blob: dd60cba24690a863485bb4ed5c802de4db9f69eb (
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
|
// Copyright 2019 The gVisor 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 pipe
import (
"unsafe"
)
// lockTwoPipes locks both x.mu and y.mu in an order that is guaranteed to be
// consistent for both lockTwoPipes(x, y) and lockTwoPipes(y, x), such that
// concurrent calls cannot deadlock.
//
// Preconditions: x != y.
func lockTwoPipes(x, y *Pipe) {
// Lock the two pipes in order of increasing address.
if uintptr(unsafe.Pointer(x)) < uintptr(unsafe.Pointer(y)) {
x.mu.Lock()
y.mu.Lock()
} else {
y.mu.Lock()
x.mu.Lock()
}
}
|
