[PATCH v2 09/12] test: timer-thread: Move timer start from wrong thread to separate test

[Laurent Pinchart]

Starting a timer from the wrong thread is expected to fail, and we test
this in the timer-thread unit test. This is however not something that a
caller is allowed to do, and libcamera will get assertion failures to
catch this invalid usage. The unit test will then fail.

To prepare for this, split the unit test in two, with a test that is
expected by meson to succeed, and one that is expected to fail. The
assertion will then cause an expected failure, making the test suite
succeed.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
Changes since v1:

- Improve comment explaining why the test is expected to fail
---
 test/meson.build      |   9 ++--
 test/timer-fail.cpp   | 103 ++++++++++++++++++++++++++++++++++++++++++
 test/timer-thread.cpp |  22 ---------
 3 files changed, 109 insertions(+), 25 deletions(-)
 create mode 100644 test/timer-fail.cpp

diff --git a/test/meson.build b/test/meson.build
index 189e1428485a..8b6057d4e800 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -69,6 +69,7 @@ internal_tests = [
     {'name': 'signal-threads', 'sources': ['signal-threads.cpp']},
     {'name': 'threads', 'sources': 'threads.cpp', 'dependencies': [libthreads]},
     {'name': 'timer', 'sources': ['timer.cpp']},
+    {'name': 'timer-fail', 'sources': ['timer-fail.cpp'], 'should_fail': true},
     {'name': 'timer-thread', 'sources': ['timer-thread.cpp']},
     {'name': 'unique-fd', 'sources': ['unique-fd.cpp']},
     {'name': 'utils', 'sources': ['utils.cpp']},
@@ -91,7 +92,7 @@ foreach test : public_tests
                      link_with : test_libraries,
                      include_directories : test_includes_public)
 
-    test(test['name'], exe)
+    test(test['name'], exe, should_fail : test.get('should_fail', false))
 endforeach
 
 foreach test : internal_tests
@@ -105,7 +106,7 @@ foreach test : internal_tests
                      link_with : test_libraries,
                      include_directories : test_includes_internal)
 
-    test(test['name'], exe)
+    test(test['name'], exe, should_fail : test.get('should_fail', false))
 endforeach
 
 foreach test : internal_non_parallel_tests
@@ -119,5 +120,7 @@ foreach test : internal_non_parallel_tests
                      link_with : test_libraries,
                      include_directories : test_includes_internal)
 
-    test(test['name'], exe, is_parallel : false)
+    test(test['name'], exe,
+         is_parallel : false,
+         should_fail : test.get('should_fail', false))
 endforeach
diff --git a/test/timer-fail.cpp b/test/timer-fail.cpp
new file mode 100644
index 000000000000..2c622ca3410d
--- /dev/null
+++ b/test/timer-fail.cpp
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2024, Ideas on Board Oy
+ *
+ * timer-fail.cpp - Threaded timer failure test
+ */
+
+#include <chrono>
+#include <iostream>
+
+#include <libcamera/base/event_dispatcher.h>
+#include <libcamera/base/object.h>
+#include <libcamera/base/thread.h>
+#include <libcamera/base/timer.h>
+
+#include "test.h"
+
+using namespace libcamera;
+using namespace std;
+using namespace std::chrono_literals;
+
+class TimeoutHandler : public Object
+{
+public:
+	TimeoutHandler()
+		: timer_(this), timeout_(false)
+	{
+		timer_.timeout.connect(this, &TimeoutHandler::timeoutHandler);
+	}
+
+	void start()
+	{
+		timer_.start(100ms);
+	}
+
+	bool timeout() const
+	{
+		return timeout_;
+	}
+
+private:
+	void timeoutHandler()
+	{
+		timeout_ = true;
+	}
+
+	Timer timer_;
+	bool timeout_;
+};
+
+class TimerFailTest : public Test
+{
+protected:
+	int init()
+	{
+		thread_.start();
+		timeout_.moveToThread(&thread_);
+
+		return TestPass;
+	}
+
+	int run()
+	{
+		/*
+		 * Test that the forbidden operation of starting the timer from
+		 * another thread results in a failure. We need to interrupt the
+		 * event dispatcher to make sure we don't succeed simply because
+		 * the event dispatcher hasn't noticed the timer restart.
+		 */
+		timeout_.start();
+		thread_.eventDispatcher()->interrupt();
+
+		this_thread::sleep_for(chrono::milliseconds(200));
+
+		/*
+		 * The wrong start() call should result in an assertion in debug
+		 * builds, and a timeout in release builds. The test is
+		 * therefore marked in meson.build as expected to fail. We need
+		 * to return TestPass in the unexpected (usually known as
+		 * "fail") case, and TestFail otherwise.
+		 */
+		if (timeout_.timeout()) {
+			cout << "Timer start from wrong thread succeeded unexpectedly"
+			     << endl;
+			return TestPass;
+		}
+
+		return TestFail;
+	}
+
+	void cleanup()
+	{
+		/* Must stop thread before destroying timeout. */
+		thread_.exit(0);
+		thread_.wait();
+	}
+
+private:
+	TimeoutHandler timeout_;
+	Thread thread_;
+};
+
+TEST_REGISTER(TimerFailTest)
diff --git a/test/timer-thread.cpp b/test/timer-thread.cpp
index 0bcd0d8ce194..4caf4e33b2ba 100644
--- a/test/timer-thread.cpp
+++ b/test/timer-thread.cpp
@@ -29,12 +29,6 @@ public:
 		timer_.start(100ms);
 	}
 
-	void restart()
-	{
-		timeout_ = false;
-		timer_.start(100ms);
-	}
-
 	bool timeout() const
 	{
 		return timeout_;
@@ -74,22 +68,6 @@ protected:
 			return TestFail;
 		}
 
-		/*
-		 * Test that starting the timer from another thread fails. We
-		 * need to interrupt the event dispatcher to make sure we don't
-		 * succeed simply because the event dispatcher hasn't noticed
-		 * the timer restart.
-		 */
-		timeout_.restart();
-		thread_.eventDispatcher()->interrupt();
-
-		this_thread::sleep_for(chrono::milliseconds(200));
-
-		if (timeout_.timeout()) {
-			cout << "Timer restart test failed" << endl;
-			return TestFail;
-		}
-
 		return TestPass;
 	}
 
-- 
Regards,

Laurent Pinchart