Provide an iOS message pump for IO implementation.

base/message_pump_io_ios.h

-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 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_MESSAGE_PUMP_LIBEVENT_H_
-#define BASE_MESSAGE_PUMP_LIBEVENT_H_
+#ifndef BASE_MESSAGE_PUMP_IO_IOS_H_
+#define BASE_MESSAGE_PUMP_IO_IOS_H_
 
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
+#include "base/base_export.h"
+#include "base/mac/scoped_cffiledescriptorref.h"
+#include "base/mac/scoped_cftyperef.h"
 #include "base/memory/weak_ptr.h"
-#include "base/message_pump.h"
+#include "base/message_pump_mac.h"
 #include "base/observer_list.h"
-#include "base/threading/thread_checker.h"
-#include "base/time.h"
-
-// Declare structs we need from libevent.h rather than including it
-struct event_base;
-struct event;
 
 namespace base {
 
-// Class to monitor sockets and issue callbacks when sockets are ready for I/O
-// TODO(dkegel): add support for background file IO somehow
-class BASE_EXPORT MessagePumpLibevent : public MessagePump {
+// This file introduces a class to monitor sockets and issue callbacks when
+// sockets are ready for I/O on iOS.
+class BASE_EXPORT MessagePumpIOSForIO : public MessagePumpNSRunLoop {
  public:
   class IOObserver {
    public:
     IOObserver() {}
 
     // An IOObserver is an object that receives IO notifications from the
     // MessagePump.
     //
     // NOTE: An IOObserver implementation should be extremely fast!
     virtual void WillProcessIOEvent() = 0;
     virtual void DidProcessIOEvent() = 0;
 
    protected:
     virtual ~IOObserver() {}
   };
 
-  class FileDescriptorWatcher;
-
-  // Used with WatchFileDescriptor to asynchronously monitor the I/O readiness
-  // of a file descriptor.
+  // Used with WatchFileDescptor to asynchronously monitor the I/O readiness of
+  // a File Descriptor.

[wtc, 2012/11/29 00:53:21]

Don't capitalize "File Descriptor".

[blundell, 2012/11/29 15:01:04]

Done.

   class Watcher {
    public:
+    virtual ~Watcher() {}

[wtc, 2012/11/29 00:53:21]

In MessagePumpLibevent, ~Watcher() is protected. Should we
do the same here?

[blundell, 2012/11/29 15:01:04]

Done.

+
     // Called from MessageLoop::Run when an FD can be read from/written to
     // without blocking
     virtual void OnFileCanReadWithoutBlocking(int fd) = 0;
     virtual void OnFileCanWriteWithoutBlocking(int fd) = 0;
-
-   protected:
-    virtual ~Watcher() {}
   };
 
   // Object returned by WatchFileDescriptor to manage further watching.
   class FileDescriptorWatcher {
    public:
     FileDescriptorWatcher();
     ~FileDescriptorWatcher();  // Implicitly calls StopWatchingFileDescriptor.
 
     // NOTE: These methods aren't called StartWatching()/StopWatching() to
     // avoid confusion with the win32 ObjectWatcher class.
 
     // Stop watching the FD, always safe to call.  No-op if there's nothing
     // to do.
     bool StopWatchingFileDescriptor();
 
    private:
-    friend class MessagePumpLibevent;
-    friend class MessagePumpLibeventTest;
+    friend class MessagePumpIOSForIO;
+    friend class MessagePumpIOSForIOTest;
 
-    // Called by MessagePumpLibevent, ownership of |e| is transferred to this
-    // object.
-    void Init(event* e);
+    // Called by MessagePumpIOSForIO, ownership of |fdref| and |fd_source|
+    // is transferred to this object.
+    void Init(CFFileDescriptorRef fdref,
+              CFOptionFlags callback_types,
+              CFRunLoopSourceRef fd_source,
+              bool is_persistent);
 
-    // Used by MessagePumpLibevent to take ownership of event_.
-    event* ReleaseEvent();
-
-    void set_pump(MessagePumpLibevent* pump) { pump_ = pump; }
-    MessagePumpLibevent* pump() { return pump_; }
+    void set_pump(MessagePumpIOSForIO* pump) { pump_ = pump; }
+    MessagePumpIOSForIO* pump() const { return pump_; }
 
     void set_watcher(Watcher* watcher) { watcher_ = watcher; }
 
-    void OnFileCanReadWithoutBlocking(int fd, MessagePumpLibevent* pump);
-    void OnFileCanWriteWithoutBlocking(int fd, MessagePumpLibevent* pump);
+    void OnFileCanReadWithoutBlocking(int fd, MessagePumpIOSForIO* pump);
+    void OnFileCanWriteWithoutBlocking(int fd, MessagePumpIOSForIO* pump);
 
