if err != nil {
				return
			}
			if len(mergeCh) == 0 {
				// Flush if nothing is queued
				w.(http.Flusher).Flush()
			}
			grid.PutByteBuffer(ev)
		case <-emptyEventTicker:
			if err := enc.Encode(struct{ Records []event.Event }{}); err != nil {
				return
			}
			w.(http.Flusher).Flush()
		case <-keepAliveTicker:
			if _, err := w.Write([]byte(" ")); err != nil {
				return
			}

	// bound is pretty loose, but avoids counting
	// lots of varint sizes.
	//
	// Add 1 because we might also write a traceAllocFreeTypesBatch byte.
	var flushed bool
	w, flushed = w.ensure(1 + maxBytes)
	if flushed {
		// Annotate the batch as containing types.
		w.byte(byte(traceAllocFreeTypesBatch))
	}

	// Emit type.
	w.varint(uint64(node.id))
	w.varint(uint64(uintptr(unsafe.Pointer(typ))))

}

func testTrailersServerToClient(t *testing.T, mode testMode, flush bool) {
	const body = "Some body"
	cst := newClientServerTest(t, mode, HandlerFunc(func(w ResponseWriter, r *Request) {
		w.Header().Set("Trailer", "Server-Trailer-A, Server-Trailer-B")
		w.Header().Add("Trailer", "Server-Trailer-C")

		io.WriteString(w, body)
		if flush {
			w.(Flusher).Flush()
		}

		// How handlers set Trailers: declare it ahead of time

	// flush their own buffers in traceThreadDestroy.
	//
	// Snapshotting freem is necessary because Ms can continue to emit events
	// while they're still on that list. Removal from sched.freem is serialized with
	// this snapshot, so either we'll capture an m on sched.freem and race with
	// the removal to flush its buffers (resolved by traceThreadDestroy acquiring

				return
			}
			grid.PutByteBuffer(entry)
			if len(traceCh) == 0 {
				// Flush if nothing is queued
				w.(http.Flusher).Flush()
			}
		case <-keepAliveTicker.C:
			if len(traceCh) > 0 {
				continue
			}
			if _, err := w.Write([]byte(" ")); err != nil {
				return
			}
			w.(http.Flusher).Flush()
		case <-ctx.Done():
			return
		}
	}
}

	systemstack(freeStackSpans)

	// Ensure all mcaches are flushed. Each P will flush its own
	// mcache before allocating, but idle Ps may not. Since this
	// is necessary to sweep all spans, we need to ensure all
	// mcaches are flushed before we start the next GC cycle.
	//
	// While we're here, flush the page cache for idle Ps to avoid
	// having pages get stuck on them. These pages are hidden from

func traceSnapshotMemory(gen uintptr) {
	assertWorldStopped()

	// Write a batch containing information that'll be necessary to
	// interpret the events.
	var flushed bool
	w := unsafeTraceExpWriter(gen, nil, traceExperimentAllocFree)
	w, flushed = w.ensure(1 + 4*traceBytesPerNumber)
	if flushed {
		// Annotate the batch as containing additional info.
		w.byte(byte(traceAllocFreeInfoBatch))
	}

	// Emit info.

	tx.Flush(&knftables.Set{
		Name: clusterIPsSet,
	})
	tx.Flush(&knftables.Map{
		Name: firewallIPsMap,
	})
	tx.Flush(&knftables.Map{
		Name: noEndpointServicesMap,
	})
	tx.Flush(&knftables.Map{
		Name: noEndpointNodePortsMap,
	})
	tx.Flush(&knftables.Map{
		Name: serviceIPsMap,
	})
	tx.Flush(&knftables.Map{
		Name: serviceNodePortsMap,

				return
			}
			if len(diffCh) == 0 {
				// Flush if nothing is queued
				w.(http.Flusher).Flush()
			}
		case <-keepAliveTicker.C:
			if len(diffCh) > 0 {
				continue
			}
			if _, err := w.Write([]byte(" ")); err != nil {
				return
			}
			w.(http.Flusher).Flush()
		case <-ctx.Done():
			return
		}
	}
}

		n += n0
		if err != nil || n0 < sniffLen {
			return n, err
		}
	}

	w.w.Flush()  // get rid of any previous writes
	w.cw.flush() // make sure Header is written; flush data to rwc

	// Now that cw has been flushed, its chunking field is guaranteed initialized.
	if !w.cw.chunking && w.bodyAllowed() {
		n0, err := rf.ReadFrom(src)
		n += n0
		w.written += n0