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diff --git a/cpp/src/qpid/sys/EventChannel.h b/cpp/src/qpid/sys/EventChannel.h
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+++ b/cpp/src/qpid/sys/EventChannel.h
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+#ifndef _sys_EventChannel_h
+#define _sys_EventChannel_h
+
+/*
+ *
+ * Copyright (c) 2006 The Apache Software Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <qpid/SharedObject.h>
+#include <qpid/Exception.h>
+#include <qpid/sys/Time.h>
+
+namespace qpid {
+namespace sys {
+
+class EventChannel;
+
+class Event;
+class ReadEvent;
+class WriteEvent;
+class AcceptEvent;
+class NotifyEvent;
+
+/**
+   Active event channel. Events represent async IO requests or
+   inter-task synchronization. Posting an Event registers interest in
+   the IO or sync event. When it occurs the posted Event is 
+   corresponding IO or sync event occurs they are returned to one
+   of the threads waiting on the channel. For more details see
+   the Event hierarchy.
+*/
+class EventChannel : public qpid::SharedObject<EventChannel>
+{
+  public:
+    static EventChannel::shared_ptr create();
+    
+    virtual ~EventChannel() {}
+
+    virtual void post(ReadEvent& event) = 0;
+    virtual void post(WriteEvent& event) = 0;
+    virtual void post(AcceptEvent& event) = 0;
+    virtual void post(NotifyEvent& event) = 0;
+
+    inline void post(Event& event);
+
+    /**
+     * Wait for the next completed event.
+     * @return An Event or 0 to indicate the calling thread should shut down.
+     */
+    virtual Event* getEvent() = 0;
+
+    /** Dispose of a system-allocated buffer. Called by ReadEvent */
+    virtual void dispose(void* buffer, size_t size) = 0;
+    
+  protected:
+    EventChannel() {}
+};
+
+
+/**
+ * Base class for all events. There are two possible styles of use:
+ *
+ * Task style: the event is allocated as a local variable on the initiating
+ * task, which blocks in wait(). Event::dispatch() resumes that task
+ * with the event data available.
+ *
+ * Proactor style: Threads post events but do not
+ * wait. Event::dispatch() processes the event in the dispatching
+ * thread and then deletes itself.
+ *
+ * Tasks give less kernel context switching and blocking AND simpler
+ * coding.  Tasks can call any number of pseudo-blocking opereations
+ * that are actually event post/wait pairs. At each such point the
+ * current thread can continue with the task or switch to another task
+ * to minimise blocking.
+ *
+ * With Proactor style dispatch() is an atomic unit of work as far as
+ * the EventChannel is concerned. To avoid such blocking the
+ * application has to be written as a collection of non-blocking
+ * dispatch() callbacks, which is more complex than tasks that can
+ * call pseudo-blocking operations.
+ */
+class Event : private boost::noncopyable 
+{
+  public:
+    virtual ~Event() {}
+
+    /** Post this event to the channel */
+    virtual void post(EventChannel& channel) = 0;
+
+    /**
+     * Block till the event is delivered.
+     * At  most one task can wait on an event.
+     */
+    virtual void wait() const = 0;
+
+    /**
+     * Dispatch the event. Runs some event-specific code, may switch
+     * context to resume a waiting task.
+     */
+    virtual void dispatch() = 0;
+};
+
+    
+/**
+ * Base class for asynchronous request events, provides exception
+ * handling.
+ */
+class RequestEvent : public Event
+{
+  public:
+    /** True if the async request failed */
+    bool hasException() const { return ex.get(); }
+
+    const qpid::Exception& getException() const { return *ex; }
+    
+    void setException(std::auto_ptr<qpid::Exception>& e) { ex = e; }
+
+    /** If the event has an exception throw it, else do nothing */
+    void verify() const { if (ex.get()) throw *ex; }
+
+    void post(EventChannel& channel) { channel.post(*this); }
+
+  private:
+    qpid::HeapException ex;
+};
+
+
+/** An asynchronous read event. */
+class ReadEvent : public RequestEvent {
+  public:
+    /**
+     * Read data from fd.
+     */
+    ReadEvent(int fileDescriptor, void* buffer, size_t bytesToRead) :
+        fd(fileDescriptor), data(buffer), size(bytesToRead) {}
+
+    /** Number of bytes read. */
+    size_t getBytesRead() const { verify(); return size; }
+
+    /**
+     * If the system supports direct access to DMA buffers then
+     * it may provide a direct pointer to such a buffer to avoid
+     * a copy into the user buffer.
+     * @return true if getData() is returning a system-supplied buffer.
+     */
+    bool isSystemData() const { verify(); return channel != 0; }
+
+    /**
+     * Pointer to data read. Note if isSystemData() is true then this
+     * is NOT the same buffer that was supplied to the constructor.
+     * The user buffer is untouched. See dispose().
+     */
+    void* getData() const { verify(); return data; }
+
+    /** Called by the event channel on completion. */
+    void complete(EventChannel::shared_ptr ec, void* _data, size_t _size) {
+        if (data != _data) channel = ec; data = _data; size = _size;
+    }
+
+    /**
+     * Dispose of system-provided data buffer, if any.  This is
+     * automatically called by the destructor.
+     */
+    void dispose() { if(channel && data) channel->dispose(data,size); data=0; }
+
+    ~ReadEvent() { dispose(); }
+
+    void post(EventChannel& channel) { channel.post(*this); }
+
+  private:
+    int fd;
+    void* data;
+    size_t size;
+    EventChannel::shared_ptr channel;
+};
+
+/** Asynchronous write event */
+class WriteEvent : public RequestEvent {
+  public:
+    WriteEvent(int fileDescriptor, void* buffer, size_t bytesToWrite) :
+        fd(fileDescriptor), data(buffer), size(bytesToWrite) {}
+
+    /** Number of bytes written */
+    size_t getBytesWritten() const { verify(); return size; }
+
+    void post(EventChannel& channel) { channel.post(*this); }
+
+  private:
+    int fd;
+    void*  data;
+    size_t size;
+};
+
+/** Asynchronous socket accept event */
+class AcceptEvent : public RequestEvent {
+  public:
+    /** Accept a connection on listeningFd */
+    AcceptEvent(int listeningFd) : listen(listeningFd) {}
+
+    /** Get accepted file descriptor */
+    int getAcceptedFd() const { verify(); return accepted; }
+
+    void post(EventChannel& channel) { channel.post(*this); }
+
+  private:
+    int listen;
+    int accepted;
+};
+
+/**
+ * NotifyEvent is delievered immediately to be dispatched by an
+ * EventChannel thread.
+ */
+class NotifyEvent : public RequestEvent {
+  public:
+    void post(EventChannel& channel) { channel.post(*this); }
+};
+
+
+inline void EventChannel::post(Event& event) { event.post(*this); }
+
+}}
+
+
+#endif  /*!_sys_EventChannel_h*/