Comment 8 for bug 1058200

Revision history for this message
Tanu Kaskinen (tanuk) wrote : Re: [pulseaudio-discuss] [PATCH] stream: Return error in case a client peeks to early

On Mon, 2012-10-01 at 17:06 +0200, David Henningsson wrote:
> If there is no silence memblock and no data, pa_memblockq_peek can
> return NULL. In this case, do not crash on an assertion in
> pa_memblock_acquire, but instead return a proper error to the client.

If there is no data in the buffer, pa_stream_peek() is supposed to
return NULL according to the documentation. And it does that: if there's
no data, pa_memblock_peek() will return a negative value, causing
pa_stream_peek() to return NULL.

The problem is the case where the buffer does contain data, but not at
the read index. That is, there is a hole in the buffer. The client
documentation doesn't have any warnings about holes, so the only safe
way to handle holes is to return silence. Fixing this should be a simple
matter of giving a silence memchunk when creating record_memblockq.

--
Tanu