Re: [PATCH] use unlocked io in getdelim

[Paolo Bonzini]

Eric Blake wrote:
> According to Paolo Bonzini on 8/27/2008 5:48 AM:
>> Under MacOS, getc is not a macro, only getc_unlocked is.  This patch
>> does two things: 1) it makes getdelim use getc_unlocked if it can wrap
>> the calls with flockfile/funlockfile; 2) it makes getdelim omit the
>> locking altogether if unlocked-io is in effect.  It speeds up sed by
>> almost 2x in very simple scripts with very little regular expression
>> matching (such as '/^something/!d').
> 
>> Ok?
> 
> Sounds interesting.  How does this compare with the current approach used
> by getndelim2, which uses freadptr to avoid getc?

I don't know. :-)  It could be even faster to use freadptr and memchr
indeed.  But getline is now completely off the profile for sed.

Paolo