[libcamera-devel] [PATCH 2/2] test: ipc: unix: Add test for IPCUnixSocket

[Laurent Pinchart]

Hi Niklas,

Thank you for the patch.

On Thu, Jun 27, 2019 at 04:09:55AM +0200, Niklas Söderlund wrote:
> Test that the IPC supports sending data and file descriptors over the
> IPC medium. To be able execute the test two parts are needed, one

s/To be able/To be able to/

> to drive the test and act as the libcamera (master) and a one to act as
> the IPA (slave).
> 
> The master drives the testing posting requests to the slave to process
> and sometime respond to. A few different tests are preformed.

s/sometime/sometimes/
s/preformed/performed/

> 
> - Master sends an array to the slave which responds with a reversed copy
>   of the array. The master verifies that a reversed array is returned.
> 
> - Master sends a list of file descriptors and ask the salve to calculate

s/salve/slave/

>   and respond with the sum of the size of the files. The master verifies
>   that the calculate size is correct.

s/calculate/calculated/

> 
> - Master send a pre-computed size and a list of file descriptors and

s/send/sends/

>   ask the slave to verify that the pre-computed size matches the sum of
>   the size of the file descriptors.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> ---
>  test/ipc/meson.build    |  12 ++
>  test/ipc/unixsocket.cpp | 339 ++++++++++++++++++++++++++++++++++++++++
>  test/meson.build        |   1 +
>  3 files changed, 352 insertions(+)
>  create mode 100644 test/ipc/meson.build
>  create mode 100644 test/ipc/unixsocket.cpp
> 
> diff --git a/test/ipc/meson.build b/test/ipc/meson.build
> new file mode 100644
> index 0000000000000000..ca8375f35df91731
> --- /dev/null
> +++ b/test/ipc/meson.build
> @@ -0,0 +1,12 @@
> +ipc_tests = [
> +    [ 'unixsocket',  'unixsocket.cpp' ],
> +]
> +
> +foreach t : ipc_tests
> +    exe = executable(t[0], t[1],
> +                     dependencies : libcamera_dep,
> +                     link_with : test_libraries,
> +                     include_directories : test_includes_internal)
> +
> +    test(t[0], exe, suite : 'ipc', is_parallel : false)
> +endforeach
> diff --git a/test/ipc/unixsocket.cpp b/test/ipc/unixsocket.cpp
> new file mode 100644
> index 0000000000000000..c50d7463cee48e75
> --- /dev/null
> +++ b/test/ipc/unixsocket.cpp
> @@ -0,0 +1,339 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2019, Google Inc.
> + *
> + * unixsocket.cpp - Unix socket IPC test
> + */
> +
> +#include <algorithm>
> +#include <atomic>
> +#include <fcntl.h>
> +#include <iostream>
> +#include <string.h>
> +#include <sys/wait.h>
> +#include <unistd.h>
> +
> +#include <libcamera/camera_manager.h>
> +#include <libcamera/event_dispatcher.h>
> +
> +#include "ipc_unixsocket.h"
> +#include "test.h"
> +
> +#define CMD_CLOSE 0
> +#define CMD_REVERSE 1
> +#define CMD_LEN_CALC 2
> +#define CMD_LEN_CMP 3

s/ \([0-9]\)/\t\1/

(tab instead of space to align the numbers)

> +
> +using namespace std;
> +using namespace libcamera;
> +
> +int calcLength(int fd)

s/calcLength/calculateLength/

> +{
> +	lseek(fd, 0, 0);
> +	int size = lseek(fd, 0, SEEK_END);
> +	lseek(fd, 0, 0);
> +
> +	return size;
> +}
> +
> +class UnixSocketTestSlave
> +{
> +public:
> +	UnixSocketTestSlave()
> +		: exitCode_(EXIT_FAILURE)
> +	{
> +		dispatcher_ = CameraManager::instance()->eventDispatcher();
> +		exit_.store(false, std::memory_order_release);

With a single process you can use a bool for exit_ and assign it
directly.

> +		ipc_.payloadReceived.connect(this, &UnixSocketTestSlave::payloadReceived);
> +	}
> +
> +	int run(int fd)
> +	{
> +		if (ipc_.attach(fd)) {
> +			cerr << "Failed to connect to IPC" << endl;

s/IPC/IPC channel/

> +			return EXIT_FAILURE;
> +		}
> +
> +		while (!exit_.load(std::memory_order_acquire))
> +			dispatcher_->processEvents();
> +
> +		ipc_.close();
> +
> +		return exitCode_;
> +	}
> +
> +private:
> +	void payloadReceived(const IPCUnixSocket::Payload &payload)
> +	{
> +		IPCUnixSocket::Payload response;
> +		int ret;
> +
> +		const uint8_t cmd = payload.data.front();

data[0] would be more explicit.

