linux alarm us定时,alarm信号定时运行程序 Linux

alarm信号定时运行程序 Linux

#include

#include

void sigprint(int n)

{

printf("2 seconds past.\n");

int i ;

for(i = 0;i<1000;i++)

for(i = 0;i<1000;i++)

for(i = 0;i<1000;i++)

for(i = 0;i<1000;i++)

;

}

int mysleep(int nsec)

{

int unleft;

sigset_t newmask,oldmask,susmask;

struct sigaction newact,oldact;

newact.sa_handler = sigprint;

sigemptyset(&newact.sa_mask);

newact.sa_flags = 0;

sigaction(SIGALRM,&newact,&oldact);

sigemptyset(&newmask);

sigaddset(&newmask,SIGALRM);

sigprocmask(SIG_BLOCK,&newmask,&oldmask);

alarm(nsec);

susmask = oldmask;

sigdelset(&susmask,SIGALRM);

sigsuspend(&susmask);

unleft = alarm(0);

sigaction(SIGALRM,&oldact,NULL);

sigprocmask(SIGALRM,&oldmask,NULL);

return unleft ;

}

int main(void)

{

int i = 10;

while(i){

mysleep(2);

i--;

}

return 0;

}