
470 tty->print(", deps=");
471 if (ctd == nullptr) {
472 tty->print("null");
473 } else {
474 tty->print("%d", ctd->init_deps_left());
475 }
476 }
477 }
478
479 // Print an event.
480 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
481 bool inlinee_event = m != im;
482
483 ttyLocker tty_lock;
484 tty->print("%lf: [", os::elapsedTime());
485
486 switch(type) {
487 case CALL:
488 tty->print("call");
489 break;
490 case LOOP:
491 tty->print("loop");
492 break;
493 case COMPILE:
494 tty->print("compile");
495 break;
496 case FORCE_COMPILE:
497 tty->print("force-compile");
498 break;
499 case FORCE_RECOMPILE:
500 tty->print("force-recompile");
501 break;
502 case REMOVE_FROM_QUEUE:
503 tty->print("remove-from-queue");
504 break;
505 case UPDATE_IN_QUEUE:
506 tty->print("update-in-queue");
507 break;
508 case REPROFILE:
509 tty->print("reprofile");
510 break;
511 case MAKE_NOT_ENTRANT:
512 tty->print("make-not-entrant");
513 break;
514 default:
515 tty->print("unknown");
516 }
517
518 tty->print(" level=%d ", level);
519
520 ResourceMark rm;
521 char *method_name = m->name_and_sig_as_C_string();
522 tty->print("[%s", method_name);
523 if (inlinee_event) {
524 char *inlinee_name = im->name_and_sig_as_C_string();
525 tty->print(" [%s]] ", inlinee_name);
526 }
527 else tty->print("] ");
528 tty->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
529 CompileBroker::queue_size(CompLevel_full_optimization));
530
531 tty->print(" rate=");
532 if (m->prev_time() == 0) tty->print("n/a");
533 else tty->print("%f", m->rate());
534
535 RecompilationPolicy::print_load_average();
536
537 tty->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
538 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
539
540 if (type != COMPILE) {
541 print_counters("", m);
542 if (inlinee_event) {
543 print_counters("inlinee ", im);
544 }
545 tty->print(" compilable=");
546 bool need_comma = false;
547 if (!m->is_not_compilable(CompLevel_full_profile)) {
548 tty->print("c1");
549 need_comma = true;
550 }
551 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
552 if (need_comma) tty->print(",");
553 tty->print("c1-osr");
554 need_comma = true;
555 }
556 if (!m->is_not_compilable(CompLevel_full_optimization)) {
557 if (need_comma) tty->print(",");
558 tty->print("c2");
559 need_comma = true;
560 }
561 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
562 if (need_comma) tty->print(",");
563 tty->print("c2-osr");
564 }
565 tty->print(" status=");
566 if (m->queued_for_compilation()) {
567 tty->print("in-queue");
568 } else tty->print("idle");
569 print_training_data("", m);
570 if (inlinee_event) {
571 print_training_data("inlinee ", im);
572 }
573 }
574 tty->print_cr("]");
575 }
576
577 void CompilationPolicy::initialize() {
578 if (!CompilerConfig::is_interpreter_only()) {
579 if (StoreCachedCode) {
580 // Assembly phase runs C1 and C2 compilation in separate phases,
581 // and can use all the CPU threads it can reach. Adjust the common
582 // options before policy starts overwriting them. There is a block
583 // at the very end that overrides final thread counts.
584 if (FLAG_IS_DEFAULT(UseDynamicNumberOfCompilerThreads)) {
585 FLAG_SET_ERGO(UseDynamicNumberOfCompilerThreads, false);
586 }
587 if (FLAG_IS_DEFAULT(CICompilerCount)) {
588 FLAG_SET_ERGO(CICompilerCount, MAX2(2, os::active_processor_count()));
589 }
590 }
591 int count = CICompilerCount;
592 bool c1_only = CompilerConfig::is_c1_only();
593 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
594
595 #ifdef _LP64
596 // Turn on ergonomic compiler count selection
597 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
598 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
599 }
600 if (CICompilerCountPerCPU) {
601 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
602 int log_cpu = log2i(os::active_processor_count());
603 int loglog_cpu = log2i(MAX2(log_cpu, 1));
604 count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2);
605 // Make sure there is enough space in the code cache to hold all the compiler buffers
606 size_t c1_size = 0;
607 #ifdef COMPILER1
608 c1_size = Compiler::code_buffer_size();
609 #endif
610 size_t c2_size = 0;
611 #ifdef COMPILER2
612 c2_size = C2Compiler::initial_code_buffer_size();
613 #endif
614 size_t buffer_size = c1_only ? c1_size : (c1_size/3 + 2*c2_size/3);
615 int max_count = (ReservedCodeCacheSize - (CodeCacheMinimumUseSpace DEBUG_ONLY(* 3))) / (int)buffer_size;
616 if (count > max_count) {
617 // Lower the compiler count such that all buffers fit into the code cache
618 count = MAX2(max_count, c1_only ? 1 : 2);
619 }
620 FLAG_SET_ERGO(CICompilerCount, count);
621 }
622 #else
623 // On 32-bit systems, the number of compiler threads is limited to 3.
