1 /* 2 * Copyright (c) 2000, 2018, 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 "classfile/classLoaderDataGraph.inline.hpp" 27 #include "code/compiledIC.hpp" 28 #include "code/nmethod.hpp" 29 #include "code/scopeDesc.hpp" 30 #include "interpreter/interpreter.hpp" 31 #include "memory/resourceArea.hpp" 32 #include "oops/methodData.hpp" 33 #include "oops/method.inline.hpp" 34 #include "oops/oop.inline.hpp" 35 #include "prims/nativeLookup.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/stubRoutines.hpp" 41 #include "runtime/thread.hpp" 42 #include "runtime/tieredThresholdPolicy.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 TieredThresholdPolicy()); 72 #else 73 Unimplemented(); 74 #endif 75 break; 76 default: 77 fatal("CompilationPolicyChoice must be in the range: [0-2]"); 78 } 79 CompilationPolicy::policy()->initialize(); 80 } 81 82 void CompilationPolicy::completed_vm_startup() { 83 if (TraceCompilationPolicy) { 84 tty->print("CompilationPolicy: completed vm startup.\n"); 85 } 86 _in_vm_startup = false; 87 } 88 89 // Returns true if m must be compiled before executing it 90 // This is intended to force compiles for methods (usually for 91 // debugging) that would otherwise be interpreted for some reason. 92 bool CompilationPolicy::must_be_compiled(const methodHandle& m, int comp_level) { 93 // Don't allow Xcomp to cause compiles in replay mode 94 if (ReplayCompiles) return false; 95 96 if (m->has_compiled_code()) return false; // already compiled 97 if (!can_be_compiled(m, comp_level)) return false; 98 99 return !UseInterpreter || // must compile all methods 100 (UseCompiler && AlwaysCompileLoopMethods && m->has_loops() && CompileBroker::should_compile_new_jobs()); // eagerly compile loop methods 101 } 102 103 void CompilationPolicy::compile_if_required(const methodHandle& selected_method, TRAPS) { 104 if (must_be_compiled(selected_method)) { 105 // This path is unusual, mostly used by the '-Xcomp' stress test mode. 106 107 // Note: with several active threads, the must_be_compiled may be true 108 // while can_be_compiled is false; remove assert 109 // assert(CompilationPolicy::can_be_compiled(selected_method), "cannot compile"); 110 if (!THREAD->can_call_java() || THREAD->is_Compiler_thread()) { 111 // don't force compilation, resolve was on behalf of compiler 112 return; 113 } 114 if (selected_method->method_holder()->is_not_initialized()) { 115 // 'is_not_initialized' means not only '!is_initialized', but also that 116 // initialization has not been started yet ('!being_initialized') 117 // Do not force compilation of methods in uninitialized classes. 118 // Note that doing this would throw an assert later, 119 // in CompileBroker::compile_method. 120 // We sometimes use the link resolver to do reflective lookups 121 // even before classes are initialized. 122 return; 123 } 124 CompileBroker::compile_method(selected_method, InvocationEntryBci, 125 CompilationPolicy::policy()->initial_compile_level(), 126 methodHandle(), 0, CompileTask::Reason_MustBeCompiled, CHECK); 127 } 128 } 129 130 // Returns true if m is allowed to be compiled 131 bool CompilationPolicy::can_be_compiled(const methodHandle& m, int comp_level) { 132 // allow any levels for WhiteBox 133 assert(WhiteBoxAPI || comp_level == CompLevel_all || is_compile(comp_level), "illegal compilation level"); 134 135 if (m->is_abstract()) return false; 136 if (DontCompileHugeMethods && m->code_size() > HugeMethodLimit) return false; 137 138 // Math intrinsics should never be compiled as this can lead to 139 // monotonicity problems because the interpreter will prefer the 140 // compiled code to the intrinsic version. This can't happen in 141 // production because the invocation counter can't be incremented 142 // but we shouldn't expose the system to this problem in testing 143 // modes. 