1 /* 2 * Copyright (c) 2000, 2016, 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 "code/compiledIC.hpp" 27 #include "code/nmethod.hpp" 28 #include "code/scopeDesc.hpp" 29 #include "interpreter/interpreter.hpp" 30 #include "memory/resourceArea.hpp" 31 #include "oops/methodData.hpp" 32 #include "oops/method.hpp" 33 #include "oops/oop.inline.hpp" 34 #include "prims/nativeLookup.hpp" 35 #include "runtime/advancedThresholdPolicy.hpp" 36 #include "runtime/compilationPolicy.hpp" 37 #include "runtime/frame.hpp" 38 #include "runtime/handles.inline.hpp" 39 #include "runtime/rframe.hpp" 40 #include "runtime/simpleThresholdPolicy.hpp" 41 #include "runtime/stubRoutines.hpp" 42 #include "runtime/thread.hpp" 43 #include "runtime/timer.hpp" 44 #include "runtime/vframe.hpp" 45 #include "runtime/vm_operations.hpp" 46 #include "utilities/events.hpp" 47 #include "utilities/globalDefinitions.hpp" 48 49 CompilationPolicy* CompilationPolicy::_policy; 50 elapsedTimer CompilationPolicy::_accumulated_time; 51 bool CompilationPolicy::_in_vm_startup; 52 53 // Determine compilation policy based on command line argument 54 void compilationPolicy_init() { 55 CompilationPolicy::set_in_vm_startup(DelayCompilationDuringStartup); 56 57 switch(CompilationPolicyChoice) { 58 case 0: 59 CompilationPolicy::set_policy(new SimpleCompPolicy()); 60 break; 61 62 case 1: 63 #ifdef COMPILER2 64 CompilationPolicy::set_policy(new StackWalkCompPolicy()); 65 #else 66 Unimplemented(); 67 #endif 68 break; 69 case 2: 70 #ifdef TIERED 71 CompilationPolicy::set_policy(new SimpleThresholdPolicy()); 72 #else 73 Unimplemented(); 74 #endif 75 break; 76 case 3: 77 #ifdef TIERED 78 CompilationPolicy::set_policy(new AdvancedThresholdPolicy()); 79 #else 80 Unimplemented(); 81 #endif 82 break; 83 default: 84 fatal("CompilationPolicyChoice must be in the range: [0-3]"); 85 } 86 CompilationPolicy::policy()->initialize(); 87 } 88 89 void CompilationPolicy::completed_vm_startup() { 90 if (TraceCompilationPolicy) { 91 tty->print("CompilationPolicy: completed vm startup.\n"); 92 } 93 _in_vm_startup = false; 94 } 95 96 // Returns true if m must be compiled before executing it 97 // This is intended to force compiles for methods (usually for 98 // debugging) that would otherwise be interpreted for some reason. 99 bool CompilationPolicy::must_be_compiled(methodHandle m, int comp_level) { 100 // Don't allow Xcomp to cause compiles in replay mode 101 if (ReplayCompiles) return false; 102 103 if (m->has_compiled_code()) return false; // already compiled 104 if (!can_be_compiled(m, comp_level)) return false; 105 106 return !UseInterpreter || // must compile all methods 107 (UseCompiler && AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods 108 } 109 110 void CompilationPolicy::compile_if_required(methodHandle selected_method, TRAPS) { 111 if (must_be_compiled(selected_method)) { 112 // This path is unusual, mostly used by the '-Xcomp' stress test mode. 113 114 // Note: with several active threads, the must_be_compiled may be true 115 // while can_be_compiled is false; remove assert 116 // assert(CompilationPolicy::can_be_compiled(selected_method), "cannot compile"); 117 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) { 118 // don't force compilation, resolve was on behalf of compiler 119 return; 120 } 121 if (selected_method->method_holder()->is_not_initialized()) { 122 // 'is_not_initialized' means not only '!is_initialized', but also that 123 // initialization has not been started yet ('!being_initialized') 124 // Do not force compilation of methods in uninitialized classes. 125 // Note that doing this would throw an assert later, 126 // in CompileBroker::compile_method. 127 // We sometimes use the link resolver to do reflective lookups 128 // even before classes are initialized. 