close(), exceptions and problems

[Erwin S. Andreasen]

On 24 Mar 2001 16:22:43 GMT, Marcin 'Qrczak' Kowalczyk wrote:
>Sat, 24 Mar 2001 12:23:03 +0000 (UTC), Erwin S. Andreasen <erwin at andreasen.com> pisze:
>
>> 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");
>
>Linux documentation says otherwise.

That's GNU libc documentation actually.

>    `EINTR'
>          The `close' call was interrupted by a signal.  *Note
>          Interrupted Primitives::.  Here is an example of how to
>          handle `EINTR' properly:
>
>               TEMP_FAILURE_RETRY (close (desc));

But this only happens when SA_RESTART is not set (OK, I thought it was
SA_NORESTART to *disable* restarting but it's SA_RESTART to enable
restarting).

Read the "Interrupted Primitives" node for more information.

Maybe the threading library on the platform the original poster uses does not
set the SA_RESTART flag (if its threads are userspace, switched by receiving
SIUGUSR1) ? But that's hard to believe.


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<erwin at andreasen.com>           Herlev, Denmark       Software Designer
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