Wrap two pa_asyncmsq in a new pa_thread_mq object for bidirectional, lock-free communication between a main loop and a thread

git-svn-id: file:///home/lennart/svn/public/pulseaudio/branches/lennart@1622 fefdeb5f-60dc-0310-8127-8f9354f1896f

3 files changed, 169 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 6cb3f288..2d3af078 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -662,6 +662,7 @@ libpulsecore_la_SOURCES += \
 		pulsecore/flist.c pulsecore/flist.h \
 		pulsecore/asyncmsgq.c pulsecore/asyncmsgqq.h \
 		pulsecore/asyncq.c pulsecore/asyncq.h \
+		pulsecore/thread-mq.c pulsecore/thread-mq.h \
 		pulsecore/fdsem.c pulsecore/fdsem.h \
 		pulsecore/object.c pulsecore/object.h \
 		pulsecore/msgobject.c pulsecore/msgobject.h \
diff --git a/src/pulsecore/thread-mq.c b/src/pulsecore/thread-mq.c
new file mode 100644
index 00000000..224a14cb
--- /dev/null
+++ b/src/pulsecore/thread-mq.c
@@ -0,0 +1,119 @@
+/* $Id$ */
+
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2006 Lennart Poettering
+
+  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 2.1 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
+  Lesser 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 <unistd.h>
+#include <errno.h>
+
+#include <pulse/xmalloc.h>
+
+#include <pulsecore/atomic.h>
+#include <pulsecore/once.h>
+#include <pulsecore/log.h>
+#include <pulsecore/thread.h>
+#include <pulsecore/semaphore.h>
+#include <pulsecore/macro.h>
+#include <pulsecore/core-util.h>
+#include <pulsecore/flist.h>
+
+#include "thread-mq.h"
+
+static pa_once once = PA_ONCE_INIT;
+static pa_tls *tls;
+
+static void asyncmsgq_cb(pa_mainloop_api*api, pa_io_event* e, int fd, pa_io_event_flags_t events, void *userdata) {
+    pa_thread_mq *q = userdata;
+
+    pa_assert(pa_asyncmsgq_get_fd(q->outq) == fd);
+    pa_assert(events == PA_IO_EVENT_INPUT);
+
+    pa_asyncmsgq_after_poll(q->outq);
+
+    for (;;) {
+        pa_msgobject *object;
+        int code;
+        void *data;
+        int64_t offset;
+        pa_memchunk chunk;
+
+        /* Check whether there is a message for us to process */
+        while (pa_asyncmsgq_get(q->outq, &object, &code, &data, &offset, &chunk, 0) == 0) {
+            int ret;
+
+            ret = pa_asyncmsgq_dispatch(object, code, data, offset, &chunk);
+            pa_asyncmsgq_done(q->outq, ret);
+        }
+
+        if (pa_asyncmsgq_before_poll(q->outq) == 0)
+            break;
+    }
+}
+
+void pa_thread_mq_init(pa_thread_mq *q, pa_mainloop_api *mainloop) {
+    pa_assert(q);
+    pa_assert(mainloop);
+
+    q->mainloop = mainloop;
+    pa_assert_se(q->inq = pa_asyncmsgq_new(0));
+    pa_assert_se(q->outq = pa_asyncmsgq_new(0));
+    
+    pa_assert_se(pa_asyncmsgq_before_poll(q->outq) == 0);
+    pa_assert_se(q->io_event = mainloop->io_new(mainloop, pa_asyncmsgq_get_fd(q->outq), PA_IO_EVENT_INPUT, asyncmsgq_cb, q));
+}
+
+void pa_thread_mq_done(pa_thread_mq *q) {
+    pa_assert(q);
+
+    q->mainloop->io_free(q->io_event);
+    q->io_event = NULL;
+
+    pa_asyncmsgq_after_poll(q->outq);
+    pa_asyncmsgq_free(q->inq);
+    pa_asyncmsgq_free(q->outq);
+    q->inq = q->outq = NULL;
+    
+    q->mainloop = NULL;
+}
+
+static void init_tls(void) {
+    tls = pa_tls_new(NULL);
+}
+
+void pa_thread_mq_install(pa_thread_mq *q) {
+    pa_assert(q);
+
+    pa_run_once(&once, init_tls);
+    pa_tls_set(tls, q);
+}
+
+pa_thread_mq *pa_thread_mq_get(void) {
+    pa_thread_mq *q;
+
+    pa_run_once(&once, init_tls);
+    pa_assert_se(q = pa_tls_get(tls));
+    return q;
+}
+
diff --git a/src/pulsecore/thread-mq.h b/src/pulsecore/thread-mq.h
new file mode 100644
index 00000000..13b6e01f
--- /dev/null
+++ b/src/pulsecore/thread-mq.h
@@ -0,0 +1,49 @@
+#ifndef foopulsethreadmqhfoo
+#define foopulsethreadmqhfoo
+
+/* $Id$ */
+
+/***
+  This file is part of PulseAudio.
+
+  Copyright 2004-2006 Lennart Poettering
+
+  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 2.1 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
+  Lesser 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.
+***/
+
+#include <pulse/mainloop-api.h>
+#include <pulsecore/asyncmsgq.h>
+
+/* Two way communication between a thread and a mainloop. Before the
+ * thread is started a pa_pthread_mq should be initialized and than
+ * attached to the thread using pa_thread_mq_install(). */
+
+typedef struct pa_thread_mq {
+    pa_mainloop_api *mainloop;
+    pa_asyncmsgq *inq, *outq;
+    pa_io_event *io_event;
+} pa_thread_mq;
+
+void pa_thread_mq_init(pa_thread_mq *q, pa_mainloop_api *mainloop);
+void pa_thread_mq_done(pa_thread_mq *q);
+
+/* Install the specified pa_thread_mq object for the current thread */
+void pa_thread_mq_install(pa_thread_mq *q);
+
+/* Return the pa_thread_mq object that is set for the current thread */
+pa_thread_mq *pa_thread_mq_get(void);
+
+#endif