1 /*
2 * Copyright (c) 2010, 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 #include "precompiled.hpp"
26 #include "cds/aotLinkedClassBulkLoader.hpp"
27 #include "code/scopeDesc.hpp"
28 #include "code/SCCache.hpp"
29 #include "compiler/compilationPolicy.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "compiler/compilerDefinitions.inline.hpp"
32 #include "compiler/compilerOracle.hpp"
33 #include "compiler/recompilationPolicy.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "oops/methodData.hpp"
36 #include "oops/method.inline.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "oops/trainingData.hpp"
39 #include "prims/jvmtiExport.hpp"
40 #include "runtime/arguments.hpp"
41 #include "runtime/deoptimization.hpp"
42 #include "runtime/frame.hpp"
43 #include "runtime/frame.inline.hpp"
44 #include "runtime/globals_extension.hpp"
45 #include "runtime/handles.inline.hpp"
46 #include "runtime/safepoint.hpp"
47 #include "runtime/safepointVerifiers.hpp"
48 #ifdef COMPILER1
49 #include "c1/c1_Compiler.hpp"
50 #endif
51 #ifdef COMPILER2
52 #include "opto/c2compiler.hpp"
53 #endif
54 #if INCLUDE_JVMCI
55 #include "jvmci/jvmci.hpp"
56 #endif
57
58 int64_t CompilationPolicy::_start_time = 0;
59 int CompilationPolicy::_c1_count = 0;
60 int CompilationPolicy::_c2_count = 0;
61 int CompilationPolicy::_c3_count = 0;
62 int CompilationPolicy::_sc_count = 0;
63 double CompilationPolicy::_increase_threshold_at_ratio = 0;
64
65 CompilationPolicy::TrainingReplayQueue CompilationPolicy::_training_replay_queue;
66
67 void compilationPolicy_init() {
68 CompilationPolicy::initialize();
69 }
70
71 int CompilationPolicy::compiler_count(CompLevel comp_level) {
72 if (is_c1_compile(comp_level)) {
73 return c1_count();
74 } else if (is_c2_compile(comp_level)) {
75 return c2_count();
76 }
77 return 0;
78 }
79
80 // Returns true if m must be compiled before executing it
81 // This is intended to force compiles for methods (usually for
82 // debugging) that would otherwise be interpreted for some reason.
83 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) {
84 // Don't allow Xcomp to cause compiles in replay mode
85 if (ReplayCompiles) return false;
86
87 if (m->has_compiled_code()) return false; // already compiled
88 if (!can_be_compiled(m, comp_level)) return false;
89
90 return !UseInterpreter || // must compile all methods
91 (AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods
92 }
93
94 void CompilationPolicy::maybe_compile_early(const methodHandle& m, TRAPS) {
95 if (m->method_holder()->is_not_initialized()) {
96 // 'is_not_initialized' means not only '!is_initialized', but also that
97 // initialization has not been started yet ('!being_initialized')
98 // Do not force compilation of methods in uninitialized classes.
99 return;
100 }
101 if (!m->is_native() && MethodTrainingData::have_data()) {
102 MethodTrainingData* mtd = MethodTrainingData::find(m);
103 if (mtd == nullptr) {
104 return; // there is no training data recorded for m
105 }
106 bool recompile = m->code_has_clinit_barriers();
107 CompLevel cur_level = static_cast<CompLevel>(m->highest_comp_level());
108 CompLevel next_level = trained_transition(m, cur_level, mtd, THREAD);
109 if ((next_level != cur_level || recompile) && can_be_compiled(m, next_level) && !CompileBroker::compilation_is_in_queue(m)) {
110 bool requires_online_compilation = false;
111 CompileTrainingData* ctd = mtd->last_toplevel_compile(next_level);
112 if (ctd != nullptr) {
113 requires_online_compilation = (ctd->init_deps_left() > 0);
114 }
115 if (requires_online_compilation && recompile) {
116 return;
117 }
118 if (PrintTieredEvents) {
119 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, next_level);
120 }
121 CompileBroker::compile_method(m, InvocationEntryBci, next_level, methodHandle(), 0, requires_online_compilation, CompileTask::Reason_MustBeCompiled, THREAD);
122 if (HAS_PENDING_EXCEPTION) {
123 CLEAR_PENDING_EXCEPTION;
124 }
125 }
126 }
127 }
128
129 void CompilationPolicy::maybe_compile_early_after_init(const methodHandle& m, TRAPS) {
130 assert(m->method_holder()->is_initialized(), "Should be called after class initialization");
131 maybe_compile_early(m, THREAD);
132 }
133
134 void CompilationPolicy::compile_if_required(const methodHandle& m, TRAPS) {
135 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) {
136 // don't force compilation, resolve was on behalf of compiler
137 return;
138 }
139 if (m->method_holder()->is_not_initialized()) {
140 // 'is_not_initialized' means not only '!is_initialized', but also that
141 // initialization has not been started yet ('!being_initialized')
142 // Do not force compilation of methods in uninitialized classes.
143 // Note that doing this would throw an assert later,
144 // in CompileBroker::compile_method.
145 // We sometimes use the link resolver to do reflective lookups
146 // even before classes are initialized.
147 return;
148 }
149
150 if (must_be_compiled(m)) {
151 // This path is unusual, mostly used by the '-Xcomp' stress test mode.
152 CompLevel level = initial_compile_level(m);
153 if (PrintTieredEvents) {
154 print_event(FORCE_COMPILE, m(), m(), InvocationEntryBci, level);
155 }
156 CompileBroker::compile_method(m, InvocationEntryBci, level, methodHandle(), 0, false, CompileTask::Reason_MustBeCompiled, THREAD);
157 }
158 }
159
160 void CompilationPolicy::replay_training_at_init_impl(InstanceKlass* klass, TRAPS) {
161 if (!klass->has_init_deps_processed()) {
162 ResourceMark rm;
163 log_debug(training)("Replay training: %s", klass->external_name());
164
165 KlassTrainingData* ktd = KlassTrainingData::find(klass);
166 if (ktd != nullptr) {
167 guarantee(ktd->has_holder(), "");
168 ktd->notice_fully_initialized(); // sets klass->has_init_deps_processed bit
169 assert(klass->has_init_deps_processed(), "");
170
171 ktd->iterate_all_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 Array<Method*>* methods = klass->methods();
182 for (int i = 0; i < methods->length(); i++) {
183 const methodHandle mh(THREAD, methods->at(i));
184 CompilationPolicy::maybe_compile_early_after_init(mh, THREAD);
185 }
186 }
187 }
188
189 void CompilationPolicy::replay_training_at_init(bool is_on_shutdown, TRAPS) {
190 // Drain pending queue when no concurrent processing thread is present.