624 // On these systems, the virtual address space available to the JVM
625 // is usually limited to 2-4 GB (the exact value depends on the platform).
626 // As the compilers (especially C2) can consume a large amount of
627 // memory, scaling the number of compiler threads with the number of
628 // available cores can result in the exhaustion of the address space
629 /// available to the VM and thus cause the VM to crash.
630 if (FLAG_IS_DEFAULT(CICompilerCount)) {
631 count = 3;
632 FLAG_SET_ERGO(CICompilerCount, count);
633 }
634 #endif
635
636 if (c1_only) {
637 // No C2 compiler thread required
638 set_c1_count(count);
639 } else if (c2_only) {
640 set_c2_count(count);
641 } else {
642 #if INCLUDE_JVMCI
643 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
644 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
645 int c1_count = MAX2(count - libjvmci_count, 1);
646 set_c2_count(libjvmci_count);
647 set_c1_count(c1_count);
648 } else if (AOTCodeCache::is_C3_on()) {
649 set_c1_count(MAX2(count / 3, 1));
650 set_c2_count(MAX2(count - c1_count(), 1));
651 set_c3_count(1);
652 } else
653 #endif
654 {
655 set_c1_count(MAX2(count / 3, 1));
656 set_c2_count(MAX2(count - c1_count(), 1));
657 }
658 }
659 if (StoreCachedCode) {
660 set_c1_count(count);
661 set_c2_count(count);
662 count *= 2; // satisfy the assert below
663 }
664 if (AOTCodeCache::is_code_load_thread_on()) {
665 set_ac_count((c1_only || c2_only) ? 1 : 2); // At minimum we need 2 threads to load C1 and C2 cached code in parallel
666 }
667 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
668 set_increase_threshold_at_ratio();
669 }
670
671 set_start_time(nanos_to_millis(os::javaTimeNanos()));
672 }
673
674
675
676
677 #ifdef ASSERT
678 bool CompilationPolicy::verify_level(CompLevel level) {
679 if (TieredCompilation && level > TieredStopAtLevel) {
680 return false;
681 }
682 // Check if there is a compiler to process the requested level
683 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
684 return false;
685 }
686 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
687 return false;
688 }
689
690 // Interpreter level is always valid.
691 if (level == CompLevel_none) {
692 return true;
693 }
694 if (CompilationModeFlag::normal()) {
695 return true;
696 } else if (CompilationModeFlag::quick_only()) {
697 return level == CompLevel_simple;
698 } else if (CompilationModeFlag::high_only()) {
699 return level == CompLevel_full_optimization;
700 } else if (CompilationModeFlag::high_only_quick_internal()) {
701 return level == CompLevel_full_optimization || level == CompLevel_simple;
702 }
703 return false;
704 }
705 #endif
706
707
708 CompLevel CompilationPolicy::highest_compile_level() {
709 CompLevel level = CompLevel_none;
710 // Setup the maximum level available for the current compiler configuration.
711 if (!CompilerConfig::is_interpreter_only()) {
712 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
713 level = CompLevel_full_optimization;
714 } else if (CompilerConfig::is_c1_enabled()) {
715 if (CompilerConfig::is_c1_simple_only()) {
716 level = CompLevel_simple;
717 } else {
718 level = CompLevel_full_profile;
719 }
720 }
721 }
722 // Clamp the maximum level with TieredStopAtLevel.
723 if (TieredCompilation) {
724 level = MIN2(level, (CompLevel) TieredStopAtLevel);
725 }
726
727 // Fix it up if after the clamping it has become invalid.
728 // Bring it monotonically down depending on the next available level for
729 // the compilation mode.
730 if (!CompilationModeFlag::normal()) {
731 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
732 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
733 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
734 if (CompilationModeFlag::quick_only()) {
735 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
736 level = CompLevel_simple;
737 }
738 } else if (CompilationModeFlag::high_only()) {
739 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
740 level = CompLevel_none;
741 }
742 } else if (CompilationModeFlag::high_only_quick_internal()) {
743 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
744 level = CompLevel_simple;
745 }
746 }
747 }
748
749 assert(verify_level(level), "Invalid highest compilation level: %d", level);
750 return level;
751 }
752
753 CompLevel CompilationPolicy::limit_level(CompLevel level) {
754 level = MIN2(level, highest_compile_level());
755 assert(verify_level(level), "Invalid compilation level: %d", level);
756 return level;
757 }
758
759 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
760 CompLevel level = CompLevel_any;
761 if (CompilationModeFlag::normal()) {
762 level = CompLevel_full_profile;
763 } else if (CompilationModeFlag::quick_only()) {
764 level = CompLevel_simple;
765 } else if (CompilationModeFlag::high_only()) {
766 level = CompLevel_full_optimization;
767 } else if (CompilationModeFlag::high_only_quick_internal()) {
768 if (force_comp_at_level_simple(method)) {
769 level = CompLevel_simple;
770 } else {
771 level = CompLevel_full_optimization;
772 }
773 }
774 assert(level != CompLevel_any, "Unhandled compilation mode");
775 return limit_level(level);
776 }
777
778 // Set carry flags on the counters if necessary
779 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
780 MethodCounters *mcs = method->method_counters();
781 if (mcs != nullptr) {
782 mcs->invocation_counter()->set_carry_on_overflow();
783 mcs->backedge_counter()->set_carry_on_overflow();
784 }
785 MethodData* mdo = method->method_data();
786 if (mdo != nullptr) {
787 mdo->invocation_counter()->set_carry_on_overflow();
788 mdo->backedge_counter()->set_carry_on_overflow();
789 }
790 }
791
792 // Called with the queue locked and with at least one element
793 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
794 CompileTask *max_blocking_task = nullptr;
795 CompileTask *max_task = nullptr;
796 Method* max_method = nullptr;
797
798 int64_t t = nanos_to_millis(os::javaTimeNanos());
799 // Iterate through the queue and find a method with a maximum rate.
