kevent.c

#include <sys/types.h>
#include <sys/event.h>
#include <sys/time.h>
#include <signal.h>
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <pthread.h>
#include <setjmp.h>

void evil_c_recover() {
    printf("%s\n", __PRETTY_FUNCTION__);
}

jmp_buf *evil_sig_jmp;
void evil_c_sig_handler(int sig) {
    printf("%s: %d (%s)\n", __PRETTY_FUNCTION__, sig, strsignal(sig));
    if (sig == SIGBUS || sig == SIGSEGV || sig == SIGFPE) {
        if (evil_sig_jmp)
            siglongjmp(*evil_sig_jmp, 1);
        abort();
    }
}
int q;

void* threadfunc(void* a) {
    while (1) {
        struct timespec timeout = { 5, 0 };
        struct kevent e;
        int status = kevent(q, NULL, 0, &e, 1, &timeout);

        if (status == 0) {
            printf("tick\n");
        } else if (status > 0) {
            printf("kevent: %d (%s): %d\n", (int) e.ident, strsignal((int) e.ident), (int) e.data);
            if (e.ident == SIGINT) {
                return NULL;
            }
        } else {
            fprintf(stderr, "cound not kevent.  Error is %d/%s\n", errno, strerror(errno));
            return NULL;
        }
    }
    return NULL;
}

int main(int argc, char **argv) {
    q = kqueue();
    pthread_t loop;
    assert(q != -1);

    struct kevent e;
    EV_SET(&e, SIGBUS, EVFILT_SIGNAL, EV_ADD | EV_ENABLE, 0, 0, NULL);
    assert(kevent(q, &e, 1, NULL, 0, NULL) != -1);
    EV_SET(&e, SIGSEGV, EVFILT_SIGNAL, EV_ADD | EV_ENABLE, 0, 0, NULL);
    assert(kevent(q, &e, 1, NULL, 0, NULL) != -1);
    EV_SET(&e, SIGFPE, EVFILT_SIGNAL, EV_ADD | EV_ENABLE, 0, 0, NULL);
    assert(kevent(q, &e, 1, NULL, 0, NULL) != -1);
    EV_SET(&e, SIGINT, EVFILT_SIGNAL, EV_ADD | EV_ENABLE, 0, 0, NULL);
    assert(kevent(q, &e, 1, NULL, 0, NULL) != -1);
    EV_SET(&e, SIGALRM, EVFILT_SIGNAL, EV_ADD | EV_ENABLE, 0, 0, NULL);
    assert(kevent(q, &e, 1, NULL, 0, NULL) != -1);

    signal(SIGBUS, evil_c_sig_handler);
    signal(SIGSEGV, evil_c_sig_handler);
    signal(SIGFPE, evil_c_sig_handler);
    signal(SIGINT, evil_c_sig_handler);
    signal(SIGALRM, evil_c_sig_handler);

    pthread_create(&loop, NULL, threadfunc, NULL);

    jmp_buf evil_c;
    evil_sig_jmp = &evil_c;
    if (sigsetjmp(evil_c, 1) == 0) {
        int a = 100;
        int b = 0;
        printf("%d/%d = %d\n", a, b, a/b);
    } else {
        printf("nope\n");
    }

    if (sigsetjmp(evil_c, 1) == 0) {
        int *a = 0;
        printf("%d\n", *a);
    } else {
        printf("nope\n");
    }
    alarm(1);

    pthread_join(loop, NULL);
    close(q);
    return 0;
}