[libcamera-devel] [PATCH 6/6] test: Add test case for signal delivery across threads

[Niklas Söderlund]

Hi Laurent,

Thanks for your test.

On 2019-07-10 22:17:08 +0300, Laurent Pinchart wrote:
> The test case creates a receiver inheriting from Object, connects a
> signal to one of its slot, moves the receiver to a different thread,
> emits the signal and verifies that it gets delivered in the correct
> thread with the expected value.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  test/meson.build        |   1 +
>  test/signal-threads.cpp | 125 ++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 126 insertions(+)
>  create mode 100644 test/signal-threads.cpp
> 
> diff --git a/test/meson.build b/test/meson.build
> index 1f87319aeb65..60ce9601cc55 100644
> --- a/test/meson.build
> +++ b/test/meson.build
> @@ -22,6 +22,7 @@ public_tests = [
>  internal_tests = [
>      ['camera-sensor',                   'camera-sensor.cpp'],
>      ['message',                         'message.cpp'],
> +    ['signal-threads',                  'signal-threads.cpp'],
>      ['threads',                         'threads.cpp'],
>  ]
>  
> diff --git a/test/signal-threads.cpp b/test/signal-threads.cpp
> new file mode 100644
> index 000000000000..c21f32ae0c20
> --- /dev/null
> +++ b/test/signal-threads.cpp
> @@ -0,0 +1,125 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2019, Google Inc.
> + *
> + * signal-threads.cpp - Cross-thread signal delivery test
> + */
> +
> +#include <chrono>
> +#include <iostream>
> +#include <thread>
> +
> +#include "message.h"
> +#include "thread.h"
> +#include "test.h"
> +#include "utils.h"
> +
> +using namespace std;
> +using namespace libcamera;
> +
> +class SignalReceiver : public Object
> +{
> +public:
> +	enum Status {
> +		NoSignal,
> +		InvalidThread,
> +		SignalReceived,
> +	};
> +
> +	SignalReceiver()
> +		: status_(NoSignal)
> +	{
> +	}
> +
> +	Status status() const { return status_; }
> +	int value() const { return value_; }
> +	void reset()
> +	{
> +		status_ = NoSignal;
> +		value_ = 0;
> +	}
> +
> +	void slot(int value)
> +	{
> +		if (Thread::current() != thread())
> +			status_ = InvalidThread;
> +		else
> +			status_ = SignalReceived;
> +
> +		value_ = value;
> +	}
> +
> +private:
> +	Status status_;
> +	int value_;
> +};
> +
> +class SignalThreadsTest : public Test
> +{
> +protected:
> +	int run()
> +	{
> +		SignalReceiver receiver;
> +		signal_.connect(&receiver, &SignalReceiver::slot);
> +
> +		/* Test that a signal is received in the main thread. */
> +		signal_.emit(42);
> +
> +		switch (receiver.status()) {
> +		case SignalReceiver::NoSignal:
> +			cout << "No signal received for direct connection" << endl;
> +			return TestFail;
> +		case SignalReceiver::InvalidThread:
> +			cout << "Signal received in incorrect thread "
> +				"for direct connection" << endl;
> +			return TestFail;
> +		default:
> +			break;
> +		}

It's verified in other Signal tests that the argument(s) are delivered 
but for the sake of us with OCD you might consider adding a 
receiver.value() != 42 check here ;-)

With this fixed,

Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>

> +
> +		/*
> +		 * Move the object to a thread and verify that the signal is
> +		 * correctly delivered, with the correct data.
> +		 */
> +		receiver.reset();
> +		receiver.moveToThread(&thread_);
> +
> +		thread_.start();
> +
> +		signal_.emit(42);
> +
> +		this_thread::sleep_for(chrono::milliseconds(100));
> +
> +		switch (receiver.status()) {
> +		case SignalReceiver::NoSignal:
> +			cout << "No signal received for message connection" << endl;
> +			return TestFail;
> +		case SignalReceiver::InvalidThread:
> +			cout << "Signal received in incorrect thread "
> +				"for message connection" << endl;
> +			return TestFail;
> +		default:
> +			break;
> +		}
> +
> +		if (receiver.value() != 42) {
> +			cout << "Signal received with incorrect value" << endl;
> +			return TestFail;
> +		}
> +
> +		return TestPass;
> +	}
> +
> +	void cleanup()
> +	{
> +		thread_.exit(0);
> +		thread_.wait();
> +	}
> +
> +private:
> +	Thread thread_;
> +
> +	Signal<int> signal_;
> +};
> +
> +TEST_REGISTER(SignalThreadsTest)
> -- 
> Regards,
> 
> Laurent Pinchart
> 
> _______________________________________________
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> libcamera-devel at lists.libcamera.org
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-- 
Regards,
Niklas Söderlund