> +
> +		cout << "Slave received command " << static_cast<unsigned int>(cmd) << endl;
> +
> +		switch (cmd) {
> +		case CMD_CLOSE:
> +			stop(0);
> +			break;

A blank line between each case would make it easier to read.

> +		case CMD_REVERSE: {
> +			std::vector<uint8_t> raw(payload.data.begin() + 1, payload.data.end());
> +			std::reverse(raw.begin(), raw.end());
> +			raw.insert(raw.begin(), cmd);
> +
> +			response.data = raw;

			response.data = payload.data;
			std::reverse(response.data.begin() + 1, response.data.end());

> +			ret = ipc_.send(response);
> +			if (ret < 0) {
> +				cerr << "Reverse fail" << endl;
> +				stop(ret);
> +			}
> +			break;
> +		}
> +		case CMD_LEN_CALC: {
> +			int size = 0;
> +			for (int fd : payload.fds)
> +				size += calcLength(fd);
> +
> +			response.data.resize(1 + sizeof(size));
> +			response.data[0] = cmd;
> +			memcpy(response.data.data() + 1, &size, sizeof(size));
> +
> +			ret = ipc_.send(response);
> +			if (ret < 0) {
> +				cerr << "Calc fail" << endl;
> +				stop(ret);
> +			}
> +			break;
> +		}
> +		case CMD_LEN_CMP: {
> +			int size = 0;
> +			for (int fd : payload.fds)
> +				size += calcLength(fd);
> +
> +			int cmp;
> +			memcpy(&cmp, payload.data.data() + 1, sizeof(cmp));
> +
> +			if (cmp != size) {
> +				cerr << "Compare fail" << endl;
> +				stop(-ERANGE);
> +			}
> +			break;
> +		}
> +		default:
> +			cerr << "Unknown command " << cmd << endl;
> +			stop(-EINVAL);

Missing break.

> +		}
> +	}
> +
> +	void stop(int code)
> +	{
> +		exitCode_ = code;
> +		exit_.store(true, std::memory_order_release);
> +	}
> +
> +	IPCUnixSocket ipc_;
> +	EventDispatcher *dispatcher_;
> +	int exitCode_;
> +	std::atomic<bool> exit_;
> +};
> +
> +static const std::vector<std::string> testPaths = {
> +	"/proc/self/exe",
> +	"/proc/self/exe",
> +};
> +
> +class UnixSocketTest : public Test
> +{
> +protected:
> +	int slaveStart(int fd)
> +	{
> +		pid_ = fork();
> +
> +		if (pid_ == -1)
> +			return TestFail;
> +
> +		if (!pid_) {
> +			std::string arg = std::to_string(fd);
> +			execl("/proc/self/exe", "/proc/self/exe",
> +			      arg.c_str(), nullptr);
> +
> +			/* Only get here if exec fails. */
> +			exit(TestFail);
> +		}
> +
> +		return TestPass;
> +	}
> +
> +	int slaveStop()
> +	{
> +		int status;
> +
> +		if (pid_ < 0)
> +			return TestFail;
> +
> +		if (waitpid(pid_, &status, 0) < 0)
> +			return TestFail;
> +
> +		if (!WIFEXITED(status) || WEXITSTATUS(status))
> +			return TestFail;
> +
> +		return TestPass;
> +	}
> +
> +	int testReverse()
> +	{
> +		IPCUnixSocket::Payload reverse;
> +
> +		reverse.data = { CMD_REVERSE, 1, 2, 3, 4, 5 };
> +		if (ipc_.send(reverse))
> +			return TestFail;
> +
> +		CameraManager::instance()->eventDispatcher()->processEvents();

I think you should create a call() helper method that take a payload,
sends it, calls processEvents() in a loop until a response is received
(I would add a Timer to make sure we time out), and return the response.
That will simplify the logic of the rest of the tests, allowing you to
move the checks from payloadReceived() to the individual test methods.

