Common Trace Format 2 generation

[deliverable/lttng-tools.git] / src / common / waiter.hpp

diff --git a/src/common/waiter.hpp b/src/common/waiter.hpp
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+++ b/src/common/waiter.hpp
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+/*
+ * Copyright (C) 2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * This code is originally adapted from userspace-rcu's urcu-wait.h
+ */
+
+#ifndef LTTNG_WAITER_H
+#define LTTNG_WAITER_H
+
+#define _LGPL_SOURCE
+
+#include <stdint.h>
+#include <urcu/wfstack.h>
+#include <stdbool.h>
+#include "macros.hpp"
+
+struct lttng_waiter {
+       struct cds_wfs_node wait_queue_node;
+       int32_t state;
+};
+
+void lttng_waiter_init(struct lttng_waiter *waiter);
+
+void lttng_waiter_wait(struct lttng_waiter *waiter);
+
+/*
+ * lttng_waiter_wake_up must only be called by a single waker.
+ * It is invalid for multiple "wake" operations to be invoked
+ * on a single waiter without re-initializing it before.
+ */
+void lttng_waiter_wake_up(struct lttng_waiter *waiter);
+
+#endif /* LTTNG_WAITER_H */