Mercurial > hg > graal-jvmci-8
annotate src/share/vm/classfile/placeholders.cpp @ 2129:8f8dfba37802
6994753: Implement optional hook to a Java method at VM startup.
Reviewed-by: mchung, acorn
author | kevinw |
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date | Wed, 12 Jan 2011 15:44:16 +0000 |
parents | f95d63e2154a |
children | 3582bf76420e |
rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. |
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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. | |
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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). | |
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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 * | |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 25 #include "precompiled.hpp" |
26 #include "classfile/placeholders.hpp" | |
27 #include "classfile/systemDictionary.hpp" | |
28 #include "oops/oop.inline.hpp" | |
29 #include "runtime/fieldType.hpp" | |
30 #include "utilities/hashtable.inline.hpp" | |
0 | 31 |
32 // Placeholder methods | |
33 | |
34 PlaceholderEntry* PlaceholderTable::new_entry(int hash, symbolOop name, | |
35 oop loader, bool havesupername, | |
36 symbolOop supername) { | |
37 PlaceholderEntry* entry = (PlaceholderEntry*)Hashtable::new_entry(hash, name); | |
38 entry->set_loader(loader); | |
39 entry->set_havesupername(havesupername); | |
40 entry->set_supername(supername); | |
41 entry->set_superThreadQ(NULL); | |
42 entry->set_loadInstanceThreadQ(NULL); | |
43 entry->set_defineThreadQ(NULL); | |
44 entry->set_definer(NULL); | |
45 entry->set_instanceKlass(NULL); | |
46 return entry; | |
47 } | |
48 | |
49 | |
50 // Placeholder objects represent classes currently being loaded. | |
51 // All threads examining the placeholder table must hold the | |
52 // SystemDictionary_lock, so we don't need special precautions | |
53 // on store ordering here. | |
54 void PlaceholderTable::add_entry(int index, unsigned int hash, | |
55 symbolHandle class_name, Handle class_loader, | |
56 bool havesupername, symbolHandle supername){ | |
57 assert_locked_or_safepoint(SystemDictionary_lock); | |
58 assert(!class_name.is_null(), "adding NULL obj"); | |
59 | |
60 // Both readers and writers are locked so it's safe to just | |
61 // create the placeholder and insert it in the list without a membar. | |
62 PlaceholderEntry* entry = new_entry(hash, class_name(), class_loader(), havesupername, supername()); | |
63 add_entry(index, entry); | |
64 } | |
65 | |
66 | |
67 // Remove a placeholder object. | |
68 void PlaceholderTable::remove_entry(int index, unsigned int hash, | |
69 symbolHandle class_name, | |
70 Handle class_loader) { | |
71 assert_locked_or_safepoint(SystemDictionary_lock); | |
72 PlaceholderEntry** p = bucket_addr(index); | |
73 while (*p) { | |
74 PlaceholderEntry *probe = *p; | |
75 if (probe->hash() == hash && probe->equals(class_name(), class_loader())) { | |
76 // Delete entry | |
77 *p = probe->next(); | |
78 free_entry(probe); | |
79 return; | |
80 } | |
81 p = probe->next_addr(); | |
82 } | |
83 } | |
84 | |
85 PlaceholderEntry* PlaceholderTable::get_entry(int index, unsigned int hash, | |
86 symbolHandle class_name, | |
87 Handle class_loader) { | |
88 assert_locked_or_safepoint(SystemDictionary_lock); | |
89 | |
90 symbolOop class_name_ = class_name(); | |
91 oop class_loader_ = class_loader(); | |
92 | |
93 for (PlaceholderEntry *place_probe = bucket(index); | |
94 place_probe != NULL; | |
95 place_probe = place_probe->next()) { | |
96 if (place_probe->hash() == hash && | |
97 place_probe->equals(class_name_, class_loader_)) { | |
98 return place_probe; | |
99 } | |
100 } | |
101 return NULL; | |
102 } | |
103 | |
104 symbolOop PlaceholderTable::find_entry(int index, unsigned int hash, | |
105 symbolHandle class_name, | |
106 Handle class_loader) { | |
107 PlaceholderEntry* probe = get_entry(index, hash, class_name, class_loader); | |
108 return (probe? probe->klass(): symbolOop(NULL)); | |
109 } | |
110 | |
111 // find_and_add returns probe pointer - old or new | |
112 // If no entry exists, add a placeholder entry | |
113 // If entry exists, reuse entry | |
114 // For both, push SeenThread for classloadAction | |
115 // if havesupername: this is used for circularity for instanceklass loading | |
116 PlaceholderEntry* PlaceholderTable::find_and_add(int index, unsigned int hash, symbolHandle name, Handle loader, classloadAction action, symbolHandle supername, Thread* thread) { | |
117 PlaceholderEntry* probe = get_entry(index, hash, name, loader); | |
118 if (probe == NULL) { | |
119 // Nothing found, add place holder | |
120 add_entry(index, hash, name, loader, (action == LOAD_SUPER), supername); | |
121 probe = get_entry(index, hash, name, loader); | |
122 } else { | |
123 if (action == LOAD_SUPER) { | |
124 probe->set_havesupername(true); | |
125 probe->set_supername(supername()); | |
126 } | |
127 } | |
128 if (probe) probe->add_seen_thread(thread, action); | |
129 return probe; | |
130 } | |
