mirror of
https://github.com/golang/go
synced 2024-11-07 03:36:12 -07:00
5355753009
We don't usually reformat the test directory, but all of the files in test/typeparam are syntactically valid. I suspect the misformattings here are because developers aren't re-installing gofmt with -tags=typeparams, not intentionally exercising non-standard formatting. Change-Id: I3767d480434c19225568f3c7d656dc8589197183 Reviewed-on: https://go-review.googlesource.com/c/go/+/338093 Trust: Matthew Dempsky <mdempsky@google.com> Trust: Robert Griesemer <gri@golang.org> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org>
51 lines
930 B
Go
51 lines
930 B
Go
// run -gcflags=-G=3
|
|
|
|
// Copyright 2021 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 main
|
|
|
|
import "sync"
|
|
|
|
// A Lockable is a value that may be safely simultaneously accessed
|
|
// from multiple goroutines via the Get and Set methods.
|
|
type Lockable[T any] struct {
|
|
x T
|
|
mu sync.Mutex
|
|
}
|
|
|
|
// Get returns the value stored in a Lockable.
|
|
func (l *Lockable[T]) get() T {
|
|
l.mu.Lock()
|
|
defer l.mu.Unlock()
|
|
return l.x
|
|
}
|
|
|
|
// set sets the value in a Lockable.
|
|
func (l *Lockable[T]) set(v T) {
|
|
l.mu.Lock()
|
|
defer l.mu.Unlock()
|
|
l.x = v
|
|
}
|
|
|
|
func main() {
|
|
sl := Lockable[string]{x: "a"}
|
|
if got := sl.get(); got != "a" {
|
|
panic(got)
|
|
}
|
|
sl.set("b")
|
|
if got := sl.get(); got != "b" {
|
|
panic(got)
|
|
}
|
|
|
|
il := Lockable[int]{x: 1}
|
|
if got := il.get(); got != 1 {
|
|
panic(got)
|
|
}
|
|
il.set(2)
|
|
if got := il.get(); got != 2 {
|
|
panic(got)
|
|
}
|
|
}
|