144 if (!AbstractInterpreter::can_be_compiled(m)) { 145 return false; 146 } 147 if (comp_level == CompLevel_all) { 148 if (TieredCompilation) { 149 // enough to be compilable at any level for tiered 150 return !m->is_not_compilable(CompLevel_simple) || !m->is_not_compilable(CompLevel_full_optimization); 151 } else { 152 // must be compilable at available level for non-tiered 153 return !m->is_not_compilable(CompLevel_highest_tier); 154 } 155 } else if (is_compile(comp_level)) { 156 return !m->is_not_compilable(comp_level); 157 } 158 return false; 159 } 160 161 // Returns true if m is allowed to be osr compiled 162 bool CompilationPolicy::can_be_osr_compiled(const methodHandle& m, int comp_level) { 163 bool result = false; 164 if (comp_level == CompLevel_all) { 165 if (TieredCompilation) { 166 // enough to be osr compilable at any level for tiered 167 result = !m->is_not_osr_compilable(CompLevel_simple) || !m->is_not_osr_compilable(CompLevel_full_optimization); 168 } else { 169 // must be osr compilable at available level for non-tiered 170 result = !m->is_not_osr_compilable(CompLevel_highest_tier); 171 } 172 } else if (is_compile(comp_level)) { 173 result = !m->is_not_osr_compilable(comp_level); 174 } 175 return (result && can_be_compiled(m, comp_level)); 176 } 177 178 bool CompilationPolicy::is_compilation_enabled() { 179 // NOTE: CompileBroker::should_compile_new_jobs() checks for UseCompiler 180 return !delay_compilation_during_startup() && CompileBroker::should_compile_new_jobs(); 181 } 182 183 CompileTask* CompilationPolicy::select_task_helper(CompileQueue* compile_queue) { 184 #if INCLUDE_JVMCI 185 if (UseJVMCICompiler && !BackgroundCompilation) { 186 /* 187 * In blocking compilation mode, the CompileBroker will make 188 * compilations submitted by a JVMCI compiler thread non-blocking. These 189 * compilations should be scheduled after all blocking compilations 190 * to service non-compiler related compilations sooner and reduce the 191 * chance of such compilations timing out. 192 */ 193 for (CompileTask* task = compile_queue->first(); task != NULL; task = task->next()) { 194 if (task->is_blocking()) { 195 return task; 196 } 197 } 198 } 199 #endif 200 return compile_queue->first(); 201 } 202 203 #ifndef PRODUCT 204 void CompilationPolicy::print_time() { 205 tty->print_cr ("Accumulated compilationPolicy times:"); 206 tty->print_cr ("---------------------------"); 207 tty->print_cr (" Total: %3.3f sec.", _accumulated_time.seconds()); 208 } 209 210 void NonTieredCompPolicy::trace_osr_completion(nmethod* osr_nm) { 211 if (TraceOnStackReplacement) { 212 if (osr_nm == NULL) tty->print_cr("compilation failed"); 213 else tty->print_cr("nmethod " INTPTR_FORMAT, p2i(osr_nm)); 214 } 215 } 216 #endif // !PRODUCT 217 218 void NonTieredCompPolicy::initialize() { 219 // Setup the compiler thread numbers 220 if (CICompilerCountPerCPU) { 221 // Example: if CICompilerCountPerCPU is true, then we get 222 // max(log2(8)-1,1) = 2 compiler threads on an 8-way machine. 223 // May help big-app startup time. 224 _compiler_count = MAX2(log2_intptr(os::active_processor_count())-1,1); 225 FLAG_SET_ERGO(intx, CICompilerCount, _compiler_count); 226 } else { 227 _compiler_count = CICompilerCount; 228 } 229 } 230 231 // Note: this policy is used ONLY if TieredCompilation is off. 232 // compiler_count() behaves the following way: 233 // - with TIERED build (with both COMPILER1 and COMPILER2 defined) it should return 234 // zero for the c1 compilation levels in server compilation mode runs 235 // and c2 compilation levels in client compilation mode runs. 236 // - with COMPILER2 not defined it should return zero for c2 compilation levels. 237 // - with COMPILER1 not defined it should return zero for c1 compilation levels. 