libev/ev_poll.c

/*
 * libev poll fd activity backend
 *
 * Copyright (c) 2007,2008 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 <poll.h>

void inline_size
pollidx_init (int *base, int count)
{
  /* consider using memset (.., -1, ...), which is pratically guarenteed
   * to work on all systems implementing poll */
  while (count--)
    *base++ = -1;
}

static void
poll_modify (EV_P_ int fd, int oev, int nev)
{
  int idx;

  if (oev == nev)
    return;

  array_needsize (int, pollidxs, pollidxmax, fd + 1, pollidx_init);

  idx = pollidxs [fd];

  if (idx < 0) /* need to allocate a new pollfd */
    {
      pollidxs [fd] = idx = pollcnt++;
      array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
      polls [idx].fd = fd;
    }

  assert (polls [idx].fd == fd);

  if (nev)
    polls [idx].events =
        (nev & EV_READ ? POLLIN : 0)
        | (nev & EV_WRITE ? POLLOUT : 0);
  else /* remove pollfd */
    {
      pollidxs [fd] = -1;

      if (expect_true (idx < --pollcnt))
        {
          polls [idx] = polls [pollcnt];
          pollidxs [polls [idx].fd] = idx;
        }
    }
}

static void
poll_poll (EV_P_ ev_tstamp timeout)
{
  struct pollfd *p;
  int res;
  
  EV_SUSPEND_CB;
  res = poll (polls, pollcnt, (int)ceil (timeout * 1000.));
  EV_RESUME_CB;

  if (expect_false (res < 0))
    {
      if (errno == EBADF)
        fd_ebadf (EV_A);
      else if (errno == ENOMEM && !syserr_cb)
        fd_enomem (EV_A);
      else if (errno != EINTR)
        ev_syserr ("(libev) poll");
    }
  else
    for (p = polls; res; ++p)
      if (expect_false (p->revents)) /* this expect is debatable */
        {
          --res;

          if (expect_false (p->revents & POLLNVAL))
            fd_kill (EV_A_ p->fd);
          else
            fd_event (
              EV_A_
              p->fd,
              (p->revents & (POLLOUT | POLLERR | POLLHUP) ? EV_WRITE : 0)
              | (p->revents & (POLLIN | POLLERR | POLLHUP) ? EV_READ : 0)
            );
        }
}

int inline_size
poll_init (EV_P_ int flags)
{
  backend_fudge  = 0.; /* posix says this is zero */
  backend_modify = poll_modify;
  backend_poll   = poll_poll;

  pollidxs = 0; pollidxmax = 0;
  polls    = 0; pollmax    = 0; pollcnt = 0;

  return EVBACKEND_POLL;
}

void inline_size
poll_destroy (EV_P)
{
  ev_free (pollidxs);
  ev_free (polls);
}

