From 70c8038649067ba086211d4b212e7b9b674eb9df Mon Sep 17 00:00:00 2001
From: Vicent Marti <vmg@strn.cat>
Date: Tue, 2 Feb 2021 11:26:59 +0100
Subject: [PATCH] cache: speed up clearing large caches

Signed-off-by: Vicent Marti <vmg@strn.cat>
---
 go/cache/ristretto/policy.go              | 30 +++++++++++++----------
 go/vt/vtgate/executor_vschema_ddl_test.go |  8 +++---
 2 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/go/cache/ristretto/policy.go b/go/cache/ristretto/policy.go
index aa3c0b8c26b..b20b903309c 100644
--- a/go/cache/ristretto/policy.go
+++ b/go/cache/ristretto/policy.go
@@ -68,20 +68,24 @@ func newPolicy(numCounters, maxCost int64) policy {
 
 type defaultPolicy struct {
 	sync.Mutex
-	admit    *tinyLFU
-	evict    *sampledLFU
-	itemsCh  chan []uint64
-	stop     chan struct{}
-	isClosed bool
-	metrics  *Metrics
+	admit       *tinyLFU
+	evict       *sampledLFU
+	itemsCh     chan []uint64
+	stop        chan struct{}
+	isClosed    bool
+	metrics     *Metrics
+	numCounters int64
+	maxCost     int64
 }
 
 func newDefaultPolicy(numCounters, maxCost int64) *defaultPolicy {
 	p := &defaultPolicy{
-		admit:   newTinyLFU(numCounters),
-		evict:   newSampledLFU(maxCost),
-		itemsCh: make(chan []uint64, 3),
-		stop:    make(chan struct{}),
+		admit:       newTinyLFU(numCounters),
+		evict:       newSampledLFU(maxCost),
+		itemsCh:     make(chan []uint64, 3),
+		stop:        make(chan struct{}),
+		numCounters: numCounters,
+		maxCost:     maxCost,
 	}
 	go p.processItems()
 	return p
@@ -246,8 +250,8 @@ func (p *defaultPolicy) Cost(key uint64) int64 {
 
 func (p *defaultPolicy) Clear() {
 	p.Lock()
-	p.admit.clear()
-	p.evict.clear()
+	p.admit = newTinyLFU(p.numCounters)
+	p.evict = newSampledLFU(p.maxCost)
 	p.Unlock()
 }
 
@@ -412,6 +416,6 @@ func (p *tinyLFU) reset() {
 
 func (p *tinyLFU) clear() {
 	p.incrs = 0
-	p.door.Clear()
 	p.freq.Clear()
+	p.door.Clear()
 }
diff --git a/go/vt/vtgate/executor_vschema_ddl_test.go b/go/vt/vtgate/executor_vschema_ddl_test.go
index b6346761cbe..2e974c47cdb 100644
--- a/go/vt/vtgate/executor_vschema_ddl_test.go
+++ b/go/vt/vtgate/executor_vschema_ddl_test.go
@@ -58,14 +58,14 @@ func waitForVindex(t *testing.T, ks, name string, watch chan *vschemapb.SrvVSche
 		t.Errorf("vschema was not updated as expected")
 	}
 
-	// Wait up to 10ms until the vindex manager gets notified of the update
+	// Wait up to 100ms until the vindex manager gets notified of the update
 	for i := 0; i < 10; i++ {
 		vschema := executor.vm.GetCurrentSrvVschema()
 		vindex, ok := vschema.Keyspaces[ks].Vindexes[name]
 		if ok {
 			return vschema, vindex
 		}
-		time.Sleep(time.Millisecond)
+		time.Sleep(10 * time.Millisecond)
 	}
 
 	t.Fatalf("updated vschema did not contain %s", name)
@@ -75,7 +75,7 @@ func waitForVindex(t *testing.T, ks, name string, watch chan *vschemapb.SrvVSche
 func waitForVschemaTables(t *testing.T, ks string, tables []string, executor *Executor) *vschemapb.SrvVSchema {
 	t.Helper()
 
-	// Wait up to 10ms until the vindex manager gets notified of the update
+	// Wait up to 100ms until the vindex manager gets notified of the update
 	for i := 0; i < 10; i++ {
 		vschema := executor.vm.GetCurrentSrvVschema()
 		gotTables := []string{}
@@ -87,7 +87,7 @@ func waitForVschemaTables(t *testing.T, ks string, tables []string, executor *Ex
 		if reflect.DeepEqual(tables, gotTables) {
 			return vschema
 		}
-		time.Sleep(time.Millisecond)
+		time.Sleep(10 * time.Millisecond)
 	}
 
 	t.Fatalf("updated vschema did not contain tables %v", tables)