Re: [PATCH 1/2] Make xmalloc and xrealloc thread-safe

From: "Shawn O. Pearce" <spearce@spearce.org>
To: Fredrik Kuivinen <frekui@gmail.com>
Cc: git@vger.kernel.org, Johannes Sixt <j6t@kdbg.org>,
	Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH 1/2] Make xmalloc and xrealloc thread-safe
Date: Tue, 23 Mar 2010 11:43:09 -0700	[thread overview]
Message-ID: <20100323184309.GA31668@spearce.org> (raw)
In-Reply-To: <20100323173114.GB4218@fredrik-laptop>

Fredrik Kuivinen <frekui@gmail.com> wrote:
> +static int multiple_threads;
> +#ifndef NO_PTHREADS
> +int xpthread_create(pthread_t *thread, const pthread_attr_t *attr,
> +		    void *(*start_routine)(void*), void *arg)
> +{
> +	multiple_threads = 1;
> +	return pthread_create(thread, attr, start_routine, arg);
> +}
> +#endif
> +
>  void *xmalloc(size_t size)
>  {
>  	void *ret = malloc(size);
>  	if (!ret && !size)
>  		ret = malloc(1);
> -	if (!ret) {
> +	if (!ret && !multiple_threads) {
>  		release_pack_memory(size, -1);

So by "make thread safe" you really mean "disable release of
least-frequently used pack windows once any thread starts".

If that is what we are doing, disabling the release of pack windows
when malloc fails, why can't we do that all of the time?

-- 
Shawn.