summaryrefslogtreecommitdiff
path: root/src/pulsecore/poll-posix.c
blob: e2322951c12af442750e057d35d6c910426a19d5 (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
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235

/***
  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, see <http://www.gnu.org/licenses/>.
***/

/***
   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

#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif

#include <errno.h>
#include <fcntl.h>

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

#include <pulsecore/socket.h>
#include <pulsecore/core-util.h>
#include <pulse/util.h>

#include "poll.h"

/* Mac OSX fails to implement poll() in a working way since 10.4. IOW, for
 * several years. We need to enable a dirty workaround and emulate that call
 * with select(), just like for Windows. sic! */

#if !defined(HAVE_POLL_H) || defined(OS_IS_DARWIN)

int pa_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;
#ifdef OS_IS_WIN32
    char data[64];
#endif

    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(maxfd + 1, &rset, &wset, &xset, (timeout == -1 ? NULL : &tv));

    if ((ready == -1) && (errno == EBADF)) {
        ready = 0;
        maxfd = -1;

#ifdef OS_IS_WIN32
        /*
         * Windows has no fcntl(), so we have to trick around with more
         * select() calls to find out what went wrong
         */

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

        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(f->fd, &rset, &wset, &xset, &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;
                }
            }
        }

#else /* !OS_IS_WIN32 */

        for (f = fds; f < &fds[nfds]; f++)
            if (f->fd != -1) {
                /* use fcntl() to find out whether the descriptor is valid */
                if (fcntl(f->fd, F_GETFL) != -1) {
                    if (f->fd > maxfd && (f->events & (POLLIN|POLLOUT|POLLPRI))) {
                        maxfd = f->fd;
                        ready++;
                    }
                } else {
                    FD_CLR(f->fd, &rset);
                    FD_CLR(f->fd, &wset);
                    FD_CLR(f->fd, &xset);
                }
            }

#endif

        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(maxfd + 1, &rset, &wset, &xset, (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! */
#ifdef OS_IS_DARWIN
                    /* There is a bug in Mac OS X that causes it to ignore MSG_PEEK
                     * for some kinds of descriptors.  Detect if this descriptor is a
                     * connected socket, a server socket, or something else using a
                     * 0-byte recv, and use ioctl(2) to detect POLLHUP.  */
                    int r = recv(f->fd, NULL, 0, MSG_PEEK);
                    if (r == 0 || (r < 0 && errno == ENOTSOCK))
                        ioctl(f->fd, FIONREAD, &r);

                    if (r == 0)
                        f->revents |= POLLHUP;
#else /* !OS_IS_DARWIN */
                    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;
                        }
                    }
#endif

                    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 */