1 /*
  2  * Copyright (c) 2017, 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 #ifndef SHARE_GC_G1_G1FULLGCMARKER_INLINE_HPP
 26 #define SHARE_GC_G1_G1FULLGCMARKER_INLINE_HPP
 27 
 28 #include "gc/g1/g1Allocator.inline.hpp"
 29 #include "gc/g1/g1ConcurrentMarkBitMap.inline.hpp"
 30 #include "gc/g1/g1FullGCMarker.hpp"
 31 #include "gc/g1/g1FullGCOopClosures.inline.hpp"
 32 #include "gc/g1/g1StringDedup.hpp"
 33 #include "gc/g1/g1StringDedupQueue.hpp"
 34 #include "gc/shared/preservedMarks.inline.hpp"
 35 #include "oops/access.inline.hpp"
 36 #include "oops/compressedOops.inline.hpp"
 37 #include "oops/oop.inline.hpp"
 38 #include "utilities/debug.hpp"
 39 
 40 inline bool G1FullGCMarker::mark_object(oop obj) {
 41   // Not marking closed archive objects.
 42   if (G1ArchiveAllocator::is_closed_archive_object(obj)) {
 43     return false;
 44   }
 45 
 46   // Try to mark.
 47   if (!_bitmap->par_mark(obj)) {
 48     // Lost mark race.
 49     return false;
 50   }
 51 
 52   // Marked by us, preserve if needed.
 53   markWord mark = obj->mark();
 54   if (obj->mark_must_be_preserved(mark) &&
 55       !G1ArchiveAllocator::is_open_archive_object(obj)) {
 56     preserved_stack()->push(obj, mark);
 57   }
 58 
 59   // Check if deduplicatable string.
 60   if (G1StringDedup::is_enabled()) {
 61     G1StringDedup::enqueue_from_mark(obj, _worker_id);
 62   }
 63   return true;
 64 }
 65 
 66 template <class T> inline void G1FullGCMarker::mark_and_push(T* p) {
 67   T heap_oop = RawAccess<>::oop_load(p);
 68   if (!CompressedOops::is_null(heap_oop)) {
 69     oop obj = CompressedOops::decode_not_null(heap_oop);
 70     if (mark_object(obj)) {
 71       _oop_stack.push(obj);
 72       assert(_bitmap->is_marked(obj), "Must be marked now - map self");
 73     } else {
 74       assert(_bitmap->is_marked(obj) || G1ArchiveAllocator::is_closed_archive_object(obj),
 75              "Must be marked by other or closed archive object");
 76     }
 77   }
 78 }
 79 
 80 inline bool G1FullGCMarker::is_empty() {
 81   return _oop_stack.is_empty() && _objarray_stack.is_empty();
 82 }
 83 
 84 inline bool G1FullGCMarker::pop_object(oop& oop) {
 85   return _oop_stack.pop_overflow(oop) || _oop_stack.pop_local(oop);
 86 }
 87 
 88 inline void G1FullGCMarker::push_objarray(oop obj, size_t index) {
 89   ObjArrayTask task(obj, index);
 90   assert(task.is_valid(), "bad ObjArrayTask");
 91   _objarray_stack.push(task);
 92 }
 93 
 94 inline bool G1FullGCMarker::pop_objarray(ObjArrayTask& arr) {
 95   return _objarray_stack.pop_overflow(arr) || _objarray_stack.pop_local(arr);
 96 }
 97 
 98 inline void G1FullGCMarker::follow_array(objArrayOop array) {
 99   follow_klass(array->klass());
100   // Don't push empty arrays to avoid unnecessary work.
101   if (array->length() > 0) {
102     push_objarray(array, 0);
103   }
104 }
105 
106 void G1FullGCMarker::follow_array_chunk(objArrayOop array, int index) {
107   const int len = array->length();
108   const int beg_index = index;
109   assert(beg_index < len || len == 0, "index too large");
110 
111   const int stride = MIN2(len - beg_index, (int) ObjArrayMarkingStride);
112   const int end_index = beg_index + stride;
113 
114   // Push the continuation first to allow more efficient work stealing.
115   if (end_index < len) {
116     push_objarray(array, end_index);
117   }
118 
119   array->oop_iterate_range(mark_closure(), beg_index, end_index);
120 
121   if (VerifyDuringGC) {
122     _verify_closure.set_containing_obj(array);
123     array->oop_iterate_range(&_verify_closure, beg_index, end_index);
124     if (_verify_closure.failures()) {
125       assert(false, "Failed");
126     }
127   }
128 }
129 
130 inline void G1FullGCMarker::follow_object(oop obj) {
131   assert(_bitmap->is_marked(obj), "should be marked");
132   if (obj->is_objArray()) {
133     // Handle object arrays explicitly to allow them to
134     // be split into chunks if needed.
135     follow_array((objArrayOop)obj);
136   } else {
137     obj->oop_iterate(mark_closure());
138     if (VerifyDuringGC) {
139       if (obj->is_instance() && InstanceKlass::cast(obj->klass())->is_reference_instance_klass()) {
140         return;
141       }
142       _verify_closure.set_containing_obj(obj);
143       obj->oop_iterate(&_verify_closure);
144       if (_verify_closure.failures()) {
145         log_warning(gc, verify)("Failed after %d", _verify_closure._cc);
146         assert(false, "Failed");
147       }
148     }
149   }
150 }
151 
152 void G1FullGCMarker::drain_stack() {
153   do {
154     oop obj;
155     while (pop_object(obj)) {
156       assert(_bitmap->is_marked(obj), "must be marked");
157       follow_object(obj);
158     }
159     // Process ObjArrays one at a time to avoid marking stack bloat.
160     ObjArrayTask task;
161     if (pop_objarray(task)) {
162       follow_array_chunk(objArrayOop(task.obj()), task.index());
163     }
164   } while (!is_empty());
165 }
166 
167 inline void G1FullGCMarker::follow_klass(Klass* k) {
168   oop op = k->class_loader_data()->holder_no_keepalive();
169   mark_and_push(&op);
170 }
171 
172 inline void G1FullGCMarker::follow_cld(ClassLoaderData* cld) {
173   _cld_closure.do_cld(cld);
174 }
175 
176 #endif // SHARE_GC_G1_G1FULLGCMARKER_INLINE_HPP