X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=urcu.c;h=1a276ce33663439b7cb128e1ab6bea147faec1ed;hb=20bf310ac72677961e55867dd64d058f77e0d7e6;hp=7e79207be6a88eaaf6d2b74c0b16b4543368a6fd;hpb=41718ff94c4a07cb5f56d68084267798e471d1b1;p=userspace-rcu.git

diff --git a/urcu.c b/urcu.c
index 7e79207..1a276ce 100644
--- a/urcu.c
+++ b/urcu.c
@@ -1,3 +1,13 @@
+/*
+ * urcu.c
+ *
+ * Userspace RCU library
+ *
+ * Copyright February 2009 - Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
+ *
+ * Distributed under GPLv2
+ */
+
 #include <stdio.h>
 #include <pthread.h>
 #include <signal.h>
@@ -91,7 +101,7 @@ void wait_for_quiescent_state(int parity)
 		/*
 		 * BUSY-LOOP.
 		 */
-		while (*index->urcu_active_readers != 0)
+		while (index->urcu_active_readers[parity] != 0)
 			barrier();
 	}
 	/*
@@ -103,13 +113,35 @@ 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)
+{
+	rcu_write_lock();
+	switch_qparity();
+	switch_qparity();
+	rcu_write_unlock();
+}
+
 /*
  * Return old pointer, OK to free, no more reference exist.
  * Called under rcu_write_lock.
  */
 void *urcu_publish_content(void **ptr, void *new)
 {
-	int ret, prev_parity;
 	void *oldptr;
 
 	/*
@@ -124,19 +156,10 @@ void *urcu_publish_content(void **ptr, void *new)
 	 */
 	oldptr = *ptr;
 	*ptr = new;
-	wmb();		/* Write ptr before changing the qparity */
-	/* All threads should read qparity before ptr */
-	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();
+
 	return oldptr;
 }
 
@@ -175,7 +198,7 @@ void urcu_remove_reader(pthread_t id)
 
 	assert(reader_data != NULL);
 	for (index = reader_data; index < reader_data + num_readers; index++) {
-		if (index->tid == id) {
+		if (pthread_equal(index->tid, id)) {
 			memcpy(index, &reader_data[num_readers - 1],
 				sizeof(struct reader_data));
 			reader_data[num_readers - 1].tid = 0;
@@ -197,7 +220,6 @@ void urcu_register_thread(void)
 
 void urcu_unregister_thread(void)
 {
-	pthread_t self = pthread_self();
 	rcu_write_lock();
 	urcu_remove_reader(pthread_self());
 	rcu_write_unlock();