8072016: Array copy may cause infinite cycle of deoptimization/compilation

Summary: Infinite deoptimization/recompilation cycles in case of arraycopy with tightly coupled allocation
Reviewed-by: kvn, vlivanov

hotspot/src/share/vm/opto/graphKit.cpp

@@ -2819,8 +2819,12 @@ Node* GraphKit::maybe_cast_profiled_obj(Node* obj,
   if (type != NULL) {
     Deoptimization::DeoptReason class_reason = Deoptimization::Reason_speculate_class_check;
     Deoptimization::DeoptReason null_reason = Deoptimization::Reason_speculate_null_check;
+    ciMethod* trap_method = (sfpt == NULL) ? method() : sfpt->jvms()->method();
+    int trap_bci = (sfpt == NULL) ? bci() : sfpt->jvms()->bci();
+
     if (!too_many_traps(null_reason) && !too_many_recompiles(null_reason) &&
-        !too_many_traps(class_reason) && !too_many_recompiles(class_reason)) {
+        !C->too_many_traps(trap_method, trap_bci, class_reason) &&
+        !C->too_many_recompiles(trap_method, trap_bci, class_reason)) {
       Node* not_null_obj = NULL;
       // not_null is true if we know the object is not null and
       // there's no need for a null check

hotspot/src/share/vm/opto/library_call.cpp

@@ -4740,6 +4740,8 @@ bool LibraryCallKit::inline_arraycopy() {
   // tightly_coupled_allocation()
   AllocateArrayNode* alloc = tightly_coupled_allocation(dest, NULL);
 
+  ciMethod* trap_method = method();
+  int trap_bci = bci();
   SafePointNode* sfpt = NULL;
   if (alloc != NULL) {
     // The JVM state for uncommon traps between the allocation and
@@ -4764,6 +4766,9 @@ bool LibraryCallKit::inline_arraycopy() {
 
     sfpt->set_i_o(map()->i_o());
     sfpt->set_memory(map()->memory());
+
+    trap_method = jvms->method();
+    trap_bci = jvms->bci();
   }
 
   bool validated = false;
@@ -4868,7 +4873,7 @@ bool LibraryCallKit::inline_arraycopy() {
     }
   }
 
-  if (!too_many_traps(Deoptimization::Reason_intrinsic) && !src->is_top() && !dest->is_top()) {
+  if (!C->too_many_traps(trap_method, trap_bci, Deoptimization::Reason_intrinsic) && !src->is_top() && !dest->is_top()) {
     // validate arguments: enables transformation the ArrayCopyNode
     validated = true;
 

hotspot/test/compiler/arraycopy/TestArrayCopyNoInit.java

@@ -29,8 +29,6 @@
  *
  */
 
-import java.lang.invoke.*;
-
 public class TestArrayCopyNoInit {
 
     static int[] m1(int[] src) {
@@ -134,7 +132,7 @@ public class TestArrayCopyNoInit {
         return dest;
     }
 
-    static public void main(String[] args) throws Throwable {
+    static public void main(String[] args) {
         boolean success = true;
         int[] src = new int[10];
         TestArrayCopyNoInit[] src2 = new TestArrayCopyNoInit[10];

