[libcamera-devel] [PATCH v2 2/4] libcamera: camera_manager: Move {add, remove}Camera to internal

Kieran Bingham kieran.bingham at ideasonboard.com
Sat May 13 17:37:04 CEST 2023


Quoting Jacopo Mondi via libcamera-devel (2023-05-13 15:57:45)
> Hi Kieran
> 
> On Thu, May 11, 2023 at 11:58:31PM +0100, Kieran Bingham via libcamera-devel wrote:
> > The CameraManager exposes addCamera and removeCamera as public API
> > calls, while they should never be called from an application. These
> > calls are only expected to be used by PipelineHandlers to update the
> > CameraManager that a new Camera has been created and allow the Camera
> > Manager to expose it to applications.
> >
> > Remove the public calls and update the private implementations such that
> > they can be used directly by the PipelineHandler through the internal
> > CameraManager::Private provided by the Extensible class.
> >
> > Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> > ---
> >  include/libcamera/camera_manager.h          |  4 -
> >  include/libcamera/internal/camera_manager.h |  2 +-
> >  src/libcamera/camera_manager.cpp            | 87 +++++++++------------
> >  src/libcamera/pipeline_handler.cpp          |  6 +-
> >  4 files changed, 43 insertions(+), 56 deletions(-)
> >
> > diff --git a/include/libcamera/camera_manager.h b/include/libcamera/camera_manager.h
> > index 4b1fb7568e83..9767acc42c89 100644
> > --- a/include/libcamera/camera_manager.h
> > +++ b/include/libcamera/camera_manager.h
> > @@ -34,10 +34,6 @@ public:
> >       std::shared_ptr<Camera> get(const std::string &id);
> >       std::shared_ptr<Camera> get(dev_t devnum);
> >
> > -     void addCamera(std::shared_ptr<Camera> camera,
> > -                    const std::vector<dev_t> &devnums);
> > -     void removeCamera(std::shared_ptr<Camera> camera);
> > -
> >       static const std::string &version() { return version_; }
> >
> >       Signal<std::shared_ptr<Camera>> cameraAdded;
> > diff --git a/include/libcamera/internal/camera_manager.h b/include/libcamera/internal/camera_manager.h
> > index 4bba3ac2eb29..8386e90e0f60 100644
> > --- a/include/libcamera/internal/camera_manager.h
> > +++ b/include/libcamera/internal/camera_manager.h
> > @@ -31,7 +31,7 @@ public:
> >       int start();
> >       void addCamera(std::shared_ptr<Camera> camera,
> >                      const std::vector<dev_t> &devnums) LIBCAMERA_TSA_EXCLUDES(mutex_);
> > -     void removeCamera(Camera *camera) LIBCAMERA_TSA_EXCLUDES(mutex_);
> > +     void removeCamera(std::shared_ptr<Camera> camera) LIBCAMERA_TSA_EXCLUDES(mutex_);
> >
> >       /*
> >        * This mutex protects
> > diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
> > index b95284ba5a80..34f09a4d181b 100644
> > --- a/src/libcamera/camera_manager.cpp
> > +++ b/src/libcamera/camera_manager.cpp
> > @@ -148,9 +148,25 @@ void CameraManager::Private::cleanup()
> >       enumerator_.reset(nullptr);
> >  }
> >
> > +/**
> > + * \brief Add a camera to the camera manager
> > + * \param[in] camera The camera to be added
> > + * \param[in] devnums The device numbers to associate with \a camera
> > + *
> > + * This function is called by pipeline handlers to register the cameras they
> > + * handle with the camera manager. Registered cameras are immediately made
> > + * available to the system.
> > + *
> > + * \a devnums are used by the V4L2 compatibility layer to map V4L2 device nodes
> > + * to Camera instances.
> > + *
> > + * \context This function shall be called from the CameraManager thread.
> > + */
> >  void CameraManager::Private::addCamera(std::shared_ptr<Camera> camera,
> >                                      const std::vector<dev_t> &devnums)
> >  {
> > +     ASSERT(Thread::current() == this);
> > +
> 
> Is this still needed now that this function is only available to the
> internal library componentes ?

It was there before, and will be compiled out for release so I don't
think it hurts. If anything it ensures the same guarantee for new
pipeline handlers that get developed, so I'd keep it, (and the others).


