mirror of
https://github.com/matrix-construct/construct
synced 2024-11-30 02:32:43 +01:00
170 lines
3.6 KiB
C++
170 lines
3.6 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_LIST_H
|
|
|
|
namespace ircd::ctx
|
|
{
|
|
struct list;
|
|
}
|
|
|
|
/// A special linked-list for contexts. Each ircd::ctx has space for one and
|
|
/// only one node on its internal ctx::ctx structure. It can only participate
|
|
/// in one ctx::list at a time. This forms the structural basis for mutexes,
|
|
/// condition variables and other interleaving primitives which form queues
|
|
/// of contexts.
|
|
///
|
|
/// This device is strictly for context switching purposes. It is minimal,
|
|
/// usage is specific to this purpose, and not a general list to be used
|
|
/// elsewhere. Furthermore, this is too lightweight for even the
|
|
/// ircd::allocator::node strategy. Custom operations are implemented for
|
|
/// maximum space efficiency in both the object instance and the ctx::ctx.
|
|
///
|
|
class ircd::ctx::list
|
|
{
|
|
ctx *head {nullptr};
|
|
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 &);
|
|
|
|
public:
|
|
const ctx *front() const;
|
|
const ctx *back() const;
|
|
ctx *front();
|
|
ctx *back();
|
|
|
|
// until convention
|
|
bool until(const std::function<bool (const ctx &)> &) const;
|
|
bool until(const std::function<bool (ctx &)> &);
|
|
|
|
// reverse until convention
|
|
bool runtil(const std::function<bool (const ctx &)> &) const;
|
|
bool runtil(const std::function<bool (ctx &)> &);
|
|
|
|
// iteration
|
|
void for_each(const std::function<void (const ctx &)> &) const;
|
|
void for_each(const std::function<void (ctx &)> &);
|
|
|
|
// reverse iteration
|
|
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;
|
|
|
|
void push_front(ctx *const & = current);
|
|
void push_back(ctx *const & = current);
|
|
void push(ctx *const & = current); // push_back
|
|
|
|
ctx *pop_front();
|
|
ctx *pop_back();
|
|
ctx *pop(); // pop_front
|
|
|
|
void remove(ctx *const & = current);
|
|
|
|
list() = default;
|
|
list(list &&) noexcept;
|
|
list(const list &) = delete;
|
|
list &operator=(list &&) noexcept;
|
|
list &operator=(const list &) = delete;
|
|
~list() noexcept;
|
|
};
|
|
|
|
inline
|
|
ircd::ctx::list::list(list &&o)
|
|
noexcept
|
|
:head{std::move(o.head)}
|
|
,tail{std::move(o.tail)}
|
|
{
|
|
o.head = nullptr;
|
|
o.tail = nullptr;
|
|
}
|
|
|
|
inline
|
|
ircd::ctx::list &
|
|
ircd::ctx::list::operator=(list &&o)
|
|
noexcept
|
|
{
|
|
this->~list();
|
|
std::swap(head, o.head);
|
|
std::swap(tail, o.tail);
|
|
return *this;
|
|
}
|
|
|
|
inline
|
|
ircd::ctx::list::~list()
|
|
noexcept
|
|
{
|
|
assert(empty());
|
|
}
|
|
|
|
inline ircd::ctx::ctx *
|
|
ircd::ctx::list::pop()
|
|
{
|
|
return pop_front();
|
|
}
|
|
|
|
inline void
|
|
ircd::ctx::list::push(ctx *const &c)
|
|
{
|
|
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
|
|
{
|
|
assert((!head && !tail) || (head && tail));
|
|
return !head;
|
|
}
|
|
|
|
inline ircd::ctx::ctx *
|
|
ircd::ctx::list::back()
|
|
{
|
|
return tail;
|
|
}
|
|
|
|
inline ircd::ctx::ctx *
|
|
ircd::ctx::list::front()
|
|
{
|
|
return head;
|
|
}
|
|
|
|
inline const ircd::ctx::ctx *
|
|
ircd::ctx::list::back()
|
|
const
|
|
{
|
|
return tail;
|
|
}
|
|
|
|
inline const ircd::ctx::ctx *
|
|
ircd::ctx::list::front()
|
|
const
|
|
{
|
|
return head;
|
|
}
|