8006960: hotspot, "impossible" assertion failure
Summary: Escape state of allocated object should be always adjusted after it was passed to a method.
Reviewed-by: kvn
--- a/hotspot/src/share/vm/ci/bcEscapeAnalyzer.cpp Wed Feb 25 12:33:43 2015 +0100
+++ b/hotspot/src/share/vm/ci/bcEscapeAnalyzer.cpp Mon Mar 02 13:40:40 2015 +0100
@@ -43,7 +43,7 @@
#define TRACE_BCEA(level, code)
#endif
-// Maintain a map of which aguments a local variable or
+// Maintain a map of which arguments a local variable or
// stack slot may contain. In addition to tracking
// arguments, it tracks two special values, "allocated"
// which represents any object allocated in the current
@@ -319,14 +319,16 @@
bool must_record_dependencies = false;
for (i = arg_size - 1; i >= 0; i--) {
ArgumentMap arg = state.raw_pop();
- if (!is_argument(arg))
+ // Check if callee arg is a caller arg or an allocated object
+ bool allocated = arg.contains_allocated();
+ if (!(is_argument(arg) || allocated))
continue;
for (int j = 0; j < _arg_size; j++) {
if (arg.contains(j)) {
_arg_modified[j] |= analyzer._arg_modified[i];
}
}
- if (!is_arg_stack(arg)) {
+ if (!(is_arg_stack(arg) || allocated)) {
// arguments have already been recognized as escaping
} else if (analyzer.is_arg_stack(i) && !analyzer.is_arg_returned(i)) {
set_method_escape(arg);
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/test/compiler/escapeAnalysis/TestEscapeThroughInvoke.java Mon Mar 02 13:40:40 2015 +0100
@@ -0,0 +1,74 @@
+/*
+ * 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 8073956
+ * @summary Tests C2 EA with allocated object escaping through a call.
+ * @run main/othervm -XX:CompileCommand=dontinline,TestEscapeThroughInvoke::create TestEscapeThroughInvoke
+ */
+public class TestEscapeThroughInvoke {
+ private A a;
+
+ public static void main(String[] args) {
+ TestEscapeThroughInvoke test = new TestEscapeThroughInvoke();
+ test.a = new A(42);
+ // Make sure run gets compiled by C2
+ for (int i = 0; i < 100_000; ++i) {
+ test.run();
+ }
+ }
+
+ private void run() {
+ // Allocate something to trigger EA
+ new Object();
+ // Create a new escaping instance of A and
+ // verify that it is always equal to 'a.saved'.
+ A escapingA = create(42);
+ a.check(escapingA);
+ }
+
+ // Create and return a new instance of A that escaped through 'A::saveInto'.
+ // The 'dummy' parameters are needed to avoid EA skipping the methods.
+ private A create(Integer dummy) {
+ A result = new A(dummy);
+ result.saveInto(a, dummy); // result escapes into 'a' here
+ return result;
+ }
+}
+
+class A {
+ private A saved;
+
+ public A(Integer dummy) { }
+
+ public void saveInto(A other, Integer dummy) {
+ other.saved = this;
+ }
+
+ public void check(A other) {
+ if (this.saved != other) {
+ throw new RuntimeException("TEST FAILED: Objects not equal.");
+ }
+ }
+}