191 if (UseConcurrentTrainingReplay) {
192 if (VerifyTrainingData) {
193 MonitorLocker locker(THREAD, TrainingReplayQueue_lock);
194 while (!_training_replay_queue.is_empty_unlocked()) {
195 locker.wait(); // let the replay training thread drain the queue
196 }
197 }
198 } else {
199 do {
200 InstanceKlass* pending = _training_replay_queue.try_pop(TrainingReplayQueue_lock, THREAD);
201 if (pending == nullptr) {
202 break; // drained the queue
203 }
204 if (is_on_shutdown) {
205 LogStreamHandle(Warning, training) log;
206 if (log.is_enabled()) {
207 ResourceMark rm;
208 log.print("pending training replay request: %s%s",
209 pending->external_name(), (pending->has_aot_initialized_mirror() ? " (preinitialized)" : ""));
210 }
211 }
212 replay_training_at_init_impl(pending, THREAD);
213 } while (true);
214 }
215
216 if (VerifyTrainingData) {
217 TrainingData::verify();
218 }
219 }
220
221 void CompilationPolicy::replay_training_at_init(InstanceKlass* klass, TRAPS) {
222 assert(klass->is_initialized(), "");
223 if (TrainingData::have_data() && klass->is_shared() &&
224 (CompileBroker::replay_initialized() || !klass->has_aot_initialized_mirror())) { // ignore preloaded classes during early startup
225 if (UseConcurrentTrainingReplay || !CompileBroker::replay_initialized()) {
226 _training_replay_queue.push(klass, TrainingReplayQueue_lock, THREAD);
227 } else {
228 replay_training_at_init_impl(klass, THREAD);
229 }
230 assert(!HAS_PENDING_EXCEPTION, "");
231 }
232 }
233
234 // For TrainingReplayQueue
235 template<>
236 void CompilationPolicyUtils::Queue<InstanceKlass>::print_on(outputStream* st) {
237 int pos = 0;
238 for (QueueNode* cur = _head; cur != nullptr; cur = cur->next()) {
239 ResourceMark rm;
240 InstanceKlass* ik = cur->value();
241 st->print_cr("%3d: " INTPTR_FORMAT " %s", ++pos, p2i(ik), ik->external_name());
242 }
243 }
244
245 void CompilationPolicy::replay_training_at_init_loop(TRAPS) {
246 precond(UseConcurrentTrainingReplay);
247
248 while (!CompileBroker::is_compilation_disabled_forever() || VerifyTrainingData) {
249 InstanceKlass* ik = _training_replay_queue.pop(TrainingReplayQueue_lock, THREAD);
250 replay_training_at_init_impl(ik, THREAD);
251 }
252 }
253
254 static inline CompLevel adjust_level_for_compilability_query(CompLevel comp_level) {
255 if (comp_level == CompLevel_any) {
256 if (CompilerConfig::is_c1_only()) {
257 comp_level = CompLevel_simple;
258 } else if (CompilerConfig::is_c2_or_jvmci_compiler_only()) {
259 comp_level = CompLevel_full_optimization;
260 }
261 }
262 return comp_level;
263 }
264
265 // Returns true if m is allowed to be compiled
266 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) {
267 // allow any levels for WhiteBox
268 assert(WhiteBoxAPI || comp_level == CompLevel_any || is_compile(comp_level), "illegal compilation level %d", comp_level);
269
270 if (m->is_abstract()) return false;
271 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false;
272
273 // Math intrinsics should never be compiled as this can lead to
274 // monotonicity problems because the interpreter will prefer the
275 // compiled code to the intrinsic version. This can't happen in
276 // production because the invocation counter can't be incremented
277 // but we shouldn't expose the system to this problem in testing
278 // modes.
279 if (!AbstractInterpreter::can_be_compiled(m)) {
280 return false;
281 }
282 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
283 if (comp_level == CompLevel_any || is_compile(comp_level)) {
284 return !m->is_not_compilable(comp_level);
285 }
286 return false;
287 }
288
289 // Returns true if m is allowed to be osr compiled
290 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) {
291 bool result = false;
292 comp_level = adjust_level_for_compilability_query((CompLevel) comp_level);
293 if (comp_level == CompLevel_any || is_compile(comp_level)) {
294 result = !m->is_not_osr_compilable(comp_level);
295 }
296 return (result && can_be_compiled(m, comp_level));
297 }
298
299 bool CompilationPolicy::is_compilation_enabled() {
300 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler
301 return CompileBroker::should_compile_new_jobs();
302 }
303
304 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) {
305 // Remove unloaded methods from the queue
306 for (CompileTask* task = compile_queue->first(); task != nullptr; ) {
307 CompileTask* next = task->next();
308 if (task->is_unloaded()) {
309 compile_queue->remove_and_mark_stale(task);
310 }
311 task = next;
312 }
313 #if INCLUDE_JVMCI
314 if (UseJVMCICompiler && !BackgroundCompilation) {
315 /*
316 * In blocking compilation mode, the CompileBroker will make
317 * compilations submitted by a JVMCI compiler thread non-blocking. These
318 * compilations should be scheduled after all blocking compilations
319 * to service non-compiler related compilations sooner and reduce the
320 * chance of such compilations timing out.
321 */
322 for (CompileTask* task = compile_queue->first(); task != nullptr; task = task->next()) {
323 if (task->is_blocking()) {
324 return task;
325 }
326 }
327 }
328 #endif
329 return compile_queue->first();
330 }
331
332 // Simple methods are as good being compiled with C1 as C2.
333 // Determine if a given method is such a case.
334 bool CompilationPolicy::is_trivial(const methodHandle& method) {
335 if (method->is_accessor() ||
336 method->is_constant_getter()) {
337 return true;
338 }
339 return false;
340 }
341
342 bool CompilationPolicy::force_comp_at_level_simple(const methodHandle& method) {
343 if (CompilationModeFlag::quick_internal()) {
344 #if INCLUDE_JVMCI
345 if (UseJVMCICompiler) {
346 AbstractCompiler* comp = CompileBroker::compiler(CompLevel_full_optimization);
347 if (comp != nullptr && comp->is_jvmci() && ((JVMCICompiler*) comp)->force_comp_at_level_simple(method)) {
348 return !SCCache::is_C3_on();
349 }
350 }
351 #endif
352 }
353 return false;
354 }
355
356 CompLevel CompilationPolicy::comp_level(Method* method) {
357 nmethod *nm = method->code();
358 if (nm != nullptr && nm->is_in_use()) {
359 return (CompLevel)nm->comp_level();
360 }
361 return CompLevel_none;
362 }
363
364 // Call and loop predicates determine whether a transition to a higher
365 // compilation level should be performed (pointers to predicate functions
366 // are passed to common()).
367 // Tier?LoadFeedback is basically a coefficient that determines of
368 // how many methods per compiler thread can be in the queue before
369 // the threshold values double.
370 class LoopPredicate : AllStatic {
371 public:
372 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
373 double threshold_scaling;
374 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
375 scale *= threshold_scaling;
376 }
377 switch(cur_level) {
378 case CompLevel_none:
379 case CompLevel_limited_profile:
380 return b >= Tier3BackEdgeThreshold * scale;
381 case CompLevel_full_profile:
382 return b >= Tier4BackEdgeThreshold * scale;
383 default:
384 return true;
385 }
386 }
387
388 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
389 double k = 1;
390 switch(cur_level) {
391 case CompLevel_none:
392 // Fall through
393 case CompLevel_limited_profile: {
394 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
395 break;
396 }
397 case CompLevel_full_profile: {
398 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
399 break;
400 }
401 default:
402 return true;
403 }
404 return apply_scaled(method, cur_level, i, b, k);
405 }
406 };
407
408 class CallPredicate : AllStatic {
409 public:
410 static bool apply_scaled(const methodHandle& method, CompLevel cur_level, int i, int b, double scale) {
411 double threshold_scaling;
412 if (CompilerOracle::has_option_value(method, CompileCommandEnum::CompileThresholdScaling, threshold_scaling)) {
413 scale *= threshold_scaling;
414 }
415 switch(cur_level) {
416 case CompLevel_none:
417 case CompLevel_limited_profile:
418 return (i >= Tier3InvocationThreshold * scale) ||
419 (i >= Tier3MinInvocationThreshold * scale && i + b >= Tier3CompileThreshold * scale);
420 case CompLevel_full_profile:
421 return (i >= Tier4InvocationThreshold * scale) ||
422 (i >= Tier4MinInvocationThreshold * scale && i + b >= Tier4CompileThreshold * scale);
423 default:
424 return true;
425 }
426 }
427
428 static bool apply(const methodHandle& method, CompLevel cur_level, int i, int b) {
429 double k = 1;
430 switch(cur_level) {
431 case CompLevel_none:
432 case CompLevel_limited_profile: {
433 k = CompilationPolicy::threshold_scale(CompLevel_full_profile, Tier3LoadFeedback);
434 break;
435 }
436 case CompLevel_full_profile: {
437 k = CompilationPolicy::threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback);
438 break;
439 }
440 default:
441 return true;
442 }
443 return apply_scaled(method, cur_level, i, b, k);
444 }
445 };
446
447 double CompilationPolicy::threshold_scale(CompLevel level, int feedback_k) {
448 int comp_count = compiler_count(level);
449 if (comp_count > 0) {
450 double queue_size = CompileBroker::queue_size(level);
451 double k = (double)queue_size / ((double)feedback_k * (double)comp_count) + 1;
452
453 // Increase C1 compile threshold when the code cache is filled more
454 // than specified by IncreaseFirstTierCompileThresholdAt percentage.
455 // The main intention is to keep enough free space for C2 compiled code
456 // to achieve peak performance if the code cache is under stress.
