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 = poll (polls, pollcnt, (int)ceil (timeout * 1000.));

  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)
        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:	1.26
Committed:	Thu Oct 23 04:56:49 2008 UTC (15 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.25:	+2 -0 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* libev poll fd activity backend
3	*
4	* Copyright (c) 2007,2008 Marc Alexander Lehmann <libev@schmorp.de>
5	* All rights reserved.
6	*
7	* 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	*
28	* 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	*/
39
40	#include <poll.h>
41
42	void inline_size
43	pollidx_init (int *base, int count)
44	{
45	/* consider using memset (.., -1, ...), which is pratically guarenteed
46	* to work on all systems implementing poll */
47	while (count--)
48	*base++ = -1;
49	}
50
51	static void
52	poll_modify (EV_P_ int fd, int oev, int nev)
53	{
54	int idx;
55
56	if (oev == nev)
57	return;
58
59	array_needsize (int, pollidxs, pollidxmax, fd + 1, pollidx_init);
60
61	idx = pollidxs [fd];
62
63	if (idx < 0) /* need to allocate a new pollfd */
64	{
65	pollidxs [fd] = idx = pollcnt++;
66	array_needsize (struct pollfd, polls, pollmax, pollcnt, EMPTY2);
67	polls [idx].fd = fd;
68	}
69
70	assert (polls [idx].fd == fd);
71
72	if (nev)
73	polls [idx].events =
74	(nev & EV_READ ? POLLIN : 0)
75	\| (nev & EV_WRITE ? POLLOUT : 0);
76	else /* remove pollfd */
77	{
78	pollidxs [fd] = -1;
79
80	if (expect_true (idx < --pollcnt))
81	{
82	polls [idx] = polls [pollcnt];
83	pollidxs [polls [idx].fd] = idx;
84	}
85	}
86	}
87
88	static void
89	poll_poll (EV_P_ ev_tstamp timeout)
90	{
91	struct pollfd *p;
92	int res = poll (polls, pollcnt, (int)ceil (timeout * 1000.));
93
94	if (expect_false (res < 0))
95	{
96	if (errno == EBADF)
97	fd_ebadf (EV_A);
98	else if (errno == ENOMEM && !syserr_cb)
99	fd_enomem (EV_A);
100	else if (errno != EINTR)
101	syserr ("(libev) poll");
102	}
103	else
104	for (p = polls; res; ++p)
105	if (expect_false (p->revents)) /* this expect is debatable */
106	{
107	--res;
108
109	if (expect_false (p->revents & POLLNVAL))
110	fd_kill (EV_A_ p->fd);
111	else
112	fd_event (
113	EV_A_
114	p->fd,
115	(p->revents & (POLLOUT \| POLLERR \| POLLHUP) ? EV_WRITE : 0)
116	\| (p->revents & (POLLIN \| POLLERR \| POLLHUP) ? EV_READ : 0)
117	);
118	}
119	}
120
121	int inline_size
122	poll_init (EV_P_ int flags)
123	{
124	backend_fudge = 0.; /* posix says this is zero */
125	backend_modify = poll_modify;
126	backend_poll = poll_poll;
127
128	pollidxs = 0; pollidxmax = 0;
129	polls = 0; pollmax = 0; pollcnt = 0;
130
131	return EVBACKEND_POLL;
132	}
133
134	void inline_size
135	poll_destroy (EV_P)
136	{
137	ev_free (pollidxs);
138	ev_free (polls);
139	}
140