8029443: 'assert(klass->is_loader_alive(_is_alive)) failed: must be alive' during VM_CollectForMetadataAllocation
Summary: Added missing metadata relocation to 'loadConP_no_oop_cheap' on Sparc if the pointer is referring to a Klass. Added jtreg test.
Reviewed-by: kvn, roland
--- a/hotspot/src/cpu/sparc/vm/sparc.ad Tue Aug 05 15:02:10 2014 -0700
+++ b/hotspot/src/cpu/sparc/vm/sparc.ad Wed Aug 06 08:47:40 2014 +0200
@@ -6184,7 +6184,11 @@
ins_cost(DEFAULT_COST * 3/2);
format %{ "SET $con,$dst\t! non-oop ptr" %}
ins_encode %{
- __ set($con$$constant, $dst$$Register);
+ if (_opnds[1]->constant_reloc() == relocInfo::metadata_type) {
+ __ set_metadata_constant((Metadata*)$con$$constant, $dst$$Register);
+ } else {
+ __ set($con$$constant, $dst$$Register);
+ }
%}
ins_pipe(loadConP);
%}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/classUnloading/methodUnloading/TestMethodUnloading.java Wed Aug 06 08:47:40 2014 +0200
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2014, 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 sun.hotspot.WhiteBox;
+
+import java.lang.reflect.Method;
+import java.net.URL;
+import java.net.URLClassLoader;
+
+/*
+ * @test MethodUnloadingTest
+ * @bug 8029443
+ * @summary "Tests the unloading of methods to to class unloading"
+ * @library /testlibrary /testlibrary/whitebox
+ * @build TestMethodUnloading
+ * @build WorkerClass
+ * @run main ClassFileInstaller sun.hotspot.WhiteBox
+ * @run main/othervm -Xbootclasspath/a:. -XX:+IgnoreUnrecognizedVMOptions -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -XX:-BackgroundCompilation -XX:-UseCompressedOops -XX:+UseParallelGC -XX:CompileOnly=TestMethodUnloading::doWork TestMethodUnloading
+ */
+public class TestMethodUnloading {
+ private static final String workerClassName = "WorkerClass";
+ private static int work = -1;
+
+ private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
+ private static int COMP_LEVEL_SIMPLE = 1;
+ private static int COMP_LEVEL_FULL_OPTIMIZATION = 4;
+
+ /**
+ * Does some work by either using the workerClass or locally producing values.
+ * @param workerClass Class performing some work (will be unloaded)
+ * @param useWorker If true the workerClass is used
+ */
+ static private void doWork(Class<?> workerClass, boolean useWorker) throws InstantiationException, IllegalAccessException {
+ if (useWorker) {
+ // Create a new instance
+ Object worker = workerClass.newInstance();
+ // We would like to call a method of WorkerClass here but we cannot cast to WorkerClass
+ // because the class was loaded by a different class loader. One solution would be to use
+ // reflection but since we want C2 to implement the call as an optimized IC we call
+ // Object::hashCode() here which actually calls WorkerClass::hashCode().
+ // C2 will then implement this call as an optimized IC that points to a to-interpreter stub
+ // referencing the Method* for WorkerClass::hashCode().
+ work = worker.hashCode();
+ if (work != 42) {
+ new RuntimeException("Work not done");
+ }
+ } else {
+ // Do some important work here
+ work = 1;
+ }
+ }
+
+ /**
+ * Makes sure that method is compiled by forcing compilation if not yet compiled.
+ * @param m Method to be checked
+ */
+ static private void makeSureIsCompiled(Method m) {
+ // Make sure background compilation is disabled
+ if (WHITE_BOX.getBooleanVMFlag("BackgroundCompilation")) {
+ throw new RuntimeException("Background compilation enabled");
+ }
+
+ // Check if already compiled
+ if (!WHITE_BOX.isMethodCompiled(m)) {
+ // If not, try to compile it with C2
+ if(!WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_FULL_OPTIMIZATION)) {
+ // C2 compiler not available, try to compile with C1
+ WHITE_BOX.enqueueMethodForCompilation(m, COMP_LEVEL_SIMPLE);
+ }
+ // Because background compilation is disabled, method should now be compiled
+ if(!WHITE_BOX.isMethodCompiled(m)) {
+ throw new RuntimeException(m + " not compiled");
+ }
+ }
+ }
+
+ /**
+ * This test creates stale Method* metadata in a to-interpreter stub of an optimized IC.
+ *
+ * The following steps are performed:
+ * (1) A workerClass is loaded by a custom class loader
+ * (2) The method doWork that calls a method of the workerClass is compiled. The call
+ * is implemented as an optimized IC calling a to-interpreted stub. The to-interpreter
+ * stub contains a Method* to a workerClass method.
+ * (3) Unloading of the workerClass is enforced. The to-interpreter stub now contains a dead Method*.
+ * (4) Depending on the implementation of the IC, the compiled version of doWork should still be
+ * valid. We call it again without using the workerClass.
+ */
+ static public void main(String[] args) throws Exception {
+ // (1) Create a custom class loader with no parent class loader
+ URL url = TestMethodUnloading.class.getProtectionDomain().getCodeSource().getLocation();
+ URLClassLoader loader = new URLClassLoader(new URL[] {url}, null);
+
+ // Load worker class with custom class loader
+ Class<?> workerClass = Class.forName(workerClassName, true, loader);
+
+ // (2) Make sure all paths of doWork are profiled and compiled
+ for (int i = 0; i < 100000; ++i) {
+ doWork(workerClass, true);
+ doWork(workerClass, false);
+ }
+
+ // Make sure doWork is compiled now
+ Method doWork = TestMethodUnloading.class.getDeclaredMethod("doWork", Class.class, boolean.class);
+ makeSureIsCompiled(doWork);
+
+ // (3) Throw away class loader and reference to workerClass to allow unloading
+ loader.close();
+ loader = null;
+ workerClass = null;
+
+ // Force garbage collection to trigger unloading of workerClass
+ // Dead reference to WorkerClass::hashCode triggers JDK-8029443
+ WHITE_BOX.fullGC();
+
+ // (4) Depending on the implementation of the IC, the compiled version of doWork
+ // may still be valid here. Execute it without a workerClass.
+ doWork(null, false);
+ if (work != 1) {
+ throw new RuntimeException("Work not done");
+ }
+
+ doWork(Object.class, false);
+ }
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/classUnloading/methodUnloading/WorkerClass.java Wed Aug 06 08:47:40 2014 +0200
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2014, 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.
+ */
+
+/**
+ * Worker class that is dynamically loaded/unloaded by TestMethodUnloading.
+ */
+public class WorkerClass {
+ /**
+ * We override hashCode here to be able to access this implementation
+ * via an Object reference (we cannot cast to WorkerClass).
+ */
+ @Override
+ public int hashCode() {
+ return 42;
+ }
+}
+