[libcamera-devel] [RFC 01/11] libcamera: Always check return value of MediaDevice::acquire()

[Laurent Pinchart]

Hi Niklas,

Thank you for the patch.

On Sun, Apr 14, 2019 at 03:34:56AM +0200, Niklas Söderlund wrote:
> In preparation of adding more responsibility to MediaDevice::acquire()
> make sure all callers checks and acts properly to its return value.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> ---
>  src/libcamera/pipeline/ipu3/ipu3.cpp         | 10 ++++------
>  src/libcamera/pipeline/uvcvideo.cpp          |  3 ++-
>  src/libcamera/pipeline/vimc.cpp              |  3 ++-
>  test/media_device/media_device_link_test.cpp |  6 +++++-
>  test/v4l2_device/v4l2_device_test.cpp        |  3 ++-
>  test/v4l2_subdevice/v4l2_subdevice_test.cpp  |  6 +++++-
>  6 files changed, 20 insertions(+), 11 deletions(-)
> 
> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> index ca09da753b908448..d8de6b3c36314fc0 100644
> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> @@ -451,21 +451,19 @@ bool PipelineHandlerIPU3::match(DeviceEnumerator *enumerator)
>  	imgu_dm.add("ipu3-imgu 1 viewfinder");
>  	imgu_dm.add("ipu3-imgu 1 3a stat");
>  
> -	/*
> -	 * It is safe to acquire both media devices at this point as
> -	 * DeviceEnumerator::search() skips the busy ones for us.
> -	 */
>  	cio2MediaDev_ = enumerator->search(cio2_dm);
>  	if (!cio2MediaDev_)
>  		return false;
>  
> -	cio2MediaDev_->acquire();
> +	if (!cio2MediaDev_->acquire())
> +		return false;
>  
>  	imguMediaDev_ = enumerator->search(imgu_dm);
>  	if (!imguMediaDev_)
>  		return false;
>  
> -	imguMediaDev_->acquire();
> +	if (!imguMediaDev_->acquire())
> +		return false;
>  
>  	/*
>  	 * Disable all links that are enabled by default on CIO2, as camera
> diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
> index cd472cfadd86b7ba..5214bfd3097b8217 100644
> --- a/src/libcamera/pipeline/uvcvideo.cpp
> +++ b/src/libcamera/pipeline/uvcvideo.cpp
> @@ -184,7 +184,8 @@ bool PipelineHandlerUVC::match(DeviceEnumerator *enumerator)
>  	if (!media_)
>  		return false;
>  
> -	media_->acquire();
> +	if (!media_->acquire())
> +		return false;
>  
>  	std::unique_ptr<UVCCameraData> data = utils::make_unique<UVCCameraData>(this);
>  
> diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
> index c8bbe2a19847ba1e..e5e78ccedd59ae66 100644
> --- a/src/libcamera/pipeline/vimc.cpp
> +++ b/src/libcamera/pipeline/vimc.cpp
> @@ -194,7 +194,8 @@ bool PipelineHandlerVimc::match(DeviceEnumerator *enumerator)
>  	if (!media_)
>  		return false;
>  
> -	media_->acquire();
> +	if (!media_->acquire())
> +		return false;
>  
>  	std::unique_ptr<VimcCameraData> data = utils::make_unique<VimcCameraData>(this);
>  
> diff --git a/test/media_device/media_device_link_test.cpp b/test/media_device/media_device_link_test.cpp
> index 58a55cdfee634c0b..4b8de3bee722e912 100644
> --- a/test/media_device/media_device_link_test.cpp
> +++ b/test/media_device/media_device_link_test.cpp
> @@ -51,7 +51,11 @@ class MediaDeviceLinkTest : public Test
>  			return TestSkip;
>  		}
>  
> -		dev_->acquire();
> +		if (!dev_->acquire()) {
> +			cerr << "Unable to acquire media device: "

I'd drop the colon ':'.

> +			     << dev_->deviceNode() << endl;
> +			return TestSkip;
> +		}
>  
>  		if (dev_->open()) {
>  			cerr << "Failed to open media device at "
> diff --git a/test/v4l2_device/v4l2_device_test.cpp b/test/v4l2_device/v4l2_device_test.cpp
> index 4225291bbb6e23f0..90e5f7a3ee0c0f2f 100644
> --- a/test/v4l2_device/v4l2_device_test.cpp
> +++ b/test/v4l2_device/v4l2_device_test.cpp
> @@ -46,7 +46,8 @@ int V4L2DeviceTest::init()
>  	if (!media_)
>  		return TestSkip;
>  
> -	media_->acquire();
> +	if (!media_->acquire())
> +		return TestSkip;
>  
>  	MediaEntity *entity = media_->getEntityByName("vivid-000-vid-cap");
>  	if (!entity)
> diff --git a/test/v4l2_subdevice/v4l2_subdevice_test.cpp b/test/v4l2_subdevice/v4l2_subdevice_test.cpp
> index 06582969eb45f658..21335efbad4d5668 100644
> --- a/test/v4l2_subdevice/v4l2_subdevice_test.cpp
> +++ b/test/v4l2_subdevice/v4l2_subdevice_test.cpp
> @@ -45,7 +45,11 @@ int V4L2SubdeviceTest::init()
>  		return TestSkip;
>  	}
>  
> -	media_->acquire();
> +	if (!media_->acquire()) {
> +		cerr << "Unable to acquire media device: "

Same here.

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> +		     << media_->deviceNode() << endl;
> +		return TestSkip;
> +	}
>  
>  	int ret = media_->open();
>  	if (ret) {

-- 
Regards,

Laurent Pinchart