gcc/libgo/go/sync/once_test.go
Ian Lance Taylor f8d9fa9e80 libgo, compiler: Upgrade libgo to Go 1.4, except for runtime.
This upgrades all of libgo other than the runtime package to
the Go 1.4 release.  In Go 1.4 much of the runtime was
rewritten into Go.  Merging that code will take more time and
will not change the API, so I'm putting it off for now.

There are a few runtime changes anyhow, to accomodate other
packages that rely on minor modifications to the runtime
support.

The compiler changes slightly to add a one-bit flag to each
type descriptor kind that is stored directly in an interface,
which for gccgo is currently only pointer types.  Another
one-bit flag (gcprog) is reserved because it is used by the gc
compiler, but gccgo does not currently use it.

There is another error check in the compiler since I ran
across it during testing.

gotools/:
	* Makefile.am (go_cmd_go_files): Sort entries.  Add generate.go.
	* Makefile.in: Rebuild.

From-SVN: r219627
2015-01-15 00:27:56 +00:00

69 lines
1.1 KiB
Go

// Copyright 2009 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 sync_test
import (
. "sync"
"testing"
)
type one int
func (o *one) Increment() {
*o++
}
func run(t *testing.T, once *Once, o *one, c chan bool) {
once.Do(func() { o.Increment() })
if v := *o; v != 1 {
t.Errorf("once failed inside run: %d is not 1", v)
}
c <- true
}
func TestOnce(t *testing.T) {
o := new(one)
once := new(Once)
c := make(chan bool)
const N = 10
for i := 0; i < N; i++ {
go run(t, once, o, c)
}
for i := 0; i < N; i++ {
<-c
}
if *o != 1 {
t.Errorf("once failed outside run: %d is not 1", *o)
}
}
func TestOncePanic(t *testing.T) {
var once Once
func() {
defer func() {
if r := recover(); r == nil {
t.Fatalf("Once.Do did not panic")
}
}()
once.Do(func() {
panic("failed")
})
}()
once.Do(func() {
t.Fatalf("Once.Do called twice")
})
}
func BenchmarkOnce(b *testing.B) {
var once Once
f := func() {}
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
once.Do(f)
}
})
}