libcamera: base: thread: Use std::unique_ptr instead of raw pointer

An `std::unique_ptr` is safer and expresses the intent better, so use that.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

include/libcamera/base/thread.h

@@ -75,7 +75,7 @@ private:
 			ThreadData *targetData);
 
 	std::thread thread_;
-	ThreadData *data_;
+	std::unique_ptr<ThreadData> data_;
 };
 
 } /* namespace libcamera */

src/libcamera/base/thread.cpp

@@ -105,8 +105,12 @@ public:
 class ThreadData
 {
 public:
-	ThreadData()
-		: thread_(nullptr), running_(false), dispatcher_(nullptr)
+	/**
+	 * \brief Constructor for internal thread data
+	 * \param[in] thread The associated thread
+	 */
+	ThreadData(Thread *thread)
+		: thread_(thread), running_(false), dispatcher_(nullptr)
 	{
 	}
 
@@ -167,7 +171,7 @@ ThreadData *ThreadData::current()
 	 * The main thread doesn't receive thread-local data when it is
 	 * started, set it here.
 	 */
-	ThreadData *data = mainThread.data_;
+	ThreadData *data = mainThread.data_.get();
 	data->tid_ = syscall(SYS_gettid);
 	currentThreadData = data;
 	return data;
@@ -231,15 +235,13 @@ ThreadData *ThreadData::current()
  * \brief Create a thread
  */
 Thread::Thread()
+	: data_(std::make_unique<ThreadData>(this))
 {
-	data_ = new ThreadData;
-	data_->thread_ = this;
 }
 
 Thread::~Thread()
 {
 	delete data_->dispatcher_.load(std::memory_order_relaxed);
-	delete data_;
 }
 
 /**
@@ -284,7 +286,7 @@ void Thread::startThread()
 	thread_local ThreadCleaner cleaner(this, &Thread::finishThread);
 
 	data_->tid_ = syscall(SYS_gettid);
-	currentThreadData = data_;
+	currentThreadData = data_.get();
 
 	run();
 }
@@ -516,7 +518,7 @@ pid_t Thread::currentId()
  */
 EventDispatcher *Thread::eventDispatcher()
 {
-	ASSERT(data_ == ThreadData::current());
+	ASSERT(data_.get() == ThreadData::current());
 
 	if (!data_->dispatcher_.load(std::memory_order_relaxed))
 		data_->dispatcher_.store(new EventDispatcherPoll(),
@@ -621,7 +623,7 @@ void Thread::removeMessages(Object *receiver)
  */
 void Thread::dispatchMessages(Message::Type type, Object *receiver)
 {
-	ASSERT(data_ == ThreadData::current());
+	ASSERT(data_.get() == ThreadData::current());
 
 	++data_->messages_.recursion_;
 
@@ -677,8 +679,8 @@ void Thread::dispatchMessages(Message::Type type, Object *receiver)
  */
 void Thread::moveObject(Object *object)
 {
-	ThreadData *currentData = object->thread_->data_;
-	ThreadData *targetData = data_;
+	ThreadData *currentData = object->thread_->data_.get();
+	ThreadData *targetData = data_.get();
 
 	MutexLocker lockerFrom(currentData->messages_.mutex_, std::defer_lock);
 	MutexLocker lockerTo(targetData->messages_.mutex_, std::defer_lock);