native histogram: Fix race between Write and addExemplar

Follow-up to 1608

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
This commit is contained in:
György Krajcsovits 2024-09-06 11:01:04 +02:00
parent ef2f87ea98
commit 1e398ccb12
1 changed files with 6 additions and 4 deletions

View File

@ -844,9 +844,7 @@ func (h *histogram) Write(out *dto.Metric) error {
}}
}
// If exemplars are not configured, the cap will be 0.
// So append is not needed in this case.
if cap(h.nativeExemplars.exemplars) > 0 {
if h.nativeExemplars.isEnabled() {
h.nativeExemplars.Lock()
his.Exemplars = append(his.Exemplars, h.nativeExemplars.exemplars...)
h.nativeExemplars.Unlock()
@ -1665,6 +1663,10 @@ type nativeExemplars struct {
exemplars []*dto.Exemplar
}
func (n *nativeExemplars) isEnabled() bool {
return n.ttl != -1
}
func makeNativeExemplars(ttl time.Duration, maxCount int) nativeExemplars {
if ttl == 0 {
ttl = 5 * time.Minute
@ -1686,7 +1688,7 @@ func makeNativeExemplars(ttl time.Duration, maxCount int) nativeExemplars {
}
func (n *nativeExemplars) addExemplar(e *dto.Exemplar) {
if n.ttl == -1 {
if !n.isEnabled() {
return
}