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 template <class T> inline void ParScanWeakRefClosure::do_oop_work(T* p) { 26 assert (!oopDesc::is_null(*p), "null weak reference?"); 27 oop obj = oopDesc::load_decode_heap_oop_not_null(p); 28 // weak references are sometimes scanned twice; must check 29 // that to-space doesn't already contain this object 30 if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) { 31 // we need to ensure that it is copied (see comment in 32 // ParScanClosure::do_oop_work). 33 klassOop objK = obj->klass(); 34 markOop m = obj->mark(); 35 oop new_obj; 36 if (m->is_marked()) { // Contains forwarding pointer. 37 new_obj = ParNewGeneration::real_forwardee(obj); 38 } else { 39 size_t obj_sz = obj->size_given_klass(objK->klass_part()); 40 new_obj = ((ParNewGeneration*)_g)->copy_to_survivor_space(_par_scan_state, 41 obj, obj_sz, m); 42 } 43 oopDesc::encode_store_heap_oop_not_null(p, new_obj); 44 } 45 } 46 47 inline void ParScanWeakRefClosure::do_oop_nv(oop* p) { ParScanWeakRefClosure::do_oop_work(p); } 48 inline void ParScanWeakRefClosure::do_oop_nv(narrowOop* p) { ParScanWeakRefClosure::do_oop_work(p); } 49 50 template <class T> inline void ParScanClosure::par_do_barrier(T* p) { 51 assert(generation()->is_in_reserved(p), "expected ref in generation"); 52 assert(!oopDesc::is_null(*p), "expected non-null object"); 53 oop obj = oopDesc::load_decode_heap_oop_not_null(p); 54 // If p points to a younger generation, mark the card. 55 if ((HeapWord*)obj < gen_boundary()) { 56 rs()->write_ref_field_gc_par(p, obj); 57 } 58 } 59 60 template <class T> 61 inline void ParScanClosure::do_oop_work(T* p, 62 bool gc_barrier, 63 bool root_scan) { 64 assert((!Universe::heap()->is_in_reserved(p) || 65 generation()->is_in_reserved(p)) 66 && (generation()->level() == 0 || gc_barrier), 67 "The gen must be right, and we must be doing the barrier " 68 "in older generations."); 69 T heap_oop = oopDesc::load_heap_oop(p); 70 if (!oopDesc::is_null(heap_oop)) { 71 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 72 if ((HeapWord*)obj < _boundary) { 73 assert(!_g->to()->is_in_reserved(obj), "Scanning field twice?"); 74 // OK, we need to ensure that it is copied. 75 // We read the klass and mark in this order, so that we can reliably 76 // get the size of the object: if the mark we read is not a 77 // forwarding pointer, then the klass is valid: the klass is only 78 // overwritten with an overflow next pointer after the object is 79 // forwarded. 80 klassOop objK = obj->klass(); 81 markOop m = obj->mark(); 82 oop new_obj; 83 if (m->is_marked()) { // Contains forwarding pointer. 84 new_obj = ParNewGeneration::real_forwardee(obj); 85 oopDesc::encode_store_heap_oop_not_null(p, new_obj); 86 } else { 87 size_t obj_sz = obj->size_given_klass(objK->klass_part()); 88 new_obj = _g->copy_to_survivor_space(_par_scan_state, obj, obj_sz, m); 89 oopDesc::encode_store_heap_oop_not_null(p, new_obj); 90 if (root_scan) { 91 // This may have pushed an object. If we have a root 92 // category with a lot of roots, can't let the queue get too 93 // full: 94 (void)_par_scan_state->trim_queues(10 * ParallelGCThreads); 95 } 96 } 97 if (gc_barrier) { 98 // Now call parent closure 99 par_do_barrier(p); 100 } 101 } 102 } 103 } 104 105 inline void ParScanWithBarrierClosure::do_oop_nv(oop* p) { ParScanClosure::do_oop_work(p, true, false); } 106 inline void ParScanWithBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, true, false); } 107 108 inline void ParScanWithoutBarrierClosure::do_oop_nv(oop* p) { ParScanClosure::do_oop_work(p, false, false); } 109 inline void ParScanWithoutBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, false, false); }