src/runtime/runtime_test.go - go - Git at Google

 // 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 (
 	"io"
 	"io/ioutil"
 	"os"
 	"os/exec"
 	. "runtime"
 	"runtime/debug"
 	"strconv"
 	"strings"
 	"testing"
 	"unsafe"
 )

 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")
 			}
 		}
 	}
 }

 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)
 	return
 }

 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)
 	}
 }

 // The profiling signal handler needs to know whether it is executing runtime.gogo.
 // The constant RuntimeGogoBytes in arch_*.h gives the size of the function;
 // we don't have a way to obtain it from the linker (perhaps someday).
 // Test that the constant matches the size determined by 'go tool nm -S'.
 // The value reported will include the padding between runtime.gogo and the
 // next function in memory. That's fine.
 func TestRuntimeGogoBytes(t *testing.T) {
 	switch GOOS {
 	case "android", "nacl":
 		t.Skipf("skipping on %s", GOOS)
 	}

 	dir, err := ioutil.TempDir("", "go-build")
 	if err != nil {
 		t.Fatalf("failed to create temp directory: %v", err)
 	}
 	defer os.RemoveAll(dir)

 	out, err := exec.Command("go", "build", "-o", dir+"/hello", "../../test/helloworld.go").CombinedOutput()
 	if err != nil {
 		t.Fatalf("building hello world: %v\n%s", err, out)
 	}

 	out, err = exec.Command("go", "tool", "nm", "-size", dir+"/hello").CombinedOutput()
 	if err != nil {
 		t.Fatalf("go tool nm: %v\n%s", err, out)
 	}

 	for _, line := range strings.Split(string(out), "\n") {
 		f := strings.Fields(line)
 		if len(f) == 4 && f[3] == "runtime.gogo" {
 			size, _ := strconv.Atoi(f[1])
 			if GogoBytes() != int32(size) {
 				t.Fatalf("RuntimeGogoBytes = %d, should be %d", GogoBytes(), size)
 			}
 			return
 		}
 	}

 	t.Fatalf("go tool nm did not report size for runtime.gogo")
 }

 // 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
 // adderesses 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) {
 	// This currently results in a fault in the signal trampoline on
 	// dragonfly/386 - see issue 7421.
 	if GOOS == "dragonfly" && GOARCH == "386" {
 		t.Skip("skipping test on dragonfly/386")
 	}

 	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")
 	}
 }

 func testSetPanicOnFault(t *testing.T, addr uintptr, nfault *int) {
 	if GOOS == "nacl" {
 		t.Skip("nacl doesn't seem to fault on high addresses")
 	}

 	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 eqstring, it's
 	// just a convenient way of documenting (via eqstring_generic)
 	// what eqstring 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(`eqstring("%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(Uintreg(0)) {
 		t.Errorf("sizeof(%#v)==%d, want %d", T2{}, unsafe.Sizeof(T2{}), 8 + unsafe.Sizeof(Uintreg(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{}))
 	}
 }
	// 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 (
	"io"
	"io/ioutil"
	"os"
	"os/exec"
	. "runtime"
	"runtime/debug"
	"strconv"
	"strings"
	"testing"
	"unsafe"
	)

	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")
	}
	}
	}
	}

	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)
	return
	}

	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)
	}
	}

	// The profiling signal handler needs to know whether it is executing runtime.gogo.
	// The constant RuntimeGogoBytes in arch_*.h gives the size of the function;
	// we don't have a way to obtain it from the linker (perhaps someday).
	// Test that the constant matches the size determined by 'go tool nm -S'.
	// The value reported will include the padding between runtime.gogo and the
	// next function in memory. That's fine.
	func TestRuntimeGogoBytes(t *testing.T) {
	switch GOOS {
	case "android", "nacl":
	t.Skipf("skipping on %s", GOOS)
	}

	dir, err := ioutil.TempDir("", "go-build")
	if err != nil {
	t.Fatalf("failed to create temp directory: %v", err)
	}
	defer os.RemoveAll(dir)

	out, err := exec.Command("go", "build", "-o", dir+"/hello", "../../test/helloworld.go").CombinedOutput()
	if err != nil {
	t.Fatalf("building hello world: %v\n%s", err, out)
	}

	out, err = exec.Command("go", "tool", "nm", "-size", dir+"/hello").CombinedOutput()
	if err != nil {
	t.Fatalf("go tool nm: %v\n%s", err, out)
	}

	for _, line := range strings.Split(string(out), "\n") {
	f := strings.Fields(line)
	if len(f) == 4 && f[3] == "runtime.gogo" {
	size, _ := strconv.Atoi(f[1])
	if GogoBytes() != int32(size) {
	t.Fatalf("RuntimeGogoBytes = %d, should be %d", GogoBytes(), size)
	}
	return
	}
	}

	t.Fatalf("go tool nm did not report size for runtime.gogo")
	}

	// 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
	// adderesses 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) {
	// This currently results in a fault in the signal trampoline on
	// dragonfly/386 - see issue 7421.
	if GOOS == "dragonfly" && GOARCH == "386" {
	t.Skip("skipping test on dragonfly/386")
	}

	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")
	}
	}

	func testSetPanicOnFault(t testing.T, addr uintptr, nfault int) {
	if GOOS == "nacl" {
	t.Skip("nacl doesn't seem to fault on high addresses")
	}

	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 eqstring, it's
	// just a convenient way of documenting (via eqstring_generic)
	// what eqstring 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(`eqstring("%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(Uintreg(0)) {
	t.Errorf("sizeof(%#v)==%d, want %d", T2{}, unsafe.Sizeof(T2{}), 8 + unsafe.Sizeof(Uintreg(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{}))
	}
	}