1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.maven.surefire.booter;
20
21 import javax.annotation.Nonnull;
22
23 /**
24 * Immutable object which encapsulates PID and elapsed time (Unix) or start time (Windows).
25 * <br>
26 * Methods
27 * ({@link #getPID()}, {@link #getTime()}, {@link #isTimeBefore(ProcessInfo)}, {@link #isTimeEqualTo(ProcessInfo)})
28 * throw {@link IllegalStateException}
29 * if {@link #canUse()} returns {@code false} or {@link #isError()} returns {@code true}.
30 *
31 * @author <a href="mailto:tibordigana@apache.org">Tibor Digana (tibor17)</a>
32 * @since 2.20.1
33 */
34 final class ProcessInfo {
35 static final ProcessInfo INVALID_PROCESS_INFO = new ProcessInfo(null, 0);
36 static final ProcessInfo ERR_PROCESS_INFO = new ProcessInfo(null, 0);
37
38 /**
39 * On Unix we do not get PID due to the command is interested only to etime of PPID:
40 * <br>
41 * <pre>/bin/ps -o etime= -p 123</pre>
42 */
43 static @Nonnull ProcessInfo unixProcessInfo(String pid, long etime) {
44 return new ProcessInfo(pid, etime);
45 }
46
47 static @Nonnull ProcessInfo windowsProcessInfo(String pid, long startTimestamp) {
48 return new ProcessInfo(pid, startTimestamp);
49 }
50
51 /**
52 * Creates process info from ProcessHandle API data.
53 *
54 * @param pid the process ID
55 * @param startTimeMillis the process start time in epoch milliseconds
56 * @return a new ProcessInfo instance
57 */
58 static @Nonnull ProcessInfo processHandleInfo(String pid, long startTimeMillis) {
59 return new ProcessInfo(pid, startTimeMillis);
60 }
61
62 private final String pid;
63 private final long time;
64
65 private ProcessInfo(String pid, long time) {
66 this.pid = pid;
67 this.time = time;
68 }
69
70 boolean canUse() {
71 return !isError();
72 }
73
74 boolean isInvalid() {
75 return this == INVALID_PROCESS_INFO;
76 }
77
78 boolean isError() {
79 return this == ERR_PROCESS_INFO;
80 }
81
82 String getPID() {
83 checkValid();
84 return pid;
85 }
86
87 long getTime() {
88 checkValid();
89 return time;
90 }
91
92 boolean isTimeEqualTo(ProcessInfo that) {
93 checkValid();
94 that.checkValid();
95 return time == that.time;
96 }
97
98 boolean isTimeBefore(ProcessInfo that) {
99 checkValid();
100 that.checkValid();
101 return time < that.time;
102 }
103
104 private void checkValid() {
105 if (!canUse()) {
106 throw new IllegalStateException("invalid process info");
107 }
108 }
109 }