From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin-patches@cygwin.com
Subject: Re: [PATCH] Cygwin: getdtablesize: always return OPEN_MAX_MAX
Date: Thu, 28 Jan 2021 11:20:29 +0100 [thread overview]
Message-ID: <20210128102029.GY4393@calimero.vinschen.de> (raw)
In-Reply-To: <20210128025150.46708-1-kbrown@cornell.edu>
On Jan 27 21:51, Ken Brown via Cygwin-patches wrote:
> According to the Linux man page for getdtablesize(3), the latter is
> supposed to return "the maximum number of files a process can have
> open, one more than the largest possible value for a file descriptor."
> The constant OPEN_MAX_MAX is the only limit enforced by Cygwin, so we
> now return that.
>
> Previously getdtablesize returned the current size of cygheap->fdtab,
> Cygwin's internal file descriptor table. But this is a dynamically
> growing table, and its current size does not reflect an actual limit
> on the number of open files.
>
> With this change, gnulib now reports that getdtablesize and
> fcntl(F_DUPFD) work on Cygwin. Packages like GNU tar that use the
> corresponding gnulib modules will no longer use gnulib replacements on
> Cygwin.
> ---
> winsup/cygwin/syscalls.cc | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
> index 5da05b18a..1f16d54b9 100644
> --- a/winsup/cygwin/syscalls.cc
> +++ b/winsup/cygwin/syscalls.cc
> @@ -2887,7 +2887,7 @@ setdtablesize (int size)
> extern "C" int
> getdtablesize ()
> {
> - return cygheap->fdtab.size;
> + return OPEN_MAX_MAX;
> }
getdtablesize is used internally, too. After this change, the values
returned by sysconf and getrlimit should be revisited as well.
Thanks,
Corinna
next prev parent reply other threads:[~2021-01-28 10:20 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-28 2:51 Ken Brown
2021-01-28 10:20 ` Corinna Vinschen [this message]
2021-01-28 13:42 ` Ken Brown
2021-01-28 16:07 ` Corinna Vinschen
2021-01-28 16:13 ` Corinna Vinschen
2021-01-28 22:28 ` Ken Brown
2021-01-29 19:23 ` Ken Brown
2021-02-01 9:42 ` Corinna Vinschen
2021-01-28 20:33 ` Ken Brown
2021-02-01 9:50 ` Corinna Vinschen
2021-02-01 10:46 ` Corinna Vinschen
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