Version 0.7.11
[userspace-rcu.git] / urcu-bp.c
index 0963dd05096d8ac5bc7f3c93520f064f75592a80..1386dfc8fdfb82a533aface955c79c6f0b318daf 100644 (file)
--- 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)   \
@@ -91,6 +91,9 @@ 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
@@ -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,
@@ -524,16 +526,21 @@ void rcu_bp_init(void)
 static
 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);
 }
 
 /*
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