[libcamera-devel] [RFC PATCH] test: camera: Camera reconfiguration and fd-leak test

[Umang Jain]

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

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

This test is geared towards reproducing [1], issue noticed on IPU3.

Ensure that test is run in isolated mode.
Running standalone:
$ LIBCAMERA_IPA_FORCE_ISOLATION=1 ./build/test/camera/camera_reconfigure

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

Signed-off-by: Umang Jain <umang.jain at ideasonboard.com>
---
- still RFC because it's based on "Pass buffers to VIMC IPA" series
- We probably need to set LIBCAMERA_IPA_FORCE_ISOLATION=1 from inside
  the test. Setting at run-time with setenv(), sets the env var but still
  the test is unable to run in isolated mode. For now, I only have it
  working, by running it standalone as mentioned in the commit message.
  OR any other ideas enforcing isolated mode on the test?
- Some sprinkled prints are intentionally present, will be reworked in
  v1. Please ignore those for review.
  (log snippet: https://paste.debian.net/1206765/)
---
 test/camera/camera_reconfigure.cpp | 250 +++++++++++++++++++++++++++++
 test/camera/meson.build            |   1 +
 2 files changed, 251 insertions(+)
 create mode 100644 test/camera/camera_reconfigure.cpp

diff --git a/test/camera/camera_reconfigure.cpp b/test/camera/camera_reconfigure.cpp
new file mode 100644
index 00000000..20a4a6a4
--- /dev/null
+++ b/test/camera/camera_reconfigure.cpp
@@ -0,0 +1,250 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * Test:
+ * - Camera's multiple reconfigurations without stopping CameraManager
+ * - leaking fds across IPA IPC boundary
+ */
+
+#include <dirent.h>
+#include <iostream>
+#include <fstream>
+
+#include <libcamera/framebuffer_allocator.h>
+
+#include <libcamera/base/event_dispatcher.h>
+#include <libcamera/base/file.h>
+#include <libcamera/base/thread.h>
+#include <libcamera/base/timer.h>
+
+#include "camera_test.h"
+#include "test.h"
+
+using namespace std;
+
+#define CAM_ID			"platform/vimc.0 Sensor B"
+#define IPA_PROXY_NAME		"vimc_ipa_proxy"
+#define NUM_OF_RECONFIGURES	20
+
+namespace {
+
+class CameraReconfigure : public CameraTest, public Test
+{
+public:
+	CameraReconfigure()
+		: CameraTest(CAM_ID)
+	{
+	}
+
+protected:
+	unsigned int configureRuns_;
+	unsigned int openFdsAtStart_;
+	string vimcProxyName_;
+	bool allocated_;
+
+	vector<unique_ptr<Request>> requests_;
+
+	unique_ptr<CameraConfiguration> config_;
+	FrameBufferAllocator *allocator_;
+
+	void requestComplete(Request *request)
+	{
+		if (request->status() != Request::RequestComplete)
+			return;
+
+		const Request::BufferMap &buffers = request->buffers();
+
+		/* Create a new request. */
+		const Stream *stream = buffers.begin()->first;
+		FrameBuffer *buffer = buffers.begin()->second;
+
+		request->reuse();
+		request->addBuffer(stream, buffer);
+		camera_->queueRequest(request);
+	}
+
+	int startAndStop ()
+	{
+		StreamConfiguration &cfg = config_->at(0);
+
+		if (camera_->acquire()) {
+			cout << "Failed to acquire the camera" << endl;
+			return TestFail;
+		}
+
+		if (camera_->configure(config_.get())) {
+			cout << "Failed to set default configuration" << endl;
+			return TestFail;
+		}
+
+		Stream *stream = cfg.stream();
+
+		if (!allocated_) {
+			int ret = allocator_->allocate(stream);
+			if (ret < 0)
