[libcamera-devel] [PATCH v4 10/22] libcamera: ipc_unixsocket: Use UniqueFD for a file descriptor

Jacopo Mondi jacopo at jmondi.org
Tue Nov 30 08:54:26 CET 2021


Hi Laurent,

On Tue, Nov 30, 2021 at 05:38:08AM +0200, Laurent Pinchart wrote:
> From: Hirokazu Honda <hiroh at chromium.org>
>
> IPCUnixSocket::create() creates two file descriptors. One of
> them is stored in IPCUnixSocket and the other is returned to a
> caller. This clarifies the ownership using UniqueFD.
>
> Signed-off-by: Hirokazu Honda <hiroh at chromium.org>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Reviewed-by: Hirokazu Honda <hiroh at chromium.org>

Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
  j

> ---
> Changes since v2:
>
> - Pass UniqueFD to IPCUnixSocket::bind()
> - Return {}
> ---
>  include/libcamera/internal/ipc_unixsocket.h   |  7 +--
>  src/libcamera/ipc_pipe_unixsocket.cpp         |  8 ++--
>  src/libcamera/ipc_unixsocket.cpp              | 43 ++++++++++---------
>  test/ipc/unixsocket.cpp                       | 14 +++---
>  test/ipc/unixsocket_ipc.cpp                   |  8 ++--
>  .../module_ipa_proxy_worker.cpp.tmpl          | 13 +++---
>  6 files changed, 49 insertions(+), 44 deletions(-)
>
> diff --git a/include/libcamera/internal/ipc_unixsocket.h b/include/libcamera/internal/ipc_unixsocket.h
> index 5010b66a2bda..3963d182ffa6 100644
> --- a/include/libcamera/internal/ipc_unixsocket.h
> +++ b/include/libcamera/internal/ipc_unixsocket.h
> @@ -12,6 +12,7 @@
>  #include <vector>
>
>  #include <libcamera/base/signal.h>
> +#include <libcamera/base/unique_fd.h>
>
>  namespace libcamera {
>
> @@ -28,8 +29,8 @@ public:
>  	IPCUnixSocket();
>  	~IPCUnixSocket();
>
> -	int create();
> -	int bind(int fd);
> +	UniqueFD create();
> +	int bind(UniqueFD fd);
>  	void close();
>  	bool isBound() const;
>
> @@ -49,7 +50,7 @@ private:
>
>  	void dataNotifier();
>
> -	int fd_;
> +	UniqueFD fd_;
>  	bool headerReceived_;
>  	struct Header header_;
>  	EventNotifier *notifier_;
> diff --git a/src/libcamera/ipc_pipe_unixsocket.cpp b/src/libcamera/ipc_pipe_unixsocket.cpp
> index 533560cf95d3..65277500ff42 100644
> --- a/src/libcamera/ipc_pipe_unixsocket.cpp
> +++ b/src/libcamera/ipc_pipe_unixsocket.cpp
> @@ -31,14 +31,14 @@ IPCPipeUnixSocket::IPCPipeUnixSocket(const char *ipaModulePath,
>  	args.push_back(ipaModulePath);
>
>  	socket_ = std::make_unique<IPCUnixSocket>();
> -	int fd = socket_->create();
> -	if (fd < 0) {
> +	UniqueFD fd = socket_->create();
> +	if (!fd.isValid()) {
>  		LOG(IPCPipe, Error) << "Failed to create socket";
>  		return;
>  	}
>  	socket_->readyRead.connect(this, &IPCPipeUnixSocket::readyRead);
> -	args.push_back(std::to_string(fd));
> -	fds.push_back(fd);
> +	args.push_back(std::to_string(fd.get()));
> +	fds.push_back(fd.release());
>
>  	proc_ = std::make_unique<Process>();
>  	int ret = proc_->start(ipaProxyWorkerPath, args, fds);
> diff --git a/src/libcamera/ipc_unixsocket.cpp b/src/libcamera/ipc_unixsocket.cpp
> index bd32fca3a678..1980d374cea8 100644
> --- a/src/libcamera/ipc_unixsocket.cpp
> +++ b/src/libcamera/ipc_unixsocket.cpp
> @@ -7,6 +7,7 @@
>
>  #include "libcamera/internal/ipc_unixsocket.h"
>
> +#include <array>
>  #include <poll.h>
>  #include <string.h>
>  #include <sys/socket.h>
> @@ -68,7 +69,7 @@ LOG_DEFINE_CATEGORY(IPCUnixSocket)
>   */
>
>  IPCUnixSocket::IPCUnixSocket()
> -	: fd_(-1), headerReceived_(false), notifier_(nullptr)
> +	: headerReceived_(false), notifier_(nullptr)
>  {
>  }
>
> @@ -86,9 +87,9 @@ IPCUnixSocket::~IPCUnixSocket()
>   * to the remote process, where it can be used with IPCUnixSocket::bind() to
