[PATCH] CameraManager: Ensure we cleanup on failure

[Kieran Bingham]

If the CameraManager fails to initialise at startup during
CameraManager::Private::init(), then the run() function will prepare the
thread for operations, but the thread will immediately close without
executing any cleanup.

This can leave instantiated objects such as the EventNotifier registered
by the udev enumerator constructed in a thread which no longer exists.
The destructor of those objects can then fire an assertion that they are
being executed from an incorrect thread while performing their cleanup.

Ensure that the failure path does not result in reporting thread
ownership assertions by performing cleanup correctly on the
CameraManager thread before it closes.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>

---
This is the result of debugging an awkward error on an unrelated failure
path that caused the CameraManager to fail to construct:

"""
camera_sensor_legacy.cpp:850 'ar0144 2-0010': The analogue crop rectangle has been defaulted to the active area size
[1:49:26.079788375] [922]  WARN RkISP1Agc agc.cpp:46 'AeMeteringMode' parameter not found in tuning file
[1:49:26.079829125] [922]  WARN RkISP1Agc agc.cpp:69 No metering modes read from tuning file; defaulting to matrix
[1:49:26.080311125] [921] ERROR Camera camera_manager.cpp:350 Failed to start camera manager: No such file or directory
Failed to start camera manager: No such file or directory
[1:49:26.080547875] [921] ERROR Object object.cpp:252 EventNotifier can't be enabled from another thread
[1:49:26.080582375] [921] FATAL default object.cpp:253 assertion "false" failed in assertThreadBound()
Backtrace:
/usr/lib/libcamera-base.so.0.3(_ZN9libcamera6Object17assertThreadBoundEPKc+0xe4) [0xffffa35fd884]
/usr/lib/libcamera-base.so.0.3(_ZN9libcamera13EventNotifier10setEnabledEb+0x24) [0xffffa3601b34]
/usr/lib/libcamera-base.so.0.3(_ZN9libcamera13EventNotifierD2Ev+0x50) [0xffffa3601bf0]
/usr/lib/libcamera-base.so.0.3(_ZN9libcamera13EventNotifierD0Ev+0x18) [0xffffa3601cb8]
/usr/lib/libcamera.so.0.3(_ZN9libcamera20DeviceEnumeratorUdevD2Ev+0x38) [0xffffa3798698]
/usr/lib/libcamera.so.0.3(_ZN9libcamera20DeviceEnumeratorUdevD0Ev+0x18) [0xffffa3798738]
/usr/lib/libcamera.so.0.3(+0x997cc) [0xffffa36d97cc]
/usr/lib/libcamera.so.0.3(_ZN9libcamera13CameraManagerD1Ev+0x134) [0xffffa36d6f04]
/usr/lib/libcamera.so.0.3(_ZN9libcamera13CameraManagerD0Ev+0x18) [0xffffa36d6f78]
cam(+0x1ba60) [0xaaaad8d9ba60]
cam(+0x8b64) [0xaaaad8d88b64]
/usr/lib/libc.so.6(+0x284b4) [0xffffa30984b4]
/usr/lib/libc.so.6(__libc_start_main+0x9c) [0xffffa309858c]
cam(+0x8fb0) [0xaaaad8d88fb0]
Aborted (core dumped)
"""

Whilst the error "No such file or directory" reported above was out of
tree code causing the camera manager to fail - libcamera should not then
fail with an assertion after that while shutting down and calling
destructors.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 src/libcamera/camera_manager.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/libcamera/camera_manager.cpp b/src/libcamera/camera_manager.cpp
index 6280b2b3e485..a8b36bcea2d4 100644
--- a/src/libcamera/camera_manager.cpp
+++ b/src/libcamera/camera_manager.cpp
@@ -83,8 +83,10 @@ void CameraManager::Private::run()
 	mutex_.unlock();
 	cv_.notify_one();
 
-	if (ret < 0)
+	if (ret < 0) {
+		cleanup();
 		return;
+	}
 
 	/* Now start processing events and messages. */
 	exec();
-- 
2.47.0