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// Copyright 2011 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 cgotest
/*
void callback(void *f);
void callGoFoo(void);
*/
import "C"
import (
"./backdoor"
"path"
"runtime"
"strings"
"testing"
"unsafe"
)
// nestedCall calls into C, back into Go, and finally to f.
func nestedCall(f func()) {
// NOTE: Depends on representation of f.
// callback(x) calls goCallback(x)
C.callback(*(*unsafe.Pointer)(unsafe.Pointer(&f)))
}
//export goCallback
func goCallback(p unsafe.Pointer) {
(*(*func())(unsafe.Pointer(&p)))()
}
func testCallback(t *testing.T) {
var x = false
nestedCall(func() { x = true })
if !x {
t.Fatal("nestedCall did not call func")
}
}
func testCallbackGC(t *testing.T) {
nestedCall(runtime.GC)
}
var lockedOSThread = backdoor.LockedOSThread
func testCallbackPanic(t *testing.T) {
// Make sure panic during callback unwinds properly.
if lockedOSThread() {
t.Fatal("locked OS thread on entry to TestCallbackPanic")
}
defer func() {
s := recover()
if s == nil {
t.Fatal("did not panic")
}
if s.(string) != "callback panic" {
t.Fatal("wrong panic:", s)
}
if lockedOSThread() {
t.Fatal("locked OS thread on exit from TestCallbackPanic")
}
}()
nestedCall(func() { panic("callback panic") })
panic("nestedCall returned")
}
func testCallbackPanicLoop(t *testing.T) {
// Make sure we don't blow out m->g0 stack.
for i := 0; i < 100000; i++ {
testCallbackPanic(t)
}
}
func testCallbackPanicLocked(t *testing.T) {
runtime.LockOSThread()
defer runtime.UnlockOSThread()
if !lockedOSThread() {
t.Fatal("runtime.LockOSThread didn't")
}
defer func() {
s := recover()
if s == nil {
t.Fatal("did not panic")
}
if s.(string) != "callback panic" {
t.Fatal("wrong panic:", s)
}
if !lockedOSThread() {
t.Fatal("lost lock on OS thread after panic")
}
}()
nestedCall(func() { panic("callback panic") })
panic("nestedCall returned")
}
// Callback with zero arguments used to make the stack misaligned,
// which broke the garbage collector and other things.
func testZeroArgCallback(t *testing.T) {
defer func() {
s := recover()
if s != nil {
t.Fatal("panic during callback:", s)
}
}()
C.callGoFoo()
}
//export goFoo
func goFoo() {
x := 1
for i := 0; i < 10000; i++ {
// variadic call mallocs + writes to
variadic(x, x, x)
if x != 1 {
panic("bad x")
}
}
}
func variadic(x ...interface{}) {}
func testBlocking(t *testing.T) {
c := make(chan int)
go func() {
for i := 0; i < 10; i++ {
c <- <-c
}
}()
nestedCall(func() {
for i := 0; i < 10; i++ {
c <- i
if j := <-c; j != i {
t.Errorf("out of sync %d != %d", j, i)
}
}
})
}
// Test that the stack can be unwound through a call out and call back
// into Go.
func testCallbackCallers(t *testing.T) {
if runtime.Compiler != "gc" {
// The exact function names are not going to be the same.
t.Skip("skipping for non-gc toolchain")
}
pc := make([]uintptr, 100)
n := 0
name := []string{
"test.goCallback",
"runtime.cgocallbackg",
"runtime.cgocallback_gofunc",
"return",
"runtime.cgocall",
"test._Cfunc_callback",
"test.nestedCall",
"test.testCallbackCallers",
"test.TestCallbackCallers",
"testing.tRunner",
"runtime.goexit",
}
nestedCall(func() {
n = runtime.Callers(2, pc)
})
if n != len(name) {
t.Errorf("expected %d frames, got %d", len(name), n)
}
for i := 0; i < n; i++ {
f := runtime.FuncForPC(pc[i])
if f == nil {
t.Fatalf("expected non-nil Func for pc %p", pc[i])
}
fname := f.Name()
// Remove the prepended pathname from automatically
// generated cgo function names.
if strings.HasPrefix(fname, "_") {
fname = path.Base(f.Name()[1:])
}
if fname != name[i] {
t.Errorf("expected function name %s, got %s", name[i], fname)
}
}
}
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