mirror of
https://github.com/yuzu-emu/ext-boost.git
synced 2024-12-23 04:35:29 +00:00
350 lines
11 KiB
C++
350 lines
11 KiB
C++
|
|
// Copyright Oliver Kowalke 2017.
|
|
// Distributed under the Boost Software License, Version 1.0.
|
|
// (See accompanying file LICENSE_1_0.txt or copy at
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
|
|
|
#ifndef BOOST_CONTEXT_FIBER_H
|
|
#define BOOST_CONTEXT_FIBER_H
|
|
|
|
#include <boost/context/detail/config.hpp>
|
|
|
|
#include <algorithm>
|
|
#include <cstddef>
|
|
#include <cstdint>
|
|
#include <cstdlib>
|
|
#include <exception>
|
|
#include <functional>
|
|
#include <memory>
|
|
#include <ostream>
|
|
#include <tuple>
|
|
#include <utility>
|
|
|
|
#include <boost/assert.hpp>
|
|
#include <boost/config.hpp>
|
|
#include <boost/intrusive_ptr.hpp>
|
|
|
|
#if defined(BOOST_NO_CXX14_STD_EXCHANGE)
|
|
#include <boost/context/detail/exchange.hpp>
|
|
#endif
|
|
#if defined(BOOST_NO_CXX17_STD_INVOKE)
|
|
#include <boost/context/detail/invoke.hpp>
|
|
#endif
|
|
#include <boost/context/detail/disable_overload.hpp>
|
|
#include <boost/context/detail/exception.hpp>
|
|
#include <boost/context/detail/fcontext.hpp>
|
|
#include <boost/context/detail/tuple.hpp>
|
|
#include <boost/context/fixedsize_stack.hpp>
|
|
#include <boost/context/flags.hpp>
|
|
#include <boost/context/preallocated.hpp>
|
|
#include <boost/context/segmented_stack.hpp>
|
|
#include <boost/context/stack_context.hpp>
|
|
|
|
#ifdef BOOST_HAS_ABI_HEADERS
|
|
# include BOOST_ABI_PREFIX
|
|
#endif
|
|
|
|
#if defined(BOOST_MSVC)
|
|
# pragma warning(push)
|
|
# pragma warning(disable: 4702)
|
|
#endif
|
|
|
|
namespace boost {
|
|
namespace context {
|
|
namespace detail {
|
|
|
|
inline
|
|
transfer_t fiber_unwind( transfer_t t) {
|
|
throw forced_unwind( t.fctx);
|
|
return { nullptr, nullptr };
|
|
}
|
|
|
|
template< typename Rec >
|
|
transfer_t fiber_exit( transfer_t t) noexcept {
|
|
Rec * rec = static_cast< Rec * >( t.data);
|
|
// destroy context stack
|
|
rec->deallocate();
|
|
return { nullptr, nullptr };
|
|
}
|
|
|
|
template< typename Rec >
|
|
void fiber_entry( transfer_t t) noexcept {
|
|
// transfer control structure to the context-stack
|
|
Rec * rec = static_cast< Rec * >( t.data);
|
|
BOOST_ASSERT( nullptr != t.fctx);
|
|
BOOST_ASSERT( nullptr != rec);
|
|
try {
|
|
// jump back to `create_context()`
|
|
t = jump_fcontext( t.fctx, nullptr);
|
|
// start executing
|
|
t.fctx = rec->run( t.fctx);
|
|
} catch ( forced_unwind const& ex) {
|
|
t = { ex.fctx, nullptr };
|
|
#ifndef BOOST_ASSERT_IS_VOID
|
|
const_cast< forced_unwind & >( ex).caught = true;
|
|
#endif
|
|
}
|
|
BOOST_ASSERT( nullptr != t.fctx);
|
|
// destroy context-stack of `this`context on next context
|
|
ontop_fcontext( t.fctx, rec, fiber_exit< Rec >);
|
|