800 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
801 CompileTask* next_task = task->next();
802 // If a method was unloaded or has been stale for some time, remove it from the queue.
803 // Blocking tasks and tasks submitted from whitebox API don't become stale
804 if (task->is_unloaded()) {
805 compile_queue->remove_and_mark_stale(task);
806 task = next_task;
807 continue;
808 }
809 if (task->is_aot()) {
810 // AOTCodeCache tasks are on separate queue, and they should load fast. There is no need to walk
811 // the rest of the queue, just take the task and go.
812 return task;
813 }
814 if (task->is_blocking() && task->compile_reason() == CompileTask::Reason_Whitebox) {
815 // CTW tasks, submitted as blocking Whitebox requests, do not participate in rate
816 // selection and/or any level adjustments. Just return them in order.
817 return task;
818 }
819 Method* method = task->method();
820 methodHandle mh(THREAD, method);
821 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
822 if (PrintTieredEvents) {
823 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
824 }
825 method->clear_queued_for_compilation();
826 method->set_pending_queue_processed(false);
827 compile_queue->remove_and_mark_stale(task);
828 task = next_task;
829 continue;
830 }
831 update_rate(t, mh);
832 if (max_task == nullptr || compare_methods(method, max_method) || compare_tasks(task, max_task)) {
833 // Select a method with the highest rate
834 max_task = task;
835 max_method = method;
836 }
837
838 if (task->is_blocking()) {
839 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
840 max_blocking_task = task;
841 }
842 }
843
844 task = next_task;
845 }
846
847 if (max_blocking_task != nullptr) {
848 // In blocking compilation mode, the CompileBroker will make
849 // compilations submitted by a JVMCI compiler thread non-blocking. These
850 // compilations should be scheduled after all blocking compilations
851 // to service non-compiler related compilations sooner and reduce the
852 // chance of such compilations timing out.
853 max_task = max_blocking_task;
854 max_method = max_task->method();
855 }
856
857 methodHandle max_method_h(THREAD, max_method);
858
859 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
860 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
861 max_task->set_comp_level(CompLevel_limited_profile);
862
863 if (CompileBroker::compilation_is_complete(max_method_h(), max_task->osr_bci(), CompLevel_limited_profile,
864 false /* requires_online_compilation */,
865 CompileTask::Reason_None)) {
866 if (PrintTieredEvents) {
867 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
868 }
869 compile_queue->remove_and_mark_stale(max_task);
870 max_method->clear_queued_for_compilation();
871 return nullptr;
872 }
873
874 if (PrintTieredEvents) {
875 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
876 }
877 }
878 return max_task;
879 }
880
881 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
882 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
883 if (PrintTieredEvents) {
884 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
885 }
886 MethodData* mdo = sd->method()->method_data();
887 if (mdo != nullptr) {
888 mdo->reset_start_counters();
889 }
890 if (sd->is_top()) break;
891 }
892 }
893
894 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
895 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
896 if (PrintTieredEvents) {
897 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
898 }
899
900 #if INCLUDE_JVMCI
901 if (EnableJVMCI && UseJVMCICompiler &&
902 comp_level == CompLevel_full_optimization CDS_ONLY(&& !AOTLinkedClassBulkLoader::class_preloading_finished())) {
903 return nullptr;
904 }
905 #endif
906
907 if (comp_level == CompLevel_none &&
908 JvmtiExport::can_post_interpreter_events() &&
909 THREAD->is_interp_only_mode()) {
910 return nullptr;
911 }
912 if (ReplayCompiles) {
913 // Don't trigger other compiles in testing mode
914 return nullptr;
915 }
916
917 handle_counter_overflow(method);
918 if (method() != inlinee()) {
919 handle_counter_overflow(inlinee);
920 }
921
922 if (bci == InvocationEntryBci) {
923 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
924 } else {
925 // method == inlinee if the event originated in the main method
926 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
927 // Check if event led to a higher level OSR compilation
928 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
929 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
930 // It's not possible to reach the expected level so fall back to simple.
