| // Copyright 2012 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef BASE_SEQUENCE_CHECKER_IMPL_H_ |
| #define BASE_SEQUENCE_CHECKER_IMPL_H_ |
| |
| #include<cstdint> |
| #include<memory> |
| #include<vector> |
| |
| #include"base/base_export.h" |
| #include"base/sequence_token.h" |
| #include"base/synchronization/lock.h" |
| #include"base/thread_annotations.h" |
| #include"base/threading/platform_thread_ref.h" |
| |
| namespacebase{ |
| namespace debug{ |
| classStackTrace; |
| } |
| |
| // Real implementation of SequenceChecker. |
| // |
| // In most cases, SEQUENCE_CHECKER should be used instead of this, get the right |
| // implementation for the build configuration. It's possible to temporarily use |
| // this directly to get sequence checking in production builds, which can be |
| // handy to debug issues only seen in the field. However, when used in a |
| // non-DCHECK build, SequenceCheckerImpl::CalledOnValidSequence() will not |
| // consider locks as a valid way to guarantee mutual exclusion (returns false if |
| // not invoked from the bound sequence, even if all calls are made under the |
| // same lock). |
| |
| // Marked with "context" capability to support thread_annotations.h. |
| class THREAD_ANNOTATION_ATTRIBUTE__(capability("context")) |
| BASE_EXPORTSequenceCheckerImpl{ |
| public: |
| staticvoidEnableStackLogging(); |
| |
| SequenceCheckerImpl(); |
| |
| // Allow move construct/assign. This must be called on |other|'s associated |
| // sequence and assignment can only be made into a SequenceCheckerImpl which |
| // is detached or already associated with the current sequence. This isn't |
| // thread-safe (|this| and |other| shouldn't be in use while this move is |
| // performed). If the assignment was legal, the resulting SequenceCheckerImpl |
| // will be bound to the current sequence and |other| will be detached. |
| SequenceCheckerImpl(SequenceCheckerImpl&& other); |
| SequenceCheckerImpl&operator=(SequenceCheckerImpl&& other); |
| SequenceCheckerImpl(constSequenceCheckerImpl&)=delete; |
| SequenceCheckerImpl&operator=(constSequenceCheckerImpl&)=delete; |
| ~SequenceCheckerImpl(); |
| |
| // Returns true if called in sequence with previous calls to this method and |
| // the constructor. |
| // On returning false, if logging is enabled with EnableStackLogging() and |
| // `out_bound_at` is not null, this method allocates a StackTrace and returns |
| // it in the out-parameter, storing inside it the stack from where the failing |
| // SequenceChecker was bound to its sequence. Otherwise, out_bound_at is left |
| // untouched. |
| [[nodiscard]]boolCalledOnValidSequence( |
| std::unique_ptr<debug::StackTrace>* out_bound_at=nullptr)const; |
| |
| // Unbinds the checker from the currently associated sequence. The checker |
| // will be re-bound on the next call to CalledOnValidSequence(). |
| voidDetachFromSequence(); |
| |
| private: |
| voidEnsureAssigned()const EXCLUSIVE_LOCKS_REQUIRED(lock_); |
| |
| // Members are mutable so that `CalledOnValidSequence()` can set them. |
| |
| mutableLock lock_; |
| |
| // Stack from which this was bound (set if `EnableStackLogging()` was called). |
| mutable std::unique_ptr<debug::StackTrace> bound_at_ GUARDED_BY(lock_); |
| |
| // Sequence to which this is bound. |
| mutableinternal::SequenceToken sequence_token_ GUARDED_BY(lock_); |
| |
| #if DCHECK_IS_ON() |
| // Locks to which this is bound. |
| mutable std::vector<uintptr_t> locks_ GUARDED_BY(lock_); |
| #endif// DCHECK_IS_ON() |
| |
| // Thread to which this is bound. Only used to evaluate |
| // `CalledOnValidSequence()` after TLS destruction. |
| mutablePlatformThreadRef thread_ref_ GUARDED_BY(lock_); |
| }; |
| |
| }// namespace base |
| |
| #endif// BASE_SEQUENCE_CHECKER_IMPL_H_ |
