libcamera: thread: Support dispatching messages to main thread

Threads contain message queues and dispatch queued messages in their
event loop, in Thread::exec(). This mechanism prevents the main thread
from dispatching messages as it doesn't run Thread::exec().

Fix this by moving message dispatching from Thread::exec() to
EventDispatcher::processEvents().

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/libcamera/event_dispatcher_poll.cpp b/src/libcamera/event_dispatcher_poll.cpp
index 4f15f3e3..281f37bd 100644
--- a/src/libcamera/event_dispatcher_poll.cpp
+++ b/src/libcamera/event_dispatcher_poll.cpp
@@ -19,6 +19,7 @@
 #include <libcamera/timer.h>
 
 #include "log.h"
+#include "thread.h"
 
 /**
  * \file event_dispatcher_poll.h
@@ -143,6 +144,8 @@ void EventDispatcherPoll::processEvents()
 {
 	int ret;
 
+	Thread::current()->dispatchMessages();
+
 	/* Create the pollfd array. */
 	std::vector<struct pollfd> pollfds;
 	pollfds.reserve(notifiers_.size() + 1);