[Misc] Polish rcm API

Summary:
- Replace null with root() to represent root container for consistency
- Support rcm inheritance by Thread.inheritedResourceContainer

Test Plan: jtreg com/alibaba/rcm/ multi-tenent/

Reviewed-by: luchsh, tanghaoth90

Issue: https://github.com/alibaba/dragonwell8/issues/95

src/share/classes/java/lang/System.java

@@ -1315,6 +1315,11 @@ public final class System {
             public AbstractResourceContainer getResourceContainer(Thread thread) {
                 return thread.resourceContainer;
             }
+
+            @Override
+            public AbstractResourceContainer getInheritedResourceContainer(Thread thread) {
+                return thread.inheritedResourceContainer;
+            }
         });
     }
 }

src/share/classes/java/lang/Thread.java

@@ -227,6 +227,11 @@ class Thread implements Runnable {
      */
     AbstractResourceContainer resourceContainer;
 
+    /**
+     * {@code ResourceContainer} inherited from parent
+     */
+    AbstractResourceContainer inheritedResourceContainer;
+
     private static synchronized long nextThreadID() {
         return ++threadSeqNumber;
     }
@@ -439,6 +444,7 @@ class Thread implements Runnable {
 
         /* com.alibaba.rcm API */
         this.resourceContainer = AbstractResourceContainer.root();
+        this.inheritedResourceContainer = parent.resourceContainer;
 
         /* Set the tenant container */
         if (VM.isBooted() && TenantGlobals.isTenantEnabled()) {
@@ -788,6 +794,8 @@ class Thread implements Runnable {
         blocker = null;
         uncaughtExceptionHandler = null;
         inheritedTenantContainer = null;
+        resourceContainer = null;
+        inheritedResourceContainer = null;
     }
 
     /**

src/share/classes/sun/misc/JavaLangAccess.java

@@ -145,4 +145,9 @@ public interface JavaLangAccess {
      * Get the reference to the thread attached {@code ResourceContainer}
      */
     AbstractResourceContainer getResourceContainer(Thread thread);
+
+    /**
+     * Get the reference to the thread's inherited {@code ResourceContainer}
+     */
+    AbstractResourceContainer getInheritedResourceContainer(Thread thread);
 }

test/com/alibaba/rcm/TestConfiguration.java

@@ -46,14 +46,16 @@ public class TestConfiguration {
                 MyResourceType.MY_RESOURCE1.newConstraint(),
                 MyResourceType.MY_RESOURCE2.newConstraint()));
 
-
         assertTrue(iterator2Stream(mc.operations.iterator()).collect(Collectors.toSet())
-                .equals(new HashSet<>(Arrays.asList("update MY_RESOURCE1", "update MY_RESOURCE2"))));
+                .equals(new HashSet<>(Arrays.asList("update " + MyResourceType.MY_RESOURCE1.toString(),
+                                                    "update " + MyResourceType.MY_RESOURCE2.toString()))));
 
         mc.updateConstraint(MyResourceType.MY_RESOURCE2.newConstraint());
 
         assertTrue(iterator2Stream(mc.operations.iterator()).collect(Collectors.toSet())
-                .equals(new HashSet<>(Arrays.asList("update MY_RESOURCE1", "update MY_RESOURCE2", "update MY_RESOURCE2"))));
+                .equals(new HashSet<>(Arrays.asList("update " + MyResourceType.MY_RESOURCE1.toString(),
+                                                    "update " + MyResourceType.MY_RESOURCE2.toString(),
+                                                    "update " + MyResourceType.MY_RESOURCE2.toString()))));
     }
 
     private static <T> Stream<T> iterator2Stream(Iterator<T> iterator) {

test/com/alibaba/rcm/TestInherit.java

@@ -28,6 +28,7 @@
  */
 
 import com.alibaba.rcm.ResourceContainer;
+import demo.RCInheritedThreadFactory;
 import demo.MyResourceFactory;
 
 import java.util.Collections;
@@ -44,23 +45,23 @@ public class TestInherit {
         rc.run(() -> {
             assertEQ(ResourceContainer.current(), rc);
             FutureTask<ResourceContainer> f1 = new FutureTask<>(ResourceContainer::current);
-            new Thread(f1).start();
+            RCInheritedThreadFactory.INSTANCE.newThread(f1).start();
             assertEQ(get(f1), rc);
             FutureTask<ResourceContainer> f2 = new FutureTask<>(ResourceContainer::current);
-            ResourceContainer.root().run(() -> new Thread(f2).start());
+            ResourceContainer.root().run(() -> RCInheritedThreadFactory.INSTANCE.newThread(f2).start());
             assertEQ(get(f2), ResourceContainer.root());
         });
 
