From cb4c612461c394d327927d2b874372e39e0f4b46 Mon Sep 17 00:00:00 2001 From: Steve Dudenhoeffer Date: Tue, 30 Jun 2026 11:32:46 -0400 Subject: [PATCH] fix(run): address gadfly review of the critic-deadline PR MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit All 11 findings were real (3 clusters): - Failsafe ceiling could pre-empt the critic's backstop (e9c9483f, 9109317b, d5a9bf0d, 76ad171e): CriticAbsoluteMax was 6h, but the host's backstop (MaxRuntime × multiplier, or its own absolute max) can reach 6h+, so the ceiling fired first and reintroduced a premature hard cap. Now CriticAbsoluteMax is a 24h RUNAWAY guard set far beyond any realistic backstop (the host clamps its own backstop to a much smaller absolute max, e.g. mort's 6h convar), so it never pre-empts a healthy supervised run. Comments corrected. - nil Monitor handle lost the MaxRuntime cap (df016a6f, 9dd42827): a critic-enabled run whose host Monitor returned no handle had no deadline-watch and was bounded only by the generous ceiling. Added an unsupervised-run failsafe that re-wraps runCtx to the nominal MaxRuntime when the critic is enabled but didn't arm. New test TestCriticOwnsDeadline_NilHandleFallsBackToMaxRuntime. - CriticSoftTimeout vestigial / dead fallback (f7764919, 9805bebe, 6864086f, b2b11721): the soft trigger is now always the resolved MaxRuntime (> 0), so the CriticSoftTimeout field + its startCritic fallback were unreachable. Removed the field entirely; the remaining 90s floor is documented as defensive-only. - DRY (f30ce827): extracted e.criticOwnsDeadline(ra), now the single predicate used by both Run and startCritic so they can't drift. Co-Authored-By: Claude Opus 4.8 (1M context) Claude-Session: https://claude.ai/code/session_01Jo75sqmeVPgFUWZQBn179X --- run/critic.go | 19 ++++++++---- run/critic_deadline_test.go | 28 +++++++++++++++-- run/critic_test.go | 4 +-- run/executor.go | 61 +++++++++++++++++++++++++------------ 4 files changed, 81 insertions(+), 31 deletions(-) diff --git a/run/critic.go b/run/critic.go index 83fb984..d5eafdd 100644 --- a/run/critic.go +++ b/run/critic.go @@ -22,6 +22,14 @@ type criticBinding struct { h CriticHandle } +// criticOwnsDeadline reports whether a critic is configured AND this run enables +// it — the single predicate that decides the two-tier-timeout path. Used by BOTH +// Run (to choose the generous runaway ceiling over the literal MaxRuntime cap) and +// startCritic (the arm/no-op gate), so the two can never drift. +func (e *Executor) criticOwnsDeadline(ra RunnableAgent) bool { + return e.cfg.Ports.Critic != nil && ra.Critic.Enabled +} + // startCritic begins critic monitoring for this run when one is configured and // the agent enables it. It launches a goroutine that cancels runCtx (via // cancelCause) the moment the critic's hard deadline passes — the critic may @@ -35,18 +43,17 @@ type criticBinding struct { // softTrigger is the run's resolved MaxRuntime: for a critic-owned run MaxRuntime // is the soft wake (mort's two-tier semantics — the critic first reviews once the // run exceeds its nominal budget, and its backstop = softTrigger × multiplier). -// It falls back to the configured CriticSoftTimeout when the run set no MaxRuntime. +// The caller (Run) always passes the resolved MaxRuntime, which withFallbacks +// guarantees is > 0; the 90s floor below is purely a defensive guard for a +// hypothetical caller that passes a non-positive value. func (e *Executor) startCritic(runCtx context.Context, cancelCause context.CancelCauseFunc, ra RunnableAgent, info RunInfo, softTrigger time.Duration) (*criticBinding, func()) { noop := func() {} - if e.cfg.Ports.Critic == nil || !ra.Critic.Enabled { + if !e.criticOwnsDeadline(ra) { return nil, noop } soft := softTrigger if soft <= 0 { - soft = e.cfg.Defaults.CriticSoftTimeout - } - if soft <= 0 { - soft = 90 * time.Second // defensive: withFallbacks normally guarantees >0 + soft = 90 * time.Second // defensive only; the sole caller passes MaxRuntime (>0) } h := e.cfg.Ports.Critic.Monitor(runCtx, info, soft) if h == nil { diff --git a/run/critic_deadline_test.go b/run/critic_deadline_test.go index 30ddc16..8d78c8b 100644 --- a/run/critic_deadline_test.go +++ b/run/critic_deadline_test.go @@ -106,7 +106,7 @@ func (c *capturingCritic) Monitor(_ context.Context, _ run.RunInfo, soft time.Du // TestCriticSoftTriggerIsMaxRuntime: the soft trigger handed to the host critic is // the run's resolved MaxRuntime (mort's two-tier model — the critic first wakes once -// the run exceeds its nominal budget), NOT the global