author | Mikael Berthe <mikael@lilotux.net> |
Tue, 23 Aug 2022 22:39:43 +0200 | |
changeset 260 | 445e01aede7e |
parent 256 | 6d9efbef00a9 |
permissions | -rw-r--r-- |
242
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
1 |
// Copyright 2014 The Go Authors. All rights reserved. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
2 |
// Use of this source code is governed by a BSD-style |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
3 |
// license that can be found in the LICENSE file. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
4 |
|
256 | 5 |
//go:build !go1.7 |
242
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
6 |
// +build !go1.7 |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
7 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
8 |
package context |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
9 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
10 |
import ( |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
11 |
"errors" |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
12 |
"fmt" |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
13 |
"sync" |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
14 |
"time" |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
15 |
) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
16 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
17 |
// An emptyCtx is never canceled, has no values, and has no deadline. It is not |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
18 |
// struct{}, since vars of this type must have distinct addresses. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
19 |
type emptyCtx int |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
20 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
21 |
func (*emptyCtx) Deadline() (deadline time.Time, ok bool) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
22 |
return |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
23 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
24 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
25 |
func (*emptyCtx) Done() <-chan struct{} { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
26 |
return nil |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
27 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
28 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
29 |
func (*emptyCtx) Err() error { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
30 |
return nil |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
31 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
32 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
33 |
func (*emptyCtx) Value(key interface{}) interface{} { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
34 |
return nil |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
35 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
36 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
37 |
func (e *emptyCtx) String() string { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
38 |
switch e { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
39 |
case background: |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
40 |
return "context.Background" |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
41 |
case todo: |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
42 |
return "context.TODO" |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
43 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
44 |
return "unknown empty Context" |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
45 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
46 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
47 |
var ( |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
48 |
background = new(emptyCtx) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
49 |
todo = new(emptyCtx) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
50 |
) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
51 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
52 |
// Canceled is the error returned by Context.Err when the context is canceled. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
53 |
var Canceled = errors.New("context canceled") |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
54 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
55 |
// DeadlineExceeded is the error returned by Context.Err when the context's |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
56 |
// deadline passes. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
57 |
var DeadlineExceeded = errors.New("context deadline exceeded") |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
58 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
59 |
// WithCancel returns a copy of parent with a new Done channel. The returned |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
60 |
// context's Done channel is closed when the returned cancel function is called |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
61 |
// or when the parent context's Done channel is closed, whichever happens first. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
62 |
// |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
63 |
// Canceling this context releases resources associated with it, so code should |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
64 |
// call cancel as soon as the operations running in this Context complete. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
65 |
func WithCancel(parent Context) (ctx Context, cancel CancelFunc) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
66 |
c := newCancelCtx(parent) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
67 |
propagateCancel(parent, c) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
68 |
return c, func() { c.cancel(true, Canceled) } |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
69 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
70 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
71 |
// newCancelCtx returns an initialized cancelCtx. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
72 |
func newCancelCtx(parent Context) *cancelCtx { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
73 |
return &cancelCtx{ |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
74 |
Context: parent, |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
75 |
done: make(chan struct{}), |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
76 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
77 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
78 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
79 |
// propagateCancel arranges for child to be canceled when parent is. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
80 |
func propagateCancel(parent Context, child canceler) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
81 |
if parent.Done() == nil { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
82 |
return // parent is never canceled |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
83 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
84 |
if p, ok := parentCancelCtx(parent); ok { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
85 |
p.mu.Lock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
86 |
if p.err != nil { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
87 |
// parent has already been canceled |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
88 |
child.cancel(false, p.err) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
89 |
} else { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
90 |
if p.children == nil { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
91 |
p.children = make(map[canceler]bool) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
92 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
93 |
p.children[child] = true |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
94 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
95 |
p.mu.Unlock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
96 |
} else { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
97 |
go func() { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
98 |
select { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
99 |
case <-parent.Done(): |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
100 |
child.cancel(false, parent.Err()) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
101 |
case <-child.Done(): |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