931 expected_comp_level = CompLevel_simple;
932 }
933 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
934 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
935 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
936 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
937 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
938 // Perform OSR with new nmethod
939 return osr_nm;
940 }
941 }
942 }
943 return nullptr;
944 }
945
946 // Check if the method can be compiled, change level if necessary
947 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
948 assert(verify_level(level), "Invalid compilation level requested: %d", level);
949
950 if (level == CompLevel_none) {
951 if (mh->has_compiled_code()) {
952 // Happens when we switch to interpreter to profile.
953 MutexLocker ml(Compile_lock);
954 NoSafepointVerifier nsv;
955 if (mh->has_compiled_code()) {
956 mh->code()->make_not_used();
957 }
958 // Deoptimize immediately (we don't have to wait for a compile).
959 JavaThread* jt = THREAD;
960 RegisterMap map(jt,
961 RegisterMap::UpdateMap::skip,
962 RegisterMap::ProcessFrames::include,
963 RegisterMap::WalkContinuation::skip);
964 frame fr = jt->last_frame().sender(&map);
965 Deoptimization::deoptimize_frame(jt, fr.id());
966 }
967 return;
968 }
969
970 if (!CompilationModeFlag::disable_intermediate()) {
971 // Check if the method can be compiled. If it cannot be compiled with C1, continue profiling
972 // in the interpreter and then compile with C2 (the transition function will request that,
973 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
974 // pure C1.
975 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
976 if (level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
977 compile(mh, bci, CompLevel_simple, THREAD);
978 }
979 return;
980 }
981 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
982 if (level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
983 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
984 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
985 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
986 osr_nm->make_not_entrant("OSR invalidation for compiling with C1");
987 }
988 compile(mh, bci, CompLevel_simple, THREAD);
989 }
990 return;
991 }
992 }
993 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
994 return;
995 }
996 if (!CompileBroker::compilation_is_in_queue(mh)) {
997 if (PrintTieredEvents) {
998 print_event(COMPILE, mh(), mh(), bci, level);
999 }
1000 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
1001 update_rate(nanos_to_millis(os::javaTimeNanos()), mh);
1002 bool requires_online_compilation = false;
1003 if (TrainingData::have_data()) {
1004 MethodTrainingData* mtd = MethodTrainingData::find_fast(mh);
1005 if (mtd != nullptr) {
1006 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
1007 if (ctd != nullptr) {
1008 requires_online_compilation = (ctd->init_deps_left() > 0);
1009 }
1010 }
1011 }
1012 CompileBroker::compile_method(mh, bci, level, mh, hot_count, requires_online_compilation, CompileTask::Reason_Tiered, THREAD);
1013 }
1014 }
1015
1016 // update_rate() is called from select_task() while holding a compile queue lock.
1017 void CompilationPolicy::update_rate(int64_t t, const methodHandle& method) {
1018 // Skip update if counters are absent.
1019 // Can't allocate them since we are holding compile queue lock.
1020 if (method->method_counters() == nullptr) return;
1021
1022 if (is_old(method)) {
1023 // We don't remove old methods from the queue,
1024 // so we can just zero the rate.
1025 method->set_rate(0);
1026 return;
1027 }
1028
1029 // We don't update the rate if we've just came out of a safepoint.
1030 // delta_s is the time since last safepoint in milliseconds.
1031 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1032 int64_t delta_t = t - (method->prev_time() != 0 ? method->prev_time() : start_time()); // milliseconds since the last measurement
1033 // How many events were there since the last time?
1034 int event_count = method->invocation_count() + method->backedge_count();
1035 int delta_e = event_count - method->prev_event_count();
1036
1037 // We should be running for at least 1ms.
1038 if (delta_s >= TieredRateUpdateMinTime) {
1039 // And we must've taken the previous point at least 1ms before.
1040 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
1041 method->set_prev_time(t);
1042 method->set_prev_event_count(event_count);
1043 method->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
1044 } else {
1045 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
1046 // If nothing happened for 25ms, zero the rate. Don't modify prev values.
1047 method->set_rate(0);
1048 }
1049 }
1050 }
1051 }
1052
1053 // Check if this method has been stale for a given number of milliseconds.
1054 // See select_task().
1055 bool CompilationPolicy::is_stale(int64_t t, int64_t timeout, const methodHandle& method) {
1056 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1057 int64_t delta_t = t - method->prev_time();
1058 if (delta_t > timeout && delta_s > timeout) {
1059 int event_count = method->invocation_count() + method->backedge_count();
1060 int delta_e = event_count - method->prev_event_count();
1061 // Return true if there were no events.
1062 return delta_e == 0;
1063 }
1064 return false;
1065 }
1066
1067 // We don't remove old methods from the compile queue even if they have
1068 // very low activity. See select_task().
