From c5bed3b13630bf1d194e821ab51113c37c70abe7 Mon Sep 17 00:00:00 2001
From: Adam Dickmeiss <adam@indexdata.dk>
Date: Sat, 24 May 2003 22:35:11 +0000
Subject: [PATCH] Zebra server checks for zebrasrv.pid and refuses to start if
 it is already locked by another (running) zebrasrv.

---
 CHANGELOG       |    3 +++
 index/kdump.c   |    5 ++++-
 index/zserver.c |   50 ++++++++++++++++++++++++++++++++++++--------------
 3 files changed, 43 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 8d05210..0188937 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,4 +1,7 @@
 
+Zebra server checks for zebrasrv.pid and refuses to start if it is already
+locked by another (running) zebrasrv.
+
 Fixed a bug with text being chunked in pieces for the grs.xml filter.
 
 --- 1.3.11 2003/04/25
diff --git a/index/kdump.c b/index/kdump.c
index 70662b9..46f4d8d 100644
--- a/index/kdump.c
+++ b/index/kdump.c
@@ -1,4 +1,4 @@
-/* $Id: kdump.c,v 1.22 2002-08-02 19:26:55 adam Exp $
+/* $Id: kdump.c,v 1.23 2003-05-24 22:35:11 adam Exp $
    Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002
    Index Data Aps
 
@@ -59,6 +59,9 @@ int key_file_decode (FILE *f)
         d = (d << 8) + (getc (f) & 0xff);
         d = (d << 8) + (getc (f) & 0xff);
         break;
+    default:
+        d = 0;
+        assert (0);
     }
     return d;
 }
diff --git a/index/zserver.c b/index/zserver.c
index eb89b09..af32209 100644
--- a/index/zserver.c
+++ b/index/zserver.c
@@ -1,4 +1,4 @@
-/* $Id: zserver.c,v 1.106 2003-05-20 13:52:41 adam Exp $
+/* $Id: zserver.c,v 1.107 2003-05-24 22:35:11 adam Exp $
    Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002
    Index Data Aps
 
@@ -20,22 +20,24 @@ Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 02111-1307, USA.
 */
 
-
-
 #include <stdio.h>
 #include <assert.h>
 #include <fcntl.h>
 #ifdef WIN32
 #include <io.h>
 #include <process.h>
+#include <sys/locking.h>
 #else
 #include <unistd.h>
 #endif
 
+#include <errno.h>
 #include <yaz/log.h>
 #include <yaz/ill.h>
 #include <yaz/yaz-util.h>
 
+#include <sys/types.h>
+
 #include "zserver.h"
 
 static int bend_sort (void *handle, bend_sort_rr *rr);
@@ -641,33 +643,53 @@ int bend_esrequest (void *handle, bend_esrequest_rr *rr)
 
 static void bend_start (struct statserv_options_block *sob)
 {
+    if (sob->handle)
+	zebra_stop((ZebraService) sob->handle);
+    sob->handle = zebra_start(sob->configname);
+    if (!sob->handle)
+    {
+	yaz_log (LOG_FATAL, "Failed to read config `%s'", sob->configname);
+	exit (1);
+    }
 #ifdef WIN32
     
 #else
     if (!sob->inetd) 
     {
+        struct flock area;
         char *pidfile = "zebrasrv.pid";
-        int fd = creat (pidfile, 0666);
+        int fd = open (pidfile, O_EXCL|O_WRONLY|O_CREAT, 0666);
         if (fd == -1)
-            yaz_log (LOG_WARN|LOG_ERRNO, "creat %s", pidfile);
+        {
+            if (errno != EEXIST)
+            {
+                yaz_log(LOG_FATAL|LOG_ERRNO, "lock file %s", pidfile);
+                exit(1);
+            }
+            fd = open(pidfile, O_RDWR, 0666);
+            if (fd == -1)
+            {
+                yaz_log(LOG_FATAL|LOG_ERRNO, "lock file %s", pidfile);
+                exit(1);
+            }
+        }
+        area.l_type = F_WRLCK;
+        area.l_whence = SEEK_SET;
+        area.l_len = area.l_start = 0L;
+        if (fcntl (fd, F_SETLK, &area) == -1)
+        {
+            yaz_log(LOG_ERRNO|LOG_FATAL, "Zebra server already running");
+            exit(1);
+        }
         else
         {
 	    char pidstr[30];
 	
 	    sprintf (pidstr, "%ld", (long) getpid ());
 	    write (fd, pidstr, strlen(pidstr));
-	    close (fd);
         }
     }
 #endif
-    if (sob->handle)
-	zebra_stop((ZebraService) sob->handle);
-    sob->handle = zebra_start(sob->configname);
-    if (!sob->handle)
-    {
-	yaz_log (LOG_FATAL, "Failed to read config `%s'", sob->configname);
-	exit (1);
-    }
 }
 
 static void bend_stop(struct statserv_options_block *sob)
-- 
1.7.10.4