libcore/include/sirikata/core/network/IOStrand.hpp

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/*  Sirikata Network Utilities
 *  IOStrand.hpp
 *
 *  Copyright (c) 2009, Ewen Cheslack-Postava
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are
 *  met:
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name of Sirikata nor the names of its contributors may
 *    be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef _SIRIKATA_IOSTRAND_HPP_
#define _SIRIKATA_IOSTRAND_HPP_

#include <sirikata/core/util/Platform.hpp>
#include <sirikata/core/network/IODefs.hpp>
#include <sirikata/core/util/AtomicTypes.hpp>
#include <sirikata/core/util/Noncopyable.hpp>
#include <sirikata/core/trace/WindowedStats.hpp>
#include <sirikata/core/task/Time.hpp>
#include <boost/thread.hpp>

namespace Sirikata {
namespace Network {

class SIRIKATA_EXPORT IOStrand : public Noncopyable {
  public:
    typedef std::tr1::unordered_map<const char*, uint32> TagCountMap;

  private:
    IOService& mService;
    InternalIOStrand* mImpl;
    const String mName;

#ifdef SIRIKATA_TRACK_EVENT_QUEUES
    // Track all strands that have been allocated. This needs to be
    // thread safe.
    typedef boost::mutex Mutex;
    typedef boost::lock_guard<Mutex> LockGuard;
    Mutex mMutex;

    AtomicValue<uint32> mTimersEnqueued;
    AtomicValue<uint32> mEnqueued;

    // Tracks the latency of recent handlers through the queue
    Trace::WindowedStats<Duration> mWindowedTimerLatencyStats;
    Trace::WindowedStats<Duration> mWindowedHandlerLatencyStats;

    // Track tags that trigger events
    TagCountMap mTagCounts;
#endif

    friend class IOService;

    IOStrand(IOService& io, const String& name);

#ifdef SIRIKATA_TRACK_EVENT_QUEUES
    void decrementTimerCount(const Time& start, const Duration& timer_duration, const IOCallback& cb, const char* tag);
    void decrementCount(const Time& start, const IOCallback& cb, const char* tag);
#endif

  protected:

    friend class StrandTCPSocket;

  public:

    template<typename CallbackType>
    class WrappedHandler;

    ~IOStrand();

    const String& name() const { return mName; }

    IOService& service() const;

    void dispatch(const IOCallback& handler, const char* tag = NULL);

    void post(const IOCallback& handler, const char* tag = NULL);
    void post(const Duration& waitFor, const IOCallback& handler, const char* tag = NULL);

    IOCallback wrap(const IOCallback& handler);


    template<typename CallbackType>
    WrappedHandler<CallbackType> wrap(const CallbackType& handler);



#ifdef SIRIKATA_TRACK_EVENT_QUEUES
    uint32 numTimersEnqueued() const { return mTimersEnqueued.read(); }
    uint32 numEnqueued() const { return mEnqueued.read(); }

    Duration timerLatency() const { return mWindowedTimerLatencyStats.average(); }
    Duration handlerLatency() const { return mWindowedHandlerLatencyStats.average(); }

    TagCountMap enqueuedTags() const;
#endif

};

typedef std::tr1::shared_ptr<IOStrand> IOStrandPtr;

} // namespace Network
} // namespace Sirikata

#endif //_SIRIKATA_IOSERVICE_HPP_