Re: [PATCH] MSVC: Windows-native implementation for subset of Pthreads API

From: Nicolas Pitre <nico@fluxnic.net>
Date: Nov 5, 2009, 00:22 UTC
Message-ID: <alpine.LFD.2.00.0911041915120.10340@xanadu.home>
In-Reply-To: <4AF214D5.6050202@gmail.com>

On Thu, 5 Nov 2009, Andrzej K. Haczewski wrote:

Show 5 quoted lines

> @@ -1638,6 +1657,8 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size,
>  				delta_search_threads);
>  	p = xcalloc(delta_search_threads, sizeof(*p));
>  
> +	init_threaded_search();

Careful.  At the beginning of the function you'll find:

        if (delta_search_threads <= 1) {
                find_deltas(list, &list_size, window, depth, processed);
                return;
        }

That is, if we have thread support compiled in but we're told to use only one thread, then the bulk of the work splitting is bypassed entirely. Inside find_deltas() there will still be pthread_mutex_lock() and pthread_mutex_unlock() calls even if no threads are spawned.

Nicolas