238 // - if neither is defined - always return zero. 239 int NonTieredCompPolicy::compiler_count(CompLevel comp_level) { 240 assert(!TieredCompilation, "This policy should not be used with TieredCompilation"); 241 if (COMPILER2_PRESENT(is_server_compilation_mode_vm() && is_c2_compile(comp_level) ||) 242 is_client_compilation_mode_vm() && is_c1_compile(comp_level)) { 243 return _compiler_count; 244 } 245 return 0; 246 } 247 248 void NonTieredCompPolicy::reset_counter_for_invocation_event(const methodHandle& m) { 249 // Make sure invocation and backedge counter doesn't overflow again right away 250 // as would be the case for native methods. 251 252 // BUT also make sure the method doesn't look like it was never executed. 253 // Set carry bit and reduce counter's value to min(count, CompileThreshold/2). 254 MethodCounters* mcs = m->method_counters(); 255 assert(mcs != NULL, "MethodCounters cannot be NULL for profiling"); 256 mcs->invocation_counter()->set_carry(); 257 mcs->backedge_counter()->set_carry(); 258 259 assert(!m->was_never_executed(), "don't reset to 0 -- could be mistaken for never-executed"); 260 } 261 262 void NonTieredCompPolicy::reset_counter_for_back_branch_event(const methodHandle& m) { 263 // Delay next back-branch event but pump up invocation counter to trigger 264 // whole method compilation. 265 MethodCounters* mcs = m->method_counters(); 266 assert(mcs != NULL, "MethodCounters cannot be NULL for profiling"); 267 InvocationCounter* i = mcs->invocation_counter(); 268 InvocationCounter* b = mcs->backedge_counter(); 269 270 // Don't set invocation_counter's value too low otherwise the method will 271 // look like immature (ic < ~5300) which prevents the inlining based on 272 // the type profiling. 273 i->set(i->state(), CompileThreshold); 274 // Don't reset counter too low - it is used to check if OSR method is ready. 275 b->set(b->state(), CompileThreshold / 2); 276 } 277 278 // 279 // CounterDecay 280 // 281 // Iterates through invocation counters and decrements them. This 282 // is done at each safepoint. 283 // 284 class CounterDecay : public AllStatic { 285 static jlong _last_timestamp; 286 static void do_method(Method* m) { 287 MethodCounters* mcs = m->method_counters(); 288 if (mcs != NULL) { 289 mcs->invocation_counter()->decay(); 290 } 291 } 292 public: 293 static void decay(); 294 static bool is_decay_needed() { 295 return (os::javaTimeMillis() - _last_timestamp) > CounterDecayMinIntervalLength; 296 } 297 }; 298 299 jlong CounterDecay::_last_timestamp = 0; 300 301 void CounterDecay::decay() { 302 _last_timestamp = os::javaTimeMillis(); 303 304 // This operation is going to be performed only at the end of a safepoint 305 // and hence GC's will not be going on, all Java mutators are suspended 306 // at this point and hence SystemDictionary_lock is also not needed. 307 assert(SafepointSynchronize::is_at_safepoint(), "can only be executed at a safepoint"); 308 size_t nclasses = ClassLoaderDataGraph::num_instance_classes(); 309 size_t classes_per_tick = nclasses * (CounterDecayMinIntervalLength * 1e-3 / 310 CounterHalfLifeTime); 311 for (size_t i = 0; i < classes_per_tick; i++) { 312 InstanceKlass* k = ClassLoaderDataGraph::try_get_next_class(); 313 if (k != NULL) { 314 k->methods_do(do_method); 315 } 316 } 317 } 318 319 // Called at the end of the safepoint 320 void NonTieredCompPolicy::do_safepoint_work() { 321 if(UseCounterDecay && CounterDecay::is_decay_needed()) { 322 CounterDecay::decay(); 323 } 324 } 325 326 void NonTieredCompPolicy::reprofile(ScopeDesc* trap_scope, bool is_osr) { 327 ScopeDesc* sd = trap_scope; 328 MethodCounters* mcs; 329 InvocationCounter* c; 330 for (; !sd->is_top(); sd = sd->sender()) { 331 mcs = sd->method()->method_counters(); 332 if (mcs != NULL) { 333 // Reset ICs of inlined methods, since they can trigger compilations also. 334 mcs->invocation_counter()->reset(); 335 } 336 } 337 mcs = sd->method()->method_counters(); 338 if (mcs != NULL) { 339 c = mcs->invocation_counter(); 340 if (is_osr) { 341 // It was an OSR method, so bump the count higher. 