457 if (CompilerConfig::is_tiered() && !CompilationModeFlag::disable_intermediate() && is_c1_compile(level)) {
458 double current_reverse_free_ratio = CodeCache::reverse_free_ratio();
459 if (current_reverse_free_ratio > _increase_threshold_at_ratio) {
460 k *= exp(current_reverse_free_ratio - _increase_threshold_at_ratio);
461 }
462 }
463 return k;
464 }
465 return 1;
466 }
467
468 void CompilationPolicy::print_counters(const char* prefix, Method* m) {
469 int invocation_count = m->invocation_count();
470 int backedge_count = m->backedge_count();
471 MethodData* mdh = m->method_data();
472 int mdo_invocations = 0, mdo_backedges = 0;
473 int mdo_invocations_start = 0, mdo_backedges_start = 0;
474 if (mdh != nullptr) {
475 mdo_invocations = mdh->invocation_count();
476 mdo_backedges = mdh->backedge_count();
477 mdo_invocations_start = mdh->invocation_count_start();
478 mdo_backedges_start = mdh->backedge_count_start();
479 }
480 tty->print(" %stotal=%d,%d %smdo=%d(%d),%d(%d)", prefix,
481 invocation_count, backedge_count, prefix,
482 mdo_invocations, mdo_invocations_start,
483 mdo_backedges, mdo_backedges_start);
484 tty->print(" %smax levels=%d,%d", prefix,
485 m->highest_comp_level(), m->highest_osr_comp_level());
486 }
487
488 void CompilationPolicy::print_training_data(const char* prefix, Method* method) {
489 methodHandle m(Thread::current(), method);
490 tty->print(" %smtd: ", prefix);
491 MethodTrainingData* mtd = MethodTrainingData::find(m);
492 if (mtd == nullptr) {
493 tty->print("null");
494 } else {
495 MethodData* md = mtd->final_profile();
496 tty->print("mdo=");
497 if (md == nullptr) {
498 tty->print("null");
499 } else {
500 int mdo_invocations = md->invocation_count();
501 int mdo_backedges = md->backedge_count();
502 int mdo_invocations_start = md->invocation_count_start();
503 int mdo_backedges_start = md->backedge_count_start();
504 tty->print("%d(%d), %d(%d)", mdo_invocations, mdo_invocations_start, mdo_backedges, mdo_backedges_start);
505 }
506 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
507 tty->print(", deps=");
508 if (ctd == nullptr) {
509 tty->print("null");
510 } else {
511 tty->print("%d", ctd->init_deps_left());
512 }
513 }
514 }
515
516 // Print an event.
517 void CompilationPolicy::print_event(EventType type, Method* m, Method* im, int bci, CompLevel level) {
518 bool inlinee_event = m != im;
519
520 ttyLocker tty_lock;
521 tty->print("%lf: [", os::elapsedTime());
522
523 switch(type) {
524 case CALL:
525 tty->print("call");
526 break;
527 case LOOP:
528 tty->print("loop");
529 break;
530 case COMPILE:
531 tty->print("compile");
532 break;
533 case FORCE_COMPILE:
534 tty->print("force-compile");
535 break;
536 case FORCE_RECOMPILE:
537 tty->print("force-recompile");
538 break;
539 case REMOVE_FROM_QUEUE:
540 tty->print("remove-from-queue");
541 break;
542 case UPDATE_IN_QUEUE:
543 tty->print("update-in-queue");
544 break;
545 case REPROFILE:
546 tty->print("reprofile");
547 break;
548 case MAKE_NOT_ENTRANT:
549 tty->print("make-not-entrant");
550 break;
551 default:
552 tty->print("unknown");
553 }
554
555 tty->print(" level=%d ", level);
556
557 ResourceMark rm;
558 char *method_name = m->name_and_sig_as_C_string();
559 tty->print("[%s", method_name);
560 if (inlinee_event) {
561 char *inlinee_name = im->name_and_sig_as_C_string();
562 tty->print(" [%s]] ", inlinee_name);
563 }
564 else tty->print("] ");
565 tty->print("@%d queues=%d,%d", bci, CompileBroker::queue_size(CompLevel_full_profile),
566 CompileBroker::queue_size(CompLevel_full_optimization));
567
568 tty->print(" rate=");
569 if (m->prev_time() == 0) tty->print("n/a");
570 else tty->print("%f", m->rate());
571
572 RecompilationPolicy::print_load_average();
573
574 tty->print(" k=%.2lf,%.2lf", threshold_scale(CompLevel_full_profile, Tier3LoadFeedback),
575 threshold_scale(CompLevel_full_optimization, Tier4LoadFeedback));
576
577 if (type != COMPILE) {
578 print_counters("", m);
579 if (inlinee_event) {
580 print_counters("inlinee ", im);
581 }
582 tty->print(" compilable=");
583 bool need_comma = false;
584 if (!m->is_not_compilable(CompLevel_full_profile)) {
585 tty->print("c1");
586 need_comma = true;
587 }
588 if (!m->is_not_osr_compilable(CompLevel_full_profile)) {
589 if (need_comma) tty->print(",");
590 tty->print("c1-osr");
591 need_comma = true;
592 }
593 if (!m->is_not_compilable(CompLevel_full_optimization)) {
594 if (need_comma) tty->print(",");
595 tty->print("c2");
596 need_comma = true;
597 }
598 if (!m->is_not_osr_compilable(CompLevel_full_optimization)) {
599 if (need_comma) tty->print(",");
600 tty->print("c2-osr");
601 }
602 tty->print(" status=");
603 if (m->queued_for_compilation()) {
604 tty->print("in-queue");
605 } else tty->print("idle");
606 print_training_data("", m);
607 if (inlinee_event) {
608 print_training_data("inlinee ", im);
609 }
610 }
611 tty->print_cr("]");
612 }
613
614 void CompilationPolicy::initialize() {
615 if (!CompilerConfig::is_interpreter_only()) {
616 int count = CICompilerCount;
617 bool c1_only = CompilerConfig::is_c1_only();
618 bool c2_only = CompilerConfig::is_c2_or_jvmci_compiler_only();
619
620 #ifdef _LP64
621 // Turn on ergonomic compiler count selection
622 if (FLAG_IS_DEFAULT(CICompilerCountPerCPU) && FLAG_IS_DEFAULT(CICompilerCount)) {
623 FLAG_SET_DEFAULT(CICompilerCountPerCPU, true);
624 }
625 if (CICompilerCountPerCPU) {
626 // Simple log n seems to grow too slowly for tiered, try something faster: log n * log log n
627 int log_cpu = log2i(os::active_processor_count());
628 int loglog_cpu = log2i(MAX2(log_cpu, 1));
629 count = MAX2(log_cpu * loglog_cpu * 3 / 2, 2);
630 // Make sure there is enough space in the code cache to hold all the compiler buffers
631 size_t c1_size = 0;
632 #ifdef COMPILER1
633 c1_size = Compiler::code_buffer_size();
634 #endif
635 size_t c2_size = 0;
636 #ifdef COMPILER2
637 c2_size = C2Compiler::initial_code_buffer_size();
638 #endif
639 size_t buffer_size = c1_only ? c1_size : (c1_size/3 + 2*c2_size/3);
640 int max_count = (ReservedCodeCacheSize - (int)CompilerConfig::min_code_cache_size()) / (int)buffer_size;
641 if (count > max_count) {
642 // Lower the compiler count such that all buffers fit into the code cache
643 count = MAX2(max_count, c1_only ? 1 : 2);
644 }
645 FLAG_SET_ERGO(CICompilerCount, count);
646 }
647 #else
648 // On 32-bit systems, the number of compiler threads is limited to 3.
649 // On these systems, the virtual address space available to the JVM
650 // is usually limited to 2-4 GB (the exact value depends on the platform).
651 // As the compilers (especially C2) can consume a large amount of
652 // memory, scaling the number of compiler threads with the number of
653 // available cores can result in the exhaustion of the address space
654 /// available to the VM and thus cause the VM to crash.
