summaryrefslogtreecommitdiffstats
path: root/src/pulsecore/poll.c
blob: 46a69c5f568ee2e84f10b445f8c18a68d4d6f41e (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
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194

/***
  This file is part of PulseAudio.

  Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB

  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2.1 of the License,
  or (at your option) any later version.

  PulseAudio is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with PulseAudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

/***
   Based on work for the GNU C Library.
   Copyright (C) 1994, 1996, 1997 Free Software Foundation, Inc.
***/

/* Poll the file descriptors described by the NFDS structures starting at
   FDS.  If TIMEOUT is nonzero and not -1, allow TIMEOUT milliseconds for
   an event to occur; if TIMEOUT is -1, block until an event occurs.
   Returns the number of file descriptors with events, zero if timed out,
   or -1 for errors.  */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <errno.h>

#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif

#include "winsock.h"

#ifndef HAVE_POLL_H

#include <pulsecore/core-util.h>

#include "poll.h"

int poll (struct pollfd *fds, unsigned long int nfds, int timeout) {
    struct timeval tv;
    fd_set rset, wset, xset;
    struct pollfd *f;
    int ready;
    int maxfd = 0;
    char data[64];

    FD_ZERO (&rset);
    FD_ZERO (&wset);
    FD_ZERO (&xset);

    if (nfds == 0) {
        if (timeout >= 0) {
            pa_msleep(timeout);
            return 0;
        }

#ifdef OS_IS_WIN32
        /*
         * Windows does not support signals properly so waiting for them would
         * mean a deadlock.
         */
        pa_msleep(100);
        return 0;
#else
        return select(0, NULL, NULL, NULL, NULL);
#endif
    }

    for (f = fds; f < &fds[nfds]; ++f) {
        if (f->fd != -1) {
            if (f->events & POLLIN)
                FD_SET (f->fd, &rset);
            if (f->events & POLLOUT)
                FD_SET (f->fd, &wset);
            if (f->events & POLLPRI)
                FD_SET (f->fd, &xset);
            if (f->fd > maxfd && (f->events & (POLLIN|POLLOUT|POLLPRI)))
                maxfd = f->fd;
        }
    }

    tv.tv_sec = timeout / 1000;
    tv.tv_usec = (timeout % 1000) * 1000;

    ready = select ((SELECT_TYPE_ARG1) maxfd + 1, SELECT_TYPE_ARG234 &rset,
                    SELECT_TYPE_ARG234 &wset, SELECT_TYPE_ARG234 &xset,
                    SELECT_TYPE_ARG5 (timeout == -1 ? NULL : &tv));
    if ((ready == -1) && (errno == EBADF)) {
        ready = 0;

        FD_ZERO (&rset);
        FD_ZERO (&wset);
        FD_ZERO (&xset);

        maxfd = -1;

        for (f = fds; f < &fds[nfds]; ++f) {
            if (f->fd != -1) {
                fd_set sngl_rset, sngl_wset, sngl_xset;

                FD_ZERO (&sngl_rset);
                FD_ZERO (&sngl_wset);
                FD_ZERO (&sngl_xset);

                if (f->events & POLLIN)
                    FD_SET (f->fd, &sngl_rset);
                if (f->events & POLLOUT)
                    FD_SET (f->fd, &sngl_wset);
                if (f->events & POLLPRI)
                    FD_SET (f->fd, &sngl_xset);
                if (f->events & (POLLIN|POLLOUT|POLLPRI)) {
                    struct timeval singl_tv;

                    singl_tv.tv_sec = 0;
                    singl_tv.tv_usec = 0;

                    if (select((SELECT_TYPE_ARG1) f->fd, SELECT_TYPE_ARG234 &rset,
                               SELECT_TYPE_ARG234 &wset, SELECT_TYPE_ARG234 &xset,
                               SELECT_TYPE_ARG5 &singl_tv) != -1) {
                        if (f->events & POLLIN)
                            FD_SET (f->fd, &rset);
                        if (f->events & POLLOUT)
                            FD_SET (f->fd, &wset);
                        if (f->events & POLLPRI)
                            FD_SET (f->fd, &xset);
                        if (f->fd > maxfd && (f->events & (POLLIN|POLLOUT|POLLPRI)))
                            maxfd = f->fd;
                        ++ready;
                    } else if (errno == EBADF)
                        f->revents |= POLLNVAL;
                }
            }
        }

        if (ready) {
        /* Linux alters the tv struct... but it shouldn't matter here ...
         * as we're going to be a little bit out anyway as we've just eaten
         * more than a couple of cpu cycles above */
            ready = select ((SELECT_TYPE_ARG1) maxfd + 1, SELECT_TYPE_ARG234 &rset,
                            SELECT_TYPE_ARG234 &wset, SELECT_TYPE_ARG234 &xset,
                            SELECT_TYPE_ARG5 (timeout == -1 ? NULL : &tv));
        }
    }

#ifdef OS_IS_WIN32
    errno = WSAGetLastError();
#endif

    if (ready > 0) {
        ready = 0;
        for (f = fds; f < &fds[nfds]; ++f) {
            f->revents = 0;
            if (f->fd != -1) {
                if (FD_ISSET (f->fd, &rset)) {
                    /* support for POLLHUP.  An hung up descriptor does not
                       increase the return value! */
                    if (recv (f->fd, data, 64, MSG_PEEK) == -1) {
                        if (errno == ESHUTDOWN || errno == ECONNRESET ||
                            errno == ECONNABORTED || errno == ENETRESET) {
                            fprintf(stderr, "Hangup\n");
                            f->revents |= POLLHUP;
                        }
                    }

                    if (f->revents == 0)
                        f->revents |= POLLIN;
                }
                if (FD_ISSET (f->fd, &wset))
                    f->revents |= POLLOUT;
                if (FD_ISSET (f->fd, &xset))
                    f->revents |= POLLPRI;
            }
            if (f->revents)
                ready++;
        }
    }

    return ready;
}

#endif /* HAVE_SYS_POLL_H */