diff options
Diffstat (limited to 'src/event/PollGroupWinSelect.cxx')
| -rw-r--r-- | src/event/PollGroupWinSelect.cxx | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/src/event/PollGroupWinSelect.cxx b/src/event/PollGroupWinSelect.cxx new file mode 100644 index 000000000..1050ffa8a --- /dev/null +++ b/src/event/PollGroupWinSelect.cxx @@ -0,0 +1,158 @@ +/* + * 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 |