Files
MIT6.828_OS/lab/kern/time.c
2019-07-17 16:08:06 +08:00

27 lines
359 B
C

#include <kern/time.h>
#include <inc/assert.h>
static unsigned int ticks;
void
time_init(void)
{
ticks = 0;
}
// This should be called once per timer interrupt. A timer interrupt
// fires every 10 ms.
void
time_tick(void)
{
ticks++;
if (ticks * 10 < ticks)
panic("time_tick: time overflowed");
}
unsigned int
time_msec(void)
{
return ticks * 10;
}