add a threading primitive API

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1344 fefdeb5f-60dc-0310-8127-8f9354f1896f

src/pulsecore/thread-posix.c

@@ -0,0 +1,146 @@
+/* $Id$ */
+
+/***
+  This file is part of PulseAudio.
+ 
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as published
+  by the Free Software Foundation; either version 2 of the License,
+  or (at your option) any later version.
+ 
+  PulseAudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public License
+  along with PulseAudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <assert.h>
+#include <pthread.h>
+#include <atomic_ops.h>
+
+#include <pulse/xmalloc.h>
+
+#include "thread.h"
+
+#define ASSERT_SUCCESS(x) do { \
+    int _r = (x); \
+    assert(_r == 0); \
+} while(0)
+
+struct pa_thread {
+    pthread_t id;
+    pa_thread_func_t thread_func;
+    void *userdata;
+    AO_t running;
+};
+
+struct pa_tls {
+    pthread_key_t key;
+};
+
+static pa_tls *thread_tls;
+static pthread_once_t thread_tls_once = PTHREAD_ONCE_INIT;
+
+static void thread_tls_once_func(void) {
+    thread_tls = pa_tls_new(NULL);
+    assert(thread_tls);
+}
+
+static void* internal_thread_func(void *userdata) {
+    pa_thread *t = userdata;
+    assert(t);
+
+    t->id = pthread_self();
+
+    ASSERT_SUCCESS(pthread_once(&thread_tls_once, thread_tls_once_func));
+    pa_tls_set(thread_tls, t);
+    
+    AO_store_release_write(&t->running, 1);
+    t->thread_func(t->userdata);
+    AO_store_release_write(&t->running, 0);
+    
+    return NULL;
+}
+
+pa_thread* pa_thread_new(pa_thread_func_t thread_func, void *userdata) {
+    pa_thread *t;
+
+    t = pa_xnew(pa_thread, 1);
+    t->thread_func = thread_func;
+    t->userdata = userdata;
+
+    if (pthread_create(&t->id, NULL, internal_thread_func, t) < 0) {
+        pa_xfree(t);
+        return NULL;
+    }
+
+    return t;
+}
+
+int pa_thread_is_running(pa_thread *t) {
+    assert(t);
+
+    return !!AO_load_acquire_read(&t->running);
+}
+
+void pa_thread_free(pa_thread *t) {
+    assert(t);
+    
+    pa_thread_join(t);
+    pa_xfree(t);
+}
+
+int pa_thread_join(pa_thread *t) {
+    assert(t);
+    
+    return pthread_join(t->id, NULL);
+}
+
+pa_thread* pa_thread_self(void) {
+    ASSERT_SUCCESS(pthread_once(&thread_tls_once, thread_tls_once_func));
+    return pa_tls_get(thread_tls);
+}
+
+pa_tls* pa_tls_new(pa_free_cb_t free_cb) {
+    pa_tls *t;
+
+    t = pa_xnew(pa_tls, 1);
+
+    if (pthread_key_create(&t->key, free_cb) < 0) {
+        pa_xfree(t);
+        return NULL;
+    }
+        
+    return t;
+}
+
+void pa_tls_free(pa_tls *t) {
+    assert(t);
+
+    ASSERT_SUCCESS(pthread_key_delete(t->key));
+    pa_xfree(t);
+}
+
+void *pa_tls_get(pa_tls *t) {
+    assert(t);
+    
+    return pthread_getspecific(t->key);
+}
+
+void *pa_tls_set(pa_tls *t, void *userdata) {
+    void *r;
+    
+    r = pthread_getspecific(t->key);
+    ASSERT_SUCCESS(pthread_setspecific(t->key, userdata));
+    return r;
+}
+