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Subject:	RE: Proposal: check and read /etc/{passwd,group} less frequently.
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Date:	Fri, 14 Sep 2001 16:40:43 +1000
Message-ID:	<EA18B9FA0FE4194AA2B4CDB91F73C0EF08F177@itdomain002.itdomain.net.au>
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Thread-Topic:	Proposal: check and read /etc/{passwd,group} less frequently.
Thread-Index:	AcE8551GXV53lN5jQx+ZgPsum87Q1gAAAr4g
From:	"Robert Collins" <robert DOT collins AT itdomain DOT com DOT au>
To:	<cygwin-developers AT cygwin DOT com>
X-MIME-Autoconverted:	from quoted-printable to 8bit by delorie.com id CAA26072

> -----Original Message-----
> From: Kazuhiro Fujieda [mailto:fujieda AT jaist DOT ac DOT jp]
> Sent: Friday, September 14, 2001 4:49 PM
> To: cygwin-developers AT cygwin DOT com
> Subject: Proposal: check and read /etc/{passwd,group} less frequently.
> 
> 
> I feel that there is no need to check and read
> /etc/{passwd,group} on every getpw* and getgw* functions.
>
> Is it enough frequent that the check is held only in 
> internal_getlogin?

How often is internal_getlogin called relative to get(p|g)w*?

> If so, read_etc_{passwd,group} don't need to support multi threads
> and can be more simple.

I don't see how they would no longer need thread protection.
internal_getlogin could be updating the cache while a user thread calls
getpwuid. As far as the user is concerned, they may have a mutex or some
other mechanism no to step on their own data, instead of using
getpwuid_r, but we cannot afford to step on our internal data
regardless.

Ro

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