jdk8-mips64-public/hotspot: src/share/vm/memory/metadataFactory.hpp@2c022e432e10 (annotated)

src/share/vm/memory/metadataFactory.hpp@2c022e432e10 (annotated)

src/share/vm/memory/metadataFactory.hpp

Fri, 20 Sep 2013 10:53:28 +0200

author: stefank
date: Fri, 20 Sep 2013 10:53:28 +0200
changeset 5769: 2c022e432e10
parent 4457: 59a58e20dc60
child 5896: d37a0525c0fe
permissions: -rw-r--r--

8024974: Incorrect use of GC_locker::is_active()
Summary: SymbolTable and StringTable can make calls to GC_locker::is_active() outside a safepoint. This isn't safe because the GC_locker active state (lock count) is only updated at a safepoint and only remains valid as long as _needs_gc is true. However, outside a safepoint_needs_gc can change to false at any time, which makes it impossible to do a correct call to is_active() in that context. In this case these calls can just be removed since the input argument to basic_add() should never be on the heap and so there's no need to check the GC_locker state. This change also adjusts the assert() in is_active() to makes sure all calls to this function are always done under a safepoint.
Reviewed-by: brutisso, dcubed
Contributed-by: per.liden@oracle.com

 /*
  * Copyright (c) 2010, 2012, 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
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 #ifndef SHARE_VM_MEMORY_METADATAFACTORY_HPP
 #define SHARE_VM_MEMORY_METADATAFACTORY_HPP
 #include "utilities/array.hpp"
 #include "utilities/exceptions.hpp"
 #include "utilities/globalDefinitions.hpp"
 class MetadataFactory : AllStatic {
  public:
   template <typename T>
   static Array<T>* new_array(ClassLoaderData* loader_data, int length, TRAPS) {
     // The "true" argument is because all metadata arrays are read only when
     // dumped to the shared archive
     return new (loader_data, length, /*read_only*/true, THREAD) Array<T>(length);
   }
   template <typename T>
   static Array<T>* new_array(ClassLoaderData* loader_data, int length, T value, TRAPS) {
     Array<T>* array = new_array<T>(loader_data, length, CHECK_NULL);
     for (int i = 0; i < length; i++) {
       array->at_put(i, value);
     }
     return array;
   }
   template <typename T>
   static Array<T>* new_writeable_array(ClassLoaderData* loader_data, int length, TRAPS) {
     return new (loader_data, length, /*read_only*/false, THREAD) Array<T>(length);
   }
   template <typename T>
   static Array<T>* new_writeable_array(ClassLoaderData* loader_data, int length, T value, TRAPS) {
     Array<T>* array = new_writeable_array<T>(loader_data, length, CHECK_NULL);
     for (int i = 0; i < length; i++) {
       array->at_put(i, value);
     }
     return array;
   }
   template <typename T>
   static void free_array(ClassLoaderData* loader_data, Array<T>* data) {
     if (data != NULL) {
       assert(loader_data != NULL, "shouldn't pass null");
       int size = data->size();
       if (DumpSharedSpaces) {
         loader_data->ro_metaspace()->deallocate((MetaWord*)data, size, false);
       } else {
         loader_data->metaspace_non_null()->deallocate((MetaWord*)data, size, false);
       }
     }
   }
   // Deallocation method for metadata
   template <class T>
   static void free_metadata(ClassLoaderData* loader_data, T md) {
     if (md != NULL) {
       assert(loader_data != NULL, "shouldn't pass null");
       int size = md->size();
       // Call metadata's deallocate function which will call deallocate fields
       assert(!DumpSharedSpaces, "cannot deallocate metadata when dumping CDS archive");
       assert(!md->on_stack(), "can't deallocate things on stack");
       md->deallocate_contents(loader_data);
       loader_data->metaspace_non_null()->deallocate((MetaWord*)md, size, md->is_klass());
     }
   }
 };
 #endif // SHARE_VM_MEMORY_METADATAFACTORY_HPP

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src/share/vm/memory/metadataFactory.hpp@2c022e432e10 (annotated)

src/share/vm/memory/metadataFactory.hpp