655 if (FLAG_IS_DEFAULT(CICompilerCount)) {
656 count = 3;
657 FLAG_SET_ERGO(CICompilerCount, count);
658 }
659 #endif
660
661 if (c1_only) {
662 // No C2 compiler thread required
663 set_c1_count(count);
664 } else if (c2_only) {
665 set_c2_count(count);
666 } else {
667 #if INCLUDE_JVMCI
668 if (UseJVMCICompiler && UseJVMCINativeLibrary) {
669 int libjvmci_count = MAX2((int) (count * JVMCINativeLibraryThreadFraction), 1);
670 int c1_count = MAX2(count - libjvmci_count, 1);
671 set_c2_count(libjvmci_count);
672 set_c1_count(c1_count);
673 } else if (SCCache::is_C3_on()) {
674 set_c1_count(MAX2(count / 3, 1));
675 set_c2_count(MAX2(count - c1_count(), 1));
676 set_c3_count(1);
677 } else
678 #endif
679 {
680 set_c1_count(MAX2(count / 3, 1));
681 set_c2_count(MAX2(count - c1_count(), 1));
682 }
683 }
684 if (SCCache::is_code_load_thread_on()) {
685 set_sc_count((c1_only || c2_only) ? 1 : 2); // At minimum we need 2 threads to load C1 and C2 cached code in parallel
686 }
687 assert(count == c1_count() + c2_count(), "inconsistent compiler thread count");
688 set_increase_threshold_at_ratio();
689 }
690
691 set_start_time(nanos_to_millis(os::javaTimeNanos()));
692 }
693
694
695
696
697 #ifdef ASSERT
698 bool CompilationPolicy::verify_level(CompLevel level) {
699 if (TieredCompilation && level > TieredStopAtLevel) {
700 return false;
701 }
702 // Check if there is a compiler to process the requested level
703 if (!CompilerConfig::is_c1_enabled() && is_c1_compile(level)) {
704 return false;
705 }
706 if (!CompilerConfig::is_c2_or_jvmci_compiler_enabled() && is_c2_compile(level)) {
707 return false;
708 }
709
710 // Interpreter level is always valid.
711 if (level == CompLevel_none) {
712 return true;
713 }
714 if (CompilationModeFlag::normal()) {
715 return true;
716 } else if (CompilationModeFlag::quick_only()) {
717 return level == CompLevel_simple;
718 } else if (CompilationModeFlag::high_only()) {
719 return level == CompLevel_full_optimization;
720 } else if (CompilationModeFlag::high_only_quick_internal()) {
721 return level == CompLevel_full_optimization || level == CompLevel_simple;
722 }
723 return false;
724 }
725 #endif
726
727
728 CompLevel CompilationPolicy::highest_compile_level() {
729 CompLevel level = CompLevel_none;
730 // Setup the maximum level available for the current compiler configuration.
731 if (!CompilerConfig::is_interpreter_only()) {
732 if (CompilerConfig::is_c2_or_jvmci_compiler_enabled()) {
733 level = CompLevel_full_optimization;
734 } else if (CompilerConfig::is_c1_enabled()) {
735 if (CompilerConfig::is_c1_simple_only()) {
736 level = CompLevel_simple;
737 } else {
738 level = CompLevel_full_profile;
739 }
740 }
741 }
742 // Clamp the maximum level with TieredStopAtLevel.
743 if (TieredCompilation) {
744 level = MIN2(level, (CompLevel) TieredStopAtLevel);
745 }
746
747 // Fix it up if after the clamping it has become invalid.
748 // Bring it monotonically down depending on the next available level for
749 // the compilation mode.
750 if (!CompilationModeFlag::normal()) {
751 // a) quick_only - levels 2,3,4 are invalid; levels -1,0,1 are valid;
752 // b) high_only - levels 1,2,3 are invalid; levels -1,0,4 are valid;
753 // c) high_only_quick_internal - levels 2,3 are invalid; levels -1,0,1,4 are valid.
754 if (CompilationModeFlag::quick_only()) {
755 if (level == CompLevel_limited_profile || level == CompLevel_full_profile || level == CompLevel_full_optimization) {
756 level = CompLevel_simple;
757 }
758 } else if (CompilationModeFlag::high_only()) {
759 if (level == CompLevel_simple || level == CompLevel_limited_profile || level == CompLevel_full_profile) {
760 level = CompLevel_none;
761 }
762 } else if (CompilationModeFlag::high_only_quick_internal()) {
763 if (level == CompLevel_limited_profile || level == CompLevel_full_profile) {
764 level = CompLevel_simple;
765 }
766 }
767 }
768
769 assert(verify_level(level), "Invalid highest compilation level: %d", level);
770 return level;
771 }
772
773 CompLevel CompilationPolicy::limit_level(CompLevel level) {
774 level = MIN2(level, highest_compile_level());
775 assert(verify_level(level), "Invalid compilation level: %d", level);
776 return level;
777 }
778
779 CompLevel CompilationPolicy::initial_compile_level(const methodHandle& method) {
780 CompLevel level = CompLevel_any;
781 if (CompilationModeFlag::normal()) {
782 level = CompLevel_full_profile;
783 } else if (CompilationModeFlag::quick_only()) {
784 level = CompLevel_simple;
785 } else if (CompilationModeFlag::high_only()) {
786 level = CompLevel_full_optimization;
787 } else if (CompilationModeFlag::high_only_quick_internal()) {
788 if (force_comp_at_level_simple(method)) {
789 level = CompLevel_simple;
790 } else {
791 level = CompLevel_full_optimization;
792 }
793 }
794 assert(level != CompLevel_any, "Unhandled compilation mode");
795 return limit_level(level);
796 }
797
798 // Set carry flags on the counters if necessary
799 void CompilationPolicy::handle_counter_overflow(const methodHandle& method) {
800 MethodCounters *mcs = method->method_counters();
801 if (mcs != nullptr) {
802 mcs->invocation_counter()->set_carry_on_overflow();
803 mcs->backedge_counter()->set_carry_on_overflow();
804 }
805 MethodData* mdo = method->method_data();
806 if (mdo != nullptr) {
807 mdo->invocation_counter()->set_carry_on_overflow();
808 mdo->backedge_counter()->set_carry_on_overflow();
809 }
810 }
811
812 // Called with the queue locked and with at least one element
813 CompileTask* CompilationPolicy::select_task(CompileQueue* compile_queue, JavaThread* THREAD) {
814 CompileTask *max_blocking_task = nullptr;
815 CompileTask *max_task = nullptr;
816 Method* max_method = nullptr;
817
818 int64_t t = nanos_to_millis(os::javaTimeNanos());
819 // Iterate through the queue and find a method with a maximum rate.
820 for (CompileTask* task = compile_queue->first(); task != nullptr;) {
821 CompileTask* next_task = task->next();
822 // If a method was unloaded or has been stale for some time, remove it from the queue.
823 // Blocking tasks and tasks submitted from whitebox API don't become stale
824 if (task->is_unloaded()) {
825 compile_queue->remove_and_mark_stale(task);
826 task = next_task;
827 continue;
828 }
829 if (task->is_scc()) {
830 // SCC tasks are on separate queue, and they should load fast. There is no need to walk
831 // the rest of the queue, just take the task and go.
832 return task;
833 }
834 Method* method = task->method();
835 methodHandle mh(THREAD, method);
836 if (task->can_become_stale() && is_stale(t, TieredCompileTaskTimeout, mh) && !is_old(mh)) {
837 if (PrintTieredEvents) {
838 print_event(REMOVE_FROM_QUEUE, method, method, task->osr_bci(), (CompLevel) task->comp_level());
839 }
840 method->clear_queued_for_compilation();
841 method->set_pending_queue_processed(false);
842 compile_queue->remove_and_mark_stale(task);
843 task = next_task;
844 continue;
845 }
846 update_rate(t, mh);
847 if (max_task == nullptr || compare_methods(method, max_method) || compare_tasks(task, max_task)) {
848 // Select a method with the highest rate
849 max_task = task;
850 max_method = method;
851 }
852
853 if (task->is_blocking()) {
854 if (max_blocking_task == nullptr || compare_methods(method, max_blocking_task->method())) {
855 max_blocking_task = task;
856 }
857 }
858
859 task = next_task;
860 }
861
862 if (max_blocking_task != nullptr) {
863 // In blocking compilation mode, the CompileBroker will make
864 // compilations submitted by a JVMCI compiler thread non-blocking. These
865 // compilations should be scheduled after all blocking compilations
866 // to service non-compiler related compilations sooner and reduce the
867 // chance of such compilations timing out.