342 c->set(c->state(), CompileThreshold); 343 } else { 344 c->reset(); 345 } 346 mcs->backedge_counter()->reset(); 347 } 348 } 349 350 // This method can be called by any component of the runtime to notify the policy 351 // that it's recommended to delay the compilation of this method. 352 void NonTieredCompPolicy::delay_compilation(Method* method) { 353 MethodCounters* mcs = method->method_counters(); 354 if (mcs != NULL) { 355 mcs->invocation_counter()->decay(); 356 mcs->backedge_counter()->decay(); 357 } 358 } 359 360 void NonTieredCompPolicy::disable_compilation(Method* method) { 361 MethodCounters* mcs = method->method_counters(); 362 if (mcs != NULL) { 363 mcs->invocation_counter()->set_state(InvocationCounter::wait_for_nothing); 364 mcs->backedge_counter()->set_state(InvocationCounter::wait_for_nothing); 365 } 366 } 367 368 CompileTask* NonTieredCompPolicy::select_task(CompileQueue* compile_queue) { 369 return select_task_helper(compile_queue); 370 } 371 372 bool NonTieredCompPolicy::is_mature(Method* method) { 373 MethodData* mdo = method->method_data(); 374 assert(mdo != NULL, "Should be"); 375 uint current = mdo->mileage_of(method); 376 uint initial = mdo->creation_mileage(); 377 if (current < initial) 378 return true; // some sort of overflow 379 uint target; 380 if (ProfileMaturityPercentage <= 0) 381 target = (uint) -ProfileMaturityPercentage; // absolute value 382 else 383 target = (uint)( (ProfileMaturityPercentage * CompileThreshold) / 100 ); 384 return (current >= initial + target); 385 } 386 387 nmethod* NonTieredCompPolicy::event(const methodHandle& method, const methodHandle& inlinee, int branch_bci, 388 int bci, CompLevel comp_level, CompiledMethod* nm, JavaThread* thread) { 389 assert(comp_level == CompLevel_none, "This should be only called from the interpreter"); 390 NOT_PRODUCT(trace_frequency_counter_overflow(method, branch_bci, bci)); 391 if (JvmtiExport::can_post_interpreter_events() && thread->is_interp_only_mode()) { 392 // If certain JVMTI events (e.g. frame pop event) are requested then the 393 // thread is forced to remain in interpreted code. This is 394 // implemented partly by a check in the run_compiled_code 395 // section of the interpreter whether we should skip running 396 // compiled code, and partly by skipping OSR compiles for 397 // interpreted-only threads. 398 if (bci != InvocationEntryBci) { 399 reset_counter_for_back_branch_event(method); 400 return NULL; 401 } 402 } 403 if (CompileTheWorld || ReplayCompiles) { 404 // Don't trigger other compiles in testing mode 405 if (bci == InvocationEntryBci) { 406 reset_counter_for_invocation_event(method); 407 } else { 408 reset_counter_for_back_branch_event(method); 409 } 410 return NULL; 411 } 412 413 if (bci == InvocationEntryBci) { 414 // when code cache is full, compilation gets switched off, UseCompiler 415 // is set to false 416 if (!method->has_compiled_code() && UseCompiler) { 417 method_invocation_event(method, thread); 418 } else { 419 // Force counter overflow on method entry, even if no compilation 420 // happened. (The method_invocation_event call does this also.) 421 reset_counter_for_invocation_event(method); 422 } 423 // compilation at an invocation overflow no longer goes and retries test for 424 // compiled method. We always run the loser of the race as interpreted. 