diff options
Diffstat (limited to 'kernel/task.c')
| -rw-r--r-- | kernel/task.c | 223 |
1 files changed, 0 insertions, 223 deletions
diff --git a/kernel/task.c b/kernel/task.c deleted file mode 100644 index 395c196..0000000 --- a/kernel/task.c +++ /dev/null @@ -1,223 +0,0 @@ -// http://hosted.cjmovie.net/TutMultitask.htm -// -// -#define FOOLOS_MODULE_NAME "task" - -#include "kernel.h" -#include "lib/logger/log.h" // logger facilities -#include "mem.h" -#include "timer.h" -#include "asm/x86.h" - -#include "vmem.h" -#include "syscalls.h" -#include "fs/fs.h" -#include "fs/ext2.h" - -#define MAX_TASKS 10 - -static volatile int volatile current_task=-1; - -static volatile struct task_list_struct -{ - volatile int parent; - volatile bool active; - volatile uint32_t esp; // stack pointer of the task; - volatile pdirectory *vmem; // number of virtual memory table to switch to - volatile bool waiting; - volatile bool skipwait; - volatile uint32_t brk; - -}volatile task_list[MAX_TASKS]; - -volatile int add_task(uint32_t esp, uint32_t vmem) -{ - - for(int i=0;i<MAX_TASKS;i++) - { - if(task_list[i].active!=true) - { - - task_list[i].parent=current_task; - task_list[i].vmem=vmem; - task_list[i].esp=esp; - task_list[i].active=true; - task_list[i].waiting=false; - task_list[i].skipwait=false; - task_list[i].brk=task_list[current_task].brk; - return i; - } - } - - panic(FOOLOS_MODULE_NAME,"out of task slots!"); -} - -// -// REMEMBER WE ARE INSIDE AN INTERRUPT HERE - DON'T WASTE TIME! -// -// oldesp - is the adress of the stack pointer when pit_interrupt_handler was entered. -// registers have been pushed with pusha to this old stack. -// -// stack pointer was moved to the 16kb stack we have from multiboot.s -// -// we need to return a NEW stack pointer where popa will get the registers the new task requires -// -static int first=1; -volatile uint32_t my_scheduler(uint32_t oldesp) -{ - - // allows skipping scheduling from gdb - volatile int skippy=0; - if(skippy)return oldesp; - - if(!first) - { - task_list[current_task].esp=oldesp; - } - first=0; - - for(int i=0;i<MAX_TASKS;i++) - { - int pid=(current_task+1+i)%MAX_TASKS; // schedule round robin style - - if(task_list[pid].active && !task_list[pid].waiting) - { -// if(current_task!=pid) -// log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"switch from %d to %d", current_task, pid); - - current_task=pid; - - vmem_set_dir(task_list[pid].vmem); - return task_list[pid].esp; - } - - } - - panic(FOOLOS_MODULE_NAME,"nothing to schedule!"); -} - -// this gets called by our clock interrupt regularly! -volatile uint32_t task_switch_next(uint32_t oldesp) -{ - // check if multitasking has been started - if(current_task<0)return oldesp; - return my_scheduler(oldesp); -} - -//TODO: free vmem too! -//TODO: notify waiting parent when child finished; -volatile uint32_t task_exit(uint32_t oldesp) -{ - - task_list[current_task].active=false; - int parent_pid=task_list[current_task].parent; - - log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"[%d] exit ", current_task); - - if(task_list[parent_pid].active) - { - if(task_list[parent_pid].waiting) - { - - log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"[%d] wake up", parent_pid); - task_list[parent_pid].waiting=false; - } - else - { - log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"[%d] skipwait", parent_pid); - task_list[parent_pid].skipwait=true; - } - - } - - vmem_free_dir(task_list[current_task].vmem); - - return my_scheduler(oldesp); - -} - -volatile uint32_t task_wait(uint32_t oldesp) -{ - log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"[%d] wait", current_task); - if(task_list[current_task].skipwait) - { - task_list[current_task].skipwait=false; - } - else - { - task_list[current_task].waiting=true; - } - return my_scheduler(oldesp); -} - -volatile uint32_t task_fork(uint32_t oldesp) -{ - int pid=add_task(oldesp,vmem_new_space_dir(task_list[current_task].vmem)); - log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"[%d] forked -> [%d] (free blocks remaining: %d )", current_task, pid,mem_get_free_blocks_count()); - return pid; -} - -// init task (root of all other tasks / processes) // -volatile void task_init(pdirectory *dir) -{ - current_task=0; - - // this is our main task on slot 0 - task_list[0].parent=0; - task_list[0].active=true; - task_list[0].waiting=false; - task_list[0].vmem=dir; - task_list[0].esp = kballoc(4); // 0; // will be set by next task_switch_next() call. - - task_list[1].parent=0; - task_list[1].active=true; - task_list[1].waiting=false; - task_list[1].vmem=dir; - task_list[1].esp = kballoc(4); // fresh 16kb stack from here. - - log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"fresh esp on: 0x%08X",1,task_list[1].esp); - log(FOOLOS_MODULE_NAME,FOOLOS_LOG_INFO,"fresh esp on: 0x%08X",0,task_list[0].esp); - - task_pusha(task_list[1].esp); // pusha but to alternative location - task_pusha(task_list[0].esp); // pusha but to alternative location - - /* - current_task=0; - unsigned esp, ebp, eax, ebx, ecx, edx; - - asm( - "movl %%esp, %0;" - "movl %%ebp, %1;" - "movl %%eax, %2;" - "movl %%ebx, %3;" - "movl %%ecx, %4;" - "movl %%edx, %5;" - :"=r"(esp), "=r"(ebp), "=r"(eax), "=r"(ebx), "=r"(ecx), "=r"(edx) - ); - - // TODO: prepare stack so popa get's what it wants! - int i=task_fork(esp); - */ - - // finally enable interrrupts so the scheduler is called (by timer) - x86_sti(); - - // loop until scheduler kicks in and reschedules us... - while(1); - -} - -volatile int task_get_current_pid() -{ - return current_task; -} - -volatile uint32_t task_get_brk() -{ - return task_list[current_task].brk; -} - -volatile void task_set_brk(uint32_t brk) -{ - task_list[current_task].brk=brk; -} |