1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_RUNTIME_INSTRUMENTATION_H_ 18 #define ART_RUNTIME_INSTRUMENTATION_H_ 19 20 #include <stdint.h> 21 22 #include <functional> 23 #include <list> 24 #include <memory> 25 #include <optional> 26 #include <unordered_set> 27 28 #include "arch/instruction_set.h" 29 #include "base/enums.h" 30 #include "base/locks.h" 31 #include "base/macros.h" 32 #include "base/safe_map.h" 33 #include "gc_root.h" 34 #include "offsets.h" 35 36 namespace art { 37 namespace mirror { 38 class Class; 39 class Object; 40 class Throwable; 41 } // namespace mirror 42 class ArtField; 43 class ArtMethod; 44 template <typename T> class Handle; 45 template <typename T> class MutableHandle; 46 struct NthCallerVisitor; 47 union JValue; 48 class SHARED_LOCKABLE ReaderWriterMutex; 49 class ShadowFrame; 50 class Thread; 51 enum class DeoptimizationMethodType; 52 53 namespace instrumentation { 54 55 56 // Do we want to deoptimize for method entry and exit listeners or just try to intercept 57 // invocations? Deoptimization forces all code to run in the interpreter and considerably hurts the 58 // application's performance. 59 static constexpr bool kDeoptimizeForAccurateMethodEntryExitListeners = true; 60 61 // an optional frame is either Some(const ShadowFrame& current_frame) or None depending on if the 62 // method being exited has a shadow-frame associed with the current stack frame. In cases where 63 // there is no shadow-frame associated with this stack frame this will be None. 64 using OptionalFrame = std::optional<std::reference_wrapper<const ShadowFrame>>; 65 66 // Instrumentation event listener API. Registered listeners will get the appropriate call back for 67 // the events they are listening for. The call backs supply the thread, method and dex_pc the event 68 // occurred upon. The thread may or may not be Thread::Current(). 69 struct InstrumentationListener { InstrumentationListenerInstrumentationListener70 InstrumentationListener() {} ~InstrumentationListenerInstrumentationListener71 virtual ~InstrumentationListener() {} 72 73 // Call-back for when a method is entered. 74 virtual void MethodEntered(Thread* thread, ArtMethod* method) 75 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 76 77 virtual void MethodExited(Thread* thread, 78 ArtMethod* method, 79 OptionalFrame frame, 80 MutableHandle<mirror::Object>& return_value) 81 REQUIRES_SHARED(Locks::mutator_lock_); 82 83 // Call-back for when a method is exited. The implementor should either handler-ize the return 84 // value (if appropriate) or use the alternate MethodExited callback instead if they need to 85 // go through a suspend point. 86 virtual void MethodExited(Thread* thread, 87 ArtMethod* method, 88 OptionalFrame frame, 89 JValue& return_value) 90 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 91 92 // Call-back for when a method is popped due to an exception throw. A method will either cause a 93 // MethodExited call-back or a MethodUnwind call-back when its activation is removed. 94 virtual void MethodUnwind(Thread* thread, 95 Handle<mirror::Object> this_object, 96 ArtMethod* method, 97 uint32_t dex_pc) 98 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 99 100 // Call-back for when the dex pc moves in a method. 101 virtual void DexPcMoved(Thread* thread, 102 Handle<mirror::Object> this_object, 103 ArtMethod* method, 104 uint32_t new_dex_pc) 105 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 106 107 // Call-back for when we read from a field. 108 virtual void FieldRead(Thread* thread, 109 Handle<mirror::Object> this_object, 110 ArtMethod* method, 111 uint32_t dex_pc, 112 ArtField* field) = 0; 113 114 virtual void FieldWritten(Thread* thread, 115 Handle<mirror::Object> this_object, 116 ArtMethod* method, 117 uint32_t dex_pc, 118 ArtField* field, 119 Handle<mirror::Object> field_value) 120 REQUIRES_SHARED(Locks::mutator_lock_); 121 122 // Call-back for when we write into a field. 123 virtual void FieldWritten(Thread* thread, 124 Handle<mirror::Object> this_object, 125 ArtMethod* method, 126 uint32_t dex_pc, 127 ArtField* field, 128 const JValue& field_value) 129 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 130 131 // Call-back when an exception is thrown. 