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-rw-r--r--src/common/fiber.cpp222
1 files changed, 222 insertions, 0 deletions
diff --git a/src/common/fiber.cpp b/src/common/fiber.cpp
new file mode 100644
index 000000000..1c1d09ccb
--- /dev/null
+++ b/src/common/fiber.cpp
@@ -0,0 +1,222 @@
+// 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"
+#if defined(_WIN32) || defined(WIN32)
+#include <windows.h>
+#else
+#include <boost/context/detail/fcontext.hpp>
+#endif
+
+namespace Common {
+
+constexpr std::size_t default_stack_size = 256 * 1024; // 256kb
+
+#if defined(_WIN32) || defined(WIN32)
+
+struct Fiber::FiberImpl {
+ LPVOID handle = nullptr;
+ LPVOID rewind_handle = nullptr;
+};
+
+void Fiber::Start() {
+ ASSERT(previous_fiber != nullptr);
+ previous_fiber->guard.unlock();
+ previous_fiber.reset();
+ entry_point(start_parameter);
+ UNREACHABLE();
+}
+
+void Fiber::OnRewind() {
+ ASSERT(impl->handle != nullptr);
+ DeleteFiber(impl->handle);
+ impl->handle = impl->rewind_handle;
+ impl->rewind_handle = nullptr;
+ rewind_point(rewind_parameter);
+ UNREACHABLE();
+}
+
+void Fiber::FiberStartFunc(void* fiber_parameter) {
+ auto fiber = static_cast<Fiber*>(fiber_parameter);
+ fiber->Start();
+}
+
+void Fiber::RewindStartFunc(void* fiber_parameter) {
+ auto fiber = static_cast<Fiber*>(fiber_parameter);
+ fiber->OnRewind();
+}
+
+Fiber::Fiber(std::function<void(void*)>&& entry_point_func, void* start_parameter)
+ : entry_point{std::move(entry_point_func)}, start_parameter{start_parameter} {
+ impl = std::make_unique<FiberImpl>();
+ impl->handle = CreateFiber(default_stack_size, &FiberStartFunc, this);
+}
+
+Fiber::Fiber() : impl{std::make_unique<FiberImpl>()} {}
+
+Fiber::~Fiber() {
+ if (released) {
+ return;
+ }
+ // Make sure the Fiber is not being used
+ const bool locked = guard.try_lock();
+ ASSERT_MSG(locked, "Destroying a fiber that's still running");
+ if (locked) {
+ guard.unlock();
+ }
+ DeleteFiber(impl->handle);
+}
+
+void Fiber::Exit() {
+ ASSERT_MSG(is_thread_fiber, "Exitting non main thread fiber");
+ if (!is_thread_fiber) {
+ return;
+ }
+ ConvertFiberToThread();
+ guard.unlock();
+ released = true;
+}
+
+void Fiber::SetRewindPoint(std::function<void(void*)>&& rewind_func, void* start_parameter) {
+ rewind_point = std::move(rewind_func);
+ rewind_parameter = start_parameter;
+}
+
+void Fiber::Rewind() {
+ ASSERT(rewind_point);
+ ASSERT(impl->rewind_handle == nullptr);
+ impl->rewind_handle = CreateFiber(default_stack_size, &RewindStartFunc, this);
+ SwitchToFiber(impl->rewind_handle);
+}
+
+void Fiber::YieldTo(std::shared_ptr<Fiber>& from, std::shared_ptr<Fiber>& to) {
+ ASSERT_MSG(from != nullptr, "Yielding fiber is null!");
+ ASSERT_MSG(to != nullptr, "Next fiber is null!");
+ to->guard.lock();
+ to->previous_fiber = from;
+ SwitchToFiber(to->impl->handle);
+ ASSERT(from->previous_fiber != nullptr);
+ from->previous_fiber->guard.unlock();
+ from->previous_fiber.reset();
+}
+
+std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
+ std::shared_ptr<Fiber> fiber = std::shared_ptr<Fiber>{new Fiber()};
+ fiber->guard.lock();
+ fiber->impl->handle = ConvertThreadToFiber(nullptr);
+ fiber->is_thread_fiber = true;
+ return fiber;
+}
+
+#else
+
+struct Fiber::FiberImpl {
+ alignas(64) std::array<u8, default_stack_size> stack;
+ alignas(64) std::array<u8, default_stack_size> rewind_stack;
+ u8* stack_limit;
+ u8* rewind_stack_limit;
+ boost::context::detail::fcontext_t context;
+ boost::context::detail::fcontext_t rewind_context;
+};
+
+void Fiber::Start(boost::context::detail::transfer_t& transfer) {
+ ASSERT(previous_fiber != nullptr);
+ previous_fiber->impl->context = transfer.fctx;
+ previous_fiber->guard.unlock();
+ previous_fiber.reset();
+ entry_point(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;
+ rewind_point(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)
+ : entry_point{std::move(entry_point_func)}, start_parameter{start_parameter} {
+ impl = std::make_unique<FiberImpl>();
+ 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);
+}
+
+void Fiber::SetRewindPoint(std::function<void(void*)>&& rewind_func, void* start_parameter) {
+ rewind_point = std::move(rewind_func);
+ rewind_parameter = start_parameter;
+}
+
+Fiber::Fiber() : impl{std::make_unique<FiberImpl>()} {}
+
+Fiber::~Fiber() {
+ if (released) {
+ return;
+ }
+ // Make sure the Fiber is not being used
+ const bool locked = guard.try_lock();
+ ASSERT_MSG(locked, "Destroying a fiber that's still running");
+ if (locked) {
+ guard.unlock();
+ }
+}
+
+void Fiber::Exit() {
+
+ ASSERT_MSG(is_thread_fiber, "Exitting non main thread fiber");
+ if (!is_thread_fiber) {
+ return;
+ }
+ guard.unlock();
+ released = true;
+}
+
+void Fiber::Rewind() {
+ ASSERT(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(std::shared_ptr<Fiber>& from, std::shared_ptr<Fiber>& to) {
+ ASSERT_MSG(from != nullptr, "Yielding fiber is null!");
+ ASSERT_MSG(to != nullptr, "Next fiber is null!");
+ to->guard.lock();
+ to->previous_fiber = from;
+ auto transfer = boost::context::detail::jump_fcontext(to->impl->context, to.get());
+ ASSERT(from->previous_fiber != nullptr);
+ from->previous_fiber->impl->context = transfer.fctx;
+ from->previous_fiber->guard.unlock();
+ from->previous_fiber.reset();
+}
+
+std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
+ std::shared_ptr<Fiber> fiber = std::shared_ptr<Fiber>{new Fiber()};
+ fiber->guard.lock();
+ fiber->is_thread_fiber = true;
+ return fiber;
+}
+
+#endif
+} // namespace Common
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