From: David Goulet <david.goulet@polymtl.ca>
Date: Tue, 8 Nov 2011 17:07:07 +0000 (-0500)
Subject: Add auto start UST trace support
X-Git-Tag: v2.0-pre15~147
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=36dc12ccfc6d008a6996a553c02c5823400c70b5

Add auto start UST trace support

Signed-off-by: David Goulet <david.goulet@polymtl.ca>
---

diff --git a/lttng-sessiond/main.c b/lttng-sessiond/main.c
index f13571ab3..40ad9add8 100644
--- a/lttng-sessiond/main.c
+++ b/lttng-sessiond/main.c
@@ -1718,6 +1718,7 @@ static int create_ust_session(struct ltt_session *session,
 		/* No ustctl for the global UST domain */
 		break;
 	default:
+		ERR("Unknown UST domain on create session %d", domain->type);
 		goto error;
 	}
 	session->ust_session = lus;
@@ -2433,6 +2434,9 @@ static int cmd_start_trace(struct ltt_session *session)
 		kernel_wait_quiescent(kernel_tracer_fd);
 	}
 
+	/* Flag session that trace should start automatically */
+	usess->start_trace = 1;
+
 	ret = ust_app_start_trace(usess);
 	if (ret < 0) {
 		ret = LTTCOMM_UST_START_FAIL;
diff --git a/lttng-sessiond/trace-ust.c b/lttng-sessiond/trace-ust.c
index 3e1055a8b..a1715f253 100644
--- a/lttng-sessiond/trace-ust.c
+++ b/lttng-sessiond/trace-ust.c
@@ -92,13 +92,14 @@ struct ltt_ust_session *trace_ust_create_session(char *path, unsigned int uid,
 	/* Allocate a new ltt ust session */
 	lus = malloc(sizeof(struct ltt_ust_session));
 	if (lus == NULL) {
-		perror("create ust session malloc");
+		PERROR("create ust session malloc");
 		goto error;
 	}
 
 	/* Init data structure */
 	lus->consumer_fds_sent = 0;
 	lus->uid = uid;
+	lus->start_trace = 0;
 
 	/* Alloc UST domain hash tables */
 	lus->domain_pid = hashtable_new(0);
diff --git a/lttng-sessiond/trace-ust.h b/lttng-sessiond/trace-ust.h
index 604024b18..f2ec7405f 100644
--- a/lttng-sessiond/trace-ust.h
+++ b/lttng-sessiond/trace-ust.h
@@ -100,6 +100,7 @@ struct ltt_ust_session {
 	int uid;   /* Unique identifier of session */
 	int consumer_fds_sent;
 	int consumer_fd;
+	int start_trace;
 	char pathname[PATH_MAX];
 	struct ltt_ust_domain_global domain_global;
 	/*
diff --git a/lttng-sessiond/ust-app.c b/lttng-sessiond/ust-app.c
index 21481b0f7..7eb454a5e 100644
--- a/lttng-sessiond/ust-app.c
+++ b/lttng-sessiond/ust-app.c
@@ -843,6 +843,7 @@ void ust_app_global_update(struct ltt_ust_session *usess, int sock)
 	struct lttng_ust_event ltt_uevent;
 	struct ltt_ust_channel *uchan;
 	struct lttng_ust_object_data *obj_event;
+	struct lttng_ust_channel_attr uattr;
 
 	DBG2("UST app global update for app sock %d for session uid %d", sock,
 			usess->uid);
@@ -957,11 +958,111 @@ next_event:
 			hashtable_get_next(ua_chan->events, &iter);
 		}
 
+		for (;;) {
+			struct lttng_ust_object_data *obj;
+			struct ltt_ust_stream *ustream;
+
+			ret = ustctl_create_stream(app->key.sock, ua_chan->obj, &obj);
+			if (ret < 0) {
+				/* Got all streams */
+				break;
+			}
+
+			ustream = zmalloc(sizeof(*ustream));
+			if (ustream == NULL) {
+				PERROR("zmalloc ust stream");
+				goto error;
+			}
+
+			ustream->obj = obj;
+			ustream->handle = ustream->obj->handle;
+			/* Order is important */
+			cds_list_add_tail(&ustream->list, &ua_chan->streams.head);
+
+			ret = snprintf(ustream->pathname, PATH_MAX, "%s/%s_%u",
+					uchan->pathname, uchan->name, ua_chan->streams.count++);
+			if (ret < 0) {
+				PERROR("asprintf UST create stream");
+				goto error;
+			}
+		}
+
 next_chan:
 		/* Next applications */
 		hashtable_get_next(ua_sess->channels, &iter);
 	}
 
+	if (ua_sess->metadata == NULL) {
+		/* Allocate UST metadata */
+		ua_sess->metadata = trace_ust_create_metadata(usess->pathname);
+		if (ua_sess->metadata == NULL) {
+			ERR("UST app session %d creating metadata failed",
+					ua_sess->handle);
+			goto error;
+		}
+
+		uattr.overwrite = ua_sess->metadata->attr.overwrite;
+		uattr.subbuf_size = ua_sess->metadata->attr.subbuf_size;
+		uattr.num_subbuf = ua_sess->metadata->attr.num_subbuf;
+		uattr.switch_timer_interval =
+			ua_sess->metadata->attr.switch_timer_interval;
+		uattr.read_timer_interval =
+			ua_sess->metadata->attr.read_timer_interval;
+		uattr.output = ua_sess->metadata->attr.output;
+
+		/* UST tracer metadata creation */
+		ret = ustctl_open_metadata(app->key.sock, ua_sess->handle, &uattr,
+				&ua_sess->metadata->obj);
+		if (ret < 0) {
+			ERR("UST app open metadata failed for app pid:%d",
+					app->key.pid);
+			goto error;
+		}
+
+		DBG2("UST metadata opened for app pid %d", app->key.pid);
+	}
+
+	/* Open UST metadata stream */
+	if (ua_sess->metadata->stream_obj == NULL) {
+		ret = ustctl_create_stream(app->key.sock, ua_sess->metadata->obj,
+				&ua_sess->metadata->stream_obj);
+		if (ret < 0) {
+			ERR("UST create metadata stream failed");
+			goto error;
+		}
+
+		ret = snprintf(ua_sess->metadata->pathname, PATH_MAX, "%s/%s",
+				usess->pathname, "metadata");
+		if (ret < 0) {
+			PERROR("asprintf UST create stream");
+			goto error;
+		}
+
+		DBG2("UST metadata stream object created for app pid %d",
+				app->key.pid);
+	}
+
+	if (usess->start_trace) {
+		/* Setup UST consumer socket and send fds to it */
+		ret = ust_consumer_send_session(usess->consumer_fd, ua_sess);
+		if (ret < 0) {
+			ERR("UST consumer send session failed");
+			goto error;
+		}
+
+		/* This start the UST tracing */
+		ret = ustctl_start_session(app->key.sock, ua_sess->handle);
+		if (ret < 0) {
+			ERR("Error starting tracing for app pid: %d", app->key.pid);
+			goto error;
+		}
+
+		/* Quiescent wait after starting trace */
+		ustctl_wait_quiescent(app->key.sock);
+
+		DBG2("UST trace started for app pid %d", app->key.pid);
+	}
+
 error:
 	rcu_read_unlock();
 	return;