[NaCl SDK] Support non blocking TCP/UDP

native_client_sdk/src/libraries/nacl_io/event_emitter.h

 /* Copyright (c) 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 LIBRARIES_NACL_IO_EVENT_EMITTER_H_
 #define LIBRARIES_NACL_IO_EVENT_EMITTER_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <set>
 
 #include "nacl_io/error.h"
 
 #include "sdk_util/ref_object.h"
 #include "sdk_util/scoped_ref.h"
 #include "sdk_util/simple_lock.h"
 
 
 namespace nacl_io {
 
 class EventEmitter;
 class EventListener;
 
-// A ref counted object (non POD derived from RefObject) for storing the
-// state of a single signal request.  Requests are unique to any
-// FD/EventListener pair.
-struct EventInfo : public sdk_util::RefObject {
-  // User provied data to be returned on EventListener::Wait
-  uint64_t user_data;
 
-  // Bitfield of POLL events currently signaled.
-  uint32_t events;
+typedef sdk_util::ScopedRef<EventEmitter> ScopedEventEmitter;
+typedef std::map<EventListener*, uint32_t> EventListenerMap_t;
 
-  // Bitfield of POLL events of interest.
-  uint32_t filter;
-
-  // We do not use a ScopedRef to prevent circular references.
-  EventEmitter* emitter;
-  EventListener* listener;
-  uint32_t id;
-};
-
-typedef sdk_util::ScopedRef<EventInfo> ScopedEventInfo;
-
-// Provide comparison for std::map and std::set
-bool operator<(const ScopedEventInfo& src_a, const ScopedEventInfo& src_b);
-
-typedef std::map<int, ScopedEventInfo> EventInfoMap_t;
-typedef std::set<ScopedEventInfo> EventInfoSet_t;
+bool operator<(const ScopedEventEmitter& src_a,
+               const ScopedEventEmitter& src_b);
 
 // EventEmitter
 //
 // The EventEmitter class provides notification of events to EventListeners
 // by registering EventInfo objects and signaling the EventListener
 // whenever thier state is changed.
 //
 // See "Kernel Events" in event_listener.h for additional information.
+
 class EventEmitter : public sdk_util::RefObject {
+ public:
+  // Returns the current state of the emitter as POLL events bitfield.
+  virtual uint32_t GetEventStatus() = 0;
+  sdk_util::SimpleLock& GetLock() { return emitter_lock_; }
+
  protected:
-  // Called automatically prior to delete to inform the EventListeners that
-  // this EventEmitter is abandoning an associated EventInfo.
-  virtual void Destroy();
-
- private:
   // Register or unregister an EventInfo.  The lock of the EventListener
   // associated with this EventInfo must be held prior to calling these
   // functions.  These functions are private to ensure they are called by the
   // EventListener.
-  void RegisterEventInfo(const ScopedEventInfo& info);
-  void UnregisterEventInfo(const ScopedEventInfo& info);
+  void RegisterListener(EventListener* listener, uint32_t events);
+  void UnregisterListener(EventListener* listener);
 
- public:
-  // Returns the current state of the emitter as POLL events bitfield.
-  virtual uint32_t GetEventStatus() = 0;
-
-  // Returns the type of the emitter (compatible with st_mode in stat)
-  virtual int GetType() = 0;
+  // Event lock must be held when this function is called.
+  void RaiseEvents_Locked(uint32_t events);
+  void RegisterListener_Locked(EventListener* listener, uint32_t events);
+  void UnregisterListener_Locked(EventListener* listener);
 
  protected:
-  // Called by the thread causing the Event.
-  void RaiseEvent(uint32_t events);
+  sdk_util::SimpleLock emitter_lock_;
+  EventListenerMap_t listeners_;
 
-  // Provided to allow one EventEmitter to register the same EventInfo with
-  // a child EventEmitter so that they can both signal the EventListener.
-  // Called after registering locally, but while lock is still held.
-  virtual void ChainRegisterEventInfo(const ScopedEventInfo& event);
-
-  // Called before unregistering locally, but while lock is still held.
-  virtual void ChainUnregisterEventInfo(const ScopedEventInfo& event);
-
-private:
-  sdk_util::SimpleLock emitter_lock_;
-  EventInfoSet_t events_;
   friend class EventListener;
+  friend class EventListenerGroup;
+  friend class EventListenerSingle;
 };
 
-typedef sdk_util::ScopedRef<EventEmitter> ScopedEventEmitter;
-
 }  // namespace nacl_io
 
 
 #endif  // LIBRARIES_NACL_IO_EVENT_EMITTER_H_