[libcamera-devel] [PATCH v2 5/7] libcamera: camera: Add acquire() and release()
Niklas Söderlund
niklas.soderlund at ragnatech.se
Fri Jan 25 16:33:38 CET 2019
From: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
include/libcamera/camera.h | 5 +++++
src/libcamera/camera.cpp | 35 ++++++++++++++++++++++++++++++++++-
2 files changed, 39 insertions(+), 1 deletion(-)
diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
index a2ded62de94814c4..7e358f8c0aa093cf 100644
--- a/include/libcamera/camera.h
+++ b/include/libcamera/camera.h
@@ -29,6 +29,9 @@ public:
Signal<Camera *> disconnected;
+ int acquire();
+ void release();
+
private:
Camera(PipelineHandler *pipe, const std::string &name);
~Camera();
@@ -38,6 +41,8 @@ private:
std::shared_ptr<PipelineHandler> pipe_;
std::string name_;
+
+ bool acquired_;
};
} /* namespace libcamera */
diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
index 9cec289282e4797b..fd19e8cf6694cc1b 100644
--- a/src/libcamera/camera.cpp
+++ b/src/libcamera/camera.cpp
@@ -102,7 +102,7 @@ const std::string &Camera::name() const
*/
Camera::Camera(PipelineHandler *pipe, const std::string &name)
- : pipe_(pipe->shared_from_this()), name_(name)
+ : pipe_(pipe->shared_from_this()), name_(name), acquired_(false)
{
}
@@ -127,4 +127,37 @@ void Camera::disconnect()
disconnected.emit(this);
}
+/**
+ * \brief Acquire the camera device for exclusive access
+ *
+ * After opening the device with open(), exclusive access must be obtained
+ * before performing operations that change the device state. This function is
+ * not blocking, if the device has already been acquired (by the same or another
+ * process) the -EBUSY error code is returned.
+ *
+ * Once exclusive access isn't needed anymore, the device should be released
+ * with a call to the release() function.
+ *
+ * \return 0 on success or a negative error code on error.
+ */
+int Camera::acquire()
+{
+ if (acquired_)
+ return -EBUSY;
+
+ acquired_ = true;
+ return 0;
+}
+
+/**
+ * \brief Release exclusive access to the camera device
+ *
+ * Releasing the camera device allows other users to acquire exclusive access
+ * with the acquire() function.
+ */
+void Camera::release()
+{
+ acquired_ = false;
+}
+
} /* namespace libcamera */
--
2.20.1
More information about the libcamera-devel
mailing list