fix: timer usage across codebase (#14935)

it seems in some places we have been wrongly using the
timer.Reset() function, nicely exposed by an example
shared by @donatello https://go.dev/play/p/qoF71_D1oXD

this PR fixes all the usage comprehensively

cmd/admin-handlers.go

@@ -654,12 +654,10 @@ func (a adminAPIHandlers) ProfileHandler(w http.ResponseWriter, r *http.Request)
 	globalProfilerMu.Unlock()
 
 	timer := time.NewTimer(duration)
+	defer timer.Stop()
 	for {
 		select {
 		case <-ctx.Done():
-			if !timer.Stop() {
-				<-timer.C
-			}
 			for k, v := range globalProfiler {
 				v.Stop()
 				delete(globalProfiler, k)

cmd/admin-heal-ops.go

@@ -194,7 +194,6 @@ func (ahs *allHealState) periodicHealSeqsClean(ctx context.Context) {
 	for {
 		select {
 		case <-periodicTimer.C:
-			periodicTimer.Reset(time.Minute * 5)
 			now := UTCNow()
 			ahs.Lock()
 			for path, h := range ahs.healSeqMap {
@@ -203,6 +202,8 @@ func (ahs *allHealState) periodicHealSeqsClean(ctx context.Context) {
 				}
 			}
 			ahs.Unlock()
+
+			periodicTimer.Reset(time.Minute * 5)
 		case <-ctx.Done():
 			// server could be restarting - need
 			// to exit immediately
@@ -581,12 +582,7 @@ func (h *healSequence) pushHealResultItem(r madmin.HealResultItem) error {
 	// heal-results in memory and the client has not consumed it
 	// for too long.
 	unconsumedTimer := time.NewTimer(healUnconsumedTimeout)
-	defer func() {
+	defer unconsumedTimer.Stop()
-		// stop the timeout timer so it is garbage collected.
-		if !unconsumedTimer.Stop() {
-			<-unconsumedTimer.C
-		}
-	}()
 
 	var itemsLen int
 	for {

cmd/background-newdisks-heal-ops.go

@@ -312,9 +312,6 @@ func monitorLocalDisksAndHeal(ctx context.Context, z *erasureServerPools, bgSeq
 		case <-ctx.Done():
 			return
 		case <-diskCheckTimer.C:
-			// Reset to next interval.
-			diskCheckTimer.Reset(defaultMonitorNewDiskInterval)
-
 			var erasureSetInPoolDisksToHeal []map[int][]StorageAPI
 
 			healDisks := globalBackgroundHealState.getHealLocalDiskEndpoints()
@@ -448,6 +445,9 @@ func monitorLocalDisksAndHeal(ctx context.Context, z *erasureServerPools, bgSeq
 				}
 			}
 			wg.Wait()
+
+			// Reset for next interval.
+			diskCheckTimer.Reset(defaultMonitorNewDiskInterval)
 		}
 	}
 }

cmd/bucket-replication-stats.go

@@ -161,7 +161,7 @@ func NewReplicationStats(ctx context.Context, objectAPI ObjectLayer) *Replicatio
 
 // load replication metrics at cluster start from initial data usage
 func (r *ReplicationStats) loadInitialReplicationMetrics(ctx context.Context) {
-	rTimer := time.NewTimer(time.Minute * 1)
+	rTimer := time.NewTimer(time.Minute)
 	defer rTimer.Stop()
 	var (
 		dui DataUsageInfo
@@ -169,6 +169,7 @@ func (r *ReplicationStats) loadInitialReplicationMetrics(ctx context.Context) {
 	)
 outer:
 	for {
+		rTimer.Reset(time.Minute)
 		select {
 		case <-ctx.Done():
 			return

cmd/bucket-replication.go

@@ -1926,7 +1926,6 @@ func (p *ReplicationPool) periodicResyncMetaSave(ctx context.Context, objectAPI
 	for {
 		select {
 		case <-resyncTimer.C:
-			resyncTimer.Reset(resyncTimeInterval)
 			now := UTCNow()
 			p.resyncState.RLock()
 			for bucket, brs := range p.resyncState.statusMap {
@@ -1947,6 +1946,8 @@ func (p *ReplicationPool) periodicResyncMetaSave(ctx context.Context, objectAPI
 				}
 			}
 			p.resyncState.RUnlock()
+
+			resyncTimer.Reset(resyncTimeInterval)
 		case <-ctx.Done():
 			// server could be restarting - need
 			// to exit immediately

cmd/data-scanner.go

@@ -197,9 +197,6 @@ func runDataScanner(pctx context.Context, objAPI ObjectLayer) {
 		case <-ctx.Done():
 			return
 		case <-scannerTimer.C:
-			// Reset the timer for next cycle.
-			scannerTimer.Reset(scannerCycle.Get())
-
 			if intDataUpdateTracker.debug {
 				console.Debugln("starting scanner cycle")
 			}
@@ -232,6 +229,9 @@ func runDataScanner(pctx context.Context, objAPI ObjectLayer) {
 					logger.LogIf(ctx, err)
 				}
 			}
+
+			// Reset the timer for next cycle.
+			scannerTimer.Reset(scannerCycle.Get())
 		}
 	}
 }