Defaults.CriticSoftTimeout. +// the run exceeds its nominal budget), not some global/default value. func TestCriticSoftTriggerIsMaxRuntime(t *testing.T) { fp := fake.New("fake") fp.Enqueue("m", fake.Reply("done")) @@ -116,7 +116,6 @@ func TestCriticSoftTriggerIsMaxRuntime(t *testing.T) { Registry: tool.NewRegistry(), Models: func(ctx context.Context, _ string) (context.Context, llm.Model, error) { return ctx, m, nil }, Ports: run.Ports{Critic: cc}, - Defaults: run.Defaults{CriticSoftTimeout: 90 * time.Second}, // distinct from MaxRuntime below }) const wantSoft = 7 * time.Minute ex.Run(context.Background(), @@ -126,6 +125,29 @@ func TestCriticSoftTriggerIsMaxRuntime(t *testing.T) { got := cc.soft cc.mu.Unlock() if got != wantSoft { - t.Errorf("soft trigger = %v, want the agent's MaxRuntime %v (not Defaults.CriticSoftTimeout)", got, wantSoft) + t.Errorf("soft trigger = %v, want the agent's MaxRuntime %v", got, wantSoft) + } +} + +// TestCriticOwnsDeadline_NilHandleFallsBackToMaxRuntime: the agent enables the +// critic but the host Monitor returns NO handle (nil) — there is no deadline-watch, +// so the run is unsupervised. It must fall back to the nominal MaxRuntime hard cap +// (the slow 200ms tool outlasts the 20ms MaxRuntime → the run errors), NOT run free +// up to the generous CriticAbsoluteMax runaway ceiling. +func TestCriticOwnsDeadline_NilHandleFallsBackToMaxRuntime(t *testing.T) { + m := slowModel() + cc := &capturingCritic{} // h is the nil interface → Monitor returns a nil handle + ex := run.New(run.Config{ + Registry: tool.NewRegistry(), + Models: func(ctx context.Context, _ string) (context.Context, llm.Model, error) { return ctx, m, nil }, + Ports: run.Ports{Critic: cc}, + Defaults: run.Defaults{CriticAbsoluteMax: time.Hour}, // generous ceiling; must NOT be what bounds the run + }) + res := ex.Run(context.Background(), + run.RunnableAgent{Name: "x", ModelTier: "m", MaxIterations: 5, MaxRuntime: 20 * time.Millisecond, + Critic: run.CriticConfig{Enabled: true}}, + slowToolInvocation("r", 200*time.Millisecond), "go") + if res.Err == nil { + t.Fatalf("critic-enabled run with a nil Monitor handle must fall back to the MaxRuntime hard cap; got output=%q err=nil", res.Output) } } diff --git a/run/critic_test.go b/run/critic_test.go index e617568..8047dee 100644 --- a/run/critic_test.go +++ b/run/critic_test.go @@ -61,8 +61,8 @@ func TestCriticRaisesStepCeiling(t *testing.T) { Registry: tool.NewRegistry(), Models: func(ctx context.Context, _ string) (context.Context, llm.Model, error) { return ctx, m, nil }, Ports: run.Ports{Critic: &fakeCritic{h: h}}, - // large soft timeout so the deadline-watch never interferes in the test - Defaults: run.Defaults{CriticSoftTimeout: time.Hour}, + // The fake handle's Deadline() is zero (no hard deadline), so the + // deadline-watch never interferes regardless of the soft trigger. }) res := ex.Run(context.Background(), run.RunnableAgent{Name: "x", ModelTier: "m", MaxIterations: 1, Critic: run.CriticConfig{Enabled: true}}, diff --git a/run/executor.go b/run/executor.go index 0458798..4b75010 100644 --- a/run/executor.go +++ b/run/executor.go @@ -29,13 +29,17 @@ type Defaults struct { MaxConsecutiveToolErrors int // loop guard; default 3 MaxSameToolCallRepeats int // retry-storm guard; default 3 CompactionThresholdRatio float64 // fraction of model context to compact at; default 0.7 - CriticSoftTimeout time.Duration // idle window before the critic wakes; default 90s - // CriticAbsoluteMax is the failsafe wall-clock ceiling for a critic-OWNED run - // (Ports.Critic set AND the agent enables it). For such a run MaxRuntime is the - // SOFT trigger, not a hard cap, and the critic's extendable backstop is the - // normal deadline — so this ceiling only fires if the critic never acts (a - // broken/nil host handle). Default 6h; never shorter than the run's MaxRuntime. - // Non-critic runs ignore it (they keep the literal MaxRuntime kill). + // CriticAbsoluteMax is the RUNAWAY ceiling for a critic-OWNED run (Ports.Critic + // set AND the agent enables it). For such a run MaxRuntime is the SOFT trigger, + // not a hard cap, and the critic's own extendable backstop is the normal + // deadline. This ceiling exists ONLY to stop a critic that never advances its + // deadline (a broken host handle) from running forever, so it is deliberately + // set FAR beyond any realistic backstop (default 24h): the host clamps its own + // backstop to a much smaller absolute max (e.g. mort's agents.critic. + // absolute_max_seconds = 6h), so the ceiling never pre-empts