[libcamera-devel] [PATCH v3 2/4] libcamera: ipa: raspberrypi: ALSC: Improve locking in a few places

[Naushir Patuck]

Hi David,

Thank you for the patch.

On Sat, 1 Aug 2020 at 09:02, David Plowman
<david.plowman at raspberrypi.com> wrote:
>
> Fix up a few locations where we call notify_one() with the lock
> held. In particular, restartAsync does not need to be called with the
> lock held for its entire duration.
>
> Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

Reviewed-by: Naushir Patuck <naush at raspberrypi.com>


> ---
>  src/ipa/raspberrypi/controller/rpi/alsc.cpp | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/src/ipa/raspberrypi/controller/rpi/alsc.cpp b/src/ipa/raspberrypi/controller/rpi/alsc.cpp
> index 76e2f04..12359dc 100644
> --- a/src/ipa/raspberrypi/controller/rpi/alsc.cpp
> +++ b/src/ipa/raspberrypi/controller/rpi/alsc.cpp
> @@ -32,8 +32,8 @@ Alsc::~Alsc()
>         {
>                 std::lock_guard<std::mutex> lock(mutex_);
>                 async_abort_ = true;
> -               async_signal_.notify_one();
>         }
> +       async_signal_.notify_one();
>         async_thread_.join();
>  }
>
> @@ -268,8 +268,11 @@ void Alsc::restartAsync(StatisticsPtr &stats, Metadata *image_metadata)
>         frame_phase_ = 0;
>         // copy the camera mode so it won't change during the calculations
>         async_camera_mode_ = camera_mode_;
> -       async_start_ = true;
>         async_started_ = true;
> +       {
> +               std::lock_guard<std::mutex> lock(mutex_);
> +               async_start_ = true;
> +       }
>         async_signal_.notify_one();
>  }
>
> @@ -315,7 +318,6 @@ void Alsc::Process(StatisticsPtr &stats, Metadata *image_metadata)
>         RPI_LOG("Alsc: frame_phase " << frame_phase_);
>         if (frame_phase_ >= (int)config_.frame_period ||
>             frame_count2_ < (int)config_.startup_frames) {
> -               std::unique_lock<std::mutex> lock(mutex_);
>                 if (async_started_ == false) {
>                         RPI_LOG("ALSC thread starting");
>                         restartAsync(stats, image_metadata);
> @@ -339,8 +341,8 @@ void Alsc::asyncFunc()
>                 {
>                         std::lock_guard<std::mutex> lock(mutex_);
>                         async_finished_ = true;
> -                       sync_signal_.notify_one();
>                 }
> +               sync_signal_.notify_one();
>         }
>  }
>
> --
> 2.20.1
>
> _______________________________________________
> libcamera-devel mailing list
> libcamera-devel at lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel