// to trace.ResourceNone (the global scope).
type globalRangeGenerator struct {
	ranges   map[string]activeRange
	seenSync bool
}

// Sync notifies the generator of an EventSync event.
func (g *globalRangeGenerator) Sync() {
	g.seenSync = true
}

// GlobalRange implements a handler for EventRange* events whose Scope.Kind is ResourceNone.
// It expects ev to be one such event.

	lastTs   trace.Time
	gs       map[trace.GoID]*goState
	ps       map[trace.ProcID]*procState
	ms       map[trace.ThreadID]*schedContext
	ranges   map[trace.ResourceID][]string
	tasks    map[trace.TaskID]string
	seenSync bool
	Go121    bool
}

type schedContext struct {
	M trace.ThreadID
	P trace.ProcID
	G trace.GoID
}

type goState struct {
	state   trace.GoState
	binding *schedContext
}

		t.Fatalf("could not start subprocess: %v", err)
	}
	r, err := traceparse.NewReader(stdOut)
	if err != nil {
		t.Fatalf("could not create trace.NewReader: %v", err)
	}
	var seen, seenSync bool
	i := 1
loop:
	for ; ; i++ {
		ev, err := r.ReadEvent()
		if err != nil {
			// We may have a broken tail to the trace -- that's OK.
			// We'll make sure we saw at least one complete generation.

		n int
	}
	out := [][]MutatorUtil{}
	stw := 0
	ps := []perP{}
	inGC := make(map[GoID]bool)
	states := make(map[GoID]GoState)
	bgMark := make(map[GoID]bool)
	procs := []procsCount{}
	seenSync := false

	// Helpers.
	handleSTW := func(r Range) bool {
		return flags&UtilSTW != 0 && isGCSTW(r)
	}
	handleMarkAssist := func(r Range) bool {
		return flags&UtilAssist != 0 && isGCMarkAssist(r)
	}