1 files changed, 229 insertions, 0 deletions
diff --git a/cpp/lib/common/sys/posix/EventChannelConnection.cpp b/cpp/lib/common/sys/posix/EventChannelConnection.cpp
new file mode 100644
index 0000000000..196dde5af8
--- /dev/null
+++ b/cpp/lib/common/sys/posix/EventChannelConnection.cpp
@@ -0,0 +1,229 @@
+/*
+ *
+ * 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 <iostream>
+
+#include <boost/bind.hpp>
+#include <boost/assert.hpp>
+
+#include "EventChannelConnection.h"
+#include "sys/SessionHandlerFactory.h"
+#include "QpidError.h"
+
+using namespace std;
+using namespace qpid;
+using namespace qpid::framing;
+
+namespace qpid {
+namespace sys {
+
+const size_t EventChannelConnection::bufferSize = 65536;
+    
+EventChannelConnection::EventChannelConnection(
+    EventChannelThreads::shared_ptr threads_, 
+    SessionHandlerFactory& factory_,
+    int rfd,
+    int wfd,
+    bool isTrace_
+) :
+    readFd(rfd),
+    writeFd(wfd ? wfd : rfd),
+    readCallback(boost::bind(&EventChannelConnection::closeOnException,
+                             this, &EventChannelConnection::endInitRead)),
+
+    isWriting(false),
+    isClosed(false),
+    threads(threads_),
+    handler(factory_.create(this)),
+    in(bufferSize),
+    out(bufferSize),
+    isTrace(isTrace_)
+{
+    BOOST_ASSERT(readFd > 0);
+    BOOST_ASSERT(writeFd > 0);
+    closeOnException(&EventChannelConnection::startRead);
+}
+
+
+void EventChannelConnection::send(std::auto_ptr<AMQFrame> frame) {
+    {
+        Monitor::ScopedLock lock(monitor);
+        assert(frame.get());
+        writeFrames.push_back(frame.release());
+    }
+    closeOnException(&EventChannelConnection::startWrite);
+}
+
+void EventChannelConnection::close() {
+    {
+        Monitor::ScopedLock lock(monitor);
+        if (isClosed)
+            return;
+        isClosed = true;
+    }
+    ::close(readFd);
+    ::close(writeFd);
+    {
+        Monitor::ScopedLock lock(monitor);
+        while (busyThreads > 0)
+            monitor.wait();
+    }
+    handler->closed();
+}
+
+void EventChannelConnection::closeNoThrow() {
+    Exception::tryCatchLog<void>(
+        boost::bind(&EventChannelConnection::close, this),
+        false,
+        "Exception closing channel"
+    );
+}
+
+/**
+ * Call f in a try/catch block and close the connection if 
+ * an exception is thrown.
+ */
+void EventChannelConnection::closeOnException(MemberFnPtr f)
+{
+    try {
+        Exception::tryCatchLog<void>(
+            boost::bind(f, this),
+            "Closing connection due to exception"
+        );
+        return;
+    } catch (...) {
+        // Exception was already logged by tryCatchLog
+        closeNoThrow();
+    }
+}
+    
+// Post the write event.
+// Always called inside closeOnException.
+// Called by endWrite and send, but only one thread writes at a time.
+// 
+void EventChannelConnection::startWrite() {
+    FrameQueue::auto_type frame;
+    {
+        Monitor::ScopedLock lock(monitor);
+        // Stop if closed or a write event is already in progress.
+        if (isClosed || isWriting)
+            return;
+        if (writeFrames.empty()) {
+            isWriting = false;
+            return;
+        }
+        isWriting = true;
+        frame = writeFrames.pop_front();
+    }
+    // No need to lock here - only one thread can be writing at a time.
+    out.clear();
+    if (isTrace)
+        cout << "Send on socket " << writeFd << ": " << *frame << endl;
+    frame->encode(out);
+    out.flip();
+    writeEvent = WriteEvent(
+        writeFd, out.start(), out.available(),
+        boost::bind(&EventChannelConnection::closeOnException,
+                    this, &EventChannelConnection::endWrite));
+    threads->post(writeEvent);
+}
+
+// ScopedBusy ctor increments busyThreads.
+// dtor decrements and calls monitor.notifyAll if it reaches 0.
+// 
+struct EventChannelConnection::ScopedBusy : public AtomicCount::ScopedIncrement
+{
+    ScopedBusy(EventChannelConnection& ecc)
+        : AtomicCount::ScopedIncrement(
+            ecc.busyThreads, boost::bind(&Monitor::notifyAll, &ecc.monitor))
+    {}
+};
+
+// Write event completed.
+// Always called by a channel thread inside closeOnException.
+// 
+void EventChannelConnection::endWrite() {
+    ScopedBusy(*this);
+    {
+        Monitor::ScopedLock lock(monitor);
+        isWriting = false;
+        if (isClosed)
+            return;
+        writeEvent.throwIfException();
+    }
+    // Check if there's more in to write in the write queue.
+    startWrite();
+}
+    
+
+// Post the read event.
+// Always called inside closeOnException.
+// Called from ctor and end[Init]Read, so only one call at a time
+// is possible since we only post one read event at a time.
+// 
+void EventChannelConnection::startRead() {
+    // Non blocking read, as much as we can swallow.
+    readEvent = ReadEvent(
+        readFd, in.start(), in.available(), readCallback,true);
+    threads->post(readEvent);
+}
+
+// Completion of initial read, expect protocolInit.
+// Always called inside closeOnException in channel thread.
+// Only called by one thread at a time.
+void EventChannelConnection::endInitRead() {
+    ScopedBusy(*this);
+    if (!isClosed) {
+        readEvent.throwIfException();
+        in.move(readEvent.getBytesRead());
+        in.flip();
+        ProtocolInitiation protocolInit;
+        if(protocolInit.decode(in)){
+            handler->initiated(&protocolInit);
+            readCallback = boost::bind(
+                &EventChannelConnection::closeOnException,
+                this, &EventChannelConnection::endRead);
+        }
+        in.compact();
+        // Continue reading.
+        startRead();
+    }
+}
+    
+// Normal reads, expect a frame.
+// Always called inside closeOnException in channel thread.
+void EventChannelConnection::endRead() {
+    ScopedBusy(*this);
+    if (!isClosed) {
+        readEvent.throwIfException();
+        in.move(readEvent.getBytesRead());
+        in.flip();
+        AMQFrame frame;
+        while (frame.decode(in)) {
+            // TODO aconway 2006-11-30: received should take Frame&
+            if (isTrace)
+                cout << "Received on socket " << readFd
+                     << ": " << frame << endl;
+            handler->received(&frame); 
+        }
+        in.compact();
+        startRead();
+    }
+}
+
+}} // namespace qpid::sys