add new threaded main loop implementation (with test/example)

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@823 fefdeb5f-60dc-0310-8127-8f9354f1896f

src/polyp/thread-mainloop.c

@@ -0,0 +1,203 @@
+/* $Id$ */
+
+/***
+  This file is part of polypaudio.
+ 
+  polypaudio 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.
+ 
+  polypaudio 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 polypaudio; 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 <pthread.h>
+#include <assert.h>
+#include <signal.h>
+#include <sys/poll.h>
+#include <stdio.h>
+
+#include <polypcore/xmalloc.h>
+
+#include "mainloop.h"
+#include "thread-mainloop.h"
+
+struct pa_threaded_mainloop {
+    pa_mainloop *real_mainloop;
+    pthread_t thread_id;
+    pthread_mutex_t mutex;
+    pthread_cond_t cond;
+    int thread_running;
+};
+
+static int poll_func(struct pollfd *ufds, unsigned long nfds, int timeout, void *userdata) {
+    pthread_mutex_t *mutex = userdata;
+    int r;
+
+    assert(mutex);
+    
+    /* Before entering poll() we unlock the mutex, so that
+     * avahi_simple_poll_quit() can succeed from another thread. */
+
+    pthread_mutex_unlock(mutex);
+    r = poll(ufds, nfds, timeout);
+    pthread_mutex_lock(mutex);
+
+    return r;
+}
+
+static void* thread(void *userdata){
+    pa_threaded_mainloop *m = userdata;
+    sigset_t mask;
+
+    /* Make sure that signals are delivered to the main thread */
+    sigfillset(&mask);
+    pthread_sigmask(SIG_BLOCK, &mask, NULL);
+
+    pthread_mutex_lock(&m->mutex);
+    pa_mainloop_run(m->real_mainloop, NULL);
+    pthread_mutex_unlock(&m->mutex);
+
+    return NULL;
+}
+
+pa_threaded_mainloop *pa_threaded_mainloop_new(void) {
+    pa_threaded_mainloop *m;
+    pthread_mutexattr_t a;
+
+    m = pa_xnew(pa_threaded_mainloop, 1);
+
+    if (!(m->real_mainloop = pa_mainloop_new())) {
+        pa_xfree(m);
+        return NULL;
+    }
+
+    pa_mainloop_set_poll_func(m->real_mainloop, poll_func, &m->mutex);
+
+    pthread_mutexattr_init(&a);
+    pthread_mutexattr_settype(&a, PTHREAD_MUTEX_RECURSIVE);
+    pthread_mutex_init(&m->mutex, NULL);
+    pthread_mutexattr_destroy(&a);
+    
+    pthread_cond_init(&m->cond, NULL);
+    m->thread_running = 0;
+
+    return m;
+}
+
+void pa_threaded_mainloop_free(pa_threaded_mainloop* m) {
+    assert(m);
+
+    /* Make sure that this function is not called from the helper thread */
+    assert(!m->thread_running || !pthread_equal(pthread_self(), m->thread_id));
+
+    if (m->thread_running)
+        pa_threaded_mainloop_stop(m);
+
+    if (m->real_mainloop)
+        pa_mainloop_free(m->real_mainloop);
+
+    pthread_mutex_destroy(&m->mutex);
+    pthread_cond_destroy(&m->cond);
+    
+    pa_xfree(m);
+}
+
+int pa_threaded_mainloop_start(pa_threaded_mainloop *m) {
+    assert(m);
+
+    assert(!m->thread_running);
+
+    pthread_mutex_lock(&m->mutex);
+
+    if (pthread_create(&m->thread_id, NULL, thread, m) < 0) {
+        pthread_mutex_unlock(&m->mutex);
+        return -1;
+    }
+
+    m->thread_running = 1;
+    
+    pthread_mutex_unlock(&m->mutex);
+
+    return 0;
+}
+
+void pa_threaded_mainloop_stop(pa_threaded_mainloop *m) {
+    assert(m);
+
+    if (!m->thread_running)
+        return;
+
+    /* Make sure that this function is not called from the helper thread */
+    assert(!pthread_equal(pthread_self(), m->thread_id));
+
+    pthread_mutex_lock(&m->mutex);
+    pa_mainloop_quit(m->real_mainloop, 0);
+    pthread_mutex_unlock(&m->mutex);
+
+    pthread_join(m->thread_id, NULL);
+    m->thread_running = 0;
+
+    return;
+}
+
+void pa_threaded_mainloop_lock(pa_threaded_mainloop *m) {
+    assert(m);
+    
+    /* Make sure that this function is not called from the helper thread */
+    assert(!m->thread_running || !pthread_equal(pthread_self(), m->thread_id));
+
+    pthread_mutex_lock(&m->mutex);
+}
+
+void pa_threaded_mainloop_unlock(pa_threaded_mainloop *m) {
+    assert(m);
+    
+    /* Make sure that this function is not called from the helper thread */
+    assert(!m->thread_running || !pthread_equal(pthread_self(), m->thread_id));
+
+    pthread_mutex_unlock(&m->mutex);
+}
+
+void pa_threaded_mainloop_signal(pa_threaded_mainloop *m) {
+    assert(m);
+    
+    /* Make sure that this function is called from the helper thread */
+    assert(m->thread_running && pthread_equal(pthread_self(), m->thread_id));
+
+    pthread_cond_broadcast(&m->cond);
+}
+
+void pa_threaded_mainloop_wait(pa_threaded_mainloop *m) {
+    assert(m);
+    
+    /* Make sure that this function is not called from the helper thread */
+    assert(!m->thread_running || !pthread_equal(pthread_self(), m->thread_id));
+
+    pthread_cond_wait(&m->cond, &m->mutex);
+}
+
+int pa_threaded_mainloop_get_retval(pa_threaded_mainloop *m) {
+    assert(m);
+
+    return pa_mainloop_get_retval(m->real_mainloop);
+}
+
+pa_mainloop_api* pa_threaded_mainloop_get_api(pa_threaded_mainloop*m) {
+    assert(m);
+
+    return pa_mainloop_get_api(m->real_mainloop);
+}
+