feat(fast_io): IOCP socket I/O via WSARecv/WSASend (#1928)#3539
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Adds an IOCP-backed async socket reader/writer that mirrors the io_uring socket surface and dispatches completions through the shared CompletionPump from #1897. Each WSARecv/WSASend issues an OVERLAPPED operation; synchronous completions and WSA_IO_PENDING paths both wait on a oneshot handler registered with the pump, so file I/O and socket I/O share a single drain thread. Mirrors upstream rsync's socket I/O semantics: - recv treats graceful peer close (WSAEDISCON, WSAESHUTDOWN, WSAENETRESET, WSAECONNRESET, WSAECONNABORTED) and STATUS_END_OF_FILE as Ok(0), matching safe_read breaking on n == 0 (target/interop/upstream-src/rsync-3.4.1/io.c:276). - send maps WSAESHUTDOWN/WSAECONNRESET/WSAECONNABORTED to BrokenPipe and returns short counts so the caller's loop re-issues, matching safe_write's partial-write retry (io.c:316-336). Files: - crates/fast_io/src/iocp/socket.rs (new): IocpSocketReader, IocpSocketWriter, SharedPump alias, six tests covering localhost TCP roundtrip, partial 64KB send accounting, peer-shutdown EOF, empty-buffer fast paths, and completion-key override. - crates/fast_io/src/iocp/mod.rs: pub mod socket; (single line) - crates/fast_io/src/iocp_stub.rs: matching stub module so the workspace cross-compiles on Linux and macOS, all methods returning io::ErrorKind::Unsupported. - crates/fast_io/Cargo.toml: add Win32_Networking_WinSock to the windows-sys feature list for WSARecv/WSASend bindings. Cross-platform compile preserved: the real implementation is gated behind cfg(all(target_os = "windows", feature = "iocp")) at the fast_io::iocp module level; non-Windows builds fall through to the stub.
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* feat(fast_io): IOCP socket I/O via WSARecv/WSASend (#1928) Adds an IOCP-backed async socket reader/writer that mirrors the io_uring socket surface and dispatches completions through the shared CompletionPump from #1897. Each WSARecv/WSASend issues an OVERLAPPED operation; synchronous completions and WSA_IO_PENDING paths both wait on a oneshot handler registered with the pump, so file I/O and socket I/O share a single drain thread. Mirrors upstream rsync's socket I/O semantics: - recv treats graceful peer close (WSAEDISCON, WSAESHUTDOWN, WSAENETRESET, WSAECONNRESET, WSAECONNABORTED) and STATUS_END_OF_FILE as Ok(0), matching safe_read breaking on n == 0 (target/interop/upstream-src/rsync-3.4.1/io.c:276). - send maps WSAESHUTDOWN/WSAECONNRESET/WSAECONNABORTED to BrokenPipe and returns short counts so the caller's loop re-issues, matching safe_write's partial-write retry (io.c:316-336). Files: - crates/fast_io/src/iocp/socket.rs (new): IocpSocketReader, IocpSocketWriter, SharedPump alias, six tests covering localhost TCP roundtrip, partial 64KB send accounting, peer-shutdown EOF, empty-buffer fast paths, and completion-key override. - crates/fast_io/src/iocp/mod.rs: pub mod socket; (single line) - crates/fast_io/src/iocp_stub.rs: matching stub module so the workspace cross-compiles on Linux and macOS, all methods returning io::ErrorKind::Unsupported. - crates/fast_io/Cargo.toml: add Win32_Networking_WinSock to the windows-sys feature list for WSARecv/WSASend bindings. Cross-platform compile preserved: the real implementation is gated behind cfg(all(target_os = "windows", feature = "iocp")) at the fast_io::iocp module level; non-Windows builds fall through to the stub. * style(transport): cargo fmt
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Summary
Adds IOCP-backed async socket I/O for issue #1928, completing the Windows-side counterpart to the io_uring socket reader/writer. Each WSARecv/WSASend issues an OVERLAPPED Winsock operation that completes through the shared
CompletionPumpfrom #1897, so file I/O and socket I/O share a single drain thread.IocpSocketReader/IocpSocketWriterincrates/fast_io/src/iocp/socket.rswith six tests (localhost TCP roundtrip, 64 KB partial-send accounting, peer-shutdown EOF, empty-buffer fast paths, completion-key override).SharedPump = Arc<CompletionPump>lets multiple sockets and the existing IOCP file readers/writers share one pump.iocp_stub.rsexposes the same public surface so Linux and macOS continue to build.Win32_Networking_WinSockadded to thewindows-sysfeature list for the WSARecv/WSASend bindings.Integration with the IOCP pump (#1897)
The pump already exposes
register(overlapped_ptr, handler)/unregister/associate_handle/pending_ops. Sockets reuse those primitives unchanged:socket.rsallocates aBox<OVERLAPPED>so the kernel-visible pointer is stable, registers a oneshot handler, callsWSARecv/WSASend, and waits on the channel for the completion. Synchronous completions still flow through the pump for registry consistency.Upstream parity
Recv mirrors
safe_read(target/interop/upstream-src/rsync-3.4.1/io.c:239,:276): graceful peer close paths (WSAEDISCON,WSAESHUTDOWN,WSAENETRESET,WSAECONNRESET,WSAECONNABORTED) andSTATUS_END_OF_FILEcollapse toOk(0). Send mirrorssafe_write(io.c:312,:316-336): short counts are returned so the caller's loop re-issues; broken-pipe errors map toio::ErrorKind::BrokenPipe.Files added / modified
crates/fast_io/src/iocp/socket.rscrates/fast_io/src/iocp/mod.rs(singlepub mod socket;line, no other changes)crates/fast_io/src/iocp_stub.rs(parallelsocketstub module)crates/fast_io/Cargo.toml(Win32_Networking_WinSockfeature added)Cross-platform compile preserved
Real implementation is gated behind
cfg(all(target_os = \"windows\", feature = \"iocp\"))at thefast_io::iocpmodule level (inlib.rs); non-Windows builds fall through to the stub which returnsio::ErrorKind::Unsupportedfrom every constructor and method.Test plan
fast_io::iocp::socket::tests.