58 lines
2.1 KiB
C
58 lines
2.1 KiB
C
#pragma once
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// ke_sched.h - Multi-Level Feedback Queue scheduler
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// Three run queues (Low / Normal / High). IRQ 0 drives KeSchedulerTick.
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#include <ke_thread.h>
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#define SCHED_TICK_MS 10u
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#define SCHED_HIGH_QUANTUM_TICKS 2u
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#define SCHED_NORMAL_QUANTUM_TICKS 4u
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#define SCHED_LOW_QUANTUM_TICKS 8u
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#define SCHED_DEMOTE_AFTER_BURST_TICKS 16u
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#define SCHED_AGING_INTERVAL_TICKS 100u
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typedef struct KE_SCHED_STATS {
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uint64_t Ticks;
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uint64_t ContextSwitches;
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uint64_t KeepCurrentDecisions;
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uint64_t IdleSelections;
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uint64_t Demotions;
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uint64_t AgingPromotions;
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uint64_t QuantumExpirations;
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uint64_t PriorityPreemptions;
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uint64_t VoluntaryBlocks;
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uint64_t CpuBurstDemotions;
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} KE_SCHED_STATS;
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// Called once by KernelMain before any threads are created.
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void KeInitializeScheduler(void);
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// Add / remove a thread from the run queues.
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void KeReadyThread(THREAD* thread);
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void KeUnreadyThread(THREAD* thread);
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// Called from the timer ISR every SCHED_TICK_MS. This performs timer
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// accounting and requests a reschedule only when the current thread has
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// exhausted its scheduler budget, or when idle work becomes available. The
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// actual context switch happens from
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// KiExitInterrupt after the IRQ handler has returned and EOI has been sent.
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void KeSchedulerTick(void);
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// Internal scheduler hooks used by the interrupt-exit path. KiRequestReschedule
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// is cheap and can be called from interrupt context. KiScheduleFromInterrupt
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// consumes the pending request and performs the context switch, if needed.
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void KiRequestReschedule(void);
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int KiIsReschedulePending(void);
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void KiScheduleFromInterrupt(void);
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void KiSchedulerNoteVoluntaryBlock(THREAD* thread);
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// Voluntarily yield the CPU. Picks the next runnable thread immediately.
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__declspec(dllexport) void KeYield(void);
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void KeGetSchedulerStats(KE_SCHED_STATS* out);
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// Returns the thread currently running on this CPU (reads GS:[0]).
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THREAD* KeGetCurrentThread(void);
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// Set the current-thread GS slot. Called once per CPU at boot.
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void KeSetCurrentThread(THREAD* thread);
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