Mercurial > hg > truffle
comparison src/share/vm/code/dependencies.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 65a06b4a51b8 d4a0f561287a |
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1 /* | |
2 * Copyright 2005-2007 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 # include "incls/_precompiled.incl" | |
26 # include "incls/_dependencies.cpp.incl" | |
27 | |
28 | |
29 #ifdef ASSERT | |
30 static bool must_be_in_vm() { | |
31 Thread* thread = Thread::current(); | |
32 if (thread->is_Java_thread()) | |
33 return ((JavaThread*)thread)->thread_state() == _thread_in_vm; | |
34 else | |
35 return true; //something like this: thread->is_VM_thread(); | |
36 } | |
37 #endif //ASSERT | |
38 | |
39 void Dependencies::initialize(ciEnv* env) { | |
40 Arena* arena = env->arena(); | |
41 _oop_recorder = env->oop_recorder(); | |
42 _log = env->log(); | |
43 _dep_seen = new(arena) GrowableArray<int>(arena, 500, 0, 0); | |
44 DEBUG_ONLY(_deps[end_marker] = NULL); | |
45 for (int i = (int)FIRST_TYPE; i < (int)TYPE_LIMIT; i++) { | |
46 _deps[i] = new(arena) GrowableArray<ciObject*>(arena, 10, 0, 0); | |
47 } | |
48 _content_bytes = NULL; | |
49 _size_in_bytes = (size_t)-1; | |
50 | |
51 assert(TYPE_LIMIT <= (1<<LG2_TYPE_LIMIT), "sanity"); | |
52 } | |
53 | |
54 void Dependencies::assert_evol_method(ciMethod* m) { | |
55 assert_common_1(evol_method, m); | |
56 } | |
57 | |
58 void Dependencies::assert_leaf_type(ciKlass* ctxk) { | |
59 if (ctxk->is_array_klass()) { | |
60 // As a special case, support this assertion on an array type, | |
61 // which reduces to an assertion on its element type. | |
62 // Note that this cannot be done with assertions that | |
63 // relate to concreteness or abstractness. | |
64 ciType* elemt = ctxk->as_array_klass()->base_element_type(); | |
65 if (!elemt->is_instance_klass()) return; // Ex: int[][] | |
66 ctxk = elemt->as_instance_klass(); | |
67 //if (ctxk->is_final()) return; // Ex: String[][] | |
68 } | |
69 check_ctxk(ctxk); | |
70 assert_common_1(leaf_type, ctxk); | |
71 } | |
72 | |
73 void Dependencies::assert_abstract_with_unique_concrete_subtype(ciKlass* ctxk, ciKlass* conck) { | |
74 check_ctxk_abstract(ctxk); | |
75 assert_common_2(abstract_with_unique_concrete_subtype, ctxk, conck); | |
76 } | |
77 | |
78 void Dependencies::assert_abstract_with_no_concrete_subtype(ciKlass* ctxk) { | |
79 check_ctxk_abstract(ctxk); | |
80 assert_common_1(abstract_with_no_concrete_subtype, ctxk); | |
81 } | |
82 | |
83 void Dependencies::assert_concrete_with_no_concrete_subtype(ciKlass* ctxk) { | |
84 check_ctxk_concrete(ctxk); | |
85 assert_common_1(concrete_with_no_concrete_subtype, ctxk); | |
86 } | |
87 | |
88 void Dependencies::assert_unique_concrete_method(ciKlass* ctxk, ciMethod* uniqm) { | |
89 check_ctxk(ctxk); | |
90 assert_common_2(unique_concrete_method, ctxk, uniqm); | |
91 } | |
92 | |
93 void Dependencies::assert_abstract_with_exclusive_concrete_subtypes(ciKlass* ctxk, ciKlass* k1, ciKlass* k2) { | |
94 check_ctxk(ctxk); | |
95 assert_common_3(abstract_with_exclusive_concrete_subtypes_2, ctxk, k1, k2); | |
96 } | |
97 | |
98 void Dependencies::assert_exclusive_concrete_methods(ciKlass* ctxk, ciMethod* m1, ciMethod* m2) { | |
99 check_ctxk(ctxk); | |
100 assert_common_3(exclusive_concrete_methods_2, ctxk, m1, m2); | |
101 } | |
102 | |
103 void Dependencies::assert_has_no_finalizable_subclasses(ciKlass* ctxk) { | |
104 check_ctxk(ctxk); | |
105 assert_common_1(no_finalizable_subclasses, ctxk); | |
106 } | |
107 | |
108 // Helper function. If we are adding a new dep. under ctxk2, | |
109 // try to find an old dep. under a broader* ctxk1. If there is | |
110 // | |
111 bool Dependencies::maybe_merge_ctxk(GrowableArray<ciObject*>* deps, | |
112 int ctxk_i, ciKlass* ctxk2) { | |
113 ciKlass* ctxk1 = deps->at(ctxk_i)->as_klass(); | |
114 if (ctxk2->is_subtype_of(ctxk1)) { | |
115 return true; // success, and no need to change | |
116 } else if (ctxk1->is_subtype_of(ctxk2)) { | |
117 // new context class fully subsumes previous one | |
118 deps->at_put(ctxk_i, ctxk2); | |
119 return true; | |
120 } else { | |
121 return false; | |
122 } | |
123 } | |
124 | |
125 void Dependencies::assert_common_1(Dependencies::DepType dept, ciObject* x) { | |
126 assert(dep_args(dept) == 1, "sanity"); | |
127 log_dependency(dept, x); | |
128 GrowableArray<ciObject*>* deps = _deps[dept]; | |
129 | |
130 // see if the same (or a similar) dep is already recorded | |
131 if (note_dep_seen(dept, x)) { | |
132 assert(deps->find(x) >= 0, "sanity"); | |
133 } else { | |
134 deps->append(x); | |
135 } | |
136 } | |
137 | |
138 void Dependencies::assert_common_2(Dependencies::DepType dept, | |
139 ciKlass* ctxk, ciObject* x) { | |
140 assert(dep_context_arg(dept) == 0, "sanity"); | |
141 assert(dep_args(dept) == 2, "sanity"); | |
142 log_dependency(dept, ctxk, x); | |
143 GrowableArray<ciObject*>* deps = _deps[dept]; | |
144 | |
145 // see if the same (or a similar) dep is already recorded | |
146 if (note_dep_seen(dept, x)) { | |
147 // look in this bucket for redundant assertions | |
148 const int stride = 2; | |
149 for (int i = deps->length(); (i -= stride) >= 0; ) { | |
150 ciObject* x1 = deps->at(i+1); | |
151 if (x == x1) { // same subject; check the context | |
152 if (maybe_merge_ctxk(deps, i+0, ctxk)) { | |
153 return; | |
154 } | |
155 } | |
156 } | |
157 } | |
158 | |
159 // append the assertion in the correct bucket: | |
160 deps->append(ctxk); | |
161 deps->append(x); | |
162 } | |
163 | |
164 void Dependencies::assert_common_3(Dependencies::DepType dept, | |
165 ciKlass* ctxk, ciObject* x, ciObject* x2) { | |
166 assert(dep_context_arg(dept) == 0, "sanity"); | |
167 assert(dep_args(dept) == 3, "sanity"); | |
168 log_dependency(dept, ctxk, x, x2); | |
169 GrowableArray<ciObject*>* deps = _deps[dept]; | |
170 | |
171 // try to normalize an unordered pair: | |
172 bool swap = false; | |
173 switch (dept) { | |
174 case abstract_with_exclusive_concrete_subtypes_2: | |
175 swap = (x->ident() > x2->ident() && x != ctxk); | |
176 break; | |
177 case exclusive_concrete_methods_2: | |
178 swap = (x->ident() > x2->ident() && x->as_method()->holder() != ctxk); | |
179 break; | |
180 } | |
181 if (swap) { ciObject* t = x; x = x2; x2 = t; } | |
182 | |
183 // see if the same (or a similar) dep is already recorded | |
184 if (note_dep_seen(dept, x) && note_dep_seen(dept, x2)) { | |
185 // look in this bucket for redundant assertions | |
186 const int stride = 3; | |
187 for (int i = deps->length(); (i -= stride) >= 0; ) { | |
188 ciObject* y = deps->at(i+1); | |
189 ciObject* y2 = deps->at(i+2); | |
190 if (x == y && x2 == y2) { // same subjects; check the context | |
191 if (maybe_merge_ctxk(deps, i+0, ctxk)) { | |
192 return; | |
193 } | |
194 } | |
195 } | |
196 } | |
197 // append the assertion in the correct bucket: | |
198 deps->append(ctxk); | |
199 deps->append(x); | |
200 deps->append(x2); | |
201 } | |
202 | |
203 /// Support for encoding dependencies into an nmethod: | |
204 | |
205 void Dependencies::copy_to(nmethod* nm) { | |
206 address beg = nm->dependencies_begin(); | |
207 address end = nm->dependencies_end(); | |
208 guarantee(end - beg >= (ptrdiff_t) size_in_bytes(), "bad sizing"); | |
209 Copy::disjoint_words((HeapWord*) content_bytes(), | |
210 (HeapWord*) beg, | |
211 size_in_bytes() / sizeof(HeapWord)); | |
212 assert(size_in_bytes() % sizeof(HeapWord) == 0, "copy by words"); | |