868 max_task = max_blocking_task;
869 max_method = max_task->method();
870 }
871
872 methodHandle max_method_h(THREAD, max_method);
873
874 if (max_task != nullptr && max_task->comp_level() == CompLevel_full_profile && TieredStopAtLevel > CompLevel_full_profile &&
875 max_method != nullptr && is_method_profiled(max_method_h) && !Arguments::is_compiler_only()) {
876 max_task->set_comp_level(CompLevel_limited_profile);
877
878 if (CompileBroker::compilation_is_complete(max_method_h(), max_task->osr_bci(), CompLevel_limited_profile,
879 false /* requires_online_compilation */,
880 CompileTask::Reason_None)) {
881 if (PrintTieredEvents) {
882 print_event(REMOVE_FROM_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
883 }
884 compile_queue->remove_and_mark_stale(max_task);
885 max_method->clear_queued_for_compilation();
886 return nullptr;
887 }
888
889 if (PrintTieredEvents) {
890 print_event(UPDATE_IN_QUEUE, max_method, max_method, max_task->osr_bci(), (CompLevel)max_task->comp_level());
891 }
892 }
893 return max_task;
894 }
895
896 void CompilationPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) {
897 for (ScopeDesc* sd = trap_scope;; sd = sd->sender()) {
898 if (PrintTieredEvents) {
899 print_event(REPROFILE, sd->method(), sd->method(), InvocationEntryBci, CompLevel_none);
900 }
901 MethodData* mdo = sd->method()->method_data();
902 if (mdo != nullptr) {
903 mdo->reset_start_counters();
904 }
905 if (sd->is_top()) break;
906 }
907 }
908
909 nmethod* CompilationPolicy::event(const methodHandle& method, const methodHandle& inlinee,
910 int branch_bci, int bci, CompLevel comp_level, nmethod* nm, TRAPS) {
911 if (PrintTieredEvents) {
912 print_event(bci == InvocationEntryBci ? CALL : LOOP, method(), inlinee(), bci, comp_level);
913 }
914
915 #if INCLUDE_JVMCI
916 if (EnableJVMCI && UseJVMCICompiler &&
917 comp_level == CompLevel_full_optimization && !AOTLinkedClassBulkLoader::class_preloading_finished()) {
918 return nullptr;
919 }
920 #endif
921
922 if (comp_level == CompLevel_none &&
923 JvmtiExport::can_post_interpreter_events() &&
924 THREAD->is_interp_only_mode()) {
925 return nullptr;
926 }
927 if (ReplayCompiles) {
928 // Don't trigger other compiles in testing mode
929 return nullptr;
930 }
931
932 handle_counter_overflow(method);
933 if (method() != inlinee()) {
934 handle_counter_overflow(inlinee);
935 }
936
937 if (bci == InvocationEntryBci) {
938 method_invocation_event(method, inlinee, comp_level, nm, THREAD);
939 } else {
940 // method == inlinee if the event originated in the main method
941 method_back_branch_event(method, inlinee, bci, comp_level, nm, THREAD);
942 // Check if event led to a higher level OSR compilation
943 CompLevel expected_comp_level = MIN2(CompLevel_full_optimization, static_cast<CompLevel>(comp_level + 1));
944 if (!CompilationModeFlag::disable_intermediate() && inlinee->is_not_osr_compilable(expected_comp_level)) {
945 // It's not possible to reach the expected level so fall back to simple.
946 expected_comp_level = CompLevel_simple;
947 }
948 CompLevel max_osr_level = static_cast<CompLevel>(inlinee->highest_osr_comp_level());
949 if (max_osr_level >= expected_comp_level) { // fast check to avoid locking in a typical scenario
950 nmethod* osr_nm = inlinee->lookup_osr_nmethod_for(bci, expected_comp_level, false);
951 assert(osr_nm == nullptr || osr_nm->comp_level() >= expected_comp_level, "lookup_osr_nmethod_for is broken");
952 if (osr_nm != nullptr && osr_nm->comp_level() != comp_level) {
953 // Perform OSR with new nmethod
954 return osr_nm;
955 }
956 }
957 }
958 return nullptr;
959 }
960
961 // Check if the method can be compiled, change level if necessary
962 void CompilationPolicy::compile(const methodHandle& mh, int bci, CompLevel level, TRAPS) {
963 assert(verify_level(level), "Invalid compilation level requested: %d", level);
964
965 if (level == CompLevel_none) {
966 if (mh->has_compiled_code()) {
967 // Happens when we switch to interpreter to profile.
968 MutexLocker ml(Compile_lock);
969 NoSafepointVerifier nsv;
970 if (mh->has_compiled_code()) {
971 mh->code()->make_not_used();
972 }
973 // Deoptimize immediately (we don't have to wait for a compile).
974 JavaThread* jt = THREAD;
975 RegisterMap map(jt,
976 RegisterMap::UpdateMap::skip,
977 RegisterMap::ProcessFrames::include,
978 RegisterMap::WalkContinuation::skip);
979 frame fr = jt->last_frame().sender(&map);
980 Deoptimization::deoptimize_frame(jt, fr.id());
981 }
982 return;
983 }
984
985 if (!CompilationModeFlag::disable_intermediate()) {
986 // Check if the method can be compiled. If it cannot be compiled with C1, continue profiling
987 // in the interpreter and then compile with C2 (the transition function will request that,
988 // see common() ). If the method cannot be compiled with C2 but still can with C1, compile it with
989 // pure C1.
990 if ((bci == InvocationEntryBci && !can_be_compiled(mh, level))) {
991 if (level == CompLevel_full_optimization && can_be_compiled(mh, CompLevel_simple)) {
992 compile(mh, bci, CompLevel_simple, THREAD);
993 }
994 return;
995 }
996 if ((bci != InvocationEntryBci && !can_be_osr_compiled(mh, level))) {
997 if (level == CompLevel_full_optimization && can_be_osr_compiled(mh, CompLevel_simple)) {
998 nmethod* osr_nm = mh->lookup_osr_nmethod_for(bci, CompLevel_simple, false);
999 if (osr_nm != nullptr && osr_nm->comp_level() > CompLevel_simple) {
1000 // Invalidate the existing OSR nmethod so that a compile at CompLevel_simple is permitted.
1001 osr_nm->make_not_entrant();
1002 }
1003 compile(mh, bci, CompLevel_simple, THREAD);
1004 }
1005 return;
1006 }
1007 }
1008 if (bci != InvocationEntryBci && mh->is_not_osr_compilable(level)) {
1009 return;
1010 }
1011 if (!CompileBroker::compilation_is_in_queue(mh)) {
1012 if (PrintTieredEvents) {
1013 print_event(COMPILE, mh(), mh(), bci, level);
1014 }
1015 int hot_count = (bci == InvocationEntryBci) ? mh->invocation_count() : mh->backedge_count();
1016 update_rate(nanos_to_millis(os::javaTimeNanos()), mh);
1017 bool requires_online_compilation = false;
1018 if (TrainingData::have_data()) {
1019 MethodTrainingData* mtd = MethodTrainingData::find(mh);
1020 if (mtd != nullptr) {
1021 CompileTrainingData* ctd = mtd->last_toplevel_compile(level);
1022 if (ctd != nullptr) {
1023 requires_online_compilation = (ctd->init_deps_left() > 0);
1024 }
1025 }
1026 }
1027 CompileBroker::compile_method(mh, bci, level, mh, hot_count, requires_online_compilation, CompileTask::Reason_Tiered, THREAD);
1028 }
1029 }
1030
1031 // update_rate() is called from select_task() while holding a compile queue lock.
1032 void CompilationPolicy::update_rate(int64_t t, const methodHandle& method) {
1033 // Skip update if counters are absent.
1034 // Can't allocate them since we are holding compile queue lock.
1035 if (method->method_counters() == nullptr) return;
1036
1037 if (is_old(method)) {
1038 // We don't remove old methods from the queue,
1039 // so we can just zero the rate.
1040 method->set_rate(0);
1041 return;
1042 }
1043
1044 // We don't update the rate if we've just came out of a safepoint.
1045 // delta_s is the time since last safepoint in milliseconds.
1046 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1047 int64_t delta_t = t - (method->prev_time() != 0 ? method->prev_time() : start_time()); // milliseconds since the last measurement
1048 // How many events were there since the last time?
1049 int event_count = method->invocation_count() + method->backedge_count();
1050 int delta_e = event_count - method->prev_event_count();
1051
1052 // We should be running for at least 1ms.
1053 if (delta_s >= TieredRateUpdateMinTime) {
1054 // And we must've taken the previous point at least 1ms before.
1055 if (delta_t >= TieredRateUpdateMinTime && delta_e > 0) {
1056 method->set_prev_time(t);
1057 method->set_prev_event_count(event_count);
1058 method->set_rate((float)delta_e / (float)delta_t); // Rate is events per millisecond
1059 } else {
1060 if (delta_t > TieredRateUpdateMaxTime && delta_e == 0) {
1061 // If nothing happened for 25ms, zero the rate. Don't modify prev values.
