tests: Test event dispatcher interruption by signal

Add a test to verify that the event dispatcher correctly restarts event
processing when interrupted by a signal. The test currently fails as
this feature isn't implemented.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

test/event-dispatcher.cpp

@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * event-dispatcher.cpp - Event dispatcher test
+ */
+
+#include <iostream>
+#include <signal.h>
+#include <sys/time.h>
+
+#include <libcamera/camera_manager.h>
+#include <libcamera/event_dispatcher.h>
+#include <libcamera/timer.h>
+
+#include "test.h"
+
+using namespace std;
+using namespace libcamera;
+
+class EventDispatcherTest : public Test
+{
+protected:
+	static void sigAlarmHandler(int)
+	{
+		cout << "SIGALARM received" << endl;
+	}
+
+	int init()
+	{
+		struct sigaction sa = {};
+		sa.sa_handler = &sigAlarmHandler;
+		sigaction(SIGALRM, &sa, nullptr);
+
+		return 0;
+	}
+
+	int run()
+	{
+		EventDispatcher *dispatcher = CameraManager::instance()->eventDispatcher();
+		Timer timer;
+
+		/* Event processing interruption by signal. */
+		struct timespec start;
+		clock_gettime(CLOCK_MONOTONIC, &start);
+
+		timer.start(1000);
+
+		struct itimerval itimer = {};
+		itimer.it_value.tv_usec = 500000;
+		setitimer(ITIMER_REAL, &itimer, nullptr);
+
+		dispatcher->processEvents();
+
+		struct timespec stop;
+		clock_gettime(CLOCK_MONOTONIC, &stop);
+		int duration = (stop.tv_sec - start.tv_sec) * 1000;
+		duration += (stop.tv_nsec - start.tv_nsec) / 1000000;
+
+		if (abs(duration - 1000) > 50) {
+			cout << "Event processing restart test failed" << endl;
+			return TestFail;
+		}
+
+		return TestPass;
+	}
+
+	void cleanup()
+	{
+	}
+};
+
+TEST_REGISTER(EventDispatcherTest)

test/meson.build

@@ -5,10 +5,11 @@ subdir('pipeline')
 subdir('v4l2_device')
 
 public_tests = [
-    ['event',           'event.cpp'],
+    ['event',                           'event.cpp'],
-    ['list-cameras',    'list-cameras.cpp'],
+    ['event-dispatcher',                'event-dispatcher.cpp'],
-    ['signal',          'signal.cpp'],
+    ['list-cameras',                    'list-cameras.cpp'],
-    ['timer',           'timer.cpp'],
+    ['signal',                          'signal.cpp'],
+    ['timer',                           'timer.cpp'],
 ]
 
 internal_tests = [