Revision:	1.29
Committed:	Fri Jul 10 00:36:21 2009 UTC (14 years, 10 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.28:	+2 -2 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	/*
2	root	1.17	* libev poll fd activity backend
3	root	1.1	*
4	root	1.25	* Copyright (c) 2007,2008 Marc Alexander Lehmann <libev@schmorp.de>
5	root	1.1	* All rights reserved.
6			*
7	root	1.21	* Redistribution and use in source and binary forms, with or without modifica-
8			* tion, are permitted provided that the following conditions are met:
9			*
10			* 1. Redistributions of source code must retain the above copyright notice,
11			* this list of conditions and the following disclaimer.
12			*
13			* 2. Redistributions in binary form must reproduce the above copyright
14			* notice, this list of conditions and the following disclaimer in the
15			* documentation and/or other materials provided with the distribution.
16			*
17			* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
18			* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
19			* CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
20			* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
21			* CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22			* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23			* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24			* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
25			* ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
26			* OF THE POSSIBILITY OF SUCH DAMAGE.
27	root	1.1	*
28	root	1.21	* Alternatively, the contents of this file may be used under the terms of
29			* the GNU General Public License ("GPL") version 2 or any later version,
30			* in which case the provisions of the GPL are applicable instead of
31			* the above. If you wish to allow the use of your version of this file
32			* only under the terms of the GPL and not to allow others to use your
33			* version of this file under the BSD license, indicate your decision
34			* by deleting the provisions above and replace them with the notice
35			* and other provisions required by the GPL. If you do not delete the
36			* provisions above, a recipient may use your version of this file under
37			* either the BSD or the GPL.
38	root	1.1	*/
39
40	root	1.2	#include <poll.h>
41	root	1.1
42	root	1.18	void inline_size
43	root	1.2	pollidx_init (int *base, int count)
44	root	1.1	{
45	root	1.26	/* consider using memset (.., -1, ...), which is pratically guarenteed
46			* to work on all systems implementing poll */
47	root	1.2	while (count--)
48			*base++ = -1;
49	root	1.1	}
50
51			static void
52	root	1.3	poll_modify (EV_P_ int fd, int oev, int nev)
53	root	1.1	{
54	root	1.2	int idx;
55	root	1.6
56			if (oev == nev)
57			return;
58
59	root	1.9	array_needsize (int, pollidxs, pollidxmax, fd + 1, pollidx_init);
60	root	1.1
61	root	1.2	idx = pollidxs [fd];
62
63			if (idx < 0) /* need to allocate a new pollfd */
64			{
65	root	1.10	pollidxs [fd] = idx = pollcnt++;
66	root	1.14	array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
67	root	1.2	polls [idx].fd = fd;
68			}
69	root	1.1
70	root	1.10	assert (polls [idx].fd == fd);
71
72	root	1.2	if (nev)
73			polls [idx].events =
74			(nev & EV_READ ? POLLIN : 0)
75			\| (nev & EV_WRITE ? POLLOUT : 0);
76			else /* remove pollfd */
77			{
78	root	1.10	pollidxs [fd] = -1;
79
80	root	1.18	if (expect_true (idx < --pollcnt))
81	root	1.2	{
82			polls [idx] = polls [pollcnt];
83			pollidxs [polls [idx].fd] = idx;
84			}
85			}
86	root	1.1	}
87
88			static void
89	root	1.3	poll_poll (EV_P_ ev_tstamp timeout)
90	root	1.1	{
91	root	1.23	struct pollfd *p;
92	root	1.28	int res;
93
94	root	1.29	EV_SUSPEND_CB;
95	root	1.28	res = poll (polls, pollcnt, (int)ceil (timeout * 1000.));
96	root	1.29	EV_RESUME_CB;
97	root	1.1
98	root	1.18	if (expect_false (res < 0))
99	root	1.1	{
100	root	1.2	if (errno == EBADF)
101	root	1.3	fd_ebadf (EV_A);
102	root	1.7	else if (errno == ENOMEM && !syserr_cb)
103	root	1.3	fd_enomem (EV_A);
104	root	1.7	else if (errno != EINTR)
105	root	1.27	ev_syserr ("(libev) poll");
106	root	1.1	}
107	root	1.24	else
108			for (p = polls; res; ++p)
109			if (expect_false (p->revents)) /* this expect is debatable */
110			{
111			--res;
112
113			if (expect_false (p->revents & POLLNVAL))
114			fd_kill (EV_A_ p->fd);
115			else
116			fd_event (
117			EV_A_
118			p->fd,
119			(p->revents & (POLLOUT \| POLLERR \| POLLHUP) ? EV_WRITE : 0)
120			\| (p->revents & (POLLIN \| POLLERR \| POLLHUP) ? EV_READ : 0)
121			);
122			}
123	root	1.1	}
124
125	root	1.17	int inline_size
126	root	1.3	poll_init (EV_P_ int flags)
127	root	1.1	{
128	root	1.20	backend_fudge = 0.; /* posix says this is zero */
129	root	1.16	backend_modify = poll_modify;
130			backend_poll = poll_poll;
131	root	1.3
132	root	1.4	pollidxs = 0; pollidxmax = 0;
133	root	1.5	polls = 0; pollmax = 0; pollcnt = 0;
134	root	1.4
135	root	1.15	return EVBACKEND_POLL;
136	root	1.1	}
137	root	1.4
138	root	1.17	void inline_size
139	root	1.4	poll_destroy (EV_P)
140			{
141	root	1.7	ev_free (pollidxs);
142			ev_free (polls);
143	root	1.4	}
144	root	1.9