--- a/src/java.base/share/classes/java/net/URL.java Wed Nov 21 09:40:19 2018 -0500
+++ b/src/java.base/share/classes/java/net/URL.java Wed Nov 21 15:09:27 2018 +0000
@@ -1393,39 +1393,39 @@
}
}
- synchronized (streamHandlerLock) {
- if (handler == null) {
- // Try the built-in protocol handler
- handler = defaultFactory.createURLStreamHandler(protocol);
- } else {
- URLStreamHandler handler2 = null;
-
- // Check again with hashtable just in case another
- // thread created a handler since we last checked
- handler2 = handlers.get(protocol);
+ if (handler == null) {
+ // Try the built-in protocol handler
+ handler = defaultFactory.createURLStreamHandler(protocol);
+ }
- if (handler2 != null) {
- return handler2;
- }
+ synchronized (streamHandlerLock) {
+ URLStreamHandler handler2 = null;
- // Check with factory if another thread set a
- // factory since our last check
- if (!checkedWithFactory && (fac = factory) != null) {
- handler2 = fac.createURLStreamHandler(protocol);
- }
+ // Check again with hashtable just in case another
+ // thread created a handler since we last checked
+ handler2 = handlers.get(protocol);
- if (handler2 != null) {
- // The handler from the factory must be given more
- // importance. Discard the default handler that
- // this thread created.
- handler = handler2;
- }
+ if (handler2 != null) {
+ return handler2;
}
- // Insert this handler into the hashtable
- if (handler != null) {
- handlers.put(protocol, handler);
+ // Check with factory if another thread set a
+ // factory since our last check
+ if (!checkedWithFactory && (fac = factory) != null) {
+ handler2 = fac.createURLStreamHandler(protocol);
}
+
+ if (handler2 != null) {
+ // The handler from the factory must be given more
+ // importance. Discard the default handler that
+ // this thread created.
+ handler = handler2;
+ }
+ }
+
+ // Insert this handler into the hashtable
+ if (handler != null) {
+ handlers.put(protocol, handler);
}
return handler;
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/net/URL/RacyHandler.java Wed Nov 21 15:09:27 2018 +0000
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2018, 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.
+ */
+
+import java.io.IOException;
+import java.lang.reflect.*;
+import java.net.URL;
+import java.net.URLConnection;
+import java.net.URLStreamHandler;
+import java.util.concurrent.CountDownLatch;
+
+/*
+ * @test
+ * @bug 8213942
+ * @summary URLStreamHandler initialization race
+ * @run main/othervm RacyHandler
+ * @run main/othervm RacyHandler
+ * @run main/othervm RacyHandler
+ */
+
+/*
+ * This test makes reasonable effort to reproduce the race.
+ * Run repeatedly to ensure correctness.
+ */
+public class RacyHandler {
+ static volatile boolean factorySet = false;
+ static int NUM_THREADS = 2;
+ static CountDownLatch cdl = new CountDownLatch(NUM_THREADS + 1);
+
+ public static void main(String[] args) {
+ RacyHandler tester = new RacyHandler();
+ tester.runTest();
+ }
+
+ public void runTest() {
+ new Thread(() -> {
+ try {
+ cdl.await();
+ URL.setURLStreamHandlerFactory(proto -> new CustomHttpHandler());
+ factorySet = true;
+ } catch (Exception ignore) { }
+ }).start();
+ cdl.countDown();
+
+ for (int i = 0; i < NUM_THREADS; i++) {
+ new Thread(() -> {
+ try {
+ cdl.await();
+ while (!factorySet) {
+ // trigger URL class load
+ getURLStreamHandler();
+ }
+ } catch (Exception ignore) { }
+ }).start();
+ cdl.countDown();
+ }
+
+ // wait for the factory to be set
+ while (!factorySet) { }
+ // The sleep seems to help trigger the failure
+ try {
+ Thread.sleep(500);
+ } catch (InterruptedException ie) {
+ }
+
+ URLStreamHandler httpHandler = getURLStreamHandler();
+ System.out.println("After setting factory URL handlers: http " + httpHandler);
+ if (!(httpHandler instanceof CustomHttpHandler))
+ throw new RuntimeException("FAILED: Incorrect handler type");
+ }
+
+ /*
+ * This is just so we can see what we get for the URLStreamHandler back
+ * from the factory to verify whether it really is using our Handler
+ * or something else...
+ */
+ public URLStreamHandler getURLStreamHandler() {
+ try {
+ Method method = URL.class.getDeclaredMethod("getURLStreamHandler",
+ String.class);
+ method.setAccessible(true);
+ return (URLStreamHandler) method.invoke(null, "http");
+ } catch (Exception e) {
+ return null;
+ }
+ }
+
+ class CustomHttpHandler extends URLStreamHandler {
+ @Override
+ protected URLConnection openConnection(URL u) throws IOException {
+ return null;
+ }
+ }
+}
\ No newline at end of file