BOOST_ASSERT_MSG( false, "context already terminated");
|
|
}
|
|
|
|
template< typename Ctx, typename Fn >
|
|
transfer_t fiber_ontop( transfer_t t) {
|
|
BOOST_ASSERT( nullptr != t.data);
|
|
auto p = *static_cast< Fn * >( t.data);
|
|
t.data = nullptr;
|
|
// execute function, pass fiber via reference
|
|
Ctx c = p( Ctx{ t.fctx } );
|
|
#if defined(BOOST_NO_CXX14_STD_EXCHANGE)
|
|
return { exchange( c.fctx_, nullptr), nullptr };
|
|
#else
|
|
return { std::exchange( c.fctx_, nullptr), nullptr };
|
|
#endif
|
|
}
|
|
|
|
template< typename Ctx, typename StackAlloc, typename Fn >
|
|
class fiber_record {
|
|
private:
|
|
stack_context sctx_;
|
|
typename std::decay< StackAlloc >::type salloc_;
|
|
typename std::decay< Fn >::type fn_;
|
|
|
|
static void destroy( fiber_record * p) noexcept {
|
|
typename std::decay< StackAlloc >::type salloc = std::move( p->salloc_);
|
|
stack_context sctx = p->sctx_;
|
|
// deallocate fiber_record
|
|
p->~fiber_record();
|
|
// destroy stack with stack allocator
|
|
salloc.deallocate( sctx);
|
|
}
|
|
|
|
public:
|
|
fiber_record( stack_context sctx, StackAlloc && salloc,
|
|
Fn && fn) noexcept :
|
|
sctx_( sctx),
|
|
salloc_( std::forward< StackAlloc >( salloc)),
|
|
fn_( std::forward< Fn >( fn) ) {
|
|
}
|
|
|
|
fiber_record( fiber_record const&) = delete;
|
|
fiber_record & operator=( fiber_record const&) = delete;
|
|
|
|
void deallocate() noexcept {
|
|
destroy( this);
|
|
}
|
|
|
|
fcontext_t run( fcontext_t fctx) {
|
|
// invoke context-function
|
|
#if defined(BOOST_NO_CXX17_STD_INVOKE)
|
|
Ctx c = boost::context::detail::invoke( fn_, Ctx{ fctx } );
|
|
#else
|
|
Ctx c = std::invoke( fn_, Ctx{ fctx } );
|
|
#endif
|
|
#if defined(BOOST_NO_CXX14_STD_EXCHANGE)
|
|
return exchange( c.fctx_, nullptr);
|
|
#else
|
|
return std::exchange( c.fctx_, nullptr);
|
|
#endif
|
|
}
|
|
};
|
|
|
|
template< typename Record, typename StackAlloc, typename Fn >
|
|
fcontext_t create_fiber1( StackAlloc && salloc, Fn && fn) {
|
|
auto sctx = salloc.allocate();
|
|
// reserve space for control structure
|
|
void * storage = reinterpret_cast< void * >(
|
|
( reinterpret_cast< uintptr_t >( sctx.sp) - static_cast< uintptr_t >( sizeof( Record) ) )
|
|
& ~static_cast< uintptr_t >( 0xff) );
|
|
// placment new for control structure on context stack
|
|
Record * record = new ( storage) Record{
|
|
sctx, std::forward< StackAlloc >( salloc), std::forward< Fn >( fn) };
|
|
// 64byte gab between control structure and stack top
|
|
// should be 16byte aligned
|
|
void * stack_top = reinterpret_cast< void * >(
|
|
reinterpret_cast< uintptr_t >( storage) - static_cast< uintptr_t >( 64) );
|
|
void * stack_bottom = reinterpret_cast< void * >(
|
|
reinterpret_cast< uintptr_t >( sctx.sp) - static_cast< uintptr_t >( sctx.size) );
|
|
// create fast-context
|
|
