6631352: File{OutputStream,Writer} should implement atomic append mode using FILE_APPEND_DATA (win)

Reviewed-by: alanb, iris

jdk/test/java/io/FileOutputStream/AtomicAppend.java

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/*
+ * @test
+ * @bug 6631352
+ * @summary Check that appends are atomic
+ */
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.TimeUnit;
+
+public class AtomicAppend {
+    // Before the fix for
+    // 6631352: Implement atomic append mode using FILE_APPEND_DATA (win)
+    // this would fail intermittently on windows
+    void test(String[] args) throws Throwable {
+        final int nThreads = 10;
+        final int writes = 1000;
+        final File file = new File("foo");
+        file.delete();
+        try {
+            final ExecutorService es = Executors.newFixedThreadPool(nThreads);
+            for (int i = 0; i < nThreads; i++)
+                es.execute(new Runnable() { public void run() {
+                    try {
+                        FileOutputStream s = new FileOutputStream(file, true);
+                        for (int j = 0; j < 1000; j++) {
+                            s.write((int) 'x');
+                            s.flush();
+                        }
+                        s.close();
+                    } catch (Throwable t) { unexpected(t); }}});
+            es.shutdown();
+            es.awaitTermination(10L, TimeUnit.MINUTES);
+            equal(file.length(), (long) (nThreads * writes));
+        } finally {
+            file.delete();
+        }
+    }
+
+    //--------------------- Infrastructure ---------------------------
+    volatile int passed = 0, failed = 0;
+    void pass() {passed++;}
+    void fail() {failed++; Thread.dumpStack();}
+    void fail(String msg) {System.err.println(msg); fail();}
+    void unexpected(Throwable t) {failed++; t.printStackTrace();}
+    void check(boolean cond) {if (cond) pass(); else fail();}
+    void equal(Object x, Object y) {
+        if (x == null ? y == null : x.equals(y)) pass();
+        else fail(x + " not equal to " + y);}
+    public static void main(String[] args) throws Throwable {
+        new AtomicAppend().instanceMain(args);}
+    void instanceMain(String[] args) throws Throwable {
+        try {test(args);} catch (Throwable t) {unexpected(t);}
+        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
+        if (failed > 0) throw new AssertionError("Some tests failed");}
+}