From: Francis Deslauriers <francis.deslauriers@efficios.com>
Date: Mon, 12 Oct 2020 16:24:49 +0000 (-0400)
Subject: Implement event notifier error counter
X-Git-Tag: v2.13.0-rc1~430
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=6566528bd873067b5e68a0599d57044060908e29;p=lttng-ust.git

Implement event notifier error counter

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: Ia8008a162a1e4c881fdc948a390847cb5258e4f7
---

diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index 721b0aed..19726f88 100644
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -511,6 +511,7 @@ struct lttng_event {
 
 struct lttng_event_notifier {
 	uint64_t user_token;
+	uint64_t error_counter_index;
 	int enabled;
 	int registered;			/* has reg'd tracepoint probe */
 	size_t num_captures;		/* Needed to allocate the msgpack array. */
diff --git a/liblttng-ust/event-notifier-notification.c b/liblttng-ust/event-notifier-notification.c
index 6fce4357..f1fb8adc 100644
--- a/liblttng-ust/event-notifier-notification.c
+++ b/liblttng-ust/event-notifier-notification.c
@@ -280,8 +280,24 @@ void notification_append_empty_capture(
 	lttng_msgpack_write_nil(&notif->writer);
 }
 
+static void record_error(struct lttng_event_notifier *event_notifier)
+{
+	struct lttng_event_notifier_group *event_notifier_group =
+			event_notifier->group;
+	size_t dimension_index[1];
+	int ret;
+
+	dimension_index[0] = event_notifier->error_counter_index;
+	ret = event_notifier_group->error_counter->ops->counter_add(
+			event_notifier_group->error_counter->counter,
+			dimension_index, 1);
+	if (ret)
+		WARN_ON_ONCE(1);
+}
+
 static
-void notification_send(struct lttng_event_notifier_notification *notif)
+void notification_send(struct lttng_event_notifier_notification *notif,
+		struct lttng_event_notifier *event_notifier)
 {
 	ssize_t ret;
 	size_t content_len;
@@ -291,7 +307,7 @@ void notification_send(struct lttng_event_notifier_notification *notif)
 
 	assert(notif);
 
-	ust_notif.token = notif->event_notifier_token;
+	ust_notif.token = event_notifier->user_token;
 
 	/*
 	 * Prepare sending the notification from multiple buffers using an
@@ -329,7 +345,8 @@ void notification_send(struct lttng_event_notifier_notification *notif)
 	ret = patient_writev(notif->notification_fd, iov, iovec_count);
 	if (ret == -1) {
 		if (errno == EAGAIN) {
-			DBG("Cannot send event notifier notification without blocking: %s",
+			record_error(event_notifier);
+			DBG("Cannot send event_notifier notification without blocking: %s",
 				strerror(errno));
 		} else {
 			DBG("Error to sending event notifier notification: %s",
@@ -339,7 +356,8 @@ void notification_send(struct lttng_event_notifier_notification *notif)
 	}
 }
 
-void lttng_event_notifier_notification_send(struct lttng_event_notifier *event_notifier,
+void lttng_event_notifier_notification_send(
+		struct lttng_event_notifier *event_notifier,
 		const char *stack_data)
 {
 	/*
@@ -375,5 +393,5 @@ void lttng_event_notifier_notification_send(struct lttng_event_notifier *event_n
 	 * Send the notification (including the capture buffer) to the
 	 * sessiond.
 	 */
-	notification_send(&notif);
+	notification_send(&notif, event_notifier);
 }
diff --git a/liblttng-ust/lttng-events.c b/liblttng-ust/lttng-events.c
index 6a089122..b455c363 100644
--- a/liblttng-ust/lttng-events.c
+++ b/liblttng-ust/lttng-events.c
@@ -841,7 +841,7 @@ socket_error:
 
 static
 int lttng_event_notifier_create(const struct lttng_event_desc *desc,
-		uint64_t token,
+		uint64_t token, uint64_t error_counter_index,
 		struct lttng_event_notifier_group *event_notifier_group)
 {
 	struct lttng_event_notifier *event_notifier;
@@ -864,6 +864,7 @@ int lttng_event_notifier_create(const struct lttng_event_desc *desc,
 
 	event_notifier->group = event_notifier_group;
 	event_notifier->user_token = token;
+	event_notifier->error_counter_index = error_counter_index;
 
 	/* Event notifier will be enabled by enabler sync. */
 	event_notifier->enabled = 0;
@@ -1766,6 +1767,7 @@ void lttng_create_event_notifier_if_missing(
 			 */
 			ret = lttng_event_notifier_create(desc,
 				event_notifier_enabler->user_token,
+				event_notifier_enabler->error_counter_index,
 				event_notifier_group);
 			if (ret) {
 				DBG("Unable to create event_notifier %s, error %d\n",
diff --git a/liblttng-ust/ust-events-internal.h b/liblttng-ust/ust-events-internal.h
index 966fce6e..be5c549c 100644
--- a/liblttng-ust/ust-events-internal.h
+++ b/liblttng-ust/ust-events-internal.h
@@ -46,6 +46,7 @@ struct lttng_event_enabler {
 
 struct lttng_event_notifier_enabler {
 	struct lttng_enabler base;
+	uint64_t error_counter_index;
 	struct cds_list_head node;	/* per-app list of event_notifier enablers */
 	struct cds_list_head capture_bytecode_head;
 	struct lttng_event_notifier_group *group; /* weak ref */