| /* |
| * 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_INL_H_ |
| #define ART_RUNTIME_THREAD_INL_H_ |
| |
| #include "thread.h" |
| |
| #ifdef ART_TARGET_ANDROID |
| #include <bionic_tls.h> // Access to our own TLS slot. |
| #endif |
| |
| #include <pthread.h> |
| |
| #include "base/casts.h" |
| #include "base/mutex-inl.h" |
| #include "gc/heap.h" |
| #include "jni_env_ext.h" |
| #include "thread_pool.h" |
| |
| namespace art { |
| |
| // Quickly access the current thread from a JNIEnv. |
| static inline Thread* ThreadForEnv(JNIEnv* env) { |
| JNIEnvExt* full_env(down_cast<JNIEnvExt*>(env)); |
| return full_env->self; |
| } |
| |
| inline Thread* Thread::Current() { |
| // We rely on Thread::Current returning null for a detached thread, so it's not obvious |
| // that we can replace this with a direct %fs access on x86. |
| if (!is_started_) { |
| return nullptr; |
| } else { |
| #ifdef ART_TARGET_ANDROID |
| void* thread = __get_tls()[TLS_SLOT_ART_THREAD_SELF]; |
| #else |
| void* thread = pthread_getspecific(Thread::pthread_key_self_); |
| #endif |
| return reinterpret_cast<Thread*>(thread); |
| } |
| } |
| |
| inline void Thread::AllowThreadSuspension() { |
| DCHECK_EQ(Thread::Current(), this); |
| if (UNLIKELY(TestAllFlags())) { |
| CheckSuspend(); |
| } |
| } |
| |
| inline void Thread::CheckSuspend() { |
| DCHECK_EQ(Thread::Current(), this); |
| for (;;) { |
| if (ReadFlag(kCheckpointRequest)) { |
| RunCheckpointFunction(); |
| } else if (ReadFlag(kSuspendRequest)) { |
| FullSuspendCheck(); |
| } else { |
| break; |
| } |
| } |
| } |
| |
| inline ThreadState Thread::SetState(ThreadState new_state) { |
| // Should only be used to change between suspended states. |
| // Cannot use this code to change into or from Runnable as changing to Runnable should |
| // fail if old_state_and_flags.suspend_request is true and changing from Runnable might |
| // miss passing an active suspend barrier. |
| DCHECK_NE(new_state, kRunnable); |
| if (kIsDebugBuild && this != Thread::Current()) { |
| std::string name; |
| GetThreadName(name); |
| LOG(FATAL) << "Thread \"" << name << "\"(" << this << " != Thread::Current()=" |
| << Thread::Current() << ") changing state to " << new_state; |
| } |
| union StateAndFlags old_state_and_flags; |
| old_state_and_flags.as_int = tls32_.state_and_flags.as_int; |
| CHECK_NE(old_state_and_flags.as_struct.state, kRunnable); |
| tls32_.state_and_flags.as_struct.state = new_state; |
| return static_cast<ThreadState>(old_state_and_flags.as_struct.state); |
| } |
| |
| inline bool Thread::IsThreadSuspensionAllowable() const { |
| if (tls32_.no_thread_suspension != 0) { |
| return false; |
| } |
| for (int i = kLockLevelCount - 1; i >= 0; --i) { |
| if (i != kMutatorLock && GetHeldMutex(static_cast<LockLevel>(i)) != nullptr) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| inline void Thread::AssertThreadSuspensionIsAllowable(bool check_locks) const { |
| if (kIsDebugBuild) { |
| if (gAborting == 0) { |
| CHECK_EQ(0u, tls32_.no_thread_suspension) << tlsPtr_.last_no_thread_suspension_cause; |
| } |
| if (check_locks) { |
| bool bad_mutexes_held = false; |
| for (int i = kLockLevelCount - 1; i >= 0; --i) { |
| // We expect no locks except the mutator_lock_ or thread list suspend thread lock. |
| if (i != kMutatorLock) { |
| BaseMutex* held_mutex = GetHeldMutex(static_cast<LockLevel>(i)); |
| if (held_mutex != nullptr) { |
| LOG(ERROR) << "holding \"" << held_mutex->GetName() |
| << "\" at point where thread suspension is expected"; |
| bad_mutexes_held = true; |
| } |
| } |
| } |
| if (gAborting == 0) { |
| CHECK(!bad_mutexes_held); |
| } |
| } |
| } |
| } |
| |
