From d0c79f7fe0954b5d607e4190d26bb6b5ba75ceaf Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@nicira.com>
Date: Fri, 26 Apr 2013 13:07:33 -0700
Subject: [PATCH] ofp-msgs: Make alloc_xid() thread-safe.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Andy Zhou <azhou@nicira.com>
---
 lib/ofp-msgs.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/lib/ofp-msgs.c b/lib/ofp-msgs.c
index 5e043d245..8bb1754f6 100644
--- a/lib/ofp-msgs.c
+++ b/lib/ofp-msgs.c
@@ -111,7 +111,14 @@ static ovs_be32
 alloc_xid(void)
 {
     static uint32_t next_xid = 1;
-    return htonl(next_xid++);
+    static pthread_mutex_t mutex = PTHREAD_ADAPTIVE_MUTEX_INITIALIZER;
+    uint32_t xid;
+
+    xpthread_mutex_lock(&mutex);
+    xid = next_xid++;
+    xpthread_mutex_unlock(&mutex);
+
+    return htonl(xid);
 }
 
 static uint32_t
-- 
2.47.0