425 // so return NULL 426 return NULL; 427 } else { 428 // counter overflow in a loop => try to do on-stack-replacement 429 nmethod* osr_nm = method->lookup_osr_nmethod_for(bci, CompLevel_highest_tier, true); 430 NOT_PRODUCT(trace_osr_request(method, osr_nm, bci)); 431 // when code cache is full, we should not compile any more... 432 if (osr_nm == NULL && UseCompiler) { 433 method_back_branch_event(method, bci, thread); 434 osr_nm = method->lookup_osr_nmethod_for(bci, CompLevel_highest_tier, true); 435 } 436 if (osr_nm == NULL) { 437 reset_counter_for_back_branch_event(method); 438 return NULL; 439 } 440 return osr_nm; 441 } 442 return NULL; 443 } 444 445 #ifndef PRODUCT 446 void NonTieredCompPolicy::trace_frequency_counter_overflow(const methodHandle& m, int branch_bci, int bci) { 447 if (TraceInvocationCounterOverflow) { 448 MethodCounters* mcs = m->method_counters(); 449 assert(mcs != NULL, "MethodCounters cannot be NULL for profiling"); 450 InvocationCounter* ic = mcs->invocation_counter(); 451 InvocationCounter* bc = mcs->backedge_counter(); 452 ResourceMark rm; 453 if (bci == InvocationEntryBci) { 454 tty->print("comp-policy cntr ovfl @ %d in entry of ", bci); 455 } else { 456 tty->print("comp-policy cntr ovfl @ %d in loop of ", bci); 457 } 458 m->print_value(); 459 tty->cr(); 460 ic->print(); 461 bc->print(); 462 if (ProfileInterpreter) { 463 if (bci != InvocationEntryBci) { 464 MethodData* mdo = m->method_data(); 465 if (mdo != NULL) { 466 ProfileData *pd = mdo->bci_to_data(branch_bci); 467 if (pd == NULL) { 468 tty->print_cr("back branch count = N/A (missing ProfileData)"); 469 } else { 470 tty->print_cr("back branch count = %d", pd->as_JumpData()->taken()); 471 } 472 } 473 } 474 } 475 } 476 } 477 478 void NonTieredCompPolicy::trace_osr_request(const methodHandle& method, nmethod* osr, int bci) { 479 if (TraceOnStackReplacement) { 480 ResourceMark rm; 481 tty->print(osr != NULL ? "Reused OSR entry for " : "Requesting OSR entry for "); 482 method->print_short_name(tty); 483 tty->print_cr(" at bci %d", bci); 484 } 485 } 486 #endif // !PRODUCT 487 488 // SimpleCompPolicy - compile current method 489 490 void SimpleCompPolicy::method_invocation_event(const methodHandle& m, JavaThread* thread) { 491 const int comp_level = CompLevel_highest_tier; 492 const int hot_count = m->invocation_count(); 493 reset_counter_for_invocation_event(m); 494 495 if (is_compilation_enabled() && can_be_compiled(m, comp_level)) { 496 CompiledMethod* nm = m->code(); 497 if (nm == NULL ) { 498 CompileBroker::compile_method(m, InvocationEntryBci, comp_level, m, hot_count, CompileTask::Reason_InvocationCount, thread); 499 } 500 } 501 } 502 503 void SimpleCompPolicy::method_back_branch_event(const methodHandle& m, int bci, JavaThread* thread) { 504 const int comp_level = CompLevel_highest_tier; 505 const int hot_count = m->backedge_count(); 506 507 if (is_compilation_enabled() && can_be_osr_compiled(m, comp_level)) { 508 CompileBroker::compile_method(m, bci, comp_level, m, hot_count, CompileTask::Reason_BackedgeCount, thread); 509 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(bci, comp_level, true));) 510 } 511 } 512 // StackWalkCompPolicy - walk up stack to find a suitable method to compile 513 514 #ifdef COMPILER2 515 const char* StackWalkCompPolicy::_msg = NULL; 516 517 518 // Consider m for compilation 519 void StackWalkCompPolicy::method_invocation_event(const methodHandle& m, JavaThread* thread) { 520 const int comp_level = CompLevel_highest_tier; 521 const int hot_count = m->invocation_count(); 522 reset_counter_for_invocation_event(m); 523 524 if (is_compilation_enabled() && m->code() == NULL && can_be_compiled(m, comp_level)) { 525 ResourceMark rm(thread); 526 frame fr = thread->last_frame(); 527 assert(fr.is_interpreted_frame(), "must be interpreted"); 528 assert(fr.interpreter_frame_method() == m(), "bad method"); 529 530 if (TraceCompilationPolicy) { 531 tty->print("method invocation trigger: "); 532 m->print_short_name(tty); 533 