[libcamera-devel] [PATCH v5 2/2] cam: event_loop: Add timed events to event loop

[Eric Curtin]

If you add an event with EventLoop::Default, that event will be executed
every 10ms or at a rate of 100fps. Used to handle resize of windows and
quit events in SDL.

Signed-off-by: Eric Curtin <ecurtin at redhat.com>
---
 src/cam/event_loop.cpp | 10 +++++++++-
 src/cam/event_loop.h   |  1 +
 src/cam/sdl_sink.cpp   |  2 +-
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/cam/event_loop.cpp b/src/cam/event_loop.cpp
index e25784c0..7a5ed4da 100644
--- a/src/cam/event_loop.cpp
+++ b/src/cam/event_loop.cpp
@@ -75,7 +75,15 @@ void EventLoop::addEvent(int fd, EventType type,
 		return;
 	}
 
-	int ret = event_add(event->event_, nullptr);
+	struct timeval *tp = nullptr;
+	struct timeval tv;
+	if (events == EV_PERSIST) { /* EventType = Default */
+		tp = &tv;
+		tv.tv_sec = 0;
+		tv.tv_usec = 10000; /* every 10 ms */
+	}
+
+	int ret = event_add(event->event_, tp);
 	if (ret < 0) {
 		std::cerr << "Failed to add event for fd " << fd << std::endl;
 		return;
diff --git a/src/cam/event_loop.h b/src/cam/event_loop.h
index a4613eb2..8fd9bd20 100644
--- a/src/cam/event_loop.h
+++ b/src/cam/event_loop.h
@@ -20,6 +20,7 @@ class EventLoop
 {
 public:
 	enum EventType {
+		Default = 0, /* the event can be triggered only by a timeout or by manual activation */
 		Read = 1,
 		Write = 2,
 	};
diff --git a/src/cam/sdl_sink.cpp b/src/cam/sdl_sink.cpp
index 28e59cbb..97a550b5 100644
--- a/src/cam/sdl_sink.cpp
+++ b/src/cam/sdl_sink.cpp
@@ -117,7 +117,7 @@ int SDLSink::start()
 		return -EINVAL;
 	}
 
-	EventLoop::instance()->addEvent(-1, EventLoop::Read, std::bind(&SDLSink::processSDLEvents, this));
+	EventLoop::instance()->addEvent(-1, EventLoop::Default, std::bind(&SDLSink::processSDLEvents, this));
 
 	return 0;
 }
-- 
2.35.1