Tue, 18 Jun 2013 12:31:07 -0700
8015237: Parallelize string table scanning during strong root processing
Summary: Parallelize the scanning of the intern string table by having each GC worker claim a given number of buckets. Changes were also reviewed by Per Liden <per.liden@oracle.com>.
Reviewed-by: tschatzl, stefank, twisti
1 /*
2 * Copyright (c) 1999, 2012, 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
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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.
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23 */
25 #include "precompiled.hpp"
26 #include "ci/ciKlass.hpp"
27 #include "ci/ciSymbol.hpp"
28 #include "ci/ciUtilities.hpp"
29 #include "oops/oop.inline.hpp"
31 // ciKlass
32 //
33 // This class represents a Klass* in the HotSpot virtual
34 // machine.
36 // ------------------------------------------------------------------
37 // ciKlass::ciKlass
38 ciKlass::ciKlass(KlassHandle h_k) : ciType(h_k) {
39 assert(get_Klass()->is_klass(), "wrong type");
40 Klass* k = get_Klass();
41 _layout_helper = k->layout_helper();
42 Symbol* klass_name = k->name();
43 assert(klass_name != NULL, "wrong ciKlass constructor");
44 _name = CURRENT_ENV->get_symbol(klass_name);
45 }
47 // ------------------------------------------------------------------
48 // ciKlass::ciKlass
49 //
50 // Nameless klass variant.
51 ciKlass::ciKlass(KlassHandle h_k, ciSymbol* name) : ciType(h_k) {
52 assert(get_Klass()->is_klass(), "wrong type");
53 _name = name;
54 _layout_helper = Klass::_lh_neutral_value;
55 }
57 // ------------------------------------------------------------------
58 // ciKlass::ciKlass
59 //
60 // Unloaded klass variant.
61 ciKlass::ciKlass(ciSymbol* name, BasicType bt) : ciType(bt) {
62 _name = name;
63 _layout_helper = Klass::_lh_neutral_value;
64 }
66 // ------------------------------------------------------------------
67 // ciKlass::is_subtype_of
68 bool ciKlass::is_subtype_of(ciKlass* that) {
69 assert(is_loaded() && that->is_loaded(), "must be loaded");
70 // Check to see if the klasses are identical.
71 if (this == that) {
72 return true;
73 }
75 VM_ENTRY_MARK;
76 Klass* this_klass = get_Klass();
77 Klass* that_klass = that->get_Klass();
78 bool result = this_klass->is_subtype_of(that_klass);
80 return result;
81 }
83 // ------------------------------------------------------------------
84 // ciKlass::is_subclass_of
85 bool ciKlass::is_subclass_of(ciKlass* that) {
86 assert(is_loaded() && that->is_loaded(), "must be loaded");
87 // Check to see if the klasses are identical.
89 VM_ENTRY_MARK;
90 Klass* this_klass = get_Klass();
91 Klass* that_klass = that->get_Klass();
92 bool result = this_klass->is_subclass_of(that_klass);
94 return result;
95 }
97 // ------------------------------------------------------------------
98 // ciKlass::super_depth
99 juint ciKlass::super_depth() {
100 assert(is_loaded(), "must be loaded");
102 VM_ENTRY_MARK;
103 Klass* this_klass = get_Klass();
104 return this_klass->super_depth();
105 }
107 // ------------------------------------------------------------------
108 // ciKlass::super_check_offset
109 juint ciKlass::super_check_offset() {
110 assert(is_loaded(), "must be loaded");
112 VM_ENTRY_MARK;
113 Klass* this_klass = get_Klass();
114 return this_klass->super_check_offset();
115 }
117 // ------------------------------------------------------------------
118 // ciKlass::super_of_depth
119 ciKlass* ciKlass::super_of_depth(juint i) {
120 assert(is_loaded(), "must be loaded");
122 VM_ENTRY_MARK;
123 Klass* this_klass = get_Klass();
124 Klass* super = this_klass->primary_super_of_depth(i);
125 return (super != NULL) ? CURRENT_THREAD_ENV->get_klass(super) : NULL;
126 }
128 // ------------------------------------------------------------------
129 // ciKlass::can_be_primary_super
130 bool ciKlass::can_be_primary_super() {
131 assert(is_loaded(), "must be loaded");
133 VM_ENTRY_MARK;
134 Klass* this_klass = get_Klass();
135 return this_klass->can_be_primary_super();
136 }
138 // ------------------------------------------------------------------
139 // ciKlass::least_common_ancestor
140 //
141 // Get the shared parent of two klasses.