1062 method->set_rate(0);
1063 }
1064 }
1065 }
1066 }
1067
1068 // Check if this method has been stale for a given number of milliseconds.
1069 // See select_task().
1070 bool CompilationPolicy::is_stale(int64_t t, int64_t timeout, const methodHandle& method) {
1071 int64_t delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
1072 int64_t delta_t = t - method->prev_time();
1073 if (delta_t > timeout && delta_s > timeout) {
1074 int event_count = method->invocation_count() + method->backedge_count();
1075 int delta_e = event_count - method->prev_event_count();
1076 // Return true if there were no events.
1077 return delta_e == 0;
1078 }
1079 return false;
1080 }
1081
1082 // We don't remove old methods from the compile queue even if they have
1083 // very low activity. See select_task().
1084 bool CompilationPolicy::is_old(const methodHandle& method) {
1085 int i = method->invocation_count();
1086 int b = method->backedge_count();
1087 double k = TieredOldPercentage / 100.0;
1088
1089 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1090 }
1091
1092 double CompilationPolicy::weight(Method* method) {
1093 return (double)(method->rate() + 1) * (method->invocation_count() + 1) * (method->backedge_count() + 1);
1094 }
1095
1096 // Apply heuristics and return true if x should be compiled before y
1097 bool CompilationPolicy::compare_methods(Method* x, Method* y) {
1098 if (x->highest_comp_level() > y->highest_comp_level()) {
1099 // recompilation after deopt
1100 return true;
1101 } else
1102 if (x->highest_comp_level() == y->highest_comp_level()) {
1103 if (weight(x) > weight(y)) {
1104 return true;
1105 }
1106 }
1107 return false;
1108 }
1109
1110 bool CompilationPolicy::compare_tasks(CompileTask* x, CompileTask* y) {
1111 assert(!x->is_scc() && !y->is_scc(), "SC tasks are not expected here");
1112 if (x->compile_reason() != y->compile_reason() && y->compile_reason() == CompileTask::Reason_MustBeCompiled) {
1113 return true;
1114 }
1115 return false;
1116 }
1117
1118 // Is method profiled enough?
1119 bool CompilationPolicy::is_method_profiled(const methodHandle& method) {
1120 MethodData* mdo = method->method_data();
1121 if (mdo != nullptr) {
1122 int i = mdo->invocation_count_delta();
1123 int b = mdo->backedge_count_delta();
1124 return CallPredicate::apply_scaled(method, CompLevel_full_profile, i, b, 1);
1125 }
1126 return false;
1127 }
1128
1129
1130 // Determine is a method is mature.
1131 bool CompilationPolicy::is_mature(MethodData* mdo) {
1132 if (Arguments::is_compiler_only()) {
1133 // Always report profiles as immature with -Xcomp
1134 return false;
1135 }
1136 methodHandle mh(Thread::current(), mdo->method());
1137 if (mdo != nullptr) {
1138 int i = mdo->invocation_count();
1139 int b = mdo->backedge_count();
1140 double k = ProfileMaturityPercentage / 100.0;
1141 return CallPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k) || LoopPredicate::apply_scaled(mh, CompLevel_full_profile, i, b, k);
1142 }
1143 return false;
1144 }
1145
1146 // If a method is old enough and is still in the interpreter we would want to
1147 // start profiling without waiting for the compiled method to arrive.
1148 // We also take the load on compilers into the account.
1149 bool CompilationPolicy::should_create_mdo(const methodHandle& method, CompLevel cur_level) {
1150 if (cur_level != CompLevel_none || force_comp_at_level_simple(method) || CompilationModeFlag::quick_only() || !ProfileInterpreter) {
1151 return false;
1152 }
1153
1154 if (TrainingData::have_data()) {
1155 MethodTrainingData* mtd = MethodTrainingData::find(method);
1156 if (mtd != nullptr && mtd->saw_level(CompLevel_full_optimization)) {
1157 return true;
1158 }
1159 return false;
1160 }
1161
1162 if (is_old(method)) {
1163 return true;
1164 }
1165
1166 int i = method->invocation_count();
1167 int b = method->backedge_count();
1168 double k = Tier0ProfilingStartPercentage / 100.0;
1169
1170 // If the top level compiler is not keeping up, delay profiling.
1171 if (CompileBroker::queue_size(CompLevel_full_optimization) <= Tier0Delay * compiler_count(CompLevel_full_optimization)) {
1172 return CallPredicate::apply_scaled(method, CompLevel_none, i, b, k) || LoopPredicate::apply_scaled(method, CompLevel_none, i, b, k);
1173 }
1174 return false;
1175 }
1176
1177 // Inlining control: if we're compiling a profiled method with C1 and the callee
1178 // is known to have OSRed in a C2 version, don't inline it.
1179 bool CompilationPolicy::should_not_inline(ciEnv* env, ciMethod* callee) {
1180 CompLevel comp_level = (CompLevel)env->comp_level();
1181 if (comp_level == CompLevel_full_profile ||
1182 comp_level == CompLevel_limited_profile) {
1183 return callee->highest_osr_comp_level() == CompLevel_full_optimization;
1184 }
1185 return false;
1186 }
1187
1188 // Create MDO if necessary.
1189 void CompilationPolicy::create_mdo(const methodHandle& mh, JavaThread* THREAD) {
1190 if (mh->is_native() ||
1191 mh->is_abstract() ||
1192 mh->is_accessor() ||
1193 mh->is_constant_getter()) {
1194 return;
1195 }
1196 if (mh->method_data() == nullptr) {
1197 Method::build_profiling_method_data(mh, CHECK_AND_CLEAR);
1198 }
1199 if (ProfileInterpreter && THREAD->has_last_Java_frame()) {
1200 MethodData* mdo = mh->method_data();
1201 if (mdo != nullptr) {
1202 frame last_frame = THREAD->last_frame();
1203 if (last_frame.is_interpreted_frame() && mh == last_frame.interpreter_frame_method()) {
1204 int bci = last_frame.interpreter_frame_bci();
1205 address dp = mdo->bci_to_dp(bci);
1206 last_frame.interpreter_frame_set_mdp(dp);
1207 }
1208 }
1209 }
1210 }
1211
1212 CompLevel CompilationPolicy::trained_transition_from_none(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1213 precond(mtd != nullptr);
1214 precond(cur_level == CompLevel_none);
1215
1216 if (mtd->only_inlined() && !mtd->saw_level(CompLevel_full_optimization)) {
1217 return CompLevel_none;
1218 }
1219
1220 bool training_has_profile = (mtd->final_profile() != nullptr);
1221 if (mtd->saw_level(CompLevel_full_optimization) && !training_has_profile) {
1222 return CompLevel_full_profile;
1223 }
1224
1225 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1226 switch (highest_training_level) {
1227 case CompLevel_limited_profile:
1228 case CompLevel_full_profile:
1229 return CompLevel_limited_profile;
1230 case CompLevel_simple:
1231 return CompLevel_simple;
1232 case CompLevel_none:
1233 return CompLevel_none;
1234 default:
1235 break;
1236 }
1237
1238 // Now handle the case of level 4.
1239 assert(highest_training_level == CompLevel_full_optimization, "Unexpected compilation level: %d", highest_training_level);
1240 if (!training_has_profile) {
1241 // The method was a part of a level 4 compile, but don't have a stored profile,
1242 // we need to profile it.
1243 return CompLevel_full_profile;
1244 }
1245 const bool deopt = (static_cast<CompLevel>(method->highest_comp_level()) == CompLevel_full_optimization);
1246 // If we deopted, then we reprofile
1247 if (deopt && !is_method_profiled(method)) {
1248 return CompLevel_full_profile;
1249 }
1250
1251 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1252 assert(ctd != nullptr, "Should have CTD for CompLevel_full_optimization");
1253 // With SkipTier2IfPossible and all deps satisfied, go to level 4 immediately
1254 if (SkipTier2IfPossible && ctd->init_deps_left() == 0) {
1255 if (method->method_data() == nullptr) {
1256 create_mdo(method, THREAD);
1257 }
1258 return CompLevel_full_optimization;
1259 }
1260
1261 // Otherwise go to level 2
1262 return CompLevel_limited_profile;
1263 }
1264
1265
1266 CompLevel CompilationPolicy::trained_transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1267 precond(mtd != nullptr);
1268 precond(cur_level == CompLevel_limited_profile);
1269
1270 // One of the main reasons that we can get here is that we're waiting for the stored C2 code to become ready.