>   * bind the remote side socket.
>   *
> - * \return A file descriptor on success, negative error code on failure
> + * \return A file descriptor. It is valid on success or invalid otherwise.
>   */
> -int IPCUnixSocket::create()
> +UniqueFD IPCUnixSocket::create()
>  {
>  	int sockets[2];
>  	int ret;
> @@ -98,14 +99,18 @@ int IPCUnixSocket::create()
>  		ret = -errno;
>  		LOG(IPCUnixSocket, Error)
>  			<< "Failed to create socket pair: " << strerror(-ret);
> -		return ret;
> +		return {};
>  	}
>
> -	ret = bind(sockets[0]);
> -	if (ret)
> -		return ret;
> +	std::array<UniqueFD, 2> socketFds{
> +		UniqueFD(sockets[0]),
> +		UniqueFD(sockets[1]),
> +	};
>
> -	return sockets[1];
> +	if (bind(std::move(socketFds[0])) < 0)
> +		return {};
> +
> +	return std::move(socketFds[1]);
>  }
>
>  /**
> @@ -118,13 +123,13 @@ int IPCUnixSocket::create()
>   *
>   * \return 0 on success or a negative error code otherwise
>   */
> -int IPCUnixSocket::bind(int fd)
> +int IPCUnixSocket::bind(UniqueFD fd)
>  {
>  	if (isBound())
>  		return -EINVAL;
>
> -	fd_ = fd;
> -	notifier_ = new EventNotifier(fd_, EventNotifier::Read);
> +	fd_ = std::move(fd);
> +	notifier_ = new EventNotifier(fd_.get(), EventNotifier::Read);
>  	notifier_->activated.connect(this, &IPCUnixSocket::dataNotifier);
>
>  	return 0;
> @@ -143,9 +148,7 @@ void IPCUnixSocket::close()
>  	delete notifier_;
>  	notifier_ = nullptr;
>
> -	::close(fd_);
> -
> -	fd_ = -1;
> +	fd_.reset();
>  	headerReceived_ = false;
>  }
>
> @@ -155,7 +158,7 @@ void IPCUnixSocket::close()
>   */
>  bool IPCUnixSocket::isBound() const
>  {
> -	return fd_ != -1;
> +	return fd_.isValid();
>  }
>
>  /**
> @@ -182,7 +185,7 @@ int IPCUnixSocket::send(const Payload &payload)
>  	if (!hdr.data && !hdr.fds)
>  		return -EINVAL;
>
> -	ret = ::send(fd_, &hdr, sizeof(hdr), 0);
> +	ret = ::send(fd_.get(), &hdr, sizeof(hdr), 0);
>  	if (ret < 0) {
>  		ret = -errno;
>  		LOG(IPCUnixSocket, Error)
> @@ -263,7 +266,7 @@ int IPCUnixSocket::sendData(const void *buffer, size_t length,
>  	if (fds)
>  		memcpy(CMSG_DATA(cmsg), fds, num * sizeof(uint32_t));
>
> -	if (sendmsg(fd_, &msg, 0) < 0) {
> +	if (sendmsg(fd_.get(), &msg, 0) < 0) {
>  		int ret = -errno;
>  		LOG(IPCUnixSocket, Error)
>  			<< "Failed to sendmsg: " << strerror(-ret);
> @@ -297,7 +300,7 @@ int IPCUnixSocket::recvData(void *buffer, size_t length,
>  	msg.msg_controllen = cmsg->cmsg_len;
>  	msg.msg_flags = 0;
>
> -	if (recvmsg(fd_, &msg, 0) < 0) {
> +	if (recvmsg(fd_.get(), &msg, 0) < 0) {
>  		int ret = -errno;
>  		if (ret != -EAGAIN)
>  			LOG(IPCUnixSocket, Error)
> @@ -317,7 +320,7 @@ void IPCUnixSocket::dataNotifier()
>
>  	if (!headerReceived_) {
>  		/* Receive the header. */
> -		ret = ::recv(fd_, &header_, sizeof(header_), 0);
> +		ret = ::recv(fd_.get(), &header_, sizeof(header_), 0);
>  		if (ret < 0) {
>  			ret = -errno;
>  			LOG(IPCUnixSocket, Error)
> @@ -333,7 +336,7 @@ void IPCUnixSocket::dataNotifier()
>  	 * readyRead signal. The notifier will be reenabled by the receive()
>  	 * function.
>  	 */
> -	struct pollfd fds = { fd_, POLLIN, 0 };
> +	struct pollfd fds = { fd_.get(), POLLIN, 0 };
>  	ret = poll(&fds, 1, 0);
>  	if (ret < 0)
>  		return;
> diff --git a/test/ipc/unixsocket.cpp b/test/ipc/unixsocket.cpp
> index 7270bf4d2fe7..414f1bfc9d12 100644
> --- a/test/ipc/unixsocket.cpp
> +++ b/test/ipc/unixsocket.cpp
> @@ -52,9 +52,9 @@ public:
>  		ipc_.readyRead.connect(this, &UnixSocketTestSlave::readyRead);
>  	}
>
> -	int run(int fd)
> +	int run(UniqueFD fd)
>  	{
> -		if (ipc_.bind(fd)) {
> +		if (ipc_.bind(std::move(fd))) {
