| 1 | package control |
| 2 | |
| 3 | import ( |
| 4 | "errors" |
| 5 | "log/slog" |
| 6 | "time" |
| 7 | |
| 8 | "reasonix/internal/sessioninbox" |
| 9 | ) |
| 10 | |
| 11 | const maxInboxDispatchRetryAttempts = 3 |
| 12 | |
| 13 | // ErrInboxRuntimeUnpublished means the host owns the next dispatch kick: |
| 14 | // either this runtime is a candidate or it was replaced before admission. |
| 15 | var ErrInboxRuntimeUnpublished = errors.New("inbox runtime is not published") |
| 16 | |
| 17 | // NotifyInboxRuntimeReady is called after a host publishes a complete runtime. |
| 18 | func (c *Controller) NotifyInboxRuntimeReady() { c.maybeDispatchInbox() } |
| 19 | |
| 20 | func (c *Controller) SetBeforeInboxDispatch(before func(*Controller) (func(), error)) { |
| 21 | c.mu.Lock() |
| 22 | c.modelSettings.beforeInboxDispatch = before |
| 23 | c.mu.Unlock() |
| 24 | } |
| 25 | |
| 26 | type inboxDispatchResult int |
| 27 | |
| 28 | const ( |
| 29 | inboxDispatchIdle inboxDispatchResult = iota |
| 30 | inboxDispatchStarted |
| 31 | inboxDispatchRetry |
| 32 | ) |
| 33 | |
| 34 | // endRotation releases the admission gate and republishes durable queue work. |
| 35 | func (c *Controller) endRotation() { |
| 36 | c.mu.Lock() |
| 37 | c.rotating = false |
| 38 | c.mu.Unlock() |
| 39 | c.maybeDispatchInbox() |
| 40 | } |
| 41 | |
| 42 | // maybeDispatchInbox is a level-triggered kick, not a one-shot edge. Every |
| 43 | // caller publishes pending work before checking whether a dispatcher is live. |
| 44 | // The active dispatcher clears dispatching only while holding the same lock |
| 45 | // after observing no pending kick, so a completion, rotation release, or steer |
| 46 | // rejection can never disappear in the handoff window. |
| 47 | func (c *Controller) maybeDispatchInbox() { |
| 48 | c.inbox.mu.Lock() |
| 49 | if c.inbox.closed { |
| 50 | c.inbox.mu.Unlock() |
| 51 | return |
| 52 | } |
| 53 | c.inbox.dispatchPending = true |
| 54 | if c.inbox.dispatching { |
| 55 | c.inbox.mu.Unlock() |
| 56 | return |
| 57 | } |
| 58 | c.inbox.dispatching = true |
| 59 | c.inbox.mu.Unlock() |
| 60 | c.mu.Lock() |
| 61 | hostAdmission := c.modelSettings.beforeInboxDispatch != nil |
| 62 | c.mu.Unlock() |
| 63 | if hostAdmission { |
| 64 | // Enqueue/resume can be called with the host's publication lock held. |
| 65 | // Never synchronously reenter that lock through its admission callback. |
| 66 | c.autosaveWG.Go(c.drainInboxDispatch) |
| 67 | return |
| 68 | } |
| 69 | c.drainInboxDispatch() |
| 70 | } |
| 71 | |
| 72 | func (c *Controller) drainInboxDispatch() { |
| 73 | for { |
| 74 | c.inbox.mu.Lock() |
| 75 | if !c.inbox.dispatchPending { |
| 76 | c.inbox.dispatching = false |
| 77 | c.inbox.mu.Unlock() |
| 78 | return |
| 79 | } |
| 80 | c.inbox.dispatchPending = false |
| 81 | c.inbox.mu.Unlock() |
| 82 | |
| 83 | switch c.dispatchInboxOnce() { |
| 84 | case inboxDispatchRetry: |
| 85 | c.scheduleInboxDispatchRetry() |
| 86 | case inboxDispatchStarted, inboxDispatchIdle: |
| 87 | c.resetInboxDispatchRetries() |
| 88 | } |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | // dispatchInboxOnce admits one FIFO item when every runtime gate is open. A |
| 93 | // started turn owns the next kick through finishGuardedTurn; this method never |
| 94 | // loops over multiple items while that turn is active. |
| 95 | func (c *Controller) dispatchInboxOnce() inboxDispatchResult { |
| 96 | if c.PendingPrompt() { |
| 97 | return inboxDispatchIdle |
| 98 | } |
| 99 | c.mu.Lock() |
| 100 | busy := c.bodyActiveLocked() || c.finalizingLocked() || c.maintenance != nil || c.rotating || c.closed |
| 101 | c.mu.Unlock() |
| 102 | if busy { |
| 103 | return inboxDispatchIdle |
| 104 | } |
| 105 | // Controllers without persistence cannot own a durable inbox. Rotation and |
| 106 | // turn-completion hooks are shared with those controllers, so treat the |
