Move message_pump to base/message_loop.

base/message_pump_mac.h

-// 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.
-
-// The basis for all native run loops on the Mac is the CFRunLoop.  It can be
-// used directly, it can be used as the driving force behind the similar
-// Foundation NSRunLoop, and it can be used to implement higher-level event
-// loops such as the NSApplication event loop.
-//
-// This file introduces a basic CFRunLoop-based implementation of the
-// MessagePump interface called CFRunLoopBase.  CFRunLoopBase contains all
-// of the machinery necessary to dispatch events to a delegate, but does not
-// implement the specific run loop.  Concrete subclasses must provide their
-// own DoRun and Quit implementations.
-//
-// A concrete subclass that just runs a CFRunLoop loop is provided in
-// MessagePumpCFRunLoop.  For an NSRunLoop, the similar MessagePumpNSRunLoop
-// is provided.
-//
-// For the application's event loop, an implementation based on AppKit's
-// NSApplication event system is provided in MessagePumpNSApplication.
-//
-// Typically, MessagePumpNSApplication only makes sense on a Cocoa
-// application's main thread.  If a CFRunLoop-based message pump is needed on
-// any other thread, one of the other concrete subclasses is preferrable.
-// MessagePumpMac::Create is defined, which returns a new NSApplication-based
-// or NSRunLoop-based MessagePump subclass depending on which thread it is
-// called on.
-
-#ifndef BASE_MESSAGE_PUMP_MAC_H_
-#define BASE_MESSAGE_PUMP_MAC_H_
-
-#include "base/message_pump.h"
-
-#include <CoreFoundation/CoreFoundation.h>
-
-#if !defined(__OBJC__)
-class NSAutoreleasePool;
-#else  // !defined(__OBJC__)
-#if defined(OS_IOS)
-#import <Foundation/Foundation.h>
-#else
-#import <AppKit/AppKit.h>
-
-// Clients must subclass NSApplication and implement this protocol if they use
-// MessagePumpMac.
-@protocol CrAppProtocol
-// Must return true if -[NSApplication sendEvent:] is currently on the stack.
-// See the comment for |CreateAutoreleasePool()| in the cc file for why this is
-// necessary.
-- (BOOL)isHandlingSendEvent;
-@end
-#endif  // !defined(OS_IOS)
-#endif  // !defined(__OBJC__)
-
-namespace base {
-
-class RunLoop;
-class TimeTicks;
-
-class MessagePumpCFRunLoopBase : public MessagePump {
-  // Needs access to CreateAutoreleasePool.
-  friend class MessagePumpScopedAutoreleasePool;
- public:
-  MessagePumpCFRunLoopBase();
-
-  // Subclasses should implement the work they need to do in MessagePump::Run
-  // in the DoRun method.  MessagePumpCFRunLoopBase::Run calls DoRun directly.
-  // This arrangement is used because MessagePumpCFRunLoopBase needs to set
-  // up and tear down things before and after the "meat" of DoRun.
-  virtual void Run(Delegate* delegate) OVERRIDE;
-  virtual void DoRun(Delegate* delegate) = 0;
-
-  virtual void ScheduleWork() OVERRIDE;
-  virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time) OVERRIDE;
-
- protected:
-  virtual ~MessagePumpCFRunLoopBase();
-
-  // Accessors for private data members to be used by subclasses.
-  CFRunLoopRef run_loop() const { return run_loop_; }
-  int nesting_level() const { return nesting_level_; }
-  int run_nesting_level() const { return run_nesting_level_; }
-
-  // Sets this pump's delegate.  Signals the appropriate sources if
-  // |delegateless_work_| is true.  |delegate| can be NULL.
-  void SetDelegate(Delegate* delegate);
-
-  // Return an autorelease pool to wrap around any work being performed.
-  // In some cases, CreateAutoreleasePool may return nil intentionally to
-  // preventing an autorelease pool from being created, allowing any
-  // objects autoreleased by work to fall into the current autorelease pool.
-  virtual NSAutoreleasePool* CreateAutoreleasePool();
-
- private:
-  // Timer callback scheduled by ScheduleDelayedWork.  This does not do any
-  // work, but it signals work_source_ so that delayed work can be performed
-  // within the appropriate priority constraints.
-  static void RunDelayedWorkTimer(CFRunLoopTimerRef timer, void* info);
-
-  // Perform highest-priority work.  This is associated with work_source_
-  // signalled by ScheduleWork or RunDelayedWorkTimer.  The static method calls
-  // the instance method; the instance method returns true if it resignalled
-  // work_source_ to be called again from the loop.
