From b6149b429eb4fa166f829f80ecbfdc8c3de5a90b Mon Sep 17 00:00:00 2001
From: Jason Volk <jason@zemos.net>
Date: Tue, 10 Sep 2019 10:19:50 -0700
Subject: [PATCH] ircd::ctx::dock: Add noexcept to interface observers.

ircd::ctx: Propagate noexcept on hot leafs;

ircd::ctx::list: Deinline size().
---
 include/ircd/ctx/dock.h  |  4 +--
 include/ircd/ctx/list.h  | 57 +++++++++++++++++-----------------------
 include/ircd/ctx/mutex.h | 14 +++++-----
 ircd/ctx.cc              | 43 ++++++++++++++++++++++++++++--
 modules/console.cc       |  6 +++--
 5 files changed, 79 insertions(+), 45 deletions(-)

diff --git a/include/ircd/ctx/dock.h b/include/ircd/ctx/dock.h
index fcd1bb748..78e5383ee 100644
--- a/include/ircd/ctx/dock.h
+++ b/include/ircd/ctx/dock.h
@@ -28,8 +28,8 @@ class ircd::ctx::dock
 	void notify(ctx &) noexcept;
 
   public:
-	bool empty() const;
-	size_t size() const;
+	bool empty() const noexcept;
+	size_t size() const noexcept;
 
 	template<class time_point> bool wait_until(time_point&&, const predicate &);
 	template<class time_point> bool wait_until(time_point&&);
diff --git a/include/ircd/ctx/list.h b/include/ircd/ctx/list.h
index db7e5ff13..efd4bb23b 100644
--- a/include/ircd/ctx/list.h
+++ b/include/ircd/ctx/list.h
@@ -37,16 +37,16 @@ struct ircd::ctx::list
 	ctx *tail {nullptr};
 
 	// Get next or prev entry in ctx
-	static const ctx *next(const ctx *const &);
-	static const ctx *prev(const ctx *const &);
-	static ctx *&next(ctx *const &);
-	static ctx *&prev(ctx *const &);
+	static const ctx *next(const ctx *const &) noexcept;
+	static const ctx *prev(const ctx *const &) noexcept;
+	static ctx *&next(ctx *const &) noexcept;
+	static ctx *&prev(ctx *const &) noexcept;
 
   public:
-	const ctx *front() const;
-	const ctx *back() const;
-	ctx *front();
-	ctx *back();
+	const ctx *front() const noexcept;
+	const ctx *back() const noexcept;
+	ctx *front() noexcept;
+	ctx *back() noexcept;
 
 	// iteration
 	bool for_each(const std::function<bool (const ctx &)> &) const;
@@ -60,18 +60,18 @@ struct ircd::ctx::list
 	void rfor_each(const std::function<void (const ctx &)> &) const;
 	void rfor_each(const std::function<void (ctx &)> &);
 
-	bool empty() const;
-	size_t size() const;
+	bool empty() const noexcept;
+	size_t size() const noexcept;
 
-	void push_front(ctx *const & = current);
-	void push_back(ctx *const & = current);
-	void push(ctx *const & = current);       // push_back
+	void push_front(ctx *const & = current) noexcept;
+	void push_back(ctx *const & = current) noexcept;
+	void push(ctx *const & = current) noexcept;            // push_back
 
-	ctx *pop_front();
-	ctx *pop_back();
-	ctx *pop();                              // pop_front
+	ctx *pop_front() noexcept;
+	ctx *pop_back() noexcept;
+	ctx *pop() noexcept;                                   // pop_front
 
-	void remove(ctx *const & = current);
+	void remove(ctx *const & = current) noexcept;
 
 	list() = default;
 	list(list &&) noexcept;
@@ -119,32 +119,21 @@ noexcept
 
 inline ircd::ctx::ctx *
 ircd::ctx::list::pop()
+noexcept
 {
 	return pop_front();
 }
 
 inline void
 ircd::ctx::list::push(ctx *const &c)
+noexcept
 {
 	push_back(c);
 }
 
