CHA for abstract methods.

Add the ability to devirtualize abstract method invocation if
an abstract method has only one implementation. Only support in JIT
mode currently.

Test: new testcase and ART_TEST_JIT=true m -j20 test-art-host-run-test
Change-Id: I43da03a9fa9a73840f5eaf207c6611e0913a7f66
diff --git a/test/616-cha-abstract/src/Main.java b/test/616-cha-abstract/src/Main.java
new file mode 100644
index 0000000..e1d7db1
--- /dev/null
+++ b/test/616-cha-abstract/src/Main.java
@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+abstract class Base {
+  abstract void foo(int i);
+
+  void printError(String msg) {
+    System.out.println(msg);
+  }
+}
+
+class Main1 extends Base {
+  void foo(int i) {
+    if (i != 1) {
+      printError("error1");
+    }
+  }
+}
+
+class Main2 extends Main1 {
+  void foo(int i) {
+    if (i != 2) {
+      printError("error2");
+    }
+  }
+}
+
+public class Main {
+  static Main1 sMain1;
+  static Main1 sMain2;
+
+  static boolean sIsOptimizing = true;
+  static boolean sHasJIT = true;
+  static volatile boolean sOtherThreadStarted;
+
+  private static void assertSingleImplementation(Class<?> clazz, String method_name, boolean b) {
+    if (hasSingleImplementation(clazz, method_name) != b) {
+      System.out.println(clazz + "." + method_name +
+          " doesn't have single implementation value of " + b);
+    }
+  }
+
+  // sMain1.foo() will be always be Main1.foo() before Main2 is loaded/linked.
+  // So sMain1.foo() can be devirtualized to Main1.foo() and be inlined.
+  // After Dummy.createMain2() which links in Main2, live testOverride() on stack
+  // should be deoptimized.
+  static void testOverride(boolean createMain2, boolean wait, boolean setHasJIT) {
+    if (setHasJIT) {
+      if (isInterpreted()) {
+        sHasJIT = false;
+      }
+      return;
+    }
+
+    if (createMain2 && (sIsOptimizing || sHasJIT)) {
+      assertIsManaged();
+    }
+
+    sMain1.foo(sMain1.getClass() == Main1.class ? 1 : 2);
+
+    if (createMain2) {
+      // Wait for the other thread to start.
+      while (!sOtherThreadStarted);
+      // Create an Main2 instance and assign it to sMain2.
+      // sMain1 is kept the same.
+      sMain2 = Dummy.createMain2();
+      // Wake up the other thread.
+      synchronized(Main.class) {
+        Main.class.notify();
+      }
+    } else if (wait) {
+      // This is the other thread.
+      synchronized(Main.class) {
+        sOtherThreadStarted = true;
+        // Wait for Main2 to be linked and deoptimization is triggered.
+        try {
+          Main.class.wait();
+        } catch (Exception e) {
+        }
+      }
+    }
+
+    // There should be a deoptimization here right after Main2 is linked by
+    // calling Dummy.createMain2(), even though sMain1 didn't change.
+    // The behavior here would be different if inline-cache is used, which
+    // doesn't deoptimize since sMain1 still hits the type cache.
+    sMain1.foo(sMain1.getClass() == Main1.class ? 1 : 2);
+    if ((createMain2 || wait) && sHasJIT && !sIsOptimizing) {
+      // This method should be deoptimized right after Main2 is created.
+      assertIsInterpreted();
+    }
+
+    if (sMain2 != null) {
+      sMain2.foo(sMain2.getClass() == Main1.class ? 1 : 2);
+    }
+  }
+
+  // Test scenarios under which CHA-based devirtualization happens,
+  // and class loading that overrides a method can invalidate compiled code.
+  public static void main(String[] args) {
+    System.loadLibrary(args[0]);
+
+    if (isInterpreted()) {
+      sIsOptimizing = false;
+    }
+
+    // sMain1 is an instance of Main1. Main2 hasn't bee loaded yet.
+    sMain1 = new Main1();
+
+    ensureJitCompiled(Main.class, "testOverride");
+    testOverride(false, false, true);
+
+    if (sHasJIT && !sIsOptimizing) {
+      assertSingleImplementation(Base.class, "foo", true);
+      assertSingleImplementation(Main1.class, "foo", true);
+    } else {
+      // Main2 is verified ahead-of-time so it's linked in already.
+    }
+
+    // Create another thread that also calls sMain1.foo().
+    // Try to test suspend and deopt another thread.
+    new Thread() {
+      public void run() {
+        testOverride(false, true, false);
+      }
+    }.start();
+
+    // This will create Main2 instance in the middle of testOverride().
+    testOverride(true, false, false);
+    assertSingleImplementation(Base.class, "foo", false);
+    assertSingleImplementation(Main1.class, "foo", false);
+  }
+
+  private static native void ensureJitCompiled(Class<?> itf, String method_name);
+  private static native void assertIsInterpreted();
+  private static native void assertIsManaged();
+  private static native boolean isInterpreted();
+  private static native boolean hasSingleImplementation(Class<?> clazz, String method_name);
+}
+
+// Put createMain2() in another class to avoid class loading due to verifier.
+class Dummy {
+  static Main1 createMain2() {
+    return new Main2();
+  }
+}