213 } | |
214 | |
215 static int sort_dep(ciObject** p1, ciObject** p2, int narg) { | |
216 for (int i = 0; i < narg; i++) { | |
217 int diff = p1[i]->ident() - p2[i]->ident(); | |
218 if (diff != 0) return diff; | |
219 } | |
220 return 0; | |
221 } | |
222 static int sort_dep_arg_1(ciObject** p1, ciObject** p2) | |
223 { return sort_dep(p1, p2, 1); } | |
224 static int sort_dep_arg_2(ciObject** p1, ciObject** p2) | |
225 { return sort_dep(p1, p2, 2); } | |
226 static int sort_dep_arg_3(ciObject** p1, ciObject** p2) | |
227 { return sort_dep(p1, p2, 3); } | |
228 | |
229 void Dependencies::sort_all_deps() { | |
230 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) { | |
231 DepType dept = (DepType)deptv; | |
232 GrowableArray<ciObject*>* deps = _deps[dept]; | |
233 if (deps->length() <= 1) continue; | |
234 switch (dep_args(dept)) { | |
235 case 1: deps->sort(sort_dep_arg_1, 1); break; | |
236 case 2: deps->sort(sort_dep_arg_2, 2); break; | |
237 case 3: deps->sort(sort_dep_arg_3, 3); break; | |
238 default: ShouldNotReachHere(); | |
239 } | |
240 } | |
241 } | |
242 | |
243 size_t Dependencies::estimate_size_in_bytes() { | |
244 size_t est_size = 100; | |
245 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) { | |
246 DepType dept = (DepType)deptv; | |
247 GrowableArray<ciObject*>* deps = _deps[dept]; | |
248 est_size += deps->length()*2; // tags and argument(s) | |
249 } | |
250 return est_size; | |
251 } | |
252 | |
253 ciKlass* Dependencies::ctxk_encoded_as_null(DepType dept, ciObject* x) { | |
254 switch (dept) { | |
255 case abstract_with_exclusive_concrete_subtypes_2: | |
256 return x->as_klass(); | |
257 case unique_concrete_method: | |
258 case exclusive_concrete_methods_2: | |
259 return x->as_method()->holder(); | |
260 } | |
261 return NULL; // let NULL be NULL | |
262 } | |
263 | |
264 klassOop Dependencies::ctxk_encoded_as_null(DepType dept, oop x) { | |
265 assert(must_be_in_vm(), "raw oops here"); | |
266 switch (dept) { | |
267 case abstract_with_exclusive_concrete_subtypes_2: | |
268 assert(x->is_klass(), "sanity"); | |
269 return (klassOop) x; | |
270 case unique_concrete_method: | |
271 case exclusive_concrete_methods_2: | |
272 assert(x->is_method(), "sanity"); | |
273 return ((methodOop)x)->method_holder(); | |
274 } | |
275 return NULL; // let NULL be NULL | |
276 } | |
277 | |
278 void Dependencies::encode_content_bytes() { | |
279 sort_all_deps(); | |
280 | |
281 // cast is safe, no deps can overflow INT_MAX | |
282 CompressedWriteStream bytes((int)estimate_size_in_bytes()); | |
283 | |
284 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) { | |
285 DepType dept = (DepType)deptv; | |
286 GrowableArray<ciObject*>* deps = _deps[dept]; | |
287 if (deps->length() == 0) continue; | |
288 int stride = dep_args(dept); | |
289 int ctxkj = dep_context_arg(dept); // -1 if no context arg | |
290 assert(stride > 0, "sanity"); | |
291 for (int i = 0; i < deps->length(); i += stride) { | |
292 jbyte code_byte = (jbyte)dept; | |
293 int skipj = -1; | |
294 if (ctxkj >= 0 && ctxkj+1 < stride) { | |
295 ciKlass* ctxk = deps->at(i+ctxkj+0)->as_klass(); | |
296 ciObject* x = deps->at(i+ctxkj+1); // following argument | |
297 if (ctxk == ctxk_encoded_as_null(dept, x)) { | |
298 skipj = ctxkj; // we win: maybe one less oop to keep track of | |
299 code_byte |= default_context_type_bit; | |
300 } | |
301 } | |
302 bytes.write_byte(code_byte); | |
303 for (int j = 0; j < stride; j++) { | |
304 if (j == skipj) continue; | |
305 bytes.write_int(_oop_recorder->find_index(deps->at(i+j)->encoding())); | |
306 } | |
307 } | |
308 } | |
309 | |
310 // write a sentinel byte to mark the end | |
311 bytes.write_byte(end_marker); | |
312 | |
313 // round it out to a word boundary | |
314 while (bytes.position() % sizeof(HeapWord) != 0) { | |
315 bytes.write_byte(end_marker); | |
316 } | |
317 | |
318 // check whether the dept byte encoding really works | |
319 assert((jbyte)default_context_type_bit != 0, "byte overflow"); | |
320 | |
321 _content_bytes = bytes.buffer(); | |
322 _size_in_bytes = bytes.position(); | |
323 } | |
324 | |
325 | |
326 const char* Dependencies::_dep_name[TYPE_LIMIT] = { | |
327 "end_marker", | |
328 "evol_method", | |
329 "leaf_type", | |
330 "abstract_with_unique_concrete_subtype", | |
331 "abstract_with_no_concrete_subtype", | |
332 "concrete_with_no_concrete_subtype", | |
333 "unique_concrete_method", | |
334 "abstract_with_exclusive_concrete_subtypes_2", | |
335 "exclusive_concrete_methods_2", | |
336 "no_finalizable_subclasses" | |
337 }; | |
338 | |
339 int Dependencies::_dep_args[TYPE_LIMIT] = { | |
340 -1,// end_marker | |
341 1, // evol_method m | |
342 1, // leaf_type ctxk | |
343 2, // abstract_with_unique_concrete_subtype ctxk, k | |
344 1, // abstract_with_no_concrete_subtype ctxk | |
345 1, // concrete_with_no_concrete_subtype ctxk | |
346 2, // unique_concrete_method ctxk, m | |
347 3, // unique_concrete_subtypes_2 ctxk, k1, k2 | |
348 3, // unique_concrete_methods_2 ctxk, m1, m2 | |
349 1 // no_finalizable_subclasses ctxk | |
350 }; | |
351 | |
352 const char* Dependencies::dep_name(Dependencies::DepType dept) { | |
353 if (!dept_in_mask(dept, all_types)) return "?bad-dep?"; | |
354 return _dep_name[dept]; | |
355 } | |
356 | |
357 int Dependencies::dep_args(Dependencies::DepType dept) { | |
358 if (!dept_in_mask(dept, all_types)) return -1; | |
359 return _dep_args[dept]; | |
360 } | |
361 | |
362 // for the sake of the compiler log, print out current dependencies: | |
363 void Dependencies::log_all_dependencies() { | |
364 if (log() == NULL) return; | |
365 ciObject* args[max_arg_count]; | |
366 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) { | |
367 DepType dept = (DepType)deptv; | |
368 GrowableArray<ciObject*>* deps = _deps[dept]; | |
369 if (deps->length() == 0) continue; | |
370 int stride = dep_args(dept); | |
371 for (int i = 0; i < deps->length(); i += stride) { | |
372 for (int j = 0; j < stride; j++) { | |
373 // flush out the identities before printing | |
374 args[j] = deps->at(i+j); | |
375 } | |
376 write_dependency_to(log(), dept, stride, args); | |
377 } | |
378 } | |
379 } | |
380 | |
381 void Dependencies::write_dependency_to(CompileLog* log, | |
382 DepType dept, | |
383 int nargs, oop args[], | |
384 klassOop witness) { | |
385 if (log == NULL) { | |
386 return; | |
387 } | |
388 ciEnv* env = ciEnv::current(); | |
389 ciObject* ciargs[max_arg_count]; | |
390 assert(nargs <= max_arg_count, "oob"); | |
391 for (int j = 0; j < nargs; j++) { | |
392 ciargs[j] = env->get_object(args[j]); | |
393 } | |
394 Dependencies::write_dependency_to(log, dept, nargs, ciargs, witness); | |
395 } | |
396 | |
397 void Dependencies::write_dependency_to(CompileLog* log, | |
398 DepType dept, | |
399 int nargs, ciObject* args[], | |
400 klassOop witness) { | |
401 if (log == NULL) return; | |
402 assert(nargs <= max_arg_count, "oob"); | |
403 int argids[max_arg_count]; | |
404 int ctxkj = dep_context_arg(dept); // -1 if no context arg | |
405 int j; | |
406 for (j = 0; j < nargs; j++) { | |
407 argids[j] = log->identify(args[j]); | |
408 } | |
409 if (witness != NULL) { | |
410 log->begin_elem("dependency_failed"); | |
411 } else { | |
412 log->begin_elem("dependency"); | |
413 } | |
414 log->print(" type='%s'", dep_name(dept)); | |
415 if (ctxkj >= 0) { | |
416 log->print(" ctxk='%d'", argids[ctxkj]); | |
417 } | |
418 // write remaining arguments, if any. | |