1069 bool CompilationPolicy::is_old(const methodHandle& method) {
1070 int i = method->invocation_count();
1071 int b = method->backedge_count();
1072 double k = TieredOldPercentage / 100.0;
1073
1074 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1075 }
1076
1077 double CompilationPolicy::weight(Method* method) {
1078 return (double)(method->rate() + 1) * (method->invocation_count() + 1) * (method->backedge_count() + 1);
1079 }
1080
1081 // Apply heuristics and return true if x should be compiled before y
1082 bool CompilationPolicy::compare_methods(Method* x, Method* y) {
1083 if (x->highest_comp_level() > y->highest_comp_level()) {
1084 // recompilation after deopt
1085 return true;
1086 } else
1087 if (x->highest_comp_level() == y->highest_comp_level()) {
1088 if (weight(x) > weight(y)) {
1089 return true;
1090 }
1091 }
1092 return false;
1093 }
1094
1095 bool CompilationPolicy::compare_tasks(CompileTask* x, CompileTask* y) {
1096 assert(!x->is_aot() && !y->is_aot(), "AOT code caching tasks are not expected here");
1097 if (x->compile_reason() != y->compile_reason() && y->compile_reason() == CompileTask::Reason_MustBeCompiled) {
1098 return true;
1099 }
1100 return false;
1101 }
1102
1103 // Is method profiled enough?
1104 bool CompilationPolicy::is_method_profiled(const methodHandle& method) {
1105 MethodData* mdo = method->method_data();
1106 if (mdo != nullptr) {
1107 int i = mdo->invocation_count_delta();
1108 int b = mdo->backedge_count_delta();
1109 return CallPredicate::apply_scaled(method, CompLevel_full_profile, i, b, 1);
1110 }
1111 return false;
1112 }
1113
1114
1115 // Determine is a method is mature.
1116 bool CompilationPolicy::is_mature(MethodData* mdo) {
1117 if (Arguments::is_compiler_only()) {
1118 // Always report profiles as immature with -Xcomp
1119 return false;
1120 }
1121 methodHandle mh(Thread::current(), mdo->method());
1122 if (mdo != nullptr) {
1123 int i = mdo->invocation_count();
1124 int b = mdo->backedge_count();
1125 double k = ProfileMaturityPercentage / 100.0;
1126 return CallPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k) || LoopPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k);
1127 }
1128 return false;
1129 }
1130
1131 // If a method is old enough and is still in the interpreter we would want to
1132 // start profiling without waiting for the compiled method to arrive.
1133 // We also take the load on compilers into the account.
1134 bool CompilationPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) {
1135 if (cur_level != CompLevel_none || force_comp_at_level_simple(method) || CompilationModeFlag::quick_only() || !ProfileInterpreter) {
1136 return false;
1137 }
1138
1139 if (TrainingData::have_data()) {
1140 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1141 if (mtd != nullptr && mtd->saw_level(CompLevel_full_optimization)) {
1142 return true;
1143 }
1144 }
1145
1146 if (is_old(method)) {
1147 return true;
1148 }
1149
1150 int i = method->invocation_count();
1151 int b = method->backedge_count();
1152 double k = Tier0ProfilingStartPercentage / 100.0;
1153
1154 // If the top level compiler is not keeping up, delay profiling.
1155 if (CompileBroker::queue_size(CompLevel_full_optimization) <= Tier0Delay * compiler_count(CompLevel_full_optimization)) {
1156 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1157 }
1158 return false;
1159 }
1160
1161 // Inlining control: if we're compiling a profiled method with C1 and the callee
1162 // is known to have OSRed in a C2 version, don't inline it.
1163 bool CompilationPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
1164 CompLevel comp_level = (CompLevel)env->comp_level();
1165 if (comp_level == CompLevel_full_profile ||
1166 comp_level == CompLevel_limited_profile) {
1167 return callee->highest_osr_comp_level() == CompLevel_full_optimization;
1168 }
1169 return false;
1170 }
1171
1172 // Create MDO if necessary.
1173 void CompilationPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
1174 if (mh->is_native() ||
1175 mh->is_abstract() ||
1176 mh->is_accessor() ||
1177 mh->is_constant_getter()) {
1178 return;
1179 }
1180 if (mh->method_data() == nullptr) {
1181 Method::build_profiling_method_data(mh, CHECK_AND_CLEAR);
1182 }
1183 if (ProfileInterpreter && THREAD->has_last_Java_frame()) {
1184 MethodData* mdo = mh->method_data();
1185 if (mdo != nullptr) {
1186 frame last_frame = THREAD->last_frame();
1187 if (last_frame.is_interpreted_frame() && mh == last_frame.interpreter_frame_method()) {
1188 int bci = last_frame.interpreter_frame_bci();
1189 address dp = mdo->bci_to_dp(bci);
1190 last_frame.interpreter_frame_set_mdp(dp);
1191 }
1192 }
1193 }
1194 }
1195
1196 CompLevel CompilationPolicy::trained_transition_from_none(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1197 precond(mtd != nullptr);
1198 precond(cur_level == CompLevel_none);
1199
1200 if (mtd->only_inlined() && !mtd->saw_level(CompLevel_full_optimization)) {
1201 return CompLevel_none;
1202 }
1203
1204 bool training_has_profile = (mtd->final_profile() != nullptr);
1205 if (mtd->saw_level(CompLevel_full_optimization) && !training_has_profile) {
1206 return CompLevel_full_profile;
1207 }
1208
1209 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1210 switch (highest_training_level) {
1211 case CompLevel_limited_profile:
1212 case CompLevel_full_profile:
1213 return CompLevel_limited_profile;
1214 case CompLevel_simple:
1215 return CompLevel_simple;
1216 case CompLevel_none:
1217 return CompLevel_none;
1218 default:
1219 break;
1220 }
1221
1222 // Now handle the case of level 4.
