2 This file is part of PulseAudio.
4 Copyright 2006 Lennart Poettering
6 PulseAudio is free software; you can redistribute it and/or modify
7 it under the terms of the GNU Lesser General Public License as
8 published by the Free Software Foundation; either version 2.1 of the
9 License, or (at your option) any later version.
11 PulseAudio is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with PulseAudio; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
26 #ifdef HAVE_SYS_SYSCALL_H
27 #include <sys/syscall.h>
33 #include <pulsecore/atomic.h>
34 #include <pulsecore/log.h>
35 #include <pulsecore/thread.h>
36 #include <pulsecore/macro.h>
37 #include <pulsecore/core-util.h>
38 #include <pulse/xmalloc.h>
41 #include <pulsecore/pipe.h>
44 #ifdef HAVE_SYS_EVENTFD_H
45 #include <sys/eventfd.h>
52 #ifdef HAVE_SYS_EVENTFD_H
59 pa_fdsem
*pa_fdsem_new(void) {
62 f
= pa_xmalloc(PA_ALIGN(sizeof(pa_fdsem
)) + PA_ALIGN(sizeof(pa_fdsem_data
)));
64 #ifdef HAVE_SYS_EVENTFD_H
65 if ((f
->efd
= eventfd(0, 0)) >= 0) {
66 pa_make_fd_cloexec(f
->efd
);
67 f
->fds
[0] = f
->fds
[1] = -1;
71 if (pipe(f
->fds
) < 0) {
76 pa_make_fd_cloexec(f
->fds
[0]);
77 pa_make_fd_cloexec(f
->fds
[1]);
80 f
->data
= (pa_fdsem_data
*) ((uint8_t*) f
+ PA_ALIGN(sizeof(pa_fdsem
)));
82 pa_atomic_store(&f
->data
->waiting
, 0);
83 pa_atomic_store(&f
->data
->signalled
, 0);
84 pa_atomic_store(&f
->data
->in_pipe
, 0);
89 pa_fdsem
*pa_fdsem_open_shm(pa_fdsem_data
*data
, int event_fd
) {
93 pa_assert(event_fd
>= 0);
95 #ifdef HAVE_SYS_EVENTFD_H
96 f
= pa_xnew(pa_fdsem
, 1);
99 pa_make_fd_cloexec(f
->efd
);
100 f
->fds
[0] = f
->fds
[1] = -1;
107 pa_fdsem
*pa_fdsem_new_shm(pa_fdsem_data
*data
, int* event_fd
) {
113 #ifdef HAVE_SYS_EVENTFD_H
115 f
= pa_xnew(pa_fdsem
, 1);
117 if ((f
->efd
= eventfd(0, 0)) < 0) {
122 pa_make_fd_cloexec(f
->efd
);
123 f
->fds
[0] = f
->fds
[1] = -1;
126 pa_atomic_store(&f
->data
->waiting
, 0);
127 pa_atomic_store(&f
->data
->signalled
, 0);
128 pa_atomic_store(&f
->data
->in_pipe
, 0);
135 void pa_fdsem_free(pa_fdsem
*f
) {
138 #ifdef HAVE_SYS_EVENTFD_H
142 pa_close_pipe(f
->fds
);
147 static void flush(pa_fdsem
*f
) {
151 if (pa_atomic_load(&f
->data
->in_pipe
) <= 0)
157 #ifdef HAVE_SYS_EVENTFD_H
161 if ((r
= read(f
->efd
, &u
, sizeof(u
))) != sizeof(u
)) {
162 pa_assert(r
< 0 && errno
== EINTR
);
169 if ((r
= read(f
->fds
[0], &x
, sizeof(x
))) <= 0) {
170 pa_assert(r
< 0 && errno
== EINTR
);
174 } while (pa_atomic_sub(&f
->data
->in_pipe
, (int) r
) > (int) r
);
177 void pa_fdsem_post(pa_fdsem
*f
) {
180 if (pa_atomic_cmpxchg(&f
->data
->signalled
, 0, 1)) {
182 if (pa_atomic_load(&f
->data
->waiting
)) {
186 pa_atomic_inc(&f
->data
->in_pipe
);
190 #ifdef HAVE_SYS_EVENTFD_H
194 if ((r
= write(f
->efd
, &u
, sizeof(u
))) != sizeof(u
)) {
195 pa_assert(r
< 0 && errno
== EINTR
);
201 if ((r
= write(f
->fds
[1], &x
, 1)) != 1) {
202 pa_assert(r
< 0 && errno
== EINTR
);
212 void pa_fdsem_wait(pa_fdsem
*f
) {
217 if (pa_atomic_cmpxchg(&f
->data
->signalled
, 1, 0))
220 pa_atomic_inc(&f
->data
->waiting
);
222 while (!pa_atomic_cmpxchg(&f
->data
->signalled
, 1, 0)) {
226 #ifdef HAVE_SYS_EVENTFD_H
230 if ((r
= read(f
->efd
, &u
, sizeof(u
))) != sizeof(u
)) {
231 pa_assert(r
< 0 && errno
== EINTR
);
239 if ((r
= read(f
->fds
[0], &x
, sizeof(x
))) <= 0) {
240 pa_assert(r
< 0 && errno
== EINTR
);
244 pa_atomic_sub(&f
->data
->in_pipe
, (int) r
);
247 pa_assert_se(pa_atomic_dec(&f
->data
->waiting
) >= 1);
250 int pa_fdsem_try(pa_fdsem
*f
) {
255 if (pa_atomic_cmpxchg(&f
->data
->signalled
, 1, 0))
261 int pa_fdsem_get(pa_fdsem
*f
) {
264 #ifdef HAVE_SYS_EVENTFD_H
272 int pa_fdsem_before_poll(pa_fdsem
*f
) {
277 if (pa_atomic_cmpxchg(&f
->data
->signalled
, 1, 0))
280 pa_atomic_inc(&f
->data
->waiting
);
282 if (pa_atomic_cmpxchg(&f
->data
->signalled
, 1, 0)) {
283 pa_assert_se(pa_atomic_dec(&f
->data
->waiting
) >= 1);
289 int pa_fdsem_after_poll(pa_fdsem
*f
) {
292 pa_assert_se(pa_atomic_dec(&f
->data
->waiting
) >= 1);
296 if (pa_atomic_cmpxchg(&f
->data
->signalled
, 1, 0))