102 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
103 |
}() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
104 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
105 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
106 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
107 |
// parentCancelCtx follows a chain of parent references until it finds a |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
108 |
// *cancelCtx. This function understands how each of the concrete types in this |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
109 |
// package represents its parent. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
110 |
func parentCancelCtx(parent Context) (*cancelCtx, bool) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
111 |
for { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
112 |
switch c := parent.(type) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
113 |
case *cancelCtx: |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
114 |
return c, true |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
115 |
case *timerCtx: |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
116 |
return c.cancelCtx, true |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
117 |
case *valueCtx: |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
118 |
parent = c.Context |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
119 |
default: |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
120 |
return nil, false |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
121 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
122 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
123 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
124 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
125 |
// removeChild removes a context from its parent. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
126 |
func removeChild(parent Context, child canceler) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
127 |
p, ok := parentCancelCtx(parent) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
128 |
if !ok { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
129 |
return |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
130 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
131 |
p.mu.Lock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
132 |
if p.children != nil { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
133 |
delete(p.children, child) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
134 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
135 |
p.mu.Unlock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
136 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
137 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
138 |
// A canceler is a context type that can be canceled directly. The |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
139 |
// implementations are *cancelCtx and *timerCtx. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
140 |
type canceler interface { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
141 |
cancel(removeFromParent bool, err error) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
142 |
Done() <-chan struct{} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
143 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
144 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
145 |
// A cancelCtx can be canceled. When canceled, it also cancels any children |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
146 |
// that implement canceler. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
147 |
type cancelCtx struct { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
148 |
Context |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
149 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
150 |
done chan struct{} // closed by the first cancel call. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
151 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
152 |
mu sync.Mutex |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
153 |
children map[canceler]bool // set to nil by the first cancel call |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
154 |
err error // set to non-nil by the first cancel call |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
155 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
156 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
157 |
func (c *cancelCtx) Done() <-chan struct{} { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
158 |
return c.done |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
159 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
160 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
161 |
func (c *cancelCtx) Err() error { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
162 |
c.mu.Lock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
163 |
defer c.mu.Unlock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
164 |
return c.err |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
165 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
166 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
167 |
func (c *cancelCtx) String() string { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
168 |
return fmt.Sprintf("%v.WithCancel", c.Context) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
169 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
170 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
171 |
// cancel closes c.done, cancels each of c's children, and, if |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
172 |
// removeFromParent is true, removes c from its parent's children. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
173 |
func (c *cancelCtx) cancel(removeFromParent bool, err error) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
174 |
if err == nil { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
175 |
panic("context: internal error: missing cancel error") |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
176 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
177 |
c.mu.Lock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
178 |
if c.err != nil { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
179 |
c.mu.Unlock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
180 |
return // already canceled |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
181 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
182 |
c.err = err |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
183 |
close(c.done) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
184 |
for child := range c.children { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
185 |
// NOTE: acquiring the child's lock while holding parent's lock. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
186 |
child.cancel(false, err) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
187 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
188 |
c.children = nil |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
189 |
c.mu.Unlock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
190 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
191 |
if removeFromParent { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
192 |
removeChild(c.Context, c) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
193 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
194 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
195 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
196 |
// WithDeadline returns a copy of the parent context with the deadline adjusted |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
197 |
// to be no later than d. If the parent's deadline is already earlier than d, |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
198 |
// WithDeadline(parent, d) is semantically equivalent to parent. The returned |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
199 |
// context's Done channel is closed when the deadline expires, when the returned |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
200 |
// cancel function is called, or when the parent context's Done channel is |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
201 |
// closed, whichever happens first. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
202 |
// |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
203 |
// Canceling this context releases resources associated with it, so code should |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
