[libcamera-devel] [RFC PATCH 3/6] android: camera_hal_manager: Add thread safety annotation

[Hirokazu Honda]

This applies clang thread safety annotation to CameraHalManager.
Mutex and MutexLocker there are replaced with Mutex2 and
MutexLocer2.

Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
---
 src/android/camera_hal_manager.cpp | 10 +++++-----
 src/android/camera_hal_manager.h   | 14 ++++++--------
 2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
index 5f7bfe26..26715a5f 100644
--- a/src/android/camera_hal_manager.cpp
+++ b/src/android/camera_hal_manager.cpp
@@ -75,7 +75,7 @@ int CameraHalManager::init()
 std::tuple<CameraDevice *, int>
 CameraHalManager::open(unsigned int id, const hw_module_t *hardwareModule)
 {
-	MutexLocker locker(mutex_);
+	MutexLocker2 locker(mutex_);
 
 	if (!callbacks_) {
 		LOG(HAL, Error) << "Can't open camera before callbacks are set";
@@ -103,7 +103,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
 	bool isCameraExternal = false;
 	bool isCameraNew = false;
 
-	MutexLocker locker(mutex_);
+	MutexLocker2 locker(mutex_);
 
 	/*
 	 * Each camera is assigned a unique integer ID when it is seen for the
@@ -198,7 +198,7 @@ void CameraHalManager::cameraAdded(std::shared_ptr<Camera> cam)
 
 void CameraHalManager::cameraRemoved(std::shared_ptr<Camera> cam)
 {
-	MutexLocker locker(mutex_);
+	MutexLocker2 locker(mutex_);
 
 	auto iter = std::find_if(cameras_.begin(), cameras_.end(),
 				 [&cam](const std::unique_ptr<CameraDevice> &camera) {
@@ -257,7 +257,7 @@ int CameraHalManager::getCameraInfo(unsigned int id, struct camera_info *info)
 	if (!info)
 		return -EINVAL;
 
-	MutexLocker locker(mutex_);
+	MutexLocker2 locker(mutex_);
 
 	CameraDevice *camera = cameraDeviceFromHalId(id);
 	if (!camera) {
@@ -280,7 +280,7 @@ void CameraHalManager::setCallbacks(const camera_module_callbacks_t *callbacks)
 {
 	callbacks_ = callbacks;
 
-	MutexLocker locker(mutex_);
+	MutexLocker2 locker(mutex_);
 
 	/*
 	 * Some external cameras may have been identified before the callbacks_
diff --git a/src/android/camera_hal_manager.h b/src/android/camera_hal_manager.h
index 3f6d302a..9b8c3a1f 100644
--- a/src/android/camera_hal_manager.h
+++ b/src/android/camera_hal_manager.h
@@ -8,7 +8,6 @@
 #define __ANDROID_CAMERA_MANAGER_H__
 
 #include <map>
-#include <mutex>
 #include <stddef.h>
 #include <tuple>
 #include <vector>
@@ -18,6 +17,8 @@
 #include <system/camera_metadata.h>
 
 #include <libcamera/base/class.h>
+#include <libcamera/base/mutex.h>
+#include <libcamera/base/thread_annotations.h>
 
 #include <libcamera/camera_manager.h>
 
@@ -44,9 +45,6 @@ public:
 private:
 	LIBCAMERA_DISABLE_COPY_AND_MOVE(CameraHalManager)
 
-	using Mutex = std::mutex;
-	using MutexLocker = std::unique_lock<std::mutex>;
-
 	static constexpr unsigned int firstExternalCameraId_ = 1000;
 
 	CameraHalManager();
@@ -56,15 +54,15 @@ private:
 	void cameraAdded(std::shared_ptr<libcamera::Camera> cam);
 	void cameraRemoved(std::shared_ptr<libcamera::Camera> cam);
 
-	CameraDevice *cameraDeviceFromHalId(unsigned int id);
+	CameraDevice *cameraDeviceFromHalId(unsigned int id) REQUIRES(mutex_);
 
 	std::unique_ptr<libcamera::CameraManager> cameraManager_;
 	CameraHalConfig halConfig_;
 
 	const camera_module_callbacks_t *callbacks_;
-	std::vector<std::unique_ptr<CameraDevice>> cameras_;
-	std::map<std::string, unsigned int> cameraIdsMap_;
-	Mutex mutex_;
+	std::vector<std::unique_ptr<CameraDevice>> cameras_ GUARDED_BY(mutex_);
+	std::map<std::string, unsigned int> cameraIdsMap_ GUARDED_BY(mutex_);
+	libcamera::Mutex2 mutex_;
 
 	unsigned int numInternalCameras_;
 	unsigned int nextExternalCameraId_;
-- 
2.33.1.1089.g2158813163f-goog