8231387: java.security.Provider.getService returns random result due to race condition with mutating methods in the same class

Synchronize access to legacyMap in Provider.getService.

Reviewed-by: valeriep

Author: TianminShi

src/java.base/share/classes/java/security/Provider.java

@@ -1255,9 +1255,9 @@ public Service getService(String type, String algorithm) {
         }
         synchronized (this) {
             ensureLegacyParsed();
-        }
-        if (legacyMap != null && !legacyMap.isEmpty()) {
-            return legacyMap.get(key);
+            if (legacyMap != null && !legacyMap.isEmpty()) {
+                return legacyMap.get(key);
+            }
         }
         return null;
     }

test/jdk/java/security/Provider/GetServiceRace.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2019, 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 8231387
+ * @library ../testlibrary
+ * @summary make sure getService() avoids a race
+ * @author Tianmin Shi
+ */
+
+import java.security.Provider;
+
+public class GetServiceRace {
+
+    private static final Provider testProvider;
+    static {
+        testProvider = new Provider("MyProvider", 1.0, "test") {
+        };
+        testProvider.put("CertificateFactory.Fixed", "MyCertificateFactory");
+    }
+
+    private static final int NUMBER_OF_RETRIEVERS = 3;
+    private static final int TEST_TIME_MS = 1000;
+
+    public static boolean testFailed = false;
+
+    public static void main(String[] args) throws Exception {
+        Updater updater = new Updater();
+        updater.start();
+        Retriever [] retrievers = new Retriever[NUMBER_OF_RETRIEVERS];
+        for (int i=0; i<retrievers.length; i++) {
+            retrievers[i] = new Retriever();
+            retrievers[i].start();
+        }
+        Thread.sleep(TEST_TIME_MS);
+        System.out.println("Interrupt");
+        updater.interrupt();
+        updater.join();
+        for (int i=0; i<retrievers.length; i++) {
+            retrievers[i].interrupt();
+            retrievers[i].join();
+        }
+        System.out.println("Done");
+        if (testFailed) {
+            throw new Exception("Test Failed");
+        }
+        System.out.println("Test Passed");
+    }
+
+    private static class Updater extends Thread {
+        @Override
+        public void run() {
+            while (!isInterrupted()) {
+                testProvider.put("CertificateFactory.Added", "MyCertificateFactory");
+            }
+            System.out.println("Updater stopped");
+        }
+    }
+
+    private static class Retriever extends Thread {
+        @Override
+        public void run() {
+            while (!isInterrupted()) {
+                Provider.Service service = testProvider.getService("CertificateFactory", "Fixed");
+                if (service == null) {
+                    if (!testFailed) {
+                        System.err.println("CertificateFactory.Fixed is NULL");
+                        testFailed = true;
+                    }
+                } else {
+                    //System.out.println("CertificateFactory.Fixed is good");
+                }
+            }
+            System.out.println("Retriever stopped");
+        }
+    }
+}