1/*
2 * Copyright (c) 2016, 2018, 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
29void G1CMObjArrayProcessor::push_array_slice(HeapWord* what) {
30 _task->push(G1TaskQueueEntry::from_slice(what));
31}
32
33size_t G1CMObjArrayProcessor::process_array_slice(objArrayOop obj, HeapWord* start_from, size_t remaining) {
34 size_t words_to_scan = MIN2(remaining, (size_t)ObjArrayMarkingStride);
35
36 if (remaining > ObjArrayMarkingStride) {
37 push_array_slice(start_from + ObjArrayMarkingStride);
38 }
39
40 // Then process current area.
41 MemRegion mr(start_from, words_to_scan);
42 return _task->scan_objArray(obj, mr);
43}
44
45size_t G1CMObjArrayProcessor::process_obj(oop obj) {
46 assert(should_be_sliced(obj), "Must be an array object %d and large " SIZE_FORMAT, obj->is_objArray(), (size_t)obj->size());
47
48 return process_array_slice(objArrayOop(obj), (HeapWord*)obj, (size_t)objArrayOop(obj)->size());
49}
50
51size_t G1CMObjArrayProcessor::process_slice(HeapWord* slice) {
52
53 // Find the start address of the objArrayOop.
54 // Shortcut the BOT access if the given address is from a humongous object. The BOT
55 // slide is fast enough for "smaller" objects in non-humongous regions, but is slower
56 // than directly using heap region table.
57 G1CollectedHeap* g1h = G1CollectedHeap::heap();
58 HeapRegion* r = g1h->heap_region_containing(slice);
59
60 HeapWord* const start_address = r->is_humongous() ?
61 r->humongous_start_region()->bottom() :
62 g1h->block_start(slice);
63
64 assert(oop(start_address)->is_objArray(), "Address " PTR_FORMAT " does not refer to an object array ", p2i(start_address));
65 assert(start_address < slice,
66 "Object start address " PTR_FORMAT " must be smaller than decoded address " PTR_FORMAT,
67 p2i(start_address),
68 p2i(slice));
69
70 objArrayOop objArray = objArrayOop(start_address);
71
72 size_t already_scanned = slice - start_address;
73 size_t remaining = objArray->size() - already_scanned;
74
75 return process_array_slice(objArray, slice, remaining);
76}
77