From 366e6d7e90d3bebc98a1af3cfb04b4cfc8cff6f5 Mon Sep 17 00:00:00 2001

From: Arun Raghavan <arun.raghavan@collabora.co.uk>

Date: Sun, 6 Dec 2009 12:20:53 +0530

Subject: [PATCH 21/62] Mark shared variables as volatile

'n_waiting' and 'n_waiting_for_accept' may be accessed from mulitple

threads, and thus need to be marked as volatile to suppres certain

compiler optimisations. All uses are protected by a mutex, so we don't

need to worry about cache issues (added documentation for this as well).

This addresses bug #738.

---

 src/pulse/thread-mainloop.c |    5 ++++-

 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/src/pulse/thread-mainloop.c b/src/pulse/thread-mainloop.c

index a2b98ce..14ed926 100644

--- a/src/pulse/thread-mainloop.c

+++ b/src/pulse/thread-mainloop.c

@@ -51,7 +51,7 @@

 struct pa_threaded_mainloop {

     pa_mainloop *real_mainloop;

-    int n_waiting, n_waiting_for_accept;

+    volatile int n_waiting, n_waiting_for_accept;

     pa_thread* thread;

     pa_mutex* mutex;

@@ -185,6 +185,7 @@ void pa_threaded_mainloop_unlock(pa_threaded_mainloop *m) {

     pa_mutex_unlock(m->mutex);

 }

+/* Called with the lock taken */

 void pa_threaded_mainloop_signal(pa_threaded_mainloop *m, int wait_for_accept) {

     pa_assert(m);

@@ -198,6 +199,7 @@ void pa_threaded_mainloop_signal(pa_threaded_mainloop *m, int wait_for_accept) {

     }

 }

+/* Called with the lock taken */

 void pa_threaded_mainloop_wait(pa_threaded_mainloop *m) {

     pa_assert(m);

@@ -212,6 +214,7 @@ void pa_threaded_mainloop_wait(pa_threaded_mainloop *m) {

     m->n_waiting --;

 }

+/* Called with the lock taken */

 void pa_threaded_mainloop_accept(pa_threaded_mainloop *m) {

     pa_assert(m);

-- 

1.7.0