1 /*
2 * Copyright (c) 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_VM_GC_PARALLEL_PSCLOSURE_INLINE_HPP
26 #define SHARE_VM_GC_PARALLEL_PSCLOSURE_INLINE_HPP
27
28 #include "gc/parallel/psPromotionManager.inline.hpp"
29 #include "gc/parallel/psScavenge.inline.hpp"
30 #include "memory/iterator.hpp"
31 #include "oops/access.inline.hpp"
32 #include "oops/oop.inline.hpp"
33 #include "utilities/globalDefinitions.hpp"
34
35 template<bool promote_immediately>
36 class PSRootsClosure: public OopClosure {
37 private:
38 PSPromotionManager* _promotion_manager;
39
40 protected:
41 template <class T> void do_oop_work(T *p) {
42 if (PSScavenge::should_scavenge(p)) {
43 // We never card mark roots, maybe call a func without test?
44 _promotion_manager->copy_and_push_safe_barrier<T, promote_immediately>(p);
45 }
46 }
47 public:
48 PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }
49 void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); }
50 void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }
51 };
52
53 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;
54 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;
55
56 // Scavenges a single oop in a ClassLoaderData.
57 class PSScavengeFromCLDClosure: public OopClosure {
58 private:
59 PSPromotionManager* _pm;
60 // Used to redirty a scanned cld if it has oops
61 // pointing to the young generation after being scanned.
62 ClassLoaderData* _scanned_cld;
63 public:
64 PSScavengeFromCLDClosure(PSPromotionManager* pm) : _pm(pm), _scanned_cld(NULL) { }
65 void do_oop(narrowOop* p) { ShouldNotReachHere(); }
66 void do_oop(oop* p) {
67 ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();
68 assert(!psh->is_in_reserved(p), "GC barrier needed");
69 if (PSScavenge::should_scavenge(p)) {
70 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
71
72 oop o = *p;
73 oop new_obj;
74 if (o->is_forwarded()) {
75 new_obj = o->forwardee();
76 } else {
77 new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o);
78 }
79 RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
80
81 if (PSScavenge::is_obj_in_young(new_obj)) {
82 do_cld_barrier();
83 }
84 }
85 }
86
87 void set_scanned_cld(ClassLoaderData* cld) {
88 assert(_scanned_cld == NULL || cld == NULL, "Should always only handling one cld at a time");
89 _scanned_cld = cld;
90 }
91
92 private:
93 void do_cld_barrier() {
94 assert(_scanned_cld != NULL, "Should not be called without having a scanned cld");
95 _scanned_cld->record_modified_oops();
96 }
97 };
98
99 // Scavenges the oop in a ClassLoaderData.
100 class PSScavengeCLDClosure: public CLDClosure {
101 private:
102 PSScavengeFromCLDClosure _oop_closure;
103 protected:
104 public:
105 PSScavengeCLDClosure(PSPromotionManager* pm) : _oop_closure(pm) { }
106 void do_cld(ClassLoaderData* cld) {
107 // If the cld has not been dirtied we know that there's
108 // no references into the young gen and we can skip it.
109
110 if (cld->has_modified_oops()) {
111 // Setup the promotion manager to redirty this cld
112 // if references are left in the young gen.
113 _oop_closure.set_scanned_cld(cld);
114
115 // Clean the cld since we're going to scavenge all the metadata.
116 cld->oops_do(&_oop_closure, false, /*clear_modified_oops*/true);
117
118 _oop_closure.set_scanned_cld(NULL);
119 }
120 }
121 };
122
123 #endif