+				return TestFail;
+			allocated_ = true;
+		}
+
+		for (const unique_ptr<FrameBuffer> &buffer : allocator_->buffers(stream)) {
+			unique_ptr<Request> request = camera_->createRequest();
+			if (!request) {
+				cout << "Failed to create request" << endl;
+				return TestFail;
+			}
+
+			if (request->addBuffer(stream, buffer.get())) {
+				cout << "Failed to associating buffer with request" << endl;
+				return TestFail;
+			}
+
+			requests_.push_back(move(request));
+		}
+
+		camera_->requestCompleted.connect(this, &CameraReconfigure::requestComplete);
+
+		if (camera_->start()) {
+			cout << "Failed to start camera" << endl;
+			return TestFail;
+		}
+
+		for (unique_ptr<Request> &request : requests_) {
+			if (camera_->queueRequest(request.get())) {
+				cout << "Failed to queue request" << endl;
+				return TestFail;
+			}
+		}
+
+		EventDispatcher *dispatcher = Thread::current()->eventDispatcher();
+
+		Timer timer;
+		timer.start(1000);
+		while (timer.isRunning())
+			dispatcher->processEvents();
+
+		if (camera_->stop()) {
+			cout << "Failed to stop camera" << endl;
+			return TestFail;
+		}
+
+		if (camera_->release()) {
+			cout << "Failed to release camera" << endl;
+			return TestFail;
+		}
+
+		camera_->requestCompleted.disconnect(this, &CameraReconfigure::requestComplete);
+
+		requests_.clear();
+
+		return 0;
+	}
+
+	int fdsOpen(string pid)
+	{
+		string proxyFdPath = "/proc/" + pid + "/fd";
+		DIR *dir;
+		struct dirent *ptr;
+		unsigned int openFds = 0;
+
+		dir = opendir(proxyFdPath.c_str());
+		while((ptr = readdir(dir)) != nullptr) {
+			if ((strcmp(ptr->d_name, ".") == 0) || (strcmp(ptr->d_name, "..") == 0))
+				continue;
+
+			openFds++;
+		}
+		closedir(dir);
+
+		return openFds;
+	}
+
+	string findProxyPid()
+	{
+		string proxyPid;
+		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 == vimcProxyName_ ?
+					   string(ptr->d_name) :
+					   "";
+			}
+
+			if (!proxyPid.empty())
+				break;
+		}
+		closedir(dir);
+
+		return proxyPid;
+	}
+
+	int init() override
+	{
+		if (status_ != TestPass)
+			return status_;
+
+		config_ = camera_->generateConfiguration({ StreamRole::StillCapture });
+		if (!config_ || config_->size() != 1) {
+			cout << "Failed to generate default configuration" << endl;
+			return TestFail;
+		}
+
+		allocator_ = new FrameBufferAllocator(camera_);
+
+		openFdsAtStart_ = 0;
+		configureRuns_ = NUM_OF_RECONFIGURES;
+		vimcProxyName_ = IPA_PROXY_NAME;
+		allocated_ = false;
+
+		return TestPass;
+	}
+
+	void cleanup() override
+	{
+		delete allocator_;
+	}
+
+	int run() override
+	{
+		unsigned int openFds = 0;
+		/* Find pid of vimc_ipa_proxy */
+		string proxyPid = findProxyPid();
+		if (proxyPid.empty()) {
+			cout << "Not running in isolated mode, exiting" << endl;
+			return TestFail;
+		}
+
+		/* Find number of open fds  by vimc_ipa_proxy */
+		openFdsAtStart_ = fdsOpen(proxyPid);
+		cout << IPA_PROXY_NAME << " PID:" << proxyPid
+			<< " has open fds at start:"  << openFdsAtStart_ << endl;
+
+		for (unsigned int i = 0; i < configureRuns_; i++)
+		{
+			startAndStop();
+			openFds = fdsOpen(proxyPid);
+			cout << "No. of open fds after #" << i << " runs: " << openFds << endl;
+		}
+
+		if (openFds == openFdsAtStart_)
+			return TestPass;
+		else
+			return TestFail;
+	}
+};
+
+} /* 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
-- 
2.31.1