Current File : //usr/local/go119/src/runtime/runtime_test.go
// Copyright 2012 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 (
"flag"
"fmt"
"io"
. "runtime"
"runtime/debug"
"sort"
"strings"
"sync"
"testing"
"time"
"unsafe"
)
// flagQuick is set by the -quick option to skip some relatively slow tests.
// This is used by the cmd/dist test runtime:cpu124.
// The cmd/dist test passes both -test.short and -quick;
// there are tests that only check testing.Short, and those tests will
// not be skipped if only -quick is used.
var flagQuick = flag.Bool("quick", false, "skip slow tests, for cmd/dist test runtime:cpu124")
func init() {
// We're testing the runtime, so make tracebacks show things
// in the runtime. This only raises the level, so it won't
// override GOTRACEBACK=crash from the user.
SetTracebackEnv("system")
}
var errf error
func errfn() error {
return errf
}
func errfn1() error {
return io.EOF
}
func BenchmarkIfaceCmp100(b *testing.B) {
for i := 0; i < b.N; i++ {
for j := 0; j < 100; j++ {
if errfn() == io.EOF {
b.Fatal("bad comparison")
}
}
}
}
func BenchmarkIfaceCmpNil100(b *testing.B) {
for i := 0; i < b.N; i++ {
for j := 0; j < 100; j++ {
if errfn1() == nil {
b.Fatal("bad comparison")
}
}
}
}
var efaceCmp1 any
var efaceCmp2 any
func BenchmarkEfaceCmpDiff(b *testing.B) {
x := 5
efaceCmp1 = &x
y := 6
efaceCmp2 = &y
for i := 0; i < b.N; i++ {
for j := 0; j < 100; j++ {
if efaceCmp1 == efaceCmp2 {
b.Fatal("bad comparison")
}
}
}
}
func BenchmarkEfaceCmpDiffIndirect(b *testing.B) {
efaceCmp1 = [2]int{1, 2}
efaceCmp2 = [2]int{1, 2}
for i := 0; i < b.N; i++ {
for j := 0; j < 100; j++ {
if efaceCmp1 != efaceCmp2 {
b.Fatal("bad comparison")
}
}
}
}
func BenchmarkDefer(b *testing.B) {
for i := 0; i < b.N; i++ {
defer1()
}
}
func defer1() {
defer func(x, y, z int) {
if recover() != nil || x != 1 || y != 2 || z != 3 {
panic("bad recover")
}
}(1, 2, 3)
}
func BenchmarkDefer10(b *testing.B) {
for i := 0; i < b.N/10; i++ {
defer2()
}
}
func defer2() {
for i := 0; i < 10; i++ {
defer func(x, y, z int) {
if recover() != nil || x != 1 || y != 2 || z != 3 {
panic("bad recover")
}
}(1, 2, 3)
}
}
func BenchmarkDeferMany(b *testing.B) {
for i := 0; i < b.N; i++ {
defer func(x, y, z int) {
if recover() != nil || x != 1 || y != 2 || z != 3 {
panic("bad recover")
}
}(1, 2, 3)
}
}
func BenchmarkPanicRecover(b *testing.B) {
for i := 0; i < b.N; i++ {
defer3()
}
}
func defer3() {
defer func(x, y, z int) {
if recover() == nil {
panic("failed recover")
}
}(1, 2, 3)
panic("hi")
}
// golang.org/issue/7063
func TestStopCPUProfilingWithProfilerOff(t *testing.T) {
SetCPUProfileRate(0)
}
// Addresses to test for faulting behavior.
// This is less a test of SetPanicOnFault and more a check that
// the operating system and the runtime can process these faults
// correctly. That is, we're indirectly testing that without SetPanicOnFault
// these would manage to turn into ordinary crashes.
// Note that these are truncated on 32-bit systems, so the bottom 32 bits
// of the larger addresses must themselves be invalid addresses.
// We might get unlucky and the OS might have mapped one of these
// addresses, but probably not: they're all in the first page, very high
// addresses that normally an OS would reserve for itself, or malformed
// addresses. Even so, we might have to remove one or two on different
// systems. We will see.
var faultAddrs = []uint64{
// low addresses
0,
1,
0xfff,
// high (kernel) addresses
// or else malformed.
0xffffffffffffffff,
0xfffffffffffff001,
0xffffffffffff0001,
0xfffffffffff00001,
0xffffffffff000001,
0xfffffffff0000001,
0xffffffff00000001,
0xfffffff000000001,
0xffffff0000000001,
0xfffff00000000001,
0xffff000000000001,
0xfff0000000000001,
0xff00000000000001,
0xf000000000000001,
0x8000000000000001,
}
func TestSetPanicOnFault(t *testing.T) {
old := debug.SetPanicOnFault(true)
defer debug.SetPanicOnFault(old)
nfault := 0
for _, addr := range faultAddrs {
testSetPanicOnFault(t, uintptr(addr), &nfault)
}
if nfault == 0 {
t.Fatalf("none of the addresses faulted")
}
}
// testSetPanicOnFault tests one potentially faulting address.
