blob: dac751669d2446f078559ade99f8f3296f9bb1a8 (
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
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
|
// Copyright 2016 The Bazel Authors. 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 com.google.devtools.build.lib.shell;
import com.google.devtools.build.lib.shell.SubprocessBuilder.StreamAction;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.ProcessBuilder.Redirect;
/**
* A subprocess factory that uses {@link java.lang.ProcessBuilder}.
*/
public class JavaSubprocessFactory implements Subprocess.Factory {
/**
* A subprocess backed by a {@link java.lang.Process}.
*/
private static class JavaSubprocess implements Subprocess {
private final Process process;
private JavaSubprocess(Process process) {
this.process = process;
}
@Override
public boolean destroy() {
process.destroy();
return true;
}
@Override
public int exitValue() {
return process.exitValue();
}
@Override
public boolean finished() {
try {
// this seems to be the only non-blocking call for checking liveness
process.exitValue();
return true;
} catch (IllegalThreadStateException e) {
return false;
}
}
@Override
public boolean timedout() {
// Not supported.
return false;
}
@Override
public void waitFor() throws InterruptedException {
process.waitFor();
}
@Override
public OutputStream getOutputStream() {
return process.getOutputStream();
}
@Override
public InputStream getErrorStream() {
return process.getErrorStream();
}
@Override
public InputStream getInputStream() {
return process.getInputStream();
}
@Override
public void close() {
// java.lang.Process doesn't give us a way to clean things up other than #destroy()
}
}
public static final JavaSubprocessFactory INSTANCE = new JavaSubprocessFactory();
private JavaSubprocessFactory() {
// We are a singleton
}
@Override
public Subprocess create(SubprocessBuilder params) throws IOException {
if (params.getTimeoutMillis() >= 0) {
throw new UnsupportedOperationException("Timeouts are not supported");
}
ProcessBuilder builder = new ProcessBuilder();
builder.command(params.getArgv());
if (params.getEnv() != null) {
builder.environment().clear();
builder.environment().putAll(params.getEnv());
}
builder.redirectOutput(getRedirect(params.getStdout(), params.getStdoutFile()));
builder.redirectError(getRedirect(params.getStderr(), params.getStderrFile()));
builder.directory(params.getWorkingDirectory());
return new JavaSubprocess(builder.start());
}
/**
* Returns a {@link ProcessBuilder.Redirect} appropriate for the parameters. If a file redirected
* to exists, deletes the file before redirecting to it.
*/
private Redirect getRedirect(StreamAction action, File file) {
switch (action) {
case DISCARD:
return Redirect.to(new File("/dev/null"));
case REDIRECT:
// We need to use Redirect.appendTo() here, because on older Linux kernels writes are
// otherwise not atomic and might result in lost log messages:
// https://lkml.org/lkml/2014/3/3/308
if (file.exists()) {
file.delete();
}
return Redirect.appendTo(file);
case STREAM:
return Redirect.PIPE;
default:
throw new IllegalStateException();
}
}
}
|
