forked from xamidev/pepperOS
78 lines
2.1 KiB
C
78 lines
2.1 KiB
C
/*
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* @author xamidev <xamidev@riseup.net>
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* @brief Round-robin scheduler
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* @license GPL-3.0-only
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*/
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#include "kernel.h"
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#include "process.h"
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#include "mem/paging/paging.h"
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#include <stdint.h>
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#include "io/serial/serial.h"
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extern struct process_t* processes_list;
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extern struct process_t* current_process;
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extern struct process_t* idle_proc;
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/*
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* scheduler_init - Choose the first process
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*/
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void scheduler_init()
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{
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current_process = processes_list;
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}
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/*
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* scheduler_schedule - Main scheduling routine
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* @context: CPU context of previous process
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*
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* Chooses the next process that we should run.
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* The routine is executed every SCHEDULER_QUANTUM ticks.
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*
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* Return:
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* <context> - CPU context for next process
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*/
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struct cpu_status_t* scheduler_schedule(struct cpu_status_t* context)
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{
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if (context == NULL) {
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panic(NULL, "Scheduler called with NULL context");
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}
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if (current_process == NULL) {
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// If no more processes, then set IDLE as the current process, that's it.
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current_process = idle_proc;
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}
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if (current_process == idle_proc && current_process->next == NULL)
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{
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return idle_proc->context;
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}
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current_process->context = context;
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//current_process->status = READY;
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for (;;) {
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struct process_t* prev_process = current_process;
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if (current_process->next != NULL) {
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current_process = current_process->next;
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} else {
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current_process = processes_list;
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}
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if (current_process != NULL && current_process->status == DEAD) {
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process_delete(&prev_process, current_process);
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current_process = NULL;
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return idle_proc->context;
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} else {
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current_process->status = RUNNING;
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break;
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}
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}
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DEBUG("current_process={pid=%u, name='%s', root_page_table[virt]=%p}", current_process->pid, current_process->name, current_process->root_page_table);
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load_cr3(VIRT_TO_PHYS((uint64_t)current_process->root_page_table));
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DEBUG("Loaded process PML4 into CR3");
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return current_process->context;
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} |