CSE2410 Fall 2014 Bounce

/*

 * libevent compatibility layer

 *

 * Copyright (c) 2007,2008,2009 Marc Alexander Lehmann <libev@schmorp.de>

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without modifica-

 * tion, are permitted provided that the following conditions are met:

 * 

 *   1.  Redistributions of source code must retain the above copyright notice,

 *       this list of conditions and the following disclaimer.

 * 

 *   2.  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.

 * 

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED

 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-

 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO

 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-

 * CIAL, 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 OTH-

 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 *

 * Alternatively, the contents of this file may be used under the terms of

 * the GNU General Public License ("GPL") version 2 or any later version,

 * in which case the provisions of the GPL are applicable instead of

 * the above. If you wish to allow the use of your version of this file

 * only under the terms of the GPL and not to allow others to use your

 * version of this file under the BSD license, indicate your decision

 * by deleting the provisions above and replace them with the notice

 * and other provisions required by the GPL. If you do not delete the

 * provisions above, a recipient may use your version of this file under

 * either the BSD or the GPL.

 */

#include <stddef.h>

#include <stdlib.h>

#include <assert.h>

#ifdef EV_EVENT_H

# include EV_EVENT_H

#else

# include "event.h"

#endif

#if EV_MULTIPLICITY

# define dLOOPev struct ev_loop *loop = (struct ev_loop *)ev->ev_base

# define dLOOPbase struct ev_loop *loop = (struct ev_loop *)base

#else

# define dLOOPev

# define dLOOPbase

#endif

/* never accessed, will always be cast from/to ev_loop */

struct event_base

{

  int dummy;

};

static struct event_base *ev_x_cur;

static void

ev_tv_set (struct timeval *tv, ev_tstamp at)

{

  tv->tv_sec  = (long)at;

  tv->tv_usec = (long)((at - (ev_tstamp)tv->tv_sec) * 1e6);

}

static ev_tstamp

ev_tv_get (struct timeval *tv)

{

  if (tv)

    return tv->tv_sec + tv->tv_usec * 1e-6;

  else

    return -1.;

}

#define EVENT_STRINGIFY(s) # s

#define EVENT_VERSION(a,b) EVENT_STRINGIFY (a) "." EVENT_STRINGIFY (b)

const char *event_get_version (void)

{

  /* returns ABI, not API or library, version */

  return EVENT_VERSION (EV_VERSION_MAJOR, EV_VERSION_MINOR);

}

const char *event_get_method (void)

{

  return "libev";

}

void *event_init (void)

{

#if EV_MULTIPLICITY

  if (ev_x_cur)

    ev_x_cur = (struct event_base *)ev_loop_new (EVFLAG_AUTO);

  else

    ev_x_cur = (struct event_base *)ev_default_loop (EVFLAG_AUTO);

#else

  assert (("libev: multiple event bases not supported when not compiled with EV_MULTIPLICITY", !ev_x_cur));

  ev_x_cur = (struct event_base *)(long)ev_default_loop (EVFLAG_AUTO);

#endif

  return ev_x_cur;

}

void event_base_free (struct event_base *base)

{

  dLOOPbase;

#if EV_MULTIPLICITY

  if (ev_default_loop (EVFLAG_AUTO) != loop)

    ev_loop_destroy (loop);

#endif

}

int event_dispatch (void)

{

  return event_base_dispatch (ev_x_cur);

}

#ifdef EV_STANDALONE

void event_set_log_callback (event_log_cb cb)

{

  /* nop */

}

#endif

int event_loop (int flags)

{

  return event_base_loop (ev_x_cur, flags);

}

int event_loopexit (struct timeval *tv)

{

  return event_base_loopexit (ev_x_cur, tv);

}

static void

ev_x_cb (struct event *ev, int revents)

{

  revents &= EV_READ | EV_WRITE | EV_TIMEOUT | EV_SIGNAL;

  ev->ev_res = revents;

  ev->ev_callback (ev->ev_fd, (short)revents, ev->ev_arg);

}

static void

ev_x_cb_sig (EV_P_ struct ev_signal *w, int revents)

{

  struct event *ev = (struct event *)(((char *)w) - offsetof (struct event, iosig.sig));

  if (revents & EV_ERROR)

    event_del (ev);

  ev_x_cb (ev, revents);

}

static void

ev_x_cb_io (EV_P_ struct ev_io *w, int revents)

{

  struct event *ev = (struct event *)(((char *)w) - offsetof (struct event, iosig.io));

  if ((revents & EV_ERROR) || !(ev->ev_events & EV_PERSIST))

    event_del (ev);

  ev_x_cb (ev, revents);

}

static void

ev_x_cb_to (EV_P_ struct ev_timer *w, int revents)

{

  struct event *ev = (struct event *)(((char *)w) - offsetof (struct event, to));

  event_del (ev);

  ev_x_cb (ev, revents);

}

void event_set (struct event *ev, int fd, short events, void (*cb)(int, short, void *), void *arg)

{

  if (events & EV_SIGNAL)

    ev_init (&ev->iosig.sig, ev_x_cb_sig);

  else

    ev_init (&ev->iosig.io, ev_x_cb_io);

  ev_init (&ev->to, ev_x_cb_to);

  ev->ev_base     = ev_x_cur; /* not threadsafe, but it's how libevent works */

  ev->ev_fd       = fd;

  ev->ev_events   = events;

  ev->ev_pri      = 0;

  ev->ev_callback = cb;

  ev->ev_arg      = arg;

  ev->ev_res      = 0;

  ev->ev_flags    = EVLIST_INIT;

