Use liburcu-bp before/after fork (parent/child) callbacks

[ust.git] / libust / tracectl.c

diff --git a/libust/tracectl.c b/libust/tracectl.c
index 3b60975391abf72c155f9822a1b06fe3db68004d..830e777bb5114391e7525ca6713b138219125f38 100644 (file)
--- a/libust/tracectl.c
+++ b/libust/tracectl.c
@@ -543,6 +543,11 @@ unlock_traces:
        return retval;
 }
 
+static void release_listener_mutex(void *ptr)
+{
+       pthread_mutex_unlock(&listener_thread_data_mutex);
+}
+
 static void listener_cleanup(void *ptr)
 {
        pthread_mutex_lock(&listen_sock_mutex);
@@ -952,7 +957,7 @@ static void process_client_cmd(struct ustcomm_header *recv_header,
                print_markers(fp);
                fclose(fp);
 
-               reply_header->size = size;
+               reply_header->size = size + 1;  /* Include final \0 */
 
                result = ustcomm_send(sock, reply_header, ptr);
 
@@ -978,7 +983,7 @@ static void process_client_cmd(struct ustcomm_header *recv_header,
                print_trace_events(fp);
                fclose(fp);
 
-               reply_header->size = size;
+               reply_header->size = size + 1;  /* Include final \0 */
 
                result = ustcomm_send(sock, reply_header, ptr);
 
@@ -1096,6 +1101,7 @@ void *listener_main(void *p)
 
                for (i = 0; i < nfds; i++) {
                        pthread_mutex_lock(&listener_thread_data_mutex);
+                       pthread_cleanup_push(release_listener_mutex, NULL);
                        epoll_sock = (struct ustcomm_sock *)events[i].data.ptr;
                        if (epoll_sock == listen_sock) {
                                addr_size = sizeof(struct sockaddr);
@@ -1124,7 +1130,7 @@ void *listener_main(void *p)
                                                           epoll_sock->fd);
                                }
                        }
-                       pthread_mutex_unlock(&listener_thread_data_mutex);
+                       pthread_cleanup_pop(1); /* release listener mutex */
                }
        }
 
@@ -1691,6 +1697,7 @@ void ust_before_fork(ust_fork_info_t *fork_info)
         * Hold listen_sock_mutex to protect from listen_sock teardown.
         */
        pthread_mutex_lock(&listen_sock_mutex);
+       rcu_bp_before_fork();
 }
 
 /* Don't call this function directly in a traced program */
@@ -1711,24 +1718,20 @@ static void ust_after_fork_common(ust_fork_info_t *fork_info)
 
 void ust_after_fork_parent(ust_fork_info_t *fork_info)
 {
+       rcu_bp_after_fork_parent();
        /* Release mutexes and reenable signals */
        ust_after_fork_common(fork_info);
 }
 
 void ust_after_fork_child(ust_fork_info_t *fork_info)
 {
-       /* First sanitize the child */
+       /* Release urcu mutexes */
+       rcu_bp_after_fork_child();
+
+       /* Sanitize the child */
        ust_fork();
 
        /* Then release mutexes and reenable signals */
        ust_after_fork_common(fork_info);
-
-       /*
-        * Make sure we clean up the urcu-bp thread list in the child by running
-        * the garbage collection before any pthread_create can be called.
-        * Failure to do so could lead to a deadlock caused by reuse of a thread
-        * ID before urcu-bp garbage collection is performed.
-        */
-       synchronize_rcu();
 }