diff options
| -rw-r--r-- | include/libcamera/internal/pipeline_handler.h | 3 | ||||
| -rw-r--r-- | src/libcamera/camera.cpp | 2 | ||||
| -rw-r--r-- | src/libcamera/pipeline_handler.cpp | 48 |
3 files changed, 43 insertions, 10 deletions
diff --git a/include/libcamera/internal/pipeline_handler.h b/include/libcamera/internal/pipeline_handler.h index cad5812f..597f7c3e 100644 --- a/include/libcamera/internal/pipeline_handler.h +++ b/include/libcamera/internal/pipeline_handler.h @@ -45,7 +45,7 @@ public: MediaDevice *acquireMediaDevice(DeviceEnumerator *enumerator, const DeviceMatch &dm); - bool acquire(); + bool acquire(Camera *camera); void release(Camera *camera); virtual std::unique_ptr<CameraConfiguration> generateConfiguration(Camera *camera, @@ -79,6 +79,7 @@ protected: virtual int queueRequestDevice(Camera *camera, Request *request) = 0; virtual void stopDevice(Camera *camera) = 0; + virtual bool acquireDevice(Camera *camera); virtual void releaseDevice(Camera *camera); CameraManager *manager_; diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp index 382a68f7..4e393f89 100644 --- a/src/libcamera/camera.cpp +++ b/src/libcamera/camera.cpp @@ -995,7 +995,7 @@ int Camera::acquire() if (ret < 0) return ret == -EACCES ? -EBUSY : ret; - if (!d->pipe_->acquire()) { + if (!d->pipe_->acquire(this)) { LOG(Camera, Info) << "Pipeline handler in use by another process"; return -EBUSY; diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp index 1fc22d6a..861815cb 100644 --- a/src/libcamera/pipeline_handler.cpp +++ b/src/libcamera/pipeline_handler.cpp @@ -163,20 +163,24 @@ MediaDevice *PipelineHandler::acquireMediaDevice(DeviceEnumerator *enumerator, * has already acquired it * \sa release() */ -bool PipelineHandler::acquire() +bool PipelineHandler::acquire(Camera *camera) { MutexLocker locker(lock_); - if (useCount_) { - ++useCount_; - return true; + if (useCount_ == 0) { + for (std::shared_ptr<MediaDevice> &media : mediaDevices_) { + if (!media->lock()) { + unlockMediaDevices(); + return false; + } + } } - for (std::shared_ptr<MediaDevice> &media : mediaDevices_) { - if (!media->lock()) { + if (!acquireDevice(camera)) { + if (useCount_ == 0) unlockMediaDevices(); - return false; - } + + return false; } ++useCount_; @@ -214,11 +218,39 @@ void PipelineHandler::release(Camera *camera) } /** + * \brief Acquire resources associated with this camera + * \param[in] camera The camera for which to acquire resources + * + * Pipeline handlers may override this in order to get resources such as opening + * devices and allocating buffers when a camera is acquired. + * + * This is used by the uvcvideo pipeline handler to delay opening /dev/video# + * until the camera is acquired to avoid excess power consumption. The delayed + * opening of /dev/video# is a special case because the kernel uvcvideo driver + * powers on the USB device as soon as /dev/video# is opened. This behavior + * should *not* be copied by other pipeline handlers. + * + * \return True on success, false on failure + * \sa releaseDevice() + */ +bool PipelineHandler::acquireDevice([[maybe_unused]] Camera *camera) +{ + return true; +} + +/** * \brief Release resources associated with this camera * \param[in] camera The camera for which to release resources * * Pipeline handlers may override this in order to perform cleanup operations * when a camera is released, such as freeing memory. + * + * This is called once for every camera that is released. If there are resources + * shared by multiple cameras then the pipeline handler must take care to not + * release them until releaseDevice() has been called for all previously + * acquired cameras. + * + * \sa acquireDevice() */ void PipelineHandler::releaseDevice([[maybe_unused]] Camera *camera) { |