86 lines
2.6 KiB
C++
86 lines
2.6 KiB
C++
// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
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// SPDX-License-Identifier: GPL-2.0-or-later
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#pragma once
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#include <atomic>
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#include "common/assert.h"
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#include "core/hle/kernel/k_interrupt_manager.h"
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#include "core/hle/kernel/k_spin_lock.h"
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#include "core/hle/kernel/k_thread.h"
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#include "core/hle/kernel/kernel.h"
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#include "core/hle/kernel/physical_core.h"
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namespace Kernel {
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class KernelCore;
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template <typename SchedulerType>
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class KAbstractSchedulerLock {
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public:
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explicit KAbstractSchedulerLock(KernelCore& kernel_) : kernel{kernel_} {}
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bool IsLockedByCurrentThread() const {
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return owner_thread == GetCurrentThreadPointer(kernel);
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}
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void Lock() {
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// If we are shutting down the kernel, none of this is relevant anymore.
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if (kernel.IsShuttingDown()) {
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return;
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}
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if (IsLockedByCurrentThread()) {
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// If we already own the lock, we can just increment the count.
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ASSERT(lock_count > 0);
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lock_count++;
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} else {
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// Otherwise, we want to disable scheduling and acquire the spinlock.
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SchedulerType::DisableScheduling(kernel);
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spin_lock.Lock();
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// For debug, ensure that our state is valid.
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ASSERT(lock_count == 0);
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ASSERT(owner_thread == nullptr);
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// Increment count, take ownership.
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lock_count = 1;
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owner_thread = GetCurrentThreadPointer(kernel);
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}
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}
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void Unlock() {
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// If we are shutting down the kernel, none of this is relevant anymore.
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if (kernel.IsShuttingDown()) {
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return;
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}
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ASSERT(IsLockedByCurrentThread());
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ASSERT(lock_count > 0);
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// Release an instance of the lock.
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if ((--lock_count) == 0) {
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// Perform a memory barrier here.
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std::atomic_thread_fence(std::memory_order_seq_cst);
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// We're no longer going to hold the lock. Take note of what cores need scheduling.
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const u64 cores_needing_scheduling =
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SchedulerType::UpdateHighestPriorityThreads(kernel);
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// Note that we no longer hold the lock, and unlock the spinlock.
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owner_thread = nullptr;
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spin_lock.Unlock();
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// Enable scheduling, and perform a rescheduling operation.
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SchedulerType::EnableScheduling(kernel, cores_needing_scheduling);
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}
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}
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private:
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KernelCore& kernel;
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KAlignedSpinLock spin_lock{};
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s32 lock_count{};
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std::atomic<KThread*> owner_thread{};
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};
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} // namespace Kernel
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