const std::size_t size = reinterpret_cast< uintptr_t >( stack_top) - reinterpret_cast< uintptr_t >( stack_bottom);
|
|
const fcontext_t fctx = make_fcontext( stack_top, size, & fiber_entry< Record >);
|
|
BOOST_ASSERT( nullptr != fctx);
|
|
// transfer control structure to context-stack
|
|
return jump_fcontext( fctx, record).fctx;
|
|
}
|
|
|
|
template< typename Record, typename StackAlloc, typename Fn >
|
|
fcontext_t create_fiber2( preallocated palloc, StackAlloc && salloc, Fn && fn) {
|
|
// reserve space for control structure
|
|
void * storage = reinterpret_cast< void * >(
|
|
( reinterpret_cast< uintptr_t >( palloc.sp) - static_cast< uintptr_t >( sizeof( Record) ) )
|
|
& ~ static_cast< uintptr_t >( 0xff) );
|
|
// placment new for control structure on context-stack
|
|
Record * record = new ( storage) Record{
|
|
palloc.sctx, std::forward< StackAlloc >( salloc), std::forward< Fn >( fn) };
|
|
// 64byte gab between control structure and stack top
|
|
void * stack_top = reinterpret_cast< void * >(
|
|
reinterpret_cast< uintptr_t >( storage) - static_cast< uintptr_t >( 64) );
|
|
void * stack_bottom = reinterpret_cast< void * >(
|
|
reinterpret_cast< uintptr_t >( palloc.sctx.sp) - static_cast< uintptr_t >( palloc.sctx.size) );
|
|
// create fast-context
|
|
const std::size_t size = reinterpret_cast< uintptr_t >( stack_top) - reinterpret_cast< uintptr_t >( stack_bottom);
|
|
const fcontext_t fctx = make_fcontext( stack_top, size, & fiber_entry< Record >);
|
|
BOOST_ASSERT( nullptr != fctx);
|
|
// transfer control structure to context-stack
|
|
return jump_fcontext( fctx, record).fctx;
|
|
}
|
|
|
|
}
|
|
|
|
class fiber {
|
|
private:
|
|
template< typename Ctx, typename StackAlloc, typename Fn >
|
|
friend class detail::fiber_record;
|
|
|
|
template< typename Ctx, typename Fn >
|
|
friend detail::transfer_t
|
|
detail::fiber_ontop( detail::transfer_t);
|
|
|
|
template< typename StackAlloc, typename Fn >
|
|
friend fiber
|
|
callcc( std::allocator_arg_t, StackAlloc &&, Fn &&);
|
|
|
|
template< typename StackAlloc, typename Fn >
|
|
friend fiber
|
|
callcc( std::allocator_arg_t, preallocated, StackAlloc &&, Fn &&);
|
|
|
|
detail::fcontext_t fctx_{ nullptr };
|
|
|
|
fiber( detail::fcontext_t fctx) noexcept :
|
|
fctx_{ fctx } {
|
|
}
|
|
|
|
public:
|
|
fiber() noexcept = default;
|
|
|
|
template< typename Fn, typename = detail::disable_overload< fiber, Fn > >
|
|
fiber( Fn && fn) :
|
|
fiber{ std::allocator_arg, fixedsize_stack(), std::forward< Fn >( fn) } {
|
|
}
|
|
|
|
template< typename StackAlloc, typename Fn >
|
|
fiber( std::allocator_arg_t, StackAlloc && salloc, Fn && fn) :
|
|
fctx_{ detail::create_fiber1< detail::fiber_record< fiber, StackAlloc, Fn > >(
|
|
std::forward< StackAlloc >( salloc), std::forward< Fn >( fn) ) } {
|
|
}
|
|
|
|
template< typename StackAlloc, typename Fn >
