X-Git-Url: https://git.liburcu.org/?a=blobdiff_plain;f=libust%2Ftracectl.c;h=463edb6b492897546a84cf3161c07c680a12eb10;hb=e005efaa25bb1c65019e147e5290733cf5e0c82d;hp=3b60975391abf72c155f9822a1b06fe3db68004d;hpb=0b362d6f999cbbe4b1a0d8cee2a9fb9a34422b7a;p=ust.git

diff --git a/libust/tracectl.c b/libust/tracectl.c
index 3b60975..463edb6 100644
--- 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);
@@ -553,14 +558,30 @@ static void listener_cleanup(void *ptr)
 	pthread_mutex_unlock(&listen_sock_mutex);
 }
 
-static void force_subbuf_switch()
+static int force_subbuf_switch(const char *trace_name)
 {
-	struct ust_buffer *buf;
+	struct ust_trace *trace;
+	int i, j, retval = 0;
+
+	ltt_lock_traces();
+	trace = _ltt_trace_find(trace_name);
+	if (!trace) {
+                retval = -ENODATA;
+                DBG("Cannot find trace. It was likely destroyed by the user.");
+                goto unlock_traces;
+        }
 
-	cds_list_for_each_entry(buf, &open_buffers_list,
-			    open_buffers_list) {
-		ltt_force_switch(buf, FORCE_FLUSH);
+	for (i = 0; i < trace->nr_channels; i++) {
+		for (j = 0; j < trace->channels[i].n_cpus; j++) {
+			ltt_force_switch(trace->channels[i].buf[j],
+					 FORCE_FLUSH);
+		}
 	}
+
+unlock_traces:
+	ltt_unlock_traces();
+
+	return retval;
 }
 
 /* Simple commands are those which need only respond with a return value. */
@@ -580,12 +601,6 @@ static int process_simple_client_cmd(int command, char *recv_buf)
 		return setenv("UST_DAEMON_SOCKET", sock_msg->field, 1);
 	}
 
-	case FORCE_SUBBUF_SWITCH:
-		/* FIXME: return codes? */
-		force_subbuf_switch();
-
-		break;
-
 	default:
 		return -EINVAL;
 	}
@@ -711,6 +726,15 @@ static int process_trace_cmd(int command, char *trace_name)
 			return result;
 		}
 		return 0;
+	case FORCE_SUBBUF_SWITCH:
+		DBG("force switch");
+
+		result = force_subbuf_switch(trace_name);
+		if (result < 0) {
+			ERR("force_subbuf_switch failed");
+			return result;
+		}
+		return 0;
 	}
 
 	return 0;
@@ -952,7 +976,7 @@ 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 +1002,7 @@ 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);
 
@@ -1043,6 +1067,7 @@ static void process_client_cmd(struct ustcomm_header *recv_header,
 	case START_TRACE:
 	case STOP_TRACE:
 	case DESTROY_TRACE:
+	case FORCE_SUBBUF_SWITCH:
 	{
 		struct ustcomm_single_field *trace_inf =
 			(struct ustcomm_single_field *)recv_buf;
@@ -1096,6 +1121,7 @@ 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 +1150,7 @@ void *listener_main(void *p)
 							   epoll_sock->fd);
 				}
 			}
-			pthread_mutex_unlock(&listener_thread_data_mutex);
+			pthread_cleanup_pop(1);	/* release listener mutex */
 		}
 	}
 
@@ -1691,6 +1717,7 @@ 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 +1738,20 @@ 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();
 }