Module link 

Whether an SSH connection is up, as its Remotes row and the overlay on its panes show it (status), kept true to the connection itself.

On macOS and Linux every ssh srv runs on a connection shares one connection with the others (ControlMaster, ssh.rs), and that shared connection is the truth: it exists only once the user has logged in, and ssh -O check answers then and only then. A pane’s ssh starting is only connecting (it may be waiting at a password prompt), and the connection can outlive its last pane (ControlPersist) or end under it. So while a connection is in use a watcher asks it, every half second while connecting and every 15 s once up, and moves the status when the answer changes: connected once logged in, disconnected once it is gone, whenever that is.

Where ssh can’t share connections (Windows) there is nothing to ask: a running ssh counts as connected, as it always did.

The user’s Disconnect (disconnect) closes the shared connection, and the connection stays down until something logs in to it again: durable panes on it wait for the user (held) instead of logging back in.

Structs

Step 🔒

What the watcher does with one answer.

Constants

WHILE_CONNECTING 🔒

How soon the watcher asks again while a login may be under way.

WHILE_UP 🔒

How soon it asks again while the connection is up.

Statics

BROKER 🔒

Functions

broker 🔒

disconnect

The user’s Disconnect: close connection’s shared connection (every session on it ends) and keep it down until something logs in again.

disconnected_note

The line a pane on connection shows when the user’s Disconnect ended it.

ended 🔒

settle: a clean last end leaves the connection disconnected, rather than to the watcher. A connection the user disconnected ended because they asked: not an error.

held

Whether the user disconnected connection and nothing has logged in to it since: a durable pane that lost it waits for the user instead of reconnecting.

held_set 🔒

hold 🔒

init

Where status changes are published, set once at startup. Until then (and in unit tests) a status is recorded but not published.

login

Log in over connection (attempt: a command over it), holding the connection open meanwhile like a pane, so its status is connecting while the user answers a prompt, connected once the command succeeded, and the failure if it didn’t.

login_ended 🔒

A login’s own end: connected if it worked (said first, and never settled by its end, since it is the news), the failure if it didn’t.

pane_ended

A pane’s process on connection ended; error when it had no connection or lost it.

pane_started

A pane’s process on connection started (a plain pane’s ssh, a durable pane’s attach). logged_in: it is known to be a live login already (a durable pane’s helper answered); otherwise it is connecting until the shared connection answers.

release 🔒

run 🔒

shared 🔒

Whether ssh shares connections here, so there is one to ask.

started 🔒

step 🔒

The watcher’s decision, from the shared connection’s answer (up; None when it couldn’t be asked), the connection’s status and open panes, and whether the user disconnected it (held): every login releases that first, so a held connection’s “up” is an answer from before the Disconnect closed it, and is taken as down.

used

Something used connection successfully (a command over it, such as a Files pane’s helper starting): it is up, and where ssh shares connections its status follows the shared connection from here.

used_with 🔒

watch 🔒

Make sure connection is watched, and have its watcher ask now.

watches 🔒