mirror of
https://github.com/matrix-construct/construct
synced 2024-10-30 18:39:02 +01:00
151 lines
2.4 KiB
C++
151 lines
2.4 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_MUTEX_H
|
|
|
|
namespace ircd::ctx
|
|
{
|
|
class mutex;
|
|
|
|
template<class queue> void release_sequence(queue &);
|
|
}
|
|
|
|
//
|
|
// The mutex only allows one context to lock it and continue,
|
|
// additional contexts are queued. This can be used with std::
|
|
// locking concepts.
|
|
//
|
|
class ircd::ctx::mutex
|
|
{
|
|
bool m;
|
|
list q;
|
|
|
|
public:
|
|
bool try_lock();
|
|
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(mutex &&) noexcept;
|
|
mutex(const mutex &) = delete;
|
|
mutex &operator=(mutex &&) noexcept;
|
|
mutex &operator=(const mutex &) = delete;
|
|
~mutex() noexcept;
|
|
};
|
|
|
|
inline
|
|
ircd::ctx::mutex::mutex()
|
|
:m{false}
|
|
{
|
|
}
|
|
|
|
inline
|
|
ircd::ctx::mutex::mutex(mutex &&o)
|
|
noexcept
|
|
:m{std::move(o.m)}
|
|
{
|
|
o.m = false;
|
|
}
|
|
|
|
inline
|
|
ircd::ctx::mutex &
|
|
ircd::ctx::mutex::operator=(mutex &&o)
|
|
noexcept
|
|
{
|
|
this->~mutex();
|
|
std::swap(m, o.m);
|
|
return *this;
|
|
}
|
|
|
|
inline
|
|
ircd::ctx::mutex::~mutex()
|
|
noexcept
|
|
{
|
|
assert(!m);
|
|
}
|
|
|
|
inline void
|
|
ircd::ctx::mutex::unlock()
|
|
{
|
|
assert(m);
|
|
m = false;
|
|
release_sequence(q);
|
|
}
|
|
|
|
inline void
|
|
ircd::ctx::mutex::lock()
|
|
{
|
|
if(likely(try_lock()))
|
|
return;
|
|
|
|
q.push_back(current);
|
|
while(!try_lock())
|
|
wait();
|
|
}
|
|
|
|
template<class duration>
|
|
bool
|
|
ircd::ctx::mutex::try_lock_for(const duration &d)
|
|
{
|
|
return try_lock_until(steady_clock::now() + d);
|
|
}
|
|
|
|
template<class time_point>
|
|
bool
|
|
ircd::ctx::mutex::try_lock_until(const time_point &tp)
|
|
{
|
|
if(likely(try_lock()))
|
|
return true;
|
|
|
|
q.push_back(current);
|
|
while(!try_lock())
|
|
{
|
|
if(unlikely(wait_until<std::nothrow_t>(tp)))
|
|
{
|
|
q.remove(current);
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
inline bool
|
|
ircd::ctx::mutex::try_lock()
|
|
{
|
|
if(m)
|
|
return false;
|
|
|
|
m = true;
|
|
return true;
|
|
}
|
|
|
|
template<class queue>
|
|
void
|
|
ircd::ctx::release_sequence(queue &q)
|
|
{
|
|
ctx *next; do
|
|
{
|
|
if(!q.empty())
|
|
{
|
|
next = q.front();
|
|
q.pop_front();
|
|
}
|
|
else next = nullptr;
|
|
}
|
|
while(next == current);
|
|
|
|
if(next)
|
|
yield(*next);
|
|
}
|