X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fagent.c;h=def13707bdf52fd40149dc0d9705393b4652b618;hp=33559c89a9423ea13b322d90c5db9995269d9f21;hb=a0ba721c2d0dd5eccf94bf210a85dcd255385c59;hpb=19a97244f801504a7985eee1b4ecca933f660b4a

diff --git a/src/bin/lttng-sessiond/agent.c b/src/bin/lttng-sessiond/agent.c
index 33559c89a..def13707b 100644
--- a/src/bin/lttng-sessiond/agent.c
+++ b/src/bin/lttng-sessiond/agent.c
@@ -15,7 +15,6 @@
  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#define _GNU_SOURCE
 #define _LGPL_SOURCE
 #include <assert.h>
 #include <urcu/uatomic.h>
@@ -361,7 +360,9 @@ error:
 static int enable_event(struct agent_app *app, struct agent_event *event)
 {
 	int ret;
+	char *bytes_to_send;
 	uint64_t data_size;
+	size_t filter_expression_length;
 	uint32_t reply_ret_code;
 	struct lttcomm_agent_enable msg;
 	struct lttcomm_agent_generic_reply reply;
@@ -373,7 +374,16 @@ static int enable_event(struct agent_app *app, struct agent_event *event)
 	DBG2("Agent enabling event %s for app pid: %d and socket %d", event->name,
 			app->pid, app->sock->fd);
 
-	data_size = sizeof(msg);
+	/*
+	 * Calculate the payload's size, which is the fixed-size struct followed
+	 * by the variable-length filter expression (+1 for the ending \0).
+	 */
+	if (!event->filter_expression) {
+		filter_expression_length = 0;
+	} else {
+		filter_expression_length = strlen(event->filter_expression) + 1;
+	}
+	data_size = sizeof(msg) + filter_expression_length;
 
 	ret = send_header(app->sock, data_size, AGENT_CMD_ENABLE, 0);
 	if (ret < 0) {
@@ -384,7 +394,22 @@ static int enable_event(struct agent_app *app, struct agent_event *event)
 	msg.loglevel_value = event->loglevel_value;
 	msg.loglevel_type = event->loglevel_type;
 	strncpy(msg.name, event->name, sizeof(msg.name));
-	ret = send_payload(app->sock, &msg, sizeof(msg));
+	msg.filter_expression_length = filter_expression_length;
+
+	bytes_to_send = zmalloc(data_size);
+	if (!bytes_to_send) {
+		ret = LTTNG_ERR_NOMEM;
+		goto error;
+	}
+
+	memcpy(bytes_to_send, &msg, sizeof(msg));
+	if (filter_expression_length > 0) {
+		memcpy(bytes_to_send + sizeof(msg), event->filter_expression,
+				filter_expression_length);
+	}
+
+	ret = send_payload(app->sock, bytes_to_send, data_size);
+	free(bytes_to_send);
 	if (ret < 0) {
 		goto error_io;
 	}
@@ -874,46 +899,54 @@ void agent_add_event(struct agent_event *event, struct agent *agt)
 }
 
 /*
- * Find a agent event in the given agent using name.
+ * Find multiple agent events sharing the given name.
  *
- * RCU read side lock MUST be acquired.
+ * RCU read side lock MUST be acquired. It must be held for the
+ * duration of the iteration.
  *
- * Return object if found else NULL.
+ * Sets the given iterator.
  */
-struct agent_event *agent_find_event_by_name(const char *name,
-		struct agent *agt)
+void agent_find_events_by_name(const char *name, struct agent *agt,
+		struct lttng_ht_iter* iter)
 {
-	struct lttng_ht_node_str *node;
-	struct lttng_ht_iter iter;
 	struct lttng_ht *ht;
 	struct agent_ht_key key;
 
 	assert(name);
 	assert(agt);
 	assert(agt->events);
+	assert(iter);
 
 	ht = agt->events;
 	key.name = name;
 
 	cds_lfht_lookup(ht->ht, ht->hash_fct((void *) name, lttng_ht_seed),
-			ht_match_event_by_name, &key, &iter.iter);
-	node = lttng_ht_iter_get_node_str(&iter);
-	if (node == NULL) {
-		goto error;
-	}
+			ht_match_event_by_name, &key, &iter->iter);
+}
 
-	DBG3("Agent event found %s by name.", name);
-	return caa_container_of(node, struct agent_event, node);
+/*
+ * Get the next agent event duplicate by name. This should be called
+ * after a call to agent_find_events_by_name() to iterate on events.
+ *
+ * The RCU read lock must be held during the iteration and for as long
+ * as the object the iterator points to remains in use.
+ */
+void agent_event_next_duplicate(const char *name,
+		struct agent *agt, struct lttng_ht_iter* iter)
+{
+	struct agent_ht_key key;
 
-error:
-	DBG3("Agent NOT found by name %s.", name);
-	return NULL;
+	key.name = name;
+
+	cds_lfht_next_duplicate(agt->events->ht, ht_match_event_by_name,
+		&key, &iter->iter);
 }
 
 /*
  * Find a agent event in the given agent using name and loglevel.
  *
- * RCU read side lock MUST be acquired.
+ * RCU read side lock MUST be acquired. It must be kept for as long as
+ * the returned agent_event is used.
  *
  * Return object if found else NULL.
  */