8182050: assert(_whole_heap.contains(p)) failed: Attempt to access p out of bounds of card marking array's _whole_heap
authortschatzl
Thu, 23 Nov 2017 15:51:06 +0100
changeset 48102 08be4c1e540e
parent 48101 02f9be87cf5c
child 48103 26dbe08d1c17
8182050: assert(_whole_heap.contains(p)) failed: Attempt to access p out of bounds of card marking array's _whole_heap Summary: Ignore zero-sized MemRegions to invalidate in G1SATBCardTableLoggingModRefBS::invalidate() Reviewed-by: ehelin, sjohanss
src/hotspot/share/gc/g1/g1SATBCardTableModRefBS.cpp
test/hotspot/jtreg/gc/g1/TestInvalidateArrayCopy.java
--- a/src/hotspot/share/gc/g1/g1SATBCardTableModRefBS.cpp	Thu Nov 23 15:51:06 2017 +0100
+++ b/src/hotspot/share/gc/g1/g1SATBCardTableModRefBS.cpp	Thu Nov 23 15:51:06 2017 +0100
@@ -175,6 +175,9 @@
 
 void
 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr) {
+  if (mr.is_empty()) {
+    return;
+  }
   volatile jbyte* byte = byte_for(mr.start());
   jbyte* last_byte = byte_for(mr.last());
   Thread* thr = Thread::current();
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/gc/g1/TestInvalidateArrayCopy.java	Thu Nov 23 15:51:06 2017 +0100
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2017, 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 TestInvalidateArrayCopy
+ * @bug 8182050
+ * @summary Check that benign (0-sized) out of heap bounds card table invalidations do not assert.
+ * @requires vm.gc.G1
+ * @requires vm.debug
+ * @key gc
+ * @run main/othervm -XX:NewSize=1M -Xlog:gc -XX:MaxNewSize=1m -XX:-UseTLAB -XX:OldSize=63M -XX:MaxHeapSize=64M TestInvalidateArrayCopy
+ */
+
+// The test allocates zero-sized arrays of j.l.O and tries to arraycopy random data into it so
+// that the asserting post barrier calls are executed. It assumes that G1 allocates eden regions
+// at the top of the heap for this problem to occur.
+public class TestInvalidateArrayCopy {
+
+    static final int NumIterations = 1000000;
+
+    // "Random" source data to "copy" into the target.
+    static Object[] sourceArray = new Object[10];
+
+    public static void main(String[] args) {
+        for (int i = 0; i < NumIterations; i++) {
+            Object[] x = new Object[0];
+            // Make sure that the compiler can't optimize out the above allocations.
+            if (i % (NumIterations / 10) == 0) {
+                System.out.println(x);
+            }
+            System.arraycopy(sourceArray, 0, x, 0, Math.min(x.length, sourceArray.length));
+        }
+    }
+}