1 /*
   2  * Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/stringTable.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "code/codeCache.hpp"
  29 #include "gc_interface/collectedHeap.inline.hpp"
  30 #include "memory/sharedHeap.hpp"
  31 #include "oops/oop.inline.hpp"
  32 #include "runtime/atomic.inline.hpp"
  33 #include "runtime/fprofiler.hpp"
  34 #include "runtime/java.hpp"
  35 #include "utilities/copy.hpp"
  36 #include "utilities/workgroup.hpp"
  37 
  38 SharedHeap::SharedHeap() :
  39   CollectedHeap(),
  40   _workers(NULL)
  41 {
  42   if (UseConcMarkSweepGC || UseG1GC) {
  43     _workers = new FlexibleWorkGang("GC Thread", ParallelGCThreads,
  44                             /* are_GC_task_threads */true,
  45                             /* are_ConcurrentGC_threads */false);
  46     if (_workers == NULL) {
  47       vm_exit_during_initialization("Failed necessary allocation.");
  48     } else {
  49       _workers->initialize_workers();
  50     }
  51   }
  52 }
  53 
  54 SharedHeap::StrongRootsScope::StrongRootsScope(SharedHeap* heap, bool activate)
  55   : MarkScope(activate), _sh(heap)
  56 {
  57   if (_active) {
  58     Threads::change_thread_claim_parity();
  59     // Zero the claimed high water mark in the StringTable
  60     StringTable::clear_parallel_claimed_index();
  61   }
  62 }
  63 
  64 SharedHeap::StrongRootsScope::~StrongRootsScope() {
  65   Threads::assert_all_threads_claimed();
  66 }