addBuiltin(sSTWGOMAXPROCS, "GOMAXPROCS")
	addBuiltin(sSTWStartTrace, "start trace")
	addBuiltin(sSTWStopTrace, "stop trace")
	addBuiltin(sSTWCountPagesInUse, "CountPagesInUse (test)")
	addBuiltin(sSTWReadMetricsSlow, "ReadMetricsSlow (test)")
	addBuiltin(sSTWReadMemStatsSlow, "ReadMemStatsSlow (test)")
	addBuiltin(sSTWPageCachePagesLeaked, "PageCachePagesLeaked (test)")
	addBuiltin(sSTWResetDebugLog, "ResetDebugLog (test)")

	if addErr != nil {

	// Tests whether readMetrics produces values aligning
	// with ReadMemStats while the world is stopped.
	var mstats runtime.MemStats
	_, samples := prepareAllMetricsSamples()
	runtime.ReadMetricsSlow(&mstats, unsafe.Pointer(&samples[0]), len(samples), cap(samples))

	checkUint64 := func(t *testing.T, m string, got, want uint64) {
		t.Helper()
		if got != want {
			t.Errorf("metric %q: got %d, want %d", m, got, want)

	return (*profBuf)(p).read(mode)
}

func (p *ProfBuf) Close() {
	(*profBuf)(p).close()
}

type CPUStats = cpuStats

func ReadCPUStats() CPUStats {
	return work.cpuStats
}

func ReadMetricsSlow(memStats *MemStats, samplesp unsafe.Pointer, len, cap int) {
	stw := stopTheWorld(stwForTestReadMetricsSlow)

	// Initialize the metrics beforehand because this could
	// allocate and skew the stats.
	metricsLock()

	stwStopTrace                                    // "stop trace"
	stwForTestCountPagesInUse                       // "CountPagesInUse (test)"
	stwForTestReadMetricsSlow                       // "ReadMetricsSlow (test)"
	stwForTestReadMemStatsSlow                      // "ReadMemStatsSlow (test)"
	stwForTestPageCachePagesLeaked                  // "PageCachePagesLeaked (test)"