ircd::ctx: Add queue: amalgam of a standard queue container with a dock.

configure.ac

@@ -328,6 +328,7 @@ RB_CHK_SYSHEADER([map],            [MAP])
 RB_CHK_SYSHEADER([set],            [SET])
 RB_CHK_SYSHEADER([list],           [LIST])
 RB_CHK_SYSHEADER([stack],          [STACK])
+RB_CHK_SYSHEADER([queue],          [QUEUE])
 RB_CHK_SYSHEADER([deque],          [DEQUE])
 RB_CHK_SYSHEADER([array],          [ARRAY])
 RB_CHK_SYSHEADER([vector],         [VECTOR])

include/ircd/ctx.h

@@ -105,6 +105,7 @@ using ctx::timeout;
 #include "ctx/context.h"
 #include "ctx/prof.h"
 #include "ctx/dock.h"
+#include "ctx/queue.h"
 #include "ctx/mutex.h"
 #include "ctx/shared_state.h"
 #include "ctx/promise.h"

include/ircd/ctx/queue.h

@@ -0,0 +1,148 @@
+/*
+ *  Copyright (C) 2016 Charybdis Development Team
+ *  Copyright (C) 2016 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+#define HAVE_IRCD_CTX_QUEUE_H
+
+namespace ircd {
+namespace ctx  {
+
+template<class T>
+class queue
+{
+	struct dock dock;
+	std::queue<T> q;
+
+  public:
+	auto empty() const                           { return q.empty();                               }
+	auto size() const                            { return q.size();                                }
+
+	// Consumer interface; waits for item and std::move() it off the queue
+	template<class time_point> T pop_until(time_point&&);
+	template<class duration> T pop_for(const duration &);
+	T pop();
+
+	// Producer interface; emplace item on the queue and notify consumer
+	template<class... args> void emplace(args&&...);
+	void push(const T &);
+	void push(T &&) noexcept;
+
+	queue() = default;
+	~queue() noexcept;
+};
+
+template<class T>
+queue<T>::~queue()
+noexcept
+{
+	assert(q.empty());
+}
+
+template<class T>
+void
+queue<T>::push(T &&t)
+noexcept
+{
+	q.push(std::move(t));
+	dock.notify();
+}
+
+template<class T>
+void
+queue<T>::push(const T &t)
+{
+	q.push(t);
+	dock.notify();
+}
+
+template<class T>
+template<class... args>
+void
+queue<T>::emplace(args&&... a)
+{
+	q.emplace(std::forward<args>(a)...);
+	dock.notify();
+}
+
+template<class T>
+T
+queue<T>::pop()
+{
+	dock.wait([this]
+	{
+		return !q.empty();
+	});
+
+	const scope pop([this]
+	{
+		q.pop();
+	});
+
+	auto &ret(q.front());
+	return std::move(ret);
+}
+
+template<class T>
+template<class duration>
+T
+queue<T>::pop_for(const duration &dur)
+{
+	const auto status(dock.wait_for(dur, [this]
+	{
+		return !q.empty();
+	}));
+
+	if(status == cv_status::timeout)
+		throw timeout();
+
+	const scope pop([this]
+	{
+		q.pop();
+	});
+
+	auto &ret(q.front());
+	return std::move(ret);
+}
+
+template<class T>
+template<class time_point>
+T
+queue<T>::pop_until(time_point&& tp)
+{
+	const auto status(dock.wait_until(tp, [this]
+	{
+		return !q.empty();
+	}));
+
+	if(status == cv_status::timeout)
+		throw timeout();
+
+	const scope pop([this]
+	{
+		q.pop();
+	});
+
+	auto &ret(q.front());
+	return std::move(ret);
+}
+
+} // namespace ctx
+} // namespace ircd

include/rb/requires.h

@@ -79,6 +79,7 @@ extern "C" {
 #include <RB_INC_FORWARD_LIST
 #include <RB_INC_UNORDERED_MAP
 #include <RB_INC_DEQUE
+#include <RB_INC_QUEUE
 #include <RB_INC_SSTREAM
 #include <RB_INC_FSTREAM
 #include <RB_INC_IOSTREAM