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       1                 :            : /***
       2                 :            :   This file is part of PulseAudio.
       3                 :            : 
       4                 :            :   Copyright 2006 Lennart Poettering
       5                 :            : 
       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 published
       8                 :            :   by the Free Software Foundation; either version 2.1 of the License,
       9                 :            :   or (at your option) any later version.
      10                 :            : 
      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                 :            :   General Public License for more details.
      15                 :            : 
      16                 :            :   You should have received a copy of the GNU Lesser General Public License
      17                 :            :   along with PulseAudio; if not, write to the Free Software
      18                 :            :   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
      19                 :            :   USA.
      20                 :            : ***/
      21                 :            : 
      22                 :            : #ifdef HAVE_CONFIG_H
      23                 :            : #include <config.h>
      24                 :            : #endif
      25                 :            : 
      26                 :            : #include <errno.h>
      27                 :            : #include <pthread.h>
      28                 :            : #include <semaphore.h>
      29                 :            : 
      30                 :            : #include <pulse/xmalloc.h>
      31                 :            : #include <pulsecore/macro.h>
      32                 :            : 
      33                 :            : #include "semaphore.h"
      34                 :            : 
      35                 :            : struct pa_semaphore {
      36                 :            :     sem_t sem;
      37                 :            : };
      38                 :            : 
      39                 :         10 : pa_semaphore* pa_semaphore_new(unsigned value) {
      40                 :            :     pa_semaphore *s;
      41                 :            : 
      42                 :         10 :     s = pa_xnew(pa_semaphore, 1);
      43         [ -  + ]:         10 :     pa_assert_se(sem_init(&s->sem, 0, value) == 0);
      44                 :         10 :     return s;
      45                 :            : }
      46                 :            : 
      47                 :          6 : void pa_semaphore_free(pa_semaphore *s) {
      48         [ -  + ]:          6 :     pa_assert(s);
      49         [ -  + ]:          6 :     pa_assert_se(sem_destroy(&s->sem) == 0);
      50                 :          6 :     pa_xfree(s);
      51                 :          6 : }
      52                 :            : 
      53                 :          2 : void pa_semaphore_post(pa_semaphore *s) {
      54         [ -  + ]:          2 :     pa_assert(s);
      55         [ -  + ]:          2 :     pa_assert_se(sem_post(&s->sem) == 0);
      56                 :          2 : }
      57                 :            : 
      58                 :          1 : void pa_semaphore_wait(pa_semaphore *s) {
      59                 :            :     int ret;
      60         [ -  + ]:          1 :     pa_assert(s);
      61                 :            : 
      62                 :            :     do {
      63                 :          1 :         ret = sem_wait(&s->sem);
      64 [ -  + ][ #  # ]:          1 :     } while (ret < 0 && errno == EINTR);
      65                 :            : 
      66         [ -  + ]:          1 :     pa_assert(ret == 0);
      67                 :          1 : }
      68                 :            : 
      69                 :          0 : pa_semaphore* pa_static_semaphore_get(pa_static_semaphore *s, unsigned value) {
      70                 :            :     pa_semaphore *m;
      71                 :            : 
      72         [ #  # ]:          0 :     pa_assert(s);
      73                 :            : 
      74                 :            :     /* First, check if already initialized and short cut */
      75         [ #  # ]:          0 :     if ((m = pa_atomic_ptr_load(&s->ptr)))
      76                 :            :         return m;
      77                 :            : 
      78                 :            :     /* OK, not initialized, so let's allocate, and fill in */
      79                 :          0 :     m = pa_semaphore_new(value);
      80         [ #  # ]:          0 :     if ((pa_atomic_ptr_cmpxchg(&s->ptr, NULL, m)))
      81                 :            :         return m;
      82                 :            : 
      83                 :          0 :     pa_semaphore_free(m);
      84                 :            : 
      85                 :            :     /* Him, filling in failed, so someone else must have filled in
      86                 :            :      * already */
      87         [ #  # ]:          0 :     pa_assert_se(m = pa_atomic_ptr_load(&s->ptr));
      88                 :            :     return m;
      89                 :            : }