1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.rng.examples.stress;
18
19 import java.io.File;
20 import java.io.IOException;
21 import java.util.ArrayList;
22 import java.util.List;
23
24 /**
25 * Utility methods for a {@link Process}.
26 */
27 final class ProcessUtils {
28 /** The timeout to wait for the process exit value in milliseconds. */
29 private static final long DEFAULT_TIMEOUT_MILLIS = 1000L;
30
31 /** No public construction. */
32 private ProcessUtils() {}
33
34 /**
35 * Check the executable exists and has execute permissions.
36 *
37 * @param executable The executable.
38 * @throws ApplicationException If the executable is invalid.
39 */
40 static void checkExecutable(File executable) {
41 if (!executable.exists() ||
42 !executable.canExecute()) {
43 throw new ApplicationException("Program is not executable: " + executable);
44 }
45 }
46
47 /**
48 * Check the output directory exists and has write permissions.
49 *
50 * @param fileOutputPrefix The file output prefix.
51 * @throws ApplicationException If the output directory is invalid.
52 */
53 static void checkOutputDirectory(File fileOutputPrefix) {
54 final File reportDir = fileOutputPrefix.getAbsoluteFile().getParentFile();
55 if (!reportDir.exists() ||
56 !reportDir.isDirectory() ||
57 !reportDir.canWrite()) {
58 throw new ApplicationException("Invalid output directory: " + reportDir);
59 }
60 }
61
62 /**
63 * Builds the command for the sub-process.
64 *
65 * @param executable The executable file.
66 * @param executableArguments The executable arguments.
67 * @return the command
68 * @throws ApplicationException If the executable path cannot be resolved
69 */
70 static List<String> buildSubProcessCommand(File executable,
71 List<String> executableArguments) {
72 final ArrayList<String> command = new ArrayList<>();
73 try {
74 command.add(executable.getCanonicalPath());
75 } catch (final IOException ex) {
76 // Not expected to happen as the file has been tested to exist
77 throw new ApplicationException("Cannot resolve executable path: " + ex.getMessage(), ex);
78 }
79 command.addAll(executableArguments);
80 return command;
81 }
82
83 /**
84 * Get the exit value from the process, waiting at most for 1 second, otherwise kill the process
85 * and return {@code null}.
86 *
87 * <p>This should be used when it is expected the process has completed.</p>
88 *
89 * @param process The process.
90 * @return The exit value.
91 * @see Process#destroy()
92 */
93 static Integer getExitValue(Process process) {
94 return getExitValue(process, DEFAULT_TIMEOUT_MILLIS);
95 }
96
97 /**
98 * Get the exit value from the process, waiting at most for the given time, otherwise
99 * kill the process and return {@code null}.
100 *
101 * <p>This should be used when it is expected the process has completed. If the timeout
102 * expires an error message is logged before the process is killed.</p>
103 *
104 * @param process The process.
105 * @param timeoutMillis The timeout (in milliseconds).
106 * @return The exit value.
107 * @see Process#destroy()
108 */
109 static Integer getExitValue(Process process, long timeoutMillis) {
110 final long startTime = System.currentTimeMillis();
111 long remaining = timeoutMillis;
112
113 while (remaining > 0) {
114 try {
115 return process.exitValue();
116 } catch (final IllegalThreadStateException ex) {
117 try {
118 Thread.sleep(Math.min(remaining + 1, 100));
119 } catch (final InterruptedException e) {
120 // Reset interrupted status and stop waiting
121 Thread.currentThread().interrupt();
122 break;
123 }
124 }
125 remaining = timeoutMillis - (System.currentTimeMillis() - startTime);
126 }
127
128 LogUtils.error("Failed to obtain exit value after %d ms, forcing termination", timeoutMillis);
129
130 // Not finished so kill it
131 process.destroy();
132
133 return null;
134 }
135 }