FIFO doesn't block on read

Why the following program doesn't block on the second read call?

int pid = fork();

if(pid) {
    int fifo = open("testfifo", O_RDWR);

    char buf[20];

    while(1) {
        read(fifo, buf开发者_如何学运维, 10);
        puts(buf);
    }

} else {
    int fifo = open("testfifo", O_WRONLY);

    write(fifo, "teststring", 10);

    close(fifo);
}

return 0;

The second read call continues returning 0 even though the fifo become empty and it should block on the read call.

Am I missing something?

The OS is Windows and the pipe has been created with a mknod testfifo p.

I found, from another stackoverflow question, that i should open and close the "server" pipe, in this case the pipe of the parent process, each time; so here's the correct code:

int pid = fork();

if(pid) {
    char buf[20];

    while(1) {

        int fifo = open("testfifo", O_RDWR);
        read(fifo, buf, 15);
        close(fifo);

        puts(buf), fflush(stdout);
    }
} else {
    int fifo = open("testfifo", O_WRONLY);
    write(fifo, "teststring", 15);
    close(fifo);
}

You did not close the file

EDIT: deleted something embarrassing.