1 /* 2 * Copyright (c) 2002, 2008, 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 inline void PSScavenge::save_to_space_top_before_gc() { 26 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); 27 _to_space_top_before_gc = heap->young_gen()->to_space()->top(); 28 } 29 30 template <class T> inline bool PSScavenge::should_scavenge(T* p) { 31 T heap_oop = oopDesc::load_heap_oop(p); 32 if (oopDesc::is_null(heap_oop)) return false; 33 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop); 34 return PSScavenge::is_obj_in_young((HeapWord*)obj); 35 } 36 37 template <class T> 38 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) { 39 if (should_scavenge(p)) { 40 oop obj = oopDesc::load_decode_heap_oop_not_null(p); 41 // Skip objects copied to to_space since the scavenge started. 42 HeapWord* const addr = (HeapWord*)obj; 43 return addr < to_space_top_before_gc() || addr >= to_space->end(); 44 } 45 return false; 46 } 47 48 template <class T> 49 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) { 50 if (check_to_space) { 51 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); 52 return should_scavenge(p, heap->young_gen()->to_space()); 53 } 54 return should_scavenge(p); 55 } 56 57 // Attempt to "claim" oop at p via CAS, push the new obj if successful 58 // This version tests the oop* to make sure it is within the heap before 59 // attempting marking. 60 template <class T> 61 inline void PSScavenge::copy_and_push_safe_barrier(PSPromotionManager* pm, 62 T* p) { 63 assert(should_scavenge(p, true), "revisiting object?"); 64 65 oop o = oopDesc::load_decode_heap_oop_not_null(p); 66 oop new_obj = o->is_forwarded() 67 ? o->forwardee() 68 : pm->copy_to_survivor_space(o); 69 oopDesc::encode_store_heap_oop_not_null(p, new_obj); 70 71 // We cannot mark without test, as some code passes us pointers 72 // that are outside the heap. 73 if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) && 74 Universe::heap()->is_in_reserved(p)) { 75 if (PSScavenge::is_obj_in_young((HeapWord*)new_obj)) { 76 card_table()->inline_write_ref_field_gc(p, new_obj); 77 } 78 } 79 }