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// MIT License, Copyright (c) 2020 Marvin Borner
#include <assert.h>
#include <boot.h>
#include <cpu.h>
#include <interrupts.h>
#include <list.h>
#include <load.h>
#include <mem.h>
#include <print.h>
#include <proc.h>
#include <str.h>
#include <timer.h>
u32 pid = 0;
u32 quantum = 0;
struct list *proc_list;
struct node *current;
// TODO: Use less memcpy and only copy relevant registers
void scheduler(struct regs *regs)
{
timer_handler();
if (quantum == 0) {
quantum = PROC_QUANTUM;
} else {
quantum--;
return;
}
if (current && ((struct proc *)current->data)->state == PROC_RESOLVED) {
memcpy(regs, &((struct proc *)current->data)->regs_backup, sizeof(struct regs));
((struct proc *)current->data)->state = PROC_DEFAULT;
}
if (current)
memcpy(&((struct proc *)current->data)->regs, regs, sizeof(struct regs));
if (current && current->next)
current = current->next;
else
current = proc_list->head;
while (!current) {
if (!current->next || !current->next->data) {
assert(proc_list->head);
current = proc_list->head;
} else {
current = current->next;
}
}
memcpy(regs, &((struct proc *)current->data)->regs, sizeof(struct regs));
if (regs->cs != GDT_USER_CODE_OFFSET) {
regs->gs = GDT_USER_DATA_OFFSET;
regs->fs = GDT_USER_DATA_OFFSET;
regs->es = GDT_USER_DATA_OFFSET;
regs->ds = GDT_USER_DATA_OFFSET;
regs->ss = GDT_USER_DATA_OFFSET;
regs->cs = GDT_USER_CODE_OFFSET;
regs->eflags = EFLAGS_ALWAYS | EFLAGS_INTERRUPTS;
}
struct proc *proc = current->data;
if (proc->state == PROC_DEFAULT && proc->events && proc->events->head) {
struct proc_event *proc_event = proc->events->head->data;
printf("Event %d for pid %d\n", proc_event->desc->id, proc->pid);
memcpy(&proc->regs_backup, regs, sizeof(struct regs));
regs->eip = (u32)proc_event->desc->func;
quantum = PROC_QUANTUM;
proc->state = PROC_IN_EVENT;
regs->useresp += 4;
((u32 *)regs->useresp)[1] = (u32)proc_event->data; // Huh
list_remove(proc->events, proc->events->head);
}
/* printf("{%d}", ((struct proc *)current->data)->pid); */
}
void proc_print()
{
struct node *node = proc_list->head;
printf("\nPROCESSES\n");
struct proc *proc;
while (node && (proc = node->data)) {
printf("Process %d: %s\n", proc->pid, proc->name);
node = node->next;
}
printf("\n");
}
struct proc *proc_current()
{
return current ? current->data : NULL;
}
void proc_send(struct proc *src, struct proc *dest, enum message_type type, void *data)
{
assert(src && dest);
struct proc_message *msg = malloc(sizeof(*msg));
msg->src = src;
msg->dest = dest;
msg->msg = malloc(sizeof(struct message));
msg->msg->src = src->pid;
msg->msg->type = type;
msg->msg->data = data;
list_add(dest->messages, msg);
}
struct proc_message *proc_receive(struct proc *proc)
{
if (proc->messages && proc->messages->head) {
struct proc_message *msg = proc->messages->head->data;
list_remove(proc->messages, proc->messages->head);
return msg;
} else {
return NULL;
}
}
void proc_resolve(struct proc *proc)
{
proc->state = PROC_RESOLVED;
quantum = 0;
sti();
hlt();
}
struct proc *proc_from_pid(u32 pid)
{
struct node *iterator = proc_list->head;
do {
if (((struct proc *)iterator->data)->pid == pid) {
return iterator->data;
}
} while ((iterator = iterator->next) != NULL);
return NULL;
}
void proc_exit(struct proc *proc, int status)
{
assert(proc);
printf("Process %d exited with status %d\n", proc->pid, status);
struct node *iterator = proc_list->head;
do {
if (iterator->data == proc) {
list_remove(proc_list, iterator);
break;
}
} while ((iterator = iterator->next) != NULL);
quantum = 0; // TODO: Add quantum to each process struct?
sti();
hlt();
}
// TODO: More instant yield
void proc_yield()
{
quantum = 0;
}
struct proc *proc_make()
{
struct proc *proc = malloc(sizeof(*proc));
proc->pid = pid++;
proc->events = list_new();
proc->messages = list_new();
proc->state = PROC_DEFAULT;
if (current)
list_add(proc_list, proc);
return proc;
}
extern void proc_jump_userspace();
u32 _esp, _eip;
void proc_init()
{
if (proc_list)
return;
cli();
irq_install_handler(0, scheduler);
proc_list = list_new();
struct node *new = list_add(proc_list, proc_make());
bin_load("/init", new->data);
_eip = ((struct proc *)new->data)->regs.eip;
_esp = ((struct proc *)new->data)->regs.useresp;
int argc = 2;
char **argv = malloc(sizeof(*argv) * (argc + 1));
argv[0] = "init";
argv[1] = (char *)boot_passed->vbe;
argv[2] = NULL;
((u32 *)_esp)[0] = argc; // First argument (argc)
((u32 *)_esp)[1] = (u32)argv; // Second argument (argv)
proc_jump_userspace();
while (1) {
};
}
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