132 virtual void ExceptionThrown(Thread* thread, 133 Handle<mirror::Throwable> exception_object) 134 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 135 136 // Call-back when an exception is caught/handled by java code. 137 virtual void ExceptionHandled(Thread* thread, Handle<mirror::Throwable> exception_object) 138 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 139 140 // Call-back for when we execute a branch. 141 virtual void Branch(Thread* thread, 142 ArtMethod* method, 143 uint32_t dex_pc, 144 int32_t dex_pc_offset) 145 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 146 147 // Call-back when a shadow_frame with the needs_notify_pop_ boolean set is popped off the stack by 148 // either return or exceptions. Normally instrumentation listeners should ensure that there are 149 // shadow-frames by deoptimizing stacks. 150 virtual void WatchedFramePop(Thread* thread ATTRIBUTE_UNUSED, 151 const ShadowFrame& frame ATTRIBUTE_UNUSED) 152 REQUIRES_SHARED(Locks::mutator_lock_) = 0; 153 }; 154 155 class Instrumentation; 156 // A helper to send instrumentation events while popping the stack in a safe way. 157 class InstrumentationStackPopper { 158 public: 159 explicit InstrumentationStackPopper(Thread* self); 160 ~InstrumentationStackPopper() REQUIRES_SHARED(Locks::mutator_lock_); 161 162 // Increase the number of frames being popped up to `stack_pointer`. Return true if the 163 // frames were popped without any exceptions, false otherwise. The exception that caused 164 // the pop is 'exception'. 165 bool PopFramesTo(uintptr_t stack_pointer, /*in-out*/MutableHandle<mirror::Throwable>& exception) 166 REQUIRES_SHARED(Locks::mutator_lock_); 167 168 private: 169 Thread* self_; 170 Instrumentation* instrumentation_; 171 // The stack pointer limit for frames to pop. 172 uintptr_t pop_until_; 173 }; 174 175 // Instrumentation is a catch-all for when extra information is required from the runtime. The 176 // typical use for instrumentation is for profiling and debugging. Instrumentation may add stubs 177 // to method entry and exit, it may also force execution to be switched to the interpreter and 178 // trigger deoptimization. 179 class Instrumentation { 180 public: 181 enum InstrumentationEvent { 182 kMethodEntered = 0x1, 183 kMethodExited = 0x2, 184 kMethodUnwind = 0x4, 185 kDexPcMoved = 0x8, 186 kFieldRead = 0x10, 187 kFieldWritten = 0x20, 188 kExceptionThrown = 0x40, 189 kBranch = 0x80, 190 kWatchedFramePop = 0x200, 191 kExceptionHandled = 0x400, 192 }; 193 194 enum class InstrumentationLevel { 195 kInstrumentNothing, // execute without instrumentation 196 kInstrumentWithInstrumentationStubs, // execute with instrumentation entry/exit stubs 197 kInstrumentWithInterpreter // execute with interpreter 198 }; 199 200 Instrumentation(); 201 NeedsEntryExitHooksOffset()202 static constexpr MemberOffset NeedsEntryExitHooksOffset() { 203 // Assert that instrumentation_stubs_installed_ is 8bits wide. If the size changes 204 // update the compare instructions in the code generator when generating checks for 205 // MethodEntryExitHooks. 206 static_assert(sizeof(instrumentation_stubs_installed_) == 1, 207 "instrumentation_stubs_installed_ isn't expected size"); 208 return MemberOffset(OFFSETOF_MEMBER(Instrumentation, instrumentation_stubs_installed_)); 209 } 210 211 // Add a listener to be notified of the masked together sent of instrumentation events. This 212 // suspend the runtime to install stubs. You are expected to hold the mutator lock as a proxy 213 // for saying you should have suspended all threads (installing stubs while threads are running 214 // will break). 215 void AddListener(InstrumentationListener* listener, uint32_t events) 216 REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::classlinker_classes_lock_); 217 218 // Removes a listener possibly removing instrumentation stubs. 219 void RemoveListener(InstrumentationListener* listener, uint32_t events) 220 REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_, !Locks::classlinker_classes_lock_); 221 222 // Calls UndeoptimizeEverything which may visit class linker classes through ConfigureStubs. 223 void DisableDeoptimization(const char* key) 224 REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_) 225 REQUIRES(!GetDeoptimizedMethodsLock()); 226 AreAllMethodsDeoptimized()227 bool AreAllMethodsDeoptimized() const { 228 return InterpreterStubsInstalled(); 229 } 230 bool ShouldNotifyMethodEnterExitEvents() const REQUIRES_SHARED(Locks::mutator_lock_); 231 232 // Executes everything with interpreter. 