129 return; 130 } 131 CompileBroker::compile_method(selected_method, InvocationEntryBci, 132 CompilationPolicy::policy()->initial_compile_level(), 133 methodHandle(), 0, CompileTask::Reason_MustBeCompiled, CHECK); 134 } 135 } 136 137 // Returns true if m is allowed to be compiled 138 bool CompilationPolicy::can_be_compiled(methodHandle m, int comp_level) { 139 // allow any levels for WhiteBox 140 assert(WhiteBoxAPI || comp_level == CompLevel_all || is_compile(comp_level), "illegal compilation level"); 141 142 if (m->is_abstract()) return false; 143 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false; 144 145 // Math intrinsics should never be compiled as this can lead to 146 // monotonicity problems because the interpreter will prefer the 147 // compiled code to the intrinsic version. This can't happen in 148 // production because the invocation counter can't be incremented 149 // but we shouldn't expose the system to this problem in testing 150 // modes. 151 if (!AbstractInterpreter::can_be_compiled(m)) { 152 return false; 153 } 154 if (comp_level == CompLevel_all) { 155 if (TieredCompilation) { 156 // enough to be compilable at any level for tiered 157 return !m->is_not_compilable(CompLevel_simple) || !m->is_not_compilable(CompLevel_full_optimization); 158 } else { 159 // must be compilable at available level for non-tiered 160 return !m->is_not_compilable(CompLevel_highest_tier); 161 } 162 } else if (is_compile(comp_level)) { 163 return !m->is_not_compilable(comp_level); 164 } 165 return false; 166 } 167 168 // Returns true if m is allowed to be osr compiled 169 bool CompilationPolicy::can_be_osr_compiled(methodHandle m, int comp_level) { 170 bool result = false; 171 if (comp_level == CompLevel_all) { 172 if (TieredCompilation) { 173 // enough to be osr compilable at any level for tiered 174 result = !m->is_not_osr_compilable(CompLevel_simple) || !m->is_not_osr_compilable(CompLevel_full_optimization); 175 } else { 176 // must be osr compilable at available level for non-tiered 177 result = !m->is_not_osr_compilable(CompLevel_highest_tier); 178 } 179 } else if (is_compile(comp_level)) { 180 result = !m->is_not_osr_compilable(comp_level); 181 } 182 return (result && can_be_compiled(m, comp_level)); 183 } 184 185 bool CompilationPolicy::is_compilation_enabled() { 186 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler 187 return !delay_compilation_during_startup() && CompileBroker::should_compile_new_jobs(); 188 } 189 190 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) { 191 #if INCLUDE_JVMCI 192 if (UseJVMCICompiler && !BackgroundCompilation) { 193 /* 194 * In blocking compilation mode, the CompileBroker will make 195 * compilations submitted by a JVMCI compiler thread non-blocking. These 196 * compilations should be scheduled after all blocking compilations 197 * to service non-compiler related compilations sooner and reduce the 198 * chance of such compilations timing out. 199 */ 200 for (CompileTask* task = compile_queue->first(); task != NULL; task = task->next()) { 201 if (task->is_blocking()) { 202 return task; 203 } 204 } 205 } 206 #endif 207 return compile_queue->first(); 208 } 209 210 #ifndef PRODUCT 211 void CompilationPolicy::print_time() { 212 tty->print_cr ("Accumulated compilationPolicy times:"); 213 tty->print_cr ("---------------------------"); 214 tty->print_cr (" Total: %3.3f sec.", _accumulated_time.seconds()); 215 } 216 217 void NonTieredCompPolicy::trace_osr_completion(nmethod* osr_nm) { 218 if (TraceOnStackReplacement) { 219 if (osr_nm == NULL) tty->print_cr("compilation failed"); 220 else tty->print_cr("nmethod " INTPTR_FORMAT, p2i(osr_nm)); 221 } 222 } 223 #endif // !PRODUCT 224 225 void NonTieredCompPolicy::initialize() { 226 // Setup the compiler thread numbers 227 if (CICompilerCountPerCPU) { 228 // Example: if CICompilerCountPerCPU is true, then we get 229 // max(log2(8)-1,1) = 2 compiler threads on an 8-way machine. 