code.delx.au - pulseaudio/blob - src/pulsecore/thread-posix.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   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 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 <assert.h>
  27 #include <pthread.h>
  28 #include <sched.h>
  29
  30 #include <atomic_ops.h>
  31
  32 #include <pulse/xmalloc.h>
  33
  34 #include "thread.h"
  35
  36 #define ASSERT_SUCCESS(x) do { \
  37     int _r = (x); \
  38     assert(_r == 0); \
  39 } while(0)
  40
  41 struct pa_thread {
  42     pthread_t id;
  43     pa_thread_func_t thread_func;
  44     void *userdata;
  45     AO_t running;
  46 };
  47
  48 struct pa_tls {
  49     pthread_key_t key;
  50 };
  51
  52 static pa_tls *thread_tls;
  53 static pthread_once_t thread_tls_once = PTHREAD_ONCE_INIT;
  54
  55 static void thread_tls_once_func(void) {
  56     thread_tls = pa_tls_new(NULL);
  57     assert(thread_tls);
  58 }
  59
  60 static void* internal_thread_func(void *userdata) {
  61     pa_thread *t = userdata;
  62     assert(t);
  63
  64     t->id = pthread_self();
  65
  66     ASSERT_SUCCESS(pthread_once(&thread_tls_once, thread_tls_once_func));
  67     pa_tls_set(thread_tls, t);
  68
  69     AO_fetch_and_add1_full(&t->running);
  70     t->thread_func(t->userdata);
  71     AO_fetch_and_add_full(&t->running, (AO_t) -2);
  72
  73     return NULL;
  74 }
  75
  76 pa_thread* pa_thread_new(pa_thread_func_t thread_func, void *userdata) {
  77     pa_thread *t;
  78
  79     t = pa_xnew(pa_thread, 1);
  80     t->thread_func = thread_func;
  81     t->userdata = userdata;
  82     AO_store_full(&t->running, 0);
  83
  84     if (pthread_create(&t->id, NULL, internal_thread_func, t) < 0) {
  85         pa_xfree(t);
  86         return NULL;
  87     }
  88
  89     AO_fetch_and_add1_full(&t->running);
  90
  91     return t;
  92 }
  93
  94 int pa_thread_is_running(pa_thread *t) {
  95     AO_t r;
  96     assert(t);
  97
  98     r = AO_load_full(&t->running);
  99     return r == 1 || r == 2;
 100 }
 101
 102 void pa_thread_free(pa_thread *t) {
 103     assert(t);
 104
 105     pa_thread_join(t);
 106     pa_xfree(t);
 107 }
 108
 109 int pa_thread_join(pa_thread *t) {
 110     assert(t);
 111
 112     return pthread_join(t->id, NULL);
 113 }
 114
 115 pa_thread* pa_thread_self(void) {
 116     ASSERT_SUCCESS(pthread_once(&thread_tls_once, thread_tls_once_func));
 117     return pa_tls_get(thread_tls);
 118 }
 119
 120 void pa_thread_yield(void) {
 121 #ifdef HAVE_PTHREAD_YIELD
 122     pthread_yield();
 123 #else
 124     sched_yield();
 125 #endif
 126 }
 127
 128 pa_tls* pa_tls_new(pa_free_cb_t free_cb) {
 129     pa_tls *t;
 130
 131     t = pa_xnew(pa_tls, 1);
 132
 133     if (pthread_key_create(&t->key, free_cb) < 0) {
 134         pa_xfree(t);
 135         return NULL;
 136     }
 137
 138     return t;
 139 }
 140
 141 void pa_tls_free(pa_tls *t) {
 142     assert(t);
 143
 144     ASSERT_SUCCESS(pthread_key_delete(t->key));
 145     pa_xfree(t);
 146 }
 147
 148 void *pa_tls_get(pa_tls *t) {
 149     assert(t);
 150
 151     return pthread_getspecific(t->key);
 152 }
 153
 154 void *pa_tls_set(pa_tls *t, void *userdata) {
 155     void *r;
 156
 157     r = pthread_getspecific(t->key);
 158     ASSERT_SUCCESS(pthread_setspecific(t->key, userdata));
 159     return r;
 160 }
 161