233 void DeoptimizeEverything(const char* key) 234 REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_) 235 REQUIRES(!Locks::thread_list_lock_, 236 !Locks::classlinker_classes_lock_, 237 !GetDeoptimizedMethodsLock()); 238 239 // Executes everything with compiled code (or interpreter if there is no code). May visit class 240 // linker classes through ConfigureStubs. 241 void UndeoptimizeEverything(const char* key) 242 REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_) 243 REQUIRES(!Locks::thread_list_lock_, 244 !Locks::classlinker_classes_lock_, 245 !GetDeoptimizedMethodsLock()); 246 247 // Deoptimize a method by forcing its execution with the interpreter. Nevertheless, a static 248 // method (except a class initializer) set to the resolution trampoline will be deoptimized only 249 // once its declaring class is initialized. 250 void Deoptimize(ArtMethod* method) 251 REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_, !GetDeoptimizedMethodsLock()); 252 253 // Undeoptimze the method by restoring its entrypoints. Nevertheless, a static method 254 // (except a class initializer) set to the resolution trampoline will be updated only once its 255 // declaring class is initialized. 256 void Undeoptimize(ArtMethod* method) 257 REQUIRES(Locks::mutator_lock_, !Locks::thread_list_lock_, !GetDeoptimizedMethodsLock()); 258 259 // Indicates whether the method has been deoptimized so it is executed with the interpreter. 260 bool IsDeoptimized(ArtMethod* method) 261 REQUIRES(!GetDeoptimizedMethodsLock()) REQUIRES_SHARED(Locks::mutator_lock_); 262 263 // Indicates if any method needs to be deoptimized. This is used to avoid walking the stack to 264 // determine if a deoptimization is required. 265 bool IsDeoptimizedMethodsEmpty() const 266 REQUIRES(!GetDeoptimizedMethodsLock()) REQUIRES_SHARED(Locks::mutator_lock_); 267 268 // Enable method tracing by installing instrumentation entry/exit stubs or interpreter. 269 void EnableMethodTracing(const char* key, 270 bool needs_interpreter = kDeoptimizeForAccurateMethodEntryExitListeners) 271 REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_) 272 REQUIRES(!Locks::thread_list_lock_, 273 !Locks::classlinker_classes_lock_, 274 !GetDeoptimizedMethodsLock()); 275 276 // Disable method tracing by uninstalling instrumentation entry/exit stubs or interpreter. 277 void DisableMethodTracing(const char* key) 278 REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_) 279 REQUIRES(!Locks::thread_list_lock_, 280 !Locks::classlinker_classes_lock_, 281 !GetDeoptimizedMethodsLock()); 282 283 284 void InstrumentQuickAllocEntryPoints() REQUIRES(!Locks::instrument_entrypoints_lock_); 285 void UninstrumentQuickAllocEntryPoints() REQUIRES(!Locks::instrument_entrypoints_lock_); 286 void InstrumentQuickAllocEntryPointsLocked() 287 REQUIRES(Locks::instrument_entrypoints_lock_, !Locks::thread_list_lock_, 288 !Locks::runtime_shutdown_lock_); 289 void UninstrumentQuickAllocEntryPointsLocked() 290 REQUIRES(Locks::instrument_entrypoints_lock_, !Locks::thread_list_lock_, 291 !Locks::runtime_shutdown_lock_); 292 void ResetQuickAllocEntryPoints() REQUIRES(Locks::runtime_shutdown_lock_); 293 294 // Returns a string representation of the given entry point. 295 static std::string EntryPointString(const void* code); 296 297 // Initialize the entrypoint of the method .`aot_code` is the AOT code. 298 void InitializeMethodsCode(ArtMethod* method, const void* aot_code) 299 REQUIRES_SHARED(Locks::mutator_lock_); 300 301 // Update the code of a method respecting any installed stubs. 302 void UpdateMethodsCode(ArtMethod* method, const void* new_code) 303 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!GetDeoptimizedMethodsLock()); 304 305 // Update the code of a native method to a JITed stub. 306 void UpdateNativeMethodsCodeToJitCode(ArtMethod* method, const void* new_code) 307 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!GetDeoptimizedMethodsLock()); 308 309 // Return the code that we can execute for an invoke including from the JIT. 310 const void* GetCodeForInvoke(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_); 311 312 // Return the code that we can execute considering the current instrumentation level. 