syncmap: make quick-check output more readable
Add a test for Range with concurrent Loads and Stores.
The previous quick-check tests generated long, mostly-non-ASCII
strings that were hard to debug on failure; this change makes the keys
and values short and human-readable, which also tends to produce more
key collisions in the test as a side-effect.
updates golang/go#18177
Change-Id: Ie56a64ec9fe295435682b90c3e6466ed5b349bf9
Reviewed-on: https://go-review.googlesource.com/37150
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/syncmap/map_test.go b/syncmap/map_test.go
index 54448a0..a60bbed 100644
--- a/syncmap/map_test.go
+++ b/syncmap/map_test.go
@@ -5,20 +5,48 @@
package syncmap_test
import (
- "fmt"
"math/rand"
"reflect"
+ "runtime"
+ "sync"
"testing"
"testing/quick"
"golang.org/x/sync/syncmap"
)
+type mapOp string
+
+const (
+ opLoad = mapOp("Load")
+ opStore = mapOp("Store")
+ opLoadOrStore = mapOp("LoadOrStore")
+ opDelete = mapOp("Delete")
+)
+
+var mapOps = [...]mapOp{opLoad, opStore, opLoadOrStore, opDelete}
+
// mapCall is a quick.Generator for calls on mapInterface.
type mapCall struct {
- key interface{}
- apply func(mapInterface) (interface{}, bool)
- desc string
+ op mapOp
+ k, v interface{}
+}
+
+func (c mapCall) apply(m mapInterface) (interface{}, bool) {
+ switch c.op {
+ case opLoad:
+ return m.Load(c.k)
+ case opStore:
+ m.Store(c.k, c.v)
+ return nil, false
+ case opLoadOrStore:
+ return m.LoadOrStore(c.k, c.v)
+ case opDelete:
+ m.Delete(c.k)
+ return nil, false
+ default:
+ panic("invalid mapOp")
+ }
}
type mapResult struct {
@@ -26,54 +54,21 @@
ok bool
}
-var stringType = reflect.TypeOf("")
-
func randValue(r *rand.Rand) interface{} {
- k, ok := quick.Value(stringType, r)
- if !ok {
- panic(fmt.Sprintf("quick.Value(%v, _) failed", stringType))
+ b := make([]byte, r.Intn(4))
+ for i := range b {
+ b[i] = 'a' + byte(rand.Intn(26))
}
- return k.Interface()
+ return string(b)
}
func (mapCall) Generate(r *rand.Rand, size int) reflect.Value {
- k := randValue(r)
-
- var (
- app func(mapInterface) (interface{}, bool)
- desc string
- )
- switch rand.Intn(4) {
- case 0:
- app = func(m mapInterface) (interface{}, bool) {
- return m.Load(k)
- }
- desc = fmt.Sprintf("Load(%q)", k)
-
- case 1:
- v := randValue(r)
- app = func(m mapInterface) (interface{}, bool) {
- m.Store(k, v)
- return nil, false
- }
- desc = fmt.Sprintf("Store(%q, %q)", k, v)
-
- case 2:
- v := randValue(r)
- app = func(m mapInterface) (interface{}, bool) {
- return m.LoadOrStore(k, v)
- }
- desc = fmt.Sprintf("LoadOrStore(%q, %q)", k, v)
-
- case 3:
- app = func(m mapInterface) (interface{}, bool) {
- m.Delete(k)
- return nil, false
- }
- desc = fmt.Sprintf("Delete(%q)", k)
+ c := mapCall{op: mapOps[rand.Intn(len(mapOps))], k: randValue(r)}
+ switch c.op {
+ case opStore, opLoadOrStore:
+ c.v = randValue(r)
}
-
- return reflect.ValueOf(mapCall{k, app, desc})
+ return reflect.ValueOf(c)
}
func applyCalls(m mapInterface, calls []mapCall) (results []mapResult, final map[interface{}]interface{}) {
@@ -114,3 +109,64 @@
t.Error(err)
}
}
+
+func TestConcurrentRange(t *testing.T) {
+ const mapSize = 1 << 10
+
+ m := new(syncmap.Map)
+ for n := int64(1); n <= mapSize; n++ {
+ m.Store(n, int64(n))
+ }
+
+ done := make(chan struct{})
+ var wg sync.WaitGroup
+ defer func() {
+ close(done)
+ wg.Wait()
+ }()
+ for g := int64(runtime.GOMAXPROCS(0)); g > 0; g-- {
+ r := rand.New(rand.NewSource(g))
+ wg.Add(1)
+ go func(g int64) {
+ defer wg.Done()
+ for i := int64(0); ; i++ {
+ select {
+ case <-done:
+ return
+ default:
+ }
+ for n := int64(1); n < mapSize; n++ {
+ if r.Int63n(mapSize) == 0 {
+ m.Store(n, n*i*g)
+ } else {
+ m.Load(n)
+ }
+ }
+ }
+ }(g)
+ }
+
+ iters := 1 << 10
+ if testing.Short() {
+ iters = 16
+ }
+ for n := iters; n > 0; n-- {
+ seen := make(map[int64]bool, mapSize)
+
+ m.Range(func(ki, vi interface{}) bool {
+ k, v := ki.(int64), vi.(int64)
+ if v%k != 0 {
+ t.Fatalf("while Storing multiples of %v, Range saw value %v", k, v)
+ }
+ if seen[k] {
+ t.Fatalf("Range visited key %v twice", k)
+ }
+ seen[k] = true
+ return true
+ })
+
+ if len(seen) != mapSize {
+ t.Fatalf("Range visited %v elements of %v-element Map", len(seen), mapSize)
+ }
+ }
+}
