| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef ART_RUNTIME_THREAD_LIST_H_ |
| #define ART_RUNTIME_THREAD_LIST_H_ |
| |
| #include "barrier.h" |
| #include "base/histogram.h" |
| #include "base/mutex.h" |
| #include "base/value_object.h" |
| #include "jni.h" |
| #include "reflective_handle_scope.h" |
| #include "suspend_reason.h" |
| |
| #include <bitset> |
| #include <list> |
| #include <vector> |
| |
| namespace art { |
| namespace gc { |
| namespace collector { |
| class GarbageCollector; |
| } // namespace collector |
| class GcPauseListener; |
| } // namespace gc |
| class Closure; |
| class IsMarkedVisitor; |
| class RootVisitor; |
| class Thread; |
| class TimingLogger; |
| enum VisitRootFlags : uint8_t; |
| |
| class ThreadList { |
| public: |
| static constexpr uint32_t kMaxThreadId = 0xFFFF; |
| static constexpr uint32_t kInvalidThreadId = 0; |
| static constexpr uint32_t kMainThreadId = 1; |
| static constexpr uint64_t kDefaultThreadSuspendTimeout = |
| kIsDebugBuild ? 50'000'000'000ull : 10'000'000'000ull; |
| |
| explicit ThreadList(uint64_t thread_suspend_timeout_ns); |
| ~ThreadList(); |
| |
| void ShutDown(); |
| |
| void DumpForSigQuit(std::ostream& os) |
| REQUIRES(!Locks::thread_list_lock_, !Locks::mutator_lock_); |
| // For thread suspend timeout dumps. |
| void Dump(std::ostream& os, bool dump_native_stack = true) |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| pid_t GetLockOwner(); // For SignalCatcher. |
| |
| // Thread suspension support. |
| void ResumeAll() |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_) |
| UNLOCK_FUNCTION(Locks::mutator_lock_); |
| bool Resume(Thread* thread, SuspendReason reason = SuspendReason::kInternal) |
| REQUIRES(!Locks::thread_suspend_count_lock_) WARN_UNUSED; |
| |
| // Suspends all threads and gets exclusive access to the mutator lock. |
| // If long_suspend is true, then other threads who try to suspend will never timeout. |
| // long_suspend is currenly used for hprof since large heaps take a long time. |
| void SuspendAll(const char* cause, bool long_suspend = false) |
| EXCLUSIVE_LOCK_FUNCTION(Locks::mutator_lock_) |
| REQUIRES(!Locks::thread_list_lock_, |
| !Locks::thread_suspend_count_lock_, |
| !Locks::mutator_lock_); |
| |
| // Suspend a thread using a peer, typically used by the debugger. Returns the thread on success, |
| // else null. The peer is used to identify the thread to avoid races with the thread terminating. |
| // If the thread should be suspended then value of request_suspension should be true otherwise |
| // the routine will wait for a previous suspend request. If the suspension times out then *timeout |
| // is set to true. |
| Thread* SuspendThreadByPeer(jobject peer, |
| bool request_suspension, |
| SuspendReason reason, |
| bool* timed_out) |
| REQUIRES(!Locks::mutator_lock_, |
| !Locks::thread_list_lock_, |
| !Locks::thread_suspend_count_lock_); |
| |
| // Suspend a thread using its thread id, typically used by lock/monitor inflation. Returns the |
| // thread on success else null. The thread id is used to identify the thread to avoid races with |
| // the thread terminating. Note that as thread ids are recycled this may not suspend the expected |
| // thread, that may be terminating. If the suspension times out then *timeout is set to true. |
| Thread* SuspendThreadByThreadId(uint32_t thread_id, SuspendReason reason, bool* timed_out) |
| REQUIRES(!Locks::mutator_lock_, |
| !Locks::thread_list_lock_, |
| !Locks::thread_suspend_count_lock_); |
| |
