X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=urcu-bp.c;h=280dd0dac4c5e00b9775e73f7b86f3a5507e5ca5;hb=6278a922c993b7e2a2ed4e0e3e75fb642271f3ba;hp=71474bcbcb6fe85494635c004bfdeb0d5f7a3aae;hpb=e038e286679be66f3d8096ea9c7224a1f282a9c3;p=userspace-rcu.git

diff --git a/urcu-bp.c b/urcu-bp.c
index 71474bc..280dd0d 100644
--- a/urcu-bp.c
+++ b/urcu-bp.c
@@ -79,8 +79,8 @@ void *mremap_wrapper(void *old_address, size_t old_size,
 }
 #endif
 
-/* Sleep delay in us */
-#define RCU_SLEEP_DELAY		1000
+/* Sleep delay in ms */
+#define RCU_SLEEP_DELAY_MS	10
 #define INIT_NR_THREADS		8
 #define ARENA_INIT_ALLOC		\
 	sizeof(struct registry_chunk)	\
@@ -91,10 +91,13 @@ void *mremap_wrapper(void *old_address, size_t old_size,
  */
 #define RCU_QS_ACTIVE_ATTEMPTS 100
 
+static
+int rcu_bp_refcount;
+
 static
 void __attribute__((constructor)) rcu_bp_init(void);
 static
-void __attribute__((destructor)) rcu_bp_exit(void);
+void __attribute__((destructor)) _rcu_bp_exit(void);
 
 static pthread_mutex_t rcu_gp_lock = PTHREAD_MUTEX_INITIALIZER;
 
@@ -105,7 +108,7 @@ static pthread_key_t urcu_bp_key;
 
 #ifdef DEBUG_YIELD
 unsigned int yield_active;
-DEFINE_URCU_TLS(unsigned int, rand_yield);
+__DEFINE_URCU_TLS_GLOBAL(unsigned int, rand_yield);
 #endif
 
 /*
@@ -120,7 +123,7 @@ long rcu_gp_ctr = RCU_GP_COUNT;
  * Pointer to registry elements. Written to only by each individual reader. Read
  * by both the reader and the writers.
  */
-DEFINE_URCU_TLS(struct rcu_reader *, rcu_reader);
+__DEFINE_URCU_TLS_GLOBAL(struct rcu_reader *, rcu_reader);
 
 static CDS_LIST_HEAD(registry);
 
@@ -171,7 +174,7 @@ static void mutex_unlock(pthread_mutex_t *mutex)
 void update_counter_and_wait(void)
 {
 	CDS_LIST_HEAD(qsreaders);
-	int wait_loops = 0;
+	unsigned int wait_loops = 0;
 	struct rcu_reader *index, *tmp;
 
 	/* Switch parity: 0 -> 1, 1 -> 0 */
@@ -195,7 +198,9 @@ void update_counter_and_wait(void)
 	 * Wait for each thread rcu_reader.ctr count to become 0.
 	 */
 	for (;;) {
-		wait_loops++;
+		if (wait_loops < RCU_QS_ACTIVE_ATTEMPTS)
+			wait_loops++;
+
 		cds_list_for_each_entry_safe(index, tmp, &registry, node) {
 			if (!rcu_old_gp_ongoing(&index->ctr))
 				cds_list_move(&index->node, &qsreaders);
@@ -204,8 +209,8 @@ void update_counter_and_wait(void)
 		if (cds_list_empty(&registry)) {
 			break;
 		} else {
-			if (wait_loops == RCU_QS_ACTIVE_ATTEMPTS)
-				usleep(RCU_SLEEP_DELAY);
+			if (wait_loops >= RCU_QS_ACTIVE_ATTEMPTS)
+				(void) poll(NULL, 0, RCU_SLEEP_DELAY_MS);
 			else
 				caa_cpu_relax();
 		}
@@ -429,11 +434,8 @@ struct registry_chunk *find_chunk(struct rcu_reader *rcu_reader_reg)
 
 /* Called with signals off and mutex locked */
 static
-void remove_thread(void)
+void remove_thread(struct rcu_reader *rcu_reader_reg)
 {
-	struct rcu_reader *rcu_reader_reg;
-
-	rcu_reader_reg = URCU_TLS(rcu_reader);
 	cleanup_thread(find_chunk(rcu_reader_reg), rcu_reader_reg);
 	URCU_TLS(rcu_reader) = NULL;
 }
@@ -474,7 +476,7 @@ end:
 
 /* Disable signals, take mutex, remove from registry */
 static
-void rcu_bp_unregister(void)
+void rcu_bp_unregister(struct rcu_reader *rcu_reader_reg)
 {
 	sigset_t newmask, oldmask;
 	int ret;
@@ -487,11 +489,12 @@ void rcu_bp_unregister(void)
 		abort();
 
 	mutex_lock(&rcu_gp_lock);
-	remove_thread();
+	remove_thread(rcu_reader_reg);
 	mutex_unlock(&rcu_gp_lock);
 	ret = pthread_sigmask(SIG_SETMASK, &oldmask, NULL);
 	if (ret)
 		abort();
+	_rcu_bp_exit();
 }
 
 /*
@@ -501,15 +504,14 @@ void rcu_bp_unregister(void)
 static
 void urcu_bp_thread_exit_notifier(void *rcu_key)
 {
-	assert(rcu_key == URCU_TLS(rcu_reader));
-	rcu_bp_unregister();
+	rcu_bp_unregister(rcu_key);
 }
 
 static
 void rcu_bp_init(void)
 {
 	mutex_lock(&init_lock);
-	if (!initialized) {
+	if (!rcu_bp_refcount++) {
 		int ret;
 
 		ret = pthread_key_create(&urcu_bp_key,
@@ -522,18 +524,32 @@ void rcu_bp_init(void)
 }
 
 static
-void rcu_bp_exit(void)
+void _rcu_bp_exit(void)
 {
-	struct registry_chunk *chunk, *tmp;
-	int ret;
+	mutex_lock(&init_lock);
+	if (!--rcu_bp_refcount) {
+		struct registry_chunk *chunk, *tmp;
+		int ret;
 
-	cds_list_for_each_entry_safe(chunk, tmp,
-			&registry_arena.chunk_list, node) {
-		munmap(chunk, chunk->data_len + sizeof(struct registry_chunk));
+		cds_list_for_each_entry_safe(chunk, tmp,
+				&registry_arena.chunk_list, node) {
+			munmap(chunk, chunk->data_len
+					+ sizeof(struct registry_chunk));
+		}
+		ret = pthread_key_delete(urcu_bp_key);
+		if (ret)
+			abort();
 	}
-	ret = pthread_key_delete(urcu_bp_key);
-	if (ret)
-		abort();
+	mutex_unlock(&init_lock);
+}
+
+/*
+ * Keep ABI compability within stable versions. This has never been
+ * exposed through a header, but needs to stay in the .so until the
+ * soname is bumped.
+ */
+void rcu_bp_exit(void)
+{
 }
 
 /*