test: fence: Add test for the Fence class

Add a test for the Fence class by testing a Fence failure case, and
by testing a successfully signalled fence capture cycle.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

2 files changed, 336 insertions, 0 deletions

diff --git a/test/fence.cpp b/test/fence.cpp
new file mode 100644
index 00000000..d2dfc9b6
--- /dev/null
+++ b/test/fence.cpp
@@ -0,0 +1,335 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * fence.cpp - Fence test
+ */
+
+#include <iostream>
+#include <memory>
+#include <sys/eventfd.h>
+#include <unistd.h>
+
+#include <libcamera/base/event_dispatcher.h>
+#include <libcamera/base/thread.h>
+#include <libcamera/base/timer.h>
+#include <libcamera/base/unique_fd.h>
+#include <libcamera/base/utils.h>
+
+#include <libcamera/fence.h>
+#include <libcamera/framebuffer_allocator.h>
+
+#include "camera_test.h"
+#include "test.h"
+
+using namespace std::chrono_literals;
+using namespace libcamera;
+using namespace std;
+
+class FenceTest : public CameraTest, public Test
+{
+public:
+	FenceTest();
+
+protected:
+	int init() override;
+	int run() override;
+
+private:
+	int validateExpiredRequest(Request *request);
+	int validateRequest(Request *request);
+	void requestComplete(Request *request);
+	void requestRequeue(Request *request);
+
+	void signalFence();
+
+	std::unique_ptr<Fence> fence_;
+	EventDispatcher *dispatcher_;
+	UniqueFD eventFd_;
+	UniqueFD eventFd2_;
+	Timer fenceTimer_;
+
+	std::vector<std::unique_ptr<Request>> requests_;
+	std::unique_ptr<CameraConfiguration> config_;
+	std::unique_ptr<FrameBufferAllocator> allocator_;
+
+	Stream *stream_;
+
+	bool expectedCompletionResult_ = true;
+
+	unsigned int completedRequest_;
+
+	unsigned int signalledRequestId_;
+	unsigned int expiredRequestId_;
+	unsigned int nbuffers_;
+
+	int efd2_;
+	int efd_;
+};
+
+FenceTest::FenceTest()
+	: CameraTest("platform/vimc.0 Sensor B")
+{
+}
+
+int FenceTest::init()
+{
+	/* Make sure the CameraTest constructor succeeded. */
+	if (status_ != TestPass)
+		return status_;
+
+	dispatcher_ = Thread::current()->eventDispatcher();
+
+	/*
+	 * Create two eventfds to model the fences. This is enough to support the
+	 * needs of libcamera which only needs to wait for read events through
+	 * poll(). Once native support for fences will be available in the
+	 * backend kernel APIs this will need to be replaced by a sw_sync fence,
+	 * but that requires debugfs.
+	 */
+	eventFd_ = UniqueFD(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK));
+	eventFd2_ = UniqueFD(eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK));
+	if (!eventFd_.isValid() || !eventFd2_.isValid()) {
+		cerr << "Unable to create eventfd" << endl;
+		return TestFail;
+	}
+
+	efd_ = eventFd_.get();
+	efd2_ = eventFd2_.get();
+
+	config_ = camera_->generateConfiguration({ StreamRole::Viewfinder });
+	if (!config_ || config_->size() != 1) {
+		cerr << "Failed to generate default configuration" << endl;
+		return TestFail;
+	}
+
+	if (camera_->acquire()) {
+		cerr << "Failed to acquire the camera" << endl;
+		return TestFail;
+	}
+
+	if (camera_->configure(config_.get())) {
+		cerr << "Failed to set default configuration" << endl;
+		return TestFail;
+	}
+
+	StreamConfiguration &cfg = config_->at(0);
+	stream_ = cfg.stream();
+
+	allocator_ = std::make_unique<FrameBufferAllocator>(camera_);
+	if (allocator_->allocate(stream_) < 0)
+		return TestFail;
+
+	nbuffers_ = allocator_->buffers(stream_).size();
+	if (nbuffers_ < 2) {
+		cerr << "Not enough buffers available" << endl;
+		return TestFail;
+	}
+
+	signalledRequestId_ = nbuffers_ - 2;
+	expiredRequestId_ = nbuffers_ - 1;
+
+	return TestPass;
+}
+
+int FenceTest::validateExpiredRequest(Request *request)
+{
+	/* The last request is expected to fail. */
+	if (request->status() != Request::RequestCancelled) {
+		cerr << "The last request should have failed: " << endl;
+		return TestFail;
+	}
+
+	FrameBuffer *buffer = request->buffers().begin()->second;
+	std::unique_ptr<Fence> fence = buffer->releaseFence();
+	if (!fence) {
+		cerr << "The expired fence should be present" << endl;
+		return TestFail;
+	}
+
+	if (!fence->isValid()) {
+		cerr << "The expired fence should be valid" << endl;
+		return TestFail;
+	}
+
+	UniqueFD fd = fence->release();
+	if (fd.get() != efd_) {
+		cerr << "The expired fence file descriptor should not change" << endl;
+		return TestFail;
+	}
+
+	return TestPass;
+}
+
+int FenceTest::validateRequest(Request *request)
+{
+	uint64_t cookie = request->cookie();
+
+	/* All requests but the last are expected to succeed. */
+	if (request->status() != Request::RequestComplete) {
+		cerr << "Unexpected request failure: " << cookie << endl;
+		return TestFail;
+	}
+
+	/* A successfully completed request should have the Fence closed. */
