Rebus.UnixFD (rebus v0.3.0)

Closes Unix file descriptors received in D-Bus replies.

A descriptor is represented as the non-negative integer returned by the operating system. Rebus borrows descriptors supplied for an outbound message: it never closes or duplicates them. A descriptor in Rebus.Message.unix_fds was received from a peer and is owned by the process that successfully receives that message. The owner must close it exactly once, or adopt it with its own OS/OTP API.

close/1 consumes an owned descriptor exactly once. Do not call it again: operating systems may reuse descriptor numbers, so a second close could close an unrelated resource. It is suitable for after blocks and does not log descriptor values.

The helpers are available only on Unix systems with OTP's raw-file support. They return {:error, :unsupported} elsewhere.

See Unix file descriptor passing.

Summary

Types

t()

A raw, process-owned Unix file descriptor.

Functions

close(fd)

Closes an owned raw Unix file descriptor.

Types

t()

@type t() :: non_neg_integer()

A raw, process-owned Unix file descriptor.

Functions

close(fd)

@spec close(t()) ::
  :ok | {:error, :close_failed | :invalid_descriptor | :unsupported | term()}

Closes an owned raw Unix file descriptor.

Returns :ok on success or {:error, reason} on failure.

This consumes an adopted descriptor whether it returns :ok or a POSIX error. Treat the number as unusable and never retry: the operating system may already have assigned it to another resource. :invalid_descriptor rejects a value that is not a non-negative integer, :close_failed reports an unexpected close failure, and :unsupported means the platform cannot perform this operation. After :unsupported, the caller still owns the descriptor and must close it with another API.