suyu/src/core/hle/kernel/k_scheduler.h
Lioncash 9a07ed53eb core: Make variable shadowing a compile-time error
Now that we have most of core free of shadowing, we can enable the
warning as an error to catch anything that may be remaining and also
eliminate this class of logic bug entirely.
2021-05-16 03:43:16 -04:00

204 lines
6.6 KiB
C++

// Copyright 2020 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <atomic>
#include "common/common_types.h"
#include "core/hle/kernel/global_scheduler_context.h"
#include "core/hle/kernel/k_priority_queue.h"
#include "core/hle/kernel/k_scheduler_lock.h"
#include "core/hle/kernel/k_scoped_lock.h"
#include "core/hle/kernel/k_spin_lock.h"
namespace Common {
class Fiber;
}
namespace Core {
class System;
}
namespace Kernel {
class KernelCore;
class KProcess;
class SchedulerLock;
class KThread;
class KScheduler final {
public:
explicit KScheduler(Core::System& system_, s32 core_id_);
~KScheduler();
/// Reschedules to the next available thread (call after current thread is suspended)
void RescheduleCurrentCore();
/// Reschedules cores pending reschedule, to be called on EnableScheduling.
static void RescheduleCores(KernelCore& kernel, u64 cores_pending_reschedule);
/// The next two are for SingleCore Only.
/// Unload current thread before preempting core.
void Unload(KThread* thread);
/// Reload current thread after core preemption.
void Reload(KThread* thread);
/// Gets the current running thread
[[nodiscard]] KThread* GetCurrentThread() const;
/// Returns true if the scheduler is idle
[[nodiscard]] bool IsIdle() const {
return GetCurrentThread() == idle_thread;
}
/// Gets the timestamp for the last context switch in ticks.
[[nodiscard]] u64 GetLastContextSwitchTicks() const;
[[nodiscard]] bool ContextSwitchPending() const {
return state.needs_scheduling.load(std::memory_order_relaxed);
}
void Initialize();
void OnThreadStart();
[[nodiscard]] std::shared_ptr<Common::Fiber>& ControlContext() {
return switch_fiber;
}
[[nodiscard]] const std::shared_ptr<Common::Fiber>& ControlContext() const {
return switch_fiber;
}
[[nodiscard]] u64 UpdateHighestPriorityThread(KThread* highest_thread);
/**
* Takes a thread and moves it to the back of the it's priority list.
*
* @note This operation can be redundant and no scheduling is changed if marked as so.
*/
static void YieldWithoutCoreMigration(KernelCore& kernel);
/**
* Takes a thread and moves it to the back of the it's priority list.
* Afterwards, tries to pick a suggested thread from the suggested queue that has worse time or
* a better priority than the next thread in the core.
*
* @note This operation can be redundant and no scheduling is changed if marked as so.
*/
static void YieldWithCoreMigration(KernelCore& kernel);
/**
* Takes a thread and moves it out of the scheduling queue.
* and into the suggested queue. If no thread can be scheduled afterwards in that core,
* a suggested thread is obtained instead.
*
* @note This operation can be redundant and no scheduling is changed if marked as so.
*/
static void YieldToAnyThread(KernelCore& kernel);
static void ClearPreviousThread(KernelCore& kernel, KThread* thread);
/// Notify the scheduler a thread's status has changed.
static void OnThreadStateChanged(KernelCore& kernel, KThread* thread, ThreadState old_state);
/// Notify the scheduler a thread's priority has changed.
static void OnThreadPriorityChanged(KernelCore& kernel, KThread* thread, s32 old_priority);
/// Notify the scheduler a thread's core and/or affinity mask has changed.
static void OnThreadAffinityMaskChanged(KernelCore& kernel, KThread* thread,
const KAffinityMask& old_affinity, s32 old_core);
static bool CanSchedule(KernelCore& kernel);
static bool IsSchedulerUpdateNeeded(const KernelCore& kernel);
static void SetSchedulerUpdateNeeded(KernelCore& kernel);
static void ClearSchedulerUpdateNeeded(KernelCore& kernel);
static void DisableScheduling(KernelCore& kernel);
static void EnableScheduling(KernelCore& kernel, u64 cores_needing_scheduling);
[[nodiscard]] static u64 UpdateHighestPriorityThreads(KernelCore& kernel);
private:
friend class GlobalSchedulerContext;
/**
* Takes care of selecting the new scheduled threads in three steps:
*
* 1. First a thread is selected from the top of the priority queue. If no thread
* is obtained then we move to step two, else we are done.
*
* 2. Second we try to get a suggested thread that's not assigned to any core or
* that is not the top thread in that core.
*
* 3. Third is no suggested thread is found, we do a second pass and pick a running
* thread in another core and swap it with its current thread.
*
* returns the cores needing scheduling.
*/
[[nodiscard]] static u64 UpdateHighestPriorityThreadsImpl(KernelCore& kernel);
[[nodiscard]] static KSchedulerPriorityQueue& GetPriorityQueue(KernelCore& kernel);
void RotateScheduledQueue(s32 cpu_core_id, s32 priority);
void Schedule() {
ASSERT(GetCurrentThread()->GetDisableDispatchCount() == 1);
this->ScheduleImpl();
}
/// Switches the CPU's active thread context to that of the specified thread
void ScheduleImpl();
/// When a thread wakes up, it must run this through it's new scheduler
void SwitchContextStep2();
/**
* Called on every context switch to update the internal timestamp
* This also updates the running time ticks for the given thread and
* process using the following difference:
*
* ticks += most_recent_ticks - last_context_switch_ticks
*
* The internal tick timestamp for the scheduler is simply the
* most recent tick count retrieved. No special arithmetic is
* applied to it.
*/
void UpdateLastContextSwitchTime(KThread* thread, KProcess* process);
static void OnSwitch(void* this_scheduler);
void SwitchToCurrent();
KThread* prev_thread{};
std::atomic<KThread*> current_thread{};
KThread* idle_thread{};
std::shared_ptr<Common::Fiber> switch_fiber{};
struct SchedulingState {
std::atomic<bool> needs_scheduling{};
bool interrupt_task_thread_runnable{};
bool should_count_idle{};
u64 idle_count{};
KThread* highest_priority_thread{};
void* idle_thread_stack{};
};
SchedulingState state;
Core::System& system;
u64 last_context_switch_time{};
const s32 core_id;
KSpinLock guard{};
};
class [[nodiscard]] KScopedSchedulerLock : KScopedLock<GlobalSchedulerContext::LockType> {
public:
explicit KScopedSchedulerLock(KernelCore & kernel);
~KScopedSchedulerLock();
};
} // namespace Kernel