Module exec 

Streaming exec engine: a running command in a sailbox with live output.

ExecProcess::start opens the worker proxy’s server-streaming StreamSailboxExec RPC. The first frame is Started (carrying the durable exec_request_id); chunk frames carry live stdout/stderr; a terminal Exit frame carries the result. The command is detached on the server, so dropping the handle never kills it.

A background pump task drains the stream into two drop-oldest ring buffers that synchronous readers (StreamReader) pull from. If the stream breaks mid-run, the pump reconnects with the same idempotency key and the per-stream seqs it last saw, so the guest replays only the unseen tail. Only when the stream cannot be resumed does ExecProcess::wait fall back to polling WaitSailboxExec for the authoritative buffered result. Stdin rides a separate offset-idempotent unary RPC, independent of the output stream.

Structs

AsyncStreamReader

An async cursor over one live output stream, the awaiting counterpart of StreamReader. AsyncStreamReader::next yields the next chunk without parking a runtime thread, so many streams can be read on one event loop.

ExecOptions

Optional settings for Sailbox::exec and Sailbox::exec_shell. Default runs a plain foreground command (no pty, no stdin, no timeout) and retries transient failures against a waking or migrating sailbox for 30 seconds (see retry_timeout).

ExecProcess

A handle to a running command. Drop or ExecProcess::close releases the stream without killing the command.

ExecResult

The buffered result of a finished exec.

StreamReader

A cursor over one live output stream. StreamReader::next blocks up to a timeout for the next chunk.

Enums

CancelSignal

Which signal to send when cancelling a running exec.

OutputStream

Which output stream a chunk or reader belongs to.

ReadStep

One step of reading a live output stream.

RetryBudget

How long to keep retrying transient RPCs against a waking or migrating sailbox before giving up.

Constants

EXEC_TRANSIENT_RETRY_TIMEOUT_SECONDS

Default budget for transient-RPC retries against a waking/migrating sailbox; the default value of ExecOptions::retry_timeout.

Functions

shell_argv

Build the argv that runs command via /bin/sh -lc, applying the cwd/background shell conveniences from options and validating their combinations. This is the single implementation behind every SDK’s string-command exec.