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 };
  45
  46 struct pa_tls {
  47     pthread_key_t key;
  48 };
  49
  50 static void thread_free_cb(void *p) {
  51     pa_thread *t = p;
  52
  53     pa_assert(t);
  54
  55     if (!t->thread_func)
  56         /* This is a foreign thread, we need to free the struct */
  57         pa_xfree(t);
  58 }
  59
  60 PA_STATIC_TLS_DECLARE(current_thread, thread_free_cb);
  61
  62 static void* internal_thread_func(void *userdata) {
  63     pa_thread *t = userdata;
  64     pa_assert(t);
  65
  66     t->id = pthread_self();
  67
  68     PA_STATIC_TLS_SET(current_thread, t);
  69
  70     pa_atomic_inc(&t->running);
  71     t->thread_func(t->userdata);
  72     pa_atomic_sub(&t->running, 2);
  73
  74     return NULL;
  75 }
  76
  77 pa_thread* pa_thread_new(pa_thread_func_t thread_func, void *userdata) {
  78     pa_thread *t;
  79
  80     pa_assert(thread_func);
  81
  82     t = pa_xnew(pa_thread, 1);
  83     t->thread_func = thread_func;
  84     t->userdata = userdata;
  85     pa_atomic_store(&t->running, 0);
  86
  87     if (pthread_create(&t->id, NULL, internal_thread_func, t) < 0) {
  88         pa_xfree(t);
  89         return NULL;
  90     }
  91
  92     pa_atomic_inc(&t->running);
  93
  94     return t;
  95 }
  96
  97 int pa_thread_is_running(pa_thread *t) {
  98     pa_assert(t);
  99
 100     /* Unfortunately there is no way to tell whether a "foreign"
 101      * thread is still running. See
 102      * http://udrepper.livejournal.com/16844.html for more
 103      * information */
 104     pa_assert(t->thread_func);
 105
 106     return pa_atomic_load(&t->running) > 0;
 107 }
 108
 109 void pa_thread_free(pa_thread *t) {
 110     pa_assert(t);
 111
 112     pa_thread_join(t);
 113     pa_xfree(t);
 114 }
 115
 116 int pa_thread_join(pa_thread *t) {
 117     pa_assert(t);
 118
 119     return pthread_join(t->id, NULL);
 120 }
 121
 122 pa_thread* pa_thread_self(void) {
 123     pa_thread *t;
 124
 125     if ((t = PA_STATIC_TLS_GET(current_thread)))
 126         return t;
 127
 128     /* This is a foreign thread, let's create a pthread structure to
 129      * make sure that we can always return a sensible pointer */
 130
 131     t = pa_xnew(pa_thread, 1);
 132     t->id = pthread_self();
 133     t->thread_func = NULL;
 134     t->userdata = NULL;
 135     pa_atomic_store(&t->running, 2);
 136
 137     PA_STATIC_TLS_SET(current_thread, t);
 138
 139     return t;
 140 }
 141
 142 void* pa_thread_get_data(pa_thread *t) {
 143     pa_assert(t);
 144
 145     return t->userdata;
 146 }
 147
 148 void pa_thread_set_data(pa_thread *t, void *userdata) {
 149     pa_assert(t);
 150
 151     t->userdata = userdata;
 152 }
 153
 154 void pa_thread_yield(void) {
 155 #ifdef HAVE_PTHREAD_YIELD
 156     pthread_yield();
 157 #else
 158     pa_assert_se(sched_yield() == 0);
 159 #endif
 160 }
 161
 162 pa_tls* pa_tls_new(pa_free_cb_t free_cb) {
 163     pa_tls *t;
 164
 165     t = pa_xnew(pa_tls, 1);
 166
 167     if (pthread_key_create(&t->key, free_cb) < 0) {
 168         pa_xfree(t);
 169         return NULL;
 170     }
 171
 172     return t;
 173 }
 174
 175 void pa_tls_free(pa_tls *t) {
 176     pa_assert(t);
 177
 178     pa_assert_se(pthread_key_delete(t->key) == 0);
 179     pa_xfree(t);
 180 }
 181
 182 void *pa_tls_get(pa_tls *t) {
 183     pa_assert(t);
 184
 185     return pthread_getspecific(t->key);
 186 }
 187
 188 void *pa_tls_set(pa_tls *t, void *userdata) {
 189     void *r;
 190
 191     r = pthread_getspecific(t->key);
 192     pa_assert_se(pthread_setspecific(t->key, userdata) == 0);
 193     return r;
 194 }
 195