-    event* event_;
-    MessagePumpLibevent* pump_;
+    bool is_persistent_;  // false if this event is one-shot.
+    base::mac::ScopedCFFileDescriptorRef fdref_;
+    CFOptionFlags callback_types_;
+    base::mac::ScopedCFTypeRef<CFRunLoopSourceRef> fd_source_;
+    MessagePumpIOSForIO* pump_;
     Watcher* watcher_;
     base::WeakPtrFactory<FileDescriptorWatcher> weak_factory_;
 
     DISALLOW_COPY_AND_ASSIGN(FileDescriptorWatcher);
   };
 
   enum Mode {
     WATCH_READ = 1 << 0,
     WATCH_WRITE = 1 << 1,
     WATCH_READ_WRITE = WATCH_READ | WATCH_WRITE
   };
 
-  MessagePumpLibevent();
+  MessagePumpIOSForIO();
 
   // Have the current thread's message loop watch for a a situation in which
   // reading/writing to the FD can be performed without blocking.
   // Callers must provide a preallocated FileDescriptorWatcher object which
   // can later be used to manage the lifetime of this event.
   // If a FileDescriptorWatcher is passed in which is already attached to
   // an event, then the effect is cumulative i.e. after the call |controller|
   // will watch both the previous event and the new one.
   // If an error occurs while calling this method in a cumulative fashion, the
   // event previously attached to |controller| is aborted.
   // Returns true on success.
   // Must be called on the same thread the message_pump is running on.
-  // TODO(dkegel): switch to edge-triggered readiness notification
   bool WatchFileDescriptor(int fd,
                            bool persistent,
-                           Mode mode,
+                           int mode,
                            FileDescriptorWatcher *controller,
                            Watcher *delegate);
 
+  void RemoveRunLoopSource(CFRunLoopSourceRef source);
+
   void AddIOObserver(IOObserver* obs);
   void RemoveIOObserver(IOObserver* obs);
 
-  // MessagePump methods:
-  virtual void Run(Delegate* delegate) OVERRIDE;
-  virtual void Quit() OVERRIDE;
-  virtual void ScheduleWork() OVERRIDE;
-  virtual void ScheduleDelayedWork(const TimeTicks& delayed_work_time) OVERRIDE;
-
  protected:
-  virtual ~MessagePumpLibevent();
+  virtual ~MessagePumpIOSForIO();
 
  private:
-  friend class MessagePumpLibeventTest;
+  friend class MessagePumpIOSForIOTest;
 
   void WillProcessIOEvent();
   void DidProcessIOEvent();
 
-  // Risky part of constructor.  Returns true on success.
-  bool Init();
-
-  // Called by libevent to tell us a registered FD can be read/written to.
-  static void OnLibeventNotification(int fd, short flags,
-                                     void* context);
-
-  // Unix pipe used to implement ScheduleWork()
-  // ... callback; called by libevent inside Run() when pipe is ready to read
-  static void OnWakeup(int socket, short flags, void* context);
-
-  // This flag is set to false when Run should return.
-  bool keep_running_;
-
-  // This flag is set when inside Run.
-  bool in_run_;
-
-  // This flag is set if libevent has processed I/O events.
-  bool processed_io_events_;
-
-  // The time at which we should call DoDelayedWork.
-  TimeTicks delayed_work_time_;
-
-  // Libevent dispatcher.  Watches all sockets registered with it, and sends
-  // readiness callbacks when a socket is ready for I/O.
-  event_base* event_base_;
-
-  // ... write end; ScheduleWork() writes a single byte to it
-  int wakeup_pipe_in_;
-  // ... read end; OnWakeup reads it and then breaks Run() out of its sleep
-  int wakeup_pipe_out_;
-  // ... libevent wrapper for read end
-  event* wakeup_event_;
+  static void HandleFdIOEvent(CFFileDescriptorRef fdref,
+                              CFOptionFlags callback_types,
+                              void* context);
 
   ObserverList<IOObserver> io_observers_;
   ThreadChecker watch_file_descriptor_caller_checker_;
-  DISALLOW_COPY_AND_ASSIGN(MessagePumpLibevent);
+
+  DISALLOW_COPY_AND_ASSIGN(MessagePumpIOSForIO);
 };
 
 }  // namespace base
 
-#endif  // BASE_MESSAGE_PUMP_LIBEVENT_H_
+#endif // BASE_MESSAGE_PUMP_IO_IOS_H_

[wtc, 2012/11/29 00:53:21]

Add a space before "//".

[blundell, 2012/11/29 15:01:04]

Done.