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-rw-r--r--src/runtime/map_test.go1236
1 files changed, 1236 insertions, 0 deletions
diff --git a/src/runtime/map_test.go b/src/runtime/map_test.go
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+++ b/src/runtime/map_test.go
@@ -0,0 +1,1236 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package runtime_test
+
+import (
+ "fmt"
+ "internal/goarch"
+ "math"
+ "reflect"
+ "runtime"
+ "sort"
+ "strconv"
+ "strings"
+ "sync"
+ "testing"
+)
+
+func TestHmapSize(t *testing.T) {
+ // The structure of hmap is defined in runtime/map.go
+ // and in cmd/compile/internal/gc/reflect.go and must be in sync.
+ // The size of hmap should be 48 bytes on 64 bit and 28 bytes on 32 bit platforms.
+ var hmapSize = uintptr(8 + 5*goarch.PtrSize)
+ if runtime.RuntimeHmapSize != hmapSize {
+ t.Errorf("sizeof(runtime.hmap{})==%d, want %d", runtime.RuntimeHmapSize, hmapSize)
+ }
+
+}
+
+// negative zero is a good test because:
+// 1. 0 and -0 are equal, yet have distinct representations.
+// 2. 0 is represented as all zeros, -0 isn't.
+//
+// I'm not sure the language spec actually requires this behavior,
+// but it's what the current map implementation does.
+func TestNegativeZero(t *testing.T) {
+ m := make(map[float64]bool, 0)
+
+ m[+0.0] = true
+ m[math.Copysign(0.0, -1.0)] = true // should overwrite +0 entry
+
+ if len(m) != 1 {
+ t.Error("length wrong")
+ }
+
+ for k := range m {
+ if math.Copysign(1.0, k) > 0 {
+ t.Error("wrong sign")
+ }
+ }
+
+ m = make(map[float64]bool, 0)
+ m[math.Copysign(0.0, -1.0)] = true
+ m[+0.0] = true // should overwrite -0.0 entry
+
+ if len(m) != 1 {
+ t.Error("length wrong")
+ }
+
+ for k := range m {
+ if math.Copysign(1.0, k) < 0 {
+ t.Error("wrong sign")
+ }
+ }
+}
+
+func testMapNan(t *testing.T, m map[float64]int) {
+ if len(m) != 3 {
+ t.Error("length wrong")
+ }
+ s := 0
+ for k, v := range m {
+ if k == k {
+ t.Error("nan disappeared")
+ }
+ if (v & (v - 1)) != 0 {
+ t.Error("value wrong")
+ }
+ s |= v
+ }
+ if s != 7 {
+ t.Error("values wrong")
+ }
+}
+
+// nan is a good test because nan != nan, and nan has
+// a randomized hash value.
+func TestMapAssignmentNan(t *testing.T) {
+ m := make(map[float64]int, 0)
+ nan := math.NaN()
+
+ // Test assignment.
+ m[nan] = 1
+ m[nan] = 2
+ m[nan] = 4
+ testMapNan(t, m)
+}
+
+// nan is a good test because nan != nan, and nan has
+// a randomized hash value.
+func TestMapOperatorAssignmentNan(t *testing.T) {
+ m := make(map[float64]int, 0)
+ nan := math.NaN()
+
+ // Test assignment operations.
+ m[nan] += 1
+ m[nan] += 2
+ m[nan] += 4
+ testMapNan(t, m)
+}
+
+func TestMapOperatorAssignment(t *testing.T) {
+ m := make(map[int]int, 0)
+
+ // "m[k] op= x" is rewritten into "m[k] = m[k] op x"
+ // differently when op is / or % than when it isn't.
+ // Simple test to make sure they all work as expected.
+ m[0] = 12345
+ m[0] += 67890
+ m[0] /= 123
+ m[0] %= 456
+
+ const want = (12345 + 67890) / 123 % 456
+ if got := m[0]; got != want {
+ t.Errorf("got %d, want %d", got, want)
+ }
+}
+
+var sinkAppend bool
+
+func TestMapAppendAssignment(t *testing.T) {
+ m := make(map[int][]int, 0)
+
+ m[0] = nil
+ m[0] = append(m[0], 12345)
+ m[0] = append(m[0], 67890)
+ sinkAppend, m[0] = !sinkAppend, append(m[0], 123, 456)
+ a := []int{7, 8, 9, 0}
+ m[0] = append(m[0], a...)
+
+ want := []int{12345, 67890, 123, 456, 7, 8, 9, 0}
+ if got := m[0]; !reflect.DeepEqual(got, want) {
+ t.Errorf("got %v, want %v", got, want)
+ }
+}
+
+// Maps aren't actually copied on assignment.
+func TestAlias(t *testing.T) {
+ m := make(map[int]int, 0)
+ m[0] = 5
+ n := m
+ n[0] = 6
+ if m[0] != 6 {
+ t.Error("alias didn't work")
+ }
+}
+
+func TestGrowWithNaN(t *testing.T) {
+ m := make(map[float64]int, 4)
+ nan := math.NaN()
+
+ // Use both assignment and assignment operations as they may
+ // behave differently.
