From e92674cb7337355dc4dd6317219010e5d1ce7e1c Mon Sep 17 00:00:00 2001
From: Joel Dice <joel.dice@gmail.com>
Date: Tue, 2 Feb 2010 12:24:05 -0700
Subject: [PATCH] fix race condition in monitorWait

We don't want to check Thread::waiting until we have re-acquired the
monitor, since another thread might notify us between releasing
Thread::lock and acquiring the monitor.
---
 src/machine.h | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/machine.h b/src/machine.h
index 24fe9ab70b..441eecc6a0 100644
--- a/src/machine.h
+++ b/src/machine.h
@@ -2508,7 +2508,6 @@ monitorWait(Thread* t, object monitor, int64_t time)
 
   bool interrupted;
   unsigned depth;
-  bool stillWaiting;
 
   PROTECT(t, monitor);
 
@@ -2524,13 +2523,11 @@ monitorWait(Thread* t, object monitor, int64_t time)
     ENTER(t, Thread::IdleState);
 
     interrupted = t->lock->wait(t->systemThread, time);
-
-    stillWaiting = t->waiting;
   }
 
   monitorAcquire(t, monitor);
 
-  if (stillWaiting) {
+  if (t->waiting) {
     monitorRemoveWait(t, monitor);
   }