Revelations on Java signal handling and termination

#include stdio.h
#include stdlib.h
#include signal.h

struct sigaction oldHandler;

/* A well behaved signal handler */
void mySignalHandler(int sig,  siginfo_t *siginfo, void *context) {

    /* Do processing for passed signal */
    
    ...

    /* Chain back to old signal handler, to give it a chance to process the signal */
    /* Normally this should only be done if the signal was not dealt with by this  */
    /* signal handler                                                              */
    if ( oldHandler.sa_flags  SA_SIGINFO ) {
        if ( (oldHandler.sa_sigaction != SIG_DFL) 
             (oldHandler.sa_sigaction != (void (*)(int, siginfo_t *, void *))SIG_IGN) ) {
            oldHandler.sa_sigaction(sig, siginfo, context);
        }
    } else {
        if ( (oldHandler.sa_handler != SIG_DFL) 
             (oldHandler.sa_handler != SIG_IGN) ) {
            oldHandler.sa_handler(sig);
        }
    }
}

int main(int argc, char *argv[]) {

    /* Install mySignalHandler for SIGSEGV */
    struct sigaction sigAct;
    int              status;

    sigAct.sa_handler   = 0;               /* set to 0 since we are using sa_sigaction */
    sigAct.sa_sigaction = mySignalHandler; /* Our signal handler */
    sigfillset(&sigAct.sa_mask);           /* Disable all signals for our handler */
    sigAct.sa_flags = SA_SIGINFO;          /* sa_sigaction specifies the handler */

    status = sigaction(SIGSEGV, &sigAct, &oldHandler);
    if (status != 0) {
        perror("Failed to install handler for signal SIGSEGV");
        exit(1);
    }

    /* This will invoke the signal handler */
    {   int *p = (int *)123;
        *p = 1;
    }
    return 0;
}    

#include stdio.h
#include stdlib.h
#include signal.h

void (*oldHandler)(int);

/* A well behaved Signal handler */
void mySignalHandler(int sig) {

    /* Do processing for passed signal */

    ...

    /* Chain back to old signal handler, to give it a chance to process */
    /* the signal. Normally this should only be done if the signal          */
    /* was not dealt with by this signal handler                                   */
    if ( oldHandler != SIG_DFL oldHandler != SIG_IGN) {
        oldHandler(sig);
    }
}

int main(int argc, char *argv[]) {

    /* Install mySignalHandler for signal SIGSEGV */
    oldHandler = signal(SIGSEGV, mySignalHandler);
    if (oldHandler == SIG_ERR) {
        perror("Failed to install handler for SIGSEGV");
        exit(1);
    }
    
    /* This will invoke the signal handler */
    {   int *p = (int *)123;
        *p = 1;
    }
    return 0;
}