hotspot/test/compiler/arraycopy/TestArrayCopyNoInitDeopt.java

+/*
+ * Copyright (c) 2015, 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 8072016
+ * @summary Infinite deoptimization/recompilation cycles in case of arraycopy with tightly coupled allocation
+ * @library /testlibrary /../../test/lib /compiler/whitebox
+ * @build TestArrayCopyNoInitDeopt
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main ClassFileInstaller com.oracle.java.testlibrary.Platform
+ * @run main/othervm -Xmixed -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI
+ *                   -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:TypeProfileLevel=020
+ *                   TestArrayCopyNoInitDeopt
+ *
+ */
+
+
+import sun.hotspot.WhiteBox;
+import sun.hotspot.code.NMethod;
+import com.oracle.java.testlibrary.Platform;
+import java.lang.reflect.*;
+
+public class TestArrayCopyNoInitDeopt {
+
+    public static int[] m1(Object src) {
+        if (src == null) return null;
+        int[] dest = new int[10];
+        try {
+            System.arraycopy(src, 0, dest, 0, 10);
+        } catch (ArrayStoreException npe) {
+        }
+        return dest;
+    }
+
+    static Object m2_src(Object src) {
+        return src;
+    }
+
+    public static int[] m2(Object src) {
+        if (src == null) return null;
+        src = m2_src(src);
+        int[] dest = new int[10];
+        try {
+            System.arraycopy(src, 0, dest, 0, 10);
+        } catch (ArrayStoreException npe) {
+        }
+        return dest;
+    }
+
+    private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
+
+    static boolean deoptimize(Method method, Object src_obj) throws Exception {
+        for (int i = 0; i < 10; i++) {
+            method.invoke(null, src_obj);
+            if (!WHITE_BOX.isMethodCompiled(method)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    static public void main(String[] args) throws Exception {
+        if (Platform.isServer()) {
+            int[] src = new int[10];
+            Object src_obj = new Object();
+            Method method_m1 = TestArrayCopyNoInitDeopt.class.getMethod("m1", Object.class);
+            Method method_m2 = TestArrayCopyNoInitDeopt.class.getMethod("m2", Object.class);
+
+            // Warm up
+            for (int i = 0; i < 20000; i++) {
+                m1(src);
+            }
+
+            // And make sure m1 is compiled by C2
+            WHITE_BOX.enqueueMethodForCompilation(method_m1, CompilerWhiteBoxTest.COMP_LEVEL_FULL_OPTIMIZATION);
+
+            if (!WHITE_BOX.isMethodCompiled(method_m1)) {
+                throw new RuntimeException("m1 not compiled");
+            }
+
+            // should deoptimize for type check
+            if (!deoptimize(method_m1, src_obj)) {
+                throw new RuntimeException("m1 not deoptimized");
+            }
+
+            WHITE_BOX.enqueueMethodForCompilation(method_m1, CompilerWhiteBoxTest.COMP_LEVEL_FULL_OPTIMIZATION);
+
+            if (!WHITE_BOX.isMethodCompiled(method_m1)) {
+                throw new RuntimeException("m1 not recompiled");
+            }
+
+            if (deoptimize(method_m1, src_obj)) {
+                throw new RuntimeException("m1 deoptimized again");
+            }
+
+            // Same test as above but with speculative types
+
+            // Warm up & make sure we collect type profiling
+            for (int i = 0; i < 20000; i++) {
+                m2(src);
+            }
+
+            // And make sure m2 is compiled by C2
+            WHITE_BOX.enqueueMethodForCompilation(method_m2, CompilerWhiteBoxTest.COMP_LEVEL_FULL_OPTIMIZATION);
+
+            if (!WHITE_BOX.isMethodCompiled(method_m2)) {
+                throw new RuntimeException("m2 not compiled");
+            }
+
+            // should deoptimize for speculative type check
+            if (!deoptimize(method_m2, src_obj)) {
+                throw new RuntimeException("m2 not deoptimized");
+            }
+
+            WHITE_BOX.enqueueMethodForCompilation(method_m2, CompilerWhiteBoxTest.COMP_LEVEL_FULL_OPTIMIZATION);
+
+            if (!WHITE_BOX.isMethodCompiled(method_m2)) {
+                throw new RuntimeException("m2 not recompiled");
+            }
+
+            // should deoptimize for actual type check
+            if (!deoptimize(method_m2, src_obj)) {
+                throw new RuntimeException("m2 not deoptimized");
+            }
+
+            WHITE_BOX.enqueueMethodForCompilation(method_m2, CompilerWhiteBoxTest.COMP_LEVEL_FULL_OPTIMIZATION);
+
+            if (!WHITE_BOX.isMethodCompiled(method_m2)) {
+                throw new RuntimeException("m2 not recompiled");
+            }
+
+            if (deoptimize(method_m2, src_obj)) {
+                throw new RuntimeException("m2 deoptimized again");
+            }
+        }
+    }
+}