204 |
// call cancel as soon as the operations running in this Context complete. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
205 |
func WithDeadline(parent Context, deadline time.Time) (Context, CancelFunc) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
206 |
if cur, ok := parent.Deadline(); ok && cur.Before(deadline) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
207 |
// The current deadline is already sooner than the new one. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
208 |
return WithCancel(parent) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
209 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
210 |
c := &timerCtx{ |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
211 |
cancelCtx: newCancelCtx(parent), |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
212 |
deadline: deadline, |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
213 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
214 |
propagateCancel(parent, c) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
215 |
d := deadline.Sub(time.Now()) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
216 |
if d <= 0 { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
217 |
c.cancel(true, DeadlineExceeded) // deadline has already passed |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
218 |
return c, func() { c.cancel(true, Canceled) } |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
219 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
220 |
c.mu.Lock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
221 |
defer c.mu.Unlock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
222 |
if c.err == nil { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
223 |
c.timer = time.AfterFunc(d, func() { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
224 |
c.cancel(true, DeadlineExceeded) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
225 |
}) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
226 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
227 |
return c, func() { c.cancel(true, Canceled) } |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
228 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
229 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
230 |
// A timerCtx carries a timer and a deadline. It embeds a cancelCtx to |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
231 |
// implement Done and Err. It implements cancel by stopping its timer then |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
232 |
// delegating to cancelCtx.cancel. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
233 |
type timerCtx struct { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
234 |
*cancelCtx |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
235 |
timer *time.Timer // Under cancelCtx.mu. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
236 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
237 |
deadline time.Time |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
238 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
239 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
240 |
func (c *timerCtx) Deadline() (deadline time.Time, ok bool) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
241 |
return c.deadline, true |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
242 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
243 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
244 |
func (c *timerCtx) String() string { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
245 |
return fmt.Sprintf("%v.WithDeadline(%s [%s])", c.cancelCtx.Context, c.deadline, c.deadline.Sub(time.Now())) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
246 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
247 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
248 |
func (c *timerCtx) cancel(removeFromParent bool, err error) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
249 |
c.cancelCtx.cancel(false, err) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
250 |
if removeFromParent { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
251 |
// Remove this timerCtx from its parent cancelCtx's children. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
252 |
removeChild(c.cancelCtx.Context, c) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
253 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
254 |
c.mu.Lock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
255 |
if c.timer != nil { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
256 |
c.timer.Stop() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
257 |
c.timer = nil |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
258 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
259 |
c.mu.Unlock() |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
260 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
261 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
262 |
// WithTimeout returns WithDeadline(parent, time.Now().Add(timeout)). |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
263 |
// |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
264 |
// Canceling this context releases resources associated with it, so code should |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
265 |
// call cancel as soon as the operations running in this Context complete: |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
266 |
// |
260 | 267 |
// func slowOperationWithTimeout(ctx context.Context) (Result, error) { |
268 |
// ctx, cancel := context.WithTimeout(ctx, 100*time.Millisecond) |
|
269 |
// defer cancel() // releases resources if slowOperation completes before timeout elapses |
|
270 |
// return slowOperation(ctx) |
|
271 |
// } |
|
242
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
272 |
func WithTimeout(parent Context, timeout time.Duration) (Context, CancelFunc) { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
273 |
return WithDeadline(parent, time.Now().Add(timeout)) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
274 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
275 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
276 |
// WithValue returns a copy of parent in which the value associated with key is |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
277 |
// val. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
278 |
// |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
279 |
// Use context Values only for request-scoped data that transits processes and |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
280 |
// APIs, not for passing optional parameters to functions. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
281 |
func WithValue(parent Context, key interface{}, val interface{}) Context { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
282 |
return &valueCtx{parent, key, val} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
283 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
284 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
285 |
// A valueCtx carries a key-value pair. It implements Value for that key and |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
286 |
// delegates all other calls to the embedded Context. |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
287 |
type valueCtx struct { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
288 |
Context |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
289 |
key, val interface{} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
290 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
291 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
292 |
func (c *valueCtx) String() string { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
293 |
return fmt.Sprintf("%v.WithValue(%#v, %#v)", c.Context, c.key, c.val) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
294 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
295 |
|
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
296 |
func (c *valueCtx) Value(key interface{}) interface{} { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
297 |
if c.key == key { |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
298 |
return c.val |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
299 |
} |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
300 |
return c.Context.Value(key) |
2a9ec03fe5a1
Use vendoring for backward compatibility
Mikael Berthe <mikael@lilotux.net>
parents:
diff
changeset
|
301 |
} |