From f61d0a30ec1c2f300a883e9ef88bdd0264aeafbd Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Fri, 1 Jun 2018 10:37:51 -0700
Subject: [PATCH] ircd::ctx: Add condition_variable for interface compat.

---
 include/ircd/ctx/condition_variable.h | 150 ++++++++++++++++++++++++++
 include/ircd/ctx/ctx.h                |   1 +
 2 files changed, 151 insertions(+)
 create mode 100644 include/ircd/ctx/condition_variable.h

diff --git a/include/ircd/ctx/condition_variable.h b/include/ircd/ctx/condition_variable.h
new file mode 100644
index 000000000..e86fab8b4
--- /dev/null
+++ b/include/ircd/ctx/condition_variable.h
@@ -0,0 +1,150 @@
+// Matrix Construct
+//
+// Copyright (C) Matrix Construct Developers, Authors & Contributors
+// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice is present in all copies. The
+// full license for this software is available in the LICENSE file.
+
+#pragma once
+#define HAVE_IRCD_CTX_CONDITION_VARIABLE_H
+
+namespace ircd::ctx
+{
+	struct condition_variable;
+}
+
+struct ircd::ctx::condition_variable
+{
+	dock d;
+
+  public:
+	template<class lock, class time_point, class predicate> bool wait_until(lock &, time_point&& tp, predicate&& pred);
+	template<class lock, class time_point> std::cv_status wait_until(lock &, time_point&& tp);
+
+	template<class lock, class duration, class predicate> bool wait_for(lock &, const duration &dur, predicate&& pred);
+	template<class lock, class duration> std::cv_status wait_for(lock &, const duration &dur);
+
+	template<class lock, class predicate> void wait(lock &, predicate&& pred);
+	template<class lock> void wait(lock &);
+
+	void notify_all() noexcept;
+	void notify_one() noexcept;
+	void notify() noexcept;
+};
+
+inline void
+ircd::ctx::condition_variable::notify()
+noexcept
+{
+	d.notify();
+}
+
+inline void
+ircd::ctx::condition_variable::notify_one()
+noexcept
+{
+	d.notify_one();
+}
+
+inline void
+ircd::ctx::condition_variable::notify_all()
+noexcept
+{
+	d.notify_all();
+}
+
+template<class lock>
+void
+ircd::ctx::condition_variable::wait(lock &l)
+{
+	const unlock_guard<lock> ul(l);
+	d.wait();
+}
+
+template<class lock,
+         class predicate>
+void
+ircd::ctx::condition_variable::wait(lock &l,
+                                    predicate&& pred)
+{
+	const unlock_guard<lock> ul(l);
+	return d.wait([&l, &pred]
+	{
+		l.lock();
+		const unwind ul{[&l]
+		{
+			l.unlock();
+		}};
+
+		return pred();
+	});
+}
+
+template<class lock,
+         class duration>
+std::cv_status
+ircd::ctx::condition_variable::wait_for(lock &l,
+                                        const duration &dur)
+{
+	const unlock_guard<lock> ul(l);
+	return d.wait_for(dur)?
+		std::cv_status::no_timeout:
+		std::cv_status::timeout;
+}
+
+template<class lock,
+         class duration,
+         class predicate>
+bool
+ircd::ctx::condition_variable::wait_for(lock &l,
+                                        const duration &dur,
+                                        predicate&& pred)
+{
+	const unlock_guard<lock> ul(l);
+	return d.wait_for(dur, [&l, &pred]
+	{
+		l.lock();
+		const unwind ul{[&l]
+		{
+			l.unlock();
+		}};
+
+		return pred();
+	});
+}
+
+template<class lock,
+         class time_point>
+std::cv_status
+ircd::ctx::condition_variable::wait_until(lock &l,
+                                          time_point&& tp)
+{
+	const unlock_guard<lock> ul(l);
+	return d.wait_until(std::forward<time_point>(tp))?
+		std::cv_status::no_timeout:
+		std::cv_status::timeout;
+}
+
+template<class lock,
+         class time_point,
+         class predicate>
+bool
+ircd::ctx::condition_variable::wait_until(lock &l,
+                                          time_point&& tp,
+                                          predicate&& pred)
+{
+	const unlock_guard<lock> ul(l);
+	return d.wait_until(std::forward<time_point>(tp), [&l, &pred]
+	{
+		l.lock();
+		const unwind ul{[&l]
+		{
+			l.unlock();
+		}};
+
+		return pred();
+	});
+}
diff --git a/include/ircd/ctx/ctx.h b/include/ircd/ctx/ctx.h
index 105b6fcfb..c4f1061d2 100644
--- a/include/ircd/ctx/ctx.h
+++ b/include/ircd/ctx/ctx.h
@@ -81,6 +81,7 @@ namespace ircd::ctx
 #include "mutex.h"
 #include "shared_mutex.h"
 #include "unlock_guard.h"
+#include "condition_variable.h"
 #include "peek.h"
 #include "view.h"
 #include "shared_state.h"