From 1800efc13806440867b92758d01f0ce97e239e36 Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Fri, 18 Oct 2013 17:10:03 +0200
Subject: [PATCH] unix: fix non-synchronized access in signal.c

Check the return value of uv__signal_lock(); don't mutate the signal
watcher tree in the signal handler if we failed to acquire the lock.
---
 src/unix/signal.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/unix/signal.c b/src/unix/signal.c
index 22c7783b..aa84ff2f 100644
--- a/src/unix/signal.c
+++ b/src/unix/signal.c
@@ -141,7 +141,10 @@ static void uv__signal_handler(int signum) {
   saved_errno = errno;
   memset(&msg, 0, sizeof msg);
 
-  uv__signal_lock();
+  if (uv__signal_lock()) {
+    errno = saved_errno;
+    return;
+  }
 
   for (handle = uv__signal_first_handle(signum);
        handle != NULL && handle->signum == signum;