c++ pipe buffering disable - c++

Question

How to disable buffering in pipe. I'm creating a simple recorder/player for I/O. To do this I need record output witch time delays.
To record delays, I need something like this
example tekst
"wait 1s"
example tekst
"wait 1s"
example tekst
...
but if I use
pipe2(in, O_DIRECT );
i see something like this
"wait 100s"
"100 times" example tekst
"wait 100s"
"100 times" example tekst
...
man7 tells:
O_DIRECT (since Linux 3.4)
Create a pipe that performs I/O in "packet" mode. Each
write(2) to the pipe is dealt with as a separate packet, and
read(2)s from the pipe will read one packet at a time.
I tried to disable buffering, by:
fcntl(in[1], F_SETPIPE_SZ, 1);
but it's still not working.
read.cpp
#define _GNU_SOURCE
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ioctl.h>
#include <poll.h>
#include <assert.h>
bool keep = true;
void intHandler(int dummy) {
keep = 0;
}
int main(void) {
signal(SIGINT, intHandler);
int in[2];
int out[2];
int pid;
int fo;
char buf[1024];
pipe2(in, O_DIRECT );
pipe2(out, O_DIRECT );
pid = fork();
if (pid == -1) {
perror("fork");
exit(1);
}
if (pid == 0) {
close(in[0]);
close(out[1]);
close(0);
close(1);
dup2(in[1], 1);
dup2(out[0], 0);
close(in[1]);
close(out[0]);
sleep(1);
char *newargv[] = {"/root/Pulpit/a1", NULL, NULL, NULL};
char *newenviron[] = {NULL};
int ret = execve("/root/Pulpit/a1", newargv, newenviron);
printf("%d", ret);
return 0;
} else {
close(out[0]);
close(in[1]);
int n = 0;
while (keep) {
int wyn = read(in[0], buf, 1024);
if (wyn > 0) {
char aa[1024];
write(1, buf, wyn);
fsync(1);
}
}
}
return (0);
}
a1.cpp
#include <cstdlib>
#include <unistd.h>
#include "stdio.h"
using namespace std;
/*
*
*/
int main(int argc, char** argv) {
while(true){
printf("example text\n");
usleep(100000);
}
return 0;
}