summaryrefslogtreecommitdiffstats
path: root/contrib/libev/ev_poll.c
blob: e5508ddb0c25ec968f9a600dca52b000968fea53 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/*
 * libev poll fd activity backend
 *
 * Copyright (c) 2007,2008,2009,2010,2011,2016,2019 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>

inline_size
void
array_needsize_pollidx (int *base, int offset, int count)
{
  /* using memset (.., -1, ...) is tempting, we we try
   * to be ultraportable
   */
  base += offset;
  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, array_needsize_pollidx);

  idx = pollidxs [fd];

  if (idx < 0) /* need to allocate a new pollfd */
    {
      pollidxs [fd] = idx = pollcnt++;
      array_needsize (struct pollfd, polls, pollmax, pollcnt, array_needsize_noinit);
      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 (ecb_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_RELEASE_CB;
  res = poll (polls, pollcnt, EV_TS_TO_MSEC (timeout));
  EV_ACQUIRE_CB;

  if (ecb_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)
      {
        assert (("libev: poll returned illegal result, broken BSD kernel?", p < polls + pollcnt));

        if (ecb_expect_false (p->revents)) /* this expect is debatable */
          {
            --res;

            if (ecb_expect_false (p->revents & POLLNVAL))
              {
                assert (("libev: poll found invalid fd in poll set", 0));
                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)
              );
          }
      }
}

inline_size
int
poll_init (EV_P_ int flags)
{
  backend_mintime = EV_TS_CONST (1e-3);
  backend_modify  = poll_modify;
  backend_poll    = poll_poll;

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

  return EVBACKEND_POLL;
}

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