From 43a123c1ae6613b3efeed291fa552ecd909d3acf Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Tue, 16 Apr 2024 21:23:18 +0200 Subject: Adding upstream version 1.20.14. Signed-off-by: Daniel Baumann --- src/sync/once_test.go | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 src/sync/once_test.go (limited to 'src/sync/once_test.go') diff --git a/src/sync/once_test.go b/src/sync/once_test.go new file mode 100644 index 0000000..1eec8d1 --- /dev/null +++ b/src/sync/once_test.go @@ -0,0 +1,68 @@ +// 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) + } + }) +} -- cgit v1.2.3