reactor.hpp File Reference

Single-threaded event loop with a timer min-heap and a thread-safe mailbox (post/wake via eventfd), over one of two backends chosen at construction: More...

#include "fastmm/net/inplace_callback.hpp"
#include <atomic>
#include <cstddef>
#include <cstdint>
#include <functional>
#include <memory>
#include <mutex>
#include <string_view>
#include <vector>

Go to the source code of this file.

Classes
class	fastmm::net::IoHandler
class	fastmm::net::Reactor

Namespaces
namespace	fastmm
namespace	fastmm::net

Typedefs
using	fastmm::net::TimerId = std::uint64_t

Enumerations
enum class	fastmm::net::IoEvent : std::uint32_t { fastmm::net::None = 0 , fastmm::net::Read = 1 , fastmm::net::Write = 2 , fastmm::net::ReadWrite = 3 }
enum class	fastmm::net::ReactorBackend : std::uint8_t { fastmm::net::Epoll , fastmm::net::IoUring }

Functions
constexpr IoEvent	fastmm::net::operator| (IoEvent a, IoEvent b) noexcept
constexpr bool	fastmm::net::has (IoEvent set, IoEvent flag) noexcept
std::string_view	fastmm::net::to_string (ReactorBackend backend) noexcept
	"epoll" / "io_uring", the spelling of [engine] net_backend.
bool	fastmm::net::parse_reactor_backend (std::string_view text, ReactorBackend &out) noexcept
	Parses "epoll" / "io_uring". Returns false (and leaves out alone) for anything else.

Variables
constexpr TimerId	fastmm::net::kInvalidTimer = 0

Detailed Description

Single-threaded event loop with a timer min-heap and a thread-safe mailbox (post/wake via eventfd), over one of two backends chosen at construction:

ReactorBackend::Epoll edge-triggered epoll (the default) ReactorBackend::IoUring io_uring, one multishot IORING_OP_POLL_ADD per registered fd, timeouts through IORING_ENTER_EXT_ARG, over liburing

All handler callbacks and timers run on the thread that calls run()/run_once(); only wake() and post() may be called from other threads.

Handler contract (both backends): a handler receiving on_readable()/on_writable() must drain the fd until it returns want_read/want_write, otherwise no further event may be delivered. The io_uring backend may report readiness the handler has already consumed; draining until EAGAIN makes that harmless. POLLOUT is only requested while the registration asks for Write.

Descriptor lifetime: call remove() before closing a registered fd. epoll forgets a closed descriptor on its own, but an io_uring poll request holds a reference to the file, so the socket stays open (no FIN, port still bound) until remove() cancels the request. add() of a new socket that reuses the number of a closed but still registered fd cancels the stale registration; this cannot be detected for anonymous-inode descriptors (eventfd, timerfd).