75 lines
1.6 KiB
C
75 lines
1.6 KiB
C
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#define _POSIX_SOURCE
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#include <stdio.h>
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#include <signal.h>
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#include <time.h>
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#include <unistd.h>
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#include <stdlib.h>
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int SIGUSR1_caught;
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int SIGUSR2_caught;
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void catcher(int signum) {
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switch (signum) {
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case SIGUSR1:
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++SIGUSR1_caught;
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puts("catcher caught SIGUSR1");
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if(SIGUSR2_caught){
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puts("FAIL: SIGUSR2 already caught");
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exit(1);
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}
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break;
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case SIGUSR2:
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++SIGUSR2_caught;
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puts("catcher caught SIGUSR2");
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break;
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default:
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printf("catcher caught unexpected signal %d\n", signum);
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}
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}
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int
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main()
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{
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sigset_t sigset;
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struct sigaction sact;
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time_t t;
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if (fork() == 0) {
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printf("child is %d\n", getpid());
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sleep(10);
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puts("child is sending SIGUSR2 signal - which should be blocked");
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kill(getppid(), SIGUSR2);
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sleep(5);
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puts("child is sending SIGUSR1 signal - which should be caught");
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kill(getppid(), SIGUSR1);
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exit(0);
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}
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sigemptyset(&sact.sa_mask);
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sact.sa_flags = 0;
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sact.sa_handler = catcher;
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if (sigaction(SIGUSR1, &sact, NULL) != 0)
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perror("1st sigaction() error");
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else if (sigaction(SIGUSR2, &sact, NULL) != 0)
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perror("2nd sigaction() error");
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else {
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sigfillset(&sigset);
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sigdelset(&sigset, SIGUSR1);
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time(&t);
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printf("parent is waiting for child to send SIGUSR1 at %s",
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ctime(&t));
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if (sigsuspend(&sigset) == -1)
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perror("sigsuspend() returned -1 as expected");
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time(&t);
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printf("sigsuspend is over at %s", ctime(&t));
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}
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if(SIGUSR1_caught != 1)
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printf("SIGUSR1_caught is %d\n", SIGUSR1_caught);
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if(SIGUSR2_caught != 1)
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printf("SIGUSR2_caught is %d\n", SIGUSR2_caught);
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if(SIGUSR1_caught != 1 || SIGUSR2_caught != 1)
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exit(2);
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exit(0);
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}
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