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

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of PulseAudio.
   5
   6   Copyright 2006 Lennart Poettering
   7   Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
   8
   9   PulseAudio is free software; you can redistribute it and/or modify
  10   it under the terms of the GNU Lesser General Public License as published
  11   by the Free Software Foundation; either version 2 of the License,
  12   or (at your option) any later version.
  13
  14   PulseAudio is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with PulseAudio; if not, write to the Free Software
  21   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  22   USA.
  23 ***/
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #include <pthread.h>
  30 #include <sched.h>
  31 #include <errno.h>
  32
  33 #include <pulse/xmalloc.h>
  34 #include <pulsecore/mutex.h>
  35 #include <pulsecore/once.h>
  36 #include <pulsecore/atomic.h>
  37 #include <pulsecore/macro.h>
  38
  39 #include "thread.h"
  40
  41 struct pa_thread {
  42     pthread_t id;
  43     pa_thread_func_t thread_func;
  44     void *userdata;
  45     pa_atomic_t running;
  46 };
  47
  48 struct pa_tls {
  49     pthread_key_t key;
  50 };
  51
  52 static void thread_free_cb(void *p) {
  53     pa_thread *t = p;
  54
  55     pa_assert(t);
  56
  57     if (!t->thread_func)
  58         /* This is a foreign thread, we need to free the struct */
  59         pa_xfree(t);
  60 }
  61
  62 PA_STATIC_TLS_DECLARE(current_thread, thread_free_cb);
  63
  64 static void* internal_thread_func(void *userdata) {
  65     pa_thread *t = userdata;
  66     pa_assert(t);
  67
  68     t->id = pthread_self();
  69
  70     PA_STATIC_TLS_SET(current_thread, t);
  71
  72     pa_atomic_inc(&t->running);
  73     t->thread_func(t->userdata);
  74     pa_atomic_sub(&t->running, 2);
  75
  76     return NULL;
  77 }
  78
  79 pa_thread* pa_thread_new(pa_thread_func_t thread_func, void *userdata) {
  80     pa_thread *t;
  81
  82     pa_assert(thread_func);
  83
  84     t = pa_xnew(pa_thread, 1);
  85     t->thread_func = thread_func;
  86     t->userdata = userdata;
  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
 121     return pthread_join(t->id, NULL);
 122 }
 123
 124 pa_thread* pa_thread_self(void) {
 125     pa_thread *t;
 126
 127     if ((t = PA_STATIC_TLS_GET(current_thread)))
 128         return t;
 129
 130     /* This is a foreign thread, let's create a pthread structure to
 131      * make sure that we can always return a sensible pointer */
 132
 133     t = pa_xnew(pa_thread, 1);
 134     t->id = pthread_self();
 135     t->thread_func = NULL;
 136     t->userdata = NULL;
 137     pa_atomic_store(&t->running, 2);
 138
 139     PA_STATIC_TLS_SET(current_thread, t);
 140
 141     return t;
 142 }
 143
 144 void* pa_thread_get_data(pa_thread *t) {
 145     pa_assert(t);
 146
 147     return t->userdata;
 148 }
 149
 150 void pa_thread_set_data(pa_thread *t, void *userdata) {
 151     pa_assert(t);
 152
 153     t->userdata = userdata;
 154 }
 155
 156 void pa_thread_yield(void) {
 157 #ifdef HAVE_PTHREAD_YIELD
 158     pthread_yield();
 159 #else
 160     pa_assert_se(sched_yield() == 0);
 161 #endif
 162 }
 163
 164 pa_tls* pa_tls_new(pa_free_cb_t free_cb) {
 165     pa_tls *t;
 166
 167     t = pa_xnew(pa_tls, 1);
 168
 169     if (pthread_key_create(&t->key, free_cb) < 0) {
 170         pa_xfree(t);
 171         return NULL;
 172     }
 173
 174     return t;
 175 }
 176
 177 void pa_tls_free(pa_tls *t) {
 178     pa_assert(t);
 179
 180     pa_assert_se(pthread_key_delete(t->key) == 0);
 181     pa_xfree(t);
 182 }
 183
 184 void *pa_tls_get(pa_tls *t) {
 185     pa_assert(t);
 186
 187     return pthread_getspecific(t->key);
 188 }
 189
 190 void *pa_tls_set(pa_tls *t, void *userdata) {
 191     void *r;
 192
 193     r = pthread_getspecific(t->key);
 194     pa_assert_se(pthread_setspecific(t->key, userdata) == 0);
 195     return r;
 196 }
 197