event-notifier: Initialize `_notifier_notification` struct to zero

[lttng-ust.git] / liblttng-ust / event-notifier-notification.c

diff --git a/liblttng-ust/event-notifier-notification.c b/liblttng-ust/event-notifier-notification.c
index 6fce4357fe85fe5d1511495b675449b5e10797a6..5bbbbd31064a6743a2b2d7b2119d704a4c063f28 100644 (file)
--- a/liblttng-ust/event-notifier-notification.c
+++ b/liblttng-ust/event-notifier-notification.c
@@ -21,9 +21,9 @@
 #define _LGPL_SOURCE
 
 #include <assert.h>
-#include <byteswap.h>
 #include <errno.h>
 #include <lttng/ust-events.h>
+#include <lttng/ust-endian.h>
 #include <usterr-signal-safe.h>
 
 #include "../libmsgpack/msgpack.h"
@@ -280,18 +280,47 @@ 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;
+       struct lttng_counter *error_counter;
+       size_t dimension_index[1];
+       int ret;
+
+       error_counter = CMM_LOAD_SHARED(event_notifier_group->error_counter);
+       /*
+        * load-acquire paired with store-release orders creation of the
+        * error counter and setting error_counter_len before the
+        * error_counter is used.
+        * Currently a full memory barrier is used, which could be
+        * turned into acquire-release barriers.
+        */
+       cmm_smp_mb();
+       /* This group may not have an error counter attached to it. */
+       if (!error_counter)
+               return;
+
+       dimension_index[0] = event_notifier->error_counter_index;
+       ret = event_notifier_group->error_counter->ops->counter_add(
+                       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;
        int iovec_count = 1;
-       struct lttng_ust_event_notifier_notification ust_notif;
+       struct lttng_ust_event_notifier_notification ust_notif = {0};
        struct iovec iov[2];
 
        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 +358,8 @@ 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 +369,8 @@ 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 +406,5 @@ 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);
 }