9cf16857

Restore the claims the ratchets cut from pty and upgrade

a73x 2026-08-31 14:39

Commit message

Restore the claims the ratchets cut from pty and upgrade

`upgrade.zig`'s `attaches` counter pointed at a vague "zoom and unzoom"
proof; the real one is `assert_attach_delta` in `e2e_lib.sh`, which holds
a wall of N tiles to N attaches however far the focus moves. Restores
what SUCCEEDS means and the one-closes-as-another-opens case.

`pty.zig` needed almost nothing — it was never compressed. Two lines:
"Injection's door" now says a child's env comes from nowhere else, and a
trailing flourish goes where the sentence before it already made the claim.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/server/pty.zig

src/server/upgrade.zig

Old		New
@@ -76,15 +76,17 @@ pub const Counters = struct {
76	snapshot_equiv_bytes: u64 = 0,	76	snapshot_equiv_bytes: u64 = 0,
77	/// Every `.attach` this daemon ACCEPTED, cumulative and monotonic.	77	/// Every `.attach` this daemon ACCEPTED, cumulative and monotonic.
78	///	78	///
79	/// A counter where `clients=` is a gauge: the gauge cannot answer "did	79	/// A counter where `clients=` is a gauge, because the gauge cannot answer
80	/// anyone attach since I last looked", because a client that attaches and	80	/// "did anyone attach since I last looked": a client that attaches and
81	/// leaves between two samples is invisible to it. The wall's in-place zoom	81	/// leaves between two samples is invisible to it, and so is one that closes
82	/// is what needs that answered — the proof is that this number did NOT move	82	/// as another opens. `assert_attach_delta` in e2e_lib.sh is what needs the
83	/// across a zoom and an unzoom.	83	/// counter — it holds a wall of N tiles to N attaches however far the focus
		84	/// moves, which is a negative no gauge can witness.
84	///	85	///
85	/// Counted where an attach SUCCEEDS, not where the frame arrives: a refusal	86	/// Counted where an attach SUCCEEDS — a session resolved and the client
86	/// attached nobody. Both arms count, since a socket client's first attach	87	/// seated — not where the frame arrives: a refusal attached nobody. Both
87	/// promotes an observer and every later one arrives established.	88	/// arms count, since a socket client's first attach promotes an observer
		89	/// and every later one, a QUIC first attach included, arrives established.
88	attaches: u64 = 0,	90	attaches: u64 = 0,
89	agent_refused_no_offer: u64 = 0,	91	agent_refused_no_offer: u64 = 0,
90	agent_refused_full: u64 = 0,	92	agent_refused_full: u64 = 0,

Old		New
@@ -29,8 +29,8 @@ pub const Pty = struct {
29	/// The e2e fixture uses this to keep predict stats out of the	29	/// The e2e fixture uses this to keep predict stats out of the
30	/// capture, matching the suite's `.err` sibling convention.	30	/// capture, matching the suite's `.err` sibling convention.
31	stderr_fd: ?std.posix.fd_t = null,	31	stderr_fd: ?std.posix.fd_t = null,
32	/// Set in the child between fork and exec, after TERM. Injection's	32	/// Set in the child between fork and exec, after TERM. A child's env
33	/// door: the daemon's env is the only source of a child's env.	33	/// comes from nowhere else, so this field is where injection enters.
34	env: []const EnvPair = &.{},	34	env: []const EnvPair = &.{},
35	};	35	};
36		36
@@ -252,8 +252,7 @@ test "Pty: deinit is bounded even when the child ignores HUP and TERM" {
252	const elapsed_ms = t.read() / std.time.ns_per_ms;	252	const elapsed_ms = t.read() / std.time.ns_per_ms;
253		253
254	// Returned at all is the headline. The bound is the assertion that can	254	// Returned at all is the headline. The bound is the assertion that can
255	// still fail fast if someone widens the grace period without meaning	255	// still fail fast if someone widens the grace period without meaning to.
256	// to — a shutdown budget is a number you compute, not a mood.
257	try std.testing.expect(elapsed_ms < 3000);	256	try std.testing.expect(elapsed_ms < 3000);
258	// Reaped, not merely abandoned: a deinit that returned while leaving a	257	// Reaped, not merely abandoned: a deinit that returned while leaving a
259	// zombie would satisfy the clock and leak the process.	258	// zombie would satisfy the clock and leak the process.