You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
120 lines
3.4 KiB
120 lines
3.4 KiB
// Copyright (c) 2020-{{.ToYear}} Uber Technologies, Inc. |
|
// |
|
// Permission is hereby granted, free of charge, to any person obtaining a copy |
|
// of this software and associated documentation files (the "Software"), to deal |
|
// in the Software without restriction, including without limitation the rights |
|
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
|
// copies of the Software, and to permit persons to whom the Software is |
|
// furnished to do so, subject to the following conditions: |
|
// |
|
// The above copyright notice and this permission notice shall be included in |
|
// all copies or substantial portions of the Software. |
|
// |
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
|
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
|
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
|
// THE SOFTWARE. |
|
|
|
package atomic |
|
|
|
{{ with .Imports }} |
|
import ( |
|
{{ range . -}} |
|
{{ printf "%q" . }} |
|
{{ end }} |
|
) |
|
{{ end }} |
|
|
|
// {{ .Name }} is an atomic type-safe wrapper for {{ .Type }} values. |
|
type {{ .Name }} struct{ |
|
_ nocmp // disallow non-atomic comparison |
|
|
|
v {{ .Wrapped }} |
|
} |
|
|
|
var _zero{{ .Name }} {{ .Type }} |
|
|
|
|
|
// New{{ .Name }} creates a new {{ .Name }}. |
|
func New{{ .Name }}(val {{ .Type }}) *{{ .Name }} { |
|
x := &{{ .Name }}{} |
|
if val != _zero{{ .Name }} { |
|
x.Store(val) |
|
} |
|
return x |
|
} |
|
|
|
// Load atomically loads the wrapped {{ .Type }}. |
|
func (x *{{ .Name }}) Load() {{ .Type }} { |
|
{{ if .Unpack -}} |
|
return {{ .Unpack }}(x.v.Load()) |
|
{{- else -}} |
|
if v := x.v.Load(); v != nil { |
|
return v.({{ .Type }}) |
|
} |
|
return _zero{{ .Name }} |
|
{{- end }} |
|
} |
|
|
|
// Store atomically stores the passed {{ .Type }}. |
|
func (x *{{ .Name }}) Store(val {{ .Type }}) { |
|
x.v.Store({{ .Pack }}(val)) |
|
} |
|
|
|
{{ if .CAS -}} |
|
// CAS is an atomic compare-and-swap for {{ .Type }} values. |
|
// |
|
// Deprecated: Use CompareAndSwap. |
|
func (x *{{ .Name }}) CAS(old, new {{ .Type }}) (swapped bool) { |
|
return x.CompareAndSwap(old, new) |
|
} |
|
{{- end }} |
|
|
|
{{ if .CompareAndSwap -}} |
|
// CompareAndSwap is an atomic compare-and-swap for {{ .Type }} values. |
|
func (x *{{ .Name }}) CompareAndSwap(old, new {{ .Type }}) (swapped bool) { |
|
{{ if eq .Wrapped "Value" -}} |
|
if x.v.CompareAndSwap({{ .Pack }}(old), {{ .Pack }}(new)) { |
|
return true |
|
} |
|
|
|
if old == _zero{{ .Name }} { |
|
// If the old value is the empty value, then it's possible the |
|
// underlying Value hasn't been set and is nil, so retry with nil. |
|
return x.v.CompareAndSwap(nil, {{ .Pack }}(new)) |
|
} |
|
|
|
return false |
|
{{- else -}} |
|
return x.v.CompareAndSwap({{ .Pack }}(old), {{ .Pack }}(new)) |
|
{{- end }} |
|
} |
|
{{- end }} |
|
|
|
{{ if .Swap -}} |
|
// Swap atomically stores the given {{ .Type }} and returns the old |
|
// value. |
|
func (x *{{ .Name }}) Swap(val {{ .Type }}) (old {{ .Type }}) { |
|
return {{ .Unpack }}(x.v.Swap({{ .Pack }}(val))) |
|
} |
|
{{- end }} |
|
|
|
{{ if .JSON -}} |
|
// MarshalJSON encodes the wrapped {{ .Type }} into JSON. |
|
func (x *{{ .Name }}) MarshalJSON() (by, er) { |
|
return json.Marshal(x.Load()) |
|
} |
|
|
|
// UnmarshalJSON decodes a {{ .Type }} from JSON. |
|
func (x *{{ .Name }}) UnmarshalJSON(b by) er { |
|
var v {{ .Type }} |
|
if err := json.Unmarshal(b, &v); err != nil { |
|
return err |
|
} |
|
x.Store(v) |
|
return nil |
|
} |
|
{{- end }}
|
|
|