1 files changed, 176 insertions, 0 deletions
diff --git a/cpp/src/qpid/posix/EventChannel.h b/cpp/src/qpid/posix/EventChannel.h
new file mode 100644
index 0000000000..55fd2ad135
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+++ b/cpp/src/qpid/posix/EventChannel.h
@@ -0,0 +1,176 @@
+#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/ExceptionHolder.h>
+#include <boost/function.hpp>
+#include <memory>
+
+namespace qpid {
+namespace sys {
+
+class Event;
+class EventHandler;
+class EventChannel;
+
+/**
+ * Base class for all Events.
+ */
+class Event
+{
+  public:
+    /** Type for callback when event is dispatched */
+    typedef boost::function0<void> Callback;
+
+    /**
+     * Create an event with optional callback.
+     * Instances of Event are sent directly through the channel.
+     * Derived classes define additional waiting behaviour.
+     *@param cb A callback functor that is invoked when dispatch() is called.
+     */
+    Event(Callback cb = 0) : callback(cb) {}
+
+    virtual ~Event();
+
+    /** Call the callback provided to the constructor, if any. */
+    void dispatch();
+
+    /** True if there was an error processing this event */
+    bool hasError() const;
+
+    /** If hasError() throw the corresponding exception. */
+    void throwIfError() throw(Exception);
+
+  protected:
+    virtual void prepare(EventHandler&);
+    virtual Event* complete(EventHandler&);
+    void setError(const ExceptionHolder& e);
+
+    Callback callback;
+    ExceptionHolder error;
+
+  friend class EventChannel;
+  friend class EventHandler;
+};
+
+template <class BufT>
+class IOEvent : public Event {
+  public:
+    void getDescriptor() const { return descriptor; }
+    size_t getSize() const { return size; }
+    BufT getBuffer() const { return buffer; }
+  
+  protected:
+    IOEvent(int fd, Callback cb, size_t sz, BufT buf) :
+        Event(cb), descriptor(fd), buffer(buf), size(sz) {}
+
+    int descriptor;
+    BufT buffer;
+    size_t size;
+};
+
+/** Asynchronous read event */
+class ReadEvent : public IOEvent<void*>
+{
+  public:
+    explicit ReadEvent(int fd=-1, void* buf=0, size_t sz=0, Callback cb=0) :
+        IOEvent<void*>(fd, cb, sz, buf), received(0) {}
+
+  private:
+    void prepare(EventHandler&);
+    Event* complete(EventHandler&);
+    ssize_t doRead();
+
+    size_t received;
+};
+
+/** Asynchronous write event */
+class WriteEvent : public IOEvent<const void*>
+{
+  public:
+    explicit WriteEvent(int fd=-1, const void* buf=0, size_t sz=0,
+                        Callback cb=0) :
+        IOEvent<const void*>(fd, cb, sz, buf), written(0) {}
+
+  protected:
+    void prepare(EventHandler&);
+    Event* complete(EventHandler&);
+
+  private:
+    ssize_t doWrite();
+    size_t written;
+};
+
+/** Asynchronous socket accept event */
+class AcceptEvent : public Event
+{
+  public:
+    /** Accept a connection on fd. */
+    explicit AcceptEvent(int fd=-1, Callback cb=0) :
+        Event(cb), descriptor(fd), accepted(0) {}
+
+    /** Get descriptor for server socket */
+    int getAcceptedDesscriptor() const { return accepted; }
+
+  private:
+    void prepare(EventHandler&);
+    Event* complete(EventHandler&);
+
+    int descriptor;
+    int accepted;
+};
+
+
+class QueueSet;
+
+/**
+ * Channel to post and wait for events.
+ */
+class EventChannel : public qpid::SharedObject<EventChannel>
+{
+  public:
+    static shared_ptr create();
+    
+    ~EventChannel();
+    
+    /** Post an event to the channel. */
+    void postEvent(Event& event);
+
+    /** Post an event to the channel. Must not be 0. */
+    void postEvent(Event* event) { postEvent(*event); }
+        
+    /**
+     * Wait for the next complete event.
+     *@return Pointer to event. Will never return 0.
+     */
+    Event* getEvent();
+
+  private:
+    EventChannel();
+    boost::shared_ptr<EventHandler> handler;
+};
+
+
+}}
+
+
+
+#endif  /*!_sys_EventChannel_h*/