+ m[nan] = 1
+ m[nan] = 2
+ m[nan] += 4
+
+ cnt := 0
+ s := 0
+ growflag := true
+ for k, v := range m {
+ if growflag {
+ // force a hashtable resize
+ for i := 0; i < 50; i++ {
+ m[float64(i)] = i
+ }
+ for i := 50; i < 100; i++ {
+ m[float64(i)] += i
+ }
+ growflag = false
+ }
+ if k != k {
+ cnt++
+ s |= v
+ }
+ }
+ if cnt != 3 {
+ t.Error("NaN keys lost during grow")
+ }
+ if s != 7 {
+ t.Error("NaN values lost during grow")
+ }
+}
+
+type FloatInt struct {
+ x float64
+ y int
+}
+
+func TestGrowWithNegativeZero(t *testing.T) {
+ negzero := math.Copysign(0.0, -1.0)
+ m := make(map[FloatInt]int, 4)
+ m[FloatInt{0.0, 0}] = 1
+ m[FloatInt{0.0, 1}] += 2
+ m[FloatInt{0.0, 2}] += 4
+ m[FloatInt{0.0, 3}] = 8
+ growflag := true
+ s := 0
+ cnt := 0
+ negcnt := 0
+ // The first iteration should return the +0 key.
+ // The subsequent iterations should return the -0 key.
+ // I'm not really sure this is required by the spec,
+ // but it makes sense.
+ // TODO: are we allowed to get the first entry returned again???
+ for k, v := range m {
+ if v == 0 {
+ continue
+ } // ignore entries added to grow table
+ cnt++
+ if math.Copysign(1.0, k.x) < 0 {
+ if v&16 == 0 {
+ t.Error("key/value not updated together 1")
+ }
+ negcnt++
+ s |= v & 15
+ } else {
+ if v&16 == 16 {
+ t.Error("key/value not updated together 2", k, v)
+ }
+ s |= v
+ }
+ if growflag {
+ // force a hashtable resize
+ for i := 0; i < 100; i++ {
+ m[FloatInt{3.0, i}] = 0
+ }
+ // then change all the entries
+ // to negative zero
+ m[FloatInt{negzero, 0}] = 1 | 16
+ m[FloatInt{negzero, 1}] = 2 | 16
+ m[FloatInt{negzero, 2}] = 4 | 16
+ m[FloatInt{negzero, 3}] = 8 | 16
+ growflag = false
+ }
+ }
+ if s != 15 {
+ t.Error("entry missing", s)
+ }
+ if cnt != 4 {
+ t.Error("wrong number of entries returned by iterator", cnt)
+ }
+ if negcnt != 3 {
+ t.Error("update to negzero missed by iteration", negcnt)
+ }
+}
+
+func TestIterGrowAndDelete(t *testing.T) {
+ m := make(map[int]int, 4)
+ for i := 0; i < 100; i++ {
+ m[i] = i
+ }
+ growflag := true
+ for k := range m {
+ if growflag {
+ // grow the table
+ for i := 100; i < 1000; i++ {
+ m[i] = i
+ }
+ // delete all odd keys
+ for i := 1; i < 1000; i += 2 {
+ delete(m, i)
+ }
+ growflag = false
+ } else {
+ if k&1 == 1 {
+ t.Error("odd value returned")
+ }
+ }
+ }
+}
+
+// make sure old bucket arrays don't get GCd while
+// an iterator is still using them.
+func TestIterGrowWithGC(t *testing.T) {
+ m := make(map[int]int, 4)
+ for i := 0; i < 8; i++ {
+ m[i] = i
+ }
+ for i := 8; i < 16; i++ {
+ m[i] += i
+ }
+ growflag := true
+ bitmask := 0
+ for k := range m {
+ if k < 16 {
+ bitmask |= 1 << uint(k)
+ }
+ if growflag {
+ // grow the table
+ for i := 100; i < 1000; i++ {
+ m[i] = i
+ }
+ // trigger a gc
+ runtime.GC()
+ growflag = false
+ }
+ }
+ if bitmask != 1<<16-1 {
+ t.Error("missing key", bitmask)
+ }
+}
+
+func testConcurrentReadsAfterGrowth(t *testing.T, useReflect bool) {
+ t.Parallel()
+ if runtime.GOMAXPROCS(-1) == 1 {
+ defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(16))
+ }
+ numLoop := 10
+ numGrowStep := 250
+ numReader := 16
+ if testing.Short() {
+ numLoop, numGrowStep = 2, 100
+ }
+ for i := 0; i < numLoop; i++ {
+ m := make(map[int]int, 0)
+ for gs := 0; gs < numGrowStep; gs++ {
+ m[gs] = gs
+ var wg sync.WaitGroup
+ wg.Add(numReader * 2)
+ for nr := 0; nr < numReader; nr++ {
+ go func() {
+ defer wg.Done()
+ for range m {
+ }
+ }()
+ go func() {
+ defer wg.Done()
+ for key := 0; key < gs; key++ {
+ _ = m[key]
+ }
+ }()
+ if useReflect {
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+ mv := reflect.ValueOf(m)
