nsr: change leader-election code to use new etcd_lock

This is certainy much simpler (therefore easier to maintain) and should
be more robust as well.  Tested with both real and simulated versions of
the etcd API.

Change-Id: Ic67de7f87455fcd9aeb1354714698f9562b7e4a7
Signed-off-by: Jeff Darcy <jdarcy@redhat.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/xlators/cluster/nsr-server/src/etcd-sim.c b/xlators/cluster/nsr-server/src/etcd-sim.c
index 782b5f617..d0bea12c7 100644
--- a/xlators/cluster/nsr-server/src/etcd-sim.c
+++ b/xlators/cluster/nsr-server/src/etcd-sim.c
@@ -34,6 +34,8 @@
 #include <fcntl.h>
 #include <sys/file.h>
 
+#include "mem-pool.h"
+
 /*
  * Mock implementation of etcd
  * The etcd file is simulated in /tmp/<server-names>
@@ -244,3 +246,35 @@ etcd_watch (etcd_session this, char *pfx, char **keyp, char **valuep,
 {
 	return ETCD_WTF;
 }
+
+etcd_result
+etcd_lock (etcd_session session_as_void, char *key, unsigned int ttl,
+           char *index_in, char **index_out)
+{
+        char    *path;
+        int     fd;
+
+        if (!index_in) {
+                if (gf_asprintf(&path,"/var/tmp/%s",key) < 0) {
+                        return ETCD_WTF;
+                }
+                fd = open(path,O_RDWR|O_CREAT,0666);
+                GF_FREE(path);
+                if (fd < 0) {
+                        return ETCD_WTF;
+                }
+                if (flock(fd,LOCK_EX) < 0) {
+                        close(fd);
+                        return ETCD_WTF;
+                }
+                *index_out = strdup("42");
+        }
+
+        /*
+         * Yes, we leak an fd by not closing it here (and nobody else even
+         * knows about it).  That would be awful in any other context, but
+         * for test scripts it won't matter.
+         */
+        return ETCD_OK;
+}
+