419 for (j = 0; j < nargs; j++) { | |
420 if (j == ctxkj) continue; // already logged | |
421 if (j == 1) { | |
422 log->print( " x='%d'", argids[j]); | |
423 } else { | |
424 log->print(" x%d='%d'", j, argids[j]); | |
425 } | |
426 } | |
427 if (witness != NULL) { | |
428 log->object("witness", witness); | |
429 log->stamp(); | |
430 } | |
431 log->end_elem(); | |
432 } | |
433 | |
434 void Dependencies::write_dependency_to(xmlStream* xtty, | |
435 DepType dept, | |
436 int nargs, oop args[], | |
437 klassOop witness) { | |
438 if (xtty == NULL) return; | |
439 ttyLocker ttyl; | |
440 int ctxkj = dep_context_arg(dept); // -1 if no context arg | |
441 if (witness != NULL) { | |
442 xtty->begin_elem("dependency_failed"); | |
443 } else { | |
444 xtty->begin_elem("dependency"); | |
445 } | |
446 xtty->print(" type='%s'", dep_name(dept)); | |
447 if (ctxkj >= 0) { | |
448 xtty->object("ctxk", args[ctxkj]); | |
449 } | |
450 // write remaining arguments, if any. | |
451 for (int j = 0; j < nargs; j++) { | |
452 if (j == ctxkj) continue; // already logged | |
453 if (j == 1) { | |
454 xtty->object("x", args[j]); | |
455 } else { | |
456 char xn[10]; sprintf(xn, "x%d", j); | |
457 xtty->object(xn, args[j]); | |
458 } | |
459 } | |
460 if (witness != NULL) { | |
461 xtty->object("witness", witness); | |
462 xtty->stamp(); | |
463 } | |
464 xtty->end_elem(); | |
465 } | |
466 | |
467 void Dependencies::print_dependency(DepType dept, int nargs, oop args[], | |
468 klassOop witness) { | |
469 ResourceMark rm; | |
470 ttyLocker ttyl; // keep the following output all in one block | |
471 tty->print_cr("%s of type %s", | |
472 (witness == NULL)? "Dependency": "Failed dependency", | |
473 dep_name(dept)); | |
474 // print arguments | |
475 int ctxkj = dep_context_arg(dept); // -1 if no context arg | |
476 for (int j = 0; j < nargs; j++) { | |
477 oop arg = args[j]; | |
478 bool put_star = false; | |
479 if (arg == NULL) continue; | |
480 const char* what; | |
481 if (j == ctxkj) { | |
482 what = "context"; | |
483 put_star = !Dependencies::is_concrete_klass((klassOop)arg); | |
484 } else if (arg->is_method()) { | |
485 what = "method "; | |
486 put_star = !Dependencies::is_concrete_method((methodOop)arg); | |
487 } else if (arg->is_klass()) { | |
488 what = "class "; | |
489 } else { | |
490 what = "object "; | |
491 } | |
492 tty->print(" %s = %s", what, (put_star? "*": "")); | |
493 if (arg->is_klass()) | |
494 tty->print("%s", Klass::cast((klassOop)arg)->external_name()); | |
495 else | |
496 arg->print_value(); | |
497 tty->cr(); | |
498 } | |
499 if (witness != NULL) { | |
500 bool put_star = !Dependencies::is_concrete_klass(witness); | |
501 tty->print_cr(" witness = %s%s", | |
502 (put_star? "*": ""), | |
503 Klass::cast(witness)->external_name()); | |
504 } | |
505 } | |
506 | |
507 void Dependencies::DepStream::log_dependency(klassOop witness) { | |
508 if (_deps == NULL && xtty == NULL) return; // fast cutout for runtime | |
509 int nargs = argument_count(); | |
510 oop args[max_arg_count]; | |
511 for (int j = 0; j < nargs; j++) { | |
512 args[j] = argument(j); | |
513 } | |
514 if (_deps != NULL && _deps->log() != NULL) { | |
515 Dependencies::write_dependency_to(_deps->log(), | |
516 type(), nargs, args, witness); | |
517 } else { | |
518 Dependencies::write_dependency_to(xtty, | |
519 type(), nargs, args, witness); | |
520 } | |
521 } | |
522 | |
523 void Dependencies::DepStream::print_dependency(klassOop witness, bool verbose) { | |
524 int nargs = argument_count(); | |
525 oop args[max_arg_count]; | |
526 for (int j = 0; j < nargs; j++) { | |
527 args[j] = argument(j); | |
528 } | |
529 Dependencies::print_dependency(type(), nargs, args, witness); | |
530 if (verbose) { | |
531 if (_code != NULL) { | |
532 tty->print(" code: "); | |
533 _code->print_value_on(tty); | |
534 tty->cr(); | |
535 } | |
536 } | |
537 } | |
538 | |
539 | |
540 /// Dependency stream support (decodes dependencies from an nmethod): | |
541 | |
542 #ifdef ASSERT | |
543 void Dependencies::DepStream::initial_asserts(size_t byte_limit) { | |
544 assert(must_be_in_vm(), "raw oops here"); | |
545 _byte_limit = byte_limit; | |
546 _type = (DepType)(end_marker-1); // defeat "already at end" assert | |
547 assert((_code!=NULL) + (_deps!=NULL) == 1, "one or t'other"); | |
548 } | |
549 #endif //ASSERT | |
550 | |
551 bool Dependencies::DepStream::next() { | |
552 assert(_type != end_marker, "already at end"); | |
553 if (_bytes.position() == 0 && _code != NULL | |
554 && _code->dependencies_size() == 0) { | |
555 // Method has no dependencies at all. | |
556 return false; | |
557 } | |
558 int code_byte = (_bytes.read_byte() & 0xFF); | |
559 if (code_byte == end_marker) { | |
560 DEBUG_ONLY(_type = end_marker); | |
561 return false; | |
562 } else { | |
563 int ctxk_bit = (code_byte & Dependencies::default_context_type_bit); | |
564 code_byte -= ctxk_bit; | |
565 DepType dept = (DepType)code_byte; | |
566 _type = dept; | |
567 guarantee((dept - FIRST_TYPE) < (TYPE_LIMIT - FIRST_TYPE), | |
568 "bad dependency type tag"); | |
569 int stride = _dep_args[dept]; | |
570 assert(stride == dep_args(dept), "sanity"); | |
571 int skipj = -1; | |
572 if (ctxk_bit != 0) { | |
573 skipj = 0; // currently the only context argument is at zero | |
574 assert(skipj == dep_context_arg(dept), "zero arg always ctxk"); | |
575 } | |
576 for (int j = 0; j < stride; j++) { | |
577 _xi[j] = (j == skipj)? 0: _bytes.read_int(); | |
578 } | |
579 DEBUG_ONLY(_xi[stride] = -1); // help detect overruns | |
580 return true; | |
581 } | |
582 } | |
583 | |
584 inline oop Dependencies::DepStream::recorded_oop_at(int i) { | |
585 return (_code != NULL) | |
586 ? _code->oop_at(i) | |
587 : JNIHandles::resolve(_deps->oop_recorder()->handle_at(i)); | |
588 } | |
589 | |
590 oop Dependencies::DepStream::argument(int i) { | |
591 return recorded_oop_at(argument_index(i)); | |
592 } | |
593 | |
594 klassOop Dependencies::DepStream::context_type() { | |
595 assert(must_be_in_vm(), "raw oops here"); | |
596 int ctxkj = dep_context_arg(_type); // -1 if no context arg | |
597 if (ctxkj < 0) { | |
598 return NULL; // for example, evol_method | |
599 } else { | |
600 oop k = recorded_oop_at(_xi[ctxkj]); | |
601 if (k != NULL) { // context type was not compressed away | |
602 assert(k->is_klass(), "type check"); | |
603 return (klassOop) k; | |
604 } else { // recompute "default" context type | |
605 return ctxk_encoded_as_null(_type, recorded_oop_at(_xi[ctxkj+1])); | |
606 } | |
607 } | |
608 } | |
609 | |
610 /// Checking dependencies: | |
611 | |
612 // This hierarchy walker inspects subtypes of a given type, | |
613 // trying to find a "bad" class which breaks a dependency. | |
614 // Such a class is called a "witness" to the broken dependency. | |
615 // While searching around, we ignore "participants", which | |
616 // are already known to the dependency. | |
617 class ClassHierarchyWalker { | |
618 public: | |
619 enum { PARTICIPANT_LIMIT = 3 }; | |
620 | |
621 private: | |
622 // optional method descriptor to check for: | |
623 symbolOop _name; | |
624 symbolOop _signature; | |
625 | |
626 // special classes which are not allowed to be witnesses: | |
627 klassOop _participants[PARTICIPANT_LIMIT+1]; | |
628 int _num_participants; | |
629 | |
630 // cache of method lookups | |
631 methodOop _found_methods[PARTICIPANT_LIMIT+1]; | |
632 | |
