Files
mpd/src/system/EventPipe.cxx
2024-01-13 22:31:16 +01:00

88 lines
2.0 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#include "EventPipe.hxx"
#include "io/FileDescriptor.hxx"
#include "system/Error.hxx"
#include <cassert>
#ifdef _WIN32
#include "net/IPv4Address.hxx"
#include "net/StaticSocketAddress.hxx"
#include "net/UniqueSocketDescriptor.hxx"
#include "net/SocketError.hxx"
#endif
#ifdef _WIN32
static void PoorSocketPair(UniqueSocketDescriptor &socket0,
UniqueSocketDescriptor &socket01);
#endif
EventPipe::EventPipe()
{
#ifdef _WIN32
PoorSocketPair(r, w);
#else
if (!UniqueFileDescriptor::CreatePipeNonBlock(r, w))
throw MakeErrno("pipe() has failed");
#endif
}
EventPipe::~EventPipe() noexcept = default;
bool
EventPipe::Read() noexcept
{
assert(r.IsDefined());
assert(w.IsDefined());
std::byte buffer[256];
return r.Read(buffer) > 0;
}
void
EventPipe::Write() noexcept
{
assert(r.IsDefined());
assert(w.IsDefined());
static constexpr std::byte buffer[1]{};
(void)w.Write(buffer);
}
#ifdef _WIN32
/* Our poor man's socketpair() implementation
* Due to limited protocol/address family support
* it's better to keep this as a private implementation detail of EventPipe
* rather than wide-available API.
*/
static void
PoorSocketPair(UniqueSocketDescriptor &socket0, UniqueSocketDescriptor &socket1)
{
UniqueSocketDescriptor listen_socket;
if (!listen_socket.Create(AF_INET, SOCK_STREAM, IPPROTO_TCP))
throw MakeSocketError("Failed to create socket");
if (!listen_socket.Bind(IPv4Address(IPv4Address::Loopback(), 0)))
throw MakeSocketError("Failed to create socket");
if (!listen_socket.Listen(1))
throw MakeSocketError("Failed to listen on socket");
if (!socket0.Create(AF_INET, SOCK_STREAM, IPPROTO_TCP))
throw MakeSocketError("Failed to create socket");
if (!socket0.Connect(listen_socket.GetLocalAddress()))
throw MakeSocketError("Failed to connect socket");
socket0.SetNonBlocking();
socket1 = listen_socket.AcceptNonBlock();
if (!socket1.IsDefined())
throw MakeSocketError("Failed to accept connection");
}
#endif