313 // If interpreter stubs are installed return interpreter bridge. If the entry exit stubs 314 // are installed return an instrumentation entry point. Otherwise, return the code that 315 // can be executed including from the JIT. 316 const void* GetMaybeInstrumentedCodeForInvoke(ArtMethod* method) 317 REQUIRES_SHARED(Locks::mutator_lock_); 318 ForceInterpretOnly()319 void ForceInterpretOnly() { 320 forced_interpret_only_ = true; 321 } 322 EntryExitStubsInstalled()323 bool EntryExitStubsInstalled() const { 324 return instrumentation_level_ == InstrumentationLevel::kInstrumentWithInstrumentationStubs || 325 instrumentation_level_ == InstrumentationLevel::kInstrumentWithInterpreter; 326 } 327 InterpreterStubsInstalled()328 bool InterpreterStubsInstalled() const { 329 return instrumentation_level_ == InstrumentationLevel::kInstrumentWithInterpreter; 330 } 331 332 // Called by ArtMethod::Invoke to determine dispatch mechanism. InterpretOnly()333 bool InterpretOnly() const { 334 return forced_interpret_only_ || InterpreterStubsInstalled(); 335 } 336 bool InterpretOnly(ArtMethod* method) REQUIRES_SHARED(Locks::mutator_lock_); 337 IsForcedInterpretOnly()338 bool IsForcedInterpretOnly() const { 339 return forced_interpret_only_; 340 } 341 AreExitStubsInstalled()342 bool AreExitStubsInstalled() const { 343 return instrumentation_stubs_installed_; 344 } 345 HasMethodEntryListeners()346 bool HasMethodEntryListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 347 return have_method_entry_listeners_; 348 } 349 HasMethodExitListeners()350 bool HasMethodExitListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 351 return have_method_exit_listeners_; 352 } 353 HasMethodUnwindListeners()354 bool HasMethodUnwindListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 355 return have_method_unwind_listeners_; 356 } 357 HasDexPcListeners()358 bool HasDexPcListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 359 return have_dex_pc_listeners_; 360 } 361 HasFieldReadListeners()362 bool HasFieldReadListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 363 return have_field_read_listeners_; 364 } 365 HasFieldWriteListeners()366 bool HasFieldWriteListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 367 return have_field_write_listeners_; 368 } 369 HasExceptionThrownListeners()370 bool HasExceptionThrownListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 371 return have_exception_thrown_listeners_; 372 } 373 HasBranchListeners()374 bool HasBranchListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 375 return have_branch_listeners_; 376 } 377 HasWatchedFramePopListeners()378 bool HasWatchedFramePopListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 379 return have_watched_frame_pop_listeners_; 380 } 381 HasExceptionHandledListeners()382 bool HasExceptionHandledListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 383 return have_exception_handled_listeners_; 384 } 385 NeedsSlowInterpreterForListeners()386 bool NeedsSlowInterpreterForListeners() const REQUIRES_SHARED(Locks::mutator_lock_) { 387 return have_field_read_listeners_ || 388 have_field_write_listeners_ || 389 have_watched_frame_pop_listeners_ || 390 have_exception_handled_listeners_; 391 } 392 393 // Inform listeners that a method has been entered. A dex PC is provided as we may install 394 // listeners into executing code and get method enter events for methods already on the stack. MethodEnterEvent(Thread * thread,ArtMethod * method)395 void MethodEnterEvent(Thread* thread, ArtMethod* method) const 396 REQUIRES_SHARED(Locks::mutator_lock_) { 397 if (UNLIKELY(HasMethodEntryListeners())) { 398 MethodEnterEventImpl(thread, method); 399 } 400 } 401 402 // Inform listeners that a method has been exited. 403 template<typename T> MethodExitEvent(Thread * thread,ArtMethod * method,OptionalFrame frame,T & return_value)404 void MethodExitEvent(Thread* thread, 405 ArtMethod* method, 406 OptionalFrame frame, 407 T& return_value) const 408 REQUIRES_SHARED(Locks::mutator_lock_) { 409 if (UNLIKELY(HasMethodExitListeners())) { 410 MethodExitEventImpl(thread, method, frame, return_value); 411 } 412 } 413 414 // Inform listeners that a method has been exited due to an exception. 