ircd::util: Elide std::function overhead for util::unwind suite.

include/ircd/ctx/dock.h

@@ -52,7 +52,7 @@ ircd::ctx::dock::wait_for(const duration &dur)
 	static const duration zero(0);
 
 	assert(current);
-	const unwind::exceptional renotify{[this]
+	const unwind_exceptional renotify{[this]
 	{
 		notify_one();
 	}};
@@ -78,7 +78,7 @@ ircd::ctx::dock::wait_for(const duration &dur,
 		return true;
 
 	assert(current);
-	const unwind::exceptional renotify{[this]
+	const unwind_exceptional renotify{[this]
 	{
 		notify_one();
 	}};
@@ -110,7 +110,7 @@ bool
 ircd::ctx::dock::wait_until(time_point&& tp)
 {
 	assert(current);
-	const unwind::exceptional renotify{[this]
+	const unwind_exceptional renotify{[this]
 	{
 		notify_one();
 	}};
@@ -134,7 +134,7 @@ ircd::ctx::dock::wait_until(time_point&& tp,
 		return true;
 
 	assert(current);
-	const unwind::exceptional renotify{[this]
+	const unwind_exceptional renotify{[this]
 	{
 		notify_one();
 	}};

include/ircd/util/unwind.h

@@ -11,11 +11,18 @@
 #pragma once
 #define HAVE_IRCD_UTIL_UNWIND_H
 
-namespace ircd {
-inline namespace util
+namespace ircd
 {
-	struct unwind;
-}}
+	inline namespace util
+	{
+		template<class F> struct unwind;
+		template<class F> struct unwind_nominal;
+		template<class F> struct unwind_exceptional;
+		struct unwind_defer;
+		struct unwind_nominal_assertion;
+		struct unwind_exceptional_assertion;
+	}
+}
 
 //
 // Fundamental scope-unwind utilities establishing actions during destruction
@@ -23,15 +30,11 @@ inline namespace util
 
 /// Unconditionally executes the provided code when the object goes out of scope.
 ///
+template<class F = void (*)()>
 struct ircd::util::unwind
 {
-	struct defer;
-	struct nominal;
-	struct exceptional;
+	F func;
 
-	const std::function<void ()> func;
-
-	template<class F>
 	unwind(F&& func)
 	:func{std::forward<F>(func)}
 	{}
@@ -49,24 +52,22 @@ struct ircd::util::unwind
 /// The function is expected to be executed and the likely() should pipeline
 /// that branch and make this device cheaper to use under normal circumstances.
 ///
-struct ircd::util::unwind::nominal
+template<class F = void (*)()>
+struct ircd::util::unwind_nominal
 {
-	struct assertion;
+	F func;
 
-	const std::function<void ()> func;
-
-	template<class F>
-	nominal(F&& func)
+	unwind_nominal(F&& func)
 	:func{std::forward<F>(func)}
 	{}
 
-	~nominal() noexcept __attribute__((always_inline))
+	~unwind_nominal() noexcept __attribute__((always_inline))
 	{
 		if(likely(!std::uncaught_exceptions()))
 			func();
 	}
 
-	nominal(const nominal &) = delete;
+	unwind_nominal(const unwind_nominal &) = delete;
 };
 
 /// Executes function only if unwind is taking place because exception thrown
@@ -76,40 +77,38 @@ struct ircd::util::unwind::nominal
 /// optimize the pipeline for the nominal path, making this device as cheap
 /// as possible to use.
 ///
-struct ircd::util::unwind::exceptional
+template<class F = void (*)()>
+struct ircd::util::unwind_exceptional
 {
-	struct assertion;
+	F func;
 
-	const std::function<void ()> func;
-
-	template<class F>
-	exceptional(F&& func)
+	unwind_exceptional(F&& func)
 	:func{std::forward<F>(func)}
 	{}
 
-	~exceptional() noexcept __attribute__((always_inline))
+	~unwind_exceptional() noexcept __attribute__((always_inline))
 	{
 		if(unlikely(std::uncaught_exceptions()))
 			func();
 	}
 
-	exceptional(const exceptional &) = delete;
+	unwind_exceptional(const unwind_exceptional &) = delete;
 };
 
 /// Posts function to the event loop at the unwind rather than executing it
 /// as with nominal/exceptional.
 ///
-struct ircd::util::unwind::defer
+struct ircd::util::unwind_defer
 {
 	std::function<void ()> func;
 
 	template<class F>
-	defer(F&& func)
+	unwind_defer(F&& func)
 	:func{std::forward<F>(func)}
 	{}
 
-	defer(const defer &) = delete;
-	~defer() noexcept;
+	unwind_defer(const unwind_defer &) = delete;
+	~unwind_defer() noexcept;
 };
 
