Merge pull request #82 from rauls5382/mutex

Add support for golang legacy mutex profiles

profile/legacy_profile.go

 	return int64(float64(count) * scale), int64(float64(size) * scale)
 }
 
-// parseContention parses a contentionz profile and returns a newly
-// populated Profile.
-func parseContention(b []byte) (p *Profile, err error) {
+// parseContention parses a mutex or contention profile. There are 2 cases:
+// "--- contentionz " for legacy C++ profiles (and backwards compatibility)
+// "--- mutex:" or "--- contention:" for profiles generated by the Go runtime.
+func parseContention(b []byte) (*Profile, error) {
 	s := bufio.NewScanner(bytes.NewBuffer(b))
 	if !s.Scan() {
 		if err := s.Err(); err != nil {
 		}
 		return nil, errUnrecognized
 	}
-	line := s.Text()
 
-	if !strings.HasPrefix(line, "--- contention") {
+	switch l := s.Text(); {
+	case strings.HasPrefix(l, "--- contentionz "):
+	case strings.HasPrefix(l, "--- mutex:"):
+	case strings.HasPrefix(l, "--- contention:"):
+	default:
 		return nil, errUnrecognized
 	}
 
-	p = &Profile{
+	p := &Profile{
 		PeriodType: &ValueType{Type: "contentions", Unit: "count"},
 		Period:     1,
 		SampleType: []*ValueType{
 		return nil, err
 	}
 
-	if err = parseAdditionalSections(s, p); err != nil {
+	if err := parseAdditionalSections(s, p); err != nil {
 		return nil, err
 	}