2 * Copyright (C) 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
3 * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 * SPDX-License-Identifier: LGPL-2.1-only
7 * This code is originally adapted from userspace-rcu's urcu-wait.h
10 #ifndef LTTNG_WAITER_H
11 #define LTTNG_WAITER_H
19 #include <urcu/wfstack.h>
30 waker(const waker&) noexcept = default;
31 waker(waker&&) noexcept = default;
32 waker& operator=(const waker& other) noexcept = default;
33 waker& operator=(waker&& other) noexcept = default;
40 explicit waker(int32_t& state) noexcept : _state{ state }
44 std::reference_wrapper<int32_t> _state;
53 /* Deactivate copy and assignment. */
54 waiter(const waiter&) = delete;
55 waiter(waiter&&) = delete;
56 waiter& operator=(const waiter&) = delete;
57 waiter& operator=(waiter&&) = delete;
66 cds_wfs_node _wait_queue_node;
70 class wait_queue final {
74 /* Deactivate copy and assignment. */
75 wait_queue(const wait_queue&) = delete;
76 wait_queue(wait_queue&&) = delete;
77 wait_queue& operator=(const wait_queue&) = delete;
78 wait_queue& operator=(wait_queue&&) = delete;
79 ~wait_queue() = default;
82 * Atomically add a waiter to a wait queue.
83 * A full memory barrier is issued before being added to the wait queue.
85 void add(waiter& waiter) noexcept;
87 * Wake every waiter present in the wait queue and remove them from
95 } /* namespace synchro */
96 } /* namespace lttng */
98 #endif /* LTTNG_WAITER_H */