1 /*
2 * Copyright (c) 2005, 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 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/ciArrayKlass.hpp"
27 #include "ci/ciEnv.hpp"
28 #include "ci/ciKlass.hpp"
29 #include "ci/ciMethod.hpp"
30 #include "classfile/javaClasses.inline.hpp"
31 #include "code/dependencies.hpp"
32 #include "compiler/compileLog.hpp"
33 #include "compiler/compileBroker.hpp"
34 #include "compiler/compileTask.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "oops/klass.hpp"
37 #include "oops/oop.inline.hpp"
38 #include "oops/objArrayKlass.hpp"
39 #include "runtime/flags/flagSetting.hpp"
40 #include "runtime/handles.hpp"
41 #include "runtime/handles.inline.hpp"
42 #include "runtime/jniHandles.inline.hpp"
43 #include "runtime/thread.inline.hpp"
44 #include "utilities/copy.hpp"
45
46
47 #ifdef ASSERT
48 static bool must_be_in_vm() {
49 Thread* thread = Thread::current();
50 if (thread->is_Java_thread())
51 return ((JavaThread*)thread)->thread_state() == _thread_in_vm;
52 else
53 return true; //something like this: thread->is_VM_thread();
54 }
55 #endif //ASSERT
56
57 void Dependencies::initialize(ciEnv* env) {
58 Arena* arena = env->arena();
59 _oop_recorder = env->oop_recorder();
60 _log = env->log();
61 _dep_seen = new(arena) GrowableArray<int>(arena, 500, 0, 0);
62 #if INCLUDE_JVMCI
63 _using_dep_values = false;
64 #endif
65 DEBUG_ONLY(_deps[end_marker] = NULL);
66 for (int i = (int)FIRST_TYPE; i < (int)TYPE_LIMIT; i++) {
67 _deps[i] = new(arena) GrowableArray<ciBaseObject*>(arena, 10, 0, 0);
68 }
69 _content_bytes = NULL;
70 _size_in_bytes = (size_t)-1;
71
72 assert(TYPE_LIMIT <= (1<<LG2_TYPE_LIMIT), "sanity");
73 }
74
75 void Dependencies::assert_evol_method(ciMethod* m) {
76 assert_common_1(evol_method, m);
77 }
78
79 void Dependencies::assert_leaf_type(ciKlass* ctxk) {
80 if (ctxk->is_array_klass()) {
81 // As a special case, support this assertion on an array type,
82 // which reduces to an assertion on its element type.
83 // Note that this cannot be done with assertions that
84 // relate to concreteness or abstractness.
85 ciType* elemt = ctxk->as_array_klass()->base_element_type();
86 if (!elemt->is_instance_klass()) return; // Ex: int[][]
87 ctxk = elemt->as_instance_klass();
88 //if (ctxk->is_final()) return; // Ex: String[][]
89 }
90 check_ctxk(ctxk);
91 assert_common_1(leaf_type, ctxk);
92 }
93
94 void Dependencies::assert_abstract_with_unique_concrete_subtype(ciKlass* ctxk, ciKlass* conck) {
95 check_ctxk_abstract(ctxk);
96 assert_common_2(abstract_with_unique_concrete_subtype, ctxk, conck);
97 }
98
99 void Dependencies::assert_abstract_with_no_concrete_subtype(ciKlass* ctxk) {
100 check_ctxk_abstract(ctxk);
101 assert_common_1(abstract_with_no_concrete_subtype, ctxk);
102 }
103
104 void Dependencies::assert_concrete_with_no_concrete_subtype(ciKlass* ctxk) {
105 check_ctxk_concrete(ctxk);
106 assert_common_1(concrete_with_no_concrete_subtype, ctxk);
107 }
108
109 void Dependencies::assert_unique_concrete_method(ciKlass* ctxk, ciMethod* uniqm) {
110 check_ctxk(ctxk);
111 assert_common_2(unique_concrete_method, ctxk, uniqm);
112 }
113
114 void Dependencies::assert_abstract_with_exclusive_concrete_subtypes(ciKlass* ctxk, ciKlass* k1, ciKlass* k2) {
115 check_ctxk(ctxk);
116 assert_common_3(abstract_with_exclusive_concrete_subtypes_2, ctxk, k1, k2);
117 }
118
119 void Dependencies::assert_exclusive_concrete_methods(ciKlass* ctxk, ciMethod* m1, ciMethod* m2) {
120 check_ctxk(ctxk);
121 assert_common_3(exclusive_concrete_methods_2, ctxk, m1, m2);
122 }
123
124 void Dependencies::assert_has_no_finalizable_subclasses(ciKlass* ctxk) {
125 check_ctxk(ctxk);
126 assert_common_1(no_finalizable_subclasses, ctxk);
127 }
128
129 void Dependencies::assert_call_site_target_value(ciCallSite* call_site, ciMethodHandle* method_handle) {