142 //
143 // Implementation note: this method currently goes "over the wall"
144 // and does all of the work on the VM side. It could be rewritten
145 // to use the super() method and do all of the work (aside from the
146 // lazy computation of super()) in native mode. This may be
147 // worthwhile if the compiler is repeatedly requesting the same lca
148 // computation or possibly if most of the superklasses have already
149 // been created as ciObjects anyway. Something to think about...
150 ciKlass*
151 ciKlass::least_common_ancestor(ciKlass* that) {
152 assert(is_loaded() && that->is_loaded(), "must be loaded");
153 // Check to see if the klasses are identical.
154 if (this == that) {
155 return this;
156 }
158 VM_ENTRY_MARK;
159 Klass* this_klass = get_Klass();
160 Klass* that_klass = that->get_Klass();
161 Klass* lca = this_klass->LCA(that_klass);
163 // Many times the LCA will be either this_klass or that_klass.
164 // Treat these as special cases.
165 if (lca == that_klass) {
166 return that;
167 }
168 if (this_klass == lca) {
169 return this;
170 }
172 // Create the ciInstanceKlass for the lca.
173 ciKlass* result =
174 CURRENT_THREAD_ENV->get_klass(lca);
176 return result;
177 }
179 // ------------------------------------------------------------------
180 // ciKlass::find_klass
181 //
182 // Find a klass using this klass's class loader.
183 ciKlass* ciKlass::find_klass(ciSymbol* klass_name) {
184 assert(is_loaded(), "cannot find_klass through an unloaded klass");
185 return CURRENT_ENV->get_klass_by_name(this,
186 klass_name, false);
187 }
189 // ------------------------------------------------------------------
190 // ciKlass::java_mirror
191 //
192 // Get the instance of java.lang.Class corresponding to this klass.
193 // If it is an unloaded instance or array klass, return an unloaded
194 // mirror object of type Class.
195 ciInstance* ciKlass::java_mirror() {
196 GUARDED_VM_ENTRY(
197 if (!is_loaded())
198 return ciEnv::current()->get_unloaded_klass_mirror(this);
199 oop java_mirror = get_Klass()->java_mirror();
200 return CURRENT_ENV->get_instance(java_mirror);
201 )
202 }
204 // ------------------------------------------------------------------
205 // ciKlass::modifier_flags
206 jint ciKlass::modifier_flags() {
207 assert(is_loaded(), "not loaded");
208 GUARDED_VM_ENTRY(
209 return get_Klass()->modifier_flags();
210 )
211 }
213 // ------------------------------------------------------------------
214 // ciKlass::access_flags
215 jint ciKlass::access_flags() {
216 assert(is_loaded(), "not loaded");
217 GUARDED_VM_ENTRY(
218 return get_Klass()->access_flags().as_int();
219 )
220 }
222 // ------------------------------------------------------------------
223 // ciKlass::print_impl
224 //
225 // Implementation of the print method
226 void ciKlass::print_impl(outputStream* st) {
227 st->print(" name=");
228 print_name_on(st);
229 }
231 // ------------------------------------------------------------------
232 // ciKlass::print_name
233 //
234 // Print the name of this klass
235 void ciKlass::print_name_on(outputStream* st) {
236 name()->print_symbol_on(st);
237 }