test: camera: Camera reconfiguration and fd-leak test

Development and usage of isolated IPA's has identified bugs in the
transmission of the file descriptors between the pipeline handler and
the IPA through.

Add tests to identify these bugs and prevent regressions.

This tests basically checks for two things:
- Camera reconfigurations without stopping CameraManager
- Fd leaks across IPA IPC boundary [1]

Currently, it uses vimc, but can be easily changed to using another
platform (for e.g. IPU3) by changing kCamId_ and kIpaProxyName_.

The test performs kNumOfReconfigures_ (currently set to 10)
reconfigurations of the camera. Each reconfiguration runs
start(), capture(100ms), stop() of the camera. Hence, the test
runs approximately for 1 second.

For checking the fd leaks, the test monitors the /proc/$PROXY_PID/fd
directory for open fds. It compares the number of open fds after each
run to the number of open fds before the first run. If those two are
found to be mis-matched, the test shall report failure.

The test validates IPA IPC code paths which are used when the IPA is run
in isolated mode. The CameraTest is constructed with the isolate flag
set to enforce this.

[1] https://bugs.libcamera.org/show_bug.cgi?id=63

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

2 files changed, 263 insertions, 0 deletions

diff --git a/test/camera/camera_reconfigure.cpp b/test/camera/camera_reconfigure.cpp
new file mode 100644
index 00000000..5adef16e
--- /dev/null
+++ b/test/camera/camera_reconfigure.cpp
@@ -0,0 +1,262 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * Test:
+ * - Multiple reconfigurations of the Camera without stopping the CameraManager
+ * - Validate there are no file descriptor leaks when using IPC
+ */
+
+#include <dirent.h>
+#include <fstream>
+#include <iostream>
+
+#include <libcamera/base/event_dispatcher.h>
+#include <libcamera/base/file.h>
+#include <libcamera/base/thread.h>
+#include <libcamera/base/timer.h>
+
+#include <libcamera/framebuffer_allocator.h>
+
+#include "camera_test.h"
+#include "test.h"
+
+using namespace std;
+
+namespace {
+
+class CameraReconfigure : public CameraTest, public Test
+{
+public:
+	/* Initialize CameraTest with isolated IPA */
+	CameraReconfigure()
+		: CameraTest(kCamId_, true)
+	{
+	}
+
+private:
+	static constexpr const char *kCamId_ = "platform/vimc.0 Sensor B";
+	static constexpr const char *kIpaProxyName_ = "vimc_ipa_proxy";
+	static constexpr unsigned int kNumOfReconfigures_ = 10;
+
+	void requestComplete(Request *request)
+	{
+		if (request->status() != Request::RequestComplete)
+			return;
+
+		const Request::BufferMap &buffers = request->buffers();
+
+		const Stream *stream = buffers.begin()->first;
+		FrameBuffer *buffer = buffers.begin()->second;
+
+		/* Reuse the request and re-queue it with the same buffers. */
+		request->reuse();
+		request->addBuffer(stream, buffer);
+		camera_->queueRequest(request);
+	}
+
+	int startAndStop()
+	{
+		StreamConfiguration &cfg = config_->at(0);
+
+		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;
+		}
+
+		Stream *stream = cfg.stream();
+
+		/*
+		 * The configuration is consistent so we can re-use the
+		 * same buffer allocation for each run.
+		 */
+		if (!allocated_) {
+			int ret = allocator_->allocate(stream);
+			if (ret < 0) {
+				cerr << "Failed to allocate buffers" << endl;
+				return TestFail;
+			}
+			allocated_ = true;
+		}
+
+		for (const unique_ptr<FrameBuffer> &buffer : allocator_->buffers(stream)) {
+			unique_ptr<Request> request = camera_->createRequest();
+			if (!request) {
+				cerr << "Failed to create request" << endl;
+				return TestFail;
+			}
+
+			if (request->addBuffer(stream, buffer.get())) {
+				cerr << "Failed to associate buffer with request" << endl;
+				return TestFail;
+			}
+
+			requests_.push_back(move(request));
+		}
+
+		camera_->requestCompleted.connect(this, &CameraReconfigure::requestComplete);