1271
1272 // But first, check if we have a saved profile
1273 bool training_has_profile = (mtd->final_profile() != nullptr);
1274 if (!training_has_profile) {
1275 return CompLevel_full_profile;
1276 }
1277
1278
1279 assert(training_has_profile, "Have to have a profile to be here");
1280 // Check if the method is ready
1281 CompileTrainingData* ctd = mtd->last_toplevel_compile(CompLevel_full_optimization);
1282 if (ctd != nullptr && ctd->init_deps_left() == 0) {
1283 if (method->method_data() == nullptr) {
1284 create_mdo(method, THREAD);
1285 }
1286 return CompLevel_full_optimization;
1287 }
1288
1289 // Otherwise stay at the current level
1290 return CompLevel_limited_profile;
1291 }
1292
1293
1294 CompLevel CompilationPolicy::trained_transition_from_full_profile(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1295 precond(mtd != nullptr);
1296 precond(cur_level == CompLevel_full_profile);
1297
1298 CompLevel highest_training_level = static_cast<CompLevel>(mtd->highest_top_level());
1299 // We have method at the full profile level and we also know that it's possibly an important method.
1300 if (highest_training_level == CompLevel_full_optimization && !mtd->only_inlined()) {
1301 // Check if it is adequately profiled
1302 if (is_method_profiled(method)) {
1303 return CompLevel_full_optimization;
1304 }
1305 }
1306
1307 // Otherwise stay at the current level
1308 return CompLevel_full_profile;
1309 }
1310
1311 CompLevel CompilationPolicy::trained_transition(const methodHandle& method, CompLevel cur_level, MethodTrainingData* mtd, JavaThread* THREAD) {
1312 precond(MethodTrainingData::have_data());
1313
1314 // If there is no training data recorded for this method, bail out.
1315 if (mtd == nullptr) {
1316 return cur_level;
1317 }
1318
1319 CompLevel next_level = cur_level;
1320 switch(cur_level) {
1321 default: break;
1322 case CompLevel_none:
1323 next_level = trained_transition_from_none(method, cur_level, mtd, THREAD);
1324 break;
1325 case CompLevel_limited_profile:
1326 next_level = trained_transition_from_limited_profile(method, cur_level, mtd, THREAD);
1327 break;
1328 case CompLevel_full_profile:
1329 next_level = trained_transition_from_full_profile(method, cur_level, mtd, THREAD);
1330 break;
1331 }
1332
1333 // We don't have any special strategies for the C2-only compilation modes, so just fix up the levels for now.
1334 if (CompilationModeFlag::high_only_quick_internal() && CompLevel_simple < next_level && next_level < CompLevel_full_optimization) {
1335 return CompLevel_none;
1336 }
1337 if (CompilationModeFlag::high_only() && next_level < CompLevel_full_optimization) {
1338 return CompLevel_none;
1339 }
1340 return (cur_level != next_level) ? limit_level(next_level) : cur_level;
1341 }
1342
1343 /*
1344 * Method states:
1345 * 0 - interpreter (CompLevel_none)
1346 * 1 - pure C1 (CompLevel_simple)
1347 * 2 - C1 with invocation and backedge counting (CompLevel_limited_profile)
1348 * 3 - C1 with full profiling (CompLevel_full_profile)
1349 * 4 - C2 or Graal (CompLevel_full_optimization)
1350 *
1351 * Common state transition patterns:
1352 * a. 0 -> 3 -> 4.
1353 * The most common path. But note that even in this straightforward case
1354 * profiling can start at level 0 and finish at level 3.
1355 *
1356 * b. 0 -> 2 -> 3 -> 4.
1357 * This case occurs when the load on C2 is deemed too high. So, instead of transitioning
1358 * into state 3 directly and over-profiling while a method is in the C2 queue we transition to
1359 * level 2 and wait until the load on C2 decreases. This path is disabled for OSRs.
1360 *
1361 * c. 0 -> (3->2) -> 4.
1362 * In this case we enqueue a method for compilation at level 3, but the C1 queue is long enough
1363 * to enable the profiling to fully occur at level 0. In this case we change the compilation level
1364 * of the method to 2 while the request is still in-queue, because it'll allow it to run much faster
1365 * without full profiling while c2 is compiling.
1366 *
1367 * d. 0 -> 3 -> 1 or 0 -> 2 -> 1.
1368 * After a method was once compiled with C1 it can be identified as trivial and be compiled to
1369 * level 1. These transition can also occur if a method can't be compiled with C2 but can with C1.
1370 *
1371 * e. 0 -> 4.
1372 * This can happen if a method fails C1 compilation (it will still be profiled in the interpreter)
1373 * or because of a deopt that didn't require reprofiling (compilation won't happen in this case because
1374 * the compiled version already exists).
1375 *
1376 * Note that since state 0 can be reached from any other state via deoptimization different loops
1377 * are possible.
1378 *
1379 */
1380
1381 // Common transition function. Given a predicate determines if a method should transition to another level.
1382 template<typename Predicate>
1383 CompLevel CompilationPolicy::common(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD, bool disable_feedback) {
1384 CompLevel next_level = cur_level;
1385 int i = method->invocation_count();
1386 int b = method->backedge_count();
1387
1388 if (force_comp_at_level_simple(method)) {
1389 next_level = CompLevel_simple;
1390 } else {
1391 if (MethodTrainingData::have_data()) {
1392 MethodTrainingData* mtd = MethodTrainingData::find(method);
1393 if (mtd == nullptr) {
1394 // We haven't see compilations of this method in training. It's either very cold or the behavior changed.
1395 // Feed it to the standard TF with no profiling delay.
1396 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1397 } else {
1398 next_level = trained_transition(method, cur_level, mtd, THREAD);
1399 if (cur_level == next_level) {
1400 // trained_transtion() is going to return the same level if no startup/warmup optimizations apply.
1401 // In order to catch possible pathologies due to behavior change we feed the event to the regular
1402 // TF but with profiling delay.
1403 next_level = standard_transition<Predicate>(method, cur_level, true /*delay_profiling*/, disable_feedback);
1404 }
1405 }
1406 } else if (is_trivial(method) || method->is_native()) {
1407 next_level = CompilationModeFlag::disable_intermediate() ? CompLevel_full_optimization : CompLevel_simple;
1408 } else {
1409 next_level = standard_transition<Predicate>(method, cur_level, false /*delay_profiling*/, disable_feedback);
1410 }
1411 }
1412 return (next_level != cur_level) ? limit_level(next_level) : next_level;
1413 }
1414
1415
1416 template<typename Predicate>
1417 CompLevel CompilationPolicy::standard_transition(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1418 CompLevel next_level = cur_level;
1419 switch(cur_level) {
1420 default: break;
1421 case CompLevel_none:
1422 next_level = transition_from_none<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1423 break;
1424 case CompLevel_limited_profile:
1425 next_level = transition_from_limited_profile<Predicate>(method, cur_level, delay_profiling, disable_feedback);
1426 break;
1427 case CompLevel_full_profile:
1428 next_level = transition_from_full_profile<Predicate>(method, cur_level);
1429 break;
1430 }
1431 return next_level;
1432 }
1433
1434 template<typename Predicate>
1435 CompLevel CompilationPolicy::transition_from_none(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1436 precond(cur_level == CompLevel_none);
1437 CompLevel next_level = cur_level;
1438 int i = method->invocation_count();
1439 int b = method->backedge_count();
1440 double scale = delay_profiling ? Tier0ProfileDelayFactor : 1.0;
1441 // If we were at full profile level, would we switch to full opt?
1442 if (transition_from_full_profile<Predicate>(method, CompLevel_full_profile) == CompLevel_full_optimization) {
1443 next_level = CompLevel_full_optimization;
1444 } else if (!CompilationModeFlag::disable_intermediate() && Predicate::apply_scaled(method, cur_level, i, b, scale)) {
1445 // C1-generated fully profiled code is about 30% slower than the limited profile
1446 // code that has only invocation and backedge counters. The observation is that
1447 // if C2 queue is large enough we can spend too much time in the fully profiled code
1448 // while waiting for C2 to pick the method from the queue. To alleviate this problem
1449 // we introduce a feedback on the C2 queue size. If the C2 queue is sufficiently long
1450 // we choose to compile a limited profiled version and then recompile with full profiling
1451 // when the load on C2 goes down.