> 
> >       MutexLocker locker(mutex_);
> >
> >       for (const std::shared_ptr<Camera> &c : cameras_) {
> > @@ -167,15 +183,31 @@ void CameraManager::Private::addCamera(std::shared_ptr<Camera> camera,
> >       unsigned int index = cameras_.size() - 1;
> >       for (dev_t devnum : devnums)
> >               camerasByDevnum_[devnum] = cameras_[index];
> > +
> > +     /* Report the addition to the public signal */
> > +     CameraManager *const o = LIBCAMERA_O_PTR();
> > +     o->cameraAdded.emit(cameras_[index]);
> >  }
> >
> > -void CameraManager::Private::removeCamera(Camera *camera)
> > +/**
> > + * \brief Remove a camera from the camera manager
> > + * \param[in] camera The camera to be removed
> > + *
> > + * This function is called by pipeline handlers to unregister cameras from the
> > + * camera manager. Unregistered cameras won't be reported anymore by the
> > + * cameras() and get() calls, but references may still exist in applications.
> > + *
> > + * \context This function shall be called from the CameraManager thread.
> 
> ditto as per above
> 
> > + */
> > +void CameraManager::Private::removeCamera(std::shared_ptr<Camera> camera)
> >  {
> > +     ASSERT(Thread::current() == this);
> > +
> 
> same here
> 
> >       MutexLocker locker(mutex_);
> >
> >       auto iter = std::find_if(cameras_.begin(), cameras_.end(),
> >                                [camera](std::shared_ptr<Camera> &c) {
> > -                                      return c.get() == camera;
> > +                                      return c.get() == camera.get();
> >                                });
> >       if (iter == cameras_.end())
> >               return;
> > @@ -185,12 +217,16 @@ void CameraManager::Private::removeCamera(Camera *camera)
> >
> >       auto iter_d = std::find_if(camerasByDevnum_.begin(), camerasByDevnum_.end(),
> >                                  [camera](const std::pair<dev_t, std::weak_ptr<Camera>> &p) {
> > -                                        return p.second.lock().get() == camera;
> > +                                        return p.second.lock().get() == camera.get();
> >                                  });
> >       if (iter_d != camerasByDevnum_.end())
> >               camerasByDevnum_.erase(iter_d);
> >
> >       cameras_.erase(iter);
> > +
> > +     /* Report the removal to the public signal */
> > +     CameraManager *const o = LIBCAMERA_O_PTR();
> > +     o->cameraRemoved.emit(camera);
> >  }
> >
> >  /**
> > @@ -383,51 +419,6 @@ std::shared_ptr<Camera> CameraManager::get(dev_t devnum)
> >   * perform any blocking operation.
> >   */
> >
> > -/**
> > - * \brief Add a camera to the camera manager
> > - * \param[in] camera The camera to be added
> > - * \param[in] devnums The device numbers to associate with \a camera
> > - *
> > - * This function is called by pipeline handlers to register the cameras they
> > - * handle with the camera manager. Registered cameras are immediately made
> > - * available to the system.
> > - *
> > - * \a devnums are used by the V4L2 compatibility layer to map V4L2 device nodes
> > - * to Camera instances.
> > - *
> > - * \context This function shall be called from the CameraManager thread.
> > - */
> > -void CameraManager::addCamera(std::shared_ptr<Camera> camera,
> > -                           const std::vector<dev_t> &devnums)
> > -{
> > -     Private *const d = _d();
> > -
> > -     ASSERT(Thread::current() == d);
> > -
> > -     d->addCamera(camera, devnums);
> > -     cameraAdded.emit(camera);
> > -}
> > -
> > -/**
> > - * \brief Remove a camera from the camera manager
> > - * \param[in] camera The camera to be removed
> > - *
> > - * This function is called by pipeline handlers to unregister cameras from the
> > - * camera manager. Unregistered cameras won't be reported anymore by the
> > - * cameras() and get() calls, but references may still exist in applications.
> > - *
> > - * \context This function shall be called from the CameraManager thread.
> > - */
> > -void CameraManager::removeCamera(std::shared_ptr<Camera> camera)
> > -{
> > -     Private *const d = _d();
> > -
> > -     ASSERT(Thread::current() == d);
> > -
> > -     d->removeCamera(camera.get());
> > -     cameraRemoved.emit(camera);
> > -}
> > -
> >  /**
> >   * \fn const std::string &CameraManager::version()
> >   * \brief Retrieve the libcamera version string
> > diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
> > index f72613b8e515..49092ea88a58 100644
> > --- a/src/libcamera/pipeline_handler.cpp
> > +++ b/src/libcamera/pipeline_handler.cpp
> > @@ -16,10 +16,10 @@
> >  #include <libcamera/base/utils.h>
> >
> >  #include <libcamera/camera.h>
> > -#include <libcamera/camera_manager.h>
> >  #include <libcamera/framebuffer.h>
> >
> >  #include "libcamera/internal/camera.h"
> > +#include "libcamera/internal/camera_manager.h"
> >  #include "libcamera/internal/device_enumerator.h"
> >  #include "libcamera/internal/framebuffer.h"
> >  #include "libcamera/internal/media_device.h"
> > @@ -624,7 +624,7 @@ void PipelineHandler::registerCamera(std::shared_ptr<Camera> camera)
> >               }
> >       }
> >
> > -     manager_->addCamera(std::move(camera), devnums);
> > +     manager_->_d()->addCamera(std::move(camera), devnums);
> >  }
> >
> >  /**
> > @@ -691,7 +691,7 @@ void PipelineHandler::disconnect()
> >                       continue;
> >
> >               camera->disconnect();
> > -             manager_->removeCamera(camera);
> > +             manager_->_d()->removeCamera(camera);
> 
> All minors as well
> Reviewed-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>
> 
> Thanks
>    j
> 
> >       }
> >  }
> >
> > --
> > 2.34.1
> >


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