// It deliberately constructs and uses an invalid pointer,
// so mark it as nocheckptr.
//
//go:nocheckptr
func testSetPanicOnFault(t *testing.T, addr uintptr, nfault *int) {
if GOOS == "js" {
t.Skip("js does not support catching faults")
}
defer func() {
if err := recover(); err != nil {
*nfault++
}
}()
// The read should fault, except that sometimes we hit
// addresses that have had C or kernel pages mapped there
// readable by user code. So just log the content.
// If no addresses fault, we'll fail the test.
v := *(*byte)(unsafe.Pointer(addr))
t.Logf("addr %#x: %#x\n", addr, v)
}
func eqstring_generic(s1, s2 string) bool {
if len(s1) != len(s2) {
return false
}
// optimization in assembly versions:
// if s1.str == s2.str { return true }
for i := 0; i < len(s1); i++ {
if s1[i] != s2[i] {
return false
}
}
return true
}
func TestEqString(t *testing.T) {
// This isn't really an exhaustive test of == on strings, it's
// just a convenient way of documenting (via eqstring_generic)
// what == does.
s := []string{
"",
"a",
"c",
"aaa",
"ccc",
"cccc"[:3], // same contents, different string
"1234567890",
}
for _, s1 := range s {
for _, s2 := range s {
x := s1 == s2
y := eqstring_generic(s1, s2)
if x != y {
t.Errorf(`("%s" == "%s") = %t, want %t`, s1, s2, x, y)
}
}
}
}
func TestTrailingZero(t *testing.T) {
// make sure we add padding for structs with trailing zero-sized fields
type T1 struct {
n int32
z [0]byte
}
if unsafe.Sizeof(T1{}) != 8 {
t.Errorf("sizeof(%#v)==%d, want 8", T1{}, unsafe.Sizeof(T1{}))
}
type T2 struct {
n int64
z struct{}
}
if unsafe.Sizeof(T2{}) != 8+unsafe.Sizeof(uintptr(0)) {
t.Errorf("sizeof(%#v)==%d, want %d", T2{}, unsafe.Sizeof(T2{}), 8+unsafe.Sizeof(uintptr(0)))
}
type T3 struct {
n byte
z [4]struct{}
}
if unsafe.Sizeof(T3{}) != 2 {
t.Errorf("sizeof(%#v)==%d, want 2", T3{}, unsafe.Sizeof(T3{}))
}
// make sure padding can double for both zerosize and alignment
type T4 struct {
a int32
b int16
c int8
z struct{}
}
if unsafe.Sizeof(T4{}) != 8 {
t.Errorf("sizeof(%#v)==%d, want 8", T4{}, unsafe.Sizeof(T4{}))
}
// make sure we don't pad a zero-sized thing
type T5 struct {
}
if unsafe.Sizeof(T5{}) != 0 {
t.Errorf("sizeof(%#v)==%d, want 0", T5{}, unsafe.Sizeof(T5{}))
}
}
func TestAppendGrowth(t *testing.T) {
var x []int64
check := func(want int) {
if cap(x) != want {
t.Errorf("len=%d, cap=%d, want cap=%d", len(x), cap(x), want)
}
}
check(0)
want := 1
for i := 1; i <= 100; i++ {
x = append(x, 1)
check(want)
if i&(i-1) == 0 {
want = 2 * i
}
}
}
var One = []int64{1}
func TestAppendSliceGrowth(t *testing.T) {
var x []int64
check := func(want int) {
if cap(x) != want {
t.Errorf("len=%d, cap=%d, want cap=%d", len(x), cap(x), want)
}
}
check(0)
want := 1
for i := 1; i <= 100; i++ {
x = append(x, One...)
check(want)
if i&(i-1) == 0 {
want = 2 * i
}
}
}
func TestGoroutineProfileTrivial(t *testing.T) {
// Calling GoroutineProfile twice in a row should find the same number of goroutines,
// but it's possible there are goroutines just about to exit, so we might end up
// with fewer in the second call. Try a few times; it should converge once those
// zombies are gone.
