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 {
  35         SCHEDULED_ROTATION,
  36         CHECK_PENDING_ROTATION
  37 };
  38
  39 struct rotation_thread_timer_queue;
  40
  41 class rotation_thread {
  42 public:
  43         using uptr = std::unique_ptr<rotation_thread>;
  44
  45         rotation_thread(rotation_thread_timer_queue& rotation_timer_queue,
  46                                notification_thread_handle& notification_thread_handle);
  47         ~rotation_thread();
  48
  49         /* Only use through the lttng_thread facilities. */
  50         void launch_thread();
  51         bool shutdown() const noexcept;
  52
  53         /*
  54          * Subscribe/unsubscribe the rotation_thread's notification_channel to/from
  55          * session usage notifications to perform size-based rotations.
  56          */
  57         void subscribe_session_consumed_size_rotation(ltt_session& session, std::uint64_t size);
  58         void unsubscribe_session_consumed_size_rotation(ltt_session& session);
  59
  60 private:
  61         void _thread_function() noexcept;
  62         void _run();
  63         void _handle_job_queue();
  64         void _handle_notification(const lttng_notification& notification);
  65         void _handle_notification_channel_activity();
  66
  67         struct rotation_thread_timer_queue& _rotation_timer_queue;
  68         /* Access to the notification thread cmd_queue */
  69         notification_thread_handle& _notification_thread_handle;
  70         /* Thread-specific quit pipe. */
  71         lttng_pipe::uptr _quit_pipe;
  72         lttng_notification_channel::uptr _notification_channel;
  73         /*
  74          * Use an event_fd to wake-up the rotation thread whenever a command
  75          * completes on the notification channel. This ensures that any
  76          * notification that was queued while waiting for a reply to the command is
  77          * eventually consumed.
  78          */
  79         lttng::eventfd _notification_channel_subscribtion_change_eventfd;
  80         lttng_poll_event _events;
  81 };
  82
  83 struct rotation_thread_timer_queue *rotation_thread_timer_queue_create(void);
  84 void rotation_thread_timer_queue_destroy(struct rotation_thread_timer_queue *queue);
  85 void rotation_thread_enqueue_job(struct rotation_thread_timer_queue *queue,
  86                                  enum rotation_thread_job_type job_type,
  87                                  struct ltt_session *session);
  88
  89 } /* namespace sessiond */
  90 } /* namespace lttng */
  91
  92 #endif /* ROTATION_THREAD_H */