230 // May help big-app startup time. 231 _compiler_count = MAX2(log2_intptr(os::active_processor_count())-1,1); 232 FLAG_SET_ERGO(intx, CICompilerCount, _compiler_count); 233 } else { 234 _compiler_count = CICompilerCount; 235 } 236 } 237 238 // Note: this policy is used ONLY if TieredCompilation is off. 239 // compiler_count() behaves the following way: 240 // - with TIERED build (with both COMPILER1 and COMPILER2 defined) it should return 241 // zero for the c1 compilation levels in server compilation mode runs 242 // and c2 compilation levels in client compilation mode runs. 243 // - with COMPILER2 not defined it should return zero for c2 compilation levels. 244 // - with COMPILER1 not defined it should return zero for c1 compilation levels. 245 // - if neither is defined - always return zero. 246 int NonTieredCompPolicy::compiler_count(CompLevel comp_level) { 247 assert(!TieredCompilation, "This policy should not be used with TieredCompilation"); 248 if (COMPILER2_PRESENT(is_server_compilation_mode_vm() && is_c2_compile(comp_level) ||) 249 is_client_compilation_mode_vm() && is_c1_compile(comp_level)) { 250 return _compiler_count; 251 } 252 return 0; 253 } 254 255 void NonTieredCompPolicy::reset_counter_for_invocation_event(const methodHandle& m) { 256 // Make sure invocation and backedge counter doesn't overflow again right away 257 // as would be the case for native methods. 258 259 // BUT also make sure the method doesn't look like it was never executed. 260 // Set carry bit and reduce counter's value to min(count, CompileThreshold/2). 261 MethodCounters* mcs = m->method_counters(); 262 assert(mcs != NULL, "MethodCounters cannot be NULL for profiling"); 263 mcs->invocation_counter()->set_carry(); 264 mcs->backedge_counter()->set_carry(); 265 266 assert(!m->was_never_executed(), "don't reset to 0 -- could be mistaken for never-executed"); 267 } 268 269 void NonTieredCompPolicy::reset_counter_for_back_branch_event(const methodHandle& m) { 270 // Delay next back-branch event but pump up invocation counter to trigger 271 // whole method compilation. 272 MethodCounters* mcs = m->method_counters(); 273 assert(mcs != NULL, "MethodCounters cannot be NULL for profiling"); 274 InvocationCounter* i = mcs->invocation_counter(); 275 InvocationCounter* b = mcs->backedge_counter(); 276 277 // Don't set invocation_counter's value too low otherwise the method will 278 // look like immature (ic < ~5300) which prevents the inlining based on 279 // the type profiling. 280 i->set(i->state(), CompileThreshold); 281 // Don't reset counter too low - it is used to check if OSR method is ready. 282 b->set(b->state(), CompileThreshold / 2); 283 } 284 285 // 286 // CounterDecay 287 // 288 // Iterates through invocation counters and decrements them. This 289 // is done at each safepoint. 290 // 291 class CounterDecay : public AllStatic { 292 static jlong _last_timestamp; 293 static void do_method(Method* m) { 294 MethodCounters* mcs = m->method_counters(); 295 if (mcs != NULL) { 296 mcs->invocation_counter()->decay(); 297 } 298 } 299 public: 300 static void decay(); 301 static bool is_decay_needed() { 302 return (os::javaTimeMillis() - _last_timestamp) > CounterDecayMinIntervalLength; 303 } 304 }; 305 306 jlong CounterDecay::_last_timestamp = 0; 307 308 void CounterDecay::decay() { 309 _last_timestamp = os::javaTimeMillis(); 310 311 // This operation is going to be performed only at the end of a safepoint 312 // and hence GC's will not be going on, all Java mutators are suspended 313 // at this point and hence SystemDictionary_lock is also not needed. 