From 6a75f3258b2ed499397d0964dd205e6764d3857e Mon Sep 17 00:00:00 2001
From: Dirk Zimoch <dirk.zimoch@psi.ch>
Date: Wed, 28 Feb 2018 16:53:35 +0100
Subject: [PATCH] add EPICS_ALLOW_MULTIPLE_IOCS to prevent starting more than
 one IOC on one machine

---
 src/rsrv/caservertask.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/src/rsrv/caservertask.c b/src/rsrv/caservertask.c
index 71c35ec1b..8a9cf494e 100644
--- a/src/rsrv/caservertask.c
+++ b/src/rsrv/caservertask.c
@@ -34,6 +34,8 @@
 #include "dbEvent.h"
 #include "dbCommon.h"
 #include "epicsStdioRedirect.h"
+#include "epicsExit.h"
+#include "epicsString.h"
 
 #define epicsExportSharedSymbols
 #include "rsrv.h"
@@ -108,6 +110,15 @@ static void req_server (void *pParm)
     if ( status < 0 ) {
         if ( SOCKERRNO == SOCK_EADDRINUSE ||
              SOCKERRNO == SOCK_EACCES ) {
+#ifndef vxWorks
+            const char* multiple_iocs = getenv("EPICS_ALLOW_MULTIPLE_IOCS");
+            if (multiple_iocs && epicsStrCaseCmp(multiple_iocs, "NO") == 0)
+            {
+                errlogPrintf ( "CAS: Default server port %d unavailable.\n" ,ca_server_port);
+                errlogPrintf ( "CAS: Probably already running an IOC on this computer.\n");
+                epicsExit(1);
+            }
+#endif
             /*
              * enable assignment of a default port
              * (so the getsockname() call below will