base/message_loop/message_pump_io_ios.h

   1 // Copyright 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 #ifndef BASE_MESSAGE_LOOP_MESSAGE_PUMP_IO_IOS_H_
   6 #define BASE_MESSAGE_LOOP_MESSAGE_PUMP_IO_IOS_H_
   7
   8 #include "base/base_export.h"
   9 #include "base/mac/scoped_cffiledescriptorref.h"
  10 #include "base/mac/scoped_cftyperef.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "base/message_loop/message_pump_mac.h"
  14 #include "base/observer_list.h"
  15 #include "base/threading/thread_checker.h"
  16
  17 namespace base {
  18
  19 // This file introduces a class to monitor sockets and issue callbacks when
  20 // sockets are ready for I/O on iOS.
  21 class BASE_EXPORT MessagePumpIOSForIO : public MessagePumpNSRunLoop {
  22  public:
  23   class IOObserver {
  24    public:
  25     IOObserver() {}
  26
  27     // An IOObserver is an object that receives IO notifications from the
  28     // MessagePump.
  29     //
  30     // NOTE: An IOObserver implementation should be extremely fast!
  31     virtual void WillProcessIOEvent() = 0;
  32     virtual void DidProcessIOEvent() = 0;
  33
  34    protected:
  35     virtual ~IOObserver() {}
  36   };
  37
  38   // Used with WatchFileDescriptor to asynchronously monitor the I/O readiness
  39   // of a file descriptor.
  40   class Watcher {
  41    public:
  42     // Called from MessageLoop::Run when an FD can be read from/written to
  43     // without blocking
  44     virtual void OnFileCanReadWithoutBlocking(int fd) = 0;
  45     virtual void OnFileCanWriteWithoutBlocking(int fd) = 0;
  46
  47    protected:
  48     virtual ~Watcher() {}
  49   };
  50
  51   // Object returned by WatchFileDescriptor to manage further watching.
  52   class FileDescriptorWatcher {
  53    public:
  54     FileDescriptorWatcher();
  55     ~FileDescriptorWatcher();  // Implicitly calls StopWatchingFileDescriptor.
  56
  57     // NOTE: These methods aren't called StartWatching()/StopWatching() to
  58     // avoid confusion with the win32 ObjectWatcher class.
  59
  60     // Stop watching the FD, always safe to call.  No-op if there's nothing
  61     // to do.
  62     bool StopWatchingFileDescriptor();
  63
  64    private:
  65     friend class MessagePumpIOSForIO;
  66     friend class MessagePumpIOSForIOTest;
  67
  68     // Called by MessagePumpIOSForIO, ownership of |fdref| and |fd_source|
  69     // is transferred to this object.
  70     void Init(CFFileDescriptorRef fdref,
  71               CFOptionFlags callback_types,
  72               CFRunLoopSourceRef fd_source,
  73               bool is_persistent);
  74
  75     void set_pump(base::WeakPtr<MessagePumpIOSForIO> pump) { pump_ = pump; }
  76     const base::WeakPtr<MessagePumpIOSForIO>& pump() const { return pump_; }
  77
  78     void set_watcher(Watcher* watcher) { watcher_ = watcher; }
  79
  80     void OnFileCanReadWithoutBlocking(int fd, MessagePumpIOSForIO* pump);
  81     void OnFileCanWriteWithoutBlocking(int fd, MessagePumpIOSForIO* pump);
  82
  83     bool is_persistent_;  // false if this event is one-shot.
  84     base::mac::ScopedCFFileDescriptorRef fdref_;
  85     CFOptionFlags callback_types_;
  86     base::ScopedCFTypeRef<CFRunLoopSourceRef> fd_source_;
  87     base::WeakPtr<MessagePumpIOSForIO> pump_;
  88     Watcher* watcher_;
  89
  90     DISALLOW_COPY_AND_ASSIGN(FileDescriptorWatcher);
  91   };
  92
  93   enum Mode {
  94     WATCH_READ = 1 << 0,
  95     WATCH_WRITE = 1 << 1,
  96     WATCH_READ_WRITE = WATCH_READ | WATCH_WRITE
  97   };
  98
  99   MessagePumpIOSForIO();
 100   virtual ~MessagePumpIOSForIO();
 101
 102   // Have the current thread's message loop watch for a a situation in which
 103   // reading/writing to the FD can be performed without blocking.
 104   // Callers must provide a preallocated FileDescriptorWatcher object which
 105   // can later be used to manage the lifetime of this event.
 106   // If a FileDescriptorWatcher is passed in which is already attached to
 107   // an event, then the effect is cumulative i.e. after the call |controller|
 108   // will watch both the previous event and the new one.
 109   // If an error occurs while calling this method in a cumulative fashion, the
 110   // event previously attached to |controller| is aborted.
 111   // Returns true on success.
 112   // Must be called on the same thread the message_pump is running on.
 113   bool WatchFileDescriptor(int fd,
 114                            bool persistent,
 115                            int mode,
 116                            FileDescriptorWatcher *controller,
 117                            Watcher *delegate);
 118
 119   void RemoveRunLoopSource(CFRunLoopSourceRef source);
 120
 121   void AddIOObserver(IOObserver* obs);
 122   void RemoveIOObserver(IOObserver* obs);
 123
 124  private:
 125   friend class MessagePumpIOSForIOTest;
 126
 127   void WillProcessIOEvent();
 128   void DidProcessIOEvent();
 129
 130   static void HandleFdIOEvent(CFFileDescriptorRef fdref,
 131                               CFOptionFlags callback_types,
 132                               void* context);
 133
 134   ObserverList<IOObserver> io_observers_;
 135   ThreadChecker watch_file_descriptor_caller_checker_;
 136
 137   base::WeakPtrFactory<MessagePumpIOSForIO> weak_factory_;
 138
 139   DISALLOW_COPY_AND_ASSIGN(MessagePumpIOSForIO);
 140 };
 141
 142 }  // namespace base
 143
 144 #endif  // BASE_MESSAGE_LOOP_MESSAGE_PUMP_IO_IOS_H_