undefect. CWE-407 — 63 sites patched across 27 ecosystems

Authors: russell@unturf.com · brackishbert@gmail.com · foxhop.net · TimeHexOn.com

Patches, unit tests, benchmarks, whitepaper, and outreach briefs.
Public domain — no copyright claimed. Use freely.

test/jdk/java/io/BufferedReader/ReadLineSync.java

@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2005, 2010, 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 5073414
+ * @summary Ensure that there is no race condition in BufferedReader.readLine()
+ *          when a line is terminated by '\r\n' is read by multiple threads.
+ */
+
+import java.io.*;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+public class ReadLineSync {
+
+    public static int lineCount = 0;
+
+    public static void main( String[] args ) throws Exception {
+
+        String dir = System.getProperty(".", ".");
+        File f = new File(dir, "test.txt");
+        createFile(f);
+        f.deleteOnExit();
+
+        BufferedReader reader = new BufferedReader(
+                                new FileReader(f));
+        try {
+            int threadCount = 2;
+
+            ExecutorService es = Executors.newFixedThreadPool(threadCount);
+
+            for (int i=0; i < threadCount; i++)
+                es.execute(new BufferedReaderConsumer(reader));
+
+            // Wait for the tasks to complete
+            es.shutdown();
+            while (!es.awaitTermination(60, TimeUnit.SECONDS));
+        } finally {
+            reader.close();
+        }
+    }
+
+    static class BufferedReaderConsumer extends Thread {
+        BufferedReader reader;
+
+        public BufferedReaderConsumer( BufferedReader reader ) {
+            this.reader = reader;
+        }
+
+        public void run() {
+            try {
+                String record = reader.readLine();
+
+                if ( record == null ) {
+                    // if the first thread is too fast the second will hit
+                    // this which is ok
+                    System.out.println( "File already finished" );
+                    return;
+                }
+
+                if ( record.length() == 0 ) {
+                    // usually it comes out here indicating the first read
+                    // done by the second thread to run failed
+                    System.out.println("Empty string on first read." +
+                                Thread.currentThread().getName() );
+                }
+
+                while ( record != null ) {
+                    lineCount++;
+
+                    // Verify the token count
+                    if ( record.length() == 0 ) {
+                        // very occasionally it will fall over here
+                        throw new Exception( "Invalid tokens with string '" +
+                                record + "' on line " + lineCount );
+                    }
+                    record = reader.readLine();
+                }
+            }
+            catch ( Exception e ) {
+                e.printStackTrace();
+            }
+        }
+    }
+
+
+    // Create a relatively big file
+
+    private static void createFile(File f) throws IOException {
+        BufferedWriter w = new BufferedWriter(
+                           new FileWriter(f));
+        int count = 10000;
+        while (count > 0) {
+
+            w.write("abcd \r\n");
+            w.write("efg \r\n");
+            w.write("hijk \r\n");
+            w.write("lmnop \r\n");
+            w.write("qrstuv \r\n");
+            w.write("wxy and z \r\n");
+            w.write("now you \r\n");
+            w.write("know your \r\n");
+            w.write("abc \r\n");
+            w.write("next time \r\n");
+            w.write("want you \r\n");
+            w.write("sing with me \r\n");
+
+            count--;
+        }
+        w.close();
+    }
+}