[libcamera-devel] [PATCH RFC 2/2] android: CameraHalManager: Create a static object dynamically

[Hirokazu Honda]

Originally CameraHalManager is created in the libcamera start up
and destroyed in the libcamera termination. However,
CameraHalManager destructor can access  other static objects that
has been destroyed.
Avoid this issue by destroying CameraHalManager when tear_down() is
called in ChromeOS or leaking it in other platforms.

Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
---
 src/android/camera3_hal.cpp        | 14 +++++++-------
 src/android/camera_hal_manager.cpp |  7 +++++++
 src/android/camera_hal_manager.h   |  5 ++++-
 3 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/src/android/camera3_hal.cpp b/src/android/camera3_hal.cpp
index f2d4799f..59d51ed5 100644
--- a/src/android/camera3_hal.cpp
+++ b/src/android/camera3_hal.cpp
@@ -24,25 +24,23 @@ using namespace libcamera;
 
 LOG_DEFINE_CATEGORY(HAL)
 
-static CameraHalManager cameraManager;
-
 /*------------------------------------------------------------------------------
  * Android Camera HAL callbacks
  */
 
 static int hal_get_number_of_cameras()
 {
-	return cameraManager.numCameras();
+	return CameraHalManager::instance()->numCameras();
 }
 
 static int hal_get_camera_info(int id, struct camera_info *info)
 {
-	return cameraManager.getCameraInfo(id, info);
+	return CameraHalManager::instance()->getCameraInfo(id, info);
 }
 
 static int hal_set_callbacks(const camera_module_callbacks_t *callbacks)
 {
-	cameraManager.setCallbacks(callbacks);
+	CameraHalManager::instance()->setCallbacks(callbacks);
 
 	return 0;
 }
@@ -70,7 +68,7 @@ static int hal_init()
 {
 	LOG(HAL, Info) << "Initialising Android camera HAL";
 
-	cameraManager.init();
+	CameraHalManager::instance()->init();
 
 	return 0;
 }
@@ -85,7 +83,8 @@ static int hal_dev_open(const hw_module_t *module, const char *name,
 	LOG(HAL, Debug) << "Open camera " << name;
 
 	int id = atoi(name);
-	auto [camera, ret] = cameraManager.open(id, module);
+
+	auto [camera, ret] = CameraHalManager::instance()->open(id, module);
 	if (!camera) {
 		LOG(HAL, Error)
 			<< "Failed to open camera module '" << id << "'";
@@ -135,6 +134,7 @@ static void set_up(cros::CameraMojoChannelManagerToken *token)
 
 static void tear_down()
 {
+	delete CameraHalManager::instance();
 }
 
 cros::cros_camera_hal_t CROS_CAMERA_EXPORT CROS_CAMERA_HAL_INFO_SYM = {
diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
index bf3fcda7..387b600d 100644
--- a/src/android/camera_hal_manager.cpp
+++ b/src/android/camera_hal_manager.cpp
@@ -37,6 +37,13 @@ CameraHalManager::CameraHalManager()
 /* CameraManager calls stop() in the destructor. */
 CameraHalManager::~CameraHalManager() = default;
 
+/* static */
+CameraHalManager *CameraHalManager::instance()
+{
+	static CameraHalManager *cameraHalManager = new CameraHalManager;
+	return cameraHalManager;
+}
+
 int CameraHalManager::init()
 {
 	cameraManager_ = std::make_unique<CameraManager>();
diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
index d9bf2798..9b43afc4 100644
--- a/src/android/camera_hal_manager.h
+++ b/src/android/camera_hal_manager.h
@@ -24,9 +24,10 @@ class CameraDevice;
 class CameraHalManager
 {
 public:
-	CameraHalManager();
 	~CameraHalManager();
 
+	static CameraHalManager *instance();
+
 	int init();
 
 	std::tuple<CameraDevice *, int>
@@ -42,6 +43,8 @@ private:
 
 	static constexpr unsigned int firstExternalCameraId_ = 1000;
 
+	CameraHalManager();
+
 	static int32_t cameraLocation(const libcamera::Camera *cam);
 
 	void cameraAdded(std::shared_ptr<libcamera::Camera> cam);
-- 
2.31.1.818.g46aad6cb9e-goog