common: fiber: Use boost::context instead of native fibers on Windows.

1 files changed, 8 insertions, 106 deletions

diff --git a/src/common/fiber.cpp b/src/common/fiber.cpp
index 3e3029cd1..3978c8624 100644
--- a/src/common/fiber.cpp
+++ b/src/common/fiber.cpp
@@ -6,17 +6,16 @@
 #include "common/fiber.h"
 #include "common/spin_lock.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
+constexpr std::size_t default_stack_size = 256 * 1024;
 
 struct Fiber::FiberImpl {
+    alignas(64) std::array<u8, default_stack_size> stack;
+    alignas(64) std::array<u8, default_stack_size> rewind_stack;
+
     SpinLock guard{};
     std::function<void(void*)> entry_point;
     std::function<void(void*)> rewind_point;
@@ -26,17 +25,10 @@ struct Fiber::FiberImpl {
     bool is_thread_fiber{};
     bool released{};
 
-#if defined(_WIN32) || defined(WIN32)
-    LPVOID handle = nullptr;
-    LPVOID rewind_handle = nullptr;
-#else
-    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;
-#endif
+    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) {
@@ -48,95 +40,6 @@ void Fiber::SetRewindPoint(std::function<void(void*)>&& rewind_func, void* rewin
     impl->rewind_parameter = rewind_param;
 }
 
-#if defined(_WIN32) || defined(WIN32)
-
-void Fiber::Start() {
-    ASSERT(impl->previous_fiber != nullptr);
-    impl->previous_fiber->impl->guard.unlock();
-    impl->previous_fiber.reset();
-    impl->entry_point(impl->start_parameter);
-    UNREACHABLE();
-}
-
-void Fiber::OnRewind() {
-    ASSERT(impl->handle != nullptr);
-    DeleteFiber(impl->handle);
-    impl->handle = impl->rewind_handle;
-    impl->rewind_handle = nullptr;
-    impl->rewind_point(impl->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)
-    : impl{std::make_unique<FiberImpl>()} {
-    impl->entry_point = std::move(entry_point_func);
-    impl->start_parameter = start_parameter;
-    impl->handle = CreateFiber(default_stack_size, &FiberStartFunc, this);
-}
-
-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();
-    }
-    DeleteFiber(impl->handle);
-}
-
-void Fiber::Exit() {
-    ASSERT_MSG(impl->is_thread_fiber, "Exitting non main thread fiber");
-    if (!impl->is_thread_fiber) {
-        return;
-    }
-    ConvertFiberToThread();
-    impl->guard.unlock();
-    impl->released = true;
-}
-
-void Fiber::Rewind() {
-    ASSERT(impl->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->impl->guard.lock();
-    to->impl->previous_fiber = from;
-    SwitchToFiber(to->impl->handle);
-    ASSERT(from->impl->previous_fiber != nullptr);
-    from->impl->previous_fiber->impl->guard.unlock();
-    from->impl->previous_fiber.reset();
-}
-
-std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
-    std::shared_ptr<Fiber> fiber = std::shared_ptr<Fiber>{new Fiber()};
-    fiber->impl->guard.lock();
-    fiber->impl->handle = ConvertThreadToFiber(nullptr);
-    fiber->impl->is_thread_fiber = true;
-    return fiber;
-}
-
-#else
-
 void Fiber::Start(boost::context::detail::transfer_t& transfer) {
     ASSERT(impl->previous_fiber != nullptr);
     impl->previous_fiber->impl->context = transfer.fctx;
@@ -229,5 +132,4 @@ std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
     return fiber;
 }
 
-#endif
 } // namespace Common