X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fagent-thread.c;h=189e3ba6b671d38db58b19b6c998530ebcc3fae0;hb=2df44f1e14d94e6506192635d7aff0e87a3462f9;hp=d1bb122c171d9158b343f504497e5fba2fe64382;hpb=6a4e403927ffef4cae8726064dcf53c463eb128c;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/agent-thread.c b/src/bin/lttng-sessiond/agent-thread.c
index d1bb122c1..189e3ba6b 100644
--- a/src/bin/lttng-sessiond/agent-thread.c
+++ b/src/bin/lttng-sessiond/agent-thread.c
@@ -15,7 +15,6 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <assert.h>
 
@@ -33,6 +32,8 @@
 #include "session.h"
 #include "utils.h"
 
+static int agent_tracing_enabled = -1;
+
 /*
  * Note that there is not port here. It's set after this URI is parsed so we
  * can let the user define a custom one. However, localhost is ALWAYS the
@@ -224,6 +225,15 @@ error:
 	return ret;
 }
 
+bool agent_tracing_is_enabled(void)
+{
+	int enabled;
+
+	enabled = uatomic_read(&agent_tracing_enabled);
+	assert(enabled != -1);
+	return enabled == 1;
+}
+
 /*
  * This thread manage application notify communication.
  */
@@ -245,10 +255,18 @@ void *agent_thread_manage_registration(void *data)
 	/* Create pollset with size 2, quit pipe and socket. */
 	ret = sessiond_set_thread_pollset(&events, 2);
 	if (ret < 0) {
+		sessiond_notify_ready();
 		goto error_poll_create;
 	}
 
 	reg_sock = init_tcp_socket();
+	uatomic_set(&agent_tracing_enabled, !!reg_sock);
+
+	/*
+	 * Signal that the agent thread is ready. The command thread
+	 * may start to query whether or not agent tracing is enabled.
+	 */
+	sessiond_notify_ready();
 	if (!reg_sock) {
 		goto error_tcp_socket;
 	}
@@ -296,35 +314,22 @@ restart:
 				goto exit;
 			}
 
-			/*
-			 * Check first if this is a POLLERR since POLLIN is also included
-			 * in an error value thus checking first.
-			 */
-			if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
-				/* Removing from the poll set */
-				ret = lttng_poll_del(&events, pollfd);
-				if (ret < 0) {
-					goto error;
-				}
-
-				agent_destroy_app_by_sock(pollfd);
-			} else if (revents & (LPOLLIN)) {
+			if (revents & LPOLLIN) {
 				int new_fd;
 				struct agent_app *app = NULL;
 
-				/* Pollin event of agent app socket should NEVER happen. */
 				assert(pollfd == reg_sock->fd);
-
 				new_fd = handle_registration(reg_sock, &app);
 				if (new_fd < 0) {
-					WARN("[agent-thread] agent registration failed. Ignoring.");
-					/* Somehow the communication failed. Just continue. */
 					continue;
 				}
 				/* Should not have a NULL app on success. */
 				assert(app);
 
-				/* Only add poll error event to only detect shutdown. */
+				/*
+				 * Since this is a command socket (write then read),
+				 * only add poll error event to only detect shutdown.
+				 */
 				ret = lttng_poll_add(&events, new_fd,
 						LPOLLERR | LPOLLHUP | LPOLLRDHUP);
 				if (ret < 0) {
@@ -336,15 +341,32 @@ restart:
 				update_agent_app(app);
 
 				/* On failure, the poll will detect it and clean it up. */
-				(void) agent_send_registration_done(app);
+				ret = agent_send_registration_done(app);
+				if (ret < 0) {
+					/* Removing from the poll set */
+					ret = lttng_poll_del(&events, new_fd);
+					if (ret < 0) {
+						goto error;
+					}
+					agent_destroy_app_by_sock(new_fd);
+					continue;
+				}
+			} else if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+				/* Removing from the poll set */
+				ret = lttng_poll_del(&events, pollfd);
+				if (ret < 0) {
+					goto error;
+				}
+				agent_destroy_app_by_sock(pollfd);
 			} else {
-				ERR("Unknown poll events %u for sock %d", revents, pollfd);
-				continue;
+				ERR("Unexpected poll events %u for sock %d", revents, pollfd);
+				goto error;
 			}
 		}
 	}
 
 exit:
+	uatomic_set(&agent_tracing_enabled, 0);
 	/* Whatever happens, try to delete it and exit. */
 	(void) lttng_poll_del(&events, reg_sock->fd);
 error: