close(), exceptions and problems

[Erwin S. Andreasen]

On 23 Mar 2001 09:30:46 GMT, Antti Kuntsi wrote:

>I have run into the following problem with python and close()s. When the
>system is under a heavy load the close() system call can be interrupted,
>but the Python never detects this. This leads into a lot of problems,
>including at least the following:

What exactly do you mean by "interrupted" ?

close(), the system call, usually cannot fail (unless you try to close a fd
that is not open).

If a system call is interrupted by a signal, it is restarted automatically
(unless the signal handler was setup with SA_NORESTART *or* the system call in
question is select(), which is never automatically restarted).

But if you call close(fd) you aren't supposed to do something like:

int fd, rv;
while (((rv = close(fd)) < 0 && errno == EINTR))
	;
if (rv < 0)
	perror("close");


the system call will be automatically restarted for you.


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<erwin at andreasen.com>           Herlev, Denmark       Software Designer
<URL:http://www.andreasen.org/>       <*>         LASAT^WEicon Networks
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