a healthy + // supervised run. Keep it well above the host's absolute max. Never shorter than + // the run's MaxRuntime. Non-critic runs ignore it (they keep the literal + // MaxRuntime kill). CriticAbsoluteMax time.Duration } @@ -58,11 +62,8 @@ func (d Defaults) withFallbacks() Defaults { if d.CompactionThresholdRatio <= 0 { d.CompactionThresholdRatio = 0.7 } - if d.CriticSoftTimeout <= 0 { - d.CriticSoftTimeout = 90 * time.Second - } if d.CriticAbsoluteMax <= 0 { - d.CriticAbsoluteMax = 6 * time.Hour + d.CriticAbsoluteMax = 24 * time.Hour } return d } @@ -289,19 +290,26 @@ func (e *Executor) Run(ctx context.Context, ra RunnableAgent, inv tool.Invocatio // MaxRuntime becomes the SOFT trigger (passed to startCritic), and the // critic's extendable backstop — watched in startCritic, which cancels via // cancelCause — is the real deadline. A slow-but-progressing run is given - // room up to the backstop; only a stalled one is killed. We still wrap a - // GENEROUS WithTimeout at CriticAbsoluteMax so a broken/nil critic handle - // can't run unbounded; that ceiling never fires before the critic's backstop. + // room up to that backstop; only a stalled one is killed. The base context + // gets a WithTimeout at CriticAbsoluteMax (default 24h) purely as a RUNAWAY + // guard for a critic that never advances its deadline: it is set FAR beyond + // any realistic backstop (the host clamps its own backstop to a much smaller + // absolute max, e.g. mort's 6h convar), so it does NOT pre-empt a healthy + // supervised run. If the host critic fails to ARM (nil handle), the run is + // unsupervised and we tighten the cap back down to MaxRuntime below. // A NESTED cause-carrying layer (cancelCause) lets a critic kill surface as a // distinct "killed": only an ErrCriticKill cause is consulted in statusFor; a // generic run error, a backstop expiry, or a caller cancel is classified by the // run error itself. - criticOwnsDeadline := e.cfg.Ports.Critic != nil && ra.Critic.Enabled + criticOwns := e.criticOwnsDeadline(ra) hardCap := maxRuntime - if criticOwnsDeadline { + if criticOwns { + // Runaway guard only — the critic's own (extendable) deadline-watch is the + // normal cap. Never shorter than the nominal budget, in case an operator + // sets MaxRuntime above the runaway ceiling (a degenerate config). hardCap = e.cfg.Defaults.CriticAbsoluteMax if hardCap < maxRuntime { - hardCap = maxRuntime // the failsafe ceiling is never shorter than the nominal budget + hardCap = maxRuntime } } timeoutCtx, cancelTimeout := context.WithTimeout(context.WithoutCancel(ctx), hardCap) @@ -310,9 +318,6 @@ func (e *Executor) Run(ctx context.Context, ra RunnableAgent, inv tool.Invocatio defer cancelCause(nil) runCtx, mergeCancel := MergeCancellation(runCtx, ctx) defer mergeCancel() - // The finalize defer (top of Run) now has a run context to read the - // cancellation cause from (shutdown vs critic-kill vs deadline vs cancel). - checkpointCause = func() error { return context.Cause(runCtx) } // Critic (optional): monitors the run for a stall, can nudge/extend/kill via // its host Escalator. When it owns the deadline, MaxRuntime is its soft trigger @@ -322,6 +327,22 @@ func (e *Executor) Run(ctx context.Context, ra RunnableAgent, inv tool.Invocatio critic, stopCritic := e.startCritic(runCtx, cancelCause, ra, info, maxRuntime) defer stopCritic() + // Unsupervised-run failsafe: the agent enabled the critic (so the base context + // got the generous runaway ceiling instead of MaxRuntime), but the host Monitor + // returned no handle — there is no deadline-watch. Without this the run would be + // bounded only by the 24h ceiling. Tighten it back to the nominal MaxRuntime so + // an unsupervised run can't hold its slot far past budget. mort's adapter always + // arms when the flag is set, so this is pure defence in depth. + if criticOwns && critic == nil { + var cancelUnsupervised context.CancelFunc + runCtx, cancelUnsupervised = context.WithTimeout(runCtx, maxRuntime) + defer cancelUnsupervised() + } + // The finalize defer (top of Run) now has a run context to read the + // cancellation cause from (shutdown vs critic-kill vs deadline vs cancel). Set + // AFTER the unsupervised-failsafe re-wrap so it reads the context the loop runs on. + checkpointCause = func() error { return context.Cause(runCtx) } + // Step instrumentation: accumulate Result.Steps + fire inv.OnStep, feed the // audit recorder, and keep the live iteration counter fresh. majordomo's // step observer hands us each completed iteration; we zip the model's tool