for i := 0; ; i++ {
n1, ok := GoroutineProfile(nil) // should fail, there's at least 1 goroutine
if n1 < 1 || ok {
t.Fatalf("GoroutineProfile(nil) = %d, %v, want >0, false", n1, ok)
}
n2, ok := GoroutineProfile(make([]StackRecord, n1))
if n2 == n1 && ok {
break
}
t.Logf("GoroutineProfile(%d) = %d, %v, want %d, true", n1, n2, ok, n1)
if i >= 10 {
t.Fatalf("GoroutineProfile not converging")
}
}
}
func BenchmarkGoroutineProfile(b *testing.B) {
run := func(fn func() bool) func(b *testing.B) {
runOne := func(b *testing.B) {
latencies := make([]time.Duration, 0, b.N)
b.ResetTimer()
for i := 0; i < b.N; i++ {
start := time.Now()
ok := fn()
if !ok {
b.Fatal("goroutine profile failed")
}
latencies = append(latencies, time.Now().Sub(start))
}
b.StopTimer()
// Sort latencies then report percentiles.
sort.Slice(latencies, func(i, j int) bool {
return latencies[i] < latencies[j]
})
b.ReportMetric(float64(latencies[len(latencies)*50/100]), "p50-ns")
b.ReportMetric(float64(latencies[len(latencies)*90/100]), "p90-ns")
b.ReportMetric(float64(latencies[len(latencies)*99/100]), "p99-ns")
}
return func(b *testing.B) {
b.Run("idle", runOne)
b.Run("loaded", func(b *testing.B) {
stop := applyGCLoad(b)
runOne(b)
// Make sure to stop the timer before we wait! The load created above
// is very heavy-weight and not easy to stop, so we could end up
// confusing the benchmarking framework for small b.N.
b.StopTimer()
stop()
})
}
}
// Measure the cost of counting goroutines
b.Run("small-nil", run(func() bool {
GoroutineProfile(nil)
return true
}))
// Measure the cost with a small set of goroutines
n := NumGoroutine()
p := make([]StackRecord, 2*n+2*GOMAXPROCS(0))
b.Run("small", run(func() bool {
_, ok := GoroutineProfile(p)
return ok
}))
// Measure the cost with a large set of goroutines
ch := make(chan int)
var ready, done sync.WaitGroup
for i := 0; i < 5000; i++ {
ready.Add(1)
done.Add(1)
go func() { ready.Done(); <-ch; done.Done() }()
}
ready.Wait()
// Count goroutines with a large allgs list
b.Run("large-nil", run(func() bool {
GoroutineProfile(nil)
return true
}))
n = NumGoroutine()
p = make([]StackRecord, 2*n+2*GOMAXPROCS(0))
b.Run("large", run(func() bool {
_, ok := GoroutineProfile(p)
return ok
}))
close(ch)
done.Wait()
// Count goroutines with a large (but unused) allgs list
b.Run("sparse-nil", run(func() bool {
GoroutineProfile(nil)
return true
}))
// Measure the cost of a large (but unused) allgs list
n = NumGoroutine()
p = make([]StackRecord, 2*n+2*GOMAXPROCS(0))
b.Run("sparse", run(func() bool {
_, ok := GoroutineProfile(p)
return ok
}))
}
func TestVersion(t *testing.T) {
// Test that version does not contain \r or \n.
vers := Version()
if strings.Contains(vers, "\r") || strings.Contains(vers, "\n") {
t.Fatalf("cr/nl in version: %q", vers)
}
}
func TestTimediv(t *testing.T) {
for _, tc := range []struct {
num int64
div int32
ret int32
rem int32
}{
{
num: 8,
div: 2,
ret: 4,
rem: 0,
},
{
num: 9,
div: 2,
ret: 4,
rem: 1,
},
{
// Used by runtime.check.
num: 12345*1000000000 + 54321,
div: 1000000000,
ret: 12345,
rem: 54321,
},
{
num: 1<<32 - 1,
div: 2,
ret: 1<<31 - 1, // no overflow.
rem: 1,
},
{
num: 1 << 32,
div: 2,
ret: 1<<31 - 1, // overflow.
rem: 0,
},
{
num: 1 << 40,
div: 2,
ret: 1<<31 - 1, // overflow.
rem: 0,
},
{
num: 1<<40 + 1,
div: 1 << 10,
ret: 1 << 30,
rem: 1,
},
} {
name := fmt.Sprintf("%d div %d", tc.num, tc.div)
t.Run(name, func(t *testing.T) {
// Double check that the inputs make sense using
// standard 64-bit division.
ret64 := tc.num / int64(tc.div)
rem64 := tc.num % int64(tc.div)
if ret64 != int64(int32(ret64)) {
// Simulate timediv overflow value.
ret64 = 1<<31 - 1
rem64 = 0
}
if ret64 != int64(tc.ret) {
t.Errorf("%d / %d got ret %d rem %d want ret %d rem %d", tc.num, tc.div, ret64, rem64, tc.ret, tc.rem)
}
var rem int32
ret := Timediv(tc.num, tc.div, &rem)
if ret != tc.ret || rem != tc.rem {
t.Errorf("timediv %d / %d got ret %d rem %d want ret %d rem %d", tc.num, tc.div, ret, rem, tc.ret, tc.rem)
}
})
}
}
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