415 void MethodUnwindEvent(Thread* thread, 416 ObjPtr<mirror::Object> this_object, 417 ArtMethod* method, 418 uint32_t dex_pc) const 419 REQUIRES_SHARED(Locks::mutator_lock_); 420 421 // Inform listeners that the dex pc has moved (only supported by the interpreter). DexPcMovedEvent(Thread * thread,ObjPtr<mirror::Object> this_object,ArtMethod * method,uint32_t dex_pc)422 void DexPcMovedEvent(Thread* thread, 423 ObjPtr<mirror::Object> this_object, 424 ArtMethod* method, 425 uint32_t dex_pc) const 426 REQUIRES_SHARED(Locks::mutator_lock_) { 427 if (UNLIKELY(HasDexPcListeners())) { 428 DexPcMovedEventImpl(thread, this_object, method, dex_pc); 429 } 430 } 431 432 // Inform listeners that a branch has been taken (only supported by the interpreter). Branch(Thread * thread,ArtMethod * method,uint32_t dex_pc,int32_t offset)433 void Branch(Thread* thread, ArtMethod* method, uint32_t dex_pc, int32_t offset) const 434 REQUIRES_SHARED(Locks::mutator_lock_) { 435 if (UNLIKELY(HasBranchListeners())) { 436 BranchImpl(thread, method, dex_pc, offset); 437 } 438 } 439 440 // Inform listeners that we read a field (only supported by the interpreter). FieldReadEvent(Thread * thread,ObjPtr<mirror::Object> this_object,ArtMethod * method,uint32_t dex_pc,ArtField * field)441 void FieldReadEvent(Thread* thread, 442 ObjPtr<mirror::Object> this_object, 443 ArtMethod* method, 444 uint32_t dex_pc, 445 ArtField* field) const 446 REQUIRES_SHARED(Locks::mutator_lock_) { 447 if (UNLIKELY(HasFieldReadListeners())) { 448 FieldReadEventImpl(thread, this_object, method, dex_pc, field); 449 } 450 } 451 452 // Inform listeners that we write a field (only supported by the interpreter). FieldWriteEvent(Thread * thread,ObjPtr<mirror::Object> this_object,ArtMethod * method,uint32_t dex_pc,ArtField * field,const JValue & field_value)453 void FieldWriteEvent(Thread* thread, 454 ObjPtr<mirror::Object> this_object, 455 ArtMethod* method, 456 uint32_t dex_pc, 457 ArtField* field, 458 const JValue& field_value) const 459 REQUIRES_SHARED(Locks::mutator_lock_) { 460 if (UNLIKELY(HasFieldWriteListeners())) { 461 FieldWriteEventImpl(thread, this_object, method, dex_pc, field, field_value); 462 } 463 } 464 465 // Inform listeners that a branch has been taken (only supported by the interpreter). WatchedFramePopped(Thread * thread,const ShadowFrame & frame)466 void WatchedFramePopped(Thread* thread, const ShadowFrame& frame) const 467 REQUIRES_SHARED(Locks::mutator_lock_) { 468 if (UNLIKELY(HasWatchedFramePopListeners())) { 469 WatchedFramePopImpl(thread, frame); 470 } 471 } 472 473 // Inform listeners that an exception was thrown. 474 void ExceptionThrownEvent(Thread* thread, ObjPtr<mirror::Throwable> exception_object) const 475 REQUIRES_SHARED(Locks::mutator_lock_); 476 477 // Inform listeners that an exception has been handled. This is not sent for native code or for 478 // exceptions which reach the end of the thread's stack. 479 void ExceptionHandledEvent(Thread* thread, ObjPtr<mirror::Throwable> exception_object) const 480 REQUIRES_SHARED(Locks::mutator_lock_); 481 482 JValue GetReturnValue(Thread* self, 483 ArtMethod* method, 484 bool* is_ref, 485 uint64_t* gpr_result, 486 uint64_t* fpr_result) REQUIRES_SHARED(Locks::mutator_lock_); 487 bool ShouldDeoptimizeMethod(Thread* self, const NthCallerVisitor& visitor) 488 REQUIRES_SHARED(Locks::mutator_lock_); 489 490 // Called when an instrumented method is entered. The intended link register (lr) is saved so 491 // that returning causes a branch to the method exit stub. Generates method enter events. 492 void PushInstrumentationStackFrame(Thread* self, 493 ObjPtr<mirror::Object> this_object, 494 ArtMethod* method, 495 uintptr_t stack_pointer, 496 uintptr_t lr, 497 bool interpreter_entry) 498 REQUIRES_SHARED(Locks::mutator_lock_); 499 500 DeoptimizationMethodType GetDeoptimizationMethodType(ArtMethod* method) 501 REQUIRES_SHARED(Locks::mutator_lock_); 502 503 // Called when an instrumented method is exited. Removes the pushed instrumentation frame 504 // returning the intended link register. Generates method exit events. The gpr_result and 505 // fpr_result pointers are pointers to the locations where the integer/pointer and floating point 506 // result values of the function are stored. Both pointers must always be valid but the values 507 // held there will only be meaningful if interpreted as the appropriate type given the function 508 // being returned from. 509 TwoWordReturn PopInstrumentationStackFrame(Thread* self, 510 uintptr_t* return_pc_addr, 511 uint64_t* gpr_result, 512 uint64_t* fpr_result) 513 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!GetDeoptimizedMethodsLock()); 514 515 // Pops nframes instrumentation frames from the current thread. Returns the return pc for the last 516 // instrumentation frame that's popped. 