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", p2i((address)m()), m->code_size()); 534 } 535 RegisterMap reg_map(thread, false); 536 javaVFrame* triggerVF = thread->last_java_vframe(®_map); 537 // triggerVF is the frame that triggered its counter 538 RFrame* first = new InterpretedRFrame(triggerVF->fr(), thread, m()); 539 540 if (first->top_method()->code() != NULL) { 541 // called obsolete method/nmethod -- no need to recompile 542 if (TraceCompilationPolicy) tty->print_cr(" --> " INTPTR_FORMAT, p2i(first->top_method()->code())); 543 } else { 544 if (TimeCompilationPolicy) accumulated_time()->start(); 545 GrowableArray<RFrame*>* stack = new GrowableArray<RFrame*>(50); 546 stack->push(first); 547 RFrame* top = findTopInlinableFrame(stack); 548 if (TimeCompilationPolicy) accumulated_time()->stop(); 549 assert(top != NULL, "findTopInlinableFrame returned null"); 550 if (TraceCompilationPolicy) top->print(); 551 CompileBroker::compile_method(top->top_method(), InvocationEntryBci, comp_level, 552 m, hot_count, CompileTask::Reason_InvocationCount, thread); 553 } 554 } 555 } 556 557 void StackWalkCompPolicy::method_back_branch_event(const methodHandle& m, int bci, JavaThread* thread) { 558 const int comp_level = CompLevel_highest_tier; 559 const int hot_count = m->backedge_count(); 560 561 if (is_compilation_enabled() && can_be_osr_compiled(m, comp_level)) { 562 CompileBroker::compile_method(m, bci, comp_level, m, hot_count, CompileTask::Reason_BackedgeCount, thread); 563 NOT_PRODUCT(trace_osr_completion(m->lookup_osr_nmethod_for(bci, comp_level, true));) 564 } 565 } 566 567 RFrame* StackWalkCompPolicy::findTopInlinableFrame(GrowableArray<RFrame*>* stack) { 568 // go up the stack until finding a frame that (probably) won't be inlined 569 // into its caller 570 RFrame* current = stack->at(0); // current choice for stopping 571 assert( current && !current->is_compiled(), "" ); 572 const char* msg = NULL; 573 574 while (1) { 575 576 // before going up the stack further, check if doing so would get us into 577 // compiled code 578 RFrame* next = senderOf(current, stack); 579 if( !next ) // No next frame up the stack? 580 break; // Then compile with current frame 581 582 Method* m = current->top_method(); 583 Method* next_m = next->top_method(); 584 585 if (TraceCompilationPolicy && Verbose) { 586 tty->print("[caller: "); 587 next_m->print_short_name(tty); 588 tty->print("] "); 589 } 590 591 if( !Inline ) { // Inlining turned off 592 msg = "Inlining turned off"; 593 break; 594 } 595 if (next_m->is_not_compilable()) { // Did fail to compile this before/ 596 msg = "caller not compilable"; 597 break; 598 } 599 if (next->num() > MaxRecompilationSearchLength) { 600 // don't go up too high when searching for recompilees 601 msg = "don't go up any further: > MaxRecompilationSearchLength"; 602 break; 603 } 604 if (next->distance() > MaxInterpretedSearchLength) { 605 // don't go up too high when searching for recompilees 606 msg = "don't go up any further: next > MaxInterpretedSearchLength"; 607 break; 608 } 609 // Compiled frame above already decided not to inline; 610 // do not recompile him. 611 if (next->is_compiled()) { 612 msg = "not going up into optimized code"; 613 break; 614 } 615 616 // Interpreted frame above us was already compiled. Do not force 617 // a recompile, although if the frame above us runs long enough an 618 // OSR might still happen. 619 if( current->is_interpreted() && next_m->has_compiled_code() ) { 620 msg = "not going up -- already compiled caller"; 621 break; 622 } 623 624 // Compute how frequent this call site is. We have current method 'm'. 625 // We know next method 'next_m' is interpreted. Find the call site and 626 // check the various invocation counts. 