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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.
*/
#ifndef MPD_MULTI_SOCKET_MONITOR_HXX
#define MPD_MULTI_SOCKET_MONITOR_HXX
#include "check.h"
#include "Compiler.h"
#ifdef USE_EPOLL
#include "IdleMonitor.hxx"
#include "TimeoutMonitor.hxx"
#include "SocketMonitor.hxx"
#else
#include <glib.h>
#endif
#include <forward_list>
#include <assert.h>
#include <stdint.h>
#ifdef WIN32
/* ERROR is a WIN32 macro that poisons our namespace; this is a kludge
to allow us to use it anyway */
#ifdef ERROR
#undef ERROR
#endif
#endif
class EventLoop;
/**
* Similar to #SocketMonitor, but monitors multiple sockets. To use
* it, implement the methods PrepareSockets() and DispatchSockets().
* In PrepareSockets(), use UpdateSocketList() and AddSocket().
* DispatchSockets() will be called if at least one socket is ready.
*/
class MultiSocketMonitor
#ifdef USE_EPOLL
: private IdleMonitor, private TimeoutMonitor
#endif
{
#ifdef USE_EPOLL
class SingleFD final : public SocketMonitor {
MultiSocketMonitor &multi;
unsigned revents;
public:
SingleFD(MultiSocketMonitor &_multi, int _fd, unsigned events)
:SocketMonitor(_fd, _multi.GetEventLoop()),
multi(_multi), revents(0) {
Schedule(events);
}
int GetFD() const {
return SocketMonitor::Get();
}
unsigned GetEvents() const {
return SocketMonitor::GetScheduledFlags();
}
void SetEvents(unsigned _events) {
revents &= _events;
SocketMonitor::Schedule(_events);
}
unsigned GetReturnedEvents() const {
return revents;
}
void ClearReturnedEvents() {
revents = 0;
}
protected:
virtual bool OnSocketReady(unsigned flags) override {
revents = flags;
multi.SetReady();
return true;
}
};
friend class SingleFD;
bool ready, refresh;
#else
struct Source {
GSource base;
MultiSocketMonitor *monitor;
};
struct SingleFD {
GPollFD pfd;
constexpr SingleFD(gcc_unused MultiSocketMonitor &m,
int fd, unsigned events)
:pfd{fd, gushort(events), 0} {}
constexpr int GetFD() const {
return pfd.fd;
}
constexpr unsigned GetEvents() const {
return pfd.events;
}
constexpr unsigned GetReturnedEvents() const {
return pfd.revents;
}
void SetEvents(unsigned _events) {
pfd.events = _events;
}
};
EventLoop &loop;
Source *source;
uint64_t absolute_timeout_us;
#endif
std::forward_list<SingleFD> fds;
public:
#ifdef USE_EPOLL
static constexpr unsigned READ = SocketMonitor::READ;
static constexpr unsigned WRITE = SocketMonitor::WRITE;
static constexpr unsigned ERROR = SocketMonitor::ERROR;
static constexpr unsigned HANGUP = SocketMonitor::HANGUP;
#else
static constexpr unsigned READ = G_IO_IN;
static constexpr unsigned WRITE = G_IO_OUT;
static constexpr unsigned ERROR = G_IO_ERR;
static constexpr unsigned HANGUP = G_IO_HUP;
#endif
MultiSocketMonitor(EventLoop &_loop);
~MultiSocketMonitor();
#ifdef USE_EPOLL
using IdleMonitor::GetEventLoop;
#else
EventLoop &GetEventLoop() {
return loop;
}
#endif
public:
#ifndef USE_EPOLL
gcc_pure
uint64_t GetTime() const {
return g_source_get_time(&source->base);
}
#endif
void InvalidateSockets() {
#ifdef USE_EPOLL
refresh = true;
IdleMonitor::Schedule();
#else
/* no-op because GLib always calls the GSource's
"prepare" method before each poll() anyway */
#endif
}
void AddSocket(int fd, unsigned events) {
fds.emplace_front(*this, fd, events);
#ifndef USE_EPOLL
g_source_add_poll(&source->base, &fds.front().pfd);
#endif
}
template<typename E>
void UpdateSocketList(E &&e) {
for (auto prev = fds.before_begin(), end = fds.end(),
i = std::next(prev);
i != end; i = std::next(prev)) {
assert(i->GetEvents() != 0);
unsigned events = e(i->GetFD());
if (events != 0) {
i->SetEvents(events);
prev = i;
} else {
#ifdef USE_EPOLL
i->Steal();
#else
g_source_remove_poll(&source->base, &i->pfd);
#endif
fds.erase_after(prev);
}
}
}
protected:
/**
* @return timeout [ms] or -1 for no timeout
*/
virtual int PrepareSockets() = 0;
virtual void DispatchSockets() = 0;
#ifdef USE_EPOLL
private:
void SetReady() {
ready = true;
IdleMonitor::Schedule();
}
void Prepare();
virtual void OnTimeout() final {
SetReady();
IdleMonitor::Schedule();
}
virtual void OnIdle() final;
#else
public:
/* GSource callbacks */
static gboolean Prepare(GSource *source, gint *timeout_r);
static gboolean Check(GSource *source);
static gboolean Dispatch(GSource *source, GSourceFunc callback,
gpointer user_data);
private:
bool Prepare(gint *timeout_r);
bool Check() const;
void Dispatch() {
DispatchSockets();
}
#endif
};
#endif
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