+ keys := mv.MapKeys()
+ for _, k := range keys {
+ mv.MapIndex(k)
+ }
+ }()
+ }
+ }
+ wg.Wait()
+ }
+ }
+}
+
+func TestConcurrentReadsAfterGrowth(t *testing.T) {
+ testConcurrentReadsAfterGrowth(t, false)
+}
+
+func TestConcurrentReadsAfterGrowthReflect(t *testing.T) {
+ testConcurrentReadsAfterGrowth(t, true)
+}
+
+func TestBigItems(t *testing.T) {
+ var key [256]string
+ for i := 0; i < 256; i++ {
+ key[i] = "foo"
+ }
+ m := make(map[[256]string][256]string, 4)
+ for i := 0; i < 100; i++ {
+ key[37] = fmt.Sprintf("string%02d", i)
+ m[key] = key
+ }
+ var keys [100]string
+ var values [100]string
+ i := 0
+ for k, v := range m {
+ keys[i] = k[37]
+ values[i] = v[37]
+ i++
+ }
+ sort.Strings(keys[:])
+ sort.Strings(values[:])
+ for i := 0; i < 100; i++ {
+ if keys[i] != fmt.Sprintf("string%02d", i) {
+ t.Errorf("#%d: missing key: %v", i, keys[i])
+ }
+ if values[i] != fmt.Sprintf("string%02d", i) {
+ t.Errorf("#%d: missing value: %v", i, values[i])
+ }
+ }
+}
+
+func TestMapHugeZero(t *testing.T) {
+ type T [4000]byte
+ m := map[int]T{}
+ x := m[0]
+ if x != (T{}) {
+ t.Errorf("map value not zero")
+ }
+ y, ok := m[0]
+ if ok {
+ t.Errorf("map value should be missing")
+ }
+ if y != (T{}) {
+ t.Errorf("map value not zero")
+ }
+}
+
+type empty struct {
+}
+
+func TestEmptyKeyAndValue(t *testing.T) {
+ a := make(map[int]empty, 4)
+ b := make(map[empty]int, 4)
+ c := make(map[empty]empty, 4)
+ a[0] = empty{}
+ b[empty{}] = 0
+ b[empty{}] = 1
+ c[empty{}] = empty{}
+
+ if len(a) != 1 {
+ t.Errorf("empty value insert problem")
+ }
+ if b[empty{}] != 1 {
+ t.Errorf("empty key returned wrong value")
+ }
+}
+
+// Tests a map with a single bucket, with same-lengthed short keys
+// ("quick keys") as well as long keys.
+func TestSingleBucketMapStringKeys_DupLen(t *testing.T) {
+ testMapLookups(t, map[string]string{
+ "x": "x1val",
+ "xx": "x2val",
+ "foo": "fooval",
+ "bar": "barval", // same key length as "foo"
+ "xxxx": "x4val",
+ strings.Repeat("x", 128): "longval1",
+ strings.Repeat("y", 128): "longval2",
+ })
+}
+
+// Tests a map with a single bucket, with all keys having different lengths.
+func TestSingleBucketMapStringKeys_NoDupLen(t *testing.T) {
+ testMapLookups(t, map[string]string{
+ "x": "x1val",
+ "xx": "x2val",
+ "foo": "fooval",
+ "xxxx": "x4val",
+ "xxxxx": "x5val",
+ "xxxxxx": "x6val",
+ strings.Repeat("x", 128): "longval",
+ })
+}
+
+func testMapLookups(t *testing.T, m map[string]string) {
+ for k, v := range m {
+ if m[k] != v {
+ t.Fatalf("m[%q] = %q; want %q", k, m[k], v)
+ }
+ }
+}
+
+// Tests whether the iterator returns the right elements when
+// started in the middle of a grow, when the keys are NaNs.
+func TestMapNanGrowIterator(t *testing.T) {
+ m := make(map[float64]int)
+ nan := math.NaN()
+ const nBuckets = 16
+ // To fill nBuckets buckets takes LOAD * nBuckets keys.
+ nKeys := int(nBuckets * runtime.HashLoad)
+
+ // Get map to full point with nan keys.
+ for i := 0; i < nKeys; i++ {
+ m[nan] = i
+ }
+ // Trigger grow
+ m[1.0] = 1
+ delete(m, 1.0)
+
+ // Run iterator
+ found := make(map[int]struct{})
+ for _, v := range m {
+ if v != -1 {
+ if _, repeat := found[v]; repeat {
+ t.Fatalf("repeat of value %d", v)
+ }
+ found[v] = struct{}{}
+ }
+ if len(found) == nKeys/2 {
+ // Halfway through iteration, finish grow.
+ for i := 0; i < nBuckets; i++ {
+ delete(m, 1.0)
+ }
+ }
+ }
+ if len(found) != nKeys {
+ t.Fatalf("missing value")
+ }
+}
+
+func TestMapIterOrder(t *testing.T) {
+ for _, n := range [...]int{3, 7, 9, 15} {
+ for i := 0; i < 1000; i++ {
+ // Make m be {0: true, 1: true, ..., n-1: true}.