633 // if non-zero, tells how many witnesses to convert to participants | |
634 int _record_witnesses; | |
635 | |
636 void initialize(klassOop participant) { | |
637 _record_witnesses = 0; | |
638 _participants[0] = participant; | |
639 _found_methods[0] = NULL; | |
640 _num_participants = 0; | |
641 if (participant != NULL) { | |
642 // Terminating NULL. | |
643 _participants[1] = NULL; | |
644 _found_methods[1] = NULL; | |
645 _num_participants = 1; | |
646 } | |
647 } | |
648 | |
649 void initialize_from_method(methodOop m) { | |
650 assert(m != NULL && m->is_method(), "sanity"); | |
651 _name = m->name(); | |
652 _signature = m->signature(); | |
653 } | |
654 | |
655 public: | |
656 // The walker is initialized to recognize certain methods and/or types | |
657 // as friendly participants. | |
658 ClassHierarchyWalker(klassOop participant, methodOop m) { | |
659 initialize_from_method(m); | |
660 initialize(participant); | |
661 } | |
662 ClassHierarchyWalker(methodOop m) { | |
663 initialize_from_method(m); | |
664 initialize(NULL); | |
665 } | |
666 ClassHierarchyWalker(klassOop participant = NULL) { | |
667 _name = NULL; | |
668 _signature = NULL; | |
669 initialize(participant); | |
670 } | |
671 | |
672 // This is common code for two searches: One for concrete subtypes, | |
673 // the other for concrete method implementations and overrides. | |
674 bool doing_subtype_search() { | |
675 return _name == NULL; | |
676 } | |
677 | |
678 int num_participants() { return _num_participants; } | |
679 klassOop participant(int n) { | |
680 assert((uint)n <= (uint)_num_participants, "oob"); | |
681 return _participants[n]; | |
682 } | |
683 | |
684 // Note: If n==num_participants, returns NULL. | |
685 methodOop found_method(int n) { | |
686 assert((uint)n <= (uint)_num_participants, "oob"); | |
687 methodOop fm = _found_methods[n]; | |
688 assert(n == _num_participants || fm != NULL, "proper usage"); | |
689 assert(fm == NULL || fm->method_holder() == _participants[n], "sanity"); | |
690 return fm; | |
691 } | |
692 | |
693 #ifdef ASSERT | |
694 // Assert that m is inherited into ctxk, without intervening overrides. | |
695 // (May return true even if this is not true, in corner cases where we punt.) | |
696 bool check_method_context(klassOop ctxk, methodOop m) { | |
697 if (m->method_holder() == ctxk) | |
698 return true; // Quick win. | |
699 if (m->is_private()) | |
700 return false; // Quick lose. Should not happen. | |
701 if (!(m->is_public() || m->is_protected())) | |
702 // The override story is complex when packages get involved. | |
703 return true; // Must punt the assertion to true. | |
704 Klass* k = Klass::cast(ctxk); | |
705 methodOop lm = k->lookup_method(m->name(), m->signature()); | |
706 if (lm == NULL && k->oop_is_instance()) { | |
707 // It might be an abstract interface method, devoid of mirandas. | |
708 lm = ((instanceKlass*)k)->lookup_method_in_all_interfaces(m->name(), | |
709 m->signature()); | |
710 } | |
711 if (lm == m) | |
712 // Method m is inherited into ctxk. | |
713 return true; | |
714 if (lm != NULL) { | |
715 if (!(lm->is_public() || lm->is_protected())) | |
716 // Method is [package-]private, so the override story is complex. | |
717 return true; // Must punt the assertion to true. | |
718 if ( !Dependencies::is_concrete_method(lm) | |
719 && !Dependencies::is_concrete_method(m) | |
720 && Klass::cast(lm->method_holder())->is_subtype_of(m->method_holder())) | |
721 // Method m is overridden by lm, but both are non-concrete. | |
722 return true; | |
723 } | |
724 ResourceMark rm; | |
725 tty->print_cr("Dependency method not found in the associated context:"); | |
726 tty->print_cr(" context = %s", Klass::cast(ctxk)->external_name()); | |
727 tty->print( " method = "); m->print_short_name(tty); tty->cr(); | |
728 if (lm != NULL) { | |
729 tty->print( " found = "); lm->print_short_name(tty); tty->cr(); | |
730 } | |
731 return false; | |
732 } | |
733 #endif | |
734 | |
735 void add_participant(klassOop participant) { | |
736 assert(_num_participants + _record_witnesses < PARTICIPANT_LIMIT, "oob"); | |
737 int np = _num_participants++; | |
738 _participants[np] = participant; | |
739 _participants[np+1] = NULL; | |
740 _found_methods[np+1] = NULL; | |
741 } | |
742 | |
743 void record_witnesses(int add) { | |
744 if (add > PARTICIPANT_LIMIT) add = PARTICIPANT_LIMIT; | |
745 assert(_num_participants + add < PARTICIPANT_LIMIT, "oob"); | |
746 _record_witnesses = add; | |
747 } | |
748 | |
749 bool is_witness(klassOop k) { | |
750 if (doing_subtype_search()) { | |
751 return Dependencies::is_concrete_klass(k); | |
752 } else { | |
753 methodOop m = instanceKlass::cast(k)->find_method(_name, _signature); | |
754 if (m == NULL || !Dependencies::is_concrete_method(m)) return false; | |
755 _found_methods[_num_participants] = m; | |
756 // Note: If add_participant(k) is called, | |
757 // the method m will already be memoized for it. | |
758 return true; | |
759 } | |
760 } | |
761 | |
762 bool is_participant(klassOop k) { | |
763 if (k == _participants[0]) { | |
764 return true; | |
765 } else if (_num_participants <= 1) { | |
766 return false; | |
767 } else { | |
768 return in_list(k, &_participants[1]); | |
769 } | |
770 } | |
771 bool ignore_witness(klassOop witness) { | |
772 if (_record_witnesses == 0) { | |
773 return false; | |
774 } else { | |
775 --_record_witnesses; | |
776 add_participant(witness); | |
777 return true; | |
778 } | |
779 } | |
780 static bool in_list(klassOop x, klassOop* list) { | |
781 for (int i = 0; ; i++) { | |
782 klassOop y = list[i]; | |
783 if (y == NULL) break; | |
784 if (y == x) return true; | |
785 } | |
786 return false; // not in list | |
787 } | |
788 | |
789 private: | |
790 // the actual search method: | |
791 klassOop find_witness_anywhere(klassOop context_type, | |
792 bool participants_hide_witnesses, | |
793 bool top_level_call = true); | |
794 // the spot-checking version: | |
795 klassOop find_witness_in(DepChange& changes, | |
796 klassOop context_type, | |
797 bool participants_hide_witnesses); | |
798 public: | |
799 klassOop find_witness_subtype(klassOop context_type, DepChange* changes = NULL) { | |
800 assert(doing_subtype_search(), "must set up a subtype search"); | |
801 // When looking for unexpected concrete types, | |
802 // do not look beneath expected ones. | |
803 const bool participants_hide_witnesses = true; | |
804 // CX > CC > C' is OK, even if C' is new. | |
805 // CX > { CC, C' } is not OK if C' is new, and C' is the witness. | |
806 if (changes != NULL) { | |
807 return find_witness_in(*changes, context_type, participants_hide_witnesses); | |
808 } else { | |
809 return find_witness_anywhere(context_type, participants_hide_witnesses); | |
810 } | |
811 } | |
812 klassOop find_witness_definer(klassOop context_type, DepChange* changes = NULL) { | |
813 assert(!doing_subtype_search(), "must set up a method definer search"); | |
814 // When looking for unexpected concrete methods, | |
815 // look beneath expected ones, to see if there are overrides. | |
816 const bool participants_hide_witnesses = true; | |
817 // CX.m > CC.m > C'.m is not OK, if C'.m is new, and C' is the witness. | |
818 if (changes != NULL) { | |
819 return find_witness_in(*changes, context_type, !participants_hide_witnesses); | |
820 } else { | |
821 return find_witness_anywhere(context_type, !participants_hide_witnesses); | |
822 } | |
823 } | |
824 }; | |
