70 lines
1.4 KiB
C
70 lines
1.4 KiB
C
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#include <signal.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <stdlib.h>
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void catcher(int sig) {
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puts("Got SIGUSR1");
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}
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int check_pending(int sig, char *signame) {
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sigset_t sigset;
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if(sigpending(&sigset) != 0){
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perror("sigpending() error\n");
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exit(1);
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}
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if(sigismember(&sigset, sig)){
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printf("a %s (%d) signal is pending\n", signame, sig);
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return 1;
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} else {
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printf("no %s (%d) signals are pending\n", signame, sig);
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return 0;
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}
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}
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int main(int argc, char *argv[]) {
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struct sigaction sigact;
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sigset_t sigset;
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sigemptyset(&sigact.sa_mask);
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sigact.sa_flags = 0;
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sigact.sa_handler = catcher;
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if(sigaction(SIGUSR1, &sigact, NULL) != 0){
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perror("sigaction() error\n");
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return 2;
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}
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printf("Calling sigprocmask to block SIGUSR1...\n");
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sigemptyset(&sigset);
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sigaddset(&sigset, SIGUSR1);
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if (sigprocmask(SIG_SETMASK, &sigset, NULL) != 0){
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perror("sigprocmask() error\n");
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return 3;
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}
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printf("SIGUSR1 signals are now blocked\n");
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kill(getpid(), SIGUSR1);
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printf("kill(getpid(), SIGUSR1) DONE\n");
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if(!check_pending(SIGUSR1, "SIGUSR1")){
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printf("FAIL: SIGUSR1 is not pending despite the mask\n");
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return 4;
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}
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printf("Calling sigprocmask to unblock SIGUSR1...\n");
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sigemptyset(&sigset);
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sigprocmask(SIG_SETMASK, &sigset, NULL);
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printf("SIGUSR1 signals are no longer blocked\n");
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if(check_pending(SIGUSR1, "SIGUSR1")){
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printf("FAIL: SIGUSR1 is still pending despite the mask\n");
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return 4;
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}
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return 0;
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}
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