-inline size_t
-ircd::ctx::list::size()
-const
-{
-	size_t i{0};
-	for_each([&i](const ctx &)
-	{
-		++i;
-	});
-
-	return i;
-}
-
 inline bool
 ircd::ctx::list::empty()
-const
+const noexcept
 {
 	assert((!head && !tail) || (head && tail));
 	return !head;
@@ -152,26 +141,28 @@ const
 
 inline ircd::ctx::ctx *
 ircd::ctx::list::back()
+noexcept
 {
 	return tail;
 }
 
 inline ircd::ctx::ctx *
 ircd::ctx::list::front()
+noexcept
 {
 	return head;
 }
 
 inline const ircd::ctx::ctx *
 ircd::ctx::list::back()
-const
+const noexcept
 {
 	return tail;
 }
 
 inline const ircd::ctx::ctx *
 ircd::ctx::list::front()
-const
+const noexcept
 {
 	return head;
 }
diff --git a/include/ircd/ctx/mutex.h b/include/ircd/ctx/mutex.h
index e9b7d5ec9..2223333a7 100644
--- a/include/ircd/ctx/mutex.h
+++ b/include/ircd/ctx/mutex.h
@@ -27,17 +27,17 @@ class ircd::ctx::mutex
 	bool m;
 
   public:
-	bool locked() const;
-	size_t waiting() const;
+	bool locked() const noexcept;
+	size_t waiting() const noexcept;
 
-	bool try_lock();
+	bool try_lock() noexcept;
 	template<class time_point> bool try_lock_until(const time_point &);
 	template<class duration> bool try_lock_for(const duration &);
 
 	void lock();
 	void unlock();
 
-	mutex();
+	mutex() noexcept;
 	mutex(mutex &&) noexcept;
 	mutex(const mutex &) = delete;
 	mutex &operator=(mutex &&) noexcept;
@@ -47,6 +47,7 @@ class ircd::ctx::mutex
 
 inline
 ircd::ctx::mutex::mutex()
+noexcept
 :m{false}
 {
 }
@@ -125,6 +126,7 @@ ircd::ctx::mutex::try_lock_until(const time_point &tp)
 
 inline bool
 ircd::ctx::mutex::try_lock()
+noexcept
 {
 	if(locked())
 		return false;
@@ -135,14 +137,14 @@ ircd::ctx::mutex::try_lock()
 
 inline size_t
 ircd::ctx::mutex::waiting()
-const
+const noexcept
 {
 	return q.size();
 }
 
 inline bool
 ircd::ctx::mutex::locked()
-const
+const noexcept
 {
 	return m;
 }
diff --git a/ircd/ctx.cc b/ircd/ctx.cc
index b9e35d313..ce4e32bec 100644
--- a/ircd/ctx.cc
+++ b/ircd/ctx.cc
@@ -751,6 +751,7 @@ noexcept
 // uinterruptible
 //
 
+[[gnu::hot]]
 ircd::ctx::this_ctx::uninterruptible::uninterruptible()
 :theirs
 {
@@ -760,6 +761,7 @@ ircd::ctx::this_ctx::uninterruptible::uninterruptible()
 	interruptible(false);
 }
 
+[[gnu::hot]]
 ircd::ctx::this_ctx::uninterruptible::~uninterruptible()
 noexcept(false)
 {
@@ -770,6 +772,7 @@ noexcept(false)
 // uninterruptible::nothrow
 //
 
+[[gnu::hot]]
 ircd::ctx::this_ctx::uninterruptible::nothrow::nothrow()
 noexcept
 :theirs
@@ -780,6 +783,7 @@ noexcept
 	interruptible(false, std::nothrow);
 }
 
+[[gnu::hot]]
 ircd::ctx::this_ctx::uninterruptible::nothrow::~nothrow()
 noexcept
 {
@@ -1006,6 +1010,7 @@ ircd::ctx::continuation::noop_interruptor{[]
 // continuation
 //
 
+[[gnu::hot]]
 ircd::ctx::continuation::continuation(const predicate &pred,
                                       const interruptor &intr,
                                       const yield_closure &closure)
@@ -1083,6 +1088,7 @@ ircd::ctx::continuation::continuation(const predicate &pred,
 	}
 }
 
+[[gnu::hot]]
 ircd::ctx::continuation::~continuation()
 noexcept
 {
@@ -1105,6 +1111,7 @@ noexcept
 	// pointer while the context is awake.
 }
 