825 | |
826 #ifndef PRODUCT | |
827 static int deps_find_witness_calls = 0; | |
828 static int deps_find_witness_steps = 0; | |
829 static int deps_find_witness_recursions = 0; | |
830 static int deps_find_witness_singles = 0; | |
831 static int deps_find_witness_print = 0; // set to -1 to force a final print | |
832 static bool count_find_witness_calls() { | |
833 if (TraceDependencies || LogCompilation) { | |
834 int pcount = deps_find_witness_print + 1; | |
835 bool final_stats = (pcount == 0); | |
836 bool initial_call = (pcount == 1); | |
837 bool occasional_print = ((pcount & ((1<<10) - 1)) == 0); | |
838 if (pcount < 0) pcount = 1; // crude overflow protection | |
839 deps_find_witness_print = pcount; | |
840 if (VerifyDependencies && initial_call) { | |
841 tty->print_cr("Warning: TraceDependencies results may be inflated by VerifyDependencies"); | |
842 } | |
843 if (occasional_print || final_stats) { | |
844 // Every now and then dump a little info about dependency searching. | |
845 if (xtty != NULL) { | |
846 xtty->elem("deps_find_witness calls='%d' steps='%d' recursions='%d' singles='%d'", | |
847 deps_find_witness_calls, | |
848 deps_find_witness_steps, | |
849 deps_find_witness_recursions, | |
850 deps_find_witness_singles); | |
851 } | |
852 if (final_stats || (TraceDependencies && WizardMode)) { | |
853 tty->print_cr("Dependency check (find_witness) " | |
854 "calls=%d, steps=%d (avg=%.1f), recursions=%d, singles=%d", | |
855 deps_find_witness_calls, | |
856 deps_find_witness_steps, | |
857 (double)deps_find_witness_steps / deps_find_witness_calls, | |
858 deps_find_witness_recursions, | |
859 deps_find_witness_singles); | |
860 } | |
861 } | |
862 return true; | |
863 } | |
864 return false; | |
865 } | |
866 #else | |
867 #define count_find_witness_calls() (0) | |
868 #endif //PRODUCT | |
869 | |
870 | |
871 klassOop ClassHierarchyWalker::find_witness_in(DepChange& changes, | |
872 klassOop context_type, | |
873 bool participants_hide_witnesses) { | |
874 assert(changes.involves_context(context_type), "irrelevant dependency"); | |
875 klassOop new_type = changes.new_type(); | |
876 | |
877 count_find_witness_calls(); | |
878 NOT_PRODUCT(deps_find_witness_singles++); | |
879 | |
880 // Current thread must be in VM (not native mode, as in CI): | |
881 assert(must_be_in_vm(), "raw oops here"); | |
882 // Must not move the class hierarchy during this check: | |
883 assert_locked_or_safepoint(Compile_lock); | |
884 | |
885 assert(!is_participant(new_type), "only old classes are participants"); | |
886 if (participants_hide_witnesses) { | |
887 // If the new type is a subtype of a participant, we are done. | |
888 for (int i = 0; i < num_participants(); i++) { | |
889 klassOop part = participant(i); | |
890 if (part == NULL) continue; | |
891 assert(changes.involves_context(part) == Klass::cast(new_type)->is_subtype_of(part), | |
892 "correct marking of participants, b/c new_type is unique"); | |
893 if (changes.involves_context(part)) { | |
894 // new guy is protected from this check by previous participant | |
895 return NULL; | |
896 } | |
897 } | |
898 } | |
899 | |
900 if (is_witness(new_type) && | |
901 !ignore_witness(new_type)) { | |
902 return new_type; | |
903 } | |
904 | |
905 return NULL; | |
906 } | |
907 | |
908 | |
909 // Walk hierarchy under a context type, looking for unexpected types. | |
910 // Do not report participant types, and recursively walk beneath | |
911 // them only if participants_hide_witnesses is false. | |
912 // If top_level_call is false, skip testing the context type, | |
913 // because the caller has already considered it. | |
914 klassOop ClassHierarchyWalker::find_witness_anywhere(klassOop context_type, | |
915 bool participants_hide_witnesses, | |
916 bool top_level_call) { | |
917 // Current thread must be in VM (not native mode, as in CI): | |
918 assert(must_be_in_vm(), "raw oops here"); | |
919 // Must not move the class hierarchy during this check: | |
920 assert_locked_or_safepoint(Compile_lock); | |
921 | |
922 bool do_counts = count_find_witness_calls(); | |
923 | |
924 // Check the root of the sub-hierarchy first. | |
925 if (top_level_call) { | |
926 if (do_counts) { | |
927 NOT_PRODUCT(deps_find_witness_calls++); | |
928 NOT_PRODUCT(deps_find_witness_steps++); | |
929 } | |
930 if (is_participant(context_type)) { | |
931 if (participants_hide_witnesses) return NULL; | |
932 // else fall through to search loop... | |
933 } else if (is_witness(context_type) && !ignore_witness(context_type)) { | |
934 // The context is an abstract class or interface, to start with. | |
935 return context_type; | |
936 } | |
937 } | |
938 | |
939 // Now we must check each implementor and each subclass. | |
940 // Use a short worklist to avoid blowing the stack. | |
941 // Each worklist entry is a *chain* of subklass siblings to process. | |
942 const int CHAINMAX = 100; // >= 1 + instanceKlass::implementors_limit | |
943 Klass* chains[CHAINMAX]; | |
944 int chaini = 0; // index into worklist | |
945 Klass* chain; // scratch variable | |
946 #define ADD_SUBCLASS_CHAIN(k) { \ | |
947 assert(chaini < CHAINMAX, "oob"); \ | |
948 chain = instanceKlass::cast(k)->subklass(); \ | |
949 if (chain != NULL) chains[chaini++] = chain; } | |
950 | |
951 // Look for non-abstract subclasses. | |
952 // (Note: Interfaces do not have subclasses.) | |
953 ADD_SUBCLASS_CHAIN(context_type); | |
954 | |
955 // If it is an interface, search its direct implementors. | |
956 // (Their subclasses are additional indirect implementors. | |
957 // See instanceKlass::add_implementor.) | |
958 // (Note: nof_implementors is always zero for non-interfaces.) | |
959 int nof_impls = instanceKlass::cast(context_type)->nof_implementors(); | |
960 if (nof_impls > 1) { | |
961 // Avoid this case: *I.m > { A.m, C }; B.m > C | |
962 // Here, I.m has 2 concrete implementations, but m appears unique | |
963 // as A.m, because the search misses B.m when checking C. | |
964 // The inherited method B.m was getting missed by the walker | |
965 // when interface 'I' was the starting point. | |
966 // %%% Until this is fixed more systematically, bail out. | |
967 // (Old CHA had the same limitation.) | |
968 return context_type; | |
969 } | |
970 for (int i = 0; i < nof_impls; i++) { | |
971 klassOop impl = instanceKlass::cast(context_type)->implementor(i); | |
972 if (impl == NULL) { | |
973 // implementors array overflowed => no exact info. | |
974 return context_type; // report an inexact witness to this sad affair | |
975 } | |
976 if (do_counts) | |
977 { NOT_PRODUCT(deps_find_witness_steps++); } | |
978 if (is_participant(impl)) { | |
979 if (participants_hide_witnesses) continue; | |
980 // else fall through to process this guy's subclasses | |
981 } else if (is_witness(impl) && !ignore_witness(impl)) { | |
982 return impl; | |
983 } | |
984 ADD_SUBCLASS_CHAIN(impl); | |
985 } | |
986 | |
987 // Recursively process each non-trivial sibling chain. | |
988 while (chaini > 0) { | |
989 Klass* chain = chains[--chaini]; | |
990 for (Klass* subk = chain; subk != NULL; subk = subk->next_sibling()) { | |
991 klassOop sub = subk->as_klassOop(); | |
992 if (do_counts) { NOT_PRODUCT(deps_find_witness_steps++); } | |
993 if (is_participant(sub)) { | |
994 if (participants_hide_witnesses) continue; | |
995 // else fall through to process this guy's subclasses | |
996 } else if (is_witness(sub) && !ignore_witness(sub)) { | |
