Make metrics.Registry.Deregister thread safe

Author: algorandskiy

ledger/metrics_test.go

@@ -27,10 +27,13 @@ import (
 	"github.com/algorand/go-algorand/ledger/ledgercore"
 	ledgertesting "github.com/algorand/go-algorand/ledger/testing"
 	"github.com/algorand/go-algorand/protocol"
+	"github.com/algorand/go-algorand/test/partitiontest"
 	"github.com/algorand/go-algorand/util/metrics"
 )
 
 func TestMetricsReload(t *testing.T) {
+	partitiontest.PartitionTest(t)
+
 	mt := metricsTracker{}
 	accts := ledgertesting.RandomAccounts(1, true)
 	ml := makeMockLedgerForTracker(t, true, 1, protocol.ConsensusCurrentVersion, []map[basics.Address]basics.AccountData{accts})

util/metrics/counter.go

@@ -63,7 +63,7 @@ func (counter *Counter) Deregister(reg *Registry) {
 // Inc increases counter by 1
 // Much faster if labels is nil or empty.
 func (counter *Counter) Inc(labels map[string]string) {
-	if labels == nil || len(labels) == 0 {
+	if len(labels) == 0 {
 		counter.fastAddUint64(1)
 	} else {
 		counter.Add(1.0, labels)
@@ -98,7 +98,7 @@ func (counter *Counter) Add(x float64, labels map[string]string) {
 // If labels is nil this is much faster than Add()
 // Calls through to Add() if labels is not nil.
 func (counter *Counter) AddUint64(x uint64, labels map[string]string) {
-	if labels == nil || len(labels) == 0 {
+	if len(labels) == 0 {
 		counter.fastAddUint64(x)
 	} else {
 		counter.Add(float64(x), labels)
@@ -108,7 +108,7 @@ func (counter *Counter) AddUint64(x uint64, labels map[string]string) {
 // AddMicrosecondsSince increases counter by microseconds between Time t and now.
 // Fastest if labels is nil
 func (counter *Counter) AddMicrosecondsSince(t time.Time, labels map[string]string) {
-	counter.AddUint64(uint64(time.Now().Sub(t).Microseconds()), labels)
+	counter.AddUint64(uint64(time.Since(t).Microseconds()), labels)
 }
 
 func (counter *Counter) fastAddUint64(x uint64) {

util/metrics/registry.go

@@ -50,6 +50,8 @@ func (r *Registry) Register(metric Metric) {
 
 // Deregister removes the given metric to the registry
 func (r *Registry) Deregister(metric Metric) {
+	r.metricsMu.Lock()
+	defer r.metricsMu.Unlock()
 	for i, m := range r.metrics {
 		if m == metric {
 			r.metrics = append(r.metrics[:i], r.metrics[i+1:]...)

util/metrics/service.go

@@ -37,6 +37,7 @@ var (
 var (
 	// the duration of which we'll keep a metric in-memory and keep reporting it.
 	// when a metric time expires, it would get removed.
+	// TODO: implement or remove
 	maxMetricRetensionDuration = time.Duration(5) * time.Minute
 )