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#include "task.h"
#include <core/sys.h>
#include <core/monitor.h>
#include <mem/mem.h>
#include "timer.h"
#define KSTACKSIZE 0x8000
//Static routines for handling threads exiting and all cleanup
static void thread_exit_stackJmp(uint32_t reason);
static void thread_exit2(uint32_t reason);
static void thread_delete(struct thread *th);
static void process_delete(struct process *pr);
//From task_.asm
extern uint32_t read_eip();
extern void task_idle(void*);
static uint32_t thread_runnable(struct thread *th);
static uint32_t nextpid = 1;
struct process *processes = 0, *kernel_process;
struct thread *threads = 0, *current_thread = 0, *idle_thread;
uint32_t tasking_tmpStack[0x4000];
void tasking_init() {
cli();
kernel_process = kmalloc(sizeof(struct process)); //This process must be hidden to users
kernel_process->pid = kernel_process->uid = kernel_process->threads = 0;
kernel_process->privilege = PL_KERNEL;
kernel_process->parent = kernel_process;
kernel_process->pagedir = kernel_pagedir;
kernel_process->next = 0;
current_thread = 0;
idle_thread = thread_new(kernel_process, task_idle, 0);
threads = 0; //Do not include idle thread in threads
sti();
monitor_write("Tasking set up\n");
}
static struct thread *thread_next() {
if (current_thread == 0 || current_thread == idle_thread) current_thread = threads;
struct thread *ret = current_thread;
while (1) {
ret = ret->next;
if (ret == 0) ret = threads;
if (thread_runnable(ret)) {
return ret;
}
if (ret == current_thread) return idle_thread;
}
}
void tasking_switch() {
if (threads == 0) PANIC("No more threads to run !");
asm volatile("cli");
uint32_t esp, ebp, eip;
asm volatile("mov %%esp, %0" : "=r"(esp));
asm volatile("mov %%ebp, %0" : "=r"(ebp));
eip = read_eip();
if (eip == 0x12345) {
return;
}
if (current_thread != 0) {
current_thread->esp = esp;
current_thread->ebp = ebp;
current_thread->eip = eip;
}
current_thread = thread_next();
asm volatile(" \
mov %0, %%ebp; \
mov %1, %%esp; \
mov %2, %%ecx; \
mov $0x12345, %%eax; \
jmp *%%ecx;"
: : "r"(current_thread->ebp), "r"(current_thread->esp), "r"(current_thread->eip));
}
void tasking_updateKernelPagetable(uint32_t idx, struct page_table *table, uint32_t tablephysical) {
if (idx < 896) return;
struct process* it = processes;
while (it != 0) {
it->pagedir->tables[idx] = table;
it->pagedir->tablesPhysical[idx] = tablephysical;
it = it->next;
}
}
uint32_t tasking_handleException(struct registers *regs) {
if (current_thread == 0) return 0; //No tasking yet
monitor_write("\n(task.c:99) Unhandled exception : ");
char *exception_messages[] = {"Division By Zero","Debug","Non Maskable Interrupt","Breakpoint",
"Into Detected Overflow","Out of Bounds","Invalid Opcode","No Coprocessor", "Double Fault",
"Coprocessor Segment Overrun","Bad TSS","Segment Not Present","Stack Fault","General Protection Fault",
"Page Fault","Unknown Interrupt","Coprocessor Fault","Alignment Check","Machine Check"};
monitor_write(exception_messages[regs->int_no]);
monitor_write(" at "); monitor_writeHex(regs->eip);
monitor_write(" >>> Thread exiting.\n");
thread_exit_stackJmp(EX_TH_EXCEPTION);
PANIC("This should never have happened. Please report this.");
}
void thread_sleep(uint32_t msecs) {
if (current_thread == 0) return;
current_thread->state = TS_SLEEPING;
current_thread->timeWait = timer_time() + msecs;