1452 if (delay_profiling || (!disable_feedback && CompileBroker::queue_size(CompLevel_full_optimization) > Tier3DelayOn * compiler_count(CompLevel_full_optimization))) {
1453 next_level = CompLevel_limited_profile;
1454 } else {
1455 next_level = CompLevel_full_profile;
1456 }
1457 }
1458 return next_level;
1459 }
1460
1461 template<typename Predicate>
1462 CompLevel CompilationPolicy::transition_from_full_profile(const methodHandle& method, CompLevel cur_level) {
1463 precond(cur_level == CompLevel_full_profile);
1464 CompLevel next_level = cur_level;
1465 MethodData* mdo = method->method_data();
1466 if (mdo != nullptr) {
1467 if (mdo->would_profile() || CompilationModeFlag::disable_intermediate()) {
1468 int mdo_i = mdo->invocation_count_delta();
1469 int mdo_b = mdo->backedge_count_delta();
1470 if (Predicate::apply(method, cur_level, mdo_i, mdo_b)) {
1471 next_level = CompLevel_full_optimization;
1472 }
1473 } else {
1474 next_level = CompLevel_full_optimization;
1475 }
1476 }
1477 return next_level;
1478 }
1479
1480 template<typename Predicate>
1481 CompLevel CompilationPolicy::transition_from_limited_profile(const methodHandle& method, CompLevel cur_level, bool delay_profiling, bool disable_feedback) {
1482 precond(cur_level == CompLevel_limited_profile);
1483 CompLevel next_level = cur_level;
1484 int i = method->invocation_count();
1485 int b = method->backedge_count();
1486 double scale = delay_profiling ? Tier2ProfileDelayFactor : 1.0;
1487 MethodData* mdo = method->method_data();
1488 if (mdo != nullptr) {
1489 if (mdo->would_profile()) {
1490 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1491 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1492 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1493 next_level = CompLevel_full_profile;
1494 }
1495 } else {
1496 next_level = CompLevel_full_optimization;
1497 }
1498 } else {
1499 // If there is no MDO we need to profile
1500 if (disable_feedback || (CompileBroker::queue_size(CompLevel_full_optimization) <=
1501 Tier3DelayOff * compiler_count(CompLevel_full_optimization) &&
1502 Predicate::apply_scaled(method, cur_level, i, b, scale))) {
1503 next_level = CompLevel_full_profile;
1504 }
1505 }
1506 if (next_level == CompLevel_full_profile && is_method_profiled(method)) {
1507 next_level = CompLevel_full_optimization;
1508 }
1509 return next_level;
1510 }
1511
1512
1513 // Determine if a method should be compiled with a normal entry point at a different level.
1514 CompLevel CompilationPolicy::call_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1515 CompLevel osr_level = MIN2((CompLevel) method->highest_osr_comp_level(), common<LoopPredicate>(method, cur_level, THREAD, true));
1516 CompLevel next_level = common<CallPredicate>(method, cur_level, THREAD, !TrainingData::have_data() && is_old(method));
1517
1518 // If OSR method level is greater than the regular method level, the levels should be
1519 // equalized by raising the regular method level in order to avoid OSRs during each
1520 // invocation of the method.
1521 if (osr_level == CompLevel_full_optimization && cur_level == CompLevel_full_profile) {
1522 MethodData* mdo = method->method_data();
1523 guarantee(mdo != nullptr, "MDO should not be nullptr");
1524 if (mdo->invocation_count() >= 1) {
1525 next_level = CompLevel_full_optimization;
1526 }
1527 } else {
1528 next_level = MAX2(osr_level, next_level);
1529 }
1530 #if INCLUDE_JVMCI
1531 if (EnableJVMCI && UseJVMCICompiler &&
1532 next_level == CompLevel_full_optimization && !AOTLinkedClassBulkLoader::class_preloading_finished()) {
1533 next_level = cur_level;
1534 }
1535 #endif
1536 return next_level;
1537 }
1538
1539 // Determine if we should do an OSR compilation of a given method.
1540 CompLevel CompilationPolicy::loop_event(const methodHandle& method, CompLevel cur_level, JavaThread* THREAD) {
1541 CompLevel next_level = common<LoopPredicate>(method, cur_level, THREAD, true);
1542 if (cur_level == CompLevel_none) {
1543 // If there is a live OSR method that means that we deopted to the interpreter
1544 // for the transition.
1545 CompLevel osr_level = MIN2((CompLevel)method->highest_osr_comp_level(), next_level);
1546 if (osr_level > CompLevel_none) {
1547 return osr_level;
1548 }
1549 }
1550 return next_level;
1551 }
1552
1553 // Handle the invocation event.
1554 void CompilationPolicy::method_invocation_event(const methodHandle& mh, const methodHandle& imh,
1555 CompLevel level, nmethod* nm, TRAPS) {
1556 if (should_create_mdo(mh, level)) {
1557 create_mdo(mh, THREAD);
1558 }
1559 CompLevel next_level = call_event(mh, level, THREAD);
1560 if (next_level != level) {
1561 if (is_compilation_enabled() && !CompileBroker::compilation_is_in_queue(mh)) {
1562 compile(mh, InvocationEntryBci, next_level, THREAD);
1563 }
1564 }
1565 }
1566
1567 // Handle the back branch event. Notice that we can compile the method
1568 // with a regular entry from here.
1569 void CompilationPolicy::method_back_branch_event(const methodHandle& mh, const methodHandle& imh,
1570 int bci, CompLevel level, nmethod* nm, TRAPS) {
1571 if (should_create_mdo(mh, level)) {
1572 create_mdo(mh, THREAD);
1573 }
1574 // Check if MDO should be created for the inlined method
1575 if (should_create_mdo(imh, level)) {
1576 create_mdo(imh, THREAD);
1577 }
1578
1579 if (is_compilation_enabled()) {
1580 CompLevel next_osr_level = loop_event(imh, level, THREAD);
1581 CompLevel max_osr_level = (CompLevel)imh->highest_osr_comp_level();
1582 // At the very least compile the OSR version
1583 if (!CompileBroker::compilation_is_in_queue(imh) && (next_osr_level != level)) {
1584 compile(imh, bci, next_osr_level, CHECK);
1585 }
1586
1587 // Use loop event as an opportunity to also check if there's been
1588 // enough calls.
1589 CompLevel cur_level, next_level;
1590 if (mh() != imh()) { // If there is an enclosing method
1591 {
1592 guarantee(nm != nullptr, "Should have nmethod here");
1593 cur_level = comp_level(mh());
1594 next_level = call_event(mh, cur_level, THREAD);
1595
1596 if (max_osr_level == CompLevel_full_optimization) {
1597 // The inlinee OSRed to full opt, we need to modify the enclosing method to avoid deopts
1598 bool make_not_entrant = false;
1599 if (nm->is_osr_method()) {
1600 // This is an osr method, just make it not entrant and recompile later if needed
1601 make_not_entrant = true;
1602 } else {
1603 if (next_level != CompLevel_full_optimization) {
1604 // next_level is not full opt, so we need to recompile the
1605 // enclosing method without the inlinee
1606 cur_level = CompLevel_none;
1607 make_not_entrant = true;
1608 }
1609 }
1610 if (make_not_entrant) {
1611 if (PrintTieredEvents) {
1612 int osr_bci = nm->is_osr_method() ? nm->osr_entry_bci() : InvocationEntryBci;
1613 print_event(MAKE_NOT_ENTRANT, mh(), mh(), osr_bci, level);
1614 }
1615 nm->make_not_entrant();
1616 }
1617 }
1618 // Fix up next_level if necessary to avoid deopts
1619 if (next_level == CompLevel_limited_profile && max_osr_level == CompLevel_full_profile) {
1620 next_level = CompLevel_full_profile;
1621 }
1622 if (cur_level != next_level) {
1623 if (!CompileBroker::compilation_is_in_queue(mh)) {
1624 compile(mh, InvocationEntryBci, next_level, THREAD);
1625 }
1626 }
1627 }
1628 } else {
1629 cur_level = comp_level(mh());
1630 next_level = call_event(mh, cur_level, THREAD);
1631 if (next_level != cur_level) {
1632 if (!CompileBroker::compilation_is_in_queue(mh)) {
1633 compile(mh, InvocationEntryBci, next_level, THREAD);
1634 }
1635 }
1636 }
1637 }
1638 }
1639