HariboteOS/day17/timer.c
2021-04-13 23:36:24 +08:00

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#include <stdio.h>
#include "int.h"
#include "io.h"
#include "task.h"
#include "timer.h"
struct TimerCtl timerctl;
void init_pit(void) {
io_out8(PIT_CTRL, 0x34);
io_out8(PIT_CNT0, 0x9c);
io_out8(PIT_CNT0, 0x2e);
for (int i = 0; i < MAX_TIMER; i++) {
timerctl.timers0[i].flags = 0;
}
struct Timer *t = timer_alloc();
t->timeout = 0xffffffff;
t->flags = TIMER_FLAGS_USING;
t->next = NULL;
timerctl.count = 0;
timerctl.t0 = t;
timerctl.next = 0xffffffff;
}
struct Timer *timer_alloc(void) {
for (int i = 0; i < MAX_TIMER; i++) {
if (timerctl.timers0[i].flags == 0) {
timerctl.timers0[i].flags = TIMER_FLAGS_ALLOC;
return &timerctl.timers0[i];
}
}
return NULL;
}
void timer_free(struct Timer *timer) { timer->flags = 0; }
void timer_init(struct Timer *timer, struct FIFO32 *fifo, int data) {
timer->fifo = fifo;
timer->data = data;
}
void timer_set_timer(struct Timer *timer, unsigned int timeout) {
int eflags;
struct Timer *t, *s;
timer->timeout = timeout + timerctl.count;
timer->flags = TIMER_FLAGS_USING;
eflags = io_load_eflags();
io_cli();
t = timerctl.t0;
if (timer->timeout <= t->timeout) {
timerctl.t0 = timer;
timer->next = t;
timerctl.next = timer->timeout;
io_store_eflags(eflags);
return;
}
// 搜索插入未知
for (;;) {
s = t;
t = t->next;
if (timer->timeout <= t->timeout) {
s->next = timer;
timer->next = t;
io_store_eflags(eflags);
return;
}
}
}
void int_handler20(int *esp) {
char ts = 0;
io_out8(PIC0_OCW2, 0x60); // 接收IRQ-00信号通知PIC
timerctl.count++;
if (timerctl.next > timerctl.count) {
return;
}
struct Timer *timer = timerctl.t0;
for (;;) {
// timers的定时器都处于动作中所以不确认flags
if (timer->timeout > timerctl.count) {
break;
}
// 超时
timer->flags = TIMER_FLAGS_ALLOC;
if (timer != task_timer) {
fifo32_put(timer->fifo, timer->data);
} else {
ts = 1;
}
timer = timer->next;
}
timerctl.t0 = timer;
timerctl.next = timer->timeout;
if (ts) {
task_switch();
}
}