314 assert(SafepointSynchronize::is_at_safepoint(), "can only be executed at a safepoint"); 315 int nclasses = InstanceKlass::number_of_instance_classes(); 316 double classes_per_tick = nclasses * (CounterDecayMinIntervalLength * 1e-3 / 317 CounterHalfLifeTime); 318 for (int i = 0; i < classes_per_tick; i++) { 319 InstanceKlass* k = ClassLoaderDataGraph::try_get_next_class(); 320 if (k != NULL) { 321 k->methods_do(do_method); 322 } 323 } 324 } 325 326 // Called at the end of the safepoint 327 void NonTieredCompPolicy::do_safepoint_work() { 328 if(UseCounterDecay && CounterDecay::is_decay_needed()) { 329 CounterDecay::decay(); 330 } 331 } 332 333 void NonTieredCompPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) { 334 ScopeDesc* sd = trap_scope; 335 MethodCounters* mcs; 336 InvocationCounter* c; 337 for (; !sd->is_top(); sd = sd->sender()) { 338 mcs = sd->method()->method_counters(); 339 if (mcs != NULL) { 340 // Reset ICs of inlined methods, since they can trigger compilations also. 341 mcs->invocation_counter()->reset(); 342 } 343 } 344 mcs = sd->method()->method_counters(); 345 if (mcs != NULL) { 346 c = mcs->invocation_counter(); 347 if (is_osr) { 348 // It was an OSR method, so bump the count higher. 349 c->set(c->state(), CompileThreshold); 350 } else { 351 c->reset(); 352 } 353 mcs->backedge_counter()->reset(); 354 } 355 } 356 357 // This method can be called by any component of the runtime to notify the policy 358 // that it's recommended to delay the compilation of this method. 359 void NonTieredCompPolicy::delay_compilation(Method* method) { 360 MethodCounters* mcs = method->method_counters(); 361 if (mcs != NULL) { 362 mcs->invocation_counter()->decay(); 363 mcs->backedge_counter()->decay(); 364 } 365 } 366 367 void NonTieredCompPolicy::disable_compilation(Method* method) { 368 MethodCounters* mcs = method->method_counters(); 369 if (mcs != NULL) { 370 mcs->invocation_counter()->set_state(InvocationCounter::wait_for_nothing); 371 mcs->backedge_counter()->set_state(InvocationCounter::wait_for_nothing); 372 } 373 } 374 375 CompileTask* NonTieredCompPolicy::select_task(CompileQueue* compile_queue) { 376 return select_task_helper(compile_queue); 377 } 378 379 bool NonTieredCompPolicy::is_mature(Method* method) { 380 MethodData* mdo = method->method_data(); 381 assert(mdo != NULL, "Should be"); 382 uint current = mdo->mileage_of(method); 383 uint initial = mdo->creation_mileage(); 384 if (current < initial) 385 return true; // some sort of overflow 386 uint target; 387 if (ProfileMaturityPercentage <= 0) 388 target = (uint) -ProfileMaturityPercentage; // absolute value 389 else 390 target = (uint)( (ProfileMaturityPercentage * CompileThreshold) / 100 ); 391 return (current >= initial + target); 392 } 393 394 nmethod* NonTieredCompPolicy::event(const methodHandle& method, const methodHandle& inlinee, int branch_bci, 395 int bci, CompLevel comp_level, CompiledMethod* nm, JavaThread* thread) { 396 assert(comp_level == CompLevel_none, "This should be only called from the interpreter"); 397 NOT_PRODUCT(trace_frequency_counter_overflow(method, branch_bci, bci)); 398 if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) { 399 // If certain JVMTI events (e.g. frame pop event) are requested then the 400 // thread is forced to remain in interpreted code. This is 401 // implemented partly by a check in the run_compiled_code 402 // section of the interpreter whether we should skip running 403 // compiled code, and partly by skipping OSR compiles for 404 // interpreted-only threads. 405 if (bci != InvocationEntryBci) { 406 reset_counter_for_back_branch_event(method); 407 return NULL; 408 } 409 } 410 if (CompileTheWorld || ReplayCompiles) { 411 // Don't trigger other compiles in testing mode 412 if (bci == InvocationEntryBci) { 413 reset_counter_for_invocation_event(method); 414 } else { 415 reset_counter_for_back_branch_event(method); 416 } 417 return NULL; 418 } 419 420 if (bci == InvocationEntryBci) { 421 // when code cache is full, compilation gets switched off, UseCompiler 422 // is set to false 423 if (!method->has_compiled_code() && UseCompiler) { 424 method_invocation_event(method, thread); 425 } else { 426 // Force counter overflow on method entry, even if no compilation 427 // happened. (The method_invocation_event call does this also.) 428 reset_counter_for_invocation_event(method); 429 } 430 // compilation at an invocation overflow no longer goes and retries test for 431 // compiled method. We always run the loser of the race as interpreted. 432 // so return NULL 433 return NULL; 434 } else { 435 // counter overflow in a loop => try to do on-stack-replacement 436 nmethod* osr_nm = method->lookup_osr_nmethod_for(bci, CompLevel_highest_tier, true); 437 NOT_PRODUCT(trace_osr_request(method, osr_nm, bci)); 438 // when code cache is full, we should not compile any more... 439 if (osr_nm == NULL && UseCompiler) { 440 method_back_branch_event(method, bci, thread); 441 osr_nm = method->lookup_osr_nmethod_for(bci, CompLevel_highest_tier, true); 442 } 443 if (osr_nm == NULL) { 444 reset_counter_for_back_branch_event(method); 445 return NULL; 446 } 447 return osr_nm; 448 } 449 return NULL; 450 } 451 452 #ifndef PRODUCT 453 void NonTieredCompPolicy::trace_frequency_counter_overflow(const methodHandle& m, int branch_bci, int bci) { 454 if (TraceInvocationCounterOverflow) { 455 MethodCounters* mcs = m->method_counters(); 456 assert(mcs != NULL, "MethodCounters cannot be NULL for profiling"); 457 InvocationCounter* ic = mcs->invocation_counter(); 458 InvocationCounter* bc = mcs->backedge_counter(); 459 ResourceMark rm; 460 if (bci == InvocationEntryBci) { 461 tty->print("comp-policy cntr ovfl @ %d in entry of ", bci); 462 } else { 463 tty->print("comp-policy cntr ovfl @ %d in loop of ", bci); 464 } 465 m->print_value(); 466 tty->cr(); 467 ic->print(); 468 bc->print(); 469 if (ProfileInterpreter) { 470 if (bci != InvocationEntryBci) { 471 MethodData* mdo = m->method_data(); 472 if (mdo != NULL) { 473 int count = mdo->bci_to_data(branch_bci)->as_JumpData()->taken(); 474 tty->print_cr("back branch count = %d", count); 475 } 476 } 477 } 478 } 479 } 480 481 void NonTieredCompPolicy::trace_osr_request(const methodHandle& method, nmethod* osr, int bci) { 482 if (TraceOnStackReplacement) { 483 ResourceMark rm; 484 tty->print(osr != NULL ? "Reused OSR entry for " : "Requesting OSR entry for "); 485 method->print_short_name(tty); 486 tty->print_cr(" at bci %d", bci); 487 } 488 } 489 #endif // !PRODUCT 490 491 // SimpleCompPolicy - compile current method 492 493 void SimpleCompPolicy::method_invocation_event(const methodHandle& m, JavaThread* thread) { 494 const int comp_level = CompLevel_highest_tier; 495 const int hot_count = m->invocation_count(); 496 reset_counter_for_invocation_event(m); 497 498 if (is_compilation_enabled() && can_be_compiled(m, comp_level)) { 499 CompiledMethod* nm = m->code(); 500 if (nm == NULL ) { 501 CompileBroker::compile_method(m, InvocationEntryBci, comp_level, m, hot_count, CompileTask::Reason_InvocationCount, thread); 502 } 503 } 504 } 505 506 void SimpleCompPolicy::method_back_branch_event(const methodHandle& m, int bci, JavaThread* thread) { 507 const int comp_level = CompLevel_highest_tier; 508 const int hot_count = m->backedge_count(); 509 510 if (is_compilation_enabled() && can_be_osr_compiled(m, comp_level)) { 511 CompileBroker::compile_method(m, bci, comp_level, m, hot_count, CompileTask::Reason_BackedgeCount, thread); 512 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(bci, comp_level, true));) 513 } 514 } 515 // StackWalkCompPolicy - walk up stack to find a suitable method to compile 516 517 #ifdef COMPILER2 518 const char* StackWalkCompPolicy::_msg = NULL; 519 520 521 // Consider m for compilation 522 void StackWalkCompPolicy::method_invocation_event(const methodHandle& m, JavaThread* thread) { 523 const int comp_level = CompLevel_highest_tier; 524 const int hot_count = m->invocation_count(); 525 reset_counter_for_invocation_event(m); 526 527 if (is_compilation_enabled() && m->code() == NULL && can_be_compiled(m, comp_level)) { 528 ResourceMark rm(thread); 529 frame fr = thread->last_frame(); 530 assert(fr.is_interpreted_frame(), "must