[libcamera-devel] [PATCH 2/2] libcamera: device_enumerator: Convey device ownership through unique_ptr
Kieran Bingham
kieran.bingham at ideasonboard.com
Mon Mar 23 15:08:52 CET 2020
Hi Laurent,
On 21/03/2020 18:09, Laurent Pinchart wrote:
> Replace usage of shared_ptr with unique_ptr to convey media device
> ownership internally in the enumerators when creating the media device.
> Once a media device has all its dependencies met, it is converted to a
> shared_ptr to keep the external API unchanged.
Looks ok, my only worry is that it could become easy to 'forget' to move
when needed? Or will unique_ptr fail/be loud when we need to move and
don't ?
Anyway,
Reviewed-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> src/libcamera/device_enumerator.cpp | 10 +++++-----
> src/libcamera/device_enumerator_sysfs.cpp | 8 ++++----
> src/libcamera/device_enumerator_udev.cpp | 8 ++++----
> src/libcamera/include/device_enumerator.h | 4 ++--
> src/libcamera/include/device_enumerator_sysfs.h | 2 +-
> src/libcamera/include/device_enumerator_udev.h | 8 ++++----
> 6 files changed, 20 insertions(+), 20 deletions(-)
>
> diff --git a/src/libcamera/device_enumerator.cpp b/src/libcamera/device_enumerator.cpp
> index 89ed67ebb115..dd17e3e32e6c 100644
> --- a/src/libcamera/device_enumerator.cpp
> +++ b/src/libcamera/device_enumerator.cpp
> @@ -208,9 +208,9 @@ DeviceEnumerator::~DeviceEnumerator()
> *
> * \return Created media device instance on success, or nullptr otherwise
> */
> -std::shared_ptr<MediaDevice> DeviceEnumerator::createDevice(const std::string &deviceNode)
> +std::unique_ptr<MediaDevice> DeviceEnumerator::createDevice(const std::string &deviceNode)
> {
> - std::shared_ptr<MediaDevice> media = std::make_shared<MediaDevice>(deviceNode);
> + std::unique_ptr<MediaDevice> media = std::make_unique<MediaDevice>(deviceNode);
>
> int ret = media->populate();
> if (ret < 0) {
> @@ -236,12 +236,12 @@ std::shared_ptr<MediaDevice> DeviceEnumerator::createDevice(const std::string &d
> * This method shall be called after all members of the entities of the
> * media graph have been confirmed to be initialized.
> */
> -void DeviceEnumerator::addDevice(const std::shared_ptr<MediaDevice> &media)
> +void DeviceEnumerator::addDevice(std::unique_ptr<MediaDevice> &&media)
> {
> LOG(DeviceEnumerator, Debug)
> << "Added device " << media->deviceNode() << ": " << media->driver();
>
> - devices_.push_back(media);
> + devices_.push_back(std::move(media));
> }
>
> /**
> @@ -290,7 +290,7 @@ void DeviceEnumerator::removeDevice(const std::string &deviceNode)
> */
> std::shared_ptr<MediaDevice> DeviceEnumerator::search(const DeviceMatch &dm)
> {
> - for (std::shared_ptr<MediaDevice> media : devices_) {
> + for (std::shared_ptr<MediaDevice> &media : devices_) {
> if (media->busy())
> continue;
>
> diff --git a/src/libcamera/device_enumerator_sysfs.cpp b/src/libcamera/device_enumerator_sysfs.cpp
> index 197ca235879b..3446db59e9d4 100644
> --- a/src/libcamera/device_enumerator_sysfs.cpp
> +++ b/src/libcamera/device_enumerator_sysfs.cpp
> @@ -72,11 +72,11 @@ int DeviceEnumeratorSysfs::enumerate()
> continue;
> }
>
> - std::shared_ptr<MediaDevice> media = createDevice(devnode);
> + std::unique_ptr<MediaDevice> media = createDevice(devnode);
> if (!media)
> continue;
>
> - if (populateMediaDevice(media) < 0) {
> + if (populateMediaDevice(media.get()) < 0) {
> LOG(DeviceEnumerator, Warning)
> << "Failed to populate media device "
> << media->deviceNode()
> @@ -84,7 +84,7 @@ int DeviceEnumeratorSysfs::enumerate()
> continue;
> }
>
> - addDevice(media);
> + addDevice(std::move(media));
> }
>
> closedir(dir);
> @@ -92,7 +92,7 @@ int DeviceEnumeratorSysfs::enumerate()
> return 0;
> }
>
> -int DeviceEnumeratorSysfs::populateMediaDevice(const std::shared_ptr<MediaDevice> &media)
