1 /*
  2  * Copyright (c) 2000, 2019, 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_SERIAL_MARKSWEEP_INLINE_HPP
 26 #define SHARE_GC_SERIAL_MARKSWEEP_INLINE_HPP
 27 
 28 #include "gc/serial/markSweep.hpp"
 29 
 30 #include "gc/shared/slidingForwarding.inline.hpp"
 31 #include "classfile/classLoaderData.inline.hpp"
 32 #include "memory/universe.hpp"
 33 #include "oops/markWord.inline.hpp"
 34 #include "oops/access.inline.hpp"
 35 #include "oops/compressedOops.inline.hpp"
 36 #include "oops/oop.inline.hpp"
 37 #include "utilities/align.hpp"
 38 #include "utilities/stack.inline.hpp"
 39 
 40 inline void MarkSweep::mark_object(oop obj) {
 41   // some marks may contain information we need to preserve so we store them away
 42   // and overwrite the mark.  We'll restore it at the end of markSweep.
 43   markWord mark = obj->mark();
 44 #ifdef _LP64
 45   if (UseCompactObjectHeaders) {
 46     markWord real_mark = mark;
 47     if (real_mark.has_displaced_mark_helper()) {
 48       real_mark = real_mark.displaced_mark_helper();
 49     }
 50     Klass* klass = real_mark.klass();
 51     obj->set_mark(klass->prototype_header().set_marked());
 52   } else
 53 #endif
 54   {
 55     obj->set_mark(markWord::prototype().set_marked());
 56   }
 57 
 58   if (obj->mark_must_be_preserved(mark)) {
 59     preserve_mark(obj, mark);
 60   }
 61 }
 62 
 63 template <class T> inline void MarkSweep::mark_and_push(T* p) {
 64   T heap_oop = RawAccess<>::oop_load(p);
 65   if (!CompressedOops::is_null(heap_oop)) {
 66     oop obj = CompressedOops::decode_not_null(heap_oop);
 67     if (!obj->mark().is_marked()) {
 68       mark_object(obj);
 69       _marking_stack.push(obj);
 70     }
 71   }
 72 }
 73 
 74 inline void MarkSweep::follow_klass(Klass* klass) {
 75   oop op = klass->class_loader_data()->holder_no_keepalive();
 76   MarkSweep::mark_and_push(&op);
 77 }
 78 
 79 inline void MarkSweep::follow_cld(ClassLoaderData* cld) {
 80   MarkSweep::follow_cld_closure.do_cld(cld);
 81 }
 82 
 83 template <typename T>
 84 inline void MarkAndPushClosure::do_oop_work(T* p)            { MarkSweep::mark_and_push(p); }
 85 inline void MarkAndPushClosure::do_oop(oop* p)               { do_oop_work(p); }
 86 inline void MarkAndPushClosure::do_oop(narrowOop* p)         { do_oop_work(p); }
 87 inline void MarkAndPushClosure::do_klass(Klass* k)           { MarkSweep::follow_klass(k); }
 88 inline void MarkAndPushClosure::do_cld(ClassLoaderData* cld) { MarkSweep::follow_cld(cld); }
 89 
 90 template <class T> inline void MarkSweep::adjust_pointer(const SlidingForwarding* const forwarding, T* p) {
 91   T heap_oop = RawAccess<>::oop_load(p);
 92   if (!CompressedOops::is_null(heap_oop)) {
 93     oop obj = CompressedOops::decode_not_null(heap_oop);
 94     assert(Universe::heap()->is_in(obj), "should be in heap");
 95 
 96     markWord header = obj->mark();
 97     if (header.is_marked()) {
 98       oop new_obj = forwarding->forwardee(obj);
 99       assert(new_obj != NULL, "must be forwarded");
100       assert(is_object_aligned(new_obj), "oop must be aligned");
101       RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
102     }
103   }
104 }
105 
106 template <typename T>
107 void AdjustPointerClosure::do_oop_work(T* p)           { MarkSweep::adjust_pointer(_forwarding, p); }
108 inline void AdjustPointerClosure::do_oop(oop* p)       { do_oop_work(p); }
109 inline void AdjustPointerClosure::do_oop(narrowOop* p) { do_oop_work(p); }
110 
111 
112 inline int MarkSweep::adjust_pointers(const SlidingForwarding* const forwarding, oop obj) {
113   AdjustPointerClosure cl(forwarding);
114   return obj->oop_iterate_size(&cl);
115 }
116 
117 #endif // SHARE_GC_SERIAL_MARKSWEEP_INLINE_HPP