[libcamera-devel] [PATCH v3 1/3] libcamera: thread: Support selective message dispatch to thread

[Laurent Pinchart]

Hi Umang,

Thank you for the patch.

On Fri, Jul 31, 2020 at 01:39:53PM +0000, Umang Jain wrote:
> Extend the current dispatchMessages() to support dispatching of
> selective messsages according to the Message::Type passed in
> the function argument. dispatchMessages() can now be called
> explicitly to force deliver selected type's message to the
> thread for processing (typically when event loop is not
> running).
> 
> Signed-off-by: Umang Jain <email at uajain.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

> ---
>  include/libcamera/internal/thread.h |  3 ++-
>  src/libcamera/thread.cpp            | 30 ++++++++++++++++++++---------
>  2 files changed, 23 insertions(+), 10 deletions(-)
> 
> diff --git a/include/libcamera/internal/thread.h b/include/libcamera/internal/thread.h
> index 7b59e58..f6367a8 100644
> --- a/include/libcamera/internal/thread.h
> +++ b/include/libcamera/internal/thread.h
> @@ -14,6 +14,7 @@
>  
>  #include <libcamera/signal.h>
>  
> +#include "libcamera/internal/message.h"
>  #include "libcamera/internal/utils.h"
>  
>  namespace libcamera {
> @@ -47,7 +48,7 @@ public:
>  	EventDispatcher *eventDispatcher();
>  	void setEventDispatcher(std::unique_ptr<EventDispatcher> dispatcher);
>  
> -	void dispatchMessages();
> +	void dispatchMessages(Message::Type type = Message::Type::None);
>  
>  protected:
>  	int exec();
> diff --git a/src/libcamera/thread.cpp b/src/libcamera/thread.cpp
> index d1750d7..7e318d9 100644
> --- a/src/libcamera/thread.cpp
> +++ b/src/libcamera/thread.cpp
> @@ -552,25 +552,37 @@ void Thread::removeMessages(Object *receiver)
>  }
>  
>  /**
> - * \brief Dispatch all posted messages for this thread
> + * \brief Dispatch posted messages for this thread
> + * \param[in] type The message type
> + *
> + * This function immediately dispatches all the messages previously posted for
> + * this thread with postMessage() that match the message \a type. If the \a type
> + * is Message::Type::None, all messages are dispatched.
>   */
> -void Thread::dispatchMessages()
> +void Thread::dispatchMessages(Message::Type type)
>  {
>  	MutexLocker locker(data_->messages_.mutex_);
>  
> -	while (!data_->messages_.list_.empty()) {
> -		std::unique_ptr<Message> msg = std::move(data_->messages_.list_.front());
> -		data_->messages_.list_.pop_front();
> -		if (!msg)
> +	std::list<std::unique_ptr<Message>> &messages = data_->messages_.list_;
> +
> +	for (auto iter = messages.begin(); iter != messages.end(); ) {
> +		std::unique_ptr<Message> &msg = *iter;
> +
> +		if (!msg || (type != Message::Type::None && msg->type() != type)) {
> +			++iter;
>  			continue;
> +		}
>  
> -		Object *receiver = msg->receiver_;
> -		ASSERT(data_ == receiver->thread()->data_);
> +		std::unique_ptr<Message> message = std::move(msg);
> +		iter = data_->messages_.list_.erase(iter);
>  
> +		Object *receiver = message->receiver_;
> +		ASSERT(data_ == receiver->thread()->data_);
>  		receiver->pendingMessages_--;
>  
>  		locker.unlock();
> -		receiver->message(msg.get());
> +		receiver->message(message.get());
> +		message.reset();
>  		locker.lock();
>  	}
>  }

-- 
Regards,

Laurent Pinchart