X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fagent-thread.c;h=575f6aee934a504ddb6248d4e87610d622d0959c;hp=b238656812c69390b2d7e16ee841d7830cd3ba03;hb=1f4962443f25c371e4b54e97f9eb867d67cbf88e;hpb=04fd2d2e705f7d9956f4cb8b18f6c43452913a16

diff --git a/src/bin/lttng-sessiond/agent-thread.c b/src/bin/lttng-sessiond/agent-thread.c
index b23865681..575f6aee9 100644
--- a/src/bin/lttng-sessiond/agent-thread.c
+++ b/src/bin/lttng-sessiond/agent-thread.c
@@ -31,6 +31,12 @@
 #include "lttng-sessiond.h"
 #include "session.h"
 #include "utils.h"
+#include "thread.h"
+
+struct thread_notifiers {
+	struct lttng_pipe *quit_pipe;
+	sem_t ready;
+};
 
 static int agent_tracing_enabled = -1;
 
@@ -59,6 +65,10 @@ static void update_agent_app(struct agent_app *app)
 
 	session_lock_list();
 	cds_list_for_each_entry_safe(session, stmp, &list->head, list) {
+		if (!session_get(session)) {
+			continue;
+		}
+
 		session_lock(session);
 		if (session->ust_session) {
 			struct agent *agt;
@@ -71,6 +81,7 @@ static void update_agent_app(struct agent_app *app)
 			rcu_read_unlock();
 		}
 		session_unlock(session);
+		session_put(session);
 	}
 	session_unlock_list();
 }
@@ -287,15 +298,33 @@ static int write_agent_port(uint16_t port)
 			config.agent_port_file_path.value);
 }
 
+static
+void mark_thread_as_ready(struct thread_notifiers *notifiers)
+{
+	DBG("Marking agent management thread as ready");
+	sem_post(&notifiers->ready);
+}
+
+static
+void wait_until_thread_is_ready(struct thread_notifiers *notifiers)
+{
+	DBG("Waiting for agent management thread to be ready");
+	sem_wait(&notifiers->ready);
+	DBG("Agent management thread is ready");
+}
+
 /*
  * This thread manage application notify communication.
  */
-void *agent_thread_manage_registration(void *data)
+static void *thread_agent_management(void *data)
 {
 	int i, ret, pollfd;
 	uint32_t revents, nb_fd;
 	struct lttng_poll_event events;
 	struct lttcomm_sock *reg_sock;
+	struct thread_notifiers *notifiers = data;
+	const int quit_pipe_read_fd = lttng_pipe_get_readfd(
+			notifiers->quit_pipe);
 
 	DBG("[agent-thread] Manage agent application registration.");
 
@@ -305,13 +334,18 @@ void *agent_thread_manage_registration(void *data)
 	/* Agent initialization call MUST be called before starting the thread. */
 	assert(agent_apps_ht_by_sock);
 
-	/* Create pollset with size 2, quit pipe and socket. */
-	ret = sessiond_set_thread_pollset(&events, 2);
+	/* Create pollset with size 2, quit pipe and registration socket. */
+	ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
 	if (ret < 0) {
-		sessiond_notify_ready();
 		goto error_poll_create;
 	}
 
+	ret = lttng_poll_add(&events, quit_pipe_read_fd,
+			LPOLLIN | LPOLLERR);
+	if (ret < 0) {
+		goto error_tcp_socket;
+	}
+
 	reg_sock = init_tcp_socket();
 	if (reg_sock) {
 		uint16_t port;
@@ -322,12 +356,12 @@ void *agent_thread_manage_registration(void *data)
 		if (ret) {
 			ERR("[agent-thread] Failed to create agent port file: agent tracing will be unavailable");
 			/* Don't prevent the launch of the sessiond on error. */
-			sessiond_notify_ready();
+			mark_thread_as_ready(notifiers);
 			goto error;
 		}
 	} else {
 		/* Don't prevent the launch of the sessiond on error. */
-		sessiond_notify_ready();
+		mark_thread_as_ready(notifiers);
 		goto error_tcp_socket;
 	}
 
@@ -336,7 +370,7 @@ void *agent_thread_manage_registration(void *data)
 	 * may start to query whether or not agent tracing is enabled.
 	 */
 	uatomic_set(&agent_tracing_enabled, 1);
-	sessiond_notify_ready();
+	mark_thread_as_ready(notifiers);
 
 	/* Add TCP socket to poll set. */
 	ret = lttng_poll_add(&events, reg_sock->fd,
@@ -370,14 +404,8 @@ restart:
 			revents = LTTNG_POLL_GETEV(&events, i);
 			pollfd = LTTNG_POLL_GETFD(&events, i);
 
-			if (!revents) {
-				/* No activity for this FD (poll implementation). */
-				continue;
-			}
-
 			/* Thread quit pipe has been closed. Killing thread. */
-			ret = sessiond_check_thread_quit_pipe(pollfd, revents);
-			if (ret) {
+			if (pollfd == quit_pipe_read_fd) {
 				goto exit;
 			}
 
@@ -441,9 +469,57 @@ error_tcp_socket:
 	lttng_poll_clean(&events);
 error_poll_create:
 	uatomic_set(&agent_tracing_enabled, 0);
-	DBG("[agent-thread] is cleaning up and stopping.");
-
+	DBG("[agent-thread] Cleaning up and stopping.");
 	rcu_thread_offline();
 	rcu_unregister_thread();
 	return NULL;
 }
+
+static bool shutdown_agent_management_thread(void *data)
+{
+	struct thread_notifiers *notifiers = data;
+	const int write_fd = lttng_pipe_get_writefd(notifiers->quit_pipe);
+
+	return notify_thread_pipe(write_fd) == 1;
+}
+
+static void cleanup_agent_management_thread(void *data)
+{
+	struct thread_notifiers *notifiers = data;
+
+	lttng_pipe_destroy(notifiers->quit_pipe);
+	sem_destroy(&notifiers->ready);
+	free(notifiers);
+}
+
+bool launch_agent_management_thread(void)
+{
+	struct thread_notifiers *notifiers;
+	struct lttng_thread *thread;
+
+	notifiers = zmalloc(sizeof(*notifiers));
+	if (!notifiers) {
+		goto error_alloc;
+	}
+
+	sem_init(&notifiers->ready, 0, 0);
+	notifiers->quit_pipe = lttng_pipe_open(FD_CLOEXEC);
+	if (!notifiers->quit_pipe) {
+		goto error;
+	}
+	thread = lttng_thread_create("Agent management",
+			thread_agent_management,
+			shutdown_agent_management_thread,
+			cleanup_agent_management_thread,
+			notifiers);
+	if (!thread) {
+		goto error;
+	}
+	wait_until_thread_is_ready(notifiers);
+	lttng_thread_put(thread);
+	return true;
+error:
+	cleanup_agent_management_thread(notifiers);
+error_alloc:
+	return false;
+}