|
|
fiber( std::allocator_arg_t, preallocated palloc, StackAlloc && salloc, Fn && fn) :
|
|
fctx_{ detail::create_fiber2< detail::fiber_record< fiber, StackAlloc, Fn > >(
|
|
palloc, std::forward< StackAlloc >( salloc), std::forward< Fn >( fn) ) } {
|
|
}
|
|
|
|
#if defined(BOOST_USE_SEGMENTED_STACKS)
|
|
template< typename Fn >
|
|
fiber( std::allocator_arg_t, segmented_stack, Fn &&);
|
|
|
|
template< typename StackAlloc, typename Fn >
|
|
fiber( std::allocator_arg_t, preallocated, segmented_stack, Fn &&);
|
|
#endif
|
|
|
|
~fiber() {
|
|
if ( BOOST_UNLIKELY( nullptr != fctx_) ) {
|
|
detail::ontop_fcontext(
|
|
#if defined(BOOST_NO_CXX14_STD_EXCHANGE)
|
|
detail::exchange( fctx_, nullptr),
|
|
#else
|
|
std::exchange( fctx_, nullptr),
|
|
#endif
|
|
nullptr,
|
|
detail::fiber_unwind);
|
|
}
|
|
}
|
|
|
|
fiber( fiber && other) noexcept {
|
|
swap( other);
|
|
}
|
|
|
|
fiber & operator=( fiber && other) noexcept {
|
|
if ( BOOST_LIKELY( this != & other) ) {
|
|
fiber tmp = std::move( other);
|
|
swap( tmp);
|
|
}
|
|
return * this;
|
|
}
|
|
|
|
fiber( fiber const& other) noexcept = delete;
|
|
fiber & operator=( fiber const& other) noexcept = delete;
|
|
|
|
fiber resume() && {
|
|
BOOST_ASSERT( nullptr != fctx_);
|
|
return { detail::jump_fcontext(
|
|
#if defined(BOOST_NO_CXX14_STD_EXCHANGE)
|
|
detail::exchange( fctx_, nullptr),
|
|
#else
|
|
std::exchange( fctx_, nullptr),
|
|
#endif
|
|
nullptr).fctx };
|
|
}
|
|
|
|
template< typename Fn >
|
|
fiber resume_with( Fn && fn) && {
|
|
BOOST_ASSERT( nullptr != fctx_);
|
|
auto p = std::forward< Fn >( fn);
|
|
return { detail::ontop_fcontext(
|
|
#if defined(BOOST_NO_CXX14_STD_EXCHANGE)
|
|
detail::exchange( fctx_, nullptr),
|
|
#else
|
|
std::exchange( fctx_, nullptr),
|
|
#endif
|
|
& p,
|
|
detail::fiber_ontop< fiber, decltype(p) >).fctx };
|
|
}
|
|
|
|
explicit operator bool() const noexcept {
|
|
return nullptr != fctx_;
|
|
}
|
|
|
|
bool operator!() const noexcept {
|
|
return nullptr == fctx_;
|
|
}
|
|
|
|
bool operator<( fiber const& other) const noexcept {
|
|
return fctx_ < other.fctx_;
|
|
}
|
|
|
|
template< typename charT, class traitsT >
|
|
friend std::basic_ostream< charT, traitsT > &
|
|
operator<<( std::basic_ostream< charT, traitsT > & os, fiber const& other) {
|
|
if ( nullptr != other.fctx_) {
|
|
return os << other.fctx_;
|
|
} else {
|
|
return os << "{not-a-context}";
|
|
}
|
|
}
|
|
|
|
void swap( fiber & other) noexcept {
|
|
std::swap( fctx_, other.fctx_);
|
|
}
|
|
};
|
|
|
|
inline
|
|
void swap( fiber & l, fiber & r) noexcept {
|
|
l.swap( r);
|
|
}
|
|
|
|
typedef fiber fiber_context;
|
|
|
|
}}
|
|
|
|
#if defined(BOOST_MSVC)
|
|
# pragma warning(pop)
|
|
#endif
|
|
|
|
#ifdef BOOST_HAS_ABI_HEADERS
|
|
# include BOOST_ABI_SUFFIX
|
|
#endif
|
|
|
|
#endif // BOOST_CONTEXT_FIBER_H
|