+ m := make(map[int]bool)
+ for i := 0; i < n; i++ {
+ m[i] = true
+ }
+ // Check that iterating over the map produces at least two different orderings.
+ ord := func() []int {
+ var s []int
+ for key := range m {
+ s = append(s, key)
+ }
+ return s
+ }
+ first := ord()
+ ok := false
+ for try := 0; try < 100; try++ {
+ if !reflect.DeepEqual(first, ord()) {
+ ok = true
+ break
+ }
+ }
+ if !ok {
+ t.Errorf("Map with n=%d elements had consistent iteration order: %v", n, first)
+ break
+ }
+ }
+ }
+}
+
+// Issue 8410
+func TestMapSparseIterOrder(t *testing.T) {
+ // Run several rounds to increase the probability
+ // of failure. One is not enough.
+NextRound:
+ for round := 0; round < 10; round++ {
+ m := make(map[int]bool)
+ // Add 1000 items, remove 980.
+ for i := 0; i < 1000; i++ {
+ m[i] = true
+ }
+ for i := 20; i < 1000; i++ {
+ delete(m, i)
+ }
+
+ var first []int
+ for i := range m {
+ first = append(first, i)
+ }
+
+ // 800 chances to get a different iteration order.
+ // See bug 8736 for why we need so many tries.
+ for n := 0; n < 800; n++ {
+ idx := 0
+ for i := range m {
+ if i != first[idx] {
+ // iteration order changed.
+ continue NextRound
+ }
+ idx++
+ }
+ }
+ t.Fatalf("constant iteration order on round %d: %v", round, first)
+ }
+}
+
+func TestMapStringBytesLookup(t *testing.T) {
+ // Use large string keys to avoid small-allocation coalescing,
+ // which can cause AllocsPerRun to report lower counts than it should.
+ m := map[string]int{
+ "1000000000000000000000000000000000000000000000000": 1,
+ "2000000000000000000000000000000000000000000000000": 2,
+ }
+ buf := []byte("1000000000000000000000000000000000000000000000000")
+ if x := m[string(buf)]; x != 1 {
+ t.Errorf(`m[string([]byte("1"))] = %d, want 1`, x)
+ }
+ buf[0] = '2'
+ if x := m[string(buf)]; x != 2 {
+ t.Errorf(`m[string([]byte("2"))] = %d, want 2`, x)
+ }
+
+ var x int
+ n := testing.AllocsPerRun(100, func() {
+ x += m[string(buf)]
+ })
+ if n != 0 {
+ t.Errorf("AllocsPerRun for m[string(buf)] = %v, want 0", n)
+ }
+
+ x = 0
+ n = testing.AllocsPerRun(100, func() {
+ y, ok := m[string(buf)]
+ if !ok {
+ panic("!ok")
+ }
+ x += y
+ })
+ if n != 0 {
+ t.Errorf("AllocsPerRun for x,ok = m[string(buf)] = %v, want 0", n)
+ }
+}
+
+func TestMapLargeKeyNoPointer(t *testing.T) {
+ const (
+ I = 1000
+ N = 64
+ )
+ type T [N]int
+ m := make(map[T]int)
+ for i := 0; i < I; i++ {
+ var v T
+ for j := 0; j < N; j++ {
+ v[j] = i + j
+ }
+ m[v] = i
+ }
+ runtime.GC()
+ for i := 0; i < I; i++ {
+ var v T
+ for j := 0; j < N; j++ {
+ v[j] = i + j
+ }
+ if m[v] != i {
+ t.Fatalf("corrupted map: want %+v, got %+v", i, m[v])
+ }
+ }
+}
+
+func TestMapLargeValNoPointer(t *testing.T) {
+ const (
+ I = 1000
+ N = 64
+ )
+ type T [N]int
+ m := make(map[int]T)
+ for i := 0; i < I; i++ {
+ var v T
+ for j := 0; j < N; j++ {
+ v[j] = i + j
+ }
+ m[i] = v
+ }
+ runtime.GC()
+ for i := 0; i < I; i++ {
+ var v T
+ for j := 0; j < N; j++ {
+ v[j] = i + j
+ }
+ v1 := m[i]
+ for j := 0; j < N; j++ {
+ if v1[j] != v[j] {
+ t.Fatalf("corrupted map: want %+v, got %+v", v, v1)
+ }
+ }
+ }
+}
+
+// Test that making a map with a large or invalid hint
+// doesn't panic. (Issue 19926).
+func TestIgnoreBogusMapHint(t *testing.T) {
+ for _, hint := range []int64{-1, 1 << 62} {
+ _ = make(map[int]int, hint)
+ }
+}
+
+var mapBucketTests = [...]struct {
+ n int // n is the number of map elements
+ noescape int // number of expected buckets for non-escaping map
+ escape int // number of expected buckets for escaping map
+}{
+ {-(1 << 30), 1, 1},
+ {-1, 1, 1},
+ {0, 1, 1},
+ {1, 1, 1},
+ {8, 1, 1},
+ {9, 2, 2},
+ {13, 2, 2},
+ {14, 4, 4},
+ {26, 4, 4},
+}
+
+func TestMapBuckets(t *testing.T) {
+ // Test that maps of different sizes have the right number of buckets.
