Adding files for EventChannel implementation.

git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@489110 13f79535-47bb-0310-9956-ffa450edef68

3 files changed, 480 insertions, 0 deletions

diff --git a/cpp/lib/common/sys/posix/EventChannelAcceptor.cpp b/cpp/lib/common/sys/posix/EventChannelAcceptor.cpp
new file mode 100644
index 0000000000..7cd6f60902
--- /dev/null
+++ b/cpp/lib/common/sys/posix/EventChannelAcceptor.cpp
@@ -0,0 +1,149 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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/assert.hpp>
+#include <boost/ptr_container/ptr_vector.hpp>
+#include <boost/ptr_container/ptr_deque.hpp>
+#include <boost/bind.hpp>
+#include <boost/scoped_ptr.hpp>
+
+#include <sys/SessionContext.h>
+#include <sys/SessionHandler.h>
+#include <sys/SessionHandlerFactory.h>
+#include <sys/Acceptor.h>
+#include <sys/Socket.h>
+#include <framing/Buffer.h>
+#include <framing/AMQFrame.h>
+#include <Exception.h>
+
+#include "EventChannelConnection.h"
+
+namespace qpid {
+namespace sys {
+
+using namespace qpid::framing;
+using namespace std;
+
+class EventChannelAcceptor : public Acceptor {
+  public:
+
+
+    EventChannelAcceptor(
+        int16_t port_, int backlog, int nThreads, bool trace_
+    );
+        
+    int getPort() const;
+    
+    void run(SessionHandlerFactory& factory);
+
+    void shutdown();
+
+  private:
+
+    void accept();
+
+    Mutex lock;
+    Socket listener;
+    const int port;
+    const bool isTrace;
+    bool isRunning;
+    boost::ptr_vector<EventChannelConnection> connections;
+    AcceptEvent acceptEvent;
+    SessionHandlerFactory* factory;
+    bool isShutdown;
+    EventChannelThreads::shared_ptr threads;
+};
+
+Acceptor::shared_ptr Acceptor::create(
+    int16_t port, int backlog, int threads, bool trace)
+{
+    return Acceptor::shared_ptr(
+        new EventChannelAcceptor(port, backlog, threads, trace));
+}
+
+// Must define Acceptor virtual dtor.
+Acceptor::~Acceptor() {}
+
+EventChannelAcceptor::EventChannelAcceptor(
+    int16_t port_, int backlog, int nThreads, bool trace_
+) : listener(Socket::createTcp()),
+    port(listener.listen(int(port_), backlog)),
+    isTrace(trace_),
+    isRunning(false),
+    acceptEvent(listener.fd(),
+                boost::bind(&EventChannelAcceptor::accept, this)),
+    factory(0),
+    isShutdown(false),
+    threads(EventChannelThreads::create(EventChannel::create(), nThreads))
+{ }
+    
+int EventChannelAcceptor::getPort() const {
+    return port;                // Immutable no need for lock.
+}
+    
+void EventChannelAcceptor::run(SessionHandlerFactory& f) {
+    {
+        Mutex::ScopedLock l(lock);
+        if (!isRunning && !isShutdown) {
+            isRunning = true;
+            factory = &f;
+            threads->post(acceptEvent);
+        }
+    }
+    threads->join();            // Wait for shutdown.
+}
+
+void EventChannelAcceptor::shutdown() {
+    bool doShutdown = false;
+    {
+        Mutex::ScopedLock l(lock);
+        doShutdown = !isShutdown; // I'm the shutdown thread.
+        isShutdown = true;
+    }
+    if (doShutdown) {
+        ::close(acceptEvent.getDescriptor());
+        threads->shutdown();
+        for_each(connections.begin(), connections.end(),
+                 boost::bind(&EventChannelConnection::close, _1));
+    }
+    threads->join();
+}
+
+void EventChannelAcceptor::accept()
+{
+    // No lock, we only post one accept event at a time.
+    if (isShutdown)
+        return;
+    if (acceptEvent.getException()) {
+        Exception::log(*acceptEvent.getException(),
+                       "EventChannelAcceptor::accept");
+        shutdown();
+        return;
+    }
+    // TODO aconway 2006-11-29: Need to reap closed connections also.
+    int fd = acceptEvent.getAcceptedDesscriptor();
+    connections.push_back(
+        new EventChannelConnection(threads, *factory, fd, fd, isTrace));
+    threads->post(acceptEvent); // Keep accepting.
+}
+
+}} // namespace qpid::sys
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
diff --git a/cpp/lib/common/sys/posix/EventChannelConnection.h b/cpp/lib/common/sys/posix/EventChannelConnection.h
new file mode 100644
index 0000000000..bace045993
--- /dev/null
+++ b/cpp/lib/common/sys/posix/EventChannelConnection.h
@@ -0,0 +1,102 @@
+#ifndef _posix_EventChannelConnection_h
+#define _posix_EventChannelConnection_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 <boost/ptr_container/ptr_deque.hpp>
+
+#include "EventChannelThreads.h"
+#include "sys/Monitor.h"
+#include "sys/SessionContext.h"
+#include "sys/SessionHandler.h"
+#include "sys/AtomicCount.h"
+#include "framing/AMQFrame.h"
+
+namespace qpid {
+namespace sys {
+
+class SessionHandlerFactory;
+
+/**
+ * Implements SessionContext and delegates to a SessionHandler
+ * for a connection via the EventChannel.
+ *@param readDescriptor file descriptor for reading.
+ *@param writeDescriptor file descriptor for writing,
+ * by default same as readDescriptor
+ */
+class EventChannelConnection : public SessionContext {
+  public:
+    EventChannelConnection(
+        EventChannelThreads::shared_ptr threads, 
+        SessionHandlerFactory& factory,
+        int readDescriptor, 
+        int writeDescriptor = 0,
+        bool isTrace = false
+    );
+
+    // TODO aconway 2006-11-30: SessionContext::send should take auto_ptr
+    virtual void send(qpid::framing::AMQFrame* frame) {
+        send(std::auto_ptr<qpid::framing::AMQFrame>(frame));
+    }
+            
+    virtual void send(std::auto_ptr<qpid::framing::AMQFrame> frame);
+
+    virtual void close();
+
+  private:
+    typedef boost::ptr_deque<qpid::framing::AMQFrame> FrameQueue;
+    typedef void (EventChannelConnection::*MemberFnPtr)();
+    struct ScopedBusy;
+
+    void startWrite();
+    void endWrite();
+    void startRead();
+    void endInitRead();
+    void endRead();
+    void closeNoThrow();
+    void closeOnException(MemberFnPtr);
+    bool shouldContinue(bool& flag);
+
+    static const size_t bufferSize;
+
+    Monitor monitor;
+
+    int readFd, writeFd;
+    ReadEvent readEvent;
+    WriteEvent writeEvent;
+    Event::Callback readCallback;
+    bool isWriting;
+    bool isClosed;
+    AtomicCount busyThreads;
+
+    EventChannelThreads::shared_ptr threads;
+    std::auto_ptr<SessionHandler> handler;
+    qpid::framing::Buffer in, out;
+    FrameQueue writeFrames;
+    bool isTrace;
+    
+  friend struct ScopedBusy;
+};
+    
+
+}} // namespace qpid::sys
+
+
+
+#endif  /*!_posix_EventChannelConnection_h*/