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Diffstat (limited to 'runtime/base/locks.cc')
| -rw-r--r-- | runtime/base/locks.cc | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/runtime/base/locks.cc b/runtime/base/locks.cc new file mode 100644 index 0000000000..cfc9f1d469 --- /dev/null +++ b/runtime/base/locks.cc @@ -0,0 +1,384 @@ +/* + * 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. + */ + +#include "locks.h" + +#include <errno.h> +#include <sys/time.h> + +#include "android-base/logging.h" + +#include "base/atomic.h" +#include "base/logging.h" +#include "base/systrace.h" +#include "base/time_utils.h" +#include "base/value_object.h" +#include "mutex-inl.h" +#include "scoped_thread_state_change-inl.h" +#include "thread-inl.h" + +namespace art { + +static Atomic<Locks::ClientCallback*> safe_to_call_abort_callback(nullptr); + +Mutex* Locks::abort_lock_ = nullptr; +Mutex* Locks::alloc_tracker_lock_ = nullptr; +Mutex* Locks::allocated_monitor_ids_lock_ = nullptr; +Mutex* Locks::allocated_thread_ids_lock_ = nullptr; +ReaderWriterMutex* Locks::breakpoint_lock_ = nullptr; +ReaderWriterMutex* Locks::classlinker_classes_lock_ = nullptr; +Mutex* Locks::custom_tls_lock_ = nullptr; +Mutex* Locks::deoptimization_lock_ = nullptr; +ReaderWriterMutex* Locks::heap_bitmap_lock_ = nullptr; +Mutex* Locks::instrument_entrypoints_lock_ = nullptr; +Mutex* Locks::intern_table_lock_ = nullptr; +Mutex* Locks::jni_function_table_lock_ = nullptr; +Mutex* Locks::jni_libraries_lock_ = nullptr; +Mutex* Locks::logging_lock_ = nullptr; +Mutex* Locks::modify_ldt_lock_ = nullptr; +MutatorMutex* Locks::mutator_lock_ = nullptr; +Mutex* Locks::profiler_lock_ = nullptr; +ReaderWriterMutex* Locks::verifier_deps_lock_ = nullptr; +ReaderWriterMutex* Locks::oat_file_manager_lock_ = nullptr; +Mutex* Locks::host_dlopen_handles_lock_ = nullptr; +Mutex* Locks::reference_processor_lock_ = nullptr; +Mutex* Locks::reference_queue_cleared_references_lock_ = nullptr; +Mutex* Locks::reference_queue_finalizer_references_lock_ = nullptr; +Mutex* Locks::reference_queue_phantom_references_lock_ = nullptr; +Mutex* Locks::reference_queue_soft_references_lock_ = nullptr; +Mutex* Locks::reference_queue_weak_references_lock_ = nullptr; +Mutex* Locks::runtime_shutdown_lock_ = nullptr; +Mutex* Locks::cha_lock_ = nullptr; +Mutex* Locks::subtype_check_lock_ = nullptr; +Mutex* Locks::thread_list_lock_ = nullptr; +ConditionVariable* Locks::thread_exit_cond_ = nullptr; +Mutex* Locks::thread_suspend_count_lock_ = nullptr; +Mutex* Locks::trace_lock_ = nullptr; +Mutex* Locks::unexpected_signal_lock_ = nullptr; +Mutex* Locks::user_code_suspension_lock_ = nullptr; +Uninterruptible Roles::uninterruptible_; +ReaderWriterMutex* Locks::jni_globals_lock_ = nullptr; +Mutex* Locks::jni_weak_globals_lock_ = nullptr; +ReaderWriterMutex* Locks::dex_lock_ = nullptr; +Mutex* Locks::native_debug_interface_lock_ = nullptr; +std::vector<BaseMutex*> Locks::expected_mutexes_on_weak_ref_access_; +Atomic<const BaseMutex*> Locks::expected_mutexes_on_weak_ref_access_guard_; + +// Wait for an amount of time that roughly increases in the argument i. +// Spin for small arguments and yield/sleep for longer ones. +static void BackOff(uint32_t i) { + static constexpr uint32_t kSpinMax = 10; + static constexpr uint32_t kYieldMax = 20; + if (i <= kSpinMax) { + // TODO: Esp. in very latency-sensitive cases, consider replacing this with an explicit + // test-and-test-and-set loop in the caller. Possibly skip entirely on a uniprocessor. + volatile uint32_t x = 0; + const uint32_t spin_count = 10 * i; + for (uint32_t spin = 0; spin < spin_count; ++spin) { + ++x; // Volatile; hence should not be optimized away. + } + // TODO: Consider adding x86 PAUSE and/or ARM YIELD here. + } else if (i <= kYieldMax) { + sched_yield(); + } else { + NanoSleep(1000ull * (i - kYieldMax)); + } +} + +class