1 /* 2 * Copyright (c) 2000, 2010, 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 // All heaps contains a "permanent generation," containing permanent 26 // (reflective) objects. This is like a regular generation in some ways, 27 // but unlike one in others, and so is split apart. 28 29 class Generation; 30 class GenRemSet; 31 class CSpaceCounters; 32 33 // PermGen models the part of the heap used to allocate class meta-data. 34 35 class PermGen : public CHeapObj { 36 friend class VMStructs; 37 protected: 38 size_t _capacity_expansion_limit; // maximum expansion allowed without a 39 // full gc occurring 40 void set_capacity_expansion_limit(size_t limit) { 41 assert_locked_or_safepoint(Heap_lock); 42 _capacity_expansion_limit = limit; 43 } 44 45 HeapWord* mem_allocate_in_gen(size_t size, Generation* gen); 46 // Along with mem_allocate_in_gen() above, implements policy for 47 // "scheduling" allocation/expansion/collection of the perm gen. 48 // The virtual method request_...() below can be overridden by 49 // subtypes that want to implement a different expansion/collection 50 // policy from the default provided. 51 virtual HeapWord* request_expand_and_allocate(Generation* gen, size_t size, 52 GCCause::Cause prev_cause); 53 54 public: 55 enum Name { 56 MarkSweepCompact, MarkSweep, ConcurrentMarkSweep 57 }; 58 59 // Permanent allocation (initialized) 60 virtual HeapWord* mem_allocate(size_t size) = 0; 61 62 // Mark sweep support 63 virtual void compute_new_size() = 0; 64 65 // Ideally, we would use MI (IMHO) but we'll do delegation instead. 66 virtual Generation* as_gen() const = 0; 67 68 virtual void oop_iterate(OopClosure* cl) { 69 Generation* g = as_gen(); 70 assert(g != NULL, "as_gen() NULL"); 71 g->oop_iterate(cl); 72 } 73 74 virtual void object_iterate(ObjectClosure* cl) { 75 Generation* g = as_gen(); 76 assert(g != NULL, "as_gen() NULL"); 77 g->object_iterate(cl); 78 } 79 80 // Performance Counter support 81 virtual void update_counters() { 82 Generation* g = as_gen(); 83 assert(g != NULL, "as_gen() NULL"); 84 g->update_counters(); 85 } 86 };