From f2ce8c3b62cedd0ae7cba1c3b9e2d1cec9a750a8 Mon Sep 17 00:00:00 2001 From: Max Kellermann Date: Wed, 7 Aug 2013 11:52:26 +0200 Subject: event/EventFD: move to libsystem --- src/system/EventFD.cxx | 65 +++++++++++++++++ src/system/EventFD.hxx | 57 +++++++++++++++ src/system/EventPipe.cxx | 180 +++++++++++++++++++++++++++++++++++++++++++++++ src/system/EventPipe.hxx | 57 +++++++++++++++ 4 files changed, 359 insertions(+) create mode 100644 src/system/EventFD.cxx create mode 100644 src/system/EventFD.hxx create mode 100644 src/system/EventPipe.cxx create mode 100644 src/system/EventPipe.hxx (limited to 'src/system') diff --git a/src/system/EventFD.cxx b/src/system/EventFD.cxx new file mode 100644 index 000000000..716ff80ae --- /dev/null +++ b/src/system/EventFD.cxx @@ -0,0 +1,65 @@ +/* + * Copyright (C) 2003-2013 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "config.h" +#ifdef USE_EVENTFD +#include "EventFD.hxx" +#include "system/fd_util.h" +#include "system/FatalError.hxx" +#include "gcc.h" + +#include +#include + +#include + +EventFD::EventFD() + :fd(eventfd_cloexec_nonblock(0, 0)) +{ + if (fd < 0) + FatalSystemError("eventfd() failed"); +} + +EventFD::~EventFD() +{ + assert(fd >= 0); + + close(fd); +} + +bool +EventFD::Read() +{ + assert(fd >= 0); + + eventfd_t value; + return read(fd, &value, sizeof(value)) == (ssize_t)sizeof(value); +} + +void +EventFD::Write() +{ + assert(fd >= 0); + + static constexpr eventfd_t value = 1; + gcc_unused ssize_t nbytes = + write(fd, &value, sizeof(value)); +} + +#endif /* USE_EVENTFD */ diff --git a/src/system/EventFD.hxx b/src/system/EventFD.hxx new file mode 100644 index 000000000..67a0258ab --- /dev/null +++ b/src/system/EventFD.hxx @@ -0,0 +1,57 @@ +/* + * Copyright (C) 2003-2013 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef MPD_EVENT_FD_HXX +#define MPD_EVENT_FD_HXX + +#include "check.h" + +/** + * A class that wraps eventfd(). + * + * Errors in the constructor are fatal. + */ +class EventFD { + int fd; + +public: + EventFD(); + ~EventFD(); + + EventFD(const EventFD &other) = delete; + EventFD &operator=(const EventFD &other) = delete; + + int Get() const { + return fd; + } + + /** + * Checks if Write() was called at least once since the last + * Read() call. + */ + bool Read(); + + /** + * Wakes up the reader. Multiple calls to this function will + * be combined to one wakeup. + */ + void Write(); +}; + +#endif diff --git a/src/system/EventPipe.cxx b/src/system/EventPipe.cxx new file mode 100644 index 000000000..e1a38c503 --- /dev/null +++ b/src/system/EventPipe.cxx @@ -0,0 +1,180 @@ +/* + * Copyright (C) 2003-2013 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include "config.h" +#include "EventPipe.hxx" +#include "system/fd_util.h" +#include "system/FatalError.hxx" +#include "gcc.h" + +#include +#include + +#ifdef WIN32 +#include +#include +#include /* for memset() */ +#endif + +#ifdef WIN32 +static bool PoorSocketPair(int fd[2]); +#endif + +EventPipe::EventPipe() +{ +#ifdef WIN32 + bool success = PoorSocketPair(fds); +#else + bool success = pipe_cloexec_nonblock(fds) >= 0; +#endif + if (!success) + FatalSystemError("pipe() has failed"); +} + +EventPipe::~EventPipe() +{ +#ifdef WIN32 + closesocket(fds[0]); + closesocket(fds[1]); +#else + close(fds[0]); + close(fds[1]); +#endif +} + +bool +EventPipe::Read() +{ + assert(fds[0] >= 0); + assert(fds[1] >= 0); + + char buffer[256]; +#ifdef