| 107 | // missing path as an empty queue instead of retrying a permanent condition. |
| 108 | if c.SessionPath() == "" && !c.sessionEngineEnabled() { |
| 109 | return inboxDispatchIdle |
| 110 | } |
| 111 | meta, ok, err := c.nextInboxDispatchItem() |
| 112 | if err != nil { |
| 113 | slog.Warn("controller: open inbox for dispatch", "err", err) |
| 114 | return inboxDispatchRetry |
| 115 | } |
| 116 | c.inbox.mu.Lock() |
| 117 | beforeSubmit := c.inbox.beforeDispatchSubmit |
| 118 | c.inbox.mu.Unlock() |
| 119 | if !ok { |
| 120 | return inboxDispatchIdle |
| 121 | } |
| 122 | if beforeSubmit != nil { |
| 123 | if err := beforeSubmit(meta.ID); err != nil { |
| 124 | slog.Warn("controller: inbox dispatch hook", "err", err, "id", meta.ID) |
| 125 | return inboxDispatchRetry |
| 126 | } |
| 127 | } |
| 128 | receipt, err := c.TrySubmitInboxItem(meta.ID) |
| 129 | if err != nil { |
| 130 | if errors.Is(err, sessioninbox.ErrContentChanged) || errors.Is(err, sessioninbox.ErrOrderChanged) || errors.Is(err, sessioninbox.ErrNotFound) { |
| 131 | // A prepared candidate was invalidated. Reselect from the authoritative |
| 132 | // queue through the existing level-triggered loop, without a timer. |
| 133 | c.inbox.mu.Lock() |
| 134 | c.inbox.dispatchPending = true |
| 135 | c.inbox.mu.Unlock() |
| 136 | return inboxDispatchIdle |
| 137 | } |
| 138 | if errors.Is(err, ErrInboxRuntimeUnpublished) || errors.Is(err, ErrTurnRunning) { |
| 139 | return inboxDispatchIdle |
| 140 | } |
| 141 | slog.Warn("controller: dispatch inbox item", "err", err, "id", meta.ID) |
| 142 | return inboxDispatchRetry |
| 143 | } |
| 144 | if receipt.Disposition == sessioninbox.DispositionStarted { |
| 145 | return inboxDispatchStarted |
| 146 | } |
| 147 | // A competing turn or rotation owns the next kick when its gate releases. |
| 148 | return inboxDispatchIdle |
| 149 | } |
| 150 | |
| 151 | func (c *Controller) nextInboxDispatchItem() (sessioninbox.InboxItemMeta, bool, error) { |
| 152 | c.inbox.scanMu.Lock() |
| 153 | defer c.inbox.scanMu.Unlock() |
| 154 | c.inbox.mu.Lock() |
| 155 | closed := c.inbox.closed |
| 156 | afterScan := c.inbox.afterDispatchScan |
| 157 | c.inbox.mu.Unlock() |
| 158 | if closed { |
| 159 | return sessioninbox.InboxItemMeta{}, false, nil |
| 160 | } |
| 161 | st, err := c.ensureInbox() |
| 162 | if err != nil { |
| 163 | return sessioninbox.InboxItemMeta{}, false, err |
| 164 | } |
| 165 | // NextQueued refreshes disk state and may create its transaction-lock |
| 166 | // directory. Keep that access inside the same shutdown boundary as Open. |
| 167 | meta, ok := st.NextQueued() |
| 168 | if afterScan != nil { |
| 169 | afterScan(ok) |
| 170 | } |
| 171 | return meta, ok, nil |
| 172 | } |
| 173 | |
| 174 | func (c *Controller) scheduleInboxDispatchRetry() { |
| 175 | c.inbox.mu.Lock() |
| 176 | if c.inbox.dispatchRetryScheduled || c.inbox.dispatchRetryAttempts >= maxInboxDispatchRetryAttempts { |
| 177 | c.inbox.mu.Unlock() |
| 178 | return |
| 179 | } |
| 180 | attempt := c.inbox.dispatchRetryAttempts |
| 181 | c.inbox.dispatchRetryAttempts++ |
| 182 | c.inbox.dispatchRetryScheduled = true |
| 183 | schedule := c.inbox.scheduleDispatchRetry |
| 184 | c.inbox.mu.Unlock() |
| 185 | |
| 186 | delay := [...]time.Duration{50 * time.Millisecond, 200 * time.Millisecond, 500 * time.Millisecond}[attempt] |
| 187 | retry := func() { |
| 188 | c.inbox.mu.Lock() |
| 189 | c.inbox.dispatchRetryScheduled = false |
| 190 | c.inbox.mu.Unlock() |
| 191 | c.maybeDispatchInbox() |
| 192 | } |
| 193 | if schedule != nil { |
| 194 | schedule(delay, retry) |
| 195 | return |
| 196 | } |
| 197 | time.AfterFunc(delay, retry) |
| 198 | } |
| 199 | |
| 200 | func (c *Controller) resetInboxDispatchRetries() { |
| 201 | c.inbox.mu.Lock() |
| 202 | c.inbox.dispatchRetryAttempts = 0 |
| 203 | c.inbox.mu.Unlock() |
| 204 | } |
| 205 |