clang: Add annotations for thread safety check.

This commit adds annotations for thread safety check. And the
check can be conducted by using -Wthread-safety flag in clang.

Co-authored-by: Alex Wang <alexw@nicira.com>
Signed-off-by: Alex Wang <alexw@nicira.com>
Signed-off-by: Ethan Jackson <ethan@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

1 files changed, 19 insertions, 9 deletions

diff --git a/lib/command-line.c b/lib/command-line.c
index 39b26daee..805e51b35 100644
--- a/lib/command-line.c
+++ b/lib/command-line.c
@@ -94,10 +94,16 @@ run_command(int argc, char *argv[], const struct command commands[])
 /* Process title. */
 
 #ifdef LINUX_DATAPATH
-static char *argv_start;       /* Start of command-line arguments in memory. */
-static size_t argv_size;       /* Number of bytes of command-line arguments. */
-static char *saved_proctitle;  /* Saved command-line arguments. */
-static pthread_mutex_t proctitle_mutex = PTHREAD_MUTEX_INITIALIZER;
+static struct ovs_mutex proctitle_mutex = OVS_MUTEX_INITIALIZER;
+
+/* Start of command-line arguments in memory. */
+static char *argv_start OVS_GUARDED_BY(proctitle_mutex);
+
+/* Number of bytes of command-line arguments. */
+static size_t argv_size OVS_GUARDED_BY(proctitle_mutex);
+
+/* Saved command-line arguments. */
+static char *saved_proctitle OVS_GUARDED_BY(proctitle_mutex);
 
 /* Prepares the process so that proctitle_set() can later succeed.
  *
@@ -118,6 +124,7 @@ proctitle_init(int argc, char **argv)
         return;
     }
 
+    ovs_mutex_lock(&proctitle_mutex);
     /* Specialized version of first loop iteration below. */
     argv_start = argv[0];
     argv_size = strlen(argv[0]) + 1;
@@ -141,6 +148,7 @@ proctitle_init(int argc, char **argv)
         /* Copy out the old argument so we can reuse the space. */
         argv[i] = xstrdup(argv[i]);
     }
+    ovs_mutex_unlock(&proctitle_mutex);
 }
 
 /* Changes the name of the process, as shown by "ps", to the program name
@@ -151,11 +159,11 @@ proctitle_set(const char *format, ...)
     va_list args;
     int n;
 
+    ovs_mutex_lock(&proctitle_mutex);
     if (!argv_start || argv_size < 8) {
-        return;
+        goto out;
     }
 
-    xpthread_mutex_lock(&proctitle_mutex);
     if (!saved_proctitle) {
         saved_proctitle = xmemdup(argv_start, argv_size);
     }
@@ -174,20 +182,22 @@ proctitle_set(const char *format, ...)
         memset(&argv_start[n], '\0', argv_size - n);
     }
     va_end(args);
-    xpthread_mutex_unlock(&proctitle_mutex);
+
+out:
+    ovs_mutex_unlock(&proctitle_mutex);
 }
 
 /* Restores the process's original command line, as seen by "ps". */
 void
 proctitle_restore(void)
 {
-    xpthread_mutex_lock(&proctitle_mutex);
+    ovs_mutex_lock(&proctitle_mutex);
     if (saved_proctitle) {
         memcpy(argv_start, saved_proctitle, argv_size);
         free(saved_proctitle);
         saved_proctitle = NULL;
     }
-    xpthread_mutex_unlock(&proctitle_mutex);
+    ovs_mutex_unlock(&proctitle_mutex);
 }
 #else  /* !LINUX_DATAPATH*/
 /* Stubs that don't do anything on non-Linux systems. */