From e637915823ab643216f44759a6cd495a05042d15 Mon Sep 17 00:00:00 2001
From: Isaac Connor <iconnor@pseudo.connortechnology.com>
Date: Fri, 4 Dec 2015 15:39:37 -0500
Subject: [PATCH] add a lock around the socket creating/deleting.

---
 src/zm_stream.cpp | 22 ++++++++++++++++++++++
 src/zm_stream.h   |  3 +++
 2 files changed, 25 insertions(+)

diff --git a/src/zm_stream.cpp b/src/zm_stream.cpp
index 30a420bb1..4e9a4da10 100644
--- a/src/zm_stream.cpp
+++ b/src/zm_stream.cpp
@@ -286,6 +286,23 @@ void StreamBase::openComms()
 {
     if ( connkey > 0 )
     {
+
+		snprintf( sock_path_lock, sizeof(sock_path_lock), "%s/zms-%06d.lock", config.path_socks, connkey);
+
+        lock_fd = open(sock_path_lock, O_CREAT|O_WRONLY, S_IRUSR | S_IWUSR);
+        if (lock_fd <= 0 || flock(lock_fd, LOCK_SH|LOCK_NB) != 0)
+        {
+            Error("Unable to lock sock lock file %s: %s", sock_path_lock, strerror(errno) );
+
+            close(lock_fd);
+            lock_fd = 0;
+        }
+        else
+        {
+            Debug( 1, "We have obtained a read lock on %s fd: %d", sock_path_lock, lock_fd);
+        }
+
+
         sd = socket( AF_UNIX, SOCK_DGRAM, 0 );
         if ( sd < 0 )
         {
@@ -321,6 +338,11 @@ void StreamBase::closeComms()
         {
             unlink( loc_sock_path );
         }
+		if (lock_fd > 0)
+		{
+			loc_sock_path[0] = '\0';
+			close(lock_fd); //close it rather than unlock it incase it got deleted.
+		}
     }
 }
 
diff --git a/src/zm_stream.h b/src/zm_stream.h
index ef442ab8e..9936688a8 100644
--- a/src/zm_stream.h
+++ b/src/zm_stream.h
@@ -78,6 +78,8 @@ protected:
     struct sockaddr_un loc_addr;
 	char rem_sock_path[PATH_MAX];
     struct sockaddr_un rem_addr;
+	char sock_path_lock[PATH_MAX];
+	int lock_fd;
 
 protected:
     bool paused;
@@ -127,6 +129,7 @@ public:
 
         connkey = 0;
         sd = -1;
+		lock_fd = 0;
         memset( &loc_sock_path, 0, sizeof(loc_sock_path) );
         memset( &loc_addr, 0, sizeof(loc_addr) );
         memset( &rem_sock_path, 0, sizeof(rem_sock_path) );