[libcamera-devel] [PATCH 3/4] libcamera: device_enumerator: Remove move() on search() return
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Tue Feb 12 23:39:52 CET 2019
Hi Jacopo,
Thank you for the patch.
On Tue, Feb 12, 2019 at 11:20:20PM +0100, Jacopo Mondi wrote:
> Remove the std::move() call on the shared_ptr<MediaDevice *> returned by
> the search() method and remove the std::move() call on temporary return
> value in pipeline handlers that use the method.
>
> Thanks to copy elision, the regular constructor of the newly created
> object is called, avoiding un-necessary copies.
>
> Furthermore, the use of std::move() in the return and assignment
> statements prevents the compiler from performing copy elision, forcing
> it to generate two sequences of un-necessary calls to the class'
> move constructor and destructor.
>
> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> src/libcamera/device_enumerator.cpp | 2 +-
> src/libcamera/pipeline/ipu3/ipu3.cpp | 4 ++--
> src/libcamera/pipeline/uvcvideo.cpp | 2 +-
> src/libcamera/pipeline/vimc.cpp | 2 +-
> test/v4l2_device/v4l2_device_test.cpp | 2 +-
> 5 files changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp
> index 03923b3bb457..7db40812906b 100644
> --- a/src/libcamera/device_enumerator.cpp
> +++ b/src/libcamera/device_enumerator.cpp
> @@ -308,7 +308,7 @@ std::shared_ptr<MediaDevice> DeviceEnumerator::search(const DeviceMatch &dm)
> LOG(DeviceEnumerator, Debug)
> << "Successful match for media device \""
> << media->driver() << "\"";
> - return std::move(media);
> + return media;
> }
> }
>
> diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
> index 34b03995ae31..f11e9cc61283 100644
> --- a/src/libcamera/pipeline/ipu3/ipu3.cpp
> +++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
> @@ -279,11 +279,11 @@ bool PipelineHandlerIPU3::match(DeviceEnumerator *enumerator)
> imgu_dm.add("ipu3-imgu 1 viewfinder");
> imgu_dm.add("ipu3-imgu 1 3a stat");
>
> - cio2_ = std::move(enumerator->search(cio2_dm));
> + cio2_ = enumerator->search(cio2_dm);
> if (!cio2_)
> return false;
>
> - imgu_ = std::move(enumerator->search(imgu_dm));
> + imgu_ = enumerator->search(imgu_dm);
> if (!imgu_)
> return false;
>
> diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
> index fc31c52c0ecd..bf0d2fee3851 100644
> --- a/src/libcamera/pipeline/uvcvideo.cpp
> +++ b/src/libcamera/pipeline/uvcvideo.cpp
> @@ -139,7 +139,7 @@ bool PipelineHandlerUVC::match(DeviceEnumerator *enumerator)
> {
> DeviceMatch dm("uvcvideo");
>
> - media_ = std::move(enumerator->search(dm));
> + media_ = enumerator->search(dm);
>
> if (!media_)
> return false;
> diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
> index 46840a4f4104..3aed24c3158a 100644
> --- a/src/libcamera/pipeline/vimc.cpp
> +++ b/src/libcamera/pipeline/vimc.cpp
> @@ -148,7 +148,7 @@ bool PipelineHandlerVimc::match(DeviceEnumerator *enumerator)
> dm.add("RGB/YUV Input");
> dm.add("Scaler");
>
> - media_ = std::move(enumerator->search(dm));
> + media_ = enumerator->search(dm);
> if (!media_)
> return false;
>
> diff --git a/test/v4l2_device/v4l2_device_test.cpp b/test/v4l2_device/v4l2_device_test.cpp
> index 18d014caf4c8..76f2e55d8cb4 100644
> --- a/test/v4l2_device/v4l2_device_test.cpp
> +++ b/test/v4l2_device/v4l2_device_test.cpp
> @@ -40,7 +40,7 @@ int V4L2DeviceTest::init()
> }
>
> DeviceMatch dm("uvcvideo");
> - media_ = std::move(enumerator_->search(dm));
> + media_ = enumerator_->search(dm);
> if (!media_)
> return TestSkip;
>
--
Regards,
Laurent Pinchart
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