be interpreted"); 531 assert(fr.interpreter_frame_method() == m(), "bad method"); 532 533 if (TraceCompilationPolicy) { 534 tty->print("method invocation trigger: "); 535 m->print_short_name(tty); 536 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", p2i((address)m()), m->code_size()); 537 } 538 RegisterMap reg_map(thread, false); 539 javaVFrame* triggerVF = thread->last_java_vframe(®_map); 540 // triggerVF is the frame that triggered its counter 541 RFrame* first = new InterpretedRFrame(triggerVF->fr(), thread, m()); 542 543 if (first->top_method()->code() != NULL) { 544 // called obsolete method/nmethod -- no need to recompile 545 if (TraceCompilationPolicy) tty->print_cr(" --> " INTPTR_FORMAT, p2i(first->top_method()->code())); 546 } else { 547 if (TimeCompilationPolicy) accumulated_time()->start(); 548 GrowableArray<RFrame*>* stack = new GrowableArray<RFrame*>(50); 549 stack->push(first); 550 RFrame* top = findTopInlinableFrame(stack); 551 if (TimeCompilationPolicy) accumulated_time()->stop(); 552 assert(top != NULL, "findTopInlinableFrame returned null"); 553 if (TraceCompilationPolicy) top->print(); 554 CompileBroker::compile_method(top->top_method(), InvocationEntryBci, comp_level, 555 m, hot_count, CompileTask::Reason_InvocationCount, thread); 556 } 557 } 558 } 559 560 void StackWalkCompPolicy::method_back_branch_event(const methodHandle& m, int bci, JavaThread* thread) { 561 const int comp_level = CompLevel_highest_tier; 562 const int hot_count = m->backedge_count(); 563 564 if (is_compilation_enabled() && can_be_osr_compiled(m, comp_level)) { 565 CompileBroker::compile_method(m, bci, comp_level, m, hot_count, CompileTask::Reason_BackedgeCount, thread); 566 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(bci, comp_level, true));) 567 } 568 } 569 570 RFrame* StackWalkCompPolicy::findTopInlinableFrame(GrowableArray<RFrame*>* stack) { 571 // go up the stack until finding a frame that (probably) won't be inlined 572 // into its caller 573 RFrame* current = stack->at(0); // current choice for stopping 574 assert( current && !current->is_compiled(), "" ); 575 const char* msg = NULL; 576 577 while (1) { 578 579 // before going up the stack further, check if doing so would get us into 580 // compiled code 581 RFrame* next = senderOf(current, stack); 582 if( !next ) // No next frame up the stack? 583 break; // Then compile with current frame 584 585 Method* m = current->top_method(); 586 Method* next_m = next->top_method(); 587 588 if (TraceCompilationPolicy && Verbose) { 589 tty->print("[caller: "); 590 next_m->print_short_name(tty); 591 tty->print("] "); 592 } 593 594 if( !Inline ) { // Inlining turned off 595 msg = "Inlining turned off"; 596 break; 597 } 598 if (next_m->is_not_compilable()) { // Did fail to compile this before/ 599 msg = "caller not compilable"; 600 break; 601 } 602 if (next->num() > MaxRecompilationSearchLength) { 603 // don't go up too high when searching for recompilees 604 msg = "don't go up any further: > MaxRecompilationSearchLength"; 605 break; 606 } 607 if (next->distance() > MaxInterpretedSearchLength) { 608 // don't go up too high when searching for recompilees 609 msg = "don't go up any further: next > MaxInterpretedSearchLength"; 610 break; 611 } 612 // Compiled frame above already decided not to inline; 613 // do not recompile him. 614 if (next->is_compiled()) { 615 msg = "not going up into optimized code"; 616 break; 617 } 618 619 // Interpreted frame above us was already compiled. Do not force 620 // a recompile, although if the frame above us runs long enough an 621 // OSR might still happen. 622 if( current->is_interpreted() && next_m->has_compiled_code() ) { 623 msg = "not going up -- already compiled caller"; 624 break; 625 } 626 627 // Compute how frequent this call site is. We have current method 'm'. 628 // We know next method 'next_m' is interpreted. Find the call site and 629 // check the various invocation counts. 