[glib] Fix an invalid non-looping use of GCond

[Ryan Lortie <ryanl src gnome org>]

commit 449a1e8bfd0ea7e8db1e3a436cf182b5cc71aa75
Author: Ryan Lortie <desrt desrt ca>
Date:   Tue Oct 4 11:07:15 2011 -0400

    Fix an invalid non-looping use of GCond
    
    The GIOScheduler was using a GCond in a way that didn't deal with the
    possibility of spurious wakeups.  Add an explicit predicate and a loop.
    
    Problem caught by Matthias Clasen.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=660739

 gio/gioscheduler.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/gio/gioscheduler.c b/gio/gioscheduler.c
index 9f83977..e75e330 100644
--- a/gio/gioscheduler.c
+++ b/gio/gioscheduler.c
@@ -278,6 +278,7 @@ typedef struct {
 
   GMutex ack_lock;
   GCond ack_condition;
+  gboolean ack;
 } MainLoopProxy;
 
 static gboolean
@@ -291,6 +292,7 @@ mainloop_proxy_func (gpointer data)
     proxy->notify (proxy->data);
 
   g_mutex_lock (&proxy->ack_lock);
+  proxy->ack = TRUE;
   g_cond_signal (&proxy->ack_condition);
   g_mutex_unlock (&proxy->ack_lock);
 
@@ -347,7 +349,8 @@ g_io_scheduler_job_send_to_mainloop (GIOSchedulerJob *job,
   g_source_attach (source, job->context);
   g_source_unref (source);
 
-  g_cond_wait (&proxy->ack_condition, &proxy->ack_lock);
+  while (!proxy->ack)
+    g_cond_wait (&proxy->ack_condition, &proxy->ack_lock);
   g_mutex_unlock (&proxy->ack_lock);
 
   ret_val = proxy->ret_val;