mpd/src/event/EpollBackend.hxx
2023-03-21 11:00:41 +01:00

67 lines
1.3 KiB
C++

// SPDX-License-Identifier: BSD-2-Clause
// author: Max Kellermann <max.kellermann@gmail.com>
#pragma once
#include "system/EpollFD.hxx"
#include <array>
#include <algorithm>
class EpollBackendResult
{
friend class EpollBackend;
std::array<epoll_event, 16> events;
size_t n_events = 0;
public:
size_t GetSize() const noexcept {
return n_events;
}
unsigned GetEvents(size_t i) const noexcept {
return events[i].events;
}
void *GetObject(size_t i) const noexcept {
return events[i].data.ptr;
}
};
class EpollBackend
{
EpollFD epoll;
EpollBackend(EpollBackend &) = delete;
EpollBackend &operator=(EpollBackend &) = delete;
public:
EpollBackend() = default;
auto ReadEvents(int timeout_ms) noexcept {
EpollBackendResult result;
int ret = epoll.Wait(result.events.data(), result.events.size(),
timeout_ms);
result.n_events = std::max(0, ret);
return result;
}
bool Add(int fd, unsigned events, void *obj) noexcept {
return epoll.Add(fd, events, obj);
}
bool Modify(int fd, unsigned events, void *obj) noexcept {
return epoll.Modify(fd, events, obj);
}
bool Remove(int fd) noexcept {
return epoll.Remove(fd);
}
bool Abandon([[maybe_unused]] int fd) noexcept {
// Nothing to do in this implementation.
// Closed descriptors are automatically unregistered.
return true;
}
};