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#include "Reactor.hh"

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NetworkReactor::NetworkReactor (void) :

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    sockets()

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{

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}

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void NetworkReactor::poll (timeval *timeout) {

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    // start counting the maximum fd from -1, so that select is given nfds=0 if our list is empty

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    int fd_max = 0;

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    // zero our fdsets

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    fd_set read, write;

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    FD_ZERO(&read);

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    FD_ZERO(&write);

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    // inspect our sockets

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    for (std::list<NetworkSocket*>::iterator it = sockets.begin(); it != sockets.end(); it++) {

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        NetworkSocket *socket = *it;

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        // ask socket what events it wants

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        NetworkPollMask mask = socket->get_poll();

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        // set read/write

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        if (mask) {

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            // socket file descriptor...

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            int fd = socket->get_socket();

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            // ignore invalid FDs

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            if (fd < 0)

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                continue;

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            // update fd_max?

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            if (fd > fd_max)

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                fd_max = fd;

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            // read...

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            if (mask & POLL_READ)

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                FD_SET(socket->get_socket(), &read);

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            // write...

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            if (mask & POLL_WRITE)

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                FD_SET(socket->get_socket(), &write);

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        }

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    }

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    // run select

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    int ret;

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    // we never care about except

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    // pass NULL fdsets if they are empty

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    if ((ret = select(

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            fd_max + 1, 

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            fd_max ? &read : NULL, 

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            fd_max ? &write : NULL, 

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            NULL, 

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            timeout

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    )) < 0)

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        throw NetworkReactorError("select");

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    // ignore if we just timed out

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    if (ret == 0)

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        return;

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    // notify up to <ret> socket-events

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    for (std::list<NetworkSocket*>::iterator it = sockets.begin(); it != sockets.end() && ret > 0; it++) {

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        NetworkSocket *socket = *it;

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        // socket file descriptor...

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        int fd = socket->get_socket();

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        // ignore invalid FDs

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        if (fd < 0)

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            continue;

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        // mask of events detected

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        NetworkPollMask mask = 0;

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        // detect read

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        if (FD_ISSET(fd, &read)) {

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            mask |= POLL_READ;

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            ret--;

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        }

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        // detect write

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        if (FD_ISSET(fd, &write)) {

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            mask |= POLL_WRITE;

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            ret--;

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        }

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        // notify?

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        if (mask)

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            socket->notify(mask);

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    }

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}

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// the global reactor

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static NetworkReactor g_reactor;

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NetworkReactor *NetworkReactor::current = &g_reactor;

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