1 /*
2 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 /* @test
25 * @bug 4763384
26 * @summary Ensure that piped input always works with exec'd processes
27 */
28
29 import java.io.*;
30
31
32 /**
33 * This class demonstrates a regression in java1.4.1 in the handling of the
34 * Process OutputStream (exec'd process stdin). The subprocess completes 100%
35 * of the time in 1.4, but about only about 50% of the time under 1.4.1. Issue
36 * exists for client JVM, Linux Redhat 6.2 not sure about other variants of
37 * Linux or other OSes, or server JVM.
38 */
39
40 public class ExecWithInput {
41
42 private static final String CAT = "/bin/cat";
43 private static final int N = 200;
44
45 static int go(int i) throws Exception {
46 /*
47 * Execute /bin/cat supplying two lines of input. cat should
48 * read the input lines and copy them to stdout. On completion,
49 * p.waitFor should return and the exit status is printed and this
50 * program exits. Under 1.4.1, cat sometimes gets stuck on a pipe
51 * read and never terminates.
52 */
53 //Process p = Runtime.getRuntime().exec(new String[] { CAT } );
54 Process p = Runtime.getRuntime().exec(CAT);
55
56 String input = i + ": line 1\n" + i + ": line 2\n";
57 StringBufferInputStream in = new StringBufferInputStream(input);
58 // create threads to handle I/O streams
59 IO ioIn = new IO("stdin", in, p.getOutputStream());
60 IO ioOut = new IO("stdout", p.getInputStream(), System.out);
61 IO ioErr = new IO("stderr", p.getErrorStream(), System.err);
62
63 // wait for process to exit
64 return p.waitFor();
65 }
66
67 public static void main(String[] args) throws Exception {
68 if (!System.getProperty("os.name").equals("Linux"))
69 return;
70 if (File.separatorChar == '\\') {
71 // no /bin/cat on windows
72 return;
73 }
74 for (int i = 0; i < N; i++)
75 go(i);
76 }
77
78 /**
79 * Handle IO. Thread is started in constructor.
80 */
81 static class IO extends Thread {
82
83 private InputStream in;
84 private OutputStream out;
85
86 IO(String name, InputStream in, OutputStream out)
87 {
88 this.in = in;
89 this.out = out;
90 setName(name);
91 start();
92 }
93
94 public void run() {
95 try {
96 int c;
97 byte[] buf = new byte[8192];
98 int n;
99 while ((n = in.read(buf)) != -1) {
100 out.write(buf, 0, n);
101 out.flush();
102 }
103 /*
104 while ((c = in.read()) != -1) {
105 out.write(c);
106 if (c == '\n')
107 out.flush();
108 }
109 out.flush();
110 */
111 } catch (IOException e) {
112 e.printStackTrace();
113 } finally {
114 if (!System.out.equals(out) && !System.err.equals(out)) {
115 // Note: in order to get an exec'd java process to
116 // see EOF on input, it is necessary to close stdin
117 if (out != null) {
118 try { out.close(); } catch (Exception e) {
119 e.printStackTrace();
120 }
121 }
122 }
123 }
124 }
125 }
126
127 }