util: fix panic cause by concurrent map iteration and write in memory usage alarm

planner/core/common_plans.go

@@ -869,8 +869,8 @@ func getRuntimeInfo(ctx sessionctx.Context, p Plan, runtimeStatsColl *execdetail
 	if runtimeStatsColl != nil && runtimeStatsColl.ExistsCopStats(explainID) {
 		copStats = runtimeStatsColl.GetCopStats(explainID)
 	}
-	memTracker = ctx.GetSessionVars().StmtCtx.MemTracker.SearchTrackerWithoutLock(p.ID())
-	diskTracker = ctx.GetSessionVars().StmtCtx.DiskTracker.SearchTrackerWithoutLock(p.ID())
+	memTracker = ctx.GetSessionVars().StmtCtx.MemTracker.SearchTrackerWithLock(p.ID())
+	diskTracker = ctx.GetSessionVars().StmtCtx.DiskTracker.SearchTrackerWithLock(p.ID())
 	return
 }
 

util/execdetails/execdetails.go

@@ -32,17 +32,17 @@ import (
 
 // ExecDetails contains execution detail information.
 type ExecDetails struct {
-	CalleeAddress    string
-	CopTime          time.Duration
-	BackoffTime      time.Duration
-	LockKeysDuration time.Duration
-	BackoffSleep     map[string]time.Duration
-	BackoffTimes     map[string]int
-	RequestCount     int
 	CommitDetail     *util.CommitDetails
 	LockKeysDetail   *util.LockKeysDetails
 	ScanDetail       *util.ScanDetail
+	BackoffSleep     map[string]time.Duration
+	BackoffTimes     map[string]int
+	CalleeAddress    string
 	TimeDetail       util.TimeDetail
+	RequestCount     int
+	CopTime          time.Duration
+	BackoffTime      time.Duration
+	LockKeysDuration time.Duration
 }
 
 type stmtExecDetailKeyType struct{}
@@ -318,9 +318,9 @@ func (d ExecDetails) ToZapFields() (fields []zap.Field) {
 }
 
 type basicCopRuntimeStats struct {
-	BasicRuntimeStats
-	threads   int32
 	storeType string
+	BasicRuntimeStats
+	threads int32
 }
 
 // String implements the RuntimeStats interface.
@@ -359,8 +359,6 @@ func (*basicCopRuntimeStats) Tp() int {
 
 // CopRuntimeStats collects cop tasks' execution info.
 type CopRuntimeStats struct {
-	sync.Mutex
-
 	// stats stores the runtime statistics of coprocessor tasks.
 	// The key of the map is the tikv-server address. Because a tikv-server can
 	// have many region leaders, several coprocessor tasks can be sent to the
@@ -370,28 +368,30 @@ type CopRuntimeStats struct {
 	scanDetail *util.ScanDetail
 	// do not use kv.StoreType because it will meet cycle import error
 	storeType string
+	// count CopRuntimeStats total rows
+	totalRows int64
+	sync.Mutex
 }
 
 // RecordOneCopTask records a specific cop tasks's execution detail.
 func (crs *CopRuntimeStats) RecordOneCopTask(address string, summary *tipb.ExecutorExecutionSummary) {
 	crs.Lock()
 	defer crs.Unlock()
+	currentRows := int64(*summary.NumProducedRows)
+	crs.totalRows += currentRows
 	crs.stats[address] = append(crs.stats[address],
 		&basicCopRuntimeStats{BasicRuntimeStats: BasicRuntimeStats{loop: int32(*summary.NumIterations),
 			consume: int64(*summary.TimeProcessedNs),
-			rows:    int64(*summary.NumProducedRows)},
+			rows:    currentRows},
 			threads:   int32(summary.GetConcurrency()),
 			storeType: crs.storeType})
 }
 
 // GetActRows return total rows of CopRuntimeStats.
 func (crs *CopRuntimeStats) GetActRows() (totalRows int64) {
-	for _, instanceStats := range crs.stats {
-		for _, stat := range instanceStats {
-			totalRows += stat.rows
-		}
-	}
-	return totalRows
+	crs.Lock()
+	defer crs.Unlock()
+	return crs.totalRows
 }
 
 // MergeBasicStats traverses basicCopRuntimeStats in the CopRuntimeStats and collects some useful information.
@@ -635,9 +635,9 @@ func (e *BasicRuntimeStats) GetTime() int64 {
 
 // RuntimeStatsColl collects executors's execution info.
 type RuntimeStatsColl struct {
-	mu        sync.Mutex
 	rootStats map[int]*RootRuntimeStats
 	copStats  map[int]*CopRuntimeStats
+	mu        sync.Mutex
 }
 
 // NewRuntimeStatsColl creates new executor collector.
@@ -786,10 +786,8 @@ func NewConcurrencyInfo(name string, num int) *ConcurrencyInfo {
 
 // RuntimeStatsWithConcurrencyInfo is the BasicRuntimeStats with ConcurrencyInfo.
 type RuntimeStatsWithConcurrencyInfo struct {
-	// protect concurrency
-	sync.Mutex
-	// executor concurrency information
 	concurrency []*ConcurrencyInfo
+	sync.Mutex
 }
 
 // Tp implements the RuntimeStats interface.
@@ -840,8 +838,8 @@ func (*RuntimeStatsWithConcurrencyInfo) Merge(RuntimeStats) {}
 // RuntimeStatsWithCommit is the RuntimeStats with commit detail.
 type RuntimeStatsWithCommit struct {
 	Commit   *util.CommitDetails
-	TxnCnt   int
 	LockKeys *util.LockKeysDetails
+	TxnCnt   int
 }
 
 // Tp implements the RuntimeStats interface.

util/memory/tracker.go

@@ -563,6 +563,20 @@ func (t *Tracker) SearchTrackerWithoutLock(label int) *Tracker {
 	return nil
 }
 
+// SearchTrackerWithLock searches the specific tracker under this tracker with lock.
+func (t *Tracker) SearchTrackerWithLock(label int) *Tracker {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	if t.label == label {
+		return t
+	}
+	children := t.mu.children[label]
+	if len(children) > 0 {
+		return children[0]
+	}
+	return nil
+}
+
 // SearchTrackerConsumedMoreThanNBytes searches the specific tracker that consumes more than NBytes.
 func (t *Tracker) SearchTrackerConsumedMoreThanNBytes(limit int64) (res []*Tracker) {
 	t.mu.Lock()