From: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Date: Wed, 9 Sep 2020 21:16:53 +0000 (-0400)
Subject: trigger: generate and add tracer token on registration
X-Git-Tag: v2.13.0-rc1~427
X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=commitdiff_plain;h=e6887944f09a8985efb521ea638b4dfe557ff4ed;hp=34f87583034e1aa9d65ce5d35b09bd5e8cfba875

trigger: generate and add tracer token on registration

Assign a unique tracer token to a trigger.

This token will be used as the unique id that will be communicated back
to the sessiond by the tracers for tracer notification.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
Change-Id: I2033dcaa4c5536b29dd4d7c57933e1aa686082cd
---

diff --git a/include/lttng/trigger/trigger-internal.h b/include/lttng/trigger/trigger-internal.h
index 20b1ff33a..df69f3d11 100644
--- a/include/lttng/trigger/trigger-internal.h
+++ b/include/lttng/trigger/trigger-internal.h
@@ -29,6 +29,12 @@ struct lttng_trigger {
 	char *name;
 	/* For now only the uid portion of the credentials is used. */
 	struct lttng_credentials creds;
+	/*
+	 * Internal use only.
+	 * The unique token passed to the tracer to identify an event-rule
+	 * notification.
+	 */
+	LTTNG_OPTIONAL(uint64_t) tracer_token;
 };
 
 struct lttng_trigger_comm {
@@ -71,6 +77,13 @@ LTTNG_HIDDEN
 int lttng_trigger_assign_name(
 		struct lttng_trigger *dst, const struct lttng_trigger *src);
 
+LTTNG_HIDDEN
+void lttng_trigger_set_tracer_token(
+		struct lttng_trigger *trigger, uint64_t token);
+
+LTTNG_HIDDEN
+uint64_t lttng_trigger_get_tracer_token(const struct lttng_trigger *trigger);
+
 LTTNG_HIDDEN
 int lttng_trigger_generate_name(struct lttng_trigger *trigger,
 		uint64_t unique_id);
diff --git a/src/bin/lttng-sessiond/notification-thread-events.c b/src/bin/lttng-sessiond/notification-thread-events.c
index b47a79528..398ddc389 100644
--- a/src/bin/lttng-sessiond/notification-thread-events.c
+++ b/src/bin/lttng-sessiond/notification-thread-events.c
@@ -2232,9 +2232,14 @@ int handle_notification_thread_command_register_trigger(
 	uid_t object_uid;
 	gid_t object_gid;
 	enum action_executor_status executor_status;
+	const uint64_t trigger_tracer_token =
+			state->trigger_id.next_tracer_token++;
 
 	rcu_read_lock();
 
+	/* Set the trigger's tracer token. */
+	lttng_trigger_set_tracer_token(trigger, trigger_tracer_token);
+
 	if (lttng_trigger_get_name(trigger, &trigger_name) ==
 			LTTNG_TRIGGER_STATUS_UNSET) {
 		const enum lttng_error_code ret_code = generate_trigger_name(
@@ -2473,6 +2478,8 @@ int handle_notification_thread_command_register_trigger(
 
 end:
 	*cmd_result = LTTNG_OK;
+	DBG("Registered trigger: name = `%s`, tracer token = %" PRIu64,
+			trigger_name, trigger_tracer_token);
 
 error_put_client_list:
 	notification_client_list_put(client_list);
diff --git a/src/bin/lttng-sessiond/notification-thread.c b/src/bin/lttng-sessiond/notification-thread.c
index 0c2d0d294..9b2cd5b96 100644
--- a/src/bin/lttng-sessiond/notification-thread.c
+++ b/src/bin/lttng-sessiond/notification-thread.c
@@ -407,6 +407,7 @@ int init_thread_state(struct notification_thread_handle *handle,
 
 	memset(state, 0, sizeof(*state));
 	state->notification_channel_socket = -1;
+	state->trigger_id.next_tracer_token = 1;
 	lttng_poll_init(&state->events);
 
 	ret = notification_channel_socket_create();
diff --git a/src/bin/lttng-sessiond/notification-thread.h b/src/bin/lttng-sessiond/notification-thread.h
index 4e1ca4b80..c80bb691d 100644
--- a/src/bin/lttng-sessiond/notification-thread.h
+++ b/src/bin/lttng-sessiond/notification-thread.h
@@ -219,6 +219,7 @@ struct notification_thread_state {
 	struct cds_lfht *triggers_ht;
 	struct cds_lfht *triggers_by_name_uid_ht;
 	struct {
+		uint64_t next_tracer_token;
 		uint64_t name_offset;
 	} trigger_id;
 	notification_client_id next_notification_client_id;
diff --git a/src/common/trigger.c b/src/common/trigger.c
index af0c5fa34..f77a32129 100644
--- a/src/common/trigger.c
+++ b/src/common/trigger.c
@@ -395,6 +395,22 @@ end:
 	return ret;
 }
 
+LTTNG_HIDDEN
+void lttng_trigger_set_tracer_token(struct lttng_trigger *trigger,
+		uint64_t token)
+{
+	assert(trigger);
+	LTTNG_OPTIONAL_SET(&trigger->tracer_token, token);
+}
+
+LTTNG_HIDDEN
+uint64_t lttng_trigger_get_tracer_token(const struct lttng_trigger *trigger)
+{
+	assert(trigger);
+
+	return LTTNG_OPTIONAL_GET(trigger->tracer_token);
+}
+
 LTTNG_HIDDEN
 int lttng_trigger_generate_name(struct lttng_trigger *trigger,
 		uint64_t unique_id)