clang: Add annotations for thread safety check.

[sliver-openvswitch.git] / lib / vlog.h

diff --git a/lib/vlog.h b/lib/vlog.h
index 3466d96..901b3d3 100644 (file)
--- a/lib/vlog.h
+++ b/lib/vlog.h
@@ -17,6 +17,15 @@
 #ifndef VLOG_H
 #define VLOG_H 1
 
+/* Logging.
+ *
+ *
+ * Thread-safety
+ * =============
+ *
+ * Fully thread safe.
+ */
+
 #include <limits.h>
 #include <stdarg.h>
 #include <stdbool.h>
@@ -79,8 +88,8 @@ struct vlog_module {
 #if USE_LINKER_SECTIONS
 #define VLOG_DEFINE_MODULE(MODULE)                                      \
         VLOG_DEFINE_MODULE__(MODULE)                                    \
-        extern struct vlog_module *vlog_module_ptr_##MODULE;            \
-        struct vlog_module *vlog_module_ptr_##MODULE                    \
+        extern struct vlog_module *const vlog_module_ptr_##MODULE;      \
+        struct vlog_module *const vlog_module_ptr_##MODULE              \
             __attribute__((section("vlog_modules"))) = &VLM_##MODULE
 #else
 #define VLOG_DEFINE_MODULE(MODULE) extern struct vlog_module VLM_##MODULE
@@ -95,7 +104,7 @@ struct vlog_rate_limit {
     time_t first_dropped;       /* Time first message was dropped. */
     time_t last_dropped;        /* Time of most recent message drop. */
     unsigned int n_dropped;     /* Number of messages dropped. */
-    pthread_mutex_t mutex;      /* Mutual exclusion for rate limit. */
+    struct ovs_mutex mutex;     /* Mutual exclusion for rate limit. */
 };
 
 /* Number of tokens to emit a message.  We add 'rate' tokens per millisecond,
@@ -110,7 +119,7 @@ struct vlog_rate_limit {
             0,                              /* first_dropped */         \
             0,                              /* last_dropped */          \
             0,                              /* n_dropped */             \
-            PTHREAD_ADAPTIVE_MUTEX_INITIALIZER /* mutex */              \
+            OVS_ADAPTIVE_MUTEX_INITIALIZER  /* mutex */                 \
         }
 
 /* Configuring how each module logs messages. */
@@ -231,13 +240,13 @@ void vlog_usage(void);
             vlog_rate_limit(THIS_MODULE, level__, RL, __VA_ARGS__); \
         }                                                           \
     } while (0)
-#define VLOG_ONCE(LEVEL, ...)                       \
-    do {                                            \
-        static bool already_logged;                 \
-        if (!already_logged) {                      \
-            already_logged = true;                  \
-            vlog(THIS_MODULE, LEVEL, __VA_ARGS__);  \
-        }                                           \
+#define VLOG_ONCE(LEVEL, ...)                                           \
+    do {                                                                \
+        static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER; \
+        if (ovsthread_once_start(&once)) {                              \
+            vlog(THIS_MODULE, LEVEL, __VA_ARGS__);                      \
+            ovsthread_once_done(&once);                                 \
+        }                                                               \
     } while (0)
 
 #define VLOG_DEFINE_MODULE__(MODULE)                                    \