Locks::ScopedExpectedMutexesOnWeakRefAccessLock final { + public: + explicit ScopedExpectedMutexesOnWeakRefAccessLock(const BaseMutex* mutex) : mutex_(mutex) { + for (uint32_t i = 0; + !Locks::expected_mutexes_on_weak_ref_access_guard_.CompareAndSetWeakAcquire(nullptr, + mutex); + ++i) { + BackOff(i); + } + } + + ~ScopedExpectedMutexesOnWeakRefAccessLock() { + DCHECK_EQ(Locks::expected_mutexes_on_weak_ref_access_guard_.load(std::memory_order_relaxed), + mutex_); + Locks::expected_mutexes_on_weak_ref_access_guard_.store(nullptr, std::memory_order_release); + } + + private: + const BaseMutex* const mutex_; +}; + +void Locks::Init() { + if (logging_lock_ != nullptr) { + // Already initialized. + if (kRuntimeISA == InstructionSet::kX86 || kRuntimeISA == InstructionSet::kX86_64) { + DCHECK(modify_ldt_lock_ != nullptr); + } else { + DCHECK(modify_ldt_lock_ == nullptr); + } + DCHECK(abort_lock_ != nullptr); + DCHECK(alloc_tracker_lock_ != nullptr); + DCHECK(allocated_monitor_ids_lock_ != nullptr); + DCHECK(allocated_thread_ids_lock_ != nullptr); + DCHECK(breakpoint_lock_ != nullptr); + DCHECK(classlinker_classes_lock_ != nullptr); + DCHECK(custom_tls_lock_ != nullptr); + DCHECK(deoptimization_lock_ != nullptr); + DCHECK(heap_bitmap_lock_ != nullptr); + DCHECK(oat_file_manager_lock_ != nullptr); + DCHECK(verifier_deps_lock_ != nullptr); + DCHECK(host_dlopen_handles_lock_ != nullptr); + DCHECK(intern_table_lock_ != nullptr); + DCHECK(jni_function_table_lock_ != nullptr); + DCHECK(jni_libraries_lock_ != nullptr); + DCHECK(logging_lock_ != nullptr); + DCHECK(mutator_lock_ != nullptr); + DCHECK(profiler_lock_ != nullptr); + DCHECK(cha_lock_ != nullptr); + DCHECK(subtype_check_lock_ != nullptr); + DCHECK(thread_list_lock_ != nullptr); + DCHECK(thread_suspend_count_lock_ != nullptr); + DCHECK(trace_lock_ != nullptr); + DCHECK(unexpected_signal_lock_ != nullptr); + DCHECK(user_code_suspension_lock_ != nullptr); + DCHECK(dex_lock_ != nullptr); + DCHECK(native_debug_interface_lock_ != nullptr); + } else { + // Create global locks in level order from highest lock level to lowest. + LockLevel current_lock_level = kInstrumentEntrypointsLock; + DCHECK(instrument_entrypoints_lock_ == nullptr); + instrument_entrypoints_lock_ = new Mutex("instrument entrypoint lock", current_lock_level); + + #define UPDATE_CURRENT_LOCK_LEVEL(new_level) \ + if ((new_level) >= current_lock_level) { \ + /* Do not use CHECKs or FATAL here, abort_lock_ is not setup yet. */ \ + fprintf(stderr, "New local level %d is not less than current level %d\n", \ + new_level, current_lock_level); \ + exit(1); \ + } \ + current_lock_level = new_level; + + UPDATE_CURRENT_LOCK_LEVEL(kUserCodeSuspensionLock); + DCHECK(user_code_suspension_lock_ == nullptr); + user_code_suspension_lock_ = new Mutex("user code suspension lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kMutatorLock); + DCHECK(mutator_lock_ == nullptr); + mutator_lock_ = new MutatorMutex("mutator lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kHeapBitmapLock); + DCHECK(heap_bitmap_lock_ == nullptr); + heap_bitmap_lock_ = new ReaderWriterMutex("heap bitmap lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kTraceLock); + DCHECK(trace_lock_ == nullptr); + trace_lock_ = new Mutex("trace lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kRuntimeShutdownLock); + DCHECK(runtime_shutdown_lock_ == nullptr); + runtime_shutdown_lock_ = new Mutex("runtime shutdown lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kProfilerLock); + DCHECK(profiler_lock_ == nullptr); + profiler_lock_ = new Mutex("profiler lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kDeoptimizationLock); + DCHECK(deoptimization_lock_ == nullptr); + deoptimization_lock_ = new Mutex("Deoptimization lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kAllocTrackerLock); + DCHECK(alloc_tracker_lock_ == nullptr); + alloc_tracker_lock_ = new Mutex("AllocTracker lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kThreadListLock); + DCHECK(thread_list_lock_ == nullptr); + thread_list_lock_ = new Mutex("thread list lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kJniLoadLibraryLock); + DCHECK(jni_libraries_lock_ == nullptr); + jni_libraries_lock_ = new Mutex("JNI shared libraries map lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kBreakpointLock); + DCHECK(breakpoint_lock_ == nullptr); + breakpoint_lock_ = new ReaderWriterMutex("breakpoint lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kSubtypeCheckLock); + DCHECK(subtype_check_lock_ == nullptr); + subtype_check_lock_ = new Mutex("SubtypeCheck lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kClassLinkerClassesLock); + DCHECK(classlinker_classes_lock_ == nullptr); + classlinker_classes_lock_ = new ReaderWriterMutex("ClassLinker classes lock", + current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kMonitorPoolLock); + DCHECK(allocated_monitor_ids_lock_ == nullptr); + allocated_monitor_ids_lock_ = new Mutex("allocated monitor ids lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kAllocatedThreadIdsLock); + DCHECK(allocated_thread_ids_lock_ == nullptr); + allocated_thread_ids_lock_ = new Mutex("allocated thread ids lock", current_lock_level); + + if (kRuntimeISA == InstructionSet::kX86 || kRuntimeISA == InstructionSet::kX86_64) { + UPDATE_CURRENT_LOCK_LEVEL(kModifyLdtLock); + DCHECK(modify_ldt_lock_ == nullptr); + modify_ldt_lock_ = new Mutex("modify_ldt lock", current_lock_level); + } + + UPDATE_CURRENT_LOCK_LEVEL(kDexLock); + DCHECK(dex_lock_ == nullptr); + dex_lock_ = new ReaderWriterMutex("ClassLinker dex lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kOatFileManagerLock); + DCHECK(oat_file_manager_lock_ == nullptr); + oat_file_manager_lock_ = new ReaderWriterMutex("OatFile manager lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kVerifierDepsLock); + DCHECK(verifier_deps_lock_ == nullptr); + verifier_deps_lock_ = new ReaderWriterMutex("verifier deps lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kHostDlOpenHandlesLock); + DCHECK(host_dlopen_handles_lock_ == nullptr); + host_dlopen_handles_lock_ = new Mutex("host dlopen handles lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kInternTableLock); + DCHECK(intern_table_lock_ == nullptr); + intern_table_lock_ = new Mutex("InternTable lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kReferenceProcessorLock); + DCHECK(reference_processor_lock_ == nullptr); + reference_processor_lock_ = new Mutex("ReferenceProcessor lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueueClearedReferencesLock); + DCHECK(reference_queue_cleared_references_lock_ == nullptr); + reference_queue_cleared_references_lock_ = new Mutex("ReferenceQueue cleared references lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueueWeakReferencesLock); + DCHECK(reference_queue_weak_references_lock_ == nullptr); + reference_queue_weak_references_lock_ = new Mutex("ReferenceQueue cleared references lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueueFinalizerReferencesLock); + DCHECK(reference_queue_finalizer_references_lock_ == nullptr); + reference_queue_finalizer_references_lock_ = new Mutex("ReferenceQueue finalizer references lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueuePhantomReferencesLock); + DCHECK(reference_queue_phantom_references_lock_ == nullptr); + reference_queue_phantom_references_lock_ = new Mutex("ReferenceQueue phantom references lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueueSoftReferencesLock); + DCHECK(reference_queue_soft_references_lock_ == nullptr); + reference_queue_soft_references_lock_ = new Mutex("ReferenceQueue soft references lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kJniGlobalsLock); + DCHECK(jni_globals_lock_ == nullptr); + jni_globals_lock_ = + new ReaderWriterMutex("JNI global