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Diffstat (limited to 'security/sandbox/chromium/base/task_runner.h')
| -rw-r--r-- | security/sandbox/chromium/base/task_runner.h | 154 |
1 files changed, 0 insertions, 154 deletions
diff --git a/security/sandbox/chromium/base/task_runner.h b/security/sandbox/chromium/base/task_runner.h deleted file mode 100644 index 6dd82ccac..000000000 --- a/security/sandbox/chromium/base/task_runner.h +++ /dev/null @@ -1,154 +0,0 @@ -// Copyright (c) 2012 The Chromium Authors. All rights reserved. -// Use of this source code is governed by a BSD-style license that can be -// found in the LICENSE file. - -#ifndef BASE_TASK_RUNNER_H_ -#define BASE_TASK_RUNNER_H_ - -#include <stddef.h> - -#include "base/base_export.h" -#include "base/callback_forward.h" -#include "base/memory/ref_counted.h" -#include "base/time/time.h" - -namespace tracked_objects { -class Location; -} // namespace tracked_objects - -namespace base { - -struct TaskRunnerTraits; - -// A TaskRunner is an object that runs posted tasks (in the form of -// Closure objects). The TaskRunner interface provides a way of -// decoupling task posting from the mechanics of how each task will be -// run. TaskRunner provides very weak guarantees as to how posted -// tasks are run (or if they're run at all). In particular, it only -// guarantees: -// -// - Posting a task will not run it synchronously. That is, no -// Post*Task method will call task.Run() directly. -// -// - Increasing the delay can only delay when the task gets run. -// That is, increasing the delay may not affect when the task gets -// run, or it could make it run later than it normally would, but -// it won't make it run earlier than it normally would. -// -// TaskRunner does not guarantee the order in which posted tasks are -// run, whether tasks overlap, or whether they're run on a particular -// thread. Also it does not guarantee a memory model for shared data -// between tasks. (In other words, you should use your own -// synchronization/locking primitives if you need to share data -// between tasks.) -// -// Implementations of TaskRunner should be thread-safe in that all -// methods must be safe to call on any thread. Ownership semantics -// for TaskRunners are in general not clear, which is why the -// interface itself is RefCountedThreadSafe. -// -// Some theoretical implementations of TaskRunner: -// -// - A TaskRunner that uses a thread pool to run posted tasks. -// -// - A TaskRunner that, for each task, spawns a non-joinable thread -// to run that task and immediately quit. -// -// - A TaskRunner that stores the list of posted tasks and has a -// method Run() that runs each runnable task in random order. -class BASE_EXPORT TaskRunner - : public RefCountedThreadSafe<TaskRunner, TaskRunnerTraits> { - public: - // Posts the given task to be run. Returns true if the task may be - // run at some point in the future, and false if the task definitely - // will not be run. - // - // Equivalent to PostDelayedTask(from_here, task, 0). - bool PostTask(const tracked_objects::Location& from_here, - const Closure& task); - - // Like PostTask, but tries to run the posted task only after - // |delay_ms| has passed. - // - // It is valid for an implementation to ignore |delay_ms|; that is, - // to have PostDelayedTask behave the same as PostTask. - virtual bool PostDelayedTask(const tracked_objects::Location& from_here, - const Closure& task, - base::TimeDelta delay) = 0; - - // Returns true if the current thread is a thread on which a task - // may be run, and false if no task will be run on the current - // thread. - // - // It is valid for an implementation to always return true, or in - // general to use 'true' as a default value. - virtual bool RunsTasksOnCurrentThread() const = 0; - - // Posts |task| on the current TaskRunner. On completion, |reply| - // is posted to the thread that called PostTaskAndReply(). Both - // |task| and |reply| are guaranteed to be deleted on the thread - // from which PostTaskAndReply() is invoked. This allows objects - // that must be deleted on the originating thread to be bound into - // the |task| and |reply| Closures. In particular, it can be useful - // to use WeakPtr<> in the |reply| Closure so that the reply - // operation can be canceled. See the following pseudo-code: - // - // class DataBuffer : public RefCountedThreadSafe<DataBuffer> { - // public: - // // Called to add data into a buffer. - // void AddData(void* buf, size_t length); - // ... - // }; - // - // - // class DataLoader : public SupportsWeakPtr<DataLoader> { - // public: - // void GetData() { - // scoped_refptr<DataBuffer> buffer = new DataBuffer(); - // target_thread_.task_runner()->PostTaskAndReply( - // FROM_HERE, - // base::Bind(&DataBuffer::AddData, buffer), - // base::Bind(&DataLoader::OnDataReceived, AsWeakPtr(), buffer)); - // } - // - // private: - // void OnDataReceived(scoped_refptr<DataBuffer> buffer) { - // // Do something with buffer. - // } - // }; - // - // - // Things to notice: - // * Results of |task| are shared with |reply| by binding a shared argument - // (a DataBuffer instance). - // * The DataLoader object has no special thread safety. - // * The DataLoader object can be deleted while |task| is still running, - // and the reply will cancel itself safely because it is bound to a - // WeakPtr<>. - bool PostTaskAndReply(const tracked_objects::Location& from_here, - const Closure& task, - const Closure& reply); - - protected: - friend struct TaskRunnerTraits; - - // Only the Windows debug build seems to need this: see - // http://crbug.com/112250. - friend class RefCountedThreadSafe<TaskRunner, TaskRunnerTraits>; - - TaskRunner(); - virtual ~TaskRunner(); - - // Called when this object should be destroyed. By default simply - // deletes |this|, but can be overridden to do something else, like - // delete on a certain thread. - virtual void OnDestruct() const; -}; - -struct BASE_EXPORT TaskRunnerTraits { - static void Destruct(const TaskRunner* task_runner); -}; - -} // namespace base - -#endif // BASE_TASK_RUNNER_H_ |