+[[gnu::hot]]
 ircd::ctx::continuation::operator
 boost::asio::yield_context &()
 noexcept
@@ -1114,6 +1121,7 @@ noexcept
 	return *self->yc;
 }
 
+[[gnu::hot]]
 ircd::ctx::continuation::operator
 const boost::asio::yield_context &()
 const noexcept
@@ -2705,7 +2713,7 @@ noexcept
 /// The number of contexts waiting in the queue.
 size_t
 ircd::ctx::dock::size()
-const
+const noexcept
 {
 	return q.size();
 }
@@ -2713,7 +2721,7 @@ const
 /// The number of contexts waiting in the queue.
 bool
 ircd::ctx::dock::empty()
-const
+const noexcept
 {
 	return q.empty();
 }
@@ -2723,8 +2731,10 @@ const
 // ctx_list.h
 //
 
+[[gnu::hot]]
 void
 ircd::ctx::list::remove(ctx *const &c)
+noexcept
 {
 	assert(c);
 
@@ -2747,8 +2757,10 @@ ircd::ctx::list::remove(ctx *const &c)
 	prev(c) = nullptr;
 }
 
+[[gnu::hot]]
 ircd::ctx::ctx *
 ircd::ctx::list::pop_back()
+noexcept
 {
 	const auto tail
 	{
@@ -2778,8 +2790,10 @@ ircd::ctx::list::pop_back()
 	return tail;
 }
 
+[[gnu::hot]]
 ircd::ctx::ctx *
 ircd::ctx::list::pop_front()
+noexcept
 {
 	const auto head
 	{
@@ -2809,8 +2823,10 @@ ircd::ctx::list::pop_front()
 	return head;
 }
 
+[[gnu::hot]]
 void
 ircd::ctx::list::push_front(ctx *const &c)
+noexcept
 {
 	assert(next(c) == nullptr);
 	assert(prev(c) == nullptr);
@@ -2829,8 +2845,10 @@ ircd::ctx::list::push_front(ctx *const &c)
 	head = c;
 }
 
+[[gnu::hot]]
 void
 ircd::ctx::list::push_back(ctx *const &c)
+noexcept
 {
 	assert(next(c) == nullptr);
 	assert(prev(c) == nullptr);
@@ -2849,6 +2867,19 @@ ircd::ctx::list::push_back(ctx *const &c)
 	tail = c;
 }
 
+size_t
+ircd::ctx::list::size()
+const noexcept
+{
+	size_t i{0};
+	for_each([&i](const ctx &)
+	{
+		++i;
+	});
+
+	return i;
+}
+
 void
 ircd::ctx::list::rfor_each(const std::function<void (ctx &)> &closure)
 {
@@ -2921,29 +2952,37 @@ const
 	return true;
 }
 
+[[gnu::hot]]
 ircd::ctx::ctx *&
 ircd::ctx::list::prev(ctx *const &c)
+noexcept
 {
 	assert(c);
 	return c->node.prev;
 }
 
+[[gnu::hot]]
 ircd::ctx::ctx *&
 ircd::ctx::list::next(ctx *const &c)
+noexcept
 {
 	assert(c);
 	return c->node.next;
 }
 
+[[gnu::hot]]
 const ircd::ctx::ctx *
 ircd::ctx::list::prev(const ctx *const &c)
+noexcept
 {
 	assert(c);
 	return c->node.prev;
 }
 
+[[gnu::hot]]
 const ircd::ctx::ctx *
 ircd::ctx::list::next(const ctx *const &c)
+noexcept
 {
 	assert(c);
 	return c->node.next;
diff --git a/modules/console.cc b/modules/console.cc
index 879841316..5f924d3c8 100644
--- a/modules/console.cc
+++ b/modules/console.cc
@@ -5101,8 +5101,10 @@ console_cmd__net__host(opt &out, const string_view &line)
 		net::dns::resolve(hostport, opts, cbarr);
 
 	const ctx::uninterruptible ui;
-	while(!done)
-		dock.wait();
+	dock.wait([&done]
+	{
+		return done;
+	});
 
 	if(eptr)
 		std::rethrow_exception(eptr);