0
0
Fork 0
mirror of https://github.com/matrix-construct/construct synced 2024-10-31 10:58:54 +01:00
construct/include/ircd/ctx/dock.h

203 lines
3.7 KiB
C++

// 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_DOCK_H
namespace ircd::ctx
{
struct dock;
void terminate(dock &) noexcept;
void interrupt(dock &) noexcept;
void notify(dock &) noexcept;
}
/// dock is a condition variable which has no requirement for locking because
/// the context system does not require mutual exclusion for coherence.
///
class ircd::ctx::dock
{
using predicate = std::function<bool ()>;
list q;
public:
bool empty() const noexcept;
size_t size() const noexcept;
bool waiting(const ctx &) const noexcept;
template<class time_point> bool wait_until(time_point&&, const predicate &);
template<class time_point> bool wait_until(time_point&&);
template<class duration> bool wait_for(const duration &, const predicate &);
template<class duration> bool wait_for(const duration &);
void wait(const predicate &);
void wait();
void terminate_all() noexcept;
void interrupt_all() noexcept;
void notify_all() noexcept;
void notify_one() noexcept;
void notify() noexcept;
};
inline void
ircd::ctx::notify(dock &dock)
noexcept
{
dock.notify();
}
inline void
ircd::ctx::interrupt(dock &dock)
noexcept
{
dock.interrupt_all();
}
inline void
ircd::ctx::terminate(dock &dock)
noexcept
{
dock.terminate_all();
}
//
// dock::dock
//
/// Wake up the next context waiting on the dock
inline void
ircd::ctx::dock::notify_one()
noexcept
{
if(q.empty())
return;
ircd::ctx::notify(*q.front());
}
/// Returns true if notified; false if timed out
template<class duration>
inline bool
ircd::ctx::dock::wait_for(const duration &dur)
{
static const duration zero(0);
assert(current);
const unwind_exceptional renotify{[this]
{
notify_one();
}};
const unwind remove{[this]
{
q.remove(current);
}};
q.push_back(current);
return ircd::ctx::wait<std::nothrow_t>(dur) > zero;
}
/// Returns true if predicate passed; false if timed out
template<class duration>
inline bool
ircd::ctx::dock::wait_for(const duration &dur,
const predicate &pred)
{
static const duration zero(0);
if(pred())
return true;
assert(current);
const unwind_exceptional renotify{[this]
{
notify_one();
}};
const unwind remove{[this]
{
q.remove(current);
}};
q.push_back(current); do
{
const bool expired
{
ircd::ctx::wait<std::nothrow_t>(dur) <= zero
};
if(pred())
return true;
if(expired)
return false;
}
while(1);
}
/// Returns true if notified; false if timed out
template<class time_point>
inline bool
ircd::ctx::dock::wait_until(time_point&& tp)
{
assert(current);
const unwind_exceptional renotify{[this]
{
notify_one();
}};
const unwind remove{[this]
{
q.remove(current);
}};
q.push_back(current);
return !ircd::ctx::wait_until<std::nothrow_t>(tp);
}
/// Returns true if predicate passed; false if timed out
template<class time_point>
inline bool
ircd::ctx::dock::wait_until(time_point&& tp,
const predicate &pred)
{
if(pred())
return true;
assert(current);
const unwind_exceptional renotify{[this]
{
notify_one();
}};
const unwind remove{[this]
{
q.remove(current);
}};
q.push_back(current); do
{
const bool expired
{
ircd::ctx::wait_until<std::nothrow_t>(tp)
};
if(pred())
return true;
if(expired)
return false;
}
while(1);
}