Method sendToOutChan

pkg/agent/proxy/syncMock/syncMock.go:328–367

sendToOutChan is the single send path to outChan. Holds outChanMu read-lock across the whole observation + send so CloseOutChan (the writer-lock holder) cannot interleave a close between our not-closed check and the chansend. Tries a non-blocking send first (the fast, jitter-free common case where

(mock *models.Mock)

// customer-facing recording-loss flake and is strictly worse than a
// 200 ms worst-case shutdown delay.
func (m *SyncMockManager) sendToOutChan(mock *models.Mock) {
	m.outChanMu.RLock()
	defer m.outChanMu.RUnlock()
	if m.outChanClosed || m.outChan == nil {
		return
	}
	select {
	case m.outChan <- mock:
		return
	default:
	}
	// Fast path full. Bounded block so normal scheduling jitter
	// doesn't cost us a mock.
	timer := time.NewTimer(sendBudget)
	select {
	case m.outChan <- mock:
		timer.Stop()
	case <-timer.C:
		n := m.dropCount.Add(1)
		// The existing per-1024 sampled Error fires at n==1 AND every
		// subsequent 1024th drop. Per-Copilot review on #4176, the
		// "your recording is now lossy" wording lives on the same n==1
		// branch rather than as a separate Warn so operators see one
		// clear signal at the moment capture goes lossy, instead of
		// two separate lines that may interleave with other logs.
		// Subsequent sampled emissions stay terse to avoid drowning a
		// stuck consumer's goroutine in its own logging.
		if n == 1 || n%sendDropSampleRate == 0 {
			msg := "syncMock outChan overflow; mock dropped — consumer can't keep up with mock production"
			if n == 1 {
				msg = "syncMock outChan overflow on FIRST drop — mock recording is now LOSSY for this session; subsequent overflow drops are silent except for the per-1024 sampled line. Reduce concurrent test load, upgrade to a release with a larger outChan capacity, or investigate consumer-side stalls (slow disk / network to k8s-proxy) before re-running for a clean recording."
			}
			m.dropLogger().Error(msg,
				zap.Uint64("dropsSoFar", n),
				zap.Int("outChanCap", cap(m.outChan)),
				zap.Duration("budget", sendBudget),
			)
		}
	}
}

// DropCount exposes the cumulative drop counter for tests and
// external observability. The value is monotonically increasing;