mirror of
https://github.com/matrix-construct/construct
synced 2024-12-30 17:34:04 +01:00
143 lines
3.3 KiB
C++
143 lines
3.3 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_UNINTERRUPTIBLE_H
|
|
|
|
namespace ircd::ctx
|
|
{
|
|
bool interruptible(const ctx &) noexcept;
|
|
void interruptible(ctx &, const bool &) noexcept;
|
|
}
|
|
|
|
namespace ircd::ctx {
|
|
inline namespace this_ctx
|
|
{
|
|
struct uninterruptible;
|
|
|
|
bool interruptible() noexcept;
|
|
void interruptible(const bool &);
|
|
void interruptible(const bool &, std::nothrow_t) noexcept;
|
|
}}
|
|
|
|
/// An instance of uninterruptible will suppress interrupts sent to the
|
|
/// context for the scope. Suppression does not discard any interrupt,
|
|
/// it merely ignores it at all interruption points until the suppression
|
|
/// ends, after which it will be thrown.
|
|
///
|
|
struct ircd::ctx::this_ctx::uninterruptible
|
|
{
|
|
struct nothrow;
|
|
|
|
bool theirs;
|
|
|
|
uninterruptible(const bool & = true);
|
|
uninterruptible(uninterruptible &&) = delete;
|
|
uninterruptible(const uninterruptible &) = delete;
|
|
~uninterruptible() noexcept(false);
|
|
};
|
|
|
|
/// A variant of uinterruptible for users that must guarantee the ending of
|
|
/// the suppression scope will not be an interruption point. The default
|
|
/// behavior for uninterruptible is to throw, even from its destructor, to
|
|
/// fulfill the interruption request without any more delay.
|
|
///
|
|
struct ircd::ctx::this_ctx::uninterruptible::nothrow
|
|
{
|
|
bool theirs;
|
|
|
|
nothrow(const bool & = true) noexcept;
|
|
nothrow(nothrow &&) = delete;
|
|
nothrow(const nothrow &) = delete;
|
|
~nothrow() noexcept;
|
|
};
|
|
|
|
//
|
|
// uninterruptible
|
|
//
|
|
|
|
inline
|
|
ircd::ctx::this_ctx::uninterruptible::uninterruptible(const bool &ours)
|
|
:theirs
|
|
{
|
|
interruptible(cur())
|
|
}
|
|
{
|
|
interruptible(!ours);
|
|
}
|
|
|
|
inline
|
|
ircd::ctx::this_ctx::uninterruptible::~uninterruptible()
|
|
noexcept(false)
|
|
{
|
|
interruptible(theirs);
|
|
}
|
|
|
|
//
|
|
// uninterruptible::nothrow
|
|
//
|
|
|
|
inline
|
|
ircd::ctx::this_ctx::uninterruptible::nothrow::nothrow(const bool &ours)
|
|
noexcept
|
|
:theirs
|
|
{
|
|
interruptible(cur())
|
|
}
|
|
{
|
|
interruptible(!ours, std::nothrow);
|
|
}
|
|
|
|
inline
|
|
ircd::ctx::this_ctx::uninterruptible::nothrow::~nothrow()
|
|
noexcept
|
|
{
|
|
interruptible(theirs, std::nothrow);
|
|
}
|
|
|
|
//
|
|
// interruptible
|
|
//
|
|
|
|
inline void
|
|
ircd::ctx::this_ctx::interruptible(const bool &b,
|
|
std::nothrow_t)
|
|
noexcept
|
|
{
|
|
interruptible(cur(), b);
|
|
}
|
|
|
|
inline bool
|
|
ircd::ctx::this_ctx::interruptible()
|
|
noexcept
|
|
{
|
|
return interruptible(cur());
|
|
}
|
|
|
|
/// Marks `ctx` for whether to allow or suppress interruption. Suppression
|
|
/// does not ignore an interrupt itself, it only ignores the interruption
|
|
/// points. Thus when a suppression ends if the interrupt flag was ever set
|
|
/// the next interruption point will throw as expected.
|
|
inline void
|
|
ircd::ctx::interruptible(ctx &ctx,
|
|
const bool &b)
|
|
noexcept
|
|
{
|
|
flags(ctx) ^= (flags(ctx) ^ (ulong(b) - 1)) & context::NOINTERRUPT;
|
|
assert(bool(flags(ctx) & context::NOINTERRUPT) == !b);
|
|
assert(interruptible(ctx) == b);
|
|
}
|
|
|
|
inline bool
|
|
ircd::ctx::interruptible(const ctx &ctx)
|
|
noexcept
|
|
{
|
|
return ~flags(ctx) & context::NOINTERRUPT;
|
|
}
|