Change API

[urcu.git] / urcu.c

diff --git a/urcu.c b/urcu.c
index e401d8dc75d34bf04d2e62da56df3cc08f0d470d..08fb75dd0feae13421647f7d84615bee6d88654f 100644 (file)
--- a/urcu.c
+++ b/urcu.c
@@ -36,7 +36,7 @@ static struct reader_data *reader_data;
 static int num_readers, alloc_readers;
 static int sig_done;
 
-void rcu_write_lock(void)
+void internal_urcu_lock(void)
 {
        int ret;
        ret = pthread_mutex_lock(&urcu_mutex);
@@ -46,7 +46,7 @@ void rcu_write_lock(void)
        }
 }
 
-void rcu_write_unlock(void)
+void internal_urcu_unlock(void)
 {
        int ret;
 
@@ -113,15 +113,38 @@ void wait_for_quiescent_state(int parity)
        force_mb_all_threads();
 }
 
+static void switch_qparity(void)
+{
+       int prev_parity;
+
+       /* All threads should read qparity before accessing data structure. */
+       /* Write ptr before changing the qparity */
+       force_mb_all_threads();
+       prev_parity = switch_next_urcu_qparity();
+
+       /*
+        * Wait for previous parity to be empty of readers.
+        */
+       wait_for_quiescent_state(prev_parity);
+}
+
+void synchronize_rcu(void)
+{
+       internal_urcu_lock();
+       switch_qparity();
+       switch_qparity();
+       internal_urcu_lock();
+}
+
 /*
  * Return old pointer, OK to free, no more reference exist.
  * Called under rcu_write_lock.
  */
 void *urcu_publish_content(void **ptr, void *new)
 {
-       int prev_parity;
        void *oldptr;
 
+       internal_urcu_lock();
        /*
         * We can publish the new pointer before we change the current qparity.
         * Readers seeing the new pointer while being in the previous qparity
@@ -134,19 +157,11 @@ void *urcu_publish_content(void **ptr, void *new)
         */
        oldptr = *ptr;
        *ptr = new;
-       /* All threads should read qparity before ptr */
-       /* Write ptr before changing the qparity */
-       force_mb_all_threads();
-       prev_parity = switch_next_urcu_qparity();
 
-       /*
-        * Wait for previous parity to be empty of readers.
-        */
-       wait_for_quiescent_state(prev_parity);
-       /*
-        * Deleting old data is ok !
-        */
-       
+       switch_qparity();
+       switch_qparity();
+       internal_urcu_unlock();
+
        return oldptr;
 }
 
@@ -200,16 +215,16 @@ void urcu_remove_reader(pthread_t id)
 
 void urcu_register_thread(void)
 {
-       rcu_write_lock();
+       internal_urcu_lock();
        urcu_add_reader(pthread_self());
-       rcu_write_unlock();
+       internal_urcu_unlock();
 }
 
 void urcu_unregister_thread(void)
 {
-       rcu_write_lock();
+       internal_urcu_lock();
        urcu_remove_reader(pthread_self());
-       rcu_write_unlock();
+       internal_urcu_unlock();
 }
 
 void sigurcu_handler(int signo, siginfo_t *siginfo, void *context)