Comment author: administrator

Hello, this is a bug report of
Objective Caml version 3.01+4 (2001-06-18).
(Am I encouraged to post reports of +n versions ?)

Yes! Very much encouraged! It's better to catch bugs before the releases...

The following simple "folk-exec-cat" with thread does not work
correctly in this version of O'Caml. The program receives EOF
before cat finishes printing all the content.
I verified that with the official version of ocaml 3.01,
the program works correctly.

Interesting. The new thread-safe reimplementation of the Unix module
(provided by the bytecode threads library) is indeed buggy, because
the process forked by open_process_* has its standard descriptors
still in non-blocking mode, which causes problems with most programs.

Actually, this exposes another bug that has been here for a long time:
when a threaded program calls Unix.exec*, the standard descriptors are
left in non-blocking mode, with equally bad consequences.

I have fixed both issues by simply resetting the standard descriptors
to blocking mode in the exec* functions, which are also called by
open_process_*.

Thanks,

• Xavier

Comment author: administrator

Fixed 2001-07-04 by XL.