627 int invcnt = 0; // Caller counts 628 if (ProfileInterpreter) { 629 invcnt = next_m->interpreter_invocation_count(); 630 } 631 int cnt = 0; // Call site counts 632 if (ProfileInterpreter && next_m->method_data() != NULL) { 633 ResourceMark rm; 634 int bci = next->top_vframe()->bci(); 635 ProfileData* data = next_m->method_data()->bci_to_data(bci); 636 if (data != NULL && data->is_CounterData()) 637 cnt = data->as_CounterData()->count(); 638 } 639 640 // Caller counts / call-site counts; i.e. is this call site 641 // a hot call site for method next_m? 642 int freq = (invcnt) ? cnt/invcnt : cnt; 643 644 // Check size and frequency limits 645 if ((msg = shouldInline(m, freq, cnt)) != NULL) { 646 break; 647 } 648 // Check inlining negative tests 649 if ((msg = shouldNotInline(m)) != NULL) { 650 break; 651 } 652 653 654 // If the caller method is too big or something then we do not want to 655 // compile it just to inline a method 656 if (!can_be_compiled(next_m, CompLevel_any)) { 657 msg = "caller cannot be compiled"; 658 break; 659 } 660 661 if( next_m->name() == vmSymbols::class_initializer_name() ) { 662 msg = "do not compile class initializer (OSR ok)"; 663 break; 664 } 665 666 if (TraceCompilationPolicy && Verbose) { 667 tty->print("\n\t check caller: "); 668 next_m->print_short_name(tty); 669 tty->print(" ( interpreted " INTPTR_FORMAT ", size=%d ) ", p2i((address)next_m), next_m->code_size()); 670 } 671 672 current = next; 673 } 674 675 assert( !current || !current->is_compiled(), "" ); 676 677 if (TraceCompilationPolicy && msg) tty->print("(%s)\n", msg); 678 679 return current; 680 } 681 682 RFrame* StackWalkCompPolicy::senderOf(RFrame* rf, GrowableArray<RFrame*>* stack) { 683 RFrame* sender = rf->caller(); 684 if (sender && sender->num() == stack->length()) stack->push(sender); 685 return sender; 686 } 687 688 689 const char* StackWalkCompPolicy::shouldInline(const methodHandle& m, float freq, int cnt) { 690 // Allows targeted inlining 691 // positive filter: should send be inlined? returns NULL (--> yes) 692 // or rejection msg 693 int max_size = MaxInlineSize; 694 int cost = m->code_size(); 695 696 // Check for too many throws (and not too huge) 697 if (m->interpreter_throwout_count() > InlineThrowCount && cost < InlineThrowMaxSize ) { 698 return NULL; 699 } 700 701 // bump the max size if the call is frequent 702 if ((freq >= InlineFrequencyRatio) || (cnt >= InlineFrequencyCount)) { 703 if (TraceFrequencyInlining) { 704 tty->print("(Inlined frequent method)\n"); 705 m->print(); 706 } 707 max_size = FreqInlineSize; 708 } 709 if (cost > max_size) { 710 return (_msg = "too big"); 711 } 712 return NULL; 713 } 714 715 716 const char* StackWalkCompPolicy::shouldNotInline(const methodHandle& m) { 717 // negative filter: should send NOT be inlined? returns NULL (--> inline) or rejection msg 718 if (m->is_abstract()) return (_msg = "abstract method"); 719 // note: we allow ik->is_abstract() 720 if (!m->method_holder()->is_initialized()) return (_msg = "method holder not initialized"); 721 if (m->is_native()) return (_msg = "native method"); 722 CompiledMethod* m_code = m->code(); 723 if (m_code != NULL && m_code->code_size() > InlineSmallCode) 724 return (_msg = "already compiled into a big method"); 725 726 // use frequency-based objections only for non-trivial methods 727 if (m->code_size() <= MaxTrivialSize) return NULL; 728 if (UseInterpreter) { // don't use counts with -Xcomp 729 if ((m->code() == NULL) && m->was_never_executed()) return (_msg = "never executed"); 730 if (!m->was_executed_more_than(MIN2(MinInliningThreshold, CompileThreshold >> 1))) return (_msg = "executed < MinInliningThreshold times"); 731 } 732 if (Method::has_unloaded_classes_in_signature(m, JavaThread::current())) return (_msg = "unloaded signature classes"); 733 734 return NULL; 735 } 736 737 738 739 #endif // COMPILER2