517 uintptr_t PopFramesForDeoptimization(Thread* self, uintptr_t stack_pointer) const 518 REQUIRES_SHARED(Locks::mutator_lock_); 519 520 // Call back for configure stubs. 521 void InstallStubsForClass(ObjPtr<mirror::Class> klass) REQUIRES_SHARED(Locks::mutator_lock_) 522 REQUIRES(!GetDeoptimizedMethodsLock()); 523 524 void InstallStubsForMethod(ArtMethod* method) 525 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!GetDeoptimizedMethodsLock()); 526 527 // Install instrumentation exit stub on every method of the stack of the given thread. 528 // This is used by: 529 // - the debugger to cause a deoptimization of the all frames in thread's stack (for 530 // example, after updating local variables) 531 // - to call method entry / exit hooks for tracing. For this we instrument 532 // the stack frame to run entry / exit hooks but we don't need to deoptimize. 533 // deopt_all_frames indicates whether the frames need to deoptimize or not. 534 void InstrumentThreadStack(Thread* thread, bool deopt_all_frames) REQUIRES(Locks::mutator_lock_); 535 536 // Force all currently running frames to be deoptimized back to interpreter. This should only be 537 // used in cases where basically all compiled code has been invalidated. 538 void DeoptimizeAllThreadFrames() REQUIRES(art::Locks::mutator_lock_); 539 540 static size_t ComputeFrameId(Thread* self, 541 size_t frame_depth, 542 size_t inlined_frames_before_frame) 543 REQUIRES_SHARED(Locks::mutator_lock_); 544 545 // Does not hold lock, used to check if someone changed from not instrumented to instrumented 546 // during a GC suspend point. AllocEntrypointsInstrumented()547 bool AllocEntrypointsInstrumented() const REQUIRES_SHARED(Locks::mutator_lock_) { 548 return alloc_entrypoints_instrumented_; 549 } 550 551 InstrumentationLevel GetCurrentInstrumentationLevel() const; 552 553 private: 554 // Returns true if moving to the given instrumentation level requires the installation of stubs. 555 // False otherwise. 556 bool RequiresInstrumentationInstallation(InstrumentationLevel new_level) const; 557 558 // Returns true if we need entry exit stub to call entry hooks. JITed code 559 // directly call entry / exit hooks and don't need the stub. 560 static bool CodeNeedsEntryExitStub(const void* code, ArtMethod* method) 561 REQUIRES_SHARED(Locks::mutator_lock_); 562 563 // Update the current instrumentation_level_. 564 void UpdateInstrumentationLevel(InstrumentationLevel level); 565 566 // Does the job of installing or removing instrumentation code within methods. 567 // In order to support multiple clients using instrumentation at the same time, 568 // the caller must pass a unique key (a string) identifying it so we remind which 569 // instrumentation level it needs. Therefore the current instrumentation level 570 // becomes the highest instrumentation level required by a client. 571 void ConfigureStubs(const char* key, InstrumentationLevel desired_instrumentation_level) 572 REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_) 573 REQUIRES(!GetDeoptimizedMethodsLock(), 574 !Locks::thread_list_lock_, 575 !Locks::classlinker_classes_lock_); 576 void UpdateStubs() REQUIRES(Locks::mutator_lock_, Roles::uninterruptible_) 577 REQUIRES(!GetDeoptimizedMethodsLock(), 578 !Locks::thread_list_lock_, 579 !Locks::classlinker_classes_lock_); 580 581 // If there are no pending deoptimizations restores the stack to the normal state by updating the 582 // return pcs to actual return addresses from the instrumentation stack and clears the 583 // instrumentation stack. 584 void MaybeRestoreInstrumentationStack() REQUIRES(Locks::mutator_lock_); 585 586 // No thread safety analysis to get around SetQuickAllocEntryPointsInstrumented requiring 587 // exclusive access to mutator lock which you can't get if the runtime isn't started. 