/*

 * libev solaris event port backend

 *

 * Copyright (c) 2007,2008,2009,2010,2011 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.

 */

/* useful reading:

 *

 * http://bugs.opensolaris.org/view_bug.do?bug_id=6268715 (random results)

 * http://bugs.opensolaris.org/view_bug.do?bug_id=6455223 (just totally broken)

 * http://bugs.opensolaris.org/view_bug.do?bug_id=6873782 (manpage ETIME)

 * http://bugs.opensolaris.org/view_bug.do?bug_id=6874410 (implementation ETIME)

 * http://www.mail-archive.com/networking-discuss@opensolaris.org/msg11898.html ETIME vs. nget

 * http://src.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/lib/libc/port/gen/event_port.c (libc)

 * http://cvs.opensolaris.org/source/xref/onnv/onnv-gate/usr/src/uts/common/fs/portfs/port.c#1325 (kernel)

 */

#include <sys/types.h>

#include <sys/time.h>

#include <poll.h>

#include <port.h>

#include <string.h>

#include <errno.h>

inline_speed

void

port_associate_and_check (EV_P_ int fd, int ev)

{

  if (0 >

      port_associate (

         backend_fd, PORT_SOURCE_FD, fd,

         (ev & EV_READ ? POLLIN : 0)

         | (ev & EV_WRITE ? POLLOUT : 0),

         0

      )

  )

    {

      if (errno == EBADFD)

        fd_kill (EV_A_ fd);

      else

        ev_syserr ("(libev) port_associate");

    }

}

static void

port_modify (EV_P_ int fd, int oev, int nev)

{

  /* we need to reassociate no matter what, as closes are

   * once more silently being discarded.

   */

  if (!nev)

    {

      if (oev)

        port_dissociate (backend_fd, PORT_SOURCE_FD, fd);

    }

  else

    port_associate_and_check (EV_A_ fd, nev);

}

static void

port_poll (EV_P_ ev_tstamp timeout)

{

  int res, i;

  struct timespec ts;

  uint_t nget = 1;

  /* we initialise this to something we will skip in the loop, as */

  /* port_getn can return with nget unchanged, but no indication */

  /* whether it was the original value or has been updated :/ */

  port_events [0].portev_source = 0;

  EV_RELEASE_CB;

  EV_TS_SET (ts, timeout);

  res = port_getn (backend_fd, port_events, port_eventmax, &nget, &ts);

  EV_ACQUIRE_CB;

  /* port_getn may or may not set nget on error */

  /* so we rely on port_events [0].portev_source not being updated */

  if (res == -1 && errno != ETIME && errno != EINTR)

    ev_syserr ("(libev) port_getn (see http://bugs.opensolaris.org/view_bug.do?bug_id=6268715, try LIBEV_FLAGS=3 env variable)");

  for (i = 0; i < nget; ++i)

    {

      if (port_events [i].portev_source == PORT_SOURCE_FD)

        {

          int fd = port_events [i].portev_object;

          fd_event (

            EV_A_

            fd,

            (port_events [i].portev_events & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)

            | (port_events [i].portev_events & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)

          );

          fd_change (EV_A_ fd, EV__IOFDSET);

        }

    }

  if (expect_false (nget == port_eventmax))

    {

      ev_free (port_events);

      port_eventmax = array_nextsize (sizeof (port_event_t), port_eventmax, port_eventmax + 1);

      port_events = (port_event_t *)ev_malloc (sizeof (port_event_t) * port_eventmax);

    }

}

inline_size

int

port_init (EV_P_ int flags)

{

  /* Initialize the kernel queue */

  if ((backend_fd = port_create ()) < 0)

    return 0;

  assert (("libev: PORT_SOURCE_FD must not be zero", PORT_SOURCE_FD));

  fcntl (backend_fd, F_SETFD, FD_CLOEXEC); /* not sure if necessary, hopefully doesn't hurt */

  /* if my reading of the opensolaris kernel sources are correct, then

   * opensolaris does something very stupid: it checks if the time has already

   * elapsed and doesn't round up if that is the case,m otherwise it DOES round

   * up. Since we can't know what the case is, we need to guess by using a

   * "large enough" timeout. Normally, 1e-9 would be correct.

   */

  backend_mintime = 1e-3; /* needed to compensate for port_getn returning early */

  backend_modify  = port_modify;

  backend_poll    = port_poll;

  port_eventmax = 64; /* initial number of events receivable per poll */

  port_events = (port_event_t *)ev_malloc (sizeof (port_event_t) * port_eventmax);

  return EVBACKEND_PORT;

}

inline_size

void

port_destroy (EV_P)

{

  ev_free (port_events);

}

inline_size

void

port_fork (EV_P)

{

  close (backend_fd);

  while ((backend_fd = port_create ()) < 0)

    ev_syserr ("(libev) port");

  fcntl (backend_fd, F_SETFD, FD_CLOEXEC);

  /* re-register interest in fds */

  fd_rearm_all (EV_A);

}