997 return sub; | |
998 } | |
999 if (chaini < (VerifyDependencies? 2: CHAINMAX)) { | |
1000 // Fast path. (Partially disabled if VerifyDependencies.) | |
1001 ADD_SUBCLASS_CHAIN(sub); | |
1002 } else { | |
1003 // Worklist overflow. Do a recursive call. Should be rare. | |
1004 // The recursive call will have its own worklist, of course. | |
1005 // (Note that sub has already been tested, so that there is | |
1006 // no need for the recursive call to re-test. That's handy, | |
1007 // since the recursive call sees sub as the context_type.) | |
1008 if (do_counts) { NOT_PRODUCT(deps_find_witness_recursions++); } | |
1009 klassOop witness = find_witness_anywhere(sub, | |
1010 participants_hide_witnesses, | |
1011 /*top_level_call=*/ false); | |
1012 if (witness != NULL) return witness; | |
1013 } | |
1014 } | |
1015 } | |
1016 | |
1017 // No witness found. The dependency remains unbroken. | |
1018 return NULL; | |
1019 #undef ADD_SUBCLASS_CHAIN | |
1020 } | |
1021 | |
1022 | |
1023 bool Dependencies::is_concrete_klass(klassOop k) { | |
1024 if (Klass::cast(k)->is_abstract()) return false; | |
1025 // %%% We could treat classes which are concrete but | |
1026 // have not yet been instantiated as virtually abstract. | |
1027 // This would require a deoptimization barrier on first instantiation. | |
1028 //if (k->is_not_instantiated()) return false; | |
1029 return true; | |
1030 } | |
1031 | |
1032 bool Dependencies::is_concrete_method(methodOop m) { | |
1033 if (m->is_abstract()) return false; | |
1034 // %%% We could treat unexecuted methods as virtually abstract also. | |
1035 // This would require a deoptimization barrier on first execution. | |
1036 return !m->is_abstract(); | |
1037 } | |
1038 | |
1039 | |
1040 Klass* Dependencies::find_finalizable_subclass(Klass* k) { | |
1041 if (k->is_interface()) return NULL; | |
1042 if (k->has_finalizer()) return k; | |
1043 k = k->subklass(); | |
1044 while (k != NULL) { | |
1045 Klass* result = find_finalizable_subclass(k); | |
1046 if (result != NULL) return result; | |
1047 k = k->next_sibling(); | |
1048 } | |
1049 return NULL; | |
1050 } | |
1051 | |
1052 | |
1053 bool Dependencies::is_concrete_klass(ciInstanceKlass* k) { | |
1054 if (k->is_abstract()) return false; | |
1055 // We could return also false if k does not yet appear to be | |
1056 // instantiated, if the VM version supports this distinction also. | |
1057 //if (k->is_not_instantiated()) return false; | |
1058 return true; | |
1059 } | |
1060 | |
1061 bool Dependencies::is_concrete_method(ciMethod* m) { | |
1062 // Statics are irrelevant to virtual call sites. | |
1063 if (m->is_static()) return false; | |
1064 | |
1065 // We could return also false if m does not yet appear to be | |
1066 // executed, if the VM version supports this distinction also. | |
1067 return !m->is_abstract(); | |
1068 } | |
1069 | |
1070 | |
1071 bool Dependencies::has_finalizable_subclass(ciInstanceKlass* k) { | |
1072 return k->has_finalizable_subclass(); | |
1073 } | |
1074 | |
1075 | |
1076 // Any use of the contents (bytecodes) of a method must be | |
1077 // marked by an "evol_method" dependency, if those contents | |
1078 // can change. (Note: A method is always dependent on itself.) | |
1079 klassOop Dependencies::check_evol_method(methodOop m) { | |
1080 assert(must_be_in_vm(), "raw oops here"); | |
1081 // Did somebody do a JVMTI RedefineClasses while our backs were turned? | |
1082 // Or is there a now a breakpoint? | |
1083 // (Assumes compiled code cannot handle bkpts; change if UseFastBreakpoints.) | |
1084 if (m->is_old() | |
1085 || m->number_of_breakpoints() > 0) { | |
1086 return m->method_holder(); | |
1087 } else { | |
1088 return NULL; | |
1089 } | |
1090 } | |
1091 | |
1092 // This is a strong assertion: It is that the given type | |
1093 // has no subtypes whatever. It is most useful for | |
1094 // optimizing checks on reflected types or on array types. | |
1095 // (Checks on types which are derived from real instances | |
1096 // can be optimized more strongly than this, because we | |
1097 // know that the checked type comes from a concrete type, | |
1098 // and therefore we can disregard abstract types.) | |
1099 klassOop Dependencies::check_leaf_type(klassOop ctxk) { | |
1100 assert(must_be_in_vm(), "raw oops here"); | |
1101 assert_locked_or_safepoint(Compile_lock); | |
1102 instanceKlass* ctx = instanceKlass::cast(ctxk); | |
1103 Klass* sub = ctx->subklass(); | |
1104 if (sub != NULL) { | |
1105 return sub->as_klassOop(); | |
1106 } else if (ctx->nof_implementors() != 0) { | |
1107 // if it is an interface, it must be unimplemented | |
1108 // (if it is not an interface, nof_implementors is always zero) | |
1109 klassOop impl = ctx->implementor(0); | |
1110 return (impl != NULL)? impl: ctxk; | |
1111 } else { | |
1112 return NULL; | |
1113 } | |
1114 } | |
1115 | |
1116 // Test the assertion that conck is the only concrete subtype* of ctxk. | |
1117 // The type conck itself is allowed to have have further concrete subtypes. | |
1118 // This allows the compiler to narrow occurrences of ctxk by conck, | |
1119 // when dealing with the types of actual instances. | |
1120 klassOop Dependencies::check_abstract_with_unique_concrete_subtype(klassOop ctxk, | |
1121 klassOop conck, | |
1122 DepChange* changes) { | |
1123 ClassHierarchyWalker wf(conck); | |
1124 return wf.find_witness_subtype(ctxk, changes); | |
1125 } | |
1126 | |
1127 // If a non-concrete class has no concrete subtypes, it is not (yet) | |
1128 // instantiatable. This can allow the compiler to make some paths go | |
1129 // dead, if they are gated by a test of the type. | |
1130 klassOop Dependencies::check_abstract_with_no_concrete_subtype(klassOop ctxk, | |
1131 DepChange* changes) { | |
1132 // Find any concrete subtype, with no participants: | |
1133 ClassHierarchyWalker wf; | |
1134 return wf.find_witness_subtype(ctxk, changes); | |
1135 } | |
1136 | |
1137 | |
1138 // If a concrete class has no concrete subtypes, it can always be | |
1139 // exactly typed. This allows the use of a cheaper type test. | |
1140 klassOop Dependencies::check_concrete_with_no_concrete_subtype(klassOop ctxk, | |
1141 DepChange* changes) { | |
1142 // Find any concrete subtype, with only the ctxk as participant: | |
1143 ClassHierarchyWalker wf(ctxk); | |
1144 return wf.find_witness_subtype(ctxk, changes); | |
1145 } | |
1146 | |
1147 | |
1148 // Find the unique concrete proper subtype of ctxk, or NULL if there | |
1149 // is more than one concrete proper subtype. If there are no concrete | |
1150 // proper subtypes, return ctxk itself, whether it is concrete or not. | |
1151 // The returned subtype is allowed to have have further concrete subtypes. | |
1152 // That is, return CC1 for CX > CC1 > CC2, but NULL for CX > { CC1, CC2 }. | |
1153 klassOop Dependencies::find_unique_concrete_subtype(klassOop ctxk) { | |
1154 ClassHierarchyWalker wf(ctxk); // Ignore ctxk when walking. | |
1155 wf.record_witnesses(1); // Record one other witness when walking. | |
1156 klassOop wit = wf.find_witness_subtype(ctxk); | |
1157 if (wit != NULL) return NULL; // Too many witnesses. | |
1158 klassOop conck = wf.participant(0); | |
1159 if (conck == NULL) { | |
1160 #ifndef PRODUCT | |
1161 // Make sure the dependency mechanism will pass this discovery: | |
1162 if (VerifyDependencies) { | |
1163 // Turn off dependency tracing while actually testing deps. | |
