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Diffstat (limited to 'chromium/base/message_loop/message_loop.h')
| -rw-r--r-- | chromium/base/message_loop/message_loop.h | 201 |
1 files changed, 0 insertions, 201 deletions
diff --git a/chromium/base/message_loop/message_loop.h b/chromium/base/message_loop/message_loop.h deleted file mode 100644 index 84e4c44500f..00000000000 --- a/chromium/base/message_loop/message_loop.h +++ /dev/null @@ -1,201 +0,0 @@ -// Copyright 2013 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_MESSAGE_LOOP_MESSAGE_LOOP_H_ -#define BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_ - -#include <memory> -#include <string> - -#include "base/base_export.h" -#include "base/callback_forward.h" -#include "base/gtest_prod_util.h" -#include "base/macros.h" -#include "base/memory/scoped_refptr.h" -#include "base/message_loop/message_pump_type.h" -#include "base/message_loop/timer_slack.h" -#include "base/pending_task.h" -#include "base/run_loop.h" -#include "base/threading/thread_checker.h" -#include "base/time/time.h" -#include "build/build_config.h" - -namespace base { - -class MessagePump; -class TaskObserver; - -namespace sequence_manager { -class TaskQueue; -namespace internal { -class SequenceManagerImpl; -} // namespace internal -} // namespace sequence_manager - -// A MessageLoop is used to process events for a particular thread. There is -// at most one MessageLoop instance per thread. -// -// Events include at a minimum Task instances submitted to the MessageLoop's -// TaskRunner. Depending on the Type of message pump used by the MessageLoop -// other events such as UI messages may be processed. On Windows APC calls (as -// time permits) and signals sent to a registered set of HANDLEs may also be -// processed. -// -// The MessageLoop's API should only be used directly by its owner (and users -// which the owner opts to share a MessageLoop* with). Other ways to access -// subsets of the MessageLoop API: -// - base::RunLoop : Drive the MessageLoop from the thread it's bound to. -// - base::Thread/SequencedTaskRunnerHandle : Post back to the MessageLoop -// from a task running on it. -// - SequenceLocalStorageSlot : Bind external state to this MessageLoop. -// - base::MessageLoopCurrent : Access statically exposed APIs of this -// MessageLoop. -// - Embedders may provide their own static accessors to post tasks on -// specific loops (e.g. content::BrowserThreads). -// -// NOTE: Unless otherwise specified, a MessageLoop's methods may only be called -// on the thread where the MessageLoop's Run method executes. -// -// NOTE: MessageLoop has task reentrancy protection. This means that if a -// task is being processed, a second task cannot start until the first task is -// finished. Reentrancy can happen when processing a task, and an inner -// message pump is created. That inner pump then processes native messages -// which could implicitly start an inner task. Inner message pumps are created -// with dialogs (DialogBox), common dialogs (GetOpenFileName), OLE functions -// (DoDragDrop), printer functions (StartDoc) and *many* others. -// -// Sample workaround when inner task processing is needed: -// HRESULT hr; -// { -// MessageLoopCurrent::ScopedNestableTaskAllower allow; -// hr = DoDragDrop(...); // Implicitly runs a modal message loop. -// } -// // Process |hr| (the result returned by DoDragDrop()). -// -// Please be SURE your task is reentrant (nestable) and all global variables -// are stable and accessible before calling SetNestableTasksAllowed(true). -// -// DEPRECATED: Use a SingleThreadTaskExecutor instead or TaskEnvironment -// for tests. TODO(https://crbug.com/891670/) remove this class. -class BASE_EXPORT MessageLoop { - public: - // Normally, it is not necessary to instantiate a MessageLoop. Instead, it - // is typical to make use of the current thread's MessageLoop instance. - explicit MessageLoop(MessagePumpType type = MessagePumpType::DEFAULT); - // Creates a MessageLoop with the supplied MessagePump, which must be - // non-null. - explicit MessageLoop(std::unique_ptr<MessagePump> custom_pump); - - virtual ~MessageLoop(); - - // Set the timer slack for this message loop. - void SetTimerSlack(TimerSlack timer_slack); - - // Returns true if this loop's pump is |type|. This allows subclasses - // (especially those in tests) to specialize how they are