| // Find an existing thread (or self) by its thread id (not tid). |
| Thread* FindThreadByThreadId(uint32_t thread_id) REQUIRES(Locks::thread_list_lock_); |
| |
| // Does the thread list still contain the given thread, or one at the same address? |
| // Used by Monitor to provide (mostly accurate) debugging information. |
| bool Contains(Thread* thread) REQUIRES(Locks::thread_list_lock_); |
| |
| // Run a checkpoint on threads, running threads are not suspended but run the checkpoint inside |
| // of the suspend check. Returns how many checkpoints that are expected to run, including for |
| // already suspended threads for b/24191051. Run the callback, if non-null, inside the |
| // thread_list_lock critical section after determining the runnable/suspended states of the |
| // threads. |
| size_t RunCheckpoint(Closure* checkpoint_function, Closure* callback = nullptr) |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| |
| // Run an empty checkpoint on threads. Wait until threads pass the next suspend point or are |
| // suspended. This is used to ensure that the threads finish or aren't in the middle of an |
| // in-flight mutator heap access (eg. a read barrier.) Runnable threads will respond by |
| // decrementing the empty checkpoint barrier count. This works even when the weak ref access is |
| // disabled. Only one concurrent use is currently supported. |
| void RunEmptyCheckpoint() |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| |
| // Flip thread roots from from-space refs to to-space refs. Used by |
| // the concurrent copying collector. |
| size_t FlipThreadRoots(Closure* thread_flip_visitor, |
| Closure* flip_callback, |
| gc::collector::GarbageCollector* collector, |
| gc::GcPauseListener* pause_listener) |
| REQUIRES(!Locks::mutator_lock_, |
| !Locks::thread_list_lock_, |
| !Locks::thread_suspend_count_lock_); |
| |
| // Suspends all threads |
| void SuspendAllForDebugger() |
| REQUIRES(!Locks::mutator_lock_, |
| !Locks::thread_list_lock_, |
| !Locks::thread_suspend_count_lock_); |
| |
| void SuspendSelfForDebugger() |
| REQUIRES(!Locks::thread_suspend_count_lock_); |
| |
| // Resume all threads |
| void ResumeAllForDebugger() |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| |
| void UndoDebuggerSuspensions() |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| |
| // Iterates over all the threads. |
| void ForEach(void (*callback)(Thread*, void*), void* context) |
| REQUIRES(Locks::thread_list_lock_); |
| |
| template<typename CallBack> |
| void ForEach(CallBack cb) REQUIRES(Locks::thread_list_lock_) { |
| ForEach([](Thread* t, void* ctx) REQUIRES(Locks::thread_list_lock_) { |
| (*reinterpret_cast<CallBack*>(ctx))(t); |
| }, &cb); |
| } |
| |
| // Add/remove current thread from list. |
| void Register(Thread* self) |
| REQUIRES(Locks::runtime_shutdown_lock_) |
| REQUIRES(!Locks::mutator_lock_, |
| !Locks::thread_list_lock_, |
| !Locks::thread_suspend_count_lock_); |
| void Unregister(Thread* self) |
| REQUIRES(!Locks::mutator_lock_, |
| !Locks::thread_list_lock_, |
| !Locks::thread_suspend_count_lock_); |
| |
| void VisitRoots(RootVisitor* visitor, VisitRootFlags flags) const |
| REQUIRES_SHARED(Locks::mutator_lock_); |
| |
| void VisitRootsForSuspendedThreads(RootVisitor* visitor) |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_) |
| REQUIRES_SHARED(Locks::mutator_lock_); |
| |
| void VisitReflectiveTargets(ReflectiveValueVisitor* visitor) const REQUIRES(Locks::mutator_lock_); |
| |
| // Return a copy of the thread list. |
