strage cthread behavior

[Matej Kosik]

Hi

I started playing with hurd. I am trying
to gain some experience with `cthread'
library now.

I wrote following trivial program:

------------------------------------
#include <stdio.h>
#include <cthreads.h>

void child_fnc( int i )
{
        printf( "slave:0\n" );
}

int main()
{
        cthread_t child_thread;
        child_thread = cthread_fork( child_fnc, 30 );
        printf( "master:0\n" );
        cthread_join( child_thread );
        printf( "master:1\n" );
        return 0;
}
------------------------------------



if I run it as

        ./main

it gives me the output

        master:0
        slave:0
        master:1

e.g. one of the things which I expected

------------------------------------

if I run the same program as

        ./main > output

the contents of the `./output' file
will be (surprisingly)

        slave:0
        master:1

I expected the contents of `./output' file
to be the same as the output of the program
printed out on terminal.

Can somebody please explain it to me?
(or send a link to some document which
 explains it).

Matej Kosik

------------------------------------

NOTE (ATTACHMENT):
I attached `threads.tar.gz' file,
which holds programs concerning this problem

`threads/cthread/bug.1/main.c' contains
a program mentioned in this mail

`threads/cthread/bug.2' contains
a similar program with showing the similar
problem (it differs from `bug.1' program
in that it does not `join' the slave
but `detach' it)

`threads/pthread/bug.1' is an equivalent
program to `threads/cthread/bug.1', but
works on Linux and uses pthread instead
of cthread. I wrote it in order to see
whether it will have the bug mentioned
before --- it does not.

`threads/pthread/bug.2' is an equivalent
program to `threads/cthread/bug.2', but
works on Linux and uses pthread instead
of cthread. I wrote it in order to see
whether it will have the bug mentioned
before --- it does not.

thank you
-- 
http://altair.dcs.elf.stuba.sk/~kosik

threads.tar.gz
Description: GNU Zip compressed data