Ticket #18539: sendtest.c

#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <stdbool.h>

int main() {
    int fds[2];
    int domain;
    domain = AF_UNIX; // currently buggy: send hangs upon full buffer (no EBUFS, no silent drop)
 // domain = AF_INET; // SOCK_DGRAM: packets get dropped silently (send continues)
    printf("Domain: %i\n", domain);
    int ret = socketpair(domain, SOCK_DGRAM, 0, fds); // try also: SOCK_STREAM
    if(ret) {
        perror("Could not get socketpair");
        return 1;
    }

    struct timeval v = {
        .tv_sec = 1,
        .tv_usec = 0
    };

    // uncomment to allow send to timeout with ETIMEDOUT after 1 second
    //ret = setsockopt(fds[0], SOL_SOCKET, SO_SNDTIMEO, &v, sizeof(v));
    if(ret) {
        perror("setsockopt");
    }

    size_t bufLen = 1024;
    char *buf = calloc(bufLen, 1);
    int ok = 0;
    while(true) {
        printf("send %i\n", ok);
        ret = send(fds[0], &buf[0], bufLen, MSG_DONTWAIT);
        // eventually: EAGAIN (on Linux), ENOBUFS (on macOS), hang (on Haiku)
        if(ret < 0) {
            perror("send");
            break;
        } else {
            ok++;
        }
    }

    return 0;
}