turnloop

An embeddable event-loop driver for Rust. Your host owns the thread and calls turn() to advance I/O, timers and cross-thread posts. Each turn returns completions, makes at most one OS wait, and runs no user callbacks. There is no runtime thread and no tokio dependency.

Pre-alpha. This workspace contains the Unix driver and runtime-independent PostgreSQL, MySQL, Redis, MongoDB and SMTP protocol engines. APIs can change. Protocol engines consume bytes and produce actions; host transport adapters are still being integrated. The optional local executor drives futures-io streams, sleep and timeout from host turns. Perry is the first intended consumer.

Platform	Current implementation	Validation
macOS arm64	kqueue, TCP/UDP/local IPC, stdio, processes, signals, TTY, timers and shared services	Native contracts, six allocation gates and executor tests
Linux x86_64 / arm64	epoll, pidfd/SIGCHLD, native services, nanosecond waits and timerfd fallback	Cross-checked locally; native CI required
FreeBSD / Apple mobile / Android	Unix backend paths	Best effort; runtime validation pending
Windows x86_64	IOCP, TCP/UDP/named pipes, stdio, processes, console signals, timers and shared services	Native Windows 11 contracts and allocation/executor tests; see `spikes/iocp/WINDOWS_RESULTS.md`
WASI 0.2 / 0.3	Standalone polling / component async spikes	Production adapters and shared contracts pending
Web	Standalone host-callback spike	Production adapter and browser contracts pending

Windows and WASM are required for the first release; standalone spikes are excluded from the publishable workspace. The platform table describes current code, not a completed support promise. HTTP, TLS and WebSocket crates are being worked on separately.

use std::time::Duration;
use turnloop::{Completions, Config, Loop, Timeout, Token};

let mut driver = Loop::new(Config::default())?;
let deadline = driver.now() + Duration::from_millis(2);
driver.timer(deadline, None, Token(42))?;
let mut completions = Completions::default();
driver.turn(Timeout::Until(deadline), &mut completions)?;
// Dispatch completions in the host's own event-loop phase.
# Ok::<(), turnloop::Error>(())

Enable executor for LocalExecutor<B> and its futures-io adapters. Read/write staging and task tables are reserved at construction. Writes are buffered; flush or close before dropping an adapter to confirm underlying completion. AsyncIo::poll_shutdown half-closes a stream without releasing its handle. The crate's rustdoc includes runnable loop and executor examples. See the revision 2 handoff for native ownership, process teardown, platform integration and contract details.

Use the pinned nightly for dependency resolution under the seven-day publication soak. The workspace also builds with stable Rust 1.97.1.

turnloop 0.1.0-alpha.3

turnloop