         // thread is bound to it's parent thread(the thread called Thread::init())
         // not dependent on where Thread::start() called.
         FutureTask<ResourceContainer> f3 = new FutureTask<>(ResourceContainer::current);
-        Thread t3 = new Thread(f3);
+        Thread t3 = RCInheritedThreadFactory.INSTANCE.newThread(f3);
         // Thread::init is called in root()
         rc.run(t3::start);
         assertEQ(get(f3), ResourceContainer.root());
 
         FutureTask<ResourceContainer> f4 = new FutureTask<>(ResourceContainer::current);
-        FutureTask<Thread> newThread = new FutureTask<>(() -> new Thread(f4));
+        FutureTask<Thread> newThread = new FutureTask<>(() -> RCInheritedThreadFactory.INSTANCE.newThread(f4));
         // Thread::init is called in container
         rc.run(newThread);
         get(newThread).start();

test/com/alibaba/rcm/TestInheritedContainer.java

+/*
+ * Copyright (c) 2020 Alibaba Group Holding Limited. 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. Alibaba designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ *
+ */
+
+/*
+ * @test
+ * @summary Test ONLY inheritedResourceContainer is inherited from parent
+ * @library /lib/testlibrary
+ * @run main TestInheritedContainer
+ */
+
+import com.alibaba.rcm.ResourceContainer;
+import demo.MyResourceFactory;
+import sun.misc.JavaLangAccess;
+import sun.misc.SharedSecrets;
+
+import java.util.Collections;
+import java.util.concurrent.CompletableFuture;
+
+import static jdk.testlibrary.Asserts.assertEQ;
+
+
+public class TestInheritedContainer {
+    public static void main(String[] args) throws Exception {
+        ResourceContainer rc = MyResourceFactory.INSTANCE.createContainer(Collections.emptyList());
+        JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
+        rc.run(() -> {
+            try {
+                assertEQ(ResourceContainer.root(),
+                        CompletableFuture.supplyAsync(() -> JLA.getResourceContainer(Thread.currentThread())).get());
+                assertEQ(rc,
+                        CompletableFuture.supplyAsync(() -> JLA.getInheritedResourceContainer(Thread.currentThread())).get());
+            } catch (Exception e) {
+                throw new AssertionError(e);
+            }
+        });
+    }
+}

test/com/alibaba/rcm/TestRootNotNull.java

+/*
+ * Copyright (c) 2020 Alibaba Group Holding Limited. 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. Alibaba designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ *
+ */
+
+/*
+ * @test
+ * @summary Test default ResourceContainer is root() instead of null
+ * @library /lib/testlibrary
+ * @run main TestRootNotNull
+ */
+
+import sun.misc.SharedSecrets;
+
+import static jdk.testlibrary.Asserts.assertNotNull;
+
+public class TestRootNotNull {
+    public static void main(String[] args) {
+        assertNotNull(SharedSecrets.getJavaLangAccess().getResourceContainer(Thread.currentThread()));
+    }
+}

test/com/alibaba/rcm/demo/RCInheritedThreadFactory.java

+/*
+ * Copyright (c) 2020 Alibaba Group Holding Limited. 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. Alibaba designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ *
+ */
+
+package demo;
+
+import com.alibaba.rcm.internal.AbstractResourceContainer;
+import sun.misc.JavaLangAccess;
+import sun.misc.SharedSecrets;
+
+import java.util.concurrent.ThreadFactory;
+
+public class RCInheritedThreadFactory implements ThreadFactory {
+    public final static ThreadFactory INSTANCE = new RCInheritedThreadFactory();
+    private final static JavaLangAccess JLA = SharedSecrets.getJavaLangAccess();
+
+    @Override
+    public Thread newThread(Runnable r) {
+        return new Thread(() -> {
+            AbstractResourceContainer irc = JLA.getInheritedResourceContainer(Thread.currentThread());
+            if (irc != null) {
+                irc.run(r);
+            } else {
+                r.run();
+            }
+        });
+    }
+}