+	const Request::BufferMap &buffers = request->buffers();
+	FrameBuffer *buffer = buffers.begin()->second;
+
+	std::unique_ptr<Fence> bufferFence = buffer->releaseFence();
+	if (bufferFence) {
+		cerr << "Unexpected valid fence in completed request" << endl;
+		return TestFail;
+	}
+
+	return TestPass;
+}
+
+void FenceTest::requestRequeue(Request *request)
+{
+	const Request::BufferMap &buffers = request->buffers();
+	const Stream *stream = buffers.begin()->first;
+	FrameBuffer *buffer = buffers.begin()->second;
+	uint64_t cookie = request->cookie();
+
+	request->reuse();
+
+	if (cookie == signalledRequestId_) {
+		/*
+		 * The second time this request is queued add a fence to it.
+		 *
+		 * The main loop signals it by using a timer to write to the
+		 * efd2_ file descriptor before the fence expires.
+		 */
+		std::unique_ptr<Fence> fence =
+			std::make_unique<Fence>(std::move(eventFd2_));
+		request->addBuffer(stream, buffer, std::move(fence));
+	} else {
+		/* All the other requests continue to operate without fences. */
+		request->addBuffer(stream, buffer);
+	}
+
+	camera_->queueRequest(request);
+}
+
+void FenceTest::requestComplete(Request *request)
+{
+	uint64_t cookie = request->cookie();
+	completedRequest_ = cookie;
+
+	/*
+	 * The last request is expected to fail as its fence has not been
+	 * signaled.
+	 *
+	 * Validate the fence status but do not re-queue it.
+	 */
+	if (cookie == expiredRequestId_) {
+		if (validateExpiredRequest(request) != TestPass)
+			expectedCompletionResult_ = false;
+
+		dispatcher_->interrupt();
+		return;
+	}
+
+	/* Validate all requests but the last. */
+	if (validateRequest(request) != TestPass) {
+		expectedCompletionResult_ = false;
+
+		dispatcher_->interrupt();
+		return;
+	}
+
+	requestRequeue(request);
+
+	/*
+	 * Interrupt the dispatcher to return control to the main loop and
+	 * activate the fenceTimer.
+	 */
+	dispatcher_->interrupt();
+}
+
+/* Callback to signal a fence waiting on the eventfd file descriptor. */
+void FenceTest::signalFence()
+{
+	uint64_t value = 1;
+	write(efd2_, &value, sizeof(value));
+	dispatcher_->processEvents();
+}
+
+int FenceTest::run()
+{
+	for (const auto &[i, buffer] : utils::enumerate(allocator_->buffers(stream_))) {
+		std::unique_ptr<Request> request = camera_->createRequest(i);
+		if (!request) {
+			cerr << "Failed to create request" << endl;
+			return TestFail;
+		}
+
+		int ret;
+		if (i == expiredRequestId_) {
+			/* This request will have a fence, and it will expire. */
+			fence_ = std::make_unique<Fence>(std::move(eventFd_));
+			if (!fence_->isValid()) {
+				cerr << "Fence should be valid" << endl;
+				return TestFail;
+			}
+
+			ret = request->addBuffer(stream_, buffer.get(), std::move(fence_));
+		} else {
+			/* All other requests will have no Fence. */
+			ret = request->addBuffer(stream_, buffer.get());
+		}
+
+		if (ret) {
+			cerr << "Failed to associate buffer with request" << endl;
+			return TestFail;
+		}
+
+		requests_.push_back(std::move(request));
+	}
+
+	camera_->requestCompleted.connect(this, &FenceTest::requestComplete);
+
+	if (camera_->start()) {
+		cerr << "Failed to start camera" << endl;
+		return TestFail;
+	}
+
+	for (std::unique_ptr<Request> &request : requests_) {
+		if (camera_->queueRequest(request.get())) {
+			cerr << "Failed to queue request" << endl;
+			return TestFail;
+		}
+	}
+
+	expectedCompletionResult_ = true;
+
+	/* This timer serves to signal fences associated with "signalledRequestId_" */
+	Timer fenceTimer;
+	fenceTimer.timeout.connect(this, &FenceTest::signalFence);
+
+	/* Loop for one second. */
+	Timer timer;
+	timer.start(1000);
+	while (timer.isRunning() && expectedCompletionResult_) {
+		if (completedRequest_ == signalledRequestId_)
+			/*
+			 * signalledRequestId_ has just completed and it has
+			 * been re-queued with a fence. Start the timer to
+			 * signal the fence in 10 msec.
+			 */
+			fenceTimer.start(10);
+
+		dispatcher_->processEvents();
+	}
+
+	camera_->requestCompleted.disconnect();
+
+	if (camera_->stop()) {
+		cerr << "Failed to stop camera" << endl;
+		return TestFail;
+	}
+
+	return expectedCompletionResult_ ? TestPass : TestFail;
+}
+
+TEST_REGISTER(FenceTest)
diff --git a/test/meson.build b/test/meson.build
index daaa3862..2c9487e2 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -39,6 +39,7 @@ internal_tests = [
     ['event',                           'event.cpp'],
     ['event-dispatcher',                'event-dispatcher.cpp'],
     ['event-thread',                    'event-thread.cpp'],
+    ['fence',                           'fence.cpp'],
     ['file',                            'file.cpp'],
     ['flags',                           'flags.cpp'],
     ['hotplug-cameras',                 'hotplug-cameras.cpp'],