identified. - virtual bool IsType(MessagePumpType type) const; - - // Returns the type passed to the constructor. - MessagePumpType type() const { return type_; } - - // Sets a new TaskRunner for this message loop. If the message loop was - // already bound, this must be called on the thread to which it is bound. - void SetTaskRunner(scoped_refptr<SingleThreadTaskRunner> task_runner); - - // Gets the TaskRunner associated with this message loop. - scoped_refptr<SingleThreadTaskRunner> task_runner() const; - - // These functions can only be called on the same thread that |this| is - // running on. - // These functions must not be called from a TaskObserver callback. - void AddTaskObserver(TaskObserver* task_observer); - void RemoveTaskObserver(TaskObserver* task_observer); - - // Returns true if the message loop is idle (ignoring delayed tasks). This is - // the same condition which triggers DoWork() to return false: i.e. - // out of tasks which can be processed at the current run-level -- there might - // be deferred non-nestable tasks remaining if currently in a nested run - // level. - // TODO(alexclarke): Make this const when MessageLoopImpl goes away. - bool IsIdleForTesting(); - - //---------------------------------------------------------------------------- - protected: - // Returns true if this is the active MessageLoop for the current thread. - bool IsBoundToCurrentThread() const; - - using MessagePumpFactoryCallback = - OnceCallback<std::unique_ptr<MessagePump>()>; - - // Common protected constructor. Other constructors delegate the - // initialization to this constructor. - // A subclass can invoke this constructor to create a message_loop of a - // specific type with a custom loop. The implementation does not call - // BindToCurrentThread. If this constructor is invoked directly by a subclass, - // then the subclass must subsequently bind the message loop. - MessageLoop(MessagePumpType type, std::unique_ptr<MessagePump> pump); - - // Configure various members and bind this message loop to the current thread. - void BindToCurrentThread(); - - // A raw pointer to the MessagePump handed-off to |sequence_manager_|. - // Valid for the lifetime of |sequence_manager_|. - MessagePump* pump_ = nullptr; - - // TODO(crbug.com/891670): We shouldn't publicly expose all of - // SequenceManagerImpl. - const std::unique_ptr<sequence_manager::internal::SequenceManagerImpl> - sequence_manager_; - // SequenceManager requires an explicit initialisation of the default task - // queue. - const scoped_refptr<sequence_manager::TaskQueue> default_task_queue_; - - private: - friend class MessageLoopTypedTest; - friend class ScheduleWorkTest; - friend class Thread; - friend class sequence_manager::internal::SequenceManagerImpl; - FRIEND_TEST_ALL_PREFIXES(MessageLoopTest, DeleteUnboundLoop); - - // Creates a MessageLoop without binding to a thread. - // - // It is valid to call this to create a new message loop on one thread, - // and then pass it to the thread where the message loop actually runs. - // The message loop's BindToCurrentThread() method must be called on the - // thread the message loop runs on, before calling Run(). - // Before BindToCurrentThread() is called, only Post*Task() functions can - // be called on the message loop. - static std::unique_ptr<MessageLoop> CreateUnbound(MessagePumpType type); - static std::unique_ptr<MessageLoop> CreateUnbound( - std::unique_ptr<MessagePump> pump); - - scoped_refptr<sequence_manager::TaskQueue> CreateDefaultTaskQueue(); - - std::unique_ptr<MessagePump> CreateMessagePump(); - - sequence_manager::internal::SequenceManagerImpl* GetSequenceManagerImpl() - const { - return sequence_manager_.get(); - } - - const MessagePumpType type_; - - // If set this will be returned by the next call to CreateMessagePump(). - // This is only set if |type_| is TYPE_CUSTOM and |pump_| is null. - std::unique_ptr<MessagePump> custom_pump_; - - // Id of the thread this message loop is bound to. Initialized once when the - // MessageLoop is bound to its thread and constant forever after. - PlatformThreadId thread_id_ = kInvalidThreadId; - - // Verifies that calls are made on the thread on which BindToCurrentThread() - // was invoked. - THREAD_CHECKER(bound_thread_checker_); - - DISALLOW_COPY_AND_ASSIGN(MessageLoop); -}; - -} // namespace base - -#endif // BASE_MESSAGE_LOOP_MESSAGE_LOOP_H_ |