src/share/vm/classfile/symbolTable.cpp

rev 6083 : 8029075: String deduplication in G1
Implementation of JEP 192, http://openjdk.java.net/jeps/192

@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 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.

@@ -33,10 +33,13 @@
 #include "memory/gcLocker.inline.hpp"
 #include "oops/oop.inline.hpp"
 #include "oops/oop.inline2.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "utilities/hashtable.inline.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc_implementation/g1/g1StringDedup.hpp"
+#endif
 
 // --------------------------------------------------------------------------
 
 // the number of buckets a thread claims
 const int ClaimChunkSize = 32;

@@ -726,10 +729,19 @@
     string = string_or_null;
   } else {
     string = java_lang_String::create_from_unicode(name, len, CHECK_NULL);
   }
 
+#if INCLUDE_ALL_GCS
+  if (G1StringDedup::is_enabled()) {
+    // Deduplicate the string before it is interned. Note that we should never
+    // deduplicate a string after it has been interned. Doing so will counteract
+    // compiler optimizations done on e.g. interned string literals.
+    G1StringDedup::deduplicate(string());
+  }
+#endif
+
   // Grab the StringTable_lock before getting the_table() because it could
   // change at safepoint.
   MutexLocker ml(StringTable_lock, THREAD);
 
   // Otherwise, add to symbol to table