630 int invcnt = 0; // Caller counts 631 if (ProfileInterpreter) { 632 invcnt = next_m->interpreter_invocation_count(); 633 } 634 int cnt = 0; // Call site counts 635 if (ProfileInterpreter && next_m->method_data() != NULL) { 636 ResourceMark rm; 637 int bci = next->top_vframe()->bci(); 638 ProfileData* data = next_m->method_data()->bci_to_data(bci); 639 if (data != NULL && data->is_CounterData()) 640 cnt = data->as_CounterData()->count(); 641 } 642 643 // Caller counts / call-site counts; i.e. is this call site 644 // a hot call site for method next_m? 645 int freq = (invcnt) ? cnt/invcnt : cnt; 646 647 // Check size and frequency limits 648 if ((msg = shouldInline(m, freq, cnt)) != NULL) { 649 break; 650 } 651 // Check inlining negative tests 652 if ((msg = shouldNotInline(m)) != NULL) { 653 break; 654 } 655 656 657 // If the caller method is too big or something then we do not want to 658 // compile it just to inline a method 659 if (!can_be_compiled(next_m, CompLevel_any)) { 660 msg = "caller cannot be compiled"; 661 break; 662 } 663 664 if( next_m->name() == vmSymbols::class_initializer_name() ) { 665 msg = "do not compile class initializer (OSR ok)"; 666 break; 667 } 668 669 if (TraceCompilationPolicy && Verbose) { 670 tty->print("\n\t check caller: "); 671 next_m->print_short_name(tty); 672 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", p2i((address)next_m), next_m->code_size()); 673 } 674 675 current = next; 676 } 677 678 assert( !current || !current->is_compiled(), "" ); 679 680 if (TraceCompilationPolicy && msg) tty->print("(%s)\n", msg); 681 682 return current; 683 } 684 685 RFrame* StackWalkCompPolicy::senderOf(RFrame* rf, GrowableArray<RFrame*>* stack) { 686 RFrame* sender = rf->caller(); 687 if (sender && sender->num() == stack->length()) stack->push(sender); 688 return sender; 689 } 690 691 692 const char* StackWalkCompPolicy::shouldInline(const methodHandle& m, float freq, int cnt) { 693 // Allows targeted inlining 694 // positive filter: should send be inlined? returns NULL (--> yes) 695 // or rejection msg 696 int max_size = MaxInlineSize; 697 int cost = m->code_size(); 698 699 // Check for too many throws (and not too huge) 700 if (m->interpreter_throwout_count() > InlineThrowCount && cost < InlineThrowMaxSize ) { 701 return NULL; 702 } 703 704 // bump the max size if the call is frequent 705 if ((freq >= InlineFrequencyRatio) || (cnt >= InlineFrequencyCount)) { 706 if (TraceFrequencyInlining) { 707 tty->print("(Inlined frequent method)\n"); 708 m->print(); 709 } 710 max_size = FreqInlineSize; 711 } 712 if (cost > max_size) { 713 return (_msg = "too big"); 714 } 715 return NULL; 716 } 717 718 719 const char* StackWalkCompPolicy::shouldNotInline(const methodHandle& m) { 720 // negative filter: should send NOT be inlined? returns NULL (--> inline) or rejection msg 721 if (m->is_abstract()) return (_msg = "abstract method"); 722 // note: we allow ik->is_abstract() 723 if (!m->method_holder()->is_initialized()) return (_msg = "method holder not initialized"); 724 if (m->is_native()) return (_msg = "native method"); 725 CompiledMethod* m_code = m->code(); 726 if (m_code != NULL && m_code->code_size() > InlineSmallCode) 727 return (_msg = "already compiled into a big method"); 728 729 // use frequency-based objections only for non-trivial methods 730 if (m->code_size() <= MaxTrivialSize) return NULL; 731 if (UseInterpreter) { // don't use counts with -Xcomp 732 if ((m->code() == NULL) && m->was_never_executed()) return (_msg = "never executed"); 733 if (!m->was_executed_more_than(MIN2(MinInliningThreshold, CompileThreshold >> 1))) return (_msg = "executed < MinInliningThreshold times"); 734 } 735 if (Method::has_unloaded_classes_in_signature(m, JavaThread::current())) return (_msg = "unloaded signature classes"); 736 737 return NULL; 738 } 739 740 741 742 #endif // COMPILER2