1 /* 2 * Copyright (c) 2007, 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 class CardTableRS; // fwd decl 26 class ConcurrentMarkSweepGeneration; 27 28 // A PermGen implemented with a CMS space, collected by a CMS collector. 29 class CMSPermGen: public PermGen { 30 friend class VMStructs; 31 32 protected: 33 // The "generation" view. 34 ConcurrentMarkSweepGeneration* _gen; 35 36 // Override default implementation from PermGen 37 virtual HeapWord* request_expand_and_allocate(Generation* gen, size_t size, 38 GCCause::Cause prev_cause); 39 40 public: 41 CMSPermGen(ReservedSpace rs, size_t initial_byte_size, 42 CardTableRS* ct, FreeBlockDictionary::DictionaryChoice); 43 44 HeapWord* mem_allocate(size_t size); 45 46 void compute_new_size(); 47 48 Generation* as_gen() const { return _gen; } 49 }; 50 51 // This is the "generation" view of a CMSPermGen. 52 class CMSPermGenGen: public ConcurrentMarkSweepGeneration { 53 // Abstractly, this is a subtype that gets access to protected fields. 54 friend class CMSPermGen; 55 public: 56 CMSPermGenGen(ReservedSpace rs, size_t initial_byte_size, 57 int level, CardTableRS* ct): 58 // See comments in the constructor for CompactibleFreeListSpace 59 // regarding not using adaptive free lists for a perm gen. 60 ConcurrentMarkSweepGeneration(rs, initial_byte_size, // MinPermHeapExapnsion 61 level, ct, false /* use adaptive freelists */, 62 (FreeBlockDictionary::DictionaryChoice)CMSDictionaryChoice) 63 {} 64 65 void initialize_performance_counters(); 66 67 const char* name() const { 68 return "concurrent-mark-sweep perm gen"; 69 } 70 71 const char* short_name() const { 72 return "CMS Perm"; 73 } 74 75 bool must_be_youngest() const { return false; } 76 bool must_be_oldest() const { return false; } 77 };