[libcamera-devel] [PATCH 1/2] cam: event_loop: Stop queuing calls when the event loop are exiting

[Niklas Söderlund]

Terminating the event loop with EventLoop::exit() does not grantee that
it will terminate. If the event loops 'call later' queue can be kept
non-empty by continuously queuing new calls using EventLoop::callLater()
either from a different thread or from callbacks in the loop itself
EventLoop::dispatchCalls() will never complete and the loop will run
forever.

Solve this by not accepting new callbacks once the event loop is
exiting.

Reported-by: Sebastian Fricke <sebastian.fricke at posteo.net>
Fixes: f49e93338b6309a6 ("cam: event_loop: Add deferred calls support")
Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 src/cam/event_loop.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/cam/event_loop.cpp b/src/cam/event_loop.cpp
index 94c5d1d362455f33..34a55da30c537ac7 100644
--- a/src/cam/event_loop.cpp
+++ b/src/cam/event_loop.cpp
@@ -62,7 +62,7 @@ void EventLoop::interrupt()
 
 void EventLoop::callLater(const std::function<void()> &func)
 {
-	{
+	if (!exit_.load(std::memory_order_acquire)) {
 		std::unique_lock<std::mutex> locker(lock_);
 		calls_.push_back(func);
 	}
-- 
2.30.0