[ovs-dev] [threads 07/23] xenserver: Make thread-safe.
Ben Pfaff
blp at nicira.com
Thu Jul 18 23:15:20 UTC 2013
Signed-off-by: Ben Pfaff <blp at nicira.com>
---
vswitchd/xenserver.c | 23 +++++++++++------------
1 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/vswitchd/xenserver.c b/vswitchd/xenserver.c
index 1f26e0d..bc57f0e 100644
--- a/vswitchd/xenserver.c
+++ b/vswitchd/xenserver.c
@@ -17,6 +17,7 @@
#include "xenserver.h"
#include <ctype.h>
#include <errno.h>
+#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
@@ -26,7 +27,11 @@
VLOG_DEFINE_THIS_MODULE(xenserver);
-static char *
+/* If running on a XenServer, the XenServer host UUID as a 36-character string,
+ * otherwise null. */
+static char *host_uuid;
+
+static void
read_host_uuid(void)
{
static const char filename[] = "/etc/xensource-inventory";
@@ -40,7 +45,7 @@ read_host_uuid(void)
} else {
VLOG_INFO("%s: open: %s", filename, ovs_strerror(errno));
}
- return NULL;
+ return;
}
while (fgets(line, sizeof line, file)) {
@@ -53,27 +58,21 @@ read_host_uuid(void)
if (strlen(line) == leader_len + uuid_len + trailer_len
&& !memcmp(line, leader, leader_len)
&& !memcmp(line + leader_len + uuid_len, trailer, trailer_len)) {
- char *host_uuid = xmemdup0(line + leader_len, uuid_len);
+ host_uuid = xmemdup0(line + leader_len, uuid_len);
VLOG_INFO("running on XenServer, host-uuid %s", host_uuid);
fclose(file);
- return host_uuid;
+ return;
}
}
fclose(file);
VLOG_ERR("%s: INSTALLATION_UUID not found", filename);
- return NULL;
}
const char *
xenserver_get_host_uuid(void)
{
- static char *host_uuid;
- static bool inited;
-
- if (!inited) {
- host_uuid = read_host_uuid();
- inited = true;
- }
+ static pthread_once_t once = PTHREAD_ONCE_INIT;
+ pthread_once(&once, read_host_uuid);
return host_uuid;
}
--
1.7.2.5
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