dispatch-io-write-bug.c

#include <dispatch/dispatch.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>

int main()
{
    int pipes[2] = {0, 0};
    int err = pipe(pipes);
    if (err) {
        perror("pipe");
        return 1;
    }
    fprintf(stderr, "=== BEGIN ===\n");
    dispatch_queue_t q = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
    dispatch_io_t chan = dispatch_io_create(DISPATCH_IO_STREAM,
                                            pipes[1],
                                            q,
                                            ^(int error) {
                                                fprintf(stderr, "ERROR: %d\n", error);
                                            });
    dispatch_io_write(chan,
                      0,
                      dispatch_data_create("hallo\n", 6, q, NULL),
                      q,
                      ^(bool done, dispatch_data_t data, int error) {
                          if (!error) {
                              fprintf(stderr, "OK: %d, %p, %d\n", done, data, error);
                          } else {
                              fprintf(stderr, "ERROR: %d, %p, %d\n", done, data, error);
                          }
                      });
    char buf[7];
    read(pipes[0], buf, 6);
    buf[6] = 0;
    fprintf(stderr, "buf='%s'\n", buf);
    dispatch_sync(q, ^{ fprintf(stderr, "on it\n"); });
    dispatch_io_close(chan, DISPATCH_IO_STOP);
    atexit_b(^{
        fprintf(stderr, "===  END  ===\n");
    });
    return 0;
}