From 9c9eb86b2feb6fbfe336fe40a1cf6962d42b606c Mon Sep 17 00:00:00 2001
From: Joel Dice <git@seibutsu.mailsnare.net>
Date: Thu, 16 Jul 2009 11:51:35 -0600
Subject: [PATCH] fix deadlock in allocate3 when another thread wants to enter
 the exclusive state

---
 src/machine.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/machine.cpp b/src/machine.cpp
index c0ee2be304..2fb5fbb1cc 100644
--- a/src/machine.cpp
+++ b/src/machine.cpp
@@ -2055,6 +2055,10 @@ allocate3(Thread* t, Allocator* allocator, Machine::AllocationType type,
     // another thread wants to enter the exclusive state, either for a
     // collection or some other reason.  We give it a chance here.
     ENTER(t, Thread::IdleState);
+
+    while (t->m->exclusive) {
+      t->m->stateLock->wait(t->systemThread, 0);
+    }
   }
   
   switch (type) {