test: Add Thread test cases

The Thread test case verifies that

- a Thread instance is created for the main thread
- a new Thread can be created, started, and stopped

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

test/meson.build

@@ -21,6 +21,7 @@ public_tests = [
 
 internal_tests = [
     ['camera-sensor',                   'camera-sensor.cpp'],
+    ['threads',                         'threads.cpp'],
 ]
 
 foreach t : public_tests

test/threads.cpp

@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * threads.cpp - Threads test
+ */
+
+#include <chrono>
+#include <iostream>
+#include <thread>
+
+#include "thread.h"
+#include "test.h"
+
+using namespace std;
+using namespace libcamera;
+
+class InstrumentedThread : public Thread
+{
+public:
+	InstrumentedThread(unsigned int iterations)
+		: iterations_(iterations)
+	{
+	}
+
+protected:
+	void run()
+	{
+		for (unsigned int i = 0; i < iterations_; ++i) {
+			this_thread::sleep_for(chrono::milliseconds(50));
+		}
+	}
+
+private:
+	unsigned int iterations_;
+};
+
+class ThreadTest : public Test
+{
+protected:
+	int init()
+	{
+		return 0;
+	}
+
+	int run()
+	{
+		/* Test Thread() retrieval for the main thread. */
+		Thread *thread = Thread::current();
+		if (!thread) {
+			cout << "Thread::current() failed to main thread"
+			     << endl;
+			return TestFail;
+		}
+
+		if (!thread->isRunning()) {
+			cout << "Main thread is not running" << endl;
+			return TestFail;
+		}
+
+		/* Test starting the main thread, the test shall not crash. */
+		thread->start();
+
+		/* Test the running state of a custom thread. */
+		thread = new Thread();
+		thread->start();
+
+		if (!thread->isRunning()) {
+			cout << "Thread is not running after being started"
+			     << endl;
+			return TestFail;
+		}
+
+		thread->exit(0);
+		thread->wait();
+
+		if (thread->isRunning()) {
+			cout << "Thread is still running after finishing"
+			     << endl;
+			return TestFail;
+		}
+
+		delete thread;
+
+		return TestPass;
+	}
+
+	void cleanup()
+	{
+	}
+};
+
+TEST_REGISTER(ThreadTest)