1 // Copyright (c) 2012 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 #include "base/thread_task_runner_handle.h" 6 7 #include "base/lazy_instance.h" 8 #include "base/single_thread_task_runner.h" 9 #include "base/threading/thread_local.h" 10 11 namespace base { 12 13 namespace { 14 15 base::LazyInstance<base::ThreadLocalPointer<ThreadTaskRunnerHandle> > 16 lazy_tls_ptr = LAZY_INSTANCE_INITIALIZER; 17 18 } // namespace 19 20 // static Get()21scoped_refptr<SingleThreadTaskRunner> ThreadTaskRunnerHandle::Get() { 22 ThreadTaskRunnerHandle* current = lazy_tls_ptr.Pointer()->Get(); 23 DCHECK(current); 24 return current->task_runner_; 25 } 26 27 // static IsSet()28bool ThreadTaskRunnerHandle::IsSet() { 29 return lazy_tls_ptr.Pointer()->Get() != NULL; 30 } 31 ThreadTaskRunnerHandle(const scoped_refptr<SingleThreadTaskRunner> & task_runner)32ThreadTaskRunnerHandle::ThreadTaskRunnerHandle( 33 const scoped_refptr<SingleThreadTaskRunner>& task_runner) 34 : task_runner_(task_runner) { 35 DCHECK(task_runner_->BelongsToCurrentThread()); 36 DCHECK(!lazy_tls_ptr.Pointer()->Get()); 37 lazy_tls_ptr.Pointer()->Set(this); 38 } 39 ~ThreadTaskRunnerHandle()40ThreadTaskRunnerHandle::~ThreadTaskRunnerHandle() { 41 DCHECK(task_runner_->BelongsToCurrentThread()); 42 DCHECK_EQ(lazy_tls_ptr.Pointer()->Get(), this); 43 lazy_tls_ptr.Pointer()->Set(NULL); 44 } 45 46 } // namespace base 47