+ // Non-escaping maps with small buckets (like map[int]int) never
+ // have a nil bucket pointer due to starting with preallocated buckets
+ // on the stack. Escaping maps start with a non-nil bucket pointer if
+ // hint size is above bucketCnt and thereby have more than one bucket.
+ // These tests depend on bucketCnt and loadFactor* in map.go.
+ t.Run("mapliteral", func(t *testing.T) {
+ for _, tt := range mapBucketTests {
+ localMap := map[int]int{}
+ if runtime.MapBucketsPointerIsNil(localMap) {
+ t.Errorf("no escape: buckets pointer is nil for non-escaping map")
+ }
+ for i := 0; i < tt.n; i++ {
+ localMap[i] = i
+ }
+ if got := runtime.MapBucketsCount(localMap); got != tt.noescape {
+ t.Errorf("no escape: n=%d want %d buckets, got %d", tt.n, tt.noescape, got)
+ }
+ escapingMap := runtime.Escape(map[int]int{})
+ if count := runtime.MapBucketsCount(escapingMap); count > 1 && runtime.MapBucketsPointerIsNil(escapingMap) {
+ t.Errorf("escape: buckets pointer is nil for n=%d buckets", count)
+ }
+ for i := 0; i < tt.n; i++ {
+ escapingMap[i] = i
+ }
+ if got := runtime.MapBucketsCount(escapingMap); got != tt.escape {
+ t.Errorf("escape n=%d want %d buckets, got %d", tt.n, tt.escape, got)
+ }
+ }
+ })
+ t.Run("nohint", func(t *testing.T) {
+ for _, tt := range mapBucketTests {
+ localMap := make(map[int]int)
+ if runtime.MapBucketsPointerIsNil(localMap) {
+ t.Errorf("no escape: buckets pointer is nil for non-escaping map")
+ }
+ for i := 0; i < tt.n; i++ {
+ localMap[i] = i
+ }
+ if got := runtime.MapBucketsCount(localMap); got != tt.noescape {
+ t.Errorf("no escape: n=%d want %d buckets, got %d", tt.n, tt.noescape, got)
+ }
+ escapingMap := runtime.Escape(make(map[int]int))
+ if count := runtime.MapBucketsCount(escapingMap); count > 1 && runtime.MapBucketsPointerIsNil(escapingMap) {
+ t.Errorf("escape: buckets pointer is nil for n=%d buckets", count)
+ }
+ for i := 0; i < tt.n; i++ {
+ escapingMap[i] = i
+ }
+ if got := runtime.MapBucketsCount(escapingMap); got != tt.escape {
+ t.Errorf("escape: n=%d want %d buckets, got %d", tt.n, tt.escape, got)
+ }
+ }
+ })
+ t.Run("makemap", func(t *testing.T) {
+ for _, tt := range mapBucketTests {
+ localMap := make(map[int]int, tt.n)
+ if runtime.MapBucketsPointerIsNil(localMap) {
+ t.Errorf("no escape: buckets pointer is nil for non-escaping map")
+ }
+ for i := 0; i < tt.n; i++ {
+ localMap[i] = i
+ }
+ if got := runtime.MapBucketsCount(localMap); got != tt.noescape {
+ t.Errorf("no escape: n=%d want %d buckets, got %d", tt.n, tt.noescape, got)
+ }
+ escapingMap := runtime.Escape(make(map[int]int, tt.n))
+ if count := runtime.MapBucketsCount(escapingMap); count > 1 && runtime.MapBucketsPointerIsNil(escapingMap) {
+ t.Errorf("escape: buckets pointer is nil for n=%d buckets", count)
+ }
+ for i := 0; i < tt.n; i++ {
+ escapingMap[i] = i
+ }
+ if got := runtime.MapBucketsCount(escapingMap); got != tt.escape {
+ t.Errorf("escape: n=%d want %d buckets, got %d", tt.n, tt.escape, got)
+ }
+ }
+ })
+ t.Run("makemap64", func(t *testing.T) {
+ for _, tt := range mapBucketTests {
+ localMap := make(map[int]int, int64(tt.n))
+ if runtime.MapBucketsPointerIsNil(localMap) {
+ t.Errorf("no escape: buckets pointer is nil for non-escaping map")
+ }
+ for i := 0; i < tt.n; i++ {
+ localMap[i] = i
+ }
+ if got := runtime.MapBucketsCount(localMap); got != tt.noescape {
+ t.Errorf("no escape: n=%d want %d buckets, got %d", tt.n, tt.noescape, got)
+ }
+ escapingMap := runtime.Escape(make(map[int]int, tt.n))
+ if count := runtime.MapBucketsCount(escapingMap); count > 1 && runtime.MapBucketsPointerIsNil(escapingMap) {
+ t.Errorf("escape: buckets pointer is nil for n=%d buckets", count)
+ }
+ for i := 0; i < tt.n; i++ {
+ escapingMap[i] = i
+ }
+ if got := runtime.MapBucketsCount(escapingMap); got != tt.escape {
+ t.Errorf("escape: n=%d want %d buckets, got %d", tt.n, tt.escape, got)
+ }
+ }
+ })
+
+}
+
+func benchmarkMapPop(b *testing.B, n int) {
+ m := map[int]int{}
+ for i := 0; i < b.N; i++ {
+ for j := 0; j < n; j++ {
+ m[j] = j
+ }
+ for j := 0; j < n; j++ {
+ // Use iterator to pop an element.