>  			cerr << "Failed to connect to IPC channel" << endl;
>  			return EXIT_FAILURE;
>  		}
> @@ -360,11 +360,11 @@ protected:
>
>  	int run()
>  	{
> -		int slavefd = ipc_.create();
> -		if (slavefd < 0)
> +		UniqueFD slavefd = ipc_.create();
> +		if (!slavefd.isValid())
>  			return TestFail;
>
> -		if (slaveStart(slavefd)) {
> +		if (slaveStart(slavefd.release())) {
>  			cerr << "Failed to start slave" << endl;
>  			return TestFail;
>  		}
> @@ -496,9 +496,9 @@ private:
>  int main(int argc, char **argv)
>  {
>  	if (argc == 2) {
> -		int ipcfd = std::stoi(argv[1]);
> +		UniqueFD ipcfd = UniqueFD(std::stoi(argv[1]));
>  		UnixSocketTestSlave slave;
> -		return slave.run(ipcfd);
> +		return slave.run(std::move(ipcfd));
>  	}
>
>  	return UnixSocketTest().execute();
> diff --git a/test/ipc/unixsocket_ipc.cpp b/test/ipc/unixsocket_ipc.cpp
> index ab5d25572d83..178ee1870056 100644
> --- a/test/ipc/unixsocket_ipc.cpp
> +++ b/test/ipc/unixsocket_ipc.cpp
> @@ -49,9 +49,9 @@ public:
>  		ipc_.readyRead.connect(this, &UnixSocketTestIPCSlave::readyRead);
>  	}
>
> -	int run(int fd)
> +	int run(UniqueFD fd)
>  	{
> -		if (ipc_.bind(fd)) {
> +		if (ipc_.bind(std::move(fd))) {
>  			cerr << "Failed to connect to IPC channel" << endl;
>  			return EXIT_FAILURE;
>  		}
> @@ -222,9 +222,9 @@ int main(int argc, char **argv)
>  {
>  	/* IPCPipeUnixSocket passes IPA module path in argv[1] */
>  	if (argc == 3) {
> -		int ipcfd = std::stoi(argv[2]);
> +		UniqueFD ipcfd = UniqueFD(std::stoi(argv[2]));
>  		UnixSocketTestIPCSlave slave;
> -		return slave.run(ipcfd);
> +		return slave.run(std::move(ipcfd));
>  	}
>
>  	return UnixSocketTestIPC().execute();
> diff --git a/utils/ipc/generators/libcamera_templates/module_ipa_proxy_worker.cpp.tmpl b/utils/ipc/generators/libcamera_templates/module_ipa_proxy_worker.cpp.tmpl
> index 764e7a3af63a..b65dc4cf31c5 100644
> --- a/utils/ipc/generators/libcamera_templates/module_ipa_proxy_worker.cpp.tmpl
> +++ b/utils/ipc/generators/libcamera_templates/module_ipa_proxy_worker.cpp.tmpl
> @@ -27,8 +27,9 @@
>  #include <libcamera/logging.h>
>
>  #include <libcamera/base/event_dispatcher.h>
> -#include <libcamera/base/thread.h>
>  #include <libcamera/base/log.h>
> +#include <libcamera/base/thread.h>
> +#include <libcamera/base/unique_fd.h>
>
>  #include "libcamera/internal/camera_sensor.h"
>  #include "libcamera/internal/control_serializer.h"
> @@ -122,9 +123,9 @@ public:
>  		}
>  	}
>
> -	int init(std::unique_ptr<IPAModule> &ipam, int socketfd)
> +	int init(std::unique_ptr<IPAModule> &ipam, UniqueFD socketfd)
>  	{
> -		if (socket_.bind(socketfd) < 0) {
> +		if (socket_.bind(std::move(socketfd)) < 0) {
>  			LOG({{proxy_worker_name}}, Error)
>  				<< "IPC socket binding failed";
>  			return EXIT_FAILURE;
> @@ -203,10 +204,10 @@ int main(int argc, char **argv)
>  		return EXIT_FAILURE;
>  	}
>
> -	int fd = std::stoi(argv[2]);
> +	UniqueFD fd(std::stoi(argv[2]));
>  	LOG({{proxy_worker_name}}, Info)
>  		<< "Starting worker for IPA module " << argv[1]
> -		<< " with IPC fd = " << fd;
> +		<< " with IPC fd = " << fd.get();
>
>  	std::unique_ptr<IPAModule> ipam = std::make_unique<IPAModule>(argv[1]);
>  	if (!ipam->isValid() || !ipam->load()) {
> @@ -228,7 +229,7 @@ int main(int argc, char **argv)
>  	}
>
>  	{{proxy_worker_name}} proxyWorker;
> -	int ret = proxyWorker.init(ipam, fd);
> +	int ret = proxyWorker.init(ipam, std::move(fd));
>  	if (ret < 0) {
>  		LOG({{proxy_worker_name}}, Error)
>  			<< "Failed to initialize proxy worker";
> --
> Regards,
>
> Laurent Pinchart
>


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