* README.Portability: Remove note on an Irix compatibility issue.

[official-gcc.git] / libgo / go / runtime / map_test.go

// 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"
        "math"
        "reflect"
        "runtime"
        "sort"
        "strings"
        "sync"
        "testing"
)

// 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")
                }
        }
}

// nan is a good test because nan != nan, and nan has
// a randomized hash value.
func TestNan(t *testing.T) {
        m := make(map[float64]int, 0)
        nan := math.NaN()
        m[nan] = 1
        m[nan] = 2
        m[nan] = 4
        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")
        }
}

// 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()
        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 < 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 < 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 {
                if runtime.GOARCH == "s390" {
                        // Test uses too much address space on 31-bit S390.
                        defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(8))
                } else {
                        defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(16))
                }
        }
        numLoop := 10
        numGrowStep := 250
        numReader := 16
        if testing.Short() {
                numLoop, numGrowStep = 2, 500
        }
        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)
        }

        t.Skip("does not work on gccgo without better escape analysis")

        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)
                        }
                }
        }
}

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) }

func TestNonEscapingMap(t *testing.T) {
        t.Skip("does not work on gccgo without better escape analysis")
        n := testing.AllocsPerRun(1000, func() {
                m := make(map[int]int)
                m[0] = 0
        })
        if n != 0 {
                t.Fatalf("want 0 allocs, got %v", n)
        }
}