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/*
* 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 "WakeFD.hxx"
#include "fd_util.h"
#include "gcc.h"
#include <unistd.h>
#ifdef WIN32
#include <ws2tcpip.h>
#include <winsock2.h>
#include <cstring> /* for memset() */
#endif
#ifdef HAVE_EVENTFD
#include <sys/eventfd.h>
#endif
#ifdef WIN32
static bool PoorSocketPair(int fd[2]);
#endif
bool
WakeFD::Create()
{
assert(fds[0] == -1);
assert(fds[1] == -1);
#ifdef WIN32
return PoorSocketPair(fds);
#else
#ifdef HAVE_EVENTFD
fds[0] = eventfd_cloexec_nonblock(0, 0);
if (fds[0] >= 0) {
fds[1] = -2;
return true;
}
#endif
return pipe_cloexec_nonblock(fds) >= 0;
#endif
}
void
WakeFD::Destroy()
{
#ifdef WIN32
closesocket(fds[0]);
closesocket(fds[1]);
#else
close(fds[0]);
#ifdef HAVE_EVENTFD
if (!IsEventFD())
#endif
close(fds[1]);
#endif
#ifndef NDEBUG
fds[0] = -1;
fds[1] = -1;
#endif
}
bool
WakeFD::Read()
{
assert(fds[0] >= 0);
#ifdef WIN32
assert(fds[1] >= 0);
char buffer[256];
return recv(fds[0], buffer, sizeof(buffer), 0) > 0;
#else
#ifdef HAVE_EVENTFD
if (IsEventFD()) {
eventfd_t value;
return read(fds[0], &value,
sizeof(value)) == (ssize_t)sizeof(value);
}
#endif
assert(fds[1] >= 0);
char buffer[256];
return read(fds[0], buffer, sizeof(buffer)) > 0;
#endif
}
void
WakeFD::Write()
{
assert(fds[0] >= 0);
#ifdef WIN32
assert(fds[1] >= 0);
send(fds[1], "", 1, 0);
#else
#ifdef HAVE_EVENTFD
if (IsEventFD()) {
static constexpr eventfd_t value = 1;
gcc_unused ssize_t nbytes =
write(fds[0], &value, sizeof(value));
return;
}
#endif
assert(fds[1] >= 0);
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 WakeFD
* 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<sockaddr*>(&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<sockaddr*>(&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<sockaddr*>(&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<int>(socket0);
fd[1] = static_cast<int>(socket1);
return true;
}
#endif
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