49 lines
915 B
C
49 lines
915 B
C
|
#include <signal.h>
|
||
|
|
#include <unistd.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
|
||
|
|
static void sig_int(int);
|
||
|
|
|
||
|
|
int main(void) {
|
||
|
|
sigset_t newmask, oldmask, waitmask;
|
||
|
|
|
||
|
|
printf("program start\n");
|
||
|
|
|
||
|
|
if(signal(SIGINT, sig_int) == SIG_ERR) {
|
||
|
|
printf("signal(SIGINT) error\n");
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
sigemptyset(&waitmask);
|
||
|
|
sigaddset(&waitmask, SIGUSR1);
|
||
|
|
sigemptyset(&newmask);
|
||
|
|
sigaddset(&newmask, SIGINT);
|
||
|
|
|
||
|
|
if(sigprocmask(SIG_BLOCK, &newmask, &oldmask) < 0) {
|
||
|
|
printf("SIG_BLOCK error\n");
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
printf("in critical region\n");
|
||
|
|
|
||
|
|
if(sigsuspend(&waitmask) != -1) {
|
||
|
|
printf("sigsuspend error\n");
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
printf("after return from sigsuspend\n");
|
||
|
|
|
||
|
|
if(sigprocmask(SIG_SETMASK, &oldmask, NULL) < 0){
|
||
|
|
printf("SIG_SETMASK error\n");
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
|
||
|
|
printf("program exit\n");
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void sig_int(int signo) {
|
||
|
|
printf("caught sigint = %d\n", signo);
|
||
|
|
}
|