bgpd: Zebra lib for Graceful Restart.

[mirror_frr.git] / lib / frr_pthread.h

diff --git a/lib/frr_pthread.h b/lib/frr_pthread.h
index 6096a50370e20ef55add3d0b390c6d663fd0501c..89519abae0165402010a2a9a54d8ed006be746dc 100644 (file)
--- a/lib/frr_pthread.h
+++ b/lib/frr_pthread.h
@@ -99,7 +99,7 @@ struct frr_pthread {
        char os_name[OS_THREAD_NAMELEN];
 };
 
-extern struct frr_pthread_attr frr_pthread_attr_default;
+extern const struct frr_pthread_attr frr_pthread_attr_default;
 
 /*
  * Initializes this module.
@@ -133,7 +133,7 @@ void frr_pthread_finish(void);
  * @param os_name - 16 characters (including '\0') thread name to set in os,
  * @return the created frr_pthread upon success, or NULL upon failure
  */
-struct frr_pthread *frr_pthread_new(struct frr_pthread_attr *attr,
+struct frr_pthread *frr_pthread_new(const struct frr_pthread_attr *attr,
                                    const char *name, const char *os_name);
 
 /*
@@ -215,6 +215,54 @@ void frr_pthread_stop_all(void);
 #define pthread_condattr_setclock(A, B)
 #endif
 
+/* mutex auto-lock/unlock */
+
+/* variant 1:
+ * (for short blocks, multiple mutexes supported)
+ * break & return can be used for aborting the block
+ *
+ * frr_with_mutex(&mtx, &mtx2) {
+ *    if (error)
+ *       break;
+ *    ...
+ * }
+ */
+#define _frr_with_mutex(mutex)                                                 \
+       *NAMECTR(_mtx_) __attribute__((                                        \
+               unused, cleanup(_frr_mtx_unlock))) = _frr_mtx_lock(mutex),     \
+       /* end */
+
+#define frr_with_mutex(...)                                                    \
+       for (pthread_mutex_t MACRO_REPEAT(_frr_with_mutex, ##__VA_ARGS__)      \
+            *_once = NULL; _once == NULL; _once = (void *)1)                  \
+       /* end */
+
+/* variant 2:
+ * (more suitable for long blocks, no extra indentation)
+ *
+ * frr_mutex_lock_autounlock(&mtx);
+ * ...
+ */
+#define frr_mutex_lock_autounlock(mutex)                                       \
+       pthread_mutex_t *NAMECTR(_mtx_)                                        \
+               __attribute__((unused, cleanup(_frr_mtx_unlock))) =            \
+                                   _frr_mtx_lock(mutex)                       \
+       /* end */
+
+static inline pthread_mutex_t *_frr_mtx_lock(pthread_mutex_t *mutex)
+{
+       pthread_mutex_lock(mutex);
+       return mutex;
+}
+
+static inline void _frr_mtx_unlock(pthread_mutex_t **mutex)
+{
+       if (!*mutex)
+               return;
+       pthread_mutex_unlock(*mutex);
+       *mutex = NULL;
+}
+
 #ifdef __cplusplus
 }
 #endif