jos/user/stresssched.c
Anish Athalye da1f8392b1 Lab 4
2018-10-08 21:32:14 -07:00

40 lines
776 B
C

#include <inc/lib.h>
volatile int counter;
void
umain(int argc, char **argv)
{
int i, j;
int seen;
envid_t parent = sys_getenvid();
// Fork several environments
for (i = 0; i < 20; i++)
if (fork() == 0)
break;
if (i == 20) {
sys_yield();
return;
}
// Wait for the parent to finish forking
while (envs[ENVX(parent)].env_status != ENV_FREE)
asm volatile("pause");
// Check that one environment doesn't run on two CPUs at once
for (i = 0; i < 10; i++) {
sys_yield();
for (j = 0; j < 10000; j++)
counter++;
}
if (counter != 10*10000)
panic("ran on two CPUs at once (counter is %d)", counter);
// Check that we see environments running on different CPUs
cprintf("[%08x] stresssched on CPU %d\n", thisenv->env_id, thisenv->env_cpunum);
}