test: logging: add logging process test

Add a test to test that logging works in isolated child processes.
Only logSetFile is tested, because stdout and stderr are closed for
isolated child processes, and syslog and the none logging destinations
are expected to be the same as non-isolated processes.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

test/log_process.cpp

@@ -0,0 +1,153 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * log_process.cpp - Logging in isolated child process test
+ */
+
+#include <fcntl.h>
+#include <iostream>
+#include <random>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <vector>
+
+#include <libcamera/camera_manager.h>
+#include <libcamera/event_dispatcher.h>
+#include <libcamera/logging.h>
+#include <libcamera/timer.h>
+
+#include "log.h"
+#include "process.h"
+#include "test.h"
+#include "utils.h"
+
+using namespace std;
+using namespace libcamera;
+
+static const string message("hello from the child");
+
+LOG_DEFINE_CATEGORY(LogProcessTest)
+
+class LogProcessTestChild
+{
+public:
+	int run(int status, int num)
+	{
+		usleep(50000);
+
+		string logPath = "/tmp/libcamera.worker.test." +
+				 to_string(num) + ".log";
+		if (logSetFile(logPath.c_str()) < 0)
+			return TestSkip;
+
+		LOG(LogProcessTest, Warning) << message;
+
+		return status;
+	}
+};
+
+class LogProcessTest : public Test
+{
+protected:
+	int init()
+	{
+		random_device random;
+		num_ = random();
+		logPath_ = "/tmp/libcamera.worker.test." +
+			   to_string(num_) + ".log";
+
+		proc_.finished.connect(this, &LogProcessTest::procFinished);
+		return 0;
+	}
+
+	int run()
+	{
+		EventDispatcher *dispatcher = CameraManager::instance()->eventDispatcher();
+		Timer timeout;
+
+		int exitCode = 42;
+		vector<std::string> args;
+		args.push_back(to_string(exitCode));
+		args.push_back(to_string(num_));
+		int ret = proc_.start("/proc/self/exe", args);
+		if (ret) {
+			cerr << "failed to start process" << endl;
+			return TestFail;
+		}
+
+		timeout.start(200);
+		while (timeout.isRunning())
+			dispatcher->processEvents();
+
+		if (exitStatus_ != Process::NormalExit) {
+			cerr << "process did not exit normally" << endl;
+			return TestFail;
+		}
+
+		if (exitCode_ == TestSkip)
+			return TestSkip;
+
+		if (exitCode_ != exitCode) {
+			cerr << "exit code should be " << exitCode
+			     << ", actual is " << exitCode_ << endl;
+			return TestFail;
+		}
+
+		int fd = open(logPath_.c_str(), O_RDONLY, S_IRUSR);
+		if (fd < 0) {
+			cerr << "failed to open tmp log file" << endl;
+			return TestFail;
+		}
+
+		char buf[200];
+		memset(buf, 0, sizeof(buf));
+		if (read(fd, buf, sizeof(buf)) < 0) {
+			cerr << "Failed to read tmp log file" << endl;
+			return TestFail;
+		}
+		close(fd);
+
+		string str(buf);
+		if (str.find(message) == string::npos)
+			return TestFail;
+
+		return TestPass;
+	}
+
+	void cleanup()
+	{
+		unlink(logPath_.c_str());
+	}
+
+private:
+	void procFinished(Process *proc, enum Process::ExitStatus exitStatus, int exitCode)
+	{
+		exitStatus_ = exitStatus;
+		exitCode_ = exitCode;
+	}
+
+	Process proc_;
+	Process::ExitStatus exitStatus_;
+	string logPath_;
+	int exitCode_;
+	int num_;
+};
+
+/*
+ * Can't use TEST_REGISTER() as single binary needs to act as both
+ * parent and child processes.
+ */
+int main(int argc, char **argv)
+{
+	if (argc == 3) {
+		int status = std::stoi(argv[1]);
+		int num = std::stoi(argv[2]);
+		LogProcessTestChild child;
+		return child.run(status, num);
+	}
+
+	return LogProcessTest().execute();
+}

test/meson.build

@@ -23,6 +23,7 @@ public_tests = [
 internal_tests = [
     ['camera-sensor',                   'camera-sensor.cpp'],
     ['log',                             'log.cpp'],
+    ['log_process',                     'log_process.cpp'],
     ['message',                         'message.cpp'],
     ['signal-threads',                  'signal-threads.cpp'],
     ['threads',                         'threads.cpp'],