c - Sending multiple SIGUSR1/SIGUSR2 signals -

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i have following c files: parent & child. parent forks child, , sends multiple sigusr1/sigusr2 child, child receives them , prints output.

receiver.c:

void start_signalset();  void wypisz(int signo) {     if (signo == sigusr1)          printf("received signal1\n");     if (signo == sigusr2)          printf("received signal2\n")     start_signalset(); }  void start_signalset() {     if(signal(sigusr2, wypisz) == sig_err) {  exit(0);  }     if(signal(sigusr1, wypisz) == sig_err) {  exit(0);  } }  int main(int argc, char ** argv) {     start_signalset();     while(is_active) {         sigset_t pusty;         sigemptyset(&pusty);         sigsuspend(&pusty);     }     return 0; }

parent.c:

int main(int argc, char ** argv) {  sigset_t nowy, stary; sigaddset(&nowy, sigusr1); sigaddset(&nowy, sigusr2); sigprocmask(sig_block, &nowy, &stary);  pid_t pid; if((pid = fork()) == -1) {//error handling }     else if(pid == 0)     if(execlp("./receiver", "receiver", null) == -1)         _exit(7);  kill(pid, sigusr1); kill(pid, sigusr1); kill(pid, sigusr1); kill(pid, sigusr2);  return 0; }

the problem in receiver 1 sigusr1 , sigusr2, no matter how many kills sent in parent. sample output is:

received signal2 received signal1

instead of 4 entries, have 2.

any ideas why?


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