1 files changed, 135 insertions, 0 deletions
diff --git a/qpid/cpp/src/qpid/sys/Poller.h b/qpid/cpp/src/qpid/sys/Poller.h
new file mode 100644
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+++ b/qpid/cpp/src/qpid/sys/Poller.h
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+#ifndef _sys_Poller_h
+#define _sys_Poller_h
+
+/*
+ *
+ * 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 "qpid/sys/Time.h"
+#include "qpid/sys/Runnable.h"
+#include "qpid/CommonImportExport.h"
+#include <boost/shared_ptr.hpp>
+
+namespace qpid {
+namespace sys {
+
+/**
+ * Poller is an abstract base class that registers callbacks to be
+ * called when there is IO activity. Concrete derived classes
+ * implement polling APIs such as epoll or equivalents on other
+ * operating systems.
+ *
+ * On the broker, Connection::received() is called with incoming
+ * frames from clients, and Connection::doOutput() is called when a
+ * connection is writeable.
+ *
+ * @see DispatchHandler for more details of normal use.
+ */
+class PollerHandle;
+class PollerPrivate;
+class Poller : public Runnable {
+    PollerPrivate* const impl;
+
+public:
+    typedef boost::shared_ptr<Poller> shared_ptr;
+
+    enum Direction {
+        NONE = 0,
+        INPUT,
+        OUTPUT,
+        INOUT
+    };
+
+    enum EventType {
+        INVALID = 0,
+        READABLE,
+        WRITABLE,
+        READ_WRITABLE,
+        DISCONNECTED,
+        SHUTDOWN,
+        TIMEOUT,
+        INTERRUPTED
+    };
+
+    struct Event {
+        PollerHandle* handle;
+        EventType type;
+        
+        Event(PollerHandle* handle0, EventType type0) :
+          handle(handle0),
+          type(type0) {
+        }
+        
+        void process();
+    };
+    
+    QPID_COMMON_EXTERN Poller();
+    QPID_COMMON_EXTERN ~Poller();
+    /** Note: this function is async-signal safe */
+    QPID_COMMON_EXTERN void shutdown();
+    
+    // Interrupt waiting for a specific poller handle
+    // returns true if we could interrupt the handle
+    // - in this case on return the handle is no longer being monitored,
+    //   but we will receive an event from some invocation of poller::wait
+    //   with the handle and the INTERRUPTED event type
+    // if it returns false then the handle is not being monitored by the poller
+    // - This can either be because it has just received an event which has been
+    //   reported and has not been reenabled since.
+    // - Because it was removed from the monitoring set
+    // - Or because it is already being interrupted 
+    QPID_COMMON_EXTERN bool interrupt(PollerHandle& handle);
+    
+    // Poller run loop
+    QPID_COMMON_EXTERN void run();
+
+    QPID_COMMON_EXTERN void registerHandle(PollerHandle& handle);
+    QPID_COMMON_EXTERN void unregisterHandle(PollerHandle& handle);
+    QPID_COMMON_EXTERN void monitorHandle(PollerHandle& handle, Direction dir);
+    QPID_COMMON_EXTERN void unmonitorHandle(PollerHandle& handle, Direction dir);
+    QPID_COMMON_EXTERN Event wait(Duration timeout = TIME_INFINITE);
+
+    QPID_COMMON_EXTERN bool hasShutdown();
+};
+
+/**
+ * Handle class to use for polling
+ */
+class IOHandle;
+class PollerHandlePrivate;
+class PollerHandle {
+    friend class Poller;
+    friend class PollerPrivate;
+    friend struct Poller::Event;
+
+    PollerHandlePrivate* const impl;
+    QPID_COMMON_INLINE_EXTERN virtual void processEvent(Poller::EventType) {};
+
+public:
+    QPID_COMMON_EXTERN PollerHandle(const IOHandle& h);
+    QPID_COMMON_EXTERN virtual ~PollerHandle();
+};
+
+inline void Poller::Event::process() {
+    handle->processEvent(type);
+}
+
+}}
+#endif // _sys_Poller_h