/*
* 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_WINSELECT
#include "PollGroupWinSelect.hxx"
constexpr int EVENT_READ = 0;
constexpr int EVENT_WRITE = 1;
static inline bool HasEvent(unsigned events, int event_id)
{
return (events & (1 << event_id)) != 0;
}
bool PollGroupWinSelect::CanModify(PollGroupWinSelect::Item &item,
unsigned events, int event_id)
{
if (item.index[event_id] < 0 && HasEvent(events, event_id))
return !event_set[event_id].IsFull();
return true;
}
void PollGroupWinSelect::Modify(PollGroupWinSelect::Item &item, int fd,
unsigned events, int event_id)
{
int index = item.index[event_id];
auto &set = event_set[event_id];
if (index < 0 && HasEvent(events, event_id))
item.index[event_id] = set.Add(fd);
else if (index >= 0 && !HasEvent(events, event_id)) {
if (index != set.Size() - 1) {
set.MoveToEnd(index);
items[set[index]].index[event_id] = index;
}
set.RemoveLast();
item.index[event_id] = -1;
}
}
bool PollGroupWinSelect::Add(int fd, unsigned events, void *obj)
{
assert(items.find(fd) == items.end());
auto &item = items[fd];
item.index[EVENT_READ] = -1;
item.index[EVENT_WRITE] = -1;
item.obj = obj;
item.events = 0;
if (!CanModify(item, events, EVENT_READ)) {
items.erase(fd);
return false;
}
if (!CanModify(item, events, EVENT_WRITE)) {
items.erase(fd);
return false;
}
Modify(item, fd, events, EVENT_READ);
Modify(item, fd, events, EVENT_WRITE);
return true;
}
bool PollGroupWinSelect::Modify(int fd, unsigned events, void *obj)
{
auto item_iter = items.find(fd);
assert(item_iter != items.end());
auto &item = item_iter->second;
if (!CanModify(item, events, EVENT_READ))
return false;
if (!CanModify(item, events, EVENT_WRITE))
return false;
item.obj = obj;
Modify(item, fd, events, EVENT_READ);
Modify(item, fd, events, EVENT_WRITE);
return true;
}
bool PollGroupWinSelect::Remove(int fd)
{
auto item_iter = items.find(fd);
assert(item_iter != items.end());
auto &item = item_iter->second;
Modify(item, fd, 0, EVENT_READ);
Modify(item, fd, 0, EVENT_WRITE);
items.erase(item_iter);
return true;
}
void PollGroupWinSelect::ReadEvents(PollResultGeneric &result, int timeout_ms)
{
bool use_sleep = event_set[EVENT_READ].IsEmpty() &&
event_set[EVENT_WRITE].IsEmpty();
if (use_sleep) {
Sleep(timeout_ms < 0 ? INFINITE : (DWORD) timeout_ms);
return;
}
SocketSet read_set(event_set[EVENT_READ]);
SocketSet write_set(event_set[EVENT_WRITE]);
SocketSet except_set(event_set[EVENT_WRITE]);
timeval tv;
if (timeout_ms >= 0) {
tv.tv_sec = timeout_ms / 1000;
tv.tv_usec = (timeout_ms % 1000) * 1000;
}
int ret = select(0,
read_set.IsEmpty() ? nullptr : read_set.GetPtr(),
write_set.IsEmpty() ? nullptr : write_set.GetPtr(),
except_set.IsEmpty() ? nullptr : except_set.GetPtr(),
timeout_ms < 0 ? nullptr : &tv);
if (ret == 0 || ret == SOCKET_ERROR)
return;
for (int i = 0; i < read_set.Size(); ++i)
items[read_set[i]].events |= READ;
for (int i = 0; i < write_set.Size(); ++i)
items[write_set[i]].events |= WRITE;
for (int i = 0; i < except_set.Size(); ++i)
items[except_set[i]].events |= WRITE;
for (auto i = items.begin(); i != items.end(); ++i)
if (i->second.events != 0) {
result.Add(i->second.events, i->second.obj);
i->second.events = 0;
}
}
#endif