| std::list<Thread*> GetList() REQUIRES(Locks::thread_list_lock_) { |
| return list_; |
| } |
| |
| void DumpNativeStacks(std::ostream& os) |
| REQUIRES(!Locks::thread_list_lock_); |
| |
| Barrier* EmptyCheckpointBarrier() { |
| return empty_checkpoint_barrier_.get(); |
| } |
| |
| void SweepInterpreterCaches(IsMarkedVisitor* visitor) const |
| REQUIRES(!Locks::thread_list_lock_) |
| REQUIRES_SHARED(Locks::mutator_lock_); |
| |
| private: |
| uint32_t AllocThreadId(Thread* self); |
| void ReleaseThreadId(Thread* self, uint32_t id) REQUIRES(!Locks::allocated_thread_ids_lock_); |
| |
| bool Contains(pid_t tid) REQUIRES(Locks::thread_list_lock_); |
| size_t RunCheckpoint(Closure* checkpoint_function, bool includeSuspended) |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| |
| void DumpUnattachedThreads(std::ostream& os, bool dump_native_stack) |
| REQUIRES(!Locks::thread_list_lock_); |
| |
| void SuspendAllDaemonThreadsForShutdown() |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| void WaitForOtherNonDaemonThreadsToExit() |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| |
| void SuspendAllInternal(Thread* self, |
| Thread* ignore1, |
| Thread* ignore2 = nullptr, |
| SuspendReason reason = SuspendReason::kInternal) |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| |
| void AssertThreadsAreSuspended(Thread* self, Thread* ignore1, Thread* ignore2 = nullptr) |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_); |
| |
| std::bitset<kMaxThreadId> allocated_ids_ GUARDED_BY(Locks::allocated_thread_ids_lock_); |
| |
| // The actual list of all threads. |
| std::list<Thread*> list_ GUARDED_BY(Locks::thread_list_lock_); |
| |
| // Ongoing suspend all requests, used to ensure threads added to list_ respect SuspendAll. |
| int suspend_all_count_ GUARDED_BY(Locks::thread_suspend_count_lock_); |
| int debug_suspend_all_count_ GUARDED_BY(Locks::thread_suspend_count_lock_); |
| |
| // Number of threads unregistering, ~ThreadList blocks until this hits 0. |
| int unregistering_count_ GUARDED_BY(Locks::thread_list_lock_); |
| |
| // Thread suspend time histogram. Only modified when all the threads are suspended, so guarding |
| // by mutator lock ensures no thread can read when another thread is modifying it. |
| Histogram<uint64_t> suspend_all_historam_ GUARDED_BY(Locks::mutator_lock_); |
| |
| // Whether or not the current thread suspension is long. |
| bool long_suspend_; |
| |
| // Whether the shutdown function has been called. This is checked in the destructor. It is an |
| // error to destroy a ThreadList instance without first calling ShutDown(). |
| bool shut_down_; |
| |
| // Thread suspension timeout in nanoseconds. |
| const uint64_t thread_suspend_timeout_ns_; |
| |
| std::unique_ptr<Barrier> empty_checkpoint_barrier_; |
| |
| friend class Thread; |
| |
| DISALLOW_COPY_AND_ASSIGN(ThreadList); |
| }; |
| |
| // Helper for suspending all threads and getting exclusive access to the mutator lock. |
| class ScopedSuspendAll : public ValueObject { |
| public: |
| explicit ScopedSuspendAll(const char* cause, bool long_suspend = false) |
| EXCLUSIVE_LOCK_FUNCTION(Locks::mutator_lock_) |
| REQUIRES(!Locks::thread_list_lock_, |
| !Locks::thread_suspend_count_lock_, |
| !Locks::mutator_lock_); |
| // No REQUIRES(mutator_lock_) since the unlock function already asserts this. |
| ~ScopedSuspendAll() |
| REQUIRES(!Locks::thread_list_lock_, !Locks::thread_suspend_count_lock_) |
| UNLOCK_FUNCTION(Locks::mutator_lock_); |
| }; |
| |
| } // namespace art |
| |
| #endif // ART_RUNTIME_THREAD_LIST_H_ |