588 void SetEntrypointsInstrumented(bool instrumented) NO_THREAD_SAFETY_ANALYSIS; 589 590 void MethodEnterEventImpl(Thread* thread, ArtMethod* method) const 591 REQUIRES_SHARED(Locks::mutator_lock_); 592 template <typename T> 593 void MethodExitEventImpl(Thread* thread, 594 ArtMethod* method, 595 OptionalFrame frame, 596 T& return_value) const 597 REQUIRES_SHARED(Locks::mutator_lock_); 598 void DexPcMovedEventImpl(Thread* thread, 599 ObjPtr<mirror::Object> this_object, 600 ArtMethod* method, 601 uint32_t dex_pc) const 602 REQUIRES_SHARED(Locks::mutator_lock_); 603 void BranchImpl(Thread* thread, ArtMethod* method, uint32_t dex_pc, int32_t offset) const 604 REQUIRES_SHARED(Locks::mutator_lock_); 605 void WatchedFramePopImpl(Thread* thread, const ShadowFrame& frame) const 606 REQUIRES_SHARED(Locks::mutator_lock_); 607 void FieldReadEventImpl(Thread* thread, 608 ObjPtr<mirror::Object> this_object, 609 ArtMethod* method, 610 uint32_t dex_pc, 611 ArtField* field) const 612 REQUIRES_SHARED(Locks::mutator_lock_); 613 void FieldWriteEventImpl(Thread* thread, 614 ObjPtr<mirror::Object> this_object, 615 ArtMethod* method, 616 uint32_t dex_pc, 617 ArtField* field, 618 const JValue& field_value) const 619 REQUIRES_SHARED(Locks::mutator_lock_); 620 621 // Read barrier-aware utility functions for accessing deoptimized_methods_ 622 bool AddDeoptimizedMethod(ArtMethod* method) 623 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(GetDeoptimizedMethodsLock()); 624 bool IsDeoptimizedMethod(ArtMethod* method) 625 REQUIRES_SHARED(Locks::mutator_lock_, GetDeoptimizedMethodsLock()); 626 bool RemoveDeoptimizedMethod(ArtMethod* method) 627 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(GetDeoptimizedMethodsLock()); 628 ArtMethod* BeginDeoptimizedMethod() 629 REQUIRES_SHARED(Locks::mutator_lock_, GetDeoptimizedMethodsLock()); 630 bool IsDeoptimizedMethodsEmptyLocked() const 631 REQUIRES_SHARED(Locks::mutator_lock_, GetDeoptimizedMethodsLock()); 632 void UpdateMethodsCodeImpl(ArtMethod* method, const void* new_code) 633 REQUIRES_SHARED(Locks::mutator_lock_) REQUIRES(!GetDeoptimizedMethodsLock()); 634 GetDeoptimizedMethodsLock()635 ReaderWriterMutex* GetDeoptimizedMethodsLock() const { 636 return deoptimized_methods_lock_.get(); 637 } 638 639 // A counter that's incremented every time a DeoptimizeAllFrames. We check each 640 // InstrumentationStackFrames creation id against this number and if they differ we deopt even if 641 // we could otherwise continue running. 642 uint64_t current_force_deopt_id_ GUARDED_BY(Locks::mutator_lock_); 643 644 // Have we hijacked ArtMethod::code_ so that it calls instrumentation/interpreter code? 645 bool instrumentation_stubs_installed_; 646 647 // The required level of instrumentation. This could be one of the following values: 648 // kInstrumentNothing: no instrumentation support is needed 649 // kInstrumentWithInstrumentationStubs: needs support to call method entry/exit stubs. 650 // kInstrumentWithInterpreter: only execute with interpreter 651 Instrumentation::InstrumentationLevel instrumentation_level_; 652 653 // Did the runtime request we only run in the interpreter? ie -Xint mode. 654 bool forced_interpret_only_; 655 656 // Do we have any listeners for method entry events? Short-cut to avoid taking the 657 // instrumentation_lock_. 658 bool have_method_entry_listeners_ GUARDED_BY(Locks::mutator_lock_); 659 660 // Do we have any listeners for method exit events? Short-cut to avoid taking the 661 // instrumentation_lock_. 662 bool have_method_exit_listeners_ GUARDED_BY(Locks::mutator_lock_); 663 664 // Do we have any listeners for method unwind events? Short-cut to avoid taking the 665 // instrumentation_lock_. 666 bool have_method_unwind_listeners_ GUARDED_BY(Locks::mutator_lock_); 667 668 // Do we have any listeners for dex move events? Short-cut to avoid taking the 669 // instrumentation_lock_. 670 bool have_dex_pc_listeners_ GUARDED_BY(Locks::mutator_lock_); 671 672 // Do we have any listeners for field read events? Short-cut to avoid taking the 673 // instrumentation_lock_. 674 bool have_field_read_listeners_ GUARDED_BY(Locks::mutator_lock_); 675 676 // Do we have any listeners for field write events? Short-cut to avoid taking the 677 // instrumentation_lock_. 678 bool have_field_write_listeners_ GUARDED_BY(Locks::mutator_lock_); 679 680 // Do we have any exception thrown listeners? Short-cut to avoid taking the instrumentation_lock_. 681 bool have_exception_thrown_listeners_ GUARDED_BY(Locks::mutator_lock_); 682 683 // Do we have any frame pop listeners? Short-cut to avoid taking the instrumentation_lock_. 684 bool have_watched_frame_pop_listeners_ GUARDED_BY(Locks::mutator_lock_); 685 686 // Do we have any branch listeners? Short-cut to avoid taking the instrumentation_lock_. 687 bool have_branch_listeners_ GUARDED_BY(Locks::mutator_lock_); 688 689 // Do we have any exception handled listeners? Short-cut to avoid taking the 690 // instrumentation_lock_. 