| inline void Thread::TransitionToSuspendedAndRunCheckpoints(ThreadState new_state) { |
| DCHECK_NE(new_state, kRunnable); |
| DCHECK_EQ(GetState(), kRunnable); |
| union StateAndFlags old_state_and_flags; |
| union StateAndFlags new_state_and_flags; |
| while (true) { |
| old_state_and_flags.as_int = tls32_.state_and_flags.as_int; |
| if (UNLIKELY((old_state_and_flags.as_struct.flags & kCheckpointRequest) != 0)) { |
| RunCheckpointFunction(); |
| continue; |
| } |
| // Change the state but keep the current flags (kCheckpointRequest is clear). |
| DCHECK_EQ((old_state_and_flags.as_struct.flags & kCheckpointRequest), 0); |
| new_state_and_flags.as_struct.flags = old_state_and_flags.as_struct.flags; |
| new_state_and_flags.as_struct.state = new_state; |
| |
| // CAS the value with a memory ordering. |
| bool done = |
| tls32_.state_and_flags.as_atomic_int.CompareExchangeWeakRelease(old_state_and_flags.as_int, |
| new_state_and_flags.as_int); |
| if (LIKELY(done)) { |
| break; |
| } |
| } |
| } |
| |
| inline void Thread::PassActiveSuspendBarriers() { |
| while (true) { |
| uint16_t current_flags = tls32_.state_and_flags.as_struct.flags; |
| if (LIKELY((current_flags & (kCheckpointRequest | kActiveSuspendBarrier)) == 0)) { |
| break; |
| } else if ((current_flags & kActiveSuspendBarrier) != 0) { |
| PassActiveSuspendBarriers(this); |
| } else { |
| // Impossible |
| LOG(FATAL) << "Fatal, thread transitioned into suspended without running the checkpoint"; |
| } |
| } |
| } |
| |
| inline void Thread::TransitionFromRunnableToSuspended(ThreadState new_state) { |
| AssertThreadSuspensionIsAllowable(); |
| DCHECK_EQ(this, Thread::Current()); |
| // Change to non-runnable state, thereby appearing suspended to the system. |
| TransitionToSuspendedAndRunCheckpoints(new_state); |
| // Mark the release of the share of the mutator_lock_. |
| Locks::mutator_lock_->TransitionFromRunnableToSuspended(this); |
| // Once suspended - check the active suspend barrier flag |
| PassActiveSuspendBarriers(); |
| } |
| |
| inline ThreadState Thread::TransitionFromSuspendedToRunnable() { |
| union StateAndFlags old_state_and_flags; |
| old_state_and_flags.as_int = tls32_.state_and_flags.as_int; |
| int16_t old_state = old_state_and_flags.as_struct.state; |
| DCHECK_NE(static_cast<ThreadState>(old_state), kRunnable); |
| do { |
| Locks::mutator_lock_->AssertNotHeld(this); // Otherwise we starve GC.. |
| old_state_and_flags.as_int = tls32_.state_and_flags.as_int; |
| DCHECK_EQ(old_state_and_flags.as_struct.state, old_state); |
| if (LIKELY(old_state_and_flags.as_struct.flags == 0)) { |
| // Optimize for the return from native code case - this is the fast path. |
| // Atomically change from suspended to runnable if no suspend request pending. |
| union StateAndFlags new_state_and_flags; |
| new_state_and_flags.as_int = old_state_and_flags.as_int; |
| new_state_and_flags.as_struct.state = kRunnable; |
| // CAS the value with a memory barrier. |
| if (LIKELY(tls32_.state_and_flags.as_atomic_int.CompareExchangeWeakAcquire( |
| old_state_and_flags.as_int, |
| new_state_and_flags.as_int))) { |
| // Mark the acquisition of a share of the mutator_lock_. |
| Locks::mutator_lock_->TransitionFromSuspendedToRunnable(this); |
| break; |
| } |
| } else if ((old_state_and_flags.as_struct.flags & kActiveSuspendBarrier) != 0) { |
| PassActiveSuspendBarriers(this); |
| } else if ((old_state_and_flags.as_struct.flags & kCheckpointRequest) != 0) { |
| // Impossible |
| LOG(FATAL) << "Transitioning to runnable with checkpoint flag, " |
| << " flags=" << old_state_and_flags.as_struct.flags |
| << " state=" << old_state_and_flags.as_struct.state; |
| } else if ((old_state_and_flags.as_struct.flags & kSuspendRequest) != 0) { |
