0.10.0

Fix accept loop spinning on persistent errors

Previously, when TCPListener's accept loop encountered a non-EWOULDBLOCK error (such as running out of file descriptors), it would retry immediately in a tight loop. Since persistent errors like EMFILE never resolve on their own, this caused the listener to spin indefinitely, consuming CPU without making progress.

The accept loop now exits on any error, letting the ASIO event system re-notify the listener. This gives other actors a chance to run and potentially free resources before the next accept attempt.

Fix read loop not yielding after byte threshold

The POSIX read loop in TCPConnection was missing a return after scheduling a deferred _read_again when the byte threshold was reached. This meant the loop continued reading from the socket in the same behavior call indefinitely under sustained load, preventing per-actor GC from running (GC only runs between behavior invocations) and queuing redundant _read_again messages. The read loop now correctly exits after reaching the threshold, allowing GC and other actors to run before resuming.

Add IPv4-only and IPv6-only support

Lori now supports restricting connections to a specific IP protocol version. Client constructors (TCPConnection.client, TCPConnection.ssl_client) and TCPListener accept an optional ip_version parameter that defaults to DualStack (existing behavior).

Pass IP4 to restrict to IPv4 only or IP6 for IPv6 only:

// IPv4-only listener
_tcp_listener = TCPListener(listen_auth, "127.0.0.1", "7669", this
  where ip_version = IP4)

// IPv4-only client
_tcp_connection = TCPConnection.client(auth, "127.0.0.1", "7669", "", this,
  this where ip_version = IP4)

// IPv6-only client
_tcp_connection = TCPConnection.client(auth, "::1", "7669", "", this, this
  where ip_version = IP6)

// SSL client with IPv4 only
_tcp_connection = TCPConnection.ssl_client(auth, sslctx, "127.0.0.1", "7669",
  "", this, this where ip_version = IP4)

Server-side constructors (server, ssl_server) don't need this parameter — they accept an already-connected fd whose protocol version was determined by the listener.

Change TCPListener parameter order

The ip_version parameter on TCPListener.create now comes before limit. Since ip_version is a hard requirement in many environments while limit is rarely set, the more commonly used parameter should come first.

If you were passing limit positionally:

// Before
_tcp_listener = TCPListener(listen_auth, host, port, this, 100)

// After
match MakeMaxSpawn(100)
| let limit: MaxSpawn =>
  _tcp_listener = TCPListener(listen_auth, host, port, this where limit = limit)
end

Change MaxSpawn to a constrained type

MaxSpawn is now a constrained type that rejects invalid values at construction time. Previously it was a bare (U32 | None) type alias, which meant a limit of 0 would silently create a listener that refused every connection. The new type guarantees the value is at least 1.

// Before — bare U32
_tcp_listener = TCPListener(listen_auth, host, port, this where limit = 100)

// After — construct via MakeMaxSpawn
match MakeMaxSpawn(100)
| let limit: MaxSpawn =>
  _tcp_listener = TCPListener(listen_auth, host, port, this where limit = limit)
end

Change default connection limit to 100,000

Listeners without an explicit limit parameter now cap at 100,000 concurrent connections (DefaultMaxSpawn) rather than having no limit. This is a safer default for production systems. Pass None to restore the old unlimited behavior:

// New default — 100,000 connections (no code change needed)
_tcp_listener = TCPListener(listen_auth, host, port, this)

// Restore old unlimited behavior
_tcp_listener = TCPListener(listen_auth, host, port, this where limit = None)

[0.10.0] - 2026-03-03

Fixed

• Fix accept loop spinning on persistent errors (PR #208)
• Fix read loop not yielding after byte threshold (PR #209)

Added

• Add IPv4-only and IPv6-only support (PR #205)

Changed

• Change TCPListener parameter order (PR #205)
• Change MaxSpawn to a constrained type (PR #210)
• Change default connection limit to 100,000 (PR #210)