Re: [PATCH 1/1] MSVC: port pthread code to native Windows threads

From: Johannes Sixt <j.sixt@viscovery.net>
To: "Andrzej K. Haczewski" <ahaczewski@gmail.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH 1/1] MSVC: port pthread code to native Windows threads
Date: Wed, 04 Nov 2009 09:24:47 +0100	[thread overview]
Message-ID: <4AF13A4F.5070300@viscovery.net> (raw)
In-Reply-To: <16cee31f0911032344m3263730l607c02eb4e9adef5@mail.gmail.com>

[please don't cull Cc list on this ML]

Andrzej K. Haczewski schrieb:
>> Pardon my ignorance, but is there a reason to not use Pthreads for Win32?
>>  http://sourceware.org/pthreads-win32/
>>
> 
> Not using pthreads on Windows makes Git:
> 1. faster on that platform

I believe this only if you present hard numbers. My guess is that (for
example) packing objects with two threads is still faster with a slow
pthreads emulation than without threading at all.

> 2. not depend on Pthreads for Win32

Why is this an advantage?

> IMHO that makes Git one step closer to become native on Windows, and
> is a sensible step.

Emulating pthreads on Windows with all its facets is an extremely
difficult task. If exact POSIX conformance is needed, I would choose an
existing package over doing it myself at any time.

Granted, we don't need the esoteric parts (cancelation points), which
would simplify the emulation a lot. But, as I pointed out in my other
mail, even a pthread_cond_wait() is not that trivial to implement with the
Windows API.

-- Hannes