1223 assert(highest_training_level == CompLevel_full_optimization, "Unexpected compilation level: %d", highest_training_level);
1224 if (!training_has_profile) {
1225 // The method was a part of a level 4 compile, but don't have a stored profile,
1226 // we need to profile it.
1227 return CompLevel_full_profile;
1228 }
1229 const bool deopt = (static_cast<CompLevel>(method->highest_comp_level()) == CompLevel_full_optimization);
1230 // If we deopted, then we reprofile
1231 if (deopt && !is_method_profiled(method)) {
1232 return CompLevel_full_profile;
1233 }
1234
1235 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1236 assert(ctd != nullptr, "Should have CTD for CompLevel_full_optimization");
1237 // With SkipTier2IfPossible and all deps satisfied, go to level 4 immediately
1238 if (SkipTier2IfPossible && ctd->init_deps_left() == 0) {
1239 if (method->method_data() == nullptr) {
1240 create_mdo(method, THREAD);
1241 }
1242 return CompLevel_full_optimization;
1243 }
1244
1245 // Otherwise go to level 2
1246 return CompLevel_limited_profile;
1247 }
1248
1249
1250 CompLevel CompilationPolicy::trained_transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1251 precond(mtd != nullptr);
1252 precond(cur_level == CompLevel_limited_profile);
1253
1254 // One of the main reasons that we can get here is that we're waiting for the stored C2 code to become ready.
1255
1256 // But first, check if we have a saved profile
1257 bool training_has_profile = (mtd->final_profile() != nullptr);
1258 if (!training_has_profile) {
1259 return CompLevel_full_profile;
1260 }
1261
1262
1263 assert(training_has_profile, "Have to have a profile to be here");
1264 // Check if the method is ready
1265 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1266 if (ctd != nullptr && ctd->init_deps_left() == 0) {
1267 if (method->method_data() == nullptr) {
1268 create_mdo(method, THREAD);
1269 }
1270 return CompLevel_full_optimization;
1271 }
1272
1273 // Otherwise stay at the current level
1274 return CompLevel_limited_profile;
1275 }
1276
1277
1278 CompLevel CompilationPolicy::trained_transition_from_full_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1279 precond(mtd != nullptr);
1280 precond(cur_level == CompLevel_full_profile);
1281
1282 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1283 // We have method at the full profile level and we also know that it's possibly an important method.
1284 if (highest_training_level == CompLevel_full_optimization && !mtd->only_inlined()) {
1285 // Check if it is adequately profiled
1286 if (is_method_profiled(method)) {
1287 return CompLevel_full_optimization;
1288 }
1289 }
1290
1291 // Otherwise stay at the current level
1292 return CompLevel_full_profile;
1293 }
1294
1295 CompLevel CompilationPolicy::trained_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1296 precond(MethodTrainingData::have_data());
1297
1298 // If there is no training data recorded for this method, bail out.
1299 if (mtd == nullptr) {
1300 return cur_level;
1301 }
1302
1303 CompLevel next_level = cur_level;
1304 switch(cur_level) {
1305 default: break;
1306 case CompLevel_none:
1307 next_level = trained_transition_from_none(method, cur_level, mtd, THREAD);
1308 break;
1309 case CompLevel_limited_profile:
1310 next_level = trained_transition_from_limited_profile(method, cur_level, mtd, THREAD);
1311 break;
1312 case CompLevel_full_profile:
1313 next_level = trained_transition_from_full_profile(method, cur_level, mtd, THREAD);
1314 break;
1315 }
1316
1317 // We don't have any special strategies for the C2-only compilation modes, so just fix up the levels for now.
1318 if (CompilationModeFlag::high_only_quick_internal() && CompLevel_simple < next_level && next_level < CompLevel_full_optimization) {
1319 return CompLevel_none;
1320 }
1321 if (CompilationModeFlag::high_only() && next_level < CompLevel_full_optimization) {
1322 return CompLevel_none;
1323 }
1324 return (cur_level != next_level) ? limit_level(next_level) : cur_level;
1325 }
1326
1327 /*
1328 * Method states:
1329 * 0 - interpreter (CompLevel_none)
1330 * 1 - pure C1 (CompLevel_simple)
1331 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
1332 * 3 - C1 with full profiling (CompLevel_full_profile)
1333 * 4 - C2 or Graal (CompLevel_full_optimization)
1334 *
1335 * Common state transition patterns:
1336 * a. 0 -> 3 -> 4.
