Re: [PATCH] Make NO_PTHREADS the sole thread configuration variable

From: Junio C Hamano <gitster@pobox.com>
Date: Jan 30, 2010, 17:43 UTC
Message-ID: <7vwryzqyjb.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1264814539-27209-1-git-send-email-dpmcgee@gmail.com>

Dan McGee <dpmcgee@gmail.com> writes:

Show 5 quoted lines

> When the first piece of threaded code was introduced in commit 8ecce684, it
> came with its own THREADED_DELTA_SEARCH Makefile option. Since this time,
> more threaded code has come into the codebase and a NO_PTHREADS option has
> also been added. Get rid of the original option as the newer, more generic
> option covers everything we need.

The patch is a good change but only in the "if it were like this from day one, things would have been much simpler" sense. It is a breakage to existing users with customized THREADED_DELTA_SEARCH in their config.mak files, isn't it?

If we take only the part of your patch that applies to Makefile, but exclude the first hunk (description of THREADED_DELTA_SEARCH) and the last hunk (the necessary part to keep THREADED_DELTA_SEARCH working), and instead add something like:

	ifndef NO_PTHREADS
        	THREADED_DELTA_SEARCH = YesPlease
	endif

immediately before we include config.mak, would that be a workable solution to:

 (1) keep existing users happy;

 (2) remove the redundant logic to compute the default for two Make
     variables; and

 (3) keep control over use of threading in general _and_ use of
     threading in delta computation?