mirror of
https://github.com/matrix-construct/construct
synced 2024-11-27 01:02:46 +01:00
120 lines
3.4 KiB
C++
120 lines
3.4 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_THIS_CTX_H
|
|
|
|
/// Interface to the currently running context
|
|
namespace ircd::ctx { inline namespace this_ctx
|
|
{
|
|
struct ctx &cur() noexcept; ///< Assumptional reference to *current
|
|
const uint64_t &id() noexcept; // Unique ID for cur ctx
|
|
string_view name() noexcept; // Optional label for cur ctx
|
|
ulong cycles() noexcept; // misc profiling related
|
|
|
|
bool interruption_requested() noexcept; // interruption(cur())
|
|
void interruption_point(); // throws if interruption_requested()
|
|
bool interruptible() noexcept;
|
|
|
|
void interruptible(const bool &, std::nothrow_t) noexcept;
|
|
void interruptible(const bool &);
|
|
|
|
void yield(); // Allow other contexts to run before returning.
|
|
}}
|
|
|
|
namespace ircd::ctx
|
|
{
|
|
/// Points to the currently running context or null for main stack (do not modify)
|
|
extern thread_local ctx *current;
|
|
}
|
|
|
|
namespace ircd
|
|
{
|
|
namespace this_ctx = ctx::this_ctx;
|
|
}
|
|
|
|
/// View the name of the currently running context, or "*" if no context is
|
|
/// currently running.
|
|
inline ircd::string_view
|
|
ircd::ctx::this_ctx::name()
|
|
noexcept
|
|
{
|
|
return current? name(cur()) : "*"_sv;
|
|
}
|
|
|
|
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());
|
|
}
|
|
|
|
/// Throws interrupted if the currently running context was interrupted
|
|
/// and clears the interrupt flag.
|
|
inline void
|
|
ircd::ctx::this_ctx::interruptible(const bool &b)
|
|
{
|
|
const bool theirs
|
|
{
|
|
interruptible(cur())
|
|
};
|
|
|
|
if(unlikely(theirs && !b && interruption_requested()))
|
|
interruption_point();
|
|
|
|
interruptible(cur(), b);
|
|
|
|
if(unlikely(!theirs && b && interruption_requested()))
|
|
interruption_point();
|
|
}
|
|
|
|
/// Returns true if the currently running context was interrupted and clears
|
|
/// the interrupt flag.
|
|
inline bool
|
|
ircd::ctx::this_ctx::interruption_requested()
|
|
noexcept
|
|
{
|
|
return interruption(cur()) || termination(cur());
|
|
}
|
|
|
|
/// Calculate the current TSC (reference cycle count) accumulated for this
|
|
/// context only. This is done by first calculating a cycle count for the
|
|
/// current slice/epoch (see: ctx/prof.h) which is where the RDTSC sample
|
|
/// occurs. This count is added to an accumulator value saved in the ctx
|
|
/// structure. The accumulator value is updated at the end of each execution
|
|
/// slice, thus giving us the cycle count for this ctx only, up to this point.
|
|
extern inline ulong
|
|
__attribute__((flatten, always_inline, gnu_inline, artificial))
|
|
ircd::ctx::this_ctx::cycles()
|
|
noexcept
|
|
{
|
|
const auto slice(prof::cur_slice_cycles());
|
|
const auto accumulated(cycles(cur()));
|
|
return accumulated + slice;
|
|
}
|
|
|
|
/// Reference to the currently running context. Call if you expect to be in a
|
|
/// context. Otherwise use the ctx::current pointer.
|
|
inline ircd::ctx::ctx &
|
|
__attribute__((always_inline))
|
|
ircd::ctx::this_ctx::cur()
|
|
noexcept
|
|
{
|
|
assert(current);
|
|
return *current;
|
|
}
|