-  static void RunWorkSource(void* info);
-  bool RunWork();
-
-  // Perform idle-priority work.  This is normally called by PreWaitObserver,
-  // but is also associated with idle_work_source_.  When this function
-  // actually does perform idle work, it will resignal that source.  The
-  // static method calls the instance method; the instance method returns
-  // true if idle work was done.
-  static void RunIdleWorkSource(void* info);
-  bool RunIdleWork();
-
-  // Perform work that may have been deferred because it was not runnable
-  // within a nested run loop.  This is associated with
-  // nesting_deferred_work_source_ and is signalled by
-  // MaybeScheduleNestingDeferredWork when returning from a nested loop,
-  // so that an outer loop will be able to perform the necessary tasks if it
-  // permits nestable tasks.
-  static void RunNestingDeferredWorkSource(void* info);
-  bool RunNestingDeferredWork();
-
-  // Schedules possible nesting-deferred work to be processed before the run
-  // loop goes to sleep, exits, or begins processing sources at the top of its
-  // loop.  If this function detects that a nested loop had run since the
-  // previous attempt to schedule nesting-deferred work, it will schedule a
-  // call to RunNestingDeferredWorkSource.
-  void MaybeScheduleNestingDeferredWork();
-
-  // Observer callback responsible for performing idle-priority work, before
-  // the run loop goes to sleep.  Associated with idle_work_observer_.
-  static void PreWaitObserver(CFRunLoopObserverRef observer,
-                              CFRunLoopActivity activity, void* info);
-
-  // Observer callback called before the run loop processes any sources.
-  // Associated with pre_source_observer_.
-  static void PreSourceObserver(CFRunLoopObserverRef observer,
-                                CFRunLoopActivity activity, void* info);
-
-  // Observer callback called when the run loop starts and stops, at the
-  // beginning and end of calls to CFRunLoopRun.  This is used to maintain
-  // nesting_level_.  Associated with enter_exit_observer_.
-  static void EnterExitObserver(CFRunLoopObserverRef observer,
-                                CFRunLoopActivity activity, void* info);
-
-  // Called by EnterExitObserver after performing maintenance on nesting_level_.
-  // This allows subclasses an opportunity to perform additional processing on
-  // the basis of run loops starting and stopping.
-  virtual void EnterExitRunLoop(CFRunLoopActivity activity);
-
-  // The thread's run loop.
-  CFRunLoopRef run_loop_;
-
-  // The timer, sources, and observers are described above alongside their
-  // callbacks.
-  CFRunLoopTimerRef delayed_work_timer_;
-  CFRunLoopSourceRef work_source_;
-  CFRunLoopSourceRef idle_work_source_;
-  CFRunLoopSourceRef nesting_deferred_work_source_;
-  CFRunLoopObserverRef pre_wait_observer_;
-  CFRunLoopObserverRef pre_source_observer_;
-  CFRunLoopObserverRef enter_exit_observer_;
-
-  // (weak) Delegate passed as an argument to the innermost Run call.
-  Delegate* delegate_;
-
-  // The time that delayed_work_timer_ is scheduled to fire.  This is tracked
-  // independently of CFRunLoopTimerGetNextFireDate(delayed_work_timer_)
-  // to be able to reset the timer properly after waking from system sleep.
-  // See PowerStateNotification.
-  CFAbsoluteTime delayed_work_fire_time_;
-
-  // The recursion depth of the currently-executing CFRunLoopRun loop on the
-  // run loop's thread.  0 if no run loops are running inside of whatever scope
-  // the object was created in.
-  int nesting_level_;
-
-  // The recursion depth (calculated in the same way as nesting_level_) of the
-  // innermost executing CFRunLoopRun loop started by a call to Run.
-  int run_nesting_level_;
-
-  // The deepest (numerically highest) recursion depth encountered since the
-  // most recent attempt to run nesting-deferred work.
-  int deepest_nesting_level_;
-
-  // "Delegateless" work flags are set when work is ready to be performed but
-  // must wait until a delegate is available to process it.  This can happen
-  // when a MessagePumpCFRunLoopBase is instantiated and work arrives without
-  // any call to Run on the stack.  The Run method will check for delegateless
-  // work on entry and redispatch it as needed once a delegate is available.
-  bool delegateless_work_;
-  bool delegateless_idle_work_;
-
-  DISALLOW_COPY_AND_ASSIGN(MessagePumpCFRunLoopBase);
-};
-
-class MessagePumpCFRunLoop : public MessagePumpCFRunLoopBase {
- public:
-  MessagePumpCFRunLoop();
-
-  virtual void DoRun(Delegate* delegate) OVERRIDE;
-  virtual void Quit() OVERRIDE;
-
- protected:
-  virtual ~MessagePumpCFRunLoop();
-
- private:
-  virtual void EnterExitRunLoop(CFRunLoopActivity activity) OVERRIDE;
-
-  // True if Quit is called to stop the innermost MessagePump
-  // (innermost_quittable_) but some other CFRunLoopRun loop (nesting_level_)
-  // is running inside the MessagePump's innermost Run call.