 /// Asserts that unwind is occurring without any exception. This allows some
@@ -118,9 +117,9 @@ struct ircd::util::unwind::defer
 /// exception is expected thus placing other guarantees should not be required
 /// if this guarantee is met.
 ///
-struct ircd::util::unwind::nominal::assertion
+struct ircd::util::unwind_nominal_assertion
 {
-	~assertion() noexcept
+	~unwind_nominal_assertion() noexcept
 	{
 		assert(likely(!std::uncaught_exceptions()));
 	}
@@ -129,9 +128,9 @@ struct ircd::util::unwind::nominal::assertion
 /// Complements exceptional::assertion. This triggers an assertion when
 /// unwinding WITHOUT an exception.
 ///
-struct ircd::util::unwind::exceptional::assertion
+struct ircd::util::unwind_exceptional_assertion
 {
-	~assertion() noexcept
+	~unwind_exceptional_assertion() noexcept
 	{
 		assert(likely(std::uncaught_exceptions()));
 	}

ircd/ctx.cc

@@ -1264,7 +1264,7 @@ ircd::ctx::context::context(const string_view &name,
 	// we expect the context to be committed to entry. If the POST flag is
 	// supplied and it gets lost in the asio queue it will not be entered, and
 	// will not be able to free itself; that will leak.
-	const unwind::nominal release{[this]
+	const unwind_nominal release{[this]
 	{
 		assert(c);
 		if(c->flags & context::DETACH)
@@ -2729,7 +2729,7 @@ void
 ircd::ctx::dock::wait()
 {
 	assert(current);
-	const unwind::exceptional renotify{[this]
+	const unwind_exceptional renotify{[this]
 	{
 		notify_one();
 	}};
@@ -2750,7 +2750,7 @@ ircd::ctx::dock::wait(const predicate &pred)
 		return;
 
 	assert(current);
-	const unwind::exceptional renotify{[this]
+	const unwind_exceptional renotify{[this]
 	{
 		notify_one();
 	}};

ircd/ircd.cc

@@ -270,7 +270,7 @@ noexcept try
 
 	// When this function completes without exception, subsystems are done shutting down and IRCd
 	// transitions to HALT.
-	const unwind::defer halted{[]
+	const unwind_defer halted{[]
 	{
 		run::set(run::level::HALT);
 	}};

ircd/net.cc

@@ -3153,7 +3153,7 @@ try
 
 	assert(!fini);
 	set_timeout(opts.timeout);
-	const unwind::exceptional unset{[this]
+	const unwind_exceptional unset{[this]
 	{
 		cancel_timeout();
 	}};

ircd/resource.cc

@@ -529,7 +529,7 @@ try
 		client.request.param, tokens(pathparm, '/', client.request.param)
 	};
 
-	const unwind::nominal completions{[this]
+	const unwind_nominal completions{[this]
 	{
 		++stats->completions;
 	}};

ircd/server.cc

@@ -1174,7 +1174,7 @@ try
 	if(op_fini)
 		return;
 
-	const unwind::exceptional failure{[this]
+	const unwind_exceptional failure{[this]
 	{
 		op_resolve = false;
 		err_set(std::current_exception());
@@ -1850,7 +1850,7 @@ ircd::server::link::open(const net::open_opts &open_opts)
 
 	op_init = true;
 	op_open = true;
-	const unwind::exceptional unhandled{[this]
+	const unwind_exceptional unhandled{[this]
 	{
 		op_init = false;
 		op_open = false;
@@ -1938,7 +1938,7 @@ ircd::server::link::wait_writable()
 
 	assert(ready());
 	op_write = true;
-	const unwind::exceptional unhandled{[this]
+	const unwind_exceptional unhandled{[this]
 	{
 		op_write = false;
 	}};
@@ -2119,7 +2119,7 @@ ircd::server::link::wait_readable()
 
 	assert(ready());
 	op_read = true;
-	const unwind::exceptional unhandled{[this]
+	const unwind_exceptional unhandled{[this]
 	{
 		op_read = false;
 	}};

ircd/util.cc

@@ -509,7 +509,7 @@ ircd::util::a2u(const mutable_buffer &out,
 // util/unwind.h
 //
 
-ircd::util::unwind::defer::~defer()
+ircd::util::unwind_defer::~unwind_defer()
 noexcept
 {
 	ircd::defer

matrix/matrix.cc

@@ -247,7 +247,7 @@ catch(const m::error &e)
 /*
 ircd::m::init::modules::modules()
 {
-	const unwind::exceptional unload{[this]
+	const unwind_exceptional unload{[this]
 	{
 		this->fini_imports();
 	}};

modules/federation/invite.cc

@@ -161,7 +161,7 @@ put__invite(client &client,
 
 	// We don't want this eval throwing an exception because the response has
 	// already been made for this request.
-	const unwind::nominal::assertion na;
+	const unwind_nominal_assertion na;
 	vmopts.nothrows = -1;
 
 	m::vm::eval

modules/federation/sender.cc

@@ -345,7 +345,7 @@ try
 	};
 
 	txns.emplace_back(*this, std::move(content), std::move(opts));
-	const unwind::nominal::assertion na;
+	const unwind_nominal_assertion na;
 	curtxn = &txns.back();
 	q.clear();
 	log::debug

modules/media/media.cc

@@ -307,7 +307,7 @@ try
 	};
 
 	create(room, user_id, "file");
-	const unwind::exceptional purge{[&room]
+	const unwind_exceptional purge{[&room]
 	{
 		m::room::purge(room);
 	}};

modules/web_root.cc

@@ -234,7 +234,7 @@ try
 		file_size
 	};
 
-	const unwind::exceptional terminate{[&client]
+	const unwind_exceptional terminate{[&client]
 	{
 		client.close(net::dc::RST, net::close_ignore);
 	}};