131 | |
132 | |
133 // placeholder used to track class loading internal states | |
134 // placeholder existence now for loading superclass/superinterface | |
135 // superthreadQ tracks class circularity, while loading superclass/superinterface | |
136 // loadInstanceThreadQ tracks load_instance_class calls | |
137 // definer() tracks the single thread that owns define token | |
138 // defineThreadQ tracks waiters on defining thread's results | |
139 // 1st claimant creates placeholder | |
140 // find_and_add adds SeenThread entry for appropriate queue | |
141 // All claimants remove SeenThread after completing action | |
142 // On removal: if definer and all queues empty, remove entry | |
143 // Note: you can be in both placeholders and systemDictionary | |
144 // see parse_stream for redefine classes | |
145 // Therefore - must always check SD first | |
146 // Ignores the case where entry is not found | |
147 void PlaceholderTable::find_and_remove(int index, unsigned int hash, | |
148 symbolHandle name, Handle loader, Thread* thread) { | |
149 assert_locked_or_safepoint(SystemDictionary_lock); | |
150 PlaceholderEntry *probe = get_entry(index, hash, name, loader); | |
151 if (probe != NULL) { | |
152 // No other threads using this entry | |
153 if ((probe->superThreadQ() == NULL) && (probe->loadInstanceThreadQ() == NULL) | |
154 && (probe->defineThreadQ() == NULL) && (probe->definer() == NULL)) { | |
155 remove_entry(index, hash, name, loader); | |
156 } | |
157 } | |
158 } | |
159 | |
160 PlaceholderTable::PlaceholderTable(int table_size) | |
161 : TwoOopHashtable(table_size, sizeof(PlaceholderEntry)) { | |
162 } | |
163 | |
164 | |
165 void PlaceholderTable::oops_do(OopClosure* f) { | |
166 for (int index = 0; index < table_size(); index++) { | |
167 for (PlaceholderEntry* probe = bucket(index); | |
168 probe != NULL; | |
169 probe = probe->next()) { | |
170 probe->oops_do(f); | |
171 } | |
172 } | |
173 } | |
174 | |
175 | |
176 void PlaceholderEntry::oops_do(OopClosure* blk) { | |
177 assert(klass() != NULL, "should have a non-null klass"); | |
178 blk->do_oop((oop*)klass_addr()); | |
179 if (_loader != NULL) { | |
180 blk->do_oop(loader_addr()); | |
181 } | |
182 if (_supername != NULL) { | |
183 blk->do_oop((oop*)supername_addr()); | |
184 } | |
185 if (_instanceKlass != NULL) { | |
186 blk->do_oop((oop*)instanceKlass_addr()); | |
187 } | |
188 } | |
189 | |
190 // do all entries in the placeholder table | |
191 void PlaceholderTable::entries_do(void f(symbolOop, oop)) { | |
192 for (int index = 0; index < table_size(); index++) { | |
193 for (PlaceholderEntry* probe = bucket(index); | |
194 probe != NULL; | |
195 probe = probe->next()) { | |
196 f(probe->klass(), probe->loader()); | |
197 } | |
198 } | |
199 } | |
200 | |
201 | |
202 #ifndef PRODUCT | |
203 // Note, doesn't append a cr | |
204 void PlaceholderEntry::print() const { | |
205 klass()->print_value(); | |
206 if (loader() != NULL) { | |
207 tty->print(", loader "); | |
208 loader()->print_value(); | |
209 } | |
210 if (supername() != NULL) { | |
211 tty->print(", supername "); | |
212 supername()->print_value(); | |
213 } | |
214 if (definer() != NULL) { | |
215 tty->print(", definer "); | |
216 definer()->print_value(); | |
217 } | |
218 if (instanceKlass() != NULL) { | |
219 tty->print(", instanceKlass "); | |
220 instanceKlass()->print_value(); | |
221 } | |
222 tty->print("\n"); | |
223 tty->print("loadInstanceThreadQ threads:"); | |
224 loadInstanceThreadQ()->printActionQ(); | |
225 tty->print("\n"); | |
226 tty->print("superThreadQ threads:"); | |
227 superThreadQ()->printActionQ(); | |
228 tty->print("\n"); | |
229 tty->print("defineThreadQ threads:"); | |
230 defineThreadQ()->printActionQ(); | |
231 tty->print("\n"); | |
232 } | |
233 #endif | |
234 | |
235 void PlaceholderEntry::verify() const { | |
236 guarantee(loader() == NULL || loader()->is_instance(), | |
237 "checking type of _loader"); | |
238 guarantee(instanceKlass() == NULL | |
239 || Klass::cast(instanceKlass())->oop_is_instance(), | |
240 "checking type of instanceKlass result"); | |
241 klass()->verify(); | |
242 } | |
243 | |
244 void PlaceholderTable::verify() { | |
245 int element_count = 0; | |
246 for (int pindex = 0; pindex < table_size(); pindex++) { | |
247 for (PlaceholderEntry* probe = bucket(pindex); | |
248 probe != NULL; | |
249 probe = probe->next()) { | |
250 probe->verify(); | |
251 element_count++; // both klasses and place holders count | |
252 } | |
253 } | |
254 guarantee(number_of_entries() == element_count, | |
255 "Verify of system dictionary failed"); | |
256 } | |
257 | |
258 | |
259 #ifndef PRODUCT | |
260 void PlaceholderTable::print() { | |
261 for (int pindex = 0; pindex < table_size(); pindex++) { | |
262 for (PlaceholderEntry* probe = bucket(pindex); | |
263 probe != NULL; | |
264 probe = probe->next()) { | |
265 if (Verbose) tty->print("%4d: ", pindex); | |
266 tty->print(" place holder "); | |
267 | |
268 probe->print(); | |
269 tty->cr(); | |
270 } | |
271 } | |
272 } | |
273 #endif |