130 assert_common_2(call_site_target_value, call_site, method_handle);
131 }
132
133 #if INCLUDE_JVMCI
134
135 Dependencies::Dependencies(Arena* arena, OopRecorder* oop_recorder, CompileLog* log) {
136 _oop_recorder = oop_recorder;
137 _log = log;
138 _dep_seen = new(arena) GrowableArray<int>(arena, 500, 0, 0);
139 _using_dep_values = true;
140 DEBUG_ONLY(_dep_values[end_marker] = NULL);
141 for (int i = (int)FIRST_TYPE; i < (int)TYPE_LIMIT; i++) {
142 _dep_values[i] = new(arena) GrowableArray<DepValue>(arena, 10, 0, DepValue());
143 }
144 _content_bytes = NULL;
145 _size_in_bytes = (size_t)-1;
146
147 assert(TYPE_LIMIT <= (1<<LG2_TYPE_LIMIT), "sanity");
148 }
149
150 void Dependencies::assert_evol_method(Method* m) {
151 assert_common_1(evol_method, DepValue(_oop_recorder, m));
152 }
153
154 void Dependencies::assert_has_no_finalizable_subclasses(Klass* ctxk) {
155 check_ctxk(ctxk);
156 assert_common_1(no_finalizable_subclasses, DepValue(_oop_recorder, ctxk));
157 }
158
159 void Dependencies::assert_leaf_type(Klass* ctxk) {
160 if (ctxk->is_array_klass()) {
161 // As a special case, support this assertion on an array type,
162 // which reduces to an assertion on its element type.
163 // Note that this cannot be done with assertions that
164 // relate to concreteness or abstractness.
165 BasicType elemt = ArrayKlass::cast(ctxk)->element_type();
166 if (is_java_primitive(elemt)) return; // Ex: int[][]
167 ctxk = ObjArrayKlass::cast(ctxk)->bottom_klass();
168 //if (ctxk->is_final()) return; // Ex: String[][]
169 }
170 check_ctxk(ctxk);
171 assert_common_1(leaf_type, DepValue(_oop_recorder, ctxk));
172 }
173
174 void Dependencies::assert_abstract_with_unique_concrete_subtype(Klass* ctxk, Klass* conck) {
175 check_ctxk_abstract(ctxk);
176 DepValue ctxk_dv(_oop_recorder, ctxk);
177 DepValue conck_dv(_oop_recorder, conck, &ctxk_dv);
178 assert_common_2(abstract_with_unique_concrete_subtype, ctxk_dv, conck_dv);
179 }
180
181 void Dependencies::assert_unique_concrete_method(Klass* ctxk, Method* uniqm) {
182 check_ctxk(ctxk);
183 assert_common_2(unique_concrete_method, DepValue(_oop_recorder, ctxk), DepValue(_oop_recorder, uniqm));
184 }
185
186 void Dependencies::assert_call_site_target_value(oop call_site, oop method_handle) {
187 assert_common_2(call_site_target_value, DepValue(_oop_recorder, JNIHandles::make_local(call_site)), DepValue(_oop_recorder, JNIHandles::make_local(method_handle)));
188 }
189
190 #endif // INCLUDE_JVMCI
191
192
193 // Helper function. If we are adding a new dep. under ctxk2,
194 // try to find an old dep. under a broader* ctxk1. If there is
195 //
196 bool Dependencies::maybe_merge_ctxk(GrowableArray<ciBaseObject*>* deps,
197 int ctxk_i, ciKlass* ctxk2) {
198 ciKlass* ctxk1 = deps->at(ctxk_i)->as_metadata()->as_klass();
199 if (ctxk2->is_subtype_of(ctxk1)) {
200 return true; // success, and no need to change
201 } else if (ctxk1->is_subtype_of(ctxk2)) {
202 // new context class fully subsumes previous one
203 deps->at_put(ctxk_i, ctxk2);
204 return true;
205 } else {
206 return false;
207 }
208 }
209
210 void Dependencies::assert_common_1(DepType dept, ciBaseObject* x) {
211 assert(dep_args(dept) == 1, "sanity");
212 log_dependency(dept, x);
213 GrowableArray<ciBaseObject*>* deps = _deps[dept];
214
215 // see if the same (or a similar) dep is already recorded
216 if (note_dep_seen(dept, x)) {
217 assert(deps->find(x) >= 0, "sanity");
218 } else {
219 deps->append(x);
220 }
221 }
222
223 void Dependencies::assert_common_2(DepType dept,
224 ciBaseObject* x0, ciBaseObject* x1) {
225 assert(dep_args(dept) == 2, "sanity");
226 log_dependency(dept, x0, x1);
227 GrowableArray<ciBaseObject*>* deps = _deps[dept];
228
229 // see if the same (or a similar) dep is already recorded
230 bool has_ctxk = has_explicit_context_arg(dept);
