8338064: Give better error for ConcurrentHashTable corruption

Reviewed-by: dholmes, shade

Author: coleenp

src/hotspot/share/utilities/concurrentHashTable.hpp

@@ -65,6 +65,7 @@ class ConcurrentHashTable : public CHeapObj<F> {
   // the InternalTable or user-defined memory.
   class Node {
    private:
+    DEBUG_ONLY(size_t _saved_hash);
     Node * volatile _next;
     VALUE _value;
    public:
@@ -77,6 +78,10 @@ class ConcurrentHashTable : public CHeapObj<F> {
     Node* next() const;
     void set_next(Node* node)         { _next = node; }
     Node* const volatile * next_ptr() { return &_next; }
+#ifdef ASSERT
+    size_t saved_hash() const         { return _saved_hash; }
+    void set_saved_hash(size_t hash)  { _saved_hash = hash; }
+#endif
 
     VALUE* value()                    { return &_value; }
 

src/hotspot/share/utilities/concurrentHashTable.inline.hpp

@@ -679,7 +679,9 @@ inline bool ConcurrentHashTable<CONFIG, F>::
         // Keep in odd list
         odd = aux->next_ptr();
       } else {
-        fatal("aux_index does not match even or odd indices");
+        const char* msg = "Cannot resize table: Node hash code has changed possibly due to corruption of the contents.";
+        DEBUG_ONLY(fatal("%s Node hash code changed from " SIZE_FORMAT " to " SIZE_FORMAT, msg, aux->saved_hash(), aux_hash);)
+        NOT_DEBUG(fatal("%s", msg);)
       }
     }
     aux = aux_next;
@@ -892,6 +894,7 @@ inline bool ConcurrentHashTable<CONFIG, F>::
   size_t i = 0;
   uintx hash = lookup_f.get_hash();
   Node* new_node = Node::create_node(_context, value, nullptr);
+  DEBUG_ONLY(new_node->set_saved_hash(hash);)
 
   while (true) {
     {
@@ -1117,6 +1120,7 @@ inline bool ConcurrentHashTable<CONFIG, F>::
   Bucket* bucket = get_bucket_in(table, hash);
   assert(!bucket->have_redirect() && !bucket->is_locked(), "bad");
   Node* new_node = Node::create_node(_context, value, bucket->first());
+  DEBUG_ONLY(new_node->set_saved_hash(hash);)
   if (!bucket->cas_first(new_node, bucket->first())) {
     assert(false, "bad");
   }

test/hotspot/jtreg/runtime/stringtable/StringTableCorruptionTest.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2024, 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 8333356
+ * @summary Verify new error message for corrupting string table contents.
+ * @requires vm.flagless
+ * @modules java.base/java.lang:open
+ * @library /test/lib
+ * @modules java.base/jdk.internal.misc
+ * @run driver StringTableCorruptionTest test
+ */
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
+
+import jdk.test.lib.process.OutputAnalyzer;
+import jdk.test.lib.process.ProcessTools;
+
+public class StringTableCorruptionTest {
+    public static void main(String[] args) throws Exception {
+        if (args.length > 0) {
+            ProcessBuilder pb = ProcessTools.createLimitedTestJavaProcessBuilder("--add-opens", "java.base/java.lang=ALL-UNNAMED",
+                                                             "-XX:-CreateCoredumpOnCrash", "StringTableCorruptionTest");
+            OutputAnalyzer output = new OutputAnalyzer(pb.start());
+            output.shouldContain("Node hash code has changed possibly due to corruption of the contents.");
+            output.shouldNotHaveExitValue(0);
+            return;
+        }
+
+        Field f = String.class.getDeclaredField("value");
+        f.setAccessible(true);
+        f.set("s1".intern(), f.get("s2"));
+        for (int i = 0; i < 4_000_000; i++) {
+            ("s_" + i).intern();
+        }
+    }
+}