[ovs-dev] [threads 08/23] dirs: Make thread-safe.

[Ben Pfaff]

Signed-off-by: Ben Pfaff <blp at nicira.com>
---
 lib/dirs.c.in |   37 +++++++++++++++++++++++++++++--------
 1 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/lib/dirs.c.in b/lib/dirs.c.in
index 658a74b..85c49ee 100644
--- a/lib/dirs.c.in
+++ b/lib/dirs.c.in
@@ -1,6 +1,6 @@
 #line 2 "@srcdir@/lib/dirs.c.in"
 /*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,22 +18,25 @@
 #include <config.h>
 #include "dirs.h"
 #include <stdlib.h>
+#include "ovs-thread.h"
 #include "util.h"
 
 struct directory {
     const char *value;          /* Actual value; NULL if not yet determined. */
     const char *default_value;  /* Default value. */
     const char *var_name;       /* Environment variable to override default. */
+    struct ovsthread_once once; /* Ensures 'value' gets initialized once. */
 };
 
 static const char *
 get_dir(struct directory *d)
 {
-    if (!d->value) {
+    if (ovsthread_once_start(&d->once)) {
         d->value = getenv(d->var_name);
         if (!d->value || !d->value[0]) {
             d->value = d->default_value;
         }
+        ovsthread_once_done(&d->once);
     }
     return d->value;
 }
@@ -41,36 +44,50 @@ get_dir(struct directory *d)
 const char *
 ovs_sysconfdir(void)
 {
-    static struct directory d = { NULL, @sysconfdir@, "OVS_SYSCONFDIR" };
+    static struct directory d = {
+        NULL, @sysconfdir@, "OVS_SYSCONFDIR", OVSTHREAD_ONCE_INITIALIZER
+    };
+
     return get_dir(&d);
 }
 
 const char *
 ovs_pkgdatadir(void)
 {
-    static struct directory d = { NULL, @pkgdatadir@, "OVS_PKGDATADIR" };
+    static struct directory d = {
+        NULL, @pkgdatadir@, "OVS_PKGDATADIR", OVSTHREAD_ONCE_INITIALIZER
+    };
+
     return get_dir(&d);
 }
 
 const char *
 ovs_rundir(void)
 {
-    static struct directory d = { NULL, @RUNDIR@, "OVS_RUNDIR" };
+    static struct directory d = {
+        NULL, @RUNDIR@, "OVS_RUNDIR", OVSTHREAD_ONCE_INITIALIZER
+    };
+
     return get_dir(&d);
 }
 
 const char *
 ovs_logdir(void)
 {
-    static struct directory d = { NULL, @LOGDIR@, "OVS_LOGDIR" };
+    static struct directory d = {
+        NULL, @LOGDIR@, "OVS_LOGDIR", OVSTHREAD_ONCE_INITIALIZER
+    };
+
     return get_dir(&d);
 }
 
 const char *
 ovs_dbdir(void)
 {
+    static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER;
     static const char *dbdir;
-    if (!dbdir) {
+
+    if (ovsthread_once_start(&once)) {
         dbdir = getenv("OVS_DBDIR");
         if (!dbdir || !dbdir[0]) {
             char *sysconfdir = getenv("OVS_SYSCONFDIR");
@@ -79,6 +96,7 @@ ovs_dbdir(void)
                      ? xasprintf("%s/openvswitch", sysconfdir)
                      : @DBDIR@);
         }
+        ovsthread_once_done(&once);
     }
     return dbdir;
 }
@@ -86,6 +104,9 @@ ovs_dbdir(void)
 const char *
 ovs_bindir(void)
 {
-    static struct directory d = { NULL, @bindir@, "OVS_BINDIR" };
+    static struct directory d = {
+        NULL, @bindir@, "OVS_BINDIR", OVSTHREAD_ONCE_INITIALIZER
+    };
+
     return get_dir(&d);
 }
-- 
1.7.2.5