cmd/disk-cache-backend.go

@@ -1630,8 +1630,6 @@ func (c *diskCache) cleanupStaleUploads(ctx context.Context) {
 		case <-ctx.Done():
 			return
 		case <-timer.C:
-			// Reset for the next interval
-			timer.Reset(cacheStaleUploadCleanupInterval)
 			now := time.Now()
 			readDirFn(pathJoin(c.dir, minioMetaBucket, cacheMultipartDir), func(shaDir string, typ os.FileMode) error {
 				return readDirFn(pathJoin(c.dir, minioMetaBucket, cacheMultipartDir, shaDir), func(uploadIDDir string, typ os.FileMode) error {
@@ -1662,6 +1660,9 @@ func (c *diskCache) cleanupStaleUploads(ctx context.Context) {
 				}
 				return nil
 			})
+
+			// Reset for the next interval
+			timer.Reset(cacheStaleUploadCleanupInterval)
 		}
 	}
 }

cmd/erasure-sets.go

@@ -301,14 +301,14 @@ func (s *erasureSets) monitorAndConnectEndpoints(ctx context.Context, monitorInt
 		case <-ctx.Done():
 			return
 		case <-monitor.C:
-			// Reset the timer once fired for required interval.
-			monitor.Reset(monitorInterval)
-
 			if serverDebugLog {
 				console.Debugln("running disk monitoring")
 			}
 
 			s.connectDisks()
+
+			// Reset the timer for next interval
+			monitor.Reset(monitorInterval)
 		}
 	}
 }
@@ -504,9 +504,6 @@ func (s *erasureSets) cleanupDeletedObjects(ctx context.Context) {
 		case <-ctx.Done():
 			return
 		case <-timer.C:
-			// Reset for the next interval
-			timer.Reset(globalAPIConfig.getDeleteCleanupInterval())
-
 			var wg sync.WaitGroup
 			for _, set := range s.sets {
 				wg.Add(1)
@@ -519,6 +516,9 @@ func (s *erasureSets) cleanupDeletedObjects(ctx context.Context) {
 				}(set)
 			}
 			wg.Wait()
+
+			// Reset for the next interval
+			timer.Reset(globalAPIConfig.getDeleteCleanupInterval())
 		}
 	}
 }
@@ -532,9 +532,6 @@ func (s *erasureSets) cleanupStaleUploads(ctx context.Context) {
 		case <-ctx.Done():
 			return
 		case <-timer.C:
-			// Reset for the next interval
-			timer.Reset(globalAPIConfig.getStaleUploadsCleanupInterval())
-
 			var wg sync.WaitGroup
 			for _, set := range s.sets {
 				wg.Add(1)
@@ -547,6 +544,9 @@ func (s *erasureSets) cleanupStaleUploads(ctx context.Context) {
 				}(set)
 			}
 			wg.Wait()
+
+			// Reset for the next interval
+			timer.Reset(globalAPIConfig.getStaleUploadsCleanupInterval())
 		}
 	}
 }

cmd/fs-v1-multipart.go

@@ -887,8 +887,6 @@ func (fs *FSObjects) cleanupStaleUploads(ctx context.Context) {
 		case <-ctx.Done():
 			return
 		case <-bgAppendTmpCleaner.C:
-			bgAppendTmpCleaner.Reset(bgAppendsCleanupInterval)
-
 			foundUploadIDs := fs.getAllUploadIDs(ctx)
 
 			// Remove background append map from the memory
@@ -915,10 +913,8 @@ func (fs *FSObjects) cleanupStaleUploads(ctx context.Context) {
 				}
 			}
 
+			bgAppendTmpCleaner.Reset(bgAppendsCleanupInterval)
 		case <-expiryUploadsTimer.C:
-			// Reset for the next interval
-			expiryUploadsTimer.Reset(globalAPIConfig.getStaleUploadsCleanupInterval())
-
 			expiry := globalAPIConfig.getStaleUploadsExpiry()
 			now := time.Now()
 
@@ -944,6 +940,9 @@ func (fs *FSObjects) cleanupStaleUploads(ctx context.Context) {
 					fs.appendFileMapMu.Unlock()
 				}
 			}
+
+			// Reset for the next interval
+			expiryUploadsTimer.Reset(globalAPIConfig.getStaleUploadsCleanupInterval())
 		}
 	}
 }

cmd/lock-rest-server.go

@@ -239,10 +239,10 @@ func lockMaintenance(ctx context.Context) {
 		case <-ctx.Done():
 			return
 		case <-lkTimer.C:
+			globalLockServer.expireOldLocks(lockValidityDuration)
+
 			// Reset the timer for next cycle.
 			lkTimer.Reset(lockMaintenanceInterval)
-
-			globalLockServer.expireOldLocks(lockValidityDuration)
 		}
 	}
 }

cmd/site-replication.go

@@ -3330,10 +3330,10 @@ func (c *SiteReplicationSys) startHealRoutine(ctx context.Context, objAPI Object
 	defer healTimer.Stop()
 
 	for {
+		healTimer.Reset(siteHealTimeInterval)
+
 		select {
 		case <-healTimer.C:
-			healTimer.Reset(siteHealTimeInterval)
-
 			c.RLock()
 			enabled := c.enabled
 			c.RUnlock()

internal/dsync/drwmutex.go

@@ -255,12 +255,12 @@ func (dm *DRWMutex) startContinousLockRefresh(lockLossCallback func(), id, sourc
 		defer refreshTimer.Stop()
 
 		for {
+			refreshTimer.Reset(dm.refreshInterval)
+
 			select {
 			case <-ctx.Done():
 				return
 			case <-refreshTimer.C:
-				refreshTimer.Reset(dm.refreshInterval)
-
 				noQuorum, err := refreshLock(ctx, dm.clnt, id, source, quorum)
 				if err == nil && noQuorum {
 					// Clean the lock locally and in remote nodes