1337 * The most common path. But note that even in this straightforward case
1338 * profiling can start at level 0 and finish at level 3.
1339 *
1340 * b. 0 -> 2 -> 3 -> 4.
1341 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
1342 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
1343 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
1344 *
1345 * c. 0 -> (3->2) -> 4.
1346 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
1347 * to enable the profiling to fully occur at level 0. In this case we change the compilation level
1348 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
1349 * without full profiling while c2 is compiling.
1350 *
1351 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
1352 * After a method was once compiled with C1 it can be identified as trivial and be compiled to
1353 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
1354 *
1355 * e. 0 -> 4.
1356 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
1357 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
1358 * the compiled version already exists).
1359 *
1360 * Note that since state 0 can be reached from any other state via deoptimization different loops
1361 * are possible.
1362 *
1363 */
1364
1365 // Common transition function. Given a predicate determines if a method should transition to another level.
1366 template<typename Predicate>
1367 CompLevel CompilationPolicy::common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback) {
1368 CompLevel next_level = cur_level;
1369
1370 if (force_comp_at_level_simple(method)) {
1371 next_level = CompLevel_simple;
1372 } else if (is_trivial(method) || method->is_native()) {
1373 // We do not care if there is profiling data for these methods, throw them to compiler.
1374 next_level = CompilationModeFlag::disable_intermediate() ? CompLevel_full_optimization : CompLevel_simple;
1375 } else if (MethodTrainingData::have_data()) {
1376 MethodTrainingData* mtd = MethodTrainingData::find_fast(method);
1377 if (mtd == nullptr) {
1378 // We haven't see compilations of this method in training. It's either very cold or the behavior changed.
1379 // Feed it to the standard TF with no profiling delay.
1380 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1381 } else {
1382 next_level = trained_transition(method, cur_level, mtd, THREAD);
1383 if (cur_level == next_level) {
1384 // trained_transtion() is going to return the same level if no startup/warmup optimizations apply.
1385 // In order to catch possible pathologies due to behavior change we feed the event to the regular
1386 // TF but with profiling delay.
1387 next_level = standard_transition<Predicate>(method, cur_level, true /*delay_profiling*/, disable_feedback);
1388 }
1389 }
1390 } else {
1391 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1392 }
1393 return (next_level != cur_level) ? limit_level(next_level) : next_level;
1394 }
1395
1396
1397 template<typename Predicate>
1398 CompLevel CompilationPolicy::standard_transition(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1399 CompLevel next_level = cur_level;
1400 switch(cur_level) {
1401 default: break;
1402 case CompLevel_none:
1403 next_level = transition_from_none<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1404 break;
1405 case CompLevel_limited_profile:
1406 next_level = transition_from_limited_profile<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1407 break;
1408 case CompLevel_full_profile:
1409 next_level = transition_from_full_profile<Predicate>(method, cur_level);
1410 break;
1411 }
1412 return next_level;
1413 }
1414
1415 template<typename Predicate>
1416 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1417 precond(cur_level == CompLevel_none);
1418 CompLevel next_level = cur_level;
1419 int i = method->invocation_count();
1420 int b = method->backedge_count();
1421 double scale = delay_profiling ? Tier0ProfileDelayFactor : 1.0;
1422 // If we were at full profile level, would we switch to full opt?
1423 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1424 next_level = CompLevel_full_optimization;
1425 } else if (!CompilationModeFlag::disable_intermediate() && Predicate::apply_scaled(method, cur_level, i, b, scale)) {
1426 // C1-generated fully profiled code is about 30% slower than the limited profile
1427 // code that has only invocation and backedge counters. The observation is that
1428 // if C2 queue is large enough we can spend too much time in the fully profiled code
1429 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1430 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1431 // we choose to compile a limited profiled version and then recompile with full profiling
1432 // when the load on C2 goes down.
1433 if (delay_profiling || (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization))) {
1434 next_level = CompLevel_limited_profile;
1435 } else {
1436 next_level = CompLevel_full_profile;
1437 }
1438 }
1439 return next_level;
1440 }
1441
1442 template<typename Predicate>
1443 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1444 precond(cur_level == CompLevel_full_profile);
1445 CompLevel next_level = cur_level;
1446 MethodData* mdo = method->method_data();
1447 if (mdo != nullptr) {
1448 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1449 int mdo_i = mdo->invocation_count_delta();
1450 int mdo_b = mdo->backedge_count_delta();
1451 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1452 next_level = CompLevel_full_optimization;
1453 }
1454 } else {
1455 next_level = CompLevel_full_optimization;
1456 }
1457 }
1458 return next_level;
1459 }
1460
1461 template<typename Predicate>
1462 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1463 precond(cur_level == CompLevel_limited_profile);
1464 CompLevel next_level = cur_level;
1465 int i = method->invocation_count();
1466 int b = method->backedge_count();
1467 double scale = delay_profiling ? Tier2ProfileDelayFactor : 1.0;
1468 MethodData* mdo = method->method_data();
1469 if (mdo != nullptr) {
1470 if (mdo->would_profile()) {
1471 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1472 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1473 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1474 next_level = CompLevel_full_profile;
1475 }
1476 } else {
1477 next_level = CompLevel_full_optimization;
1478 }
1479 } else {
1480 // If there is no MDO we need to profile
1481 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1482 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1483 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1484 next_level = CompLevel_full_profile;
1485 }
1486 }
1487 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1488 next_level = CompLevel_full_optimization;
1489 }
1490 return next_level;
1491 }
1492
1493
1494 // Determine if a method should be compiled with a normal entry point at a different level.