+ // We want this to be fast, see issue 8412.
+ for k := range m {
+ delete(m, k)
+ break
+ }
+ }
+ }
+}
+
+func BenchmarkMapPop100(b *testing.B) { benchmarkMapPop(b, 100) }
+func BenchmarkMapPop1000(b *testing.B) { benchmarkMapPop(b, 1000) }
+func BenchmarkMapPop10000(b *testing.B) { benchmarkMapPop(b, 10000) }
+
+var testNonEscapingMapVariable int = 8
+
+func TestNonEscapingMap(t *testing.T) {
+ n := testing.AllocsPerRun(1000, func() {
+ m := map[int]int{}
+ m[0] = 0
+ })
+ if n != 0 {
+ t.Fatalf("mapliteral: want 0 allocs, got %v", n)
+ }
+ n = testing.AllocsPerRun(1000, func() {
+ m := make(map[int]int)
+ m[0] = 0
+ })
+ if n != 0 {
+ t.Fatalf("no hint: want 0 allocs, got %v", n)
+ }
+ n = testing.AllocsPerRun(1000, func() {
+ m := make(map[int]int, 8)
+ m[0] = 0
+ })
+ if n != 0 {
+ t.Fatalf("with small hint: want 0 allocs, got %v", n)
+ }
+ n = testing.AllocsPerRun(1000, func() {
+ m := make(map[int]int, testNonEscapingMapVariable)
+ m[0] = 0
+ })
+ if n != 0 {
+ t.Fatalf("with variable hint: want 0 allocs, got %v", n)
+ }
+
+}
+
+func benchmarkMapAssignInt32(b *testing.B, n int) {
+ a := make(map[int32]int)
+ for i := 0; i < b.N; i++ {
+ a[int32(i&(n-1))] = i
+ }
+}
+
+func benchmarkMapOperatorAssignInt32(b *testing.B, n int) {
+ a := make(map[int32]int)
+ for i := 0; i < b.N; i++ {
+ a[int32(i&(n-1))] += i
+ }
+}
+
+func benchmarkMapAppendAssignInt32(b *testing.B, n int) {
+ a := make(map[int32][]int)
+ b.ReportAllocs()
+ b.ResetTimer()
+ for i := 0; i < b.N; i++ {
+ key := int32(i & (n - 1))
+ a[key] = append(a[key], i)
+ }
+}
+
+func benchmarkMapDeleteInt32(b *testing.B, n int) {
+ a := make(map[int32]int, n)
+ b.ResetTimer()
+ for i := 0; i < b.N; i++ {
+ if len(a) == 0 {
+ b.StopTimer()
+ for j := i; j < i+n; j++ {
+ a[int32(j)] = j
+ }
+ b.StartTimer()
+ }
+ delete(a, int32(i))
+ }
+}
+
+func benchmarkMapAssignInt64(b *testing.B, n int) {
+ a := make(map[int64]int)
+ for i := 0; i < b.N; i++ {
+ a[int64(i&(n-1))] = i
+ }
+}
+
+func benchmarkMapOperatorAssignInt64(b *testing.B, n int) {
+ a := make(map[int64]int)
+ for i := 0; i < b.N; i++ {
+ a[int64(i&(n-1))] += i
+ }
+}
+
+func benchmarkMapAppendAssignInt64(b *testing.B, n int) {
+ a := make(map[int64][]int)
+ b.ReportAllocs()
+ b.ResetTimer()
+ for i := 0; i < b.N; i++ {
+ key := int64(i & (n - 1))
+ a[key] = append(a[key], i)
+ }
+}
+
+func benchmarkMapDeleteInt64(b *testing.B, n int) {
+ a := make(map[int64]int, n)
+ b.ResetTimer()
+ for i := 0; i < b.N; i++ {
+ if len(a) == 0 {
+ b.StopTimer()
+ for j := i; j < i+n; j++ {
+ a[int64(j)] = j
+ }
+ b.StartTimer()
+ }
+ delete(a, int64(i))
+ }
+}
+
+func benchmarkMapAssignStr(b *testing.B, n int) {
+ k := make([]string, n)
+ for i := 0; i < len(k); i++ {
+ k[i] = strconv.Itoa(i)
+ }
+ b.ResetTimer()
+ a := make(map[string]int)
+ for i := 0; i < b.N; i++ {
+ a[k[i&(n-1)]] = i
+ }
+}
+
+func benchmarkMapOperatorAssignStr(b *testing.B, n int) {
+ k := make([]string, n)
+ for i := 0; i < len(k); i++ {
