[libcamera-devel] [PATCH] qcam: Clear the pool of free requests upon stopCapture()

[Kieran Bingham]

Hi Paul,

On 12/11/2020 05:02, Paul Elder wrote:
> To enable reusing Request objects, we kept a pool of free Requests. This
> pool was not cleared upon stopping capture, however, which caused a
> segfault when switching to another camera. Fix this by clearing the
> Request pool on stopCapture().
> 
> Fixes: c753223ad6b9 ("libcamera, android, cam, gstreamer, qcam, v4l2:
> Reuse Request")
> Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>


Fixes things for me!

When this crashed for me, it was hitting code in the Request class, is
there anything we need to do to be more defensive about this?

Was that just because we were using a Request object which had been
free'd or something?

Anyway, for this fix :

Tested-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>



> ---
>  src/qcam/main_window.cpp | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
> index f140313e..2502ecd4 100644
> --- a/src/qcam/main_window.cpp
> +++ b/src/qcam/main_window.cpp
> @@ -579,6 +579,7 @@ void MainWindow::stopCapture()
>  	mappedBuffers_.clear();
>  
>  	requests_.clear();
> +	freeQueue_.clear();
>  
>  	delete allocator_;
>  
> 

-- 
Regards
--
Kieran