89 lines
1.7 KiB
C
89 lines
1.7 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 <time.h>
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#include <errno.h>
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#include <stdlib.h>
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void catcher(int sig, siginfo_t *info, void *p) {
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printf("Signal catcher called for signal %d from %d\n", sig, info->si_pid);
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exit(1);
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}
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void timestamp(char *str) {
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time_t t;
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time(&t);
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printf("The time %s is %s", str, ctime(&t));
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}
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void echoSIGUSR1(void){
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int result;
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struct sigaction sigact;
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sigset_t waitset;
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siginfo_t info;
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union sigval v;
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printf("CHILD pid %d\n", getpid());
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v.sival_int = 0;
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sigemptyset(&sigact.sa_mask);
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sigact.sa_flags = SA_SIGINFO;
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sigact.sa_sigaction = catcher;
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sigaction(SIGUSR1, &sigact, NULL);
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sigemptyset(&waitset);
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sigaddset(&waitset, SIGUSR1);
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sigprocmask(SIG_BLOCK, &waitset, NULL);
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while(v.sival_int < 5){
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result = sigwaitinfo(&waitset, &info);
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v.sival_int = 1 + info.si_value.sival_int;
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printf("CHILD sigqueue %d to %d\n", v.sival_int, info.si_pid);
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sigqueue(info.si_pid, result, v);
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}
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}
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int main(int argc, char *argv[]) {
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int result;
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struct sigaction sigact;
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sigset_t waitset;
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siginfo_t info;
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union sigval v;
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pid_t child;
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switch(child = fork()){
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case 0:
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echoSIGUSR1();
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exit(0);
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break;
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case -1:
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exit(1);
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break;
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default:
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break;
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}
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printf("PARENT pid %d sleep(3)\n", getpid());
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sleep(3);
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v.sival_int = 0;
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sigemptyset(&sigact.sa_mask);
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sigact.sa_flags = SA_SIGINFO;
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sigact.sa_sigaction = catcher;
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sigaction(SIGUSR1, &sigact, NULL);
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sigemptyset(&waitset);
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sigaddset(&waitset, SIGUSR1);
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sigprocmask(SIG_BLOCK, &waitset, NULL);
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result = SIGUSR1;
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do{
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printf("PARENT sigqueue %d\n", v.sival_int);
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sigqueue(child, result, v);
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result = sigwaitinfo(&waitset, &info);
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v.sival_int = 1 + info.si_value.sival_int;
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} while(v.sival_int < 5);
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exit(0);
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}
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