0
|
1 /*
|
|
2 * Copyright 2002 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
|
|
20 * CA 95054 USA or visit www.sun.com if you need additional information or
|
|
21 * have any questions.
|
|
22 *
|
|
23 */
|
|
24
|
|
25 //
|
|
26 // PSPromotionLAB is a parallel scavenge promotion lab. This class acts very
|
|
27 // much like a MutableSpace. We couldn't embed a MutableSpace, though, as
|
|
28 // it has a considerable number of asserts and invariants that are violated.
|
|
29 //
|
|
30
|
|
31 class ObjectStartArray;
|
|
32
|
|
33 class PSPromotionLAB : public CHeapObj {
|
|
34 protected:
|
|
35 static const size_t filler_header_size;
|
|
36
|
|
37 enum LabState {
|
|
38 needs_flush,
|
|
39 flushed,
|
|
40 zero_size
|
|
41 };
|
|
42
|
|
43 HeapWord* _top;
|
|
44 HeapWord* _bottom;
|
|
45 HeapWord* _end;
|
|
46 LabState _state;
|
|
47
|
|
48 void set_top(HeapWord* value) { _top = value; }
|
|
49 void set_bottom(HeapWord* value) { _bottom = value; }
|
|
50 void set_end(HeapWord* value) { _end = value; }
|
|
51
|
|
52 // The shared initialize code invokes this.
|
|
53 debug_only(virtual bool lab_is_valid(MemRegion lab) { return false; });
|
|
54
|
|
55 PSPromotionLAB() : _top(NULL), _bottom(NULL), _end(NULL) { }
|
|
56
|
|
57 public:
|
|
58 // Filling and flushing.
|
|
59 void initialize(MemRegion lab);
|
|
60
|
|
61 virtual void flush();
|
|
62
|
|
63 // Accessors
|
|
64 HeapWord* bottom() const { return _bottom; }
|
|
65 HeapWord* end() const { return _end; }
|
|
66 HeapWord* top() const { return _top; }
|
|
67
|
|
68 bool is_flushed() { return _state == flushed; }
|
|
69
|
|
70 bool unallocate_object(oop obj);
|
|
71
|
|
72 // Returns a subregion containing all objects in this space.
|
|
73 MemRegion used_region() { return MemRegion(bottom(), top()); }
|
|
74
|
|
75 // Boolean querries.
|
|
76 bool is_empty() const { return used() == 0; }
|
|
77 bool not_empty() const { return used() > 0; }
|
|
78 bool contains(const void* p) const { return _bottom <= p && p < _end; }
|
|
79
|
|
80 // Size computations. Sizes are in bytes.
|
|
81 size_t capacity() const { return byte_size(bottom(), end()); }
|
|
82 size_t used() const { return byte_size(bottom(), top()); }
|
|
83 size_t free() const { return byte_size(top(), end()); }
|
|
84 };
|
|
85
|
|
86 class PSYoungPromotionLAB : public PSPromotionLAB {
|
|
87 public:
|
|
88 PSYoungPromotionLAB() { }
|
|
89
|
|
90 // Not MT safe
|
|
91 HeapWord* allocate(size_t size) {
|
|
92 // Can't assert this, when young fills, we keep the LAB around, but flushed.
|
|
93 // assert(_state != flushed, "Sanity");
|
|
94 HeapWord* obj = top();
|
|
95 HeapWord* new_top = obj + size;
|
|
96 // The 'new_top>obj' check is needed to detect overflow of obj+size.
|
|
97 if (new_top > obj && new_top <= end()) {
|
|
98 set_top(new_top);
|
|
99 assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
|
|
100 "checking alignment");
|
|
101 return obj;
|
|
102 }
|
|
103
|
|
104 return NULL;
|
|
105 }
|
|
106
|
|
107 debug_only(virtual bool lab_is_valid(MemRegion lab));
|
|
108 };
|
|
109
|
|
110 class PSOldPromotionLAB : public PSPromotionLAB {
|
|
111 private:
|
|
112 ObjectStartArray* _start_array;
|
|
113
|
|
114 public:
|
|
115 PSOldPromotionLAB() : _start_array(NULL) { }
|
|
116 PSOldPromotionLAB(ObjectStartArray* start_array) : _start_array(start_array) { }
|
|
117
|
|
118 void set_start_array(ObjectStartArray* start_array) { _start_array = start_array; }
|
|
119
|
|
120 void flush();
|
|
121
|
|
122 // Not MT safe
|
|
123 HeapWord* allocate(size_t size) {
|
|
124 // Cannot test for this now that we're doing promotion failures
|
|
125 // assert(_state != flushed, "Sanity");
|
|
126 assert(_start_array != NULL, "Sanity");
|
|
127 HeapWord* obj = top();
|
|
128 HeapWord* new_top = obj + size;
|
|
129 // The 'new_top>obj' check is needed to detect overflow of obj+size.
|
|
130 if (new_top > obj && new_top <= end()) {
|
|
131 set_top(new_top);
|
|
132 assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
|
|
133 "checking alignment");
|
|
134 _start_array->allocate_block(obj);
|
|
135 return obj;
|
|
136 }
|
|
137
|
|
138 return NULL;
|
|
139 }
|
|
140
|
|
141 debug_only(virtual bool lab_is_valid(MemRegion lab));
|
|
142 };
|