src/lttng-event-notifier-notification.c

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * lttng-event-notifier-notification.c
   4  *
   5  * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
   6  */
   7
   8 #include <lttng/events.h>
   9 #include <lttng/event-notifier-notification.h>
  10
  11 void lttng_event_notifier_notification_send(struct lttng_event_notifier *event_notifier)
  12 {
  13         struct lttng_event_notifier_group *event_notifier_group = event_notifier->group;
  14         struct lib_ring_buffer_ctx ctx;
  15         int ret;
  16
  17         if (unlikely(!READ_ONCE(event_notifier->enabled)))
  18                 return;
  19
  20         lib_ring_buffer_ctx_init(&ctx, event_notifier_group->chan, NULL,
  21                         sizeof(event_notifier->user_token),
  22                         lttng_alignof(event_notifier->user_token), -1);
  23         ret = event_notifier_group->ops->event_reserve(&ctx, 0);
  24         if (ret < 0) {
  25                 //TODO: error handling with counter maps
  26                 //silently drop for now.
  27                 WARN_ON_ONCE(1);
  28                 return;
  29         }
  30         lib_ring_buffer_align_ctx(&ctx, lttng_alignof(event_notifier->user_token));
  31         event_notifier_group->ops->event_write(&ctx, &event_notifier->user_token,
  32                         sizeof(event_notifier->user_token));
  33         event_notifier_group->ops->event_commit(&ctx);
  34         irq_work_queue(&event_notifier_group->wakeup_pending);
  35 }