> +
> +		return 0;
> +	}
> +
> +	int testCalc()
> +	{
> +		IPCUnixSocket::Payload payload;
> +
> +		calcSize_ = 0;
> +		for (const std::string path : testPaths) {
> +			int fd = open(path.c_str(), O_RDONLY);
> +			if (fd < 0)
> +				return TestFail;
> +
> +			calcSize_ += calcLength(fd);
> +			payload.fds.push_back(fd);
> +		}
> +
> +		payload.data.push_back(CMD_LEN_CALC);
> +		if (ipc_.send(payload))
> +			return TestFail;
> +
> +		CameraManager::instance()->eventDispatcher()->processEvents();
> +
> +		return 0;
> +	}
> +
> +	int testCmp()
> +	{
> +		IPCUnixSocket::Payload payload;
> +
> +		int size = 0;
> +		for (const std::string path : testPaths) {
> +			int fd = open(path.c_str(), O_RDONLY);
> +			if (fd < 0)
> +				return TestFail;
> +
> +			size += calcLength(fd);
> +			payload.fds.push_back(fd);
> +		}
> +
> +		payload.data.resize(1 + sizeof(size));
> +		payload.data[0] = CMD_LEN_CMP;
> +		memcpy(payload.data.data() + 1, &size, sizeof(size));
> +
> +		if (ipc_.send(payload))
> +			return TestFail;
> +
> +		return 0;
> +	}
> +
> +	int run()
> +	{
> +		int slavefd = ipc_.create();
> +		if (slavefd < 0)
> +			return TestFail;

Please print an error message when a failure is returned.

> +
> +		if (slaveStart(slavefd))
> +			return TestFail;
> +
> +		ipc_.payloadReceived.connect(this, &UnixSocketTest::payloadReceived);
> +
> +		/* Test reversing a string, this test sending only data. */
> +		ranRev_ = false;
> +		if (testReverse())
> +			return TestFail;
> +
> +		/* Test offloading a calculation, this test sending only FDs. */
> +		ranCalc_ = false;
> +		if (testCalc())
> +			return TestFail;
> +
> +		/* Test fire and forget, this tests sending data and FDs. */
> +		if (testCmp())
> +			return TestFail;
> +
> +		/* Close slave connection. */
> +		IPCUnixSocket::Payload close;
> +		close.data.push_back(CMD_CLOSE);
> +		if (ipc_.send(close))
> +			return TestFail;
> +
> +		ipc_.close();
> +		if (slaveStop())
> +			return TestFail;
> +
> +		/* Check that all tests have executed. */
> +		if (!ranRev_ || !ranCalc_) {
> +			cerr << "Not all messages responded to" << endl;
> +			return TestFail;
> +		}
> +
> +		return TestPass;
> +	}
> +
> +private:
> +	void payloadReceived(const IPCUnixSocket::Payload &payload)
> +	{
> +		const uint8_t cmd = payload.data.front();
> +		cout << "Master received command " << static_cast<unsigned int>(cmd) << endl;
> +
> +		switch (cmd) {
> +		case CMD_REVERSE: {
> +			std::vector<uint8_t> raw(payload.data.begin() + 1, payload.data.end());
> +			if (raw == std::vector<uint8_t>{ 5, 4, 3, 2, 1 })
> +				ranRev_ = true;
> +			else
> +				cerr << "Reverse response invalid" << endl;
> +
> +			break;
> +		}
> +		case CMD_LEN_CALC: {
> +			int output;
> +			memcpy(&output, payload.data.data() + 1, sizeof(output));
> +			if (output == calcSize_)
> +				ranCalc_ = true;
> +			else
> +				cerr << "Calc response invalid" << endl;
> +
> +			break;
> +		}
> +		default:
> +			cerr << "Unknown command " << cmd << endl;
> +		}
> +	}
> +
> +	pid_t pid_;
> +	IPCUnixSocket ipc_;
> +
> +	bool ranRev_;
> +	bool ranCalc_;
> +	int calcSize_;
> +};
> +
> +/*
> + * Can't use TEST_REGISTER() as single binary needs to act as both proxy
> + * master and slave.
> + */
> +int main(int argc, char **argv)
> +{
> +	if (argc == 2) {
> +		int ipcfd = std::stoi(argv[1]);
> +		UnixSocketTestSlave slave;
> +		return slave.run(ipcfd);
> +	}
> +
> +	return UnixSocketTest().execute();
> +}
> diff --git a/test/meson.build b/test/meson.build
> index c36ac24796367501..3666f6b2385bd4ca 100644
> --- a/test/meson.build
> +++ b/test/meson.build
> @@ -2,6 +2,7 @@ subdir('libtest')
>  
>  subdir('camera')
>  subdir('ipa')
> +subdir('ipc')
>  subdir('media_device')
>  subdir('pipeline')
>  subdir('stream')

-- 
Regards,

Laurent Pinchart