[libcamera-devel] [PATCH v3 07/11] libcamera: camera: Report function which fails access control

[Kieran Bingham]

The camera object has a state machine to ensure calls are only made
when in the correct state. It isn't easy to identify where things happen
when assertions fail so add extra information to make this clearer.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 src/libcamera/camera.cpp | 51 +++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 21 deletions(-)

diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
index b86bff4745b2..336ab8695ab3 100644
--- a/src/libcamera/camera.cpp
+++ b/src/libcamera/camera.cpp
@@ -346,8 +346,9 @@ public:
 		const std::set<Stream *> &streams);
 	~Private();
 
-	int isAccessAllowed(State state, bool allowDisconnected = false) const;
-	int isAccessAllowed(State low, State high,
+	int isAccessAllowed(const char *from, State state,
+			    bool allowDisconnected = false) const;
+	int isAccessAllowed(const char *from, State low, State high,
 			    bool allowDisconnected = false) const;
 
 	void disconnect();
@@ -384,7 +385,8 @@ static const char *const camera_state_names[] = {
 	"Running",
 };
 
-int Camera::Private::isAccessAllowed(State state, bool allowDisconnected) const
+int Camera::Private::isAccessAllowed(const char *from, State state,
+				     bool allowDisconnected) const
 {
 	if (!allowDisconnected && disconnected_)
 		return -ENODEV;
@@ -395,14 +397,16 @@ int Camera::Private::isAccessAllowed(State state, bool allowDisconnected) const
 
 	ASSERT(static_cast<unsigned int>(state) < std::size(camera_state_names));
 
-	LOG(Camera, Debug) << "Camera in " << camera_state_names[currentState]
-			   << " state trying operation requiring state "
-			   << camera_state_names[state];
+	LOG(Camera, Warning) << "Camera in " << camera_state_names[currentState]
+			     << " state trying operation ["
+			     << from << "] requiring state "
+			     << camera_state_names[state];
 
 	return -EACCES;
 }
 
-int Camera::Private::isAccessAllowed(State low, State high,
+int Camera::Private::isAccessAllowed(const char *from,
+				     State low, State high,
 				     bool allowDisconnected) const
 {
 	if (!allowDisconnected && disconnected_)
@@ -415,10 +419,11 @@ int Camera::Private::isAccessAllowed(State low, State high,
 	ASSERT(static_cast<unsigned int>(low) < std::size(camera_state_names) &&
 	       static_cast<unsigned int>(high) < std::size(camera_state_names));
 
-	LOG(Camera, Debug) << "Camera in " << camera_state_names[currentState]
-			   << " state trying operation requiring state between "
-			   << camera_state_names[low] << " and "
-			   << camera_state_names[high];
+	LOG(Camera, Warning) << "Camera in " << camera_state_names[currentState]
+			     << " state trying operation [" << from
+			     << "] requiring state between "
+			     << camera_state_names[low] << " and "
+			     << camera_state_names[high];
 
 	return -EACCES;
 }
@@ -646,7 +651,7 @@ int Camera::exportFrameBuffers(Stream *stream,
 {
 	Private *const d = LIBCAMERA_D_PTR();
 
-	int ret = d->isAccessAllowed(Private::CameraConfigured);
+	int ret = d->isAccessAllowed(__FUNCTION__, Private::CameraConfigured);
 	if (ret < 0)
 		return ret;
 
@@ -693,7 +698,7 @@ int Camera::acquire()
 	 * No manual locking is required as PipelineHandler::lock() is
 	 * thread-safe.
 	 */
-	int ret = d->isAccessAllowed(Private::CameraAvailable);
+	int ret = d->isAccessAllowed(__FUNCTION__, Private::CameraAvailable);
 	if (ret < 0)
 		return ret == -EACCES ? -EBUSY : ret;
 
@@ -726,7 +731,8 @@ int Camera::release()
 {
 	Private *const d = LIBCAMERA_D_PTR();
 
-	int ret = d->isAccessAllowed(Private::CameraAvailable,
+	int ret = d->isAccessAllowed(__FUNCTION__,
+				     Private::CameraAvailable,
 				     Private::CameraConfigured, true);
 	if (ret < 0)
 		return ret == -EACCES ? -EBUSY : ret;
@@ -805,7 +811,8 @@ std::unique_ptr<CameraConfiguration> Camera::generateConfiguration(const StreamR
 {
 	Private *const d = LIBCAMERA_D_PTR();
 
-	int ret = d->isAccessAllowed(Private::CameraAvailable,
+	int ret = d->isAccessAllowed(__FUNCTION__,
+				     Private::CameraAvailable,
 				     Private::CameraRunning);
 	if (ret < 0)
 		return nullptr;
@@ -866,7 +873,8 @@ int Camera::configure(CameraConfiguration *config)
 {
 	Private *const d = LIBCAMERA_D_PTR();
 
-	int ret = d->isAccessAllowed(Private::CameraAcquired,
+	int ret = d->isAccessAllowed(__FUNCTION__,
+				     Private::CameraAcquired,
 				     Private::CameraConfigured);
 	if (ret < 0)
 		return ret;
@@ -938,7 +946,8 @@ std::unique_ptr<Request> Camera::createRequest(uint64_t cookie)
 {
 	Private *const d = LIBCAMERA_D_PTR();
 
-	int ret = d->isAccessAllowed(Private::CameraConfigured,
+	int ret = d->isAccessAllowed(__FUNCTION__,
+				     Private::CameraConfigured,
 				     Private::CameraRunning);
 	if (ret < 0)
 		return nullptr;
@@ -972,7 +981,7 @@ int Camera::queueRequest(Request *request)
 {
 	Private *const d = LIBCAMERA_D_PTR();
 
-	int ret = d->isAccessAllowed(Private::CameraRunning);
+	int ret = d->isAccessAllowed(__FUNCTION__, Private::CameraRunning);
 	if (ret < 0)
 		return ret;
 
@@ -1022,7 +1031,7 @@ int Camera::start(const ControlList *controls)
 {
 	Private *const d = LIBCAMERA_D_PTR();
 
-	int ret = d->isAccessAllowed(Private::CameraConfigured);
+	int ret = d->isAccessAllowed(__FUNCTION__, Private::CameraConfigured);
 	if (ret < 0)
 		return ret;
 
@@ -1056,7 +1065,7 @@ int Camera::stop()
 {
 	Private *const d = LIBCAMERA_D_PTR();
 
-	int ret = d->isAccessAllowed(Private::CameraRunning);
+	int ret = d->isAccessAllowed(__FUNCTION__, Private::CameraRunning);
 	if (ret < 0)
 		return ret;
 
@@ -1082,7 +1091,7 @@ void Camera::requestComplete(Request *request)
 	Private *const d = LIBCAMERA_D_PTR();
 
 	/* Disconnected cameras are still able to complete requests. */
-	int ret = d->isAccessAllowed(Private::CameraRunning);
+	int ret = d->isAccessAllowed(__FUNCTION__, Private::CameraRunning);
 	if (ret < 0 && ret != -ENODEV)
 		LOG(Camera, Fatal) << "Trying to complete a request when stopped";
 
-- 
2.25.1