src/common/waiter.hpp

   1 /*
   2  * Copyright (C) 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   3  * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   4  *
   5  * SPDX-License-Identifier: LGPL-2.1-only
   6  *
   7  * This code is originally adapted from userspace-rcu's urcu-wait.h
   8  */
   9
  10 #ifndef LTTNG_WAITER_H
  11 #define LTTNG_WAITER_H
  12
  13 #define _LGPL_SOURCE
  14
  15 #include <stdint.h>
  16 #include <urcu/wfstack.h>
  17 #include <stdbool.h>
  18 #include "macros.hpp"
  19
  20 struct lttng_waiter {
  21         struct cds_wfs_node wait_queue_node;
  22         int32_t state;
  23 };
  24
  25 void lttng_waiter_init(struct lttng_waiter *waiter);
  26
  27 void lttng_waiter_wait(struct lttng_waiter *waiter);
  28
  29 /*
  30  * lttng_waiter_wake_up must only be called by a single waker.
  31  * It is invalid for multiple "wake" operations to be invoked
  32  * on a single waiter without re-initializing it before.
  33  */
  34 void lttng_waiter_wake_up(struct lttng_waiter *waiter);
  35
  36 #endif /* LTTNG_WAITER_H */