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-rw-r--r--src/core/hle/kernel/k_scheduler_lock.h76
1 files changed, 76 insertions, 0 deletions
diff --git a/src/core/hle/kernel/k_scheduler_lock.h b/src/core/hle/kernel/k_scheduler_lock.h
new file mode 100644
index 000000000..d46f5fc04
--- /dev/null
+++ b/src/core/hle/kernel/k_scheduler_lock.h
@@ -0,0 +1,76 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+// This file references various implementation details from Atmosphere, an open-source firmware for
+// the Nintendo Switch. Copyright 2018-2020 Atmosphere-NX.
+
+#pragma once
+
+#include "common/assert.h"
+#include "common/spin_lock.h"
+#include "core/hardware_properties.h"
+
+namespace Kernel {
+
+class KernelCore;
+
+template <typename SchedulerType>
+class KAbstractSchedulerLock {
+private:
+ KernelCore& kernel;
+ Common::SpinLock spin_lock;
+ s32 lock_count;
+ Core::EmuThreadHandle owner_thread;
+
+public:
+ KAbstractSchedulerLock(KernelCore& kernel)
+ : kernel{kernel}, spin_lock(), lock_count(0),
+ owner_thread(Core::EmuThreadHandle::InvalidHandle()) {}
+
+ bool IsLockedByCurrentThread() const {
+ return this->owner_thread == kernel.GetCurrentEmuThreadID();
+ }
+
+ void Lock() {
+ if (this->IsLockedByCurrentThread()) {
+ /* If we already own the lock, we can just increment the count. */
+ ASSERT(this->lock_count > 0);
+ this->lock_count++;
+ } else {
+ /* Otherwise, we want to disable scheduling and acquire the spinlock. */
+ SchedulerType::DisableScheduling(kernel);
+ this->spin_lock.lock();
+
+ /* For debug, ensure that our state is valid. */
+ ASSERT(this->lock_count == 0);
+ ASSERT(this->owner_thread == Core::EmuThreadHandle::InvalidHandle());
+
+ /* Increment count, take ownership. */
+ this->lock_count = 1;
+ this->owner_thread = kernel.GetCurrentEmuThreadID();
+ }
+ }
+
+ void Unlock() {
+ ASSERT(this->IsLockedByCurrentThread());
+ ASSERT(this->lock_count > 0);
+
+ /* Release an instance of the lock. */
+ if ((--this->lock_count) == 0) {
+ /* We're no longer going to hold the lock. Take note of what cores need scheduling. */
+ const u64 cores_needing_scheduling =
+ SchedulerType::UpdateHighestPriorityThreads(kernel);
+ Core::EmuThreadHandle leaving_thread = owner_thread;
+
+ /* Note that we no longer hold the lock, and unlock the spinlock. */
+ this->owner_thread = Core::EmuThreadHandle::InvalidHandle();
+ this->spin_lock.unlock();
+
+ /* Enable scheduling, and perform a rescheduling operation. */
+ SchedulerType::EnableScheduling(kernel, cores_needing_scheduling, leaving_thread);
+ }
+ }
+};
+
+} // namespace Kernel