+
+		if (camera_->start()) {
+			cerr << "Failed to start camera" << endl;
+			return TestFail;
+		}
+
+		for (unique_ptr<Request> &request : requests_) {
+			if (camera_->queueRequest(request.get())) {
+				cerr << "Failed to queue request" << endl;
+				return TestFail;
+			}
+		}
+
+		EventDispatcher *dispatcher = Thread::current()->eventDispatcher();
+
+		Timer timer;
+		timer.start(100);
+		while (timer.isRunning())
+			dispatcher->processEvents();
+
+		if (camera_->stop()) {
+			cerr << "Failed to stop camera" << endl;
+			return TestFail;
+		}
+
+		if (camera_->release()) {
+			cerr << "Failed to release camera" << endl;
+			return TestFail;
+		}
+
+		camera_->requestCompleted.disconnect(this, &CameraReconfigure::requestComplete);
+
+		requests_.clear();
+
+		return 0;
+	}
+
+	int fdsOpen(pid_t pid)
+	{
+		string proxyFdPath = "/proc/" + to_string(pid) + "/fd";
+		DIR *dir;
+		struct dirent *ptr;
+		unsigned int openFds = 0;
+
+		dir = opendir(proxyFdPath.c_str());
+		if (dir == nullptr) {
+			int err = errno;
+			cerr << "Error opening " << proxyFdPath << ": "
+			     << strerror(-err) << endl;
+			return 0;
+		}
+
+		while ((ptr = readdir(dir)) != nullptr) {
+			if ((strcmp(ptr->d_name, ".") == 0) ||
+			    (strcmp(ptr->d_name, "..") == 0))
+				continue;
+
+			openFds++;
+		}
+		closedir(dir);
+
+		return openFds;
+	}
+
+	pid_t findProxyPid()
+	{
+		string proxyPid;
+		string proxyName(kIpaProxyName_);
+		DIR *dir;
+		struct dirent *ptr;
+
+		dir = opendir("/proc");
+		while ((ptr = readdir(dir)) != nullptr) {
+			if (ptr->d_type != DT_DIR)
+				continue;
+
+			string pname("/proc/" + string(ptr->d_name) + "/comm");
+			if (File::exists(pname.c_str())) {
+				ifstream pfile(pname.c_str());
+				string comm;
+				getline(pfile, comm);
+				pfile.close();
+
+				proxyPid = comm == proxyName ? string(ptr->d_name) : "";
+			}
+
+			if (!proxyPid.empty())
+				break;
+		}
+		closedir(dir);
+
+		if (!proxyPid.empty())
+			return atoi(proxyPid.c_str());
+
+		return -1;
+	}
+
+	int init() override
+	{
+		if (status_ != TestPass)
+			return status_;
+
+		config_ = camera_->generateConfiguration({ StreamRole::StillCapture });
+		if (!config_ || config_->size() != 1) {
+			cerr << "Failed to generate default configuration" << endl;
+			return TestFail;
+		}
+
+		allocator_ = make_unique<FrameBufferAllocator>(camera_);
+		allocated_ = false;
+
+		return TestPass;
+	}
+
+	int run() override
+	{
+		unsigned int openFdsAtStart = 0;
+		unsigned int openFds = 0;
+
+		pid_t proxyPid = findProxyPid();
+		if (proxyPid < 0) {
+			cerr << "Cannot find " << kIpaProxyName_
+			     << " pid, exiting" << endl;
+			return TestFail;
+		}
+
+		openFdsAtStart = fdsOpen(proxyPid);
+		for (unsigned int i = 0; i < kNumOfReconfigures_; i++) {
+			startAndStop();
+			openFds = fdsOpen(proxyPid);
+			if (openFds == 0) {
+				cerr << "No open fds found whereas "
+				     << "open fds at start: " << openFdsAtStart
+				     << endl;
+				return TestFail;
+			}
+
+			if (openFds != openFdsAtStart) {
+				cerr << "Leaking fds for " << kIpaProxyName_
+				     << " - Open fds: " << openFds << " vs "
+				     << "Open fds at start: " << openFdsAtStart
+				     << endl;
+				return TestFail;
+			}
+		}
+
+		return TestPass;
+	}
+
+	bool allocated_;
+
+	vector<unique_ptr<Request>> requests_;
+
+	unique_ptr<CameraConfiguration> config_;
+	unique_ptr<FrameBufferAllocator> allocator_;
+};
+
+} /* namespace */
+
+TEST_REGISTER(CameraReconfigure)
diff --git a/test/camera/meson.build b/test/camera/meson.build
index 002a87b5..668d5c03 100644
--- a/test/camera/meson.build
+++ b/test/camera/meson.build
@@ -8,6 +8,7 @@ camera_tests = [
     ['buffer_import',           'buffer_import.cpp'],
     ['statemachine',            'statemachine.cpp'],
     ['capture',                 'capture.cpp'],
+    ['camera_reconfigure',      'camera_reconfigure.cpp'],
 ]
 
 foreach t : camera_tests