}

int event_once (int fd, short events, void (*cb)(int, short, void *), void *arg, struct timeval *tv)

{

  return event_base_once (ev_x_cur, fd, events, cb, arg, tv);

}

int event_add (struct event *ev, struct timeval *tv)

{

  dLOOPev;

  if (ev->ev_events & EV_SIGNAL)

    {

      if (!ev_is_active (&ev->iosig.sig))

        {

          ev_signal_set (&ev->iosig.sig, ev->ev_fd);

          ev_signal_start (EV_A_ &ev->iosig.sig);

          ev->ev_flags |= EVLIST_SIGNAL;

        }

    }

  else if (ev->ev_events & (EV_READ | EV_WRITE))

    {

      if (!ev_is_active (&ev->iosig.io))

        {

          ev_io_set (&ev->iosig.io, ev->ev_fd, ev->ev_events & (EV_READ | EV_WRITE));

          ev_io_start (EV_A_ &ev->iosig.io);

          ev->ev_flags |= EVLIST_INSERTED;

        }

    }

  if (tv)

    {

      ev->to.repeat = ev_tv_get (tv);

      ev_timer_again (EV_A_ &ev->to);

      ev->ev_flags |= EVLIST_TIMEOUT;

    }

  else

    {

      ev_timer_stop (EV_A_ &ev->to);

      ev->ev_flags &= ~EVLIST_TIMEOUT;

    }

  ev->ev_flags |= EVLIST_ACTIVE;

  return 0;

}

int event_del (struct event *ev)

{

  dLOOPev;

  if (ev->ev_events & EV_SIGNAL)

    ev_signal_stop (EV_A_ &ev->iosig.sig);

  else if (ev->ev_events & (EV_READ | EV_WRITE))

    ev_io_stop (EV_A_ &ev->iosig.io);

  if (ev_is_active (&ev->to))

    ev_timer_stop (EV_A_ &ev->to);

  ev->ev_flags = EVLIST_INIT;

  return 0;

}

void event_active (struct event *ev, int res, short ncalls)

{

  dLOOPev;

  if (res & EV_TIMEOUT)

    ev_feed_event (EV_A_ &ev->to, res & EV_TIMEOUT);

  if (res & EV_SIGNAL)

    ev_feed_event (EV_A_ &ev->iosig.sig, res & EV_SIGNAL);

  if (res & (EV_READ | EV_WRITE))

    ev_feed_event (EV_A_ &ev->iosig.io, res & (EV_READ | EV_WRITE));

}

int event_pending (struct event *ev, short events, struct timeval *tv)

{

  short revents = 0;

  dLOOPev;

  if (ev->ev_events & EV_SIGNAL)

    {

      /* sig */

      if (ev_is_active (&ev->iosig.sig) || ev_is_pending (&ev->iosig.sig))

        revents |= EV_SIGNAL;

    }

  else if (ev->ev_events & (EV_READ | EV_WRITE))

    {

      /* io */

      if (ev_is_active (&ev->iosig.io) || ev_is_pending (&ev->iosig.io))

        revents |= ev->ev_events & (EV_READ | EV_WRITE);

    }

  if (ev->ev_events & EV_TIMEOUT || ev_is_active (&ev->to) || ev_is_pending (&ev->to))

    {

      revents |= EV_TIMEOUT;

      if (tv)

        ev_tv_set (tv, ev_now (EV_A)); /* not sure if this is right :) */

    }

  return events & revents;

}

int event_priority_init (int npri)

{

  return event_base_priority_init (ev_x_cur, npri);

}

int event_priority_set (struct event *ev, int pri)

{

  ev->ev_pri = pri;

  return 0;

}

int event_base_set (struct event_base *base, struct event *ev)

{

  ev->ev_base = base;

  return 0;

}

int event_base_loop (struct event_base *base, int flags)

{

  dLOOPbase;

  ev_loop (EV_A_ flags);

  return 0;

}

int event_base_dispatch (struct event_base *base)

{

  return event_base_loop (base, 0);

}

static void

ev_x_loopexit_cb (int revents, void *base)

{

  dLOOPbase;

  ev_unloop (EV_A_ EVUNLOOP_ONE);

}

int event_base_loopexit (struct event_base *base, struct timeval *tv)

{

  ev_tstamp after = ev_tv_get (tv);

  dLOOPbase;

  ev_once (EV_A_ -1, 0, after >= 0. ? after : 0., ev_x_loopexit_cb, (void *)base);

  return 0;

}

struct ev_x_once

{

  int fd;

  void (*cb)(int, short, void *);

  void *arg;

};

static void

ev_x_once_cb (int revents, void *arg)

{

  struct ev_x_once *once = (struct ev_x_once *)arg;

  once->cb (once->fd, (short)revents, once->arg);

  free (once);

}

int event_base_once (struct event_base *base, int fd, short events, void (*cb)(int, short, void *), void *arg, struct timeval *tv)

{

  struct ev_x_once *once = (struct ev_x_once *)malloc (sizeof (struct ev_x_once));

  dLOOPbase;

  if (!once)

    return -1;

  once->fd  = fd;

  once->cb  = cb;

  once->arg = arg;

  ev_once (EV_A_ fd, events & (EV_READ | EV_WRITE), ev_tv_get (tv), ev_x_once_cb, (void *)once);

  return 0;

}

int event_base_priority_init (struct event_base *base, int npri)

{

  /*dLOOPbase;*/

  return 0;

}