691 bool have_exception_handled_listeners_ GUARDED_BY(Locks::mutator_lock_); 692 693 // Contains the instrumentation level required by each client of the instrumentation identified 694 // by a string key. 695 using InstrumentationLevelTable = SafeMap<const char*, InstrumentationLevel>; 696 InstrumentationLevelTable requested_instrumentation_levels_ GUARDED_BY(Locks::mutator_lock_); 697 698 // The event listeners, written to with the mutator_lock_ exclusively held. 699 // Mutators must be able to iterate over these lists concurrently, that is, with listeners being 700 // added or removed while iterating. The modifying thread holds exclusive lock, 701 // so other threads cannot iterate (i.e. read the data of the list) at the same time but they 702 // do keep iterators that need to remain valid. This is the reason these listeners are std::list 703 // and not for example std::vector: the existing storage for a std::list does not move. 704 // Note that mutators cannot make a copy of these lists before iterating, as the instrumentation 705 // listeners can also be deleted concurrently. 706 // As a result, these lists are never trimmed. That's acceptable given the low number of 707 // listeners we have. 708 std::list<InstrumentationListener*> method_entry_listeners_ GUARDED_BY(Locks::mutator_lock_); 709 std::list<InstrumentationListener*> method_exit_listeners_ GUARDED_BY(Locks::mutator_lock_); 710 std::list<InstrumentationListener*> method_unwind_listeners_ GUARDED_BY(Locks::mutator_lock_); 711 std::list<InstrumentationListener*> branch_listeners_ GUARDED_BY(Locks::mutator_lock_); 712 std::list<InstrumentationListener*> dex_pc_listeners_ GUARDED_BY(Locks::mutator_lock_); 713 std::list<InstrumentationListener*> field_read_listeners_ GUARDED_BY(Locks::mutator_lock_); 714 std::list<InstrumentationListener*> field_write_listeners_ GUARDED_BY(Locks::mutator_lock_); 715 std::list<InstrumentationListener*> exception_thrown_listeners_ GUARDED_BY(Locks::mutator_lock_); 716 std::list<InstrumentationListener*> watched_frame_pop_listeners_ GUARDED_BY(Locks::mutator_lock_); 717 std::list<InstrumentationListener*> exception_handled_listeners_ GUARDED_BY(Locks::mutator_lock_); 718 719 // The set of methods being deoptimized (by the debugger) which must be executed with interpreter 720 // only. 721 mutable std::unique_ptr<ReaderWriterMutex> deoptimized_methods_lock_ BOTTOM_MUTEX_ACQUIRED_AFTER; 722 std::unordered_set<ArtMethod*> deoptimized_methods_ GUARDED_BY(GetDeoptimizedMethodsLock()); 723 724 // Current interpreter handler table. This is updated each time the thread state flags are 725 // modified. 726 727 // Greater than 0 if quick alloc entry points instrumented. 728 size_t quick_alloc_entry_points_instrumentation_counter_; 729 730 // alloc_entrypoints_instrumented_ is only updated with all the threads suspended, this is done 731 // to prevent races with the GC where the GC relies on thread suspension only see 732 // alloc_entrypoints_instrumented_ change during suspend points. 733 bool alloc_entrypoints_instrumented_; 734 735 friend class InstrumentationTest; // For GetCurrentInstrumentationLevel and ConfigureStubs. 736 friend class InstrumentationStackPopper; // For popping instrumentation frames. 737 friend void InstrumentationInstallStack(Thread*, void*, bool); 738 739 DISALLOW_COPY_AND_ASSIGN(Instrumentation); 740 }; 741 std::ostream& operator<<(std::ostream& os, Instrumentation::InstrumentationEvent rhs); 742 std::ostream& operator<<(std::ostream& os, Instrumentation::InstrumentationLevel rhs); 743 744 // An element in the instrumentation side stack maintained in art::Thread. 745 struct InstrumentationStackFrame { InstrumentationStackFrameInstrumentationStackFrame746 InstrumentationStackFrame(mirror::Object* this_object, 747 ArtMethod* method, 748 uintptr_t return_pc, 749 bool interpreter_entry, 750 uint64_t force_deopt_id) 751 : this_object_(this_object), 752 method_(method), 753 return_pc_(return_pc), 754 interpreter_entry_(interpreter_entry), 755 force_deopt_id_(force_deopt_id) { 756 } 757 758 std::string Dump() const REQUIRES_SHARED(Locks::mutator_lock_); 759 760 mirror::Object* this_object_; 761 ArtMethod* method_; 762 uintptr_t return_pc_; 763 bool interpreter_entry_; 764 uint64_t force_deopt_id_; 765 }; 766 767 } // namespace instrumentation 768 } // namespace art 769 770 #endif // ART_RUNTIME_INSTRUMENTATION_H_ 771