src/bin/lttng-sessiond/rotation-thread.hpp

   1 /*
   2  * Copyright (C) 2017 Julien Desfossez <jdesfossez@efficios.com>
   3  * Copyright (C) 2018 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * SPDX-License-Identifier: GPL-2.0-only
   6  *
   7  */
   8
   9 #ifndef ROTATION_THREAD_H
  10 #define ROTATION_THREAD_H
  11
  12 #include "notification-thread.hpp"
  13 #include "session.hpp"
  14
  15 #include <common/compat/poll.hpp>
  16 #include <common/eventfd.hpp>
  17 #include <common/hashtable/hashtable.hpp>
  18 #include <common/make-unique-wrapper.hpp>
  19 #include <common/pipe.hpp>
  20
  21 #include <lttng/domain.h>
  22 #include <lttng/notification/channel-internal.hpp>
  23
  24 #include <memory>
  25 #include <pthread.h>
  26 #include <semaphore.h>
  27 #include <urcu.h>
  28 #include <urcu/list.h>
  29 #include <urcu/rculfhash.h>
  30
  31 namespace lttng {
  32 namespace sessiond {
  33
  34 enum class rotation_thread_job_type { SCHEDULED_ROTATION, CHECK_PENDING_ROTATION };
  35
  36 struct rotation_thread_timer_queue;
  37
  38 class rotation_thread {
  39 public:
  40         using uptr = std::unique_ptr<rotation_thread>;
  41
  42         rotation_thread(rotation_thread_timer_queue& rotation_timer_queue,
  43                         notification_thread_handle& notification_thread_handle);
  44         rotation_thread(const rotation_thread&) = delete;
  45         rotation_thread(rotation_thread&&) = delete;
  46         rotation_thread& operator=(const rotation_thread&) = delete;
  47         rotation_thread& operator=(rotation_thread&&) = delete;
  48         ~rotation_thread();
  49
  50         /* Only use through the lttng_thread facilities. */
  51         void launch_thread();
  52         bool shutdown() const noexcept;
  53
  54         /*
  55          * Subscribe/unsubscribe the rotation_thread's notification_channel to/from
  56          * session usage notifications to perform size-based rotations.
  57          */
  58         void subscribe_session_consumed_size_rotation(ltt_session& session, std::uint64_t size);
  59         void unsubscribe_session_consumed_size_rotation(ltt_session& session);
  60
  61 private:
  62         void _thread_function() noexcept;
  63         void _run();
  64         void _handle_job_queue();
  65         void _handle_notification(const lttng_notification& notification);
  66         void _handle_notification_channel_activity();
  67
  68         struct rotation_thread_timer_queue& _rotation_timer_queue;
  69         /* Access to the notification thread cmd_queue */
  70         notification_thread_handle& _notification_thread_handle;
  71         /* Thread-specific quit pipe. */
  72         lttng_pipe::uptr _quit_pipe;
  73         lttng_notification_channel::uptr _notification_channel;
  74         /*
  75          * Use an event_fd to wake-up the rotation thread whenever a command
  76          * completes on the notification channel. This ensures that any
  77          * notification that was queued while waiting for a reply to the command is
  78          * eventually consumed.
  79          */
  80         lttng::eventfd _notification_channel_subscribtion_change_eventfd;
  81         lttng_poll_event _events;
  82 };
  83
  84 struct rotation_thread_timer_queue *rotation_thread_timer_queue_create();
  85 void rotation_thread_timer_queue_destroy(struct rotation_thread_timer_queue *queue);
  86 void rotation_thread_enqueue_job(struct rotation_thread_timer_queue *queue,
  87                                  enum rotation_thread_job_type job_type,
  88                                  struct ltt_session *session);
  89
  90 } /* namespace sessiond */
  91 } /* namespace lttng */
  92
  93 #endif /* ROTATION_THREAD_H */