From 423acf53b740ce96ca37988aad79ddf5013645ef Mon Sep 17 00:00:00 2001 From: bunnei Date: Tue, 9 Nov 2021 20:51:47 -0800 Subject: [PATCH] hle: kernel: KLightLock: Migrate to updated KThreadQueue. --- src/core/hle/kernel/k_light_lock.cpp | 69 ++++++++++++++-------------- src/core/hle/kernel/k_light_lock.h | 2 +- 2 files changed, 36 insertions(+), 35 deletions(-) diff --git a/src/core/hle/kernel/k_light_lock.cpp b/src/core/hle/kernel/k_light_lock.cpp index 0896e705fa..5e8f1a5102 100644 --- a/src/core/hle/kernel/k_light_lock.cpp +++ b/src/core/hle/kernel/k_light_lock.cpp @@ -5,44 +5,54 @@ #include "core/hle/kernel/k_light_lock.h" #include "core/hle/kernel/k_scheduler.h" #include "core/hle/kernel/k_thread.h" +#include "core/hle/kernel/k_thread_queue.h" #include "core/hle/kernel/kernel.h" namespace Kernel { +namespace { + +class ThreadQueueImplForKLightLock final : public KThreadQueue { +public: + explicit ThreadQueueImplForKLightLock(KernelCore& kernel_) : KThreadQueue(kernel_) {} + + virtual void CancelWait([[maybe_unused]] KThread* waiting_thread, + [[maybe_unused]] ResultCode wait_result, + [[maybe_unused]] bool cancel_timer_task) override { + // Do nothing, waiting to acquire a light lock cannot be canceled. + } +}; + +} // namespace + void KLightLock::Lock() { const uintptr_t cur_thread = reinterpret_cast(GetCurrentThreadPointer(kernel)); - const uintptr_t cur_thread_tag = (cur_thread | 1); while (true) { uintptr_t old_tag = tag.load(std::memory_order_relaxed); - while (!tag.compare_exchange_weak(old_tag, (old_tag == 0) ? cur_thread : old_tag | 1, + while (!tag.compare_exchange_weak(old_tag, (old_tag == 0) ? cur_thread : (old_tag | 1), std::memory_order_acquire)) { - if ((old_tag | 1) == cur_thread_tag) { - return; - } } - if ((old_tag == 0) || ((old_tag | 1) == cur_thread_tag)) { + if (old_tag == 0 || this->LockSlowPath(old_tag | 1, cur_thread)) { break; } - - LockSlowPath(old_tag | 1, cur_thread); } } void KLightLock::Unlock() { const uintptr_t cur_thread = reinterpret_cast(GetCurrentThreadPointer(kernel)); + uintptr_t expected = cur_thread; - do { - if (expected != cur_thread) { - return UnlockSlowPath(cur_thread); - } - } while (!tag.compare_exchange_weak(expected, 0, std::memory_order_release)); + if (!tag.compare_exchange_strong(expected, 0, std::memory_order_release)) { + this->UnlockSlowPath(cur_thread); + } } -void KLightLock::LockSlowPath(uintptr_t _owner, uintptr_t _cur_thread) { +bool KLightLock::LockSlowPath(uintptr_t _owner, uintptr_t _cur_thread) { KThread* cur_thread = reinterpret_cast(_cur_thread); + ThreadQueueImplForKLightLock wait_queue(kernel); // Pend the current thread waiting on the owner thread. { @@ -50,30 +60,23 @@ void KLightLock::LockSlowPath(uintptr_t _owner, uintptr_t _cur_thread) { // Ensure we actually have locking to do. if (tag.load(std::memory_order_relaxed) != _owner) { - return; + return false; } // Add the current thread as a waiter on the owner. - KThread* owner_thread = reinterpret_cast(_owner & ~1ULL); + KThread* owner_thread = reinterpret_cast(_owner & ~1ul); cur_thread->SetAddressKey(reinterpret_cast(std::addressof(tag))); owner_thread->AddWaiter(cur_thread); - // Set thread states. - cur_thread->SetState(ThreadState::Waiting); + // Begin waiting to hold the lock. + cur_thread->BeginWait(std::addressof(wait_queue)); if (owner_thread->IsSuspended()) { owner_thread->ContinueIfHasKernelWaiters(); } } - // We're no longer waiting on the lock owner. - { - KScopedSchedulerLock sl{kernel}; - - if (KThread* owner_thread = cur_thread->GetLockOwner(); owner_thread != nullptr) { - owner_thread->RemoveWaiter(cur_thread); - } - } + return true; } void KLightLock::UnlockSlowPath(uintptr_t _cur_thread) { @@ -81,22 +84,20 @@ void KLightLock::UnlockSlowPath(uintptr_t _cur_thread) { // Unlock. { - KScopedSchedulerLock sl{kernel}; + KScopedSchedulerLock sl(kernel); // Get the next owner. - s32 num_waiters = 0; + s32 num_waiters; KThread* next_owner = owner_thread->RemoveWaiterByKey( std::addressof(num_waiters), reinterpret_cast(std::addressof(tag))); // Pass the lock to the next owner. uintptr_t next_tag = 0; if (next_owner != nullptr) { - next_tag = reinterpret_cast(next_owner); - if (num_waiters > 1) { - next_tag |= 0x1; - } + next_tag = + reinterpret_cast(next_owner) | static_cast(num_waiters > 1); - next_owner->SetState(ThreadState::Runnable); + next_owner->EndWait(ResultSuccess); if (next_owner->IsSuspended()) { next_owner->ContinueIfHasKernelWaiters(); @@ -110,7 +111,7 @@ void KLightLock::UnlockSlowPath(uintptr_t _cur_thread) { } // Write the new tag value. - tag.store(next_tag); + tag.store(next_tag, std::memory_order_release); } } diff --git a/src/core/hle/kernel/k_light_lock.h b/src/core/hle/kernel/k_light_lock.h index ad853661d4..4163b8a854 100644 --- a/src/core/hle/kernel/k_light_lock.h +++ b/src/core/hle/kernel/k_light_lock.h @@ -20,7 +20,7 @@ public: void Unlock(); - void LockSlowPath(uintptr_t owner, uintptr_t cur_thread); + bool LockSlowPath(uintptr_t owner, uintptr_t cur_thread); void UnlockSlowPath(uintptr_t cur_thread);