1 /* 2 * Copyright (c) 2016, 2017, 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 "gc/g1/g1ConcurrentMark.inline.hpp" 27 #include "gc/g1/g1ConcurrentMarkObjArrayProcessor.inline.hpp" 28 29 void G1CMObjArrayProcessor::push_array_slice(HeapWord* what) { 30 G1TaskQueueEntry entry(what); 31 _task->push(entry); 32 } 33 34 size_t G1CMObjArrayProcessor::process_array_slice(objArrayOop obj, HeapWord* start_from, size_t remaining) { 35 size_t words_to_scan = MIN2(remaining, ObjArrayMarkingStride); 36 37 if (remaining > ObjArrayMarkingStride) { 38 push_array_slice(start_from + ObjArrayMarkingStride); 39 } 40 41 // Then process current area. 42 MemRegion mr(start_from, words_to_scan); 43 return _task->scan_objArray(obj, mr); 44 } 45 46 size_t G1CMObjArrayProcessor::process_obj(oop obj) { 47 assert(should_be_sliced(obj), "Must be an array object %d and large " SIZE_FORMAT, obj->is_objArray(), (size_t)obj->size()); 48 49 return process_array_slice(objArrayOop(obj), (HeapWord*)obj, (size_t)objArrayOop(obj)->size()); 50 } 51 52 size_t G1CMObjArrayProcessor::process_slice(HeapWord* slice) { 53 54 // Find the start address of the objArrayOop. 55 // Shortcut the BOT access if the given address is from a humongous object. The BOT 56 // slide is fast enough for "smaller" objects in non-humongous regions, but is slower 57 // than directly using heap region table. 58 G1CollectedHeap* g1h = G1CollectedHeap::heap(); 59 HeapRegion* r = g1h->heap_region_containing(slice); 60 61 HeapWord* const start_address = r->is_humongous() ? 62 r->humongous_start_region()->bottom() : 63 g1h->block_start(slice); 64 65 assert(oop(start_address)->is_objArray(), "Address " PTR_FORMAT " does not refer to an object array ", p2i(start_address)); 66 assert(start_address < slice, 67 "Object start address " PTR_FORMAT " must be smaller than decoded address " PTR_FORMAT, 68 p2i(start_address), 69 p2i(slice)); 70 71 objArrayOop objArray = objArrayOop(start_address); 72 73 size_t already_scanned = slice - start_address; 74 size_t remaining = objArray->size() - already_scanned; 75 76 return process_array_slice(objArray, slice, remaining); 77 }