From: "Lavrentiev, Anton (NIH/NLM/NCBI) [C]" <lavr@ncbi.nlm.nih.gov>
To: "'cygwin@cygwin.com'" <cygwin@cygwin.com>
Subject: Typo in <sys/select.h>?
Date: Tue, 5 Jul 2022 14:13:52 +0000 [thread overview]
Message-ID: <DM8PR09MB70954B30D740E778EB65BA41A5819@DM8PR09MB7095.namprd09.prod.outlook.com> (raw)
Hi,
There's some inconsistency between <sys/select.h> and <sys/param.h>:
sys/select.h has this:
-----------------------
/*
* Select uses bit masks of file descriptors in longs.
* These macros manipulate such bit fields (the filesystem macros use chars).
* FD_SETSIZE may be defined by the user, but the default here
* should be >= NOFILE (param.h).
*/
#ifndef FD_SETSIZE
#define FD_SETSIZE 64
#endif
----------------------
Now, this is the relevant part of sys/param.h looks like this:
----------------------
/* Max number of open files. The Posix version is OPEN_MAX. */
/* Number of fds is virtually unlimited in cygwin, but we must provide
some reasonable value for Posix conformance */
#define NOFILE 8192
----------------------
So it's either "<= NOFILE" that was actually meant to be there in the comment (or,
an equivalent "should NOT be > NOFILE"), or FD_SETSIZE should have been defined as 8192,
if the comment is actually correct. Or maybe I'm missing something here :-)
I understand that if I redefined FD_SETSIZE in my code before including <sys/select.h>,
it'd work with whatever large (or small) fd_set I need, but that's not what I'm after.
Anton Lavrentiev
Contractor NIH/NLM/NCBI
next reply other threads:[~2022-07-05 14:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-05 14:13 Lavrentiev, Anton (NIH/NLM/NCBI) [C] [this message]
2022-07-05 14:55 ` Andrey Repin
2022-07-05 21:51 ` Ken Brown
2022-07-06 7:42 ` Corinna Vinschen
2022-07-06 14:01 ` Jon Turney
2022-07-06 14:15 ` Corinna Vinschen
2022-07-06 14:22 ` Corinna Vinschen
2022-07-05 15:11 Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2022-07-06 13:19 Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2022-07-06 14:17 ` Corinna Vinschen
2022-07-06 14:17 Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2022-07-06 14:26 Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2022-07-06 15:07 ` Corinna Vinschen
2022-07-06 15:57 Lavrentiev, Anton (NIH/NLM/NCBI) [C]
2022-07-06 17:03 ` Ken Brown
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