Thu, 21 Aug 2014 16:44:41 +0200
8055098: WB API should be extended to provide information about size and age of object.
Summary: Extend the WhiteBox API to provide information about the size and age of objects. Further add a mechanism to trigger a young GC.
Reviewed-by: tschatzl, sjohanss
Contributed-by: Leonid Mesnik <leonid.mesnik@oracle.com>
1 /*
2 * Copyright (c) 2014, 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.
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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
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23 */
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/g1PageBasedVirtualSpace.hpp"
27 #include "oops/markOop.hpp"
28 #include "oops/oop.inline.hpp"
29 #include "services/memTracker.hpp"
30 #ifdef TARGET_OS_FAMILY_linux
31 # include "os_linux.inline.hpp"
32 #endif
33 #ifdef TARGET_OS_FAMILY_solaris
34 # include "os_solaris.inline.hpp"
35 #endif
36 #ifdef TARGET_OS_FAMILY_windows
37 # include "os_windows.inline.hpp"
38 #endif
39 #ifdef TARGET_OS_FAMILY_aix
40 # include "os_aix.inline.hpp"
41 #endif
42 #ifdef TARGET_OS_FAMILY_bsd
43 # include "os_bsd.inline.hpp"
44 #endif
45 #include "utilities/bitMap.inline.hpp"
47 G1PageBasedVirtualSpace::G1PageBasedVirtualSpace() : _low_boundary(NULL),
48 _high_boundary(NULL), _committed(), _page_size(0), _special(false), _executable(false) {
49 }
51 bool G1PageBasedVirtualSpace::initialize_with_granularity(ReservedSpace rs, size_t page_size) {
52 if (!rs.is_reserved()) {
53 return false; // Allocation failed.
54 }
55 assert(_low_boundary == NULL, "VirtualSpace already initialized");
56 assert(page_size > 0, "Granularity must be non-zero.");
58 _low_boundary = rs.base();
59 _high_boundary = _low_boundary + rs.size();
61 _special = rs.special();
62 _executable = rs.executable();
64 _page_size = page_size;
66 assert(_committed.size() == 0, "virtual space initialized more than once");
67 uintx size_in_bits = rs.size() / page_size;
68 _committed.resize(size_in_bits, /* in_resource_area */ false);
70 return true;
71 }
74 G1PageBasedVirtualSpace::~G1PageBasedVirtualSpace() {
75 release();
76 }
78 void G1PageBasedVirtualSpace::release() {
79 // This does not release memory it never reserved.
80 // Caller must release via rs.release();
81 _low_boundary = NULL;
82 _high_boundary = NULL;
83 _special = false;
84 _executable = false;
85 _page_size = 0;
86 _committed.resize(0, false);
87 }
89 size_t G1PageBasedVirtualSpace::committed_size() const {
90 return _committed.count_one_bits() * _page_size;
91 }
93 size_t G1PageBasedVirtualSpace::reserved_size() const {
94 return pointer_delta(_high_boundary, _low_boundary, sizeof(char));
95 }
97 size_t G1PageBasedVirtualSpace::uncommitted_size() const {
98 return reserved_size() - committed_size();
99 }
101 uintptr_t G1PageBasedVirtualSpace::addr_to_page_index(char* addr) const {
102 return (addr - _low_boundary) / _page_size;
103 }
105 bool G1PageBasedVirtualSpace::is_area_committed(uintptr_t start, size_t size_in_pages) const {
106 uintptr_t end = start + size_in_pages;
107 return _committed.get_next_zero_offset(start, end) >= end;
108 }
110 bool G1PageBasedVirtualSpace::is_area_uncommitted(uintptr_t start, size_t size_in_pages) const {
111 uintptr_t end = start + size_in_pages;
112 return _committed.get_next_one_offset(start, end) >= end;
113 }
115 char* G1PageBasedVirtualSpace::page_start(uintptr_t index) {
116 return _low_boundary + index * _page_size;
117 }
119 size_t G1PageBasedVirtualSpace::byte_size_for_pages(size_t num) {
120 return num * _page_size;
121 }
123 MemRegion G1PageBasedVirtualSpace::commit(uintptr_t start, size_t size_in_pages) {
124 // We need to make sure to commit all pages covered by the given area.
125 guarantee(is_area_uncommitted(start, size_in_pages), "Specified area is not uncommitted");
127 if (!_special) {
128 os::commit_memory_or_exit(page_start(start), byte_size_for_pages(size_in_pages), _executable,
129 err_msg("Failed to commit pages from "SIZE_FORMAT" of length "SIZE_FORMAT, start, size_in_pages));
130 }
131 _committed.set_range(start, start + size_in_pages);
133 MemRegion result((HeapWord*)page_start(start), byte_size_for_pages(size_in_pages) / HeapWordSize);
134 return result;
135 }
137 MemRegion G1PageBasedVirtualSpace::uncommit(uintptr_t start, size_t size_in_pages) {
138 guarantee(is_area_committed(start, size_in_pages), "checking");
140 if (!_special) {
141 os::uncommit_memory(page_start(start), byte_size_for_pages(size_in_pages));
142 }
144 _committed.clear_range(start, start + size_in_pages);
146 MemRegion result((HeapWord*)page_start(start), byte_size_for_pages(size_in_pages) / HeapWordSize);
147 return result;
148 }
150 bool G1PageBasedVirtualSpace::contains(const void* p) const {
151 return _low_boundary <= (const char*) p && (const char*) p < _high_boundary;
152 }
154 #ifndef PRODUCT
155 void G1PageBasedVirtualSpace::print_on(outputStream* out) {
156 out->print ("Virtual space:");
157 if (special()) out->print(" (pinned in memory)");
158 out->cr();
159 out->print_cr(" - committed: " SIZE_FORMAT, committed_size());
160 out->print_cr(" - reserved: " SIZE_FORMAT, reserved_size());
161 out->print_cr(" - [low_b, high_b]: [" INTPTR_FORMAT ", " INTPTR_FORMAT "]", p2i(_low_boundary), p2i(_high_boundary));
162 }
164 void G1PageBasedVirtualSpace::print() {
165 print_on(tty);
166 }
167 #endif