1 files changed, 76 insertions, 1 deletions
diff --git a/src/libcamera/object.cpp b/src/libcamera/object.cpp
index a504ca2c..fa228483 100644
--- a/src/libcamera/object.cpp
+++ b/src/libcamera/object.cpp
@@ -9,6 +9,9 @@
 
 #include <libcamera/signal.h>
 
+#include "log.h"
+#include "thread.h"
+
 /**
  * \file object.h
  * \brief Base object to support automatic signal disconnection
@@ -24,13 +27,85 @@ namespace libcamera {
  * slots. By inheriting from Object, an object is automatically disconnected
  * from all connected signals when it gets destroyed.
  *
- * \sa Signal
+ * Object instances are bound to the thread in which they're created. When a
+ * message is posted to an object, its handler will run in the object's thread.
+ * This allows implementing easy message passing between threads by inheriting
+ * from the Object class.
+ *
+ * \sa Message, Signal, Thread
  */
 
+Object::Object()
+	: pendingMessages_(0)
+{
+	thread_ = Thread::current();
+}
+
 Object::~Object()
 {
 	for (SignalBase *signal : signals_)
 		signal->disconnect(this);
+
+	if (pendingMessages_)
+		thread()->removeMessages(this);
+}
+
+/**
+ * \brief Post a message to the object's thread
+ * \param[in] msg The message
+ *
+ * This method posts the message \a msg to the message queue of the object's
+ * thread, to be delivered to the object through the message() method in the
+ * context of its thread. Message ownership is passed to the thread, and the
+ * message will be deleted after being delivered.
+ *
+ * Messages are delivered through the thread's event loop. If the thread is not
+ * running its event loop the message will not be delivered until the event
+ * loop gets started.
+ */
+void Object::postMessage(std::unique_ptr<Message> msg)
+{
+	thread()->postMessage(std::move(msg), this);
+}
+
+/**
+ * \brief Message handler for the object
+ * \param[in] msg The message
+ *
+ * This virtual method receives messages for the object. It is called in the
+ * context of the object's thread, and can be overridden to process custom
+ * messages. The parent Object::message() method shall be called for any
+ * message not handled by the override method.
+ *
+ * The message \a msg is valid only for the duration of the call, no reference
+ * to it shall be kept after this method returns.
+ */
+void Object::message(Message *msg)
+{
+}
+
+/**
+ * \fn Object::thread()
+ * \brief Retrieve the thread the object is bound to
+ * \return The thread the object is bound to
+ */
+
+/**
+ * \brief Move the object to a different thread
+ * \param[in] thread The target thread
+ *
+ * This method moves the object from the current thread to the new \a thread.
+ * It shall be called from the thread in which the object currently lives,
+ * otherwise the behaviour is undefined.
+ */
+void Object::moveToThread(Thread *thread)
+{
+	ASSERT(Thread::current() == thread_);
+
+	if (thread_ == thread)
+		return;
+
+	thread->moveObject(this);
 }
 
 void Object::connect(SignalBase *signal)