[Ffmpeg-devel] [patch] fall back mmap() call for working on no-mmu systems

[Michael Niedermayer]

Hi

On Sat, Dec 16, 2006 at 01:59:53PM -0500, Mike Frysinger wrote:
> this patch tweaks libavformat/grab.c so that if the call to
> mmap(MAP_SHARED) fails, the code will retry the mmap() call but this
> time with MAP_PRIVATE ... this is needed to work on no-mmu linux
> systems where mmap(MAP_SHARED) typically is not supported
> -mike
> Index: libavformat/grab.c
> ===================================================================
> --- libavformat/grab.c	(revision 7322)
> +++ libavformat/grab.c	(working copy)
> @@ -57,6 +57,15 @@ static int aiw_init(VideoData *s);
>  static int aiw_read_picture(VideoData *s, uint8_t *data);
>  static int aiw_close(VideoData *s);
>  
> +static void *do_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
> +{
> +	void *ret;
> +	ret = mmap(start, length, prot, flags, fd, offset);
> +	if (ret == (unsigned char*)-1 && (flags & MAP_SHARED))
> +		ret = mmap(start, length, prot, (flags & ~MAP_SHARED) | MAP_PRIVATE, fd, offset);
> +	return ret;
> +}
> +

tabs are forbidden in svn and i see no sense in having this once used thing
implemented as its own function

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Why not whip the teacher when the pupil misbehaves? -- Diogenes of Sinope