jdk/test/java/lang/ProcessBuilder/SkipTest.java
changeset 39061 0a7abfc4f4b0
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/java/lang/ProcessBuilder/SkipTest.java	Fri Jun 17 15:57:28 2016 -0400
@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8155808
+ * @run main SkipTest
+ * @summary verify skip method of Process Input Stream
+ */
+
+import java.io.BufferedOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+public class SkipTest {
+    private static final String javaExe =
+            System.getProperty("java.home") +
+                    File.separator + "bin" + File.separator + "java";
+
+    private static final String classpath =
+            System.getProperty("java.class.path");
+
+    static final int BLOCK_SIZE = 10000;
+
+
+    public static void main(String[] args) throws Throwable {
+
+        // Start a Process to generate the test data to stdout and stderr
+        ProcessBuilder pb = new ProcessBuilder(javaExe, "-classpath", classpath, "SkipTest$GenerateData");
+        System.out.printf("cmd: %s%n", pb.command());
+        Process process = pb.start();
+
+        /*
+         * Verify the data expected is received mixing reads and skip.
+         */
+        try (InputStream in = process.getInputStream()) {
+
+            // Note: Process.getInputStream() actually returns a BufferedInputStream whose
+            // skip() method works perfectly, partially obscuring the bug. Only when the
+            // BufferedInputStream's buffer is drained, and it passes the skip() call to
+            // the underlying native stream, does the problem occur.
+
+            long n = in.skip(-1);
+            if (n != 0) {
+                throw new AssertionError("skip(-1) should return 0");
+            }
+            n = in.skip(0);
+            if (n != 0) {
+                throw new AssertionError("skip(0) should return 0");
+            }
+
+            // Now iterate all the data blocks
+            int header;
+            for (int expectedHeader = 'A'; (header = in.read()) != -1; expectedHeader++) {
+                // The header byte should be simple 'A' to 'Z'.
+                // When the bug hits, we will get lowercase letters instead.
+                if (header != expectedHeader) {
+                    throw new AssertionError("header char wrong, expected: " +
+                            expectedHeader + ", actual: " + header);
+                }
+
+                // Handle the data bytes.
+                // If the correct number of bytes are not skipped,
+                // then subsequent reads become out-of-sync;
+                int remaining = BLOCK_SIZE;
+                do {
+                    remaining -= in.skip(remaining);
+                } while (remaining != 0);
+            }
+            n = in.skip(1);
+            if (n != 0) {
+                throw new AssertionError("skip(1) at eof should return 0");
+            }
+        }
+
+        /**
+         * Do the same for the standard error stream.
+         */
+        try (InputStream in = process.getErrorStream()) {
+            long n = in.skip(-1);
+            if (n != 0) {
+                throw new AssertionError("skip(-1) should return 0");
+            }
+            n = in.skip(0);
+            if (n != 0) {
+                throw new AssertionError("skip(0) should return 0");
+            }
+
+            // Now iterate all the data blocks
+            int header;
+            for (int expectedHeader = 'A'; (header = in.read()) != -1; expectedHeader++) {
+                // The header byte should be simple 'A' to 'Z'.
+                // When the bug hits, we will get lowercase letters instead.
+                if (header != expectedHeader) {
+                    throw new AssertionError("header char wrong, expected: " +
+                            expectedHeader + ", actual: " + header);
+                }
+
+                // Handle the data bytes.
+                // If the correct number of bytes are not skipped,
+                // then subsequent reads become out-of-sync;
+                int remaining = BLOCK_SIZE;
+                do {
+                    remaining -= in.skip(remaining);
+                } while (remaining != 0);
+            }
+            n = in.skip(1);
+            if (n != 0) {
+                throw new AssertionError("skip(1) at eof should return 0");
+            }
+        }
+    }
+
+    /**
+     * Alternate main to generate the test data to standard output
+     * and standard error.
+     */
+    static class GenerateData {
+
+        public static void main(String[] args) {
+            // Generate test data containing a series of data blocks of length BLOCK_SIZE,
+            // each with a one-byte header. For example's sake, the "header" is a capital letter,
+            // and the "data" is the lowercase version of that letter repeated BLOCK_SIZE times:
+            try (OutputStream out = new BufferedOutputStream(System.out)) {
+                for (int header = 'A'; header <= 'Z'; header++) {
+                    out.write(header);
+
+                    int data = Character.toLowerCase(header);
+                    for (int i = 0; i < BLOCK_SIZE; i++) {
+                        out.write(data);
+                    }
+                }
+            } catch (IOException ioe) {
+                ioe.printStackTrace();
+                System.exit(1);
+            }
+            // Generate the same data to the error output
+            try (OutputStream err = new BufferedOutputStream(System.err)) {
+                for (int header = 'A'; header <= 'Z'; header++) {
+                    err.write(header);
+
+                    int data = Character.toLowerCase(header);
+                    for (int i = 0; i < BLOCK_SIZE; i++) {
+                        err.write(data);
+                    }
+                }
+            } catch (IOException ioe) {
+                ioe.printStackTrace();
+                System.exit(1);
+            }
+        }
+    }
+}