os/cpu/i386/tasking.c

100 lines
2.4 KiB
C

#include "tasking_helpers.h"
#include "tasking.h"
#include "../tasking.h"
#include "isr.h"
#include "../../libc/stdlib.h"
#include "../../libc/stdio.h"
#include "memory.h"
#include <stdint.h>
#define STACK_PAGES 2
uint32_t next_pid;
static Task* currentTask;
static Task* headTask;
void tasking_init() {
currentTask=NULL;
next_pid=0;
headTask=createTask(NULL);
currentTask=headTask;
}
Task* createTaskEax(void* eip,uint32_t eax) {
Task* task=malloc(sizeof(Task));
task->regs.eax=eax;
task->regs.ebx=0;
task->regs.ecx=0;
task->regs.edx=0;
task->regs.esi=0;
task->regs.edi=0;
asm volatile("pushfl; movl (%%esp), %%eax; movl %%eax, %0; popfl;":"=m"(task->regs.eflags)::"%eax");
task->regs.eip=(uint32_t)eip;
asm volatile("movl %%cr3, %%eax; movl %%eax, %0;":"=m"(task->regs.cr3)::"%eax");
task->regs.esp=(uint32_t)alloc_memory(1);
task->regs.ebp=0;
task->msg_store=NULL;
task->rd=0;
task->wr=0;
task->next=NULL;
task->pid=next_pid;
next_pid++;
if (currentTask) {
currentTask->next=task;
}
return task;
}
Task* createTask(void* eip) {
return createTaskEax(eip,0);
}
void send_msg(uint32_t pid,char* msg) {
for (Task* task=headTask;task!=NULL;task=task->next) {
if (task->pid==pid) {
if (task->msg_store==NULL) {
task->msg_store=malloc(sizeof(char*)*256);
task->sender_store=malloc(sizeof(uint32_t)*256);
}
task->msg_store[task->wr]=msg;
task->sender_store[task->wr]=currentTask->pid;
task->wr++;
if (task->wr==task->rd) {
task->wr--;
}
}
}
}
char* get_msg(uint32_t* sender) {
if (!currentTask->msg_store) {
return NULL;
}
if (currentTask->msg_store[currentTask->rd]==NULL) {
currentTask->rd++;
if (currentTask->msg_store[currentTask->rd]==NULL) {
currentTask->rd--;
return NULL;
}
}
*sender=currentTask->sender_store[currentTask->rd];
char* data=currentTask->msg_store[currentTask->rd];
currentTask->msg_store[currentTask->rd]=NULL;
currentTask->sender_store[currentTask->rd]=0;
currentTask->rd++;
if (currentTask->rd>currentTask->wr) {
currentTask->rd=currentTask->wr-1;
}
return data;
}
void yield() {
Task* task=currentTask->next;
if (!task) {
task=headTask;
}
Task* oldCurr=currentTask;
currentTask=task;
switchTask(&oldCurr->regs, &currentTask->regs);
}