blob: 79993d34375a5b81a17977b770dafda9992d2f68 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
/*
*
* Copyright 2022 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package grpcsync
import (
"context"
"google.golang.org/grpc/internal/buffer"
)
// CallbackSerializer provides a mechanism to schedule callbacks in a
// synchronized manner. It provides a FIFO guarantee on the order of execution
// of scheduled callbacks. New callbacks can be scheduled by invoking the
// Schedule() method.
//
// This type is safe for concurrent access.
type CallbackSerializer struct {
callbacks *buffer.Unbounded
}
// NewCallbackSerializer returns a new CallbackSerializer instance. The provided
// context will be passed to the scheduled callbacks. Users should cancel the
// provided context to shutdown the CallbackSerializer. It is guaranteed that no
// callbacks will be executed once this context is canceled.
func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
t := &CallbackSerializer{callbacks: buffer.NewUnbounded()}
go t.run(ctx)
return t
}
// Schedule adds a callback to be scheduled after existing callbacks are run.
//
// Callbacks are expected to honor the context when performing any blocking
// operations, and should return early when the context is canceled.
func (t *CallbackSerializer) Schedule(f func(ctx context.Context)) {
t.callbacks.Put(f)
}
func (t *CallbackSerializer) run(ctx context.Context) {
for ctx.Err() == nil {
select {
case <-ctx.Done():
return
case callback := <-t.callbacks.Get():
t.callbacks.Load()
callback.(func(ctx context.Context))(ctx)
}
}
}
|
