1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
|
// Copyright 2020 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include "common/assert.h"
#include "common/fiber.h"
#include "common/spin_lock.h"
#include "common/virtual_buffer.h"
#include <boost/context/detail/fcontext.hpp>
namespace Common {
constexpr std::size_t default_stack_size = 256 * 1024;
struct Fiber::FiberImpl {
FiberImpl() : stack{default_stack_size}, rewind_stack{default_stack_size} {}
VirtualBuffer<u8> stack;
VirtualBuffer<u8> rewind_stack;
SpinLock guard{};
std::function<void(void*)> entry_point;
std::function<void(void*)> rewind_point;
void* rewind_parameter{};
void* start_parameter{};
Fiber* previous_fiber;
bool is_thread_fiber{};
bool released{};
u8* stack_limit{};
u8* rewind_stack_limit{};
boost::context::detail::fcontext_t context{};
boost::context::detail::fcontext_t rewind_context{};
};
void Fiber::SetStartParameter(void* new_parameter) {
impl->start_parameter = new_parameter;
}
void Fiber::SetRewindPoint(std::function<void(void*)>&& rewind_func, void* rewind_param) {
impl->rewind_point = std::move(rewind_func);
impl->rewind_parameter = rewind_param;
}
void Fiber::Start(boost::context::detail::transfer_t& transfer) {
ASSERT(impl->previous_fiber != nullptr);
impl->previous_fiber->impl->context = transfer.fctx;
impl->previous_fiber->impl->guard.unlock();
impl->previous_fiber = nullptr;
impl->entry_point(impl->start_parameter);
UNREACHABLE();
}
void Fiber::OnRewind([[maybe_unused]] boost::context::detail::transfer_t& transfer) {
ASSERT(impl->context != nullptr);
impl->context = impl->rewind_context;
impl->rewind_context = nullptr;
u8* tmp = impl->stack_limit;
impl->stack_limit = impl->rewind_stack_limit;
impl->rewind_stack_limit = tmp;
impl->rewind_point(impl->rewind_parameter);
UNREACHABLE();
}
void Fiber::FiberStartFunc(boost::context::detail::transfer_t transfer) {
auto* fiber = static_cast<Fiber*>(transfer.data);
fiber->Start(transfer);
}
void Fiber::RewindStartFunc(boost::context::detail::transfer_t transfer) {
auto* fiber = static_cast<Fiber*>(transfer.data);
fiber->OnRewind(transfer);
}
Fiber::Fiber(std::function<void(void*)>&& entry_point_func, void* start_parameter)
: impl{std::make_unique<FiberImpl>()} {
impl->entry_point = std::move(entry_point_func);
impl->start_parameter = start_parameter;
impl->stack_limit = impl->stack.data();
impl->rewind_stack_limit = impl->rewind_stack.data();
u8* stack_base = impl->stack_limit + default_stack_size;
impl->context =
boost::context::detail::make_fcontext(stack_base, impl->stack.size(), FiberStartFunc);
}
Fiber::Fiber() : impl{std::make_unique<FiberImpl>()} {}
Fiber::~Fiber() {
if (impl->released) {
return;
}
// Make sure the Fiber is not being used
const bool locked = impl->guard.try_lock();
ASSERT_MSG(locked, "Destroying a fiber that's still running");
if (locked) {
impl->guard.unlock();
}
}
void Fiber::Exit() {
ASSERT_MSG(impl->is_thread_fiber, "Exitting non main thread fiber");
if (!impl->is_thread_fiber) {
return;
}
impl->guard.unlock();
impl->released = true;
}
void Fiber::Rewind() {
ASSERT(impl->rewind_point);
ASSERT(impl->rewind_context == nullptr);
u8* stack_base = impl->rewind_stack_limit + default_stack_size;
impl->rewind_context =
boost::context::detail::make_fcontext(stack_base, impl->stack.size(), RewindStartFunc);
boost::context::detail::jump_fcontext(impl->rewind_context, this);
}
void Fiber::YieldTo(Fiber* from, Fiber* to) {
ASSERT_MSG(from != nullptr, "Yielding fiber is null!");
ASSERT_MSG(to != nullptr, "Next fiber is null!");
to->impl->guard.lock();
to->impl->previous_fiber = from;
auto transfer = boost::context::detail::jump_fcontext(to->impl->context, to);
ASSERT(from->impl->previous_fiber != nullptr);
from->impl->previous_fiber->impl->context = transfer.fctx;
from->impl->previous_fiber->impl->guard.unlock();
from->impl->previous_fiber = nullptr;
}
std::unique_ptr<Fiber> Fiber::ThreadToFiber() {
std::unique_ptr<Fiber> fiber = std::unique_ptr<Fiber>{new Fiber()};
fiber->impl->guard.lock();
fiber->impl->is_thread_fiber = true;
return fiber;
}
} // namespace Common
|
