DOS/task.c at main · PythonCoders45/DOS · GitHub

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#include"types.h"

externvoid*kmalloc(size_tsize);

typedefstructTask {
uint32_tid;
uint32_tesp; // Stack pointer register
uint32_tebp; // Base pointer register
uint32_teip; // Instruction pointer register
structTask*next; // Pointer to next task in linked list
} Task;

staticTask*current_task=NULL;
staticTask*task_list_head=NULL;
staticuint32_tnext_pid=1;

/**
 * @brief Creates a new concurrent process with its own dedicated stack space
 */
Task*create_task(void (*entry_point)(void)) {
Task*new_task= (Task*)kmalloc(sizeof(Task));
new_task->id=next_pid++;

// Allocate 16 KB stack for the new task
uint32_tstack= (uint32_t)kmalloc(16384) +16384;

// Set up initial execution registers
new_task->esp=stack;
new_task->ebp=stack;
new_task->eip= (uint32_t)entry_point;
new_task->next=NULL;

// Add to circular linked list
if (!task_list_head) {
task_list_head=new_task;
new_task->next=new_task; // Circular reference
 } else {
Task*temp=task_list_head;
while (temp->next!=task_list_head) {
temp=temp->next;
 }
temp->next=new_task;
new_task->next=task_list_head;
 }

returnnew_task;
}

/**
 * @brief Switches execution to the next process in the queue (Round-Robin)
 */
voidschedule(void) {
if (!current_task) {
current_task=task_list_head;
return;
 }

// Switch to next task pointer
current_task=current_task->next;
}