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Subject: Re: Typo in <sys/select.h>?
Thread-Topic: Typo in <sys/select.h>?
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Date: Wed, 6 Jul 2022 14:26:26 +0000
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From: "Lavrentiev, Anton \(NIH/NLM/NCBI\) \[C\] via Cygwin" <cygwin AT cygwin DOT com>
Reply-To: "Lavrentiev, Anton \(NIH/NLM/NCBI\) \[C\]" <lavr AT ncbi DOT nlm DOT nih DOT gov>
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Sender: "Cygwin" <cygwin-bounces+archive-cygwin=delorie DOT com AT cygwin DOT com>

> DESCRIPTION
>        WARNING: select() can monitor only file descriptors  numbers  that  are
>        less  than  FD_SETSIZE (1024)-an unreasonably low limit for many modern

Whoever wrote this, was wrong (they might have never consulted the actual kernel code, or were just
blindsided by FD_SETSIZE being a predefined constant).  You can take a look at the kernel source code,
if you don't believe me.

This select() trick has been like that from the earliest days of Linux, and the behavior is carefully carried over.

https://github.com/torvalds/linux/blob/master/fs/select.c#L625

It's just an FYI :-)

Anton Lavrentiev
Contractor NIH/NLM/NCBI


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