src/share/vm/classfile/symbolTable.cpp

rev 6140 : 8029075: String deduplication in G1
Implementation of JEP 192, http://openjdk.java.net/jeps/192

*** 1,7 ****
  /*
!  * Copyright (c) 1997, 2013, 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.
--- 1,7 ----
  /*
!  * 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.
*** 33,42 ****
--- 33,45 ----
  #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;
*** 726,735 ****
--- 729,747 ----
      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