> +int DeviceEnumeratorSysfs::populateMediaDevice(MediaDevice *media)
> {
> /* Associate entities to device node paths. */
> for (MediaEntity *entity : media->entities()) {
> diff --git a/src/libcamera/device_enumerator_udev.cpp b/src/libcamera/device_enumerator_udev.cpp
> index ea3f6b7c9ae0..9cbc7e47d2d9 100644
> --- a/src/libcamera/device_enumerator_udev.cpp
> +++ b/src/libcamera/device_enumerator_udev.cpp
> @@ -76,7 +76,7 @@ int DeviceEnumeratorUdev::addUdevDevice(struct udev_device *dev)
> return -ENODEV;
>
> if (!strcmp(subsystem, "media")) {
> - std::shared_ptr<MediaDevice> media =
> + std::unique_ptr<MediaDevice> media =
> createDevice(udev_device_get_devnode(dev));
> if (!media)
> return -ENODEV;
> @@ -96,7 +96,7 @@ int DeviceEnumeratorUdev::addUdevDevice(struct udev_device *dev)
> << "Defer media device " << media->deviceNode()
> << " due to " << ret << " missing dependencies";
>
> - pending_.emplace_back(media, deps);
> + pending_.emplace_back(std::move(media), std::move(deps));
> MediaDeviceDeps *mediaDeps = &pending_.back();
> for (const auto &dep : mediaDeps->deps_)
> devMap_[dep.first] = mediaDeps;
> @@ -104,7 +104,7 @@ int DeviceEnumeratorUdev::addUdevDevice(struct udev_device *dev)
> return 0;
> }
>
> - addDevice(media);
> + addDevice(std::move(media));
> return 0;
> }
>
> @@ -319,7 +319,7 @@ int DeviceEnumeratorUdev::addV4L2Device(dev_t devnum)
> LOG(DeviceEnumerator, Debug)
> << "All dependencies for media device "
> << deps->media_->deviceNode() << " found";
> - addDevice(deps->media_);
> + addDevice(std::move(deps->media_));
> pending_.remove(*deps);
> }
>
> diff --git a/src/libcamera/include/device_enumerator.h b/src/libcamera/include/device_enumerator.h
> index 770f42772270..433e357aebae 100644
> --- a/src/libcamera/include/device_enumerator.h
> +++ b/src/libcamera/include/device_enumerator.h
> @@ -44,8 +44,8 @@ public:
> std::shared_ptr<MediaDevice> search(const DeviceMatch &dm);
>
> protected:
> - std::shared_ptr<MediaDevice> createDevice(const std::string &deviceNode);
> - void addDevice(const std::shared_ptr<MediaDevice> &media);
> + std::unique_ptr<MediaDevice> createDevice(const std::string &deviceNode);
> + void addDevice(std::unique_ptr<MediaDevice> &&media);
> void removeDevice(const std::string &deviceNode);
>
> private:
> diff --git a/src/libcamera/include/device_enumerator_sysfs.h b/src/libcamera/include/device_enumerator_sysfs.h
> index 9063f6a75e11..5a5c9b0f5a31 100644
> --- a/src/libcamera/include/device_enumerator_sysfs.h
> +++ b/src/libcamera/include/device_enumerator_sysfs.h
> @@ -23,7 +23,7 @@ public:
> int enumerate();
>
> private:
> - int populateMediaDevice(const std::shared_ptr<MediaDevice> &media);
> + int populateMediaDevice(MediaDevice *media);
> std::string lookupDeviceNode(int major, int minor);
> };
>
> diff --git a/src/libcamera/include/device_enumerator_udev.h b/src/libcamera/include/device_enumerator_udev.h
> index efaefe5dc4a3..fdce4520f33a 100644
> --- a/src/libcamera/include/device_enumerator_udev.h
> +++ b/src/libcamera/include/device_enumerator_udev.h
> @@ -43,9 +43,9 @@ private:
> using DependencyMap = std::map<dev_t, std::list<MediaEntity *>>;
>
> struct MediaDeviceDeps {
> - MediaDeviceDeps(const std::shared_ptr<MediaDevice> &media,
> - const DependencyMap &deps)
> - : media_(media), deps_(deps)
> + MediaDeviceDeps(std::unique_ptr<MediaDevice> &&media,
> + DependencyMap &&deps)
> + : media_(std::move(media)), deps_(std::move(deps))
> {
> }
>
> @@ -54,7 +54,7 @@ private:
> return media_ == other.media_;
> }
>
> - std::shared_ptr<MediaDevice> media_;
> + std::unique_ptr<MediaDevice> media_;
> DependencyMap deps_;
> };
>
>
--
Regards
--
Kieran
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