WIN32 + return recv(fds[0], buffer, sizeof(buffer), 0) > 0; +#else + return read(fds[0], buffer, sizeof(buffer)) > 0; +#endif +} + +void +EventPipe::Write() +{ + assert(fds[0] >= 0); + assert(fds[1] >= 0); + +#ifdef WIN32 + send(fds[1], "", 1, 0); +#else + gcc_unused ssize_t nbytes = write(fds[1], "", 1); +#endif +} + +#ifdef WIN32 + +static void SafeCloseSocket(SOCKET s) +{ + int error = WSAGetLastError(); + closesocket(s); + WSASetLastError(error); +} + +/* Our poor man's socketpair() implementation + * Due to limited protocol/address family support and primitive error handling + * it's better to keep this as a private implementation detail of EventPipe + * rather than wide-available API. + */ +static bool PoorSocketPair(int fd[2]) +{ + assert (fd != nullptr); + + SOCKET listen_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); + if (listen_socket == INVALID_SOCKET) + return false; + + sockaddr_in address; + std::memset(&address, 0, sizeof(address)); + address.sin_family = AF_INET; + address.sin_addr.s_addr = htonl(INADDR_LOOPBACK); + + int ret = bind(listen_socket, + reinterpret_cast(&address), + sizeof(address)); + + if (ret < 0) { + SafeCloseSocket(listen_socket); + return false; + } + + ret = listen(listen_socket, 1); + + if (ret < 0) { + SafeCloseSocket(listen_socket); + return false; + } + + int address_len = sizeof(address); + ret = getsockname(listen_socket, + reinterpret_cast(&address), + &address_len); + + if (ret < 0) { + SafeCloseSocket(listen_socket); + return false; + } + + SOCKET socket0 = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); + if (socket0 == INVALID_SOCKET) { + SafeCloseSocket(listen_socket); + return false; + } + + ret = connect(socket0, + reinterpret_cast(&address), + sizeof(address)); + + if (ret < 0) { + SafeCloseSocket(listen_socket); + SafeCloseSocket(socket0); + return false; + } + + SOCKET socket1 = accept(listen_socket, nullptr, nullptr); + if (socket1 == INVALID_SOCKET) { + SafeCloseSocket(listen_socket); + SafeCloseSocket(socket0); + return false; + } + + SafeCloseSocket(listen_socket); + + u_long non_block = 1; + if (ioctlsocket(socket0, FIONBIO, &non_block) < 0 + || ioctlsocket(socket1, FIONBIO, &non_block) < 0) { + SafeCloseSocket(socket0); + SafeCloseSocket(socket1); + return false; + } + + fd[0] = static_cast(socket0); + fd[1] = static_cast(socket1); + + return true; +} + +#endif diff --git a/src/system/EventPipe.hxx b/src/system/EventPipe.hxx new file mode 100644 index 000000000..86a10b0bb --- /dev/null +++ b/src/system/EventPipe.hxx @@ -0,0 +1,57 @@ +/* + * Copyright (C) 2003-2013 The Music Player Daemon Project + * http://www.musicpd.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#ifndef MPD_EVENT_PIPE_HXX +#define MPD_EVENT_PIPE_HXX + +#include "check.h" + +/** + * A pipe that can be used to trigger an event to the read side. + * + * Errors in the constructor are fatal. + */ +class EventPipe { + int fds[2]; + +public: + EventPipe(); + ~EventPipe(); + + EventPipe(const EventPipe &other) = delete; + EventPipe &operator=(const EventPipe &other) = delete; + + int Get() const { + return fds[0]; + } + + /** + * Checks if Write() was called at least once since the last + * Read() call. + */ + bool Read(); + + /** + * Wakes up the reader. Multiple calls to this function will + * be combined to one wakeup. + */ + void Write(); +}; + +#endif /* MAIN_NOTIFY_H */ -- cgit v1.2.3