| // Wait while our suspend count is non-zero. |
| |
| // We pass null to the MutexLock as we may be in a situation where the |
| // runtime is shutting down. Guarding ourselves from that situation |
| // requires to take the shutdown lock, which is undesirable here. |
| Thread* thread_to_pass = nullptr; |
| if (kIsDebugBuild && !IsDaemon()) { |
| // We know we can make our debug locking checks on non-daemon threads, |
| // so re-enable them on debug builds. |
| thread_to_pass = this; |
| } |
| MutexLock mu(thread_to_pass, *Locks::thread_suspend_count_lock_); |
| ScopedTransitioningToRunnable scoped_transitioning_to_runnable(this); |
| old_state_and_flags.as_int = tls32_.state_and_flags.as_int; |
| DCHECK_EQ(old_state_and_flags.as_struct.state, old_state); |
| while ((old_state_and_flags.as_struct.flags & kSuspendRequest) != 0) { |
| // Re-check when Thread::resume_cond_ is notified. |
| Thread::resume_cond_->Wait(thread_to_pass); |
| old_state_and_flags.as_int = tls32_.state_and_flags.as_int; |
| DCHECK_EQ(old_state_and_flags.as_struct.state, old_state); |
| } |
| DCHECK_EQ(GetSuspendCount(), 0); |
| } |
| } while (true); |
| // Run the flip function, if set. |
| Closure* flip_func = GetFlipFunction(); |
| if (flip_func != nullptr) { |
| flip_func->Run(this); |
| } |
| return static_cast<ThreadState>(old_state); |
| } |
| |
| inline void Thread::VerifyStack() { |
| if (kVerifyStack) { |
| if (Runtime::Current()->GetHeap()->IsObjectValidationEnabled()) { |
| VerifyStackImpl(); |
| } |
| } |
| } |
| |
| inline size_t Thread::TlabSize() const { |
| return tlsPtr_.thread_local_end - tlsPtr_.thread_local_pos; |
| } |
| |
| inline mirror::Object* Thread::AllocTlab(size_t bytes) { |
| DCHECK_GE(TlabSize(), bytes); |
| ++tlsPtr_.thread_local_objects; |
| mirror::Object* ret = reinterpret_cast<mirror::Object*>(tlsPtr_.thread_local_pos); |
| tlsPtr_.thread_local_pos += bytes; |
| return ret; |
| } |
| |
| inline bool Thread::PushOnThreadLocalAllocationStack(mirror::Object* obj) { |
| DCHECK_LE(tlsPtr_.thread_local_alloc_stack_top, tlsPtr_.thread_local_alloc_stack_end); |
| if (tlsPtr_.thread_local_alloc_stack_top < tlsPtr_.thread_local_alloc_stack_end) { |
| // There's room. |
| DCHECK_LE(reinterpret_cast<uint8_t*>(tlsPtr_.thread_local_alloc_stack_top) + |
| sizeof(StackReference<mirror::Object>), |
| reinterpret_cast<uint8_t*>(tlsPtr_.thread_local_alloc_stack_end)); |
| DCHECK(tlsPtr_.thread_local_alloc_stack_top->AsMirrorPtr() == nullptr); |
| tlsPtr_.thread_local_alloc_stack_top->Assign(obj); |
| ++tlsPtr_.thread_local_alloc_stack_top; |
| return true; |
| } |
| return false; |
| } |
| |
| inline void Thread::SetThreadLocalAllocationStack(StackReference<mirror::Object>* start, |
| StackReference<mirror::Object>* end) { |
| DCHECK(Thread::Current() == this) << "Should be called by self"; |
| DCHECK(start != nullptr); |
| DCHECK(end != nullptr); |
| DCHECK_ALIGNED(start, sizeof(StackReference<mirror::Object>)); |
| DCHECK_ALIGNED(end, sizeof(StackReference<mirror::Object>)); |
| DCHECK_LT(start, end); |
| tlsPtr_.thread_local_alloc_stack_end = end; |
| tlsPtr_.thread_local_alloc_stack_top = start; |
| } |
| |
| inline void Thread::RevokeThreadLocalAllocationStack() { |
| if (kIsDebugBuild) { |
| // Note: self is not necessarily equal to this thread since thread may be suspended. |
| Thread* self = Thread::Current(); |
| DCHECK(this == self || IsSuspended() || GetState() == kWaitingPerformingGc) |
| << GetState() << " thread " << this << " self " << self; |
| } |
| tlsPtr_.thread_local_alloc_stack_end = nullptr; |
| tlsPtr_.thread_local_alloc_stack_top = nullptr; |
| } |
| |
| } // namespace art |
| |
| #endif // ART_RUNTIME_THREAD_INL_H_ |