1 /*
2 * Copyright (c) 2003, 2015, 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 *
42 // | |
43 // ========= <--- low_boundary for H, high_boundary for L
44 // | |
45 // | |
46 // | |
47 // --------- <--- high for L
48 // | |
49 // | L |
50 // | |
51 // | |
52 // | |
53 // +-------+ <--- low_boundary for L
54 //
55 // Each virtual space in the AdjoiningVirtualSpaces grows and shrink
56 // within its reserved region (between the low_boundary and the
57 // boundary) independently. If L want to grow above its high_boundary,
58 // then the high_boundary of L and the low_boundary of H must be
59 // moved up consistently. AdjoiningVirtualSpaces provide the
60 // interfaces for moving the this boundary.
61
62 class AdjoiningVirtualSpaces {
63 // space at the high end and the low end, respectively
64 PSVirtualSpace* _high;
65 PSVirtualSpace* _low;
66
67 // The reserved space spanned by the two spaces.
68 ReservedSpace _reserved_space;
69
70 // The minimum byte size for the low space. It will not
71 // be shrunk below this value.
72 size_t _min_low_byte_size;
73 // Same for the high space
74 size_t _min_high_byte_size;
75
76 const size_t _alignment;
77
78 public:
79 // Allocates two virtual spaces that will be located at the
80 // high and low ends. Does no initialization.
81 AdjoiningVirtualSpaces(ReservedSpace rs,
82 size_t min_low_byte_size,
83 size_t min_high_byte_size,
84 size_t alignment);
85
86 // accessors
87 PSVirtualSpace* high() { return _high; }
88 PSVirtualSpace* low() { return _low; }
89 ReservedSpace reserved_space() { return _reserved_space; }
90 size_t min_low_byte_size() { return _min_low_byte_size; }
91 size_t min_high_byte_size() { return _min_high_byte_size; }
92 size_t alignment() const { return _alignment; }
93
94 // move boundary between the two spaces up
95 bool adjust_boundary_up(size_t size_in_bytes);
96 // and down
97 bool adjust_boundary_down(size_t size_in_bytes);
98
99 // Maximum byte size for the high space.
100 size_t high_byte_size_limit() {
101 return _reserved_space.size() - _min_low_byte_size;
102 }
103 // Maximum byte size for the low space.
104 size_t low_byte_size_limit() {
105 return _reserved_space.size() - _min_high_byte_size;
106 }
107
108 // Sets the boundaries for the virtual spaces and commits and
109 // initial size;
110 void initialize(size_t max_low_byte_size,
111 size_t init_low_byte_size,
112 size_t init_high_byte_size);
113 };
114
115 #endif // SHARE_VM_GC_PARALLEL_ADJOININGVIRTUALSPACES_HPP
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1 /*
2 * Copyright (c) 2003, 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 *
42 // | |
43 // ========= <--- low_boundary for H, high_boundary for L
44 // | |
45 // | |
46 // | |
47 // --------- <--- high for L
48 // | |
49 // | L |
50 // | |
51 // | |
52 // | |
53 // +-------+ <--- low_boundary for L
54 //
55 // Each virtual space in the AdjoiningVirtualSpaces grows and shrink
56 // within its reserved region (between the low_boundary and the
57 // boundary) independently. If L want to grow above its high_boundary,
58 // then the high_boundary of L and the low_boundary of H must be
59 // moved up consistently. AdjoiningVirtualSpaces provide the
60 // interfaces for moving the this boundary.
61
62 class AdjoiningVirtualSpaces : public CHeapObj<mtGC> {
63 // space at the high end and the low end, respectively
64 PSVirtualSpace* _high;
65 PSVirtualSpace* _low;
66
67 protected:
68 // The reserved space spanned by the two spaces.
69 ReservedSpace _reserved_space;
70
71 // The minimum byte size for the low space. It will not
72 // be shrunk below this value.
73 size_t _min_low_byte_size;
74 // Same for the high space
75 size_t _min_high_byte_size;
76
77 const size_t _alignment;
78
79 public:
80 // Allocates two virtual spaces that will be located at the
81 // high and low ends. Does no initialization.
82 AdjoiningVirtualSpaces(ReservedSpace rs,
83 size_t min_low_byte_size,
84 size_t min_high_byte_size,
85 size_t alignment);
86
87 // accessors
88 virtual PSVirtualSpace* high() { return _high; }
89 virtual PSVirtualSpace* low() { return _low; }
90 ReservedSpace reserved_space() { return _reserved_space; }
91 size_t min_low_byte_size() { return _min_low_byte_size; }
92 size_t min_high_byte_size() { return _min_high_byte_size; }
93 size_t alignment() const { return _alignment; }
94
95 // move boundary between the two spaces up
96 virtual bool adjust_boundary_up(size_t size_in_bytes);
97 // and down
98 virtual bool adjust_boundary_down(size_t size_in_bytes);
99
100 // Maximum byte size for the high space.
101 size_t high_byte_size_limit() {
102 return _reserved_space.size() - _min_low_byte_size;
103 }
104 // Maximum byte size for the low space.
105 size_t low_byte_size_limit() {
106 return _reserved_space.size() - _min_high_byte_size;
107 }
108
109 // Sets the boundaries for the virtual spaces and commits and
110 // initial size;
111 void initialize(size_t max_low_byte_size,
112 size_t init_low_byte_size,
113 size_t init_high_byte_size);
114 };
115 #endif // SHARE_VM_GC_PARALLEL_ADJOININGVIRTUALSPACES_HPP
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