+ k[i] = strconv.Itoa(i)
+ }
+ b.ResetTimer()
+ a := make(map[string]string)
+ for i := 0; i < b.N; i++ {
+ key := k[i&(n-1)]
+ a[key] += key
+ }
+}
+
+func benchmarkMapAppendAssignStr(b *testing.B, n int) {
+ k := make([]string, n)
+ for i := 0; i < len(k); i++ {
+ k[i] = strconv.Itoa(i)
+ }
+ a := make(map[string][]string)
+ b.ReportAllocs()
+ b.ResetTimer()
+ for i := 0; i < b.N; i++ {
+ key := k[i&(n-1)]
+ a[key] = append(a[key], key)
+ }
+}
+
+func benchmarkMapDeleteStr(b *testing.B, n int) {
+ i2s := make([]string, n)
+ for i := 0; i < n; i++ {
+ i2s[i] = strconv.Itoa(i)
+ }
+ a := make(map[string]int, n)
+ b.ResetTimer()
+ k := 0
+ for i := 0; i < b.N; i++ {
+ if len(a) == 0 {
+ b.StopTimer()
+ for j := 0; j < n; j++ {
+ a[i2s[j]] = j
+ }
+ k = i
+ b.StartTimer()
+ }
+ delete(a, i2s[i-k])
+ }
+}
+
+func benchmarkMapDeletePointer(b *testing.B, n int) {
+ i2p := make([]*int, n)
+ for i := 0; i < n; i++ {
+ i2p[i] = new(int)
+ }
+ a := make(map[*int]int, n)
+ b.ResetTimer()
+ k := 0
+ for i := 0; i < b.N; i++ {
+ if len(a) == 0 {
+ b.StopTimer()
+ for j := 0; j < n; j++ {
+ a[i2p[j]] = j
+ }
+ k = i
+ b.StartTimer()
+ }
+ delete(a, i2p[i-k])
+ }
+}
+
+func runWith(f func(*testing.B, int), v ...int) func(*testing.B) {
+ return func(b *testing.B) {
+ for _, n := range v {
+ b.Run(strconv.Itoa(n), func(b *testing.B) { f(b, n) })
+ }
+ }
+}
+
+func BenchmarkMapAssign(b *testing.B) {
+ b.Run("Int32", runWith(benchmarkMapAssignInt32, 1<<8, 1<<16))
+ b.Run("Int64", runWith(benchmarkMapAssignInt64, 1<<8, 1<<16))
+ b.Run("Str", runWith(benchmarkMapAssignStr, 1<<8, 1<<16))
+}
+
+func BenchmarkMapOperatorAssign(b *testing.B) {
+ b.Run("Int32", runWith(benchmarkMapOperatorAssignInt32, 1<<8, 1<<16))
+ b.Run("Int64", runWith(benchmarkMapOperatorAssignInt64, 1<<8, 1<<16))
+ b.Run("Str", runWith(benchmarkMapOperatorAssignStr, 1<<8, 1<<16))
+}
+
+func BenchmarkMapAppendAssign(b *testing.B) {
+ b.Run("Int32", runWith(benchmarkMapAppendAssignInt32, 1<<8, 1<<16))
+ b.Run("Int64", runWith(benchmarkMapAppendAssignInt64, 1<<8, 1<<16))
+ b.Run("Str", runWith(benchmarkMapAppendAssignStr, 1<<8, 1<<16))
+}
+
+func BenchmarkMapDelete(b *testing.B) {
+ b.Run("Int32", runWith(benchmarkMapDeleteInt32, 100, 1000, 10000))
+ b.Run("Int64", runWith(benchmarkMapDeleteInt64, 100, 1000, 10000))
+ b.Run("Str", runWith(benchmarkMapDeleteStr, 100, 1000, 10000))
+ b.Run("Pointer", runWith(benchmarkMapDeletePointer, 100, 1000, 10000))
+}
+
+func TestDeferDeleteSlow(t *testing.T) {
+ ks := []complex128{0, 1, 2, 3}
+
+ m := make(map[any]int)
+ for i, k := range ks {
+ m[k] = i
+ }
+ if len(m) != len(ks) {
+ t.Errorf("want %d elements, got %d", len(ks), len(m))
+ }
+
+ func() {
+ for _, k := range ks {
+ defer delete(m, k)
+ }
+ }()
+ if len(m) != 0 {
+ t.Errorf("want 0 elements, got %d", len(m))
+ }
+}
+
+// TestIncrementAfterDeleteValueInt and other test Issue 25936.
+// Value types int, int32, int64 are affected. Value type string
+// works as expected.
