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
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
// Copyright 2017 Google Inc. All rights reserved.
//
// 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 build
import (
"errors"
"fmt"
"math"
"os"
"path/filepath"
"syscall"
"time"
"android/soong/ui/logger"
)
// This file provides cross-process synchronization methods
// i.e. making sure only one Soong process is running for a given output directory
func BecomeSingletonOrFail(ctx Context, config Config) (lock *fileLock) {
lockingInfo, err := newLock(config.OutDir())
if err != nil {
ctx.Logger.Fatal(err)
}
lockfilePollDuration := time.Second
lockfileTimeout := time.Second * 10
if envTimeout := os.Getenv("SOONG_LOCK_TIMEOUT"); envTimeout != "" {
lockfileTimeout, err = time.ParseDuration(envTimeout)
if err != nil {
ctx.Logger.Fatalf("failure parsing SOONG_LOCK_TIMEOUT %q: %s", envTimeout, err)
}
}
err = lockSynchronous(*lockingInfo, newSleepWaiter(lockfilePollDuration, lockfileTimeout), ctx.Logger)
if err != nil {
ctx.Logger.Fatal(err)
}
return lockingInfo
}
type lockable interface {
tryLock() error
Unlock() error
description() string
}
var _ lockable = (*fileLock)(nil)
type fileLock struct {
File *os.File
}
func (l fileLock) description() (path string) {
return l.File.Name()
}
func (l fileLock) tryLock() (err error) {
return syscall.Flock(int(l.File.Fd()), syscall.LOCK_EX|syscall.LOCK_NB)
}
func (l fileLock) Unlock() (err error) {
return l.File.Close()
}
func lockSynchronous(lock lockable, waiter waiter, logger logger.Logger) (err error) {
waited := false
for {
err = lock.tryLock()
if err == nil {
if waited {
// If we had to wait at all, then when the wait is done, we inform the user
logger.Printf("Acquired lock on %v; previous Soong process must have completed. Continuing...\n", lock.description())
}
return nil
}
done, description := waiter.checkDeadline()
if !waited {
logger.Printf("Waiting up to %s to lock %v to ensure no other Soong process is running in the same output directory\n", description, lock.description())
}
waited = true
if done {
return fmt.Errorf("Tried to lock %s, but timed out %s . Make sure no other Soong process is using it",
lock.description(), waiter.summarize())
} else {
waiter.wait()
}
}
}
func newLock(basedir string) (lock *fileLock, err error) {
lockPath := filepath.Join(basedir, ".lock")
os.MkdirAll(basedir, 0777)
lockfileDescriptor, err := os.OpenFile(lockPath, os.O_RDWR|os.O_CREATE, 0666)
if err != nil {
return nil, errors.New("failed to open " + lockPath)
}
lockingInfo := &fileLock{File: lockfileDescriptor}
return lockingInfo, nil
}
type waiter interface {
wait()
checkDeadline() (done bool, remainder string)
summarize() (summary string)
}
type sleepWaiter struct {
sleepInterval time.Duration
deadline time.Time
totalWait time.Duration
}
var _ waiter = (*sleepWaiter)(nil)
func newSleepWaiter(interval time.Duration, duration time.Duration) (waiter *sleepWaiter) {
return &sleepWaiter{interval, time.Now().Add(duration), duration}
}
func (s sleepWaiter) wait() {
time.Sleep(s.sleepInterval)
}
func (s *sleepWaiter) checkDeadline() (done bool, remainder string) {
remainingSleep := s.deadline.Sub(time.Now())
numSecondsRounded := math.Floor(remainingSleep.Seconds()*10+0.5) / 10
if remainingSleep > 0 {
return false, fmt.Sprintf("%vs", numSecondsRounded)
} else {
return true, ""
}
}
func (s sleepWaiter) summarize() (summary string) {
return fmt.Sprintf("polling every %v until %v", s.sleepInterval, s.totalWait)
}
|