1164 FlagSetting fs(TraceDependencies, false); | |
1165 if (!Dependencies::is_concrete_klass(ctxk)) { | |
1166 guarantee(NULL == | |
1167 (void *)check_abstract_with_no_concrete_subtype(ctxk), | |
1168 "verify dep."); | |
1169 } else { | |
1170 guarantee(NULL == | |
1171 (void *)check_concrete_with_no_concrete_subtype(ctxk), | |
1172 "verify dep."); | |
1173 } | |
1174 } | |
1175 #endif //PRODUCT | |
1176 return ctxk; // Return ctxk as a flag for "no subtypes". | |
1177 } else { | |
1178 #ifndef PRODUCT | |
1179 // Make sure the dependency mechanism will pass this discovery: | |
1180 if (VerifyDependencies) { | |
1181 // Turn off dependency tracing while actually testing deps. | |
1182 FlagSetting fs(TraceDependencies, false); | |
1183 if (!Dependencies::is_concrete_klass(ctxk)) { | |
1184 guarantee(NULL == (void *) | |
1185 check_abstract_with_unique_concrete_subtype(ctxk, conck), | |
1186 "verify dep."); | |
1187 } | |
1188 } | |
1189 #endif //PRODUCT | |
1190 return conck; | |
1191 } | |
1192 } | |
1193 | |
1194 // Test the assertion that the k[12] are the only concrete subtypes of ctxk, | |
1195 // except possibly for further subtypes of k[12] themselves. | |
1196 // The context type must be abstract. The types k1 and k2 are themselves | |
1197 // allowed to have further concrete subtypes. | |
1198 klassOop Dependencies::check_abstract_with_exclusive_concrete_subtypes( | |
1199 klassOop ctxk, | |
1200 klassOop k1, | |
1201 klassOop k2, | |
1202 DepChange* changes) { | |
1203 ClassHierarchyWalker wf; | |
1204 wf.add_participant(k1); | |
1205 wf.add_participant(k2); | |
1206 return wf.find_witness_subtype(ctxk, changes); | |
1207 } | |
1208 | |
1209 // Search ctxk for concrete implementations. If there are klen or fewer, | |
1210 // pack them into the given array and return the number. | |
1211 // Otherwise, return -1, meaning the given array would overflow. | |
1212 // (Note that a return of 0 means there are exactly no concrete subtypes.) | |
1213 // In this search, if ctxk is concrete, it will be reported alone. | |
1214 // For any type CC reported, no proper subtypes of CC will be reported. | |
1215 int Dependencies::find_exclusive_concrete_subtypes(klassOop ctxk, | |
1216 int klen, | |
1217 klassOop karray[]) { | |
1218 ClassHierarchyWalker wf; | |
1219 wf.record_witnesses(klen); | |
1220 klassOop wit = wf.find_witness_subtype(ctxk); | |
1221 if (wit != NULL) return -1; // Too many witnesses. | |
1222 int num = wf.num_participants(); | |
1223 assert(num <= klen, "oob"); | |
1224 // Pack the result array with the good news. | |
1225 for (int i = 0; i < num; i++) | |
1226 karray[i] = wf.participant(i); | |
1227 #ifndef PRODUCT | |
1228 // Make sure the dependency mechanism will pass this discovery: | |
1229 if (VerifyDependencies) { | |
1230 // Turn off dependency tracing while actually testing deps. | |
1231 FlagSetting fs(TraceDependencies, false); | |
1232 switch (Dependencies::is_concrete_klass(ctxk)? -1: num) { | |
1233 case -1: // ctxk was itself concrete | |
1234 guarantee(num == 1 && karray[0] == ctxk, "verify dep."); | |
1235 break; | |
1236 case 0: | |
1237 guarantee(NULL == (void *)check_abstract_with_no_concrete_subtype(ctxk), | |
1238 "verify dep."); | |
1239 break; | |
1240 case 1: | |
1241 guarantee(NULL == (void *) | |
1242 check_abstract_with_unique_concrete_subtype(ctxk, karray[0]), | |
1243 "verify dep."); | |
1244 break; | |
1245 case 2: | |
1246 guarantee(NULL == (void *) | |
1247 check_abstract_with_exclusive_concrete_subtypes(ctxk, | |
1248 karray[0], | |
1249 karray[1]), | |
1250 "verify dep."); | |
1251 break; | |
1252 default: | |
1253 ShouldNotReachHere(); // klen > 2 yet supported | |
1254 } | |
1255 } | |
1256 #endif //PRODUCT | |
1257 return num; | |
1258 } | |
1259 | |
1260 // If a class (or interface) has a unique concrete method uniqm, return NULL. | |
1261 // Otherwise, return a class that contains an interfering method. | |
1262 klassOop Dependencies::check_unique_concrete_method(klassOop ctxk, methodOop uniqm, | |
1263 DepChange* changes) { | |
1264 // Here is a missing optimization: If uniqm->is_final(), | |
1265 // we don't really need to search beneath it for overrides. | |
1266 // This is probably not important, since we don't use dependencies | |
1267 // to track final methods. (They can't be "definalized".) | |
1268 ClassHierarchyWalker wf(uniqm->method_holder(), uniqm); | |
1269 return wf.find_witness_definer(ctxk, changes); | |
1270 } | |
1271 | |
1272 // Find the set of all non-abstract methods under ctxk that match m. | |
1273 // (The method m must be defined or inherited in ctxk.) | |
1274 // Include m itself in the set, unless it is abstract. | |
1275 // If this set has exactly one element, return that element. | |
1276 methodOop Dependencies::find_unique_concrete_method(klassOop ctxk, methodOop m) { | |
1277 ClassHierarchyWalker wf(m); | |
1278 assert(wf.check_method_context(ctxk, m), "proper context"); | |
1279 wf.record_witnesses(1); | |
1280 klassOop wit = wf.find_witness_definer(ctxk); | |
1281 if (wit != NULL) return NULL; // Too many witnesses. | |
1282 methodOop fm = wf.found_method(0); // Will be NULL if num_parts == 0. | |
1283 if (Dependencies::is_concrete_method(m)) { | |
1284 if (fm == NULL) { | |
1285 // It turns out that m was always the only implementation. | |
1286 fm = m; | |
1287 } else if (fm != m) { | |
1288 // Two conflicting implementations after all. | |
1289 // (This can happen if m is inherited into ctxk and fm overrides it.) | |
1290 return NULL; | |
1291 } | |
1292 } | |
1293 #ifndef PRODUCT | |
1294 // Make sure the dependency mechanism will pass this discovery: | |
1295 if (VerifyDependencies && fm != NULL) { | |
1296 guarantee(NULL == (void *)check_unique_concrete_method(ctxk, fm), | |
1297 "verify dep."); | |
1298 } | |
1299 #endif //PRODUCT | |
1300 return fm; | |
1301 } | |
1302 | |
1303 klassOop Dependencies::check_exclusive_concrete_methods(klassOop ctxk, | |
1304 methodOop m1, | |
1305 methodOop m2, | |
1306 DepChange* changes) { | |
1307 ClassHierarchyWalker wf(m1); | |
1308 wf.add_participant(m1->method_holder()); | |
1309 wf.add_participant(m2->method_holder()); | |
1310 return wf.find_witness_definer(ctxk, changes); | |
1311 } | |
1312 | |
1313 // Find the set of all non-abstract methods under ctxk that match m[0]. | |
1314 // (The method m[0] must be defined or inherited in ctxk.) | |
1315 // Include m itself in the set, unless it is abstract. | |
1316 // Fill the given array m[0..(mlen-1)] with this set, and return the length. | |
1317 // (The length may be zero if no concrete methods are found anywhere.) | |
1318 // If there are too many concrete methods to fit in marray, return -1. | |
1319 int Dependencies::find_exclusive_concrete_methods(klassOop ctxk, | |
1320 int mlen, | |
1321 methodOop marray[]) { | |
1322 methodOop m0 = marray[0]; | |
1323 ClassHierarchyWalker wf(m0); | |
1324 assert(wf.check_method_context(ctxk, m0), "proper context"); | |
1325 wf.record_witnesses(mlen); | |
1326 bool participants_hide_witnesses = true; | |
1327 klassOop wit = wf.find_witness_definer(ctxk); | |
1328 if (wit != NULL) return -1; // Too many witnesses. | |
1329 int num = wf.num_participants(); | |
1330 assert(num <= mlen, "oob"); | |
1331 // Keep track of whether m is also part of the result set. | |
1332 int mfill = 0; | |
1333 assert(marray[mfill] == m0, "sanity"); | |
1334 if (Dependencies::is_concrete_method(m0)) | |