+func TestIncrementAfterDeleteValueInt(t *testing.T) {
+ const key1 = 12
+ const key2 = 13
+
+ m := make(map[int]int)
+ m[key1] = 99
+ delete(m, key1)
+ m[key2]++
+ if n2 := m[key2]; n2 != 1 {
+ t.Errorf("incremented 0 to %d", n2)
+ }
+}
+
+func TestIncrementAfterDeleteValueInt32(t *testing.T) {
+ const key1 = 12
+ const key2 = 13
+
+ m := make(map[int]int32)
+ m[key1] = 99
+ delete(m, key1)
+ m[key2]++
+ if n2 := m[key2]; n2 != 1 {
+ t.Errorf("incremented 0 to %d", n2)
+ }
+}
+
+func TestIncrementAfterDeleteValueInt64(t *testing.T) {
+ const key1 = 12
+ const key2 = 13
+
+ m := make(map[int]int64)
+ m[key1] = 99
+ delete(m, key1)
+ m[key2]++
+ if n2 := m[key2]; n2 != 1 {
+ t.Errorf("incremented 0 to %d", n2)
+ }
+}
+
+func TestIncrementAfterDeleteKeyStringValueInt(t *testing.T) {
+ const key1 = ""
+ const key2 = "x"
+
+ m := make(map[string]int)
+ m[key1] = 99
+ delete(m, key1)
+ m[key2] += 1
+ if n2 := m[key2]; n2 != 1 {
+ t.Errorf("incremented 0 to %d", n2)
+ }
+}
+
+func TestIncrementAfterDeleteKeyValueString(t *testing.T) {
+ const key1 = ""
+ const key2 = "x"
+
+ m := make(map[string]string)
+ m[key1] = "99"
+ delete(m, key1)
+ m[key2] += "1"
+ if n2 := m[key2]; n2 != "1" {
+ t.Errorf("appended '1' to empty (nil) string, got %s", n2)
+ }
+}
+
+// TestIncrementAfterBulkClearKeyStringValueInt tests that map bulk
+// deletion (mapclear) still works as expected. Note that it was not
+// affected by Issue 25936.
+func TestIncrementAfterBulkClearKeyStringValueInt(t *testing.T) {
+ const key1 = ""
+ const key2 = "x"
+
+ m := make(map[string]int)
+ m[key1] = 99
+ for k := range m {
+ delete(m, k)
+ }
+ m[key2]++
+ if n2 := m[key2]; n2 != 1 {
+ t.Errorf("incremented 0 to %d", n2)
+ }
+}
+
+func TestMapTombstones(t *testing.T) {
+ m := map[int]int{}
+ const N = 10000
+ // Fill a map.
+ for i := 0; i < N; i++ {
+ m[i] = i
+ }
+ runtime.MapTombstoneCheck(m)
+ // Delete half of the entries.
+ for i := 0; i < N; i += 2 {
+ delete(m, i)
+ }
+ runtime.MapTombstoneCheck(m)
+ // Add new entries to fill in holes.
+ for i := N; i < 3*N/2; i++ {
+ m[i] = i
+ }
+ runtime.MapTombstoneCheck(m)
+ // Delete everything.
+ for i := 0; i < 3*N/2; i++ {
+ delete(m, i)
+ }
+ runtime.MapTombstoneCheck(m)
+}
+
+type canString int
+
+func (c canString) String() string {
+ return fmt.Sprintf("%d", int(c))
+}
+
+func TestMapInterfaceKey(t *testing.T) {
+ // Test all the special cases in runtime.typehash.
+ type GrabBag struct {
+ f32 float32
+ f64 float64
+ c64 complex64
+ c128 complex128
+ s string
+ i0 any
+ i1 interface {
+ String() string
+ }
+ a [4]string
+ }
+
+ m := map[any]bool{}
+ // Put a bunch of data in m, so that a bad hash is likely to
+ // lead to a bad bucket, which will lead to a missed lookup.
+ for i := 0; i < 1000; i++ {
+ m[i] = true
+ }
+ m[GrabBag{f32: 1.0}] = true
+ if !m[GrabBag{f32: 1.0}] {
+ panic("f32 not found")
+ }
+ m[GrabBag{f64: 1.0}] = true
+ if !m[GrabBag{f64: 1.0}] {
+ panic("f64 not found")
+ }
+ m[GrabBag{c64: 1.0i}] = true
+ if !m[GrabBag{c64: 1.0i}] {
+ panic("c64 not found")
+ }
+ m[GrabBag{c128: 1.0i}] = true
+ if !m[GrabBag{c128: 1.0i}] {
+ panic("c128 not found")
+ }
+ m[GrabBag{s: "foo"}] = true
+ if !m[GrabBag{s: "foo"}] {
+ panic("string not found")
+ }
+ m[GrabBag{i0: "foo"}] = true
+ if !m[GrabBag{i0: "foo"}] {
+ panic("interface{} not found")
+ }
+ m[GrabBag{i1: canString(5)}] = true
+ if !m[GrabBag{i1: canString(5)}] {
+ panic("interface{String() string} not found")
+ }
+ m[GrabBag{a: [4]string{"foo", "bar", "baz", "bop"}}] = true
+ if !m[GrabBag{a: [4]string{"foo", "bar", "baz", "bop"}}] {
+ panic("array not found")
+ }
+}