-  bool quit_pending_;
-
-  DISALLOW_COPY_AND_ASSIGN(MessagePumpCFRunLoop);
-};
-
-class MessagePumpNSRunLoop : public MessagePumpCFRunLoopBase {
- public:
-  BASE_EXPORT MessagePumpNSRunLoop();
-
-  virtual void DoRun(Delegate* delegate) OVERRIDE;
-  virtual void Quit() OVERRIDE;
-
- protected:
-  virtual ~MessagePumpNSRunLoop();
-
- private:
-  // A source that doesn't do anything but provide something signalable
-  // attached to the run loop.  This source will be signalled when Quit
-  // is called, to cause the loop to wake up so that it can stop.
-  CFRunLoopSourceRef quit_source_;
-
-  // False after Quit is called.
-  bool keep_running_;
-
-  DISALLOW_COPY_AND_ASSIGN(MessagePumpNSRunLoop);
-};
-
-#if defined(OS_IOS)
-// This is a fake message pump.  It attaches sources to the main thread's
-// CFRunLoop, so PostTask() will work, but it is unable to drive the loop
-// directly, so calling Run() or Quit() are errors.
-class MessagePumpUIApplication : public MessagePumpCFRunLoopBase {
- public:
-  MessagePumpUIApplication();
-  virtual void DoRun(Delegate* delegate) OVERRIDE;
-  virtual void Quit() OVERRIDE;
-
-  // This message pump can not spin the main message loop directly.  Instead,
-  // call |Attach()| to set up a delegate.  It is an error to call |Run()|.
-  virtual void Attach(Delegate* delegate);
-
- protected:
-  virtual ~MessagePumpUIApplication();
-
- private:
-  base::RunLoop* run_loop_;
-
-  DISALLOW_COPY_AND_ASSIGN(MessagePumpUIApplication);
-};
-
-#else
-
-class MessagePumpNSApplication : public MessagePumpCFRunLoopBase {
- public:
-  MessagePumpNSApplication();
-
-  virtual void DoRun(Delegate* delegate) OVERRIDE;
-  virtual void Quit() OVERRIDE;
-
- protected:
-  virtual ~MessagePumpNSApplication();
-
- private:
-  // False after Quit is called.
-  bool keep_running_;
-
-  // True if DoRun is managing its own run loop as opposed to letting
-  // -[NSApplication run] handle it.  The outermost run loop in the application
-  // is managed by -[NSApplication run], inner run loops are handled by a loop
-  // in DoRun.
-  bool running_own_loop_;
-
-  DISALLOW_COPY_AND_ASSIGN(MessagePumpNSApplication);
-};
-
-class MessagePumpCrApplication : public MessagePumpNSApplication {
- public:
-  MessagePumpCrApplication();
-
- protected:
-  virtual ~MessagePumpCrApplication() {}
-
-  // Returns nil if NSApp is currently in the middle of calling
-  // -sendEvent.  Requires NSApp implementing CrAppProtocol.
-  virtual NSAutoreleasePool* CreateAutoreleasePool() OVERRIDE;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(MessagePumpCrApplication);
-};
-#endif  // !defined(OS_IOS)
-
-class MessagePumpMac {
- public:
-  // If not on the main thread, returns a new instance of
-  // MessagePumpNSRunLoop.
-  //
-  // On the main thread, if NSApp exists and conforms to
-  // CrAppProtocol, creates an instances of MessagePumpCrApplication.
-  //
-  // Otherwise creates an instance of MessagePumpNSApplication using a
-  // default NSApplication.
-  static MessagePump* Create();
-
-#if !defined(OS_IOS)
-  // If a pump is created before the required CrAppProtocol is
-  // created, the wrong MessagePump subclass could be used.
-  // UsingCrApp() returns false if the message pump was created before
-  // NSApp was initialized, or if NSApp does not implement
-  // CrAppProtocol.  NSApp must be initialized before calling.
-  BASE_EXPORT static bool UsingCrApp();
-
-  // Wrapper to query -[NSApp isHandlingSendEvent] from C++ code.
-  // Requires NSApp to implement CrAppProtocol.
-  BASE_EXPORT static bool IsHandlingSendEvent();
-#endif  // !defined(OS_IOS)
-
- private:
-  DISALLOW_IMPLICIT_CONSTRUCTORS(MessagePumpMac);
-};
-
-}  // namespace base
-
-#endif  // BASE_MESSAGE_PUMP_MAC_H_