D371 - Files and sockets share one descriptor table

Status: decided Date: 2026-08-29

Files and sockets are entries in one descriptor table, so read, write and close take either. A socket is pending until listen or connect makes it a host object, remembering what bind was told. setsockopt succeeds and applies nothing, and says so in the knowledge file. Socket addresses follow the FreeBSD layout with a length byte first.

Why: a guest has one numbering space, and two tables make a descriptor mean different things to different calls. The host creates a listener in one step, so binding early would hold the port twice. Failing setsockopt stops a correct server before bind, while an unverifiable option mapping changes socket behaviour silently. The address layout was read from the headers, not recalled.

Rejected:

• Separate file and socket tables: two numbering spaces.
• Binding at bind: the port is held twice.
• Refusing setsockopt: ends every server before it listens.