soa/service/epoller.h

/* epoller.h                                                       -*- C++ -*-
   Jeremy Barnes, 26 September 2012
   Copyright (c) 2012 Datacratic.  All rights reserved.

   Structure do allow multiplexing of FDs based upon epoll.
*/

#ifndef __endpoint__epoller_h__
#define __endpoint__epoller_h__

#include <functional>
#include "soa/service/async_event_source.h"

struct epoll_event;

namespace Datacratic {

/*****************************************************************************/
/* EPOLLER                                                                   */
/*****************************************************************************/

struct Epoller: public AsyncEventSource {

    Epoller();

    ~Epoller();

    void init(int maxFds);

    void close();

    void addFd(int fd, void * data = 0);
    
    void addFdOneShot(int fd, void * data = 0);

    void restartFdOneShot(int fd, void * data = 0);

    void removeFd(int fd);
    
    typedef std::function<bool (epoll_event & event)> HandleEvent;
    typedef std::function<void ()> OnEvent;

    HandleEvent handleEvent;

    OnEvent beforeSleep;
    OnEvent afterSleep;

    int handleEvents(int usToWait = 0, int nEvents = 1,
                     const HandleEvent & handleEvent = HandleEvent(),
                     const OnEvent & beforeSleep = OnEvent(),
                     const OnEvent & afterSleep = OnEvent());

    virtual int selectFd() const
    {
        return epoll_fd;
    }

    virtual bool poll() const;

    virtual bool processOne()
    {
        handleEvents();
        return poll();
    }
    
private:
    /* Fd for the epoll mechanism. */
    int epoll_fd;
};

} // namespace Datacratic

#endif /* __endpoint__epoller_h__ */