Files
pepperOS/src/sched/process.c

122 lines
2.9 KiB
C

#include <stddef.h>
#include "process.h"
#include "mem/heap/kheap.h"
#include "kernel.h"
#include "string/string.h"
#include "mem/gdt/gdt.h"
struct process_t* processes_list;
struct process_t* current_process;
size_t next_free_pid = 0;
void process_init()
{
processes_list = NULL;
current_process = NULL;
}
// Only for debug
void process_display_list(struct process_t* processes_list)
{
int process_view_id = 0;
struct process_t* tmp = processes_list;
while (tmp != NULL)
{
DEBUG("{%d: %p} -> ", process_view_id, tmp);
tmp = tmp->next;
process_view_id++;
}
DEBUG("NULL");
}
struct process_t* process_create(char* name, void(*function)(void*), void* arg)
{
CLEAR_INTERRUPTS;
struct process_t* proc = (struct process_t*)kmalloc(sizeof(struct process_t));
struct cpu_status_t* ctx = (struct cpu_status_t*)kmalloc(sizeof(struct cpu_status_t));
// No more memory?
if (!proc) return NULL;
if (!ctx) return NULL;
strncpy(proc->name, name, PROCESS_NAME_MAX);
proc->pid = next_free_pid++;
proc->status = READY;
proc->context = ctx;
proc->context->iret_ss = KERNEL_DATA_SEGMENT; // process will live in kernel mode
proc->context->iret_rsp = (uint64_t)kalloc_stack();
proc->context->iret_flags = 0x202; //bit 2 and 9 set (Interrupt Flag)
proc->context->iret_cs = KERNEL_CODE_SEGMENT;
proc->context->iret_rip = (uint64_t)function; // beginning of executable code
proc->context->rdi = (uint64_t)arg; // 1st arg is in rdi (as per x64 calling convention)
proc->context->rbp = 0;
proc->next = 0;
process_add(&processes_list, proc);
SET_INTERRUPTS;
return proc;
}
void process_add(struct process_t** processes_list, struct process_t* process)
{
if (!process) return;
process->next = NULL;
if (*processes_list == NULL)
{
// List is empty
*processes_list = process;
return;
}
struct process_t* tmp = *processes_list;
while (tmp->next != NULL)
{
tmp = tmp->next;
}
// We're at last process before NULL
tmp->next = process;
// process->next = NULL;
}
void process_delete(struct process_t** processes_list, struct process_t* process)
{
if (!processes_list || !*processes_list || !process) return;
if (*processes_list == process)
{
// process to delete is at head
*processes_list = process->next;
process->next = NULL;
kfree(process);
return;
}
struct process_t* tmp = *processes_list;
while (tmp->next && tmp->next != process)
{
tmp = tmp->next;
}
if (tmp->next == NULL)
{
// Didn't find the process
return;
}
// We're at process before the one we want to delete
tmp->next = process->next;
process->next = NULL;
kfree(process);
}
struct process_t* process_get_next(struct process_t* process)
{
if (!process) return NULL;
return process->next;
}