1 // Copyright 2016 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef BASE_THREADING_THREAD_TASK_RUNNER_HANDLE_H_ 6 #define BASE_THREADING_THREAD_TASK_RUNNER_HANDLE_H_ 7 8 #include "base/base_export.h" 9 #include "base/macros.h" 10 #include "base/memory/ref_counted.h" 11 #include "base/single_thread_task_runner.h" 12 13 namespace base { 14 15 // ThreadTaskRunnerHandle stores a reference to a thread's TaskRunner 16 // in thread-local storage. Callers can then retrieve the TaskRunner 17 // for the current thread by calling ThreadTaskRunnerHandle::Get(). 18 // At most one TaskRunner may be bound to each thread at a time. 19 // Prefer SequenceTaskRunnerHandle to this unless thread affinity is required. 20 class BASE_EXPORT ThreadTaskRunnerHandle { 21 public: 22 // Gets the SingleThreadTaskRunner for the current thread. 23 static scoped_refptr<SingleThreadTaskRunner> Get(); 24 25 // Returns true if the SingleThreadTaskRunner is already created for 26 // the current thread. 27 static bool IsSet(); 28 29 // Binds |task_runner| to the current thread. |task_runner| must belong 30 // to the current thread for this to succeed. 31 explicit ThreadTaskRunnerHandle( 32 scoped_refptr<SingleThreadTaskRunner> task_runner); 33 ~ThreadTaskRunnerHandle(); 34 35 private: 36 scoped_refptr<SingleThreadTaskRunner> task_runner_; 37 38 DISALLOW_COPY_AND_ASSIGN(ThreadTaskRunnerHandle); 39 }; 40 41 } // namespace base 42 43 #endif // BASE_THREADING_THREAD_TASK_RUNNER_HANDLE_H_ 44