asm volatile("int $64" : : "a"(1));
}
void thread_exit2(uint32_t reason) { //See EX_TH_* defines in task.h
/*
* if reason == EX_TH_NORMAL, it is just one thread exiting because it has to
* if reason == EX_TH_EXCEPTION, it is just one thread exiting because of an exception
* if reason is none of the two cases above, it is the whole process exiting (with error code = reason)
*/
struct thread *th = current_thread;
struct process *pr = th->process;
if ((reason == EX_TH_NORMAL || reason == EX_TH_EXCEPTION) && pr->threads > 1) {
thread_delete(th);
} else {
process_delete(pr);
}
sti();
tasking_switch();
}
void thread_exit_stackJmp(uint32_t reason) {
uint32_t *stack;
cli();
stack = tasking_tmpStack + 0x4000;
stack--; *stack = reason;
stack--; *stack = 0;
asm volatile(" \
mov %0, %%esp; \
mov %1, %%ebp; \
mov %2, %%ecx; \
mov %3, %%cr3; \
jmp *%%ecx;" : :
"r"(stack), "r"(stack), "r"(thread_exit2), "r"(kernel_pagedir->physicalAddr));
}
void thread_exit() {
thread_exit_stackJmp(EX_TH_NORMAL);
}
void process_exit(uint32_t retval) {
if (retval == EX_TH_NORMAL || retval == EX_TH_EXCEPTION) retval = EX_PR_EXCEPTION;
thread_exit_stackJmp(retval);
}
static uint32_t thread_runnable(struct thread *t) {
if (t->state == TS_RUNNING) return 1;
if (t->state == TS_SLEEPING && timer_time() >= t->timeWait) return 1;
return 0;
}
static void thread_run(struct thread *thread, thread_entry entry_point, void *data) {
pagedir_switch(thread->process->pagedir); //TODO : take into account privilege level
asm volatile("sti");
entry_point(data);
thread_exit(0);
}
struct thread *thread_new(struct process *proc, thread_entry entry_point, void *data) {
struct thread *t = kmalloc(sizeof(struct thread));
t->process = proc;
proc->threads++;
t->kernelStack_addr = kmalloc(KSTACKSIZE);
t->kernelStack_size = KSTACKSIZE;
uint32_t *stack = (uint32_t*)((size_t)t->kernelStack_addr + t->kernelStack_size);
//Pass parameters
stack--; *stack = (uint32_t)data;
stack--; *stack = (uint32_t)entry_point;
stack--; *stack = (uint32_t)t;
stack--; *stack = 0;
t->esp = (uint32_t)stack;
t->ebp = t->esp + 8;
t->eip = (uint32_t)thread_run;
t->state = TS_RUNNING;
if (threads == 0) {
threads = t;
} else {
struct thread *i = threads;
while (i->next != 0) i = i->next;
i->next = t;
}
return t;
}
struct process *process_new(struct process* parent, uint32_t uid, uint32_t privilege) {
struct process* p = kmalloc(sizeof(struct process));
p->pid = (nextpid++);
p->uid = uid;
p->threads = 0;
p->privilege = privilege;
p->parent = parent;
p->pagedir = pagedir_new();
p->next = processes;
processes = p;
return p;
}
static void thread_delete(struct thread *th) {
kfree(th->kernelStack_addr);
th->process->threads--;
if (threads == th) {
threads = th->next;
} else {
struct thread *it = threads;
while (it->next != th && it->next != 0) it = it->next;
if (it->next == th) it->next = th->next;
}
kfree(th);
}
static void process_delete(struct process *pr) {
struct thread *it;
while (threads != 0 && threads->process == pr) thread_delete(threads);
it = threads;
while (it != 0) {
while (it->next->process == pr) thread_delete(it->next);
it = it->next;
}
pagedir_delete(pr->pagedir);
if (processes == pr) {
processes = pr->next;
} else {
struct process *it = processes;
while (it != 0 && it->next != pr) it = it->next;
if (it != 0 && it->next == pr) it->next = pr->next;
}
kfree(pr);
}
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