Function nameArguments

stack/stack.go:804–860

Private stuff. nameArguments is a post-processing step where Args are 'named' with numbers.

(goroutines []*Goroutine)

// nameArguments is a post-processing step where Args are 'named' with numbers.
func nameArguments(goroutines []*Goroutine) {
	// Set a name for any pointer occurring more than once.
	type object struct {
		args      []*Arg
		inPrimary bool
	}
	objects := map[uint64]object{}
	// Enumerate all the arguments.
	primary := true
	visit := func(arg *Arg) {
		if arg.IsPtr {
			objects[arg.Value] = object{
				args:      append(objects[arg.Value].args, arg),
				inPrimary: objects[arg.Value].inPrimary || primary,
			}
		}
	}
	for i, g := range goroutines {
		primary = i == 0
		for _, c := range g.Stack.Calls {
			c.Args.walk(visit)
		}
		// CreatedBy.Args is never set.
	}
	order := make(uint64Slice, 0, len(objects)/2)
	for k, obj := range objects {
		if len(obj.args) > 1 && obj.inPrimary {
			order = append(order, k)
		}
	}
	sort.Sort(order)
	nextID := 1
	for _, k := range order {
		for _, arg := range objects[k].args {
			arg.Name = fmt.Sprintf("#%d", nextID)
		}
		nextID++
	}

	// Now do the rest. This is done so the output is deterministic.
	order = make(uint64Slice, 0, len(objects))
	for k := range objects {
		order = append(order, k)
	}
	sort.Sort(order)
	for _, k := range order {
		// Process the remaining pointers, they were not referenced by primary
		// thread so will have higher IDs.
		if objects[k].inPrimary {
			continue
		}
		for _, arg := range objects[k].args {
			arg.Name = fmt.Sprintf("#%d", nextID)
		}
		nextID++
	}
}