The V4L2 compatibility layer will need a way to map device numbers to
libcamera Camera instances. Expose a method in the camera manager to
retrieve Camera instances by devnum. The mapping from device numbers to
Camera instances is optionally declared by pipeline handlers when they
register cameras with the camera manager.
Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The CameraManager class is not supposed to be instantiated multiple
times, which led to a singleton implementation. This requires a global
instance of the CameraManager, which is destroyed when the global
destructors are executed.
Relying on global instances causes issues with cleanup, as the order in
which the global destructors are run can't be controlled. In particular,
the Android camera HAL implementation ends up destroying the
CameraHalManager after the CameraManager, which leads to use-after-free
problems.
To solve this, remove the CameraManager::instance() method and make the
CameraManager class instantiable directly. Multiple instances are still
not allowed, and this is enforced by storing the instance pointer
internally to be checked when an instance is created.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
The CameraManager class uses the event dispatcher of the current thread.
This makes the CameraManager::eventDispatcher() and
CameraManager::setEventDispatcher() methods inconsistent, as they access
different event dispatcher instances depending on the calling thread.
Fix this by inheriting from the Object class, which binds the
CameraManager to a thread, and use the event dispatcher of the bound
thread.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
The new Thread class wraps std::thread in order to integrate it with the
Object, Signal and EventDispatcher classes. By default new threads run
an internal event loop, and their run() method can be overloaded to
provide a custom thread loop.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Commit b817bcec6b ("libcamera: Auto generate version information")
generates version information in order to automatically include it
various locations (Sphinx and Doxygen documentation, libcamera::version
variable available at runtime, and version.h available at compile time).
Unfortunately this causes lots of unnecessary rebuilds when modifying
the git tree state, which hinders development.
The problem is caused by the generated version.h being listed as a
dependency for the whole libcamera. This is required as meson (to the
best of my knowledge) doesn't provide a way to explicitly specify the
dependency of a single object file (camera_manager.o in this case, as
camera_manager.cpp is the only consumer of the generated version string)
on the custom target used to generate version.h. The dependency can't be
automatically detected at build time, like dependencies on normal
headers that are generated by parsing the source, because the version.h
header may not exist yet. The build could then fail in a racy way.
This change attempts at solving the issue by generating a version.cpp
instead of a version.h to set the git-based version. This minimises the
number of files that need to be rebuild when then git tree state
changes, while retaining the main purpose of the original automatic
version generation, the ability to access the git-based version string
at runtime. We however lose the ability to access git-based version
information at build time in an application building against libcamera,
but there is no expected use case for this.
The version string is moved from the libcamera namespace to the
CameraManager class in order to avoid including version.h inside
libcamera (in version.cpp and in camera_manager.cpp), which would create
dependencies causing more rebuild steps, as described above.
On the other hand, major, minor and patch level version numbers are
useful at build time. This commit changes the generation of version.h in
order to add three macros named LIBCAMERA_VERSION_MAJOR,
LIBCAMERA_VERSION_MINOR and LIBCAMERA_VERSION_PATCH for this purpose.
version.h is not included by any other libcamera header or source file,
and thus doesn't force a rebuild of the library.
The Sphinx and Doxygen documentation keep their git-based version
information, which is set during the configuration of the build and then
doesn't track git commits. We may want to investigate how to improve
this, but given that git-based version for the documentation has very
few use cases outside of tagging nightly builds, this isn't considered
an issue at the moment.
The documentation install directory now uses the base version string, in
order to avoid increasing the number of documentation directories
needlessly. This shouldn't cause any issue as the API should not change
without a change to the version number.
The version number generation and handling code now also standardises
the version variables to not start with a 'v' prefix in meson, in order
to simplify their handling. The prefix is added when generating the
relevant files.
Note that we go back to specifying the fallback version in the main
meson.build, in the call to the project() function. For the time being I
believe this should be a good compromise to avoid unnecessary
recompilation, and moving the fallback version to a different file for
tarball releases can be built on top of this.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The class assignment operator is usually defined as returning a
reference to the object, to allow a = b = c statements. While the return
type makes no difference when deleting the operator in a class
definition, it's still a good practice to use the correct return type.
Fix it in the Camera and CameraManager classes.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
The new removeCamera() method is meant to be used by pipeline handlers
to unregister a camera in case of device disconnection.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
The PipelineHandler which creates a Camera is responsible for serving
any operation requested by the user. In order forward the public API
calls, the camera needs to store a reference to its pipeline handler.
Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes since v1:
- Create pipeline handlers is shared pointers, make them inherit from
std::enable_shared_from_this<> and stored them in shared pointers.
The Camera class is explicitly reference-counted to manage the lifetime
of camera objects. Replace this open-coded implementation with usage of
the std::shared_ptr<> class.
This API change prevents pipeline handlers from subclassing the Camera
class. This isn't deemed to be an issue. Mark the class final to make
this explicit.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Cameras are listed through a double indirection, first iterating over
all available pipeline handlers, and then listing the cameras they each
support. To simplify the API make the pipeline handlers register the
cameras with the camera manager directly, which lets the camera manager
easily expose the list of all available cameras.
The PipelineHandler API gets simplified as the handlers don't need to
expose the list of cameras they have created.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Convey the fact that the CameraManager class owns the DeviceEnumerator
instance it creates by using std::unique_ptr<> to store the pointer.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Add three new classes, EventDispatcher, EventNotifier and Timer, that
define APIs for file descriptor event notification and timers. The
implementation of the EventDispatcher is meant to be provided to
libcamera by the application.
The event dispatcher is integrated twith the camera manager to implement
automatic registration of timers and events.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
There can only be a single camera manager instance in the application.
Creating it as a singleton helps avoiding mistakes. It also allows the
camera manager to be used as a storage of global data, such as the
future event dispatcher.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
