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

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2006 Lennart Poettering
   5   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   6
   7   PulseAudio is free software; you can redistribute it and/or modify
   8   it under the terms of the GNU Lesser General Public License as published
   9   by the Free Software Foundation; either version 2 of the License,
  10   or (at your option) any later version.
  11
  12   PulseAudio is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with PulseAudio; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  20   USA.
  21 ***/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <pthread.h>
  28 #include <sched.h>
  29 #include <errno.h>
  30
  31 #include <pulse/xmalloc.h>
  32 #include <pulsecore/mutex.h>
  33 #include <pulsecore/once.h>
  34 #include <pulsecore/atomic.h>
  35 #include <pulsecore/macro.h>
  36
  37 #include "thread.h"
  38
  39 struct pa_thread {
  40     pthread_t id;
  41     pa_thread_func_t thread_func;
  42     void *userdata;
  43     pa_atomic_t running;
  44     pa_bool_t joined;
  45 };
  46
  47 struct pa_tls {
  48     pthread_key_t key;
  49 };
  50
  51 static void thread_free_cb(void *p) {
  52     pa_thread *t = p;
  53
  54     pa_assert(t);
  55
  56     if (!t->thread_func)
  57         /* This is a foreign thread, we need to free the struct */
  58         pa_xfree(t);
  59 }
  60
  61 PA_STATIC_TLS_DECLARE(current_thread, thread_free_cb);
  62
  63 static void* internal_thread_func(void *userdata) {
  64     pa_thread *t = userdata;
  65     pa_assert(t);
  66
  67     t->id = pthread_self();
  68
  69     PA_STATIC_TLS_SET(current_thread, t);
  70
  71     pa_atomic_inc(&t->running);
  72     t->thread_func(t->userdata);
  73     pa_atomic_sub(&t->running, 2);
  74
  75     return NULL;
  76 }
  77
  78 pa_thread* pa_thread_new(pa_thread_func_t thread_func, void *userdata) {
  79     pa_thread *t;
  80
  81     pa_assert(thread_func);
  82
  83     t = pa_xnew(pa_thread, 1);
  84     t->thread_func = thread_func;
  85     t->userdata = userdata;
  86     t->joined = FALSE;
  87     pa_atomic_store(&t->running, 0);
  88
  89     if (pthread_create(&t->id, NULL, internal_thread_func, t) < 0) {
  90         pa_xfree(t);
  91         return NULL;
  92     }
  93
  94     pa_atomic_inc(&t->running);
  95
  96     return t;
  97 }
  98
  99 int pa_thread_is_running(pa_thread *t) {
 100     pa_assert(t);
 101
 102     /* Unfortunately there is no way to tell whether a "foreign"
 103      * thread is still running. See
 104      * http://udrepper.livejournal.com/16844.html for more
 105      * information */
 106     pa_assert(t->thread_func);
 107
 108     return pa_atomic_load(&t->running) > 0;
 109 }
 110
 111 void pa_thread_free(pa_thread *t) {
 112     pa_assert(t);
 113
 114     pa_thread_join(t);
 115     pa_xfree(t);
 116 }
 117
 118 int pa_thread_join(pa_thread *t) {
 119     pa_assert(t);
 120     pa_assert(t->thread_func);
 121
 122     if (t->joined)
 123         return -1;
 124
 125     t->joined = TRUE;
 126     return pthread_join(t->id, NULL);
 127 }
 128
 129 pa_thread* pa_thread_self(void) {
 130     pa_thread *t;
 131
 132     if ((t = PA_STATIC_TLS_GET(current_thread)))
 133         return t;
 134
 135     /* This is a foreign thread, let's create a pthread structure to
 136      * make sure that we can always return a sensible pointer */
 137
 138     t = pa_xnew(pa_thread, 1);
 139     t->id = pthread_self();
 140     t->thread_func = NULL;
 141     t->userdata = NULL;
 142     t->joined = TRUE;
 143     pa_atomic_store(&t->running, 2);
 144
 145     PA_STATIC_TLS_SET(current_thread, t);
 146
 147     return t;
 148 }
 149
 150 void* pa_thread_get_data(pa_thread *t) {
 151     pa_assert(t);
 152
 153     return t->userdata;
 154 }
 155
 156 void pa_thread_set_data(pa_thread *t, void *userdata) {
 157     pa_assert(t);
 158
 159     t->userdata = userdata;
 160 }
 161
 162 void pa_thread_yield(void) {
 163 #ifdef HAVE_PTHREAD_YIELD
 164     pthread_yield();
 165 #else
 166     pa_assert_se(sched_yield() == 0);
 167 #endif
 168 }
 169
 170 pa_tls* pa_tls_new(pa_free_cb_t free_cb) {
 171     pa_tls *t;
 172
 173     t = pa_xnew(pa_tls, 1);
 174
 175     if (pthread_key_create(&t->key, free_cb) < 0) {
 176         pa_xfree(t);
 177         return NULL;
 178     }
 179
 180     return t;
 181 }
 182
 183 void pa_tls_free(pa_tls *t) {
 184     pa_assert(t);
 185
 186     pa_assert_se(pthread_key_delete(t->key) == 0);
 187     pa_xfree(t);
 188 }
 189
 190 void *pa_tls_get(pa_tls *t) {
 191     pa_assert(t);
 192
 193     return pthread_getspecific(t->key);
 194 }
 195
 196 void *pa_tls_set(pa_tls *t, void *userdata) {
 197     void *r;
 198
 199     r = pthread_getspecific(t->key);
 200     pa_assert_se(pthread_setspecific(t->key, userdata) == 0);
 201     return r;
 202 }