1335 mfill++; // keep m0 as marray[0], the first result | |
1336 for (int i = 0; i < num; i++) { | |
1337 methodOop fm = wf.found_method(i); | |
1338 if (fm == m0) continue; // Already put this guy in the list. | |
1339 if (mfill == mlen) { | |
1340 return -1; // Oops. Too many methods after all! | |
1341 } | |
1342 marray[mfill++] = fm; | |
1343 } | |
1344 #ifndef PRODUCT | |
1345 // Make sure the dependency mechanism will pass this discovery: | |
1346 if (VerifyDependencies) { | |
1347 // Turn off dependency tracing while actually testing deps. | |
1348 FlagSetting fs(TraceDependencies, false); | |
1349 switch (mfill) { | |
1350 case 1: | |
1351 guarantee(NULL == (void *)check_unique_concrete_method(ctxk, marray[0]), | |
1352 "verify dep."); | |
1353 break; | |
1354 case 2: | |
1355 guarantee(NULL == (void *) | |
1356 check_exclusive_concrete_methods(ctxk, marray[0], marray[1]), | |
1357 "verify dep."); | |
1358 break; | |
1359 default: | |
1360 ShouldNotReachHere(); // mlen > 2 yet supported | |
1361 } | |
1362 } | |
1363 #endif //PRODUCT | |
1364 return mfill; | |
1365 } | |
1366 | |
1367 | |
1368 klassOop Dependencies::check_has_no_finalizable_subclasses(klassOop ctxk, DepChange* changes) { | |
1369 Klass* search_at = ctxk->klass_part(); | |
1370 if (changes != NULL) | |
1371 search_at = changes->new_type()->klass_part(); // just look at the new bit | |
1372 Klass* result = find_finalizable_subclass(search_at); | |
1373 if (result == NULL) { | |
1374 return NULL; | |
1375 } | |
1376 return result->as_klassOop(); | |
1377 } | |
1378 | |
1379 | |
1380 klassOop Dependencies::DepStream::check_dependency_impl(DepChange* changes) { | |
1381 assert_locked_or_safepoint(Compile_lock); | |
1382 | |
1383 klassOop witness = NULL; | |
1384 switch (type()) { | |
1385 case evol_method: | |
1386 witness = check_evol_method(method_argument(0)); | |
1387 break; | |
1388 case leaf_type: | |
1389 witness = check_leaf_type(context_type()); | |
1390 break; | |
1391 case abstract_with_unique_concrete_subtype: | |
1392 witness = check_abstract_with_unique_concrete_subtype(context_type(), | |
1393 type_argument(1), | |
1394 changes); | |
1395 break; | |
1396 case abstract_with_no_concrete_subtype: | |
1397 witness = check_abstract_with_no_concrete_subtype(context_type(), | |
1398 changes); | |
1399 break; | |
1400 case concrete_with_no_concrete_subtype: | |
1401 witness = check_concrete_with_no_concrete_subtype(context_type(), | |
1402 changes); | |
1403 break; | |
1404 case unique_concrete_method: | |
1405 witness = check_unique_concrete_method(context_type(), | |
1406 method_argument(1), | |
1407 changes); | |
1408 break; | |
1409 case abstract_with_exclusive_concrete_subtypes_2: | |
1410 witness = check_abstract_with_exclusive_concrete_subtypes(context_type(), | |
1411 type_argument(1), | |
1412 type_argument(2), | |
1413 changes); | |
1414 break; | |
1415 case exclusive_concrete_methods_2: | |
1416 witness = check_exclusive_concrete_methods(context_type(), | |
1417 method_argument(1), | |
1418 method_argument(2), | |
1419 changes); | |
1420 break; | |
1421 case no_finalizable_subclasses: | |
1422 witness = check_has_no_finalizable_subclasses(context_type(), | |
1423 changes); | |
1424 break; | |
1425 default: | |
1426 witness = NULL; | |
1427 ShouldNotReachHere(); | |
1428 break; | |
1429 } | |
1430 if (witness != NULL) { | |
1431 if (TraceDependencies) { | |
1432 print_dependency(witness, /*verbose=*/ true); | |
1433 } | |
1434 // The following is a no-op unless logging is enabled: | |
1435 log_dependency(witness); | |
1436 } | |
1437 return witness; | |
1438 } | |
1439 | |
1440 | |
1441 klassOop Dependencies::DepStream::spot_check_dependency_at(DepChange& changes) { | |
1442 if (!changes.involves_context(context_type())) | |
1443 // irrelevant dependency; skip it | |
1444 return NULL; | |
1445 | |
1446 return check_dependency_impl(&changes); | |
1447 } | |
1448 | |
1449 | |
1450 void DepChange::initialize() { | |
1451 // entire transaction must be under this lock: | |
1452 assert_lock_strong(Compile_lock); | |
1453 | |
1454 // Mark all dependee and all its superclasses | |
1455 // Mark transitive interfaces | |
1456 for (ContextStream str(*this); str.next(); ) { | |
1457 klassOop d = str.klass(); | |
1458 assert(!instanceKlass::cast(d)->is_marked_dependent(), "checking"); | |
1459 instanceKlass::cast(d)->set_is_marked_dependent(true); | |
1460 } | |
1461 } | |
1462 | |
1463 DepChange::~DepChange() { | |
1464 // Unmark all dependee and all its superclasses | |
1465 // Unmark transitive interfaces | |
1466 for (ContextStream str(*this); str.next(); ) { | |
1467 klassOop d = str.klass(); | |
1468 instanceKlass::cast(d)->set_is_marked_dependent(false); | |
1469 } | |
1470 } | |
1471 | |
1472 bool DepChange::involves_context(klassOop k) { | |
1473 if (k == NULL || !Klass::cast(k)->oop_is_instance()) { | |
1474 return false; | |
1475 } | |
1476 instanceKlass* ik = instanceKlass::cast(k); | |
1477 bool is_contained = ik->is_marked_dependent(); | |
1478 assert(is_contained == Klass::cast(new_type())->is_subtype_of(k), | |
1479 "correct marking of potential context types"); | |
1480 return is_contained; | |
1481 } | |
1482 | |
1483 bool DepChange::ContextStream::next() { | |
1484 switch (_change_type) { | |
1485 case Start_Klass: // initial state; _klass is the new type | |
1486 _ti_base = instanceKlass::cast(_klass)->transitive_interfaces(); | |
1487 _ti_index = 0; | |
1488 _change_type = Change_new_type; | |
1489 return true; | |
1490 case Change_new_type: | |
1491 // fall through: | |
1492 _change_type = Change_new_sub; | |
1493 case Change_new_sub: | |
1494 _klass = instanceKlass::cast(_klass)->super(); | |
1495 if (_klass != NULL) { | |
1496 return true; | |
1497 } | |
1498 // else set up _ti_limit and fall through: | |
1499 _ti_limit = (_ti_base == NULL) ? 0 : _ti_base->length(); | |
1500 _change_type = Change_new_impl; | |
1501 case Change_new_impl: | |
1502 if (_ti_index < _ti_limit) { | |
1503 _klass = klassOop( _ti_base->obj_at(_ti_index++) ); | |
1504 return true; | |
1505 } | |
1506 // fall through: | |
1507 _change_type = NO_CHANGE; // iterator is exhausted | |
1508 case NO_CHANGE: | |
1509 break; | |
1510 default: | |
1511 ShouldNotReachHere(); | |
1512 } | |
1513 return false; | |
1514 } | |
1515 | |
1516 void DepChange::print() { | |
1517 int nsup = 0, nint = 0; | |
1518 for (ContextStream str(*this); str.next(); ) { | |
1519 klassOop k = str.klass(); | |
1520 switch (str._change_type) { | |
1521 case Change_new_type: | |
1522 tty->print_cr(" dependee = %s", instanceKlass::cast(k)->external_name()); | |
1523 break; | |
1524 case Change_new_sub: | |
1525 if (!WizardMode) | |
1526 ++nsup; | |
1527 else tty->print_cr(" context super = %s", instanceKlass::cast(k)->external_name()); | |
1528 break; | |
1529 case Change_new_impl: | |
1530 if (!WizardMode) | |
1531 ++nint; | |
1532 else tty->print_cr(" context interface = %s", instanceKlass::cast(k)->external_name()); | |
1533 break; | |
1534 } | |
1535 } | |
1536 if (nsup + nint != 0) { | |
1537 tty->print_cr(" context supers = %d, interfaces = %d", nsup, nint); | |
1538 } | |
1539 } | |
1540 | |
1541 #ifndef PRODUCT | |
1542 void Dependencies::print_statistics() { | |
1543 if (deps_find_witness_print != 0) { | |
1544 // Call one final time, to flush out the data. | |
1545 deps_find_witness_print = -1; | |
1546 count_find_witness_calls(); | |
1547 } | |
1548 } | |
1549 #endif |