1495 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1496 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1497 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1498
1499 // If OSR method level is greater than the regular method level, the levels should be
1500 // equalized by raising the regular method level in order to avoid OSRs during each
1501 // invocation of the method.
1502 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1503 MethodData* mdo = method->method_data();
1504 guarantee(mdo != nullptr, "MDO should not be nullptr");
1505 if (mdo->invocation_count() >= 1) {
1506 next_level = CompLevel_full_optimization;
1507 }
1508 } else {
1509 next_level = MAX2(osr_level, next_level);
1510 }
1511 #if INCLUDE_JVMCI
1512 if (EnableJVMCI && UseJVMCICompiler &&
1513 next_level == CompLevel_full_optimization CDS_ONLY(&& !AOTLinkedClassBulkLoader::class_preloading_finished())) {
1514 next_level = cur_level;
1515 }
1516 #endif
1517 return next_level;
1518 }
1519
1520 // Determine if we should do an OSR compilation of a given method.
1521 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1522 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1523 if (cur_level == CompLevel_none) {
1524 // If there is a live OSR method that means that we deopted to the interpreter
1525 // for the transition.
1526 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1527 if (osr_level > CompLevel_none) {
1528 return osr_level;
1529 }
1530 }
1531 return next_level;
1532 }
1533
1534 // Handle the invocation event.
1535 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1536 CompLevel level, nmethod* nm, TRAPS) {
1537 if (should_create_mdo(mh, level)) {
1538 create_mdo(mh, THREAD);
1539 }
1540 CompLevel next_level = call_event(mh, level, THREAD);
1541 if (next_level != level) {
1542 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1543 compile(mh, InvocationEntryBci, next_level, THREAD);
1544 }
1545 }
1546 }
1547
1548 // Handle the back branch event. Notice that we can compile the method
1549 // with a regular entry from here.
1550 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1551 int bci, CompLevel level, nmethod* nm, TRAPS) {
1552 if (should_create_mdo(mh, level)) {
1553 create_mdo(mh, THREAD);
1554 }
1555 // Check if MDO should be created for the inlined method
1556 if (should_create_mdo(imh, level)) {
1557 create_mdo(imh, THREAD);
1558 }
1559
1560 if (is_compilation_enabled()) {
1561 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1562 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1563 // At the very least compile the OSR version
1564 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1565 compile(imh, bci, next_osr_level, CHECK);
1566 }
1567
1568 // Use loop event as an opportunity to also check if there's been
1569 // enough calls.
1570 CompLevel cur_level, next_level;
1571 if (mh() != imh()) { // If there is an enclosing method
1572 {
1573 guarantee(nm != nullptr, "Should have nmethod here");
1574 cur_level = comp_level(mh());
1575 next_level = call_event(mh, cur_level, THREAD);
1576
1577 if (max_osr_level == CompLevel_full_optimization) {
1578 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1579 bool make_not_entrant = false;
1580 if (nm->is_osr_method()) {
1581 // This is an osr method, just make it not entrant and recompile later if needed
1582 make_not_entrant = true;
1583 } else {
1584 if (next_level != CompLevel_full_optimization) {
1585 // next_level is not full opt, so we need to recompile the
1586 // enclosing method without the inlinee
1587 cur_level = CompLevel_none;
1588 make_not_entrant = true;
1589 }
1590 }
1591 if (make_not_entrant) {
1592 if (PrintTieredEvents) {
1593 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1594 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1595 }
1596 nm->make_not_entrant("OSR invalidation, back branch");
1597 }
1598 }
1599 // Fix up next_level if necessary to avoid deopts
1600 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1601 next_level = CompLevel_full_profile;
1602 }
1603 if (cur_level != next_level) {
1604 if (!CompileBroker::compilation_is_in_queue(mh)) {
1605 compile(mh, InvocationEntryBci, next_level, THREAD);
1606 }
1607 }
1608 }
1609 } else {
1610 cur_level = comp_level(mh());
1611 next_level = call_event(mh, cur_level, THREAD);
1612 if (next_level != cur_level) {
1613 if (!CompileBroker::compilation_is_in_queue(mh)) {
1614 compile(mh, InvocationEntryBci, next_level, THREAD);
1615 }
1616 }
1617 }
1618 }
1619 }
1620