reference table lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kJniWeakGlobalsLock); + DCHECK(jni_weak_globals_lock_ == nullptr); + jni_weak_globals_lock_ = new Mutex("JNI weak global reference table lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kJniFunctionTableLock); + DCHECK(jni_function_table_lock_ == nullptr); + jni_function_table_lock_ = new Mutex("JNI function table lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kCustomTlsLock); + DCHECK(custom_tls_lock_ == nullptr); + custom_tls_lock_ = new Mutex("Thread::custom_tls_ lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kCHALock); + DCHECK(cha_lock_ == nullptr); + cha_lock_ = new Mutex("CHA lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kNativeDebugInterfaceLock); + DCHECK(native_debug_interface_lock_ == nullptr); + native_debug_interface_lock_ = new Mutex("Native debug interface lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kAbortLock); + DCHECK(abort_lock_ == nullptr); + abort_lock_ = new Mutex("abort lock", current_lock_level, true); + + UPDATE_CURRENT_LOCK_LEVEL(kThreadSuspendCountLock); + DCHECK(thread_suspend_count_lock_ == nullptr); + thread_suspend_count_lock_ = new Mutex("thread suspend count lock", current_lock_level); + + UPDATE_CURRENT_LOCK_LEVEL(kUnexpectedSignalLock); + DCHECK(unexpected_signal_lock_ == nullptr); + unexpected_signal_lock_ = new Mutex("unexpected signal lock", current_lock_level, true); + + UPDATE_CURRENT_LOCK_LEVEL(kLoggingLock); + DCHECK(logging_lock_ == nullptr); + logging_lock_ = new Mutex("logging lock", current_lock_level, true); + + #undef UPDATE_CURRENT_LOCK_LEVEL + + // List of mutexes that we may hold when accessing a weak ref. + AddToExpectedMutexesOnWeakRefAccess(dex_lock_, /*need_lock=*/ false); + AddToExpectedMutexesOnWeakRefAccess(classlinker_classes_lock_, /*need_lock=*/ false); + AddToExpectedMutexesOnWeakRefAccess(jni_libraries_lock_, /*need_lock=*/ false); + + InitConditions(); + } +} + +void Locks::InitConditions() { + thread_exit_cond_ = new ConditionVariable("thread exit condition variable", *thread_list_lock_); +} + +void Locks::SetClientCallback(ClientCallback* safe_to_call_abort_cb) { + safe_to_call_abort_callback.store(safe_to_call_abort_cb, std::memory_order_release); +} + +// Helper to allow checking shutdown while ignoring locking requirements. +bool Locks::IsSafeToCallAbortRacy() { + Locks::ClientCallback* safe_to_call_abort_cb = + safe_to_call_abort_callback.load(std::memory_order_acquire); + return safe_to_call_abort_cb != nullptr && safe_to_call_abort_cb(); +} + +void Locks::AddToExpectedMutexesOnWeakRefAccess(BaseMutex* mutex, bool need_lock) { + if (need_lock) { + ScopedExpectedMutexesOnWeakRefAccessLock mu(mutex); + mutex->SetShouldRespondToEmptyCheckpointRequest(true); + expected_mutexes_on_weak_ref_access_.push_back(mutex); + } else { + mutex->SetShouldRespondToEmptyCheckpointRequest(true); + expected_mutexes_on_weak_ref_access_.push_back(mutex); + } +} + +void Locks::RemoveFromExpectedMutexesOnWeakRefAccess(BaseMutex* mutex, bool need_lock) { + if (need_lock) { + ScopedExpectedMutexesOnWeakRefAccessLock mu(mutex); + mutex->SetShouldRespondToEmptyCheckpointRequest(false); + std::vector<BaseMutex*>& list = expected_mutexes_on_weak_ref_access_; + auto it = std::find(list.begin(), list.end(), mutex); + DCHECK(it != list.end()); + list.erase(it); + } else { + mutex->SetShouldRespondToEmptyCheckpointRequest(false); + std::vector<BaseMutex*>& list = expected_mutexes_on_weak_ref_access_; + auto it = std::find(list.begin(), list.end(), mutex); + DCHECK(it != list.end()); + list.erase(it); + } +} + +bool Locks::IsExpectedOnWeakRefAccess(BaseMutex* mutex) { + ScopedExpectedMutexesOnWeakRefAccessLock mu(mutex); + std::vector<BaseMutex*>& list = expected_mutexes_on_weak_ref_access_; + return std::find(list.begin(), list.end(), mutex) != list.end(); +} + +} // namespace art |