231 if (has_ctxk) {
232 assert(dep_context_arg(dept) == 0, "sanity");
233 if (note_dep_seen(dept, x1)) {
234 // look in this bucket for redundant assertions
235 const int stride = 2;
236 for (int i = deps->length(); (i -= stride) >= 0; ) {
237 ciBaseObject* y1 = deps->at(i+1);
238 if (x1 == y1) { // same subject; check the context
239 if (maybe_merge_ctxk(deps, i+0, x0->as_metadata()->as_klass())) {
240 return;
241 }
242 }
243 }
244 }
245 } else {
246 if (note_dep_seen(dept, x0) && note_dep_seen(dept, x1)) {
247 // look in this bucket for redundant assertions
248 const int stride = 2;
249 for (int i = deps->length(); (i -= stride) >= 0; ) {
250 ciBaseObject* y0 = deps->at(i+0);
251 ciBaseObject* y1 = deps->at(i+1);
252 if (x0 == y0 && x1 == y1) {
253 return;
254 }
255 }
256 }
257 }
258
259 // append the assertion in the correct bucket:
260 deps->append(x0);
261 deps->append(x1);
262 }
263
264 void Dependencies::assert_common_3(DepType dept,
265 ciKlass* ctxk, ciBaseObject* x, ciBaseObject* x2) {
266 assert(dep_context_arg(dept) == 0, "sanity");
267 assert(dep_args(dept) == 3, "sanity");
268 log_dependency(dept, ctxk, x, x2);
269 GrowableArray<ciBaseObject*>* deps = _deps[dept];
270
271 // try to normalize an unordered pair:
272 bool swap = false;
273 switch (dept) {
274 case abstract_with_exclusive_concrete_subtypes_2:
275 swap = (x->ident() > x2->ident() && x->as_metadata()->as_klass() != ctxk);
276 break;
277 case exclusive_concrete_methods_2:
278 swap = (x->ident() > x2->ident() && x->as_metadata()->as_method()->holder() != ctxk);
279 break;
280 default:
281 break;
282 }
283 if (swap) { ciBaseObject* t = x; x = x2; x2 = t; }
284
285 // see if the same (or a similar) dep is already recorded
286 if (note_dep_seen(dept, x) && note_dep_seen(dept, x2)) {
287 // look in this bucket for redundant assertions
288 const int stride = 3;
289 for (int i = deps->length(); (i -= stride) >= 0; ) {
290 ciBaseObject* y = deps->at(i+1);
291 ciBaseObject* y2 = deps->at(i+2);
292 if (x == y && x2 == y2) { // same subjects; check the context
293 if (maybe_merge_ctxk(deps, i+0, ctxk)) {
294 return;
295 }
296 }
297 }
298 }
299 // append the assertion in the correct bucket:
300 deps->append(ctxk);
301 deps->append(x);
302 deps->append(x2);
303 }
304
305 #if INCLUDE_JVMCI
306 bool Dependencies::maybe_merge_ctxk(GrowableArray<DepValue>* deps,
307 int ctxk_i, DepValue ctxk2_dv) {
308 Klass* ctxk1 = deps->at(ctxk_i).as_klass(_oop_recorder);
309 Klass* ctxk2 = ctxk2_dv.as_klass(_oop_recorder);
310 if (ctxk2->is_subtype_of(ctxk1)) {
311 return true; // success, and no need to change
312 } else if (ctxk1->is_subtype_of(ctxk2)) {
313 // new context class fully subsumes previous one
314 deps->at_put(ctxk_i, ctxk2_dv);
315 return true;
316 } else {
317 return false;
318 }
319 }
320
321 void Dependencies::assert_common_1(DepType dept, DepValue x) {
322 assert(dep_args(dept) == 1, "sanity");
323 //log_dependency(dept, x);
324 GrowableArray<DepValue>* deps = _dep_values[dept];
325
326 // see if the same (or a similar) dep is already recorded
327 if (note_dep_seen(dept, x)) {
328 assert(deps->find(x) >= 0, "sanity");
329 } else {
330 deps->append(x);
331 }
332 }
333
334 void Dependencies::assert_common_2(DepType dept,
335 DepValue x0, DepValue x1) {
336 assert(dep_args(dept) == 2, "sanity");
337 //log_dependency(dept, x0, x1);
338 GrowableArray<DepValue>* deps = _dep_values[dept];
339
340 // see if the same (or a similar) dep is already recorded
341 bool has_ctxk = has_explicit_context_arg(dept);
342 if (has_ctxk) {
343 assert(dep_context_arg(dept) == 0, "sanity");
344 if (note_dep_seen(dept, x1)) {
345 // look in this bucket for redundant assertions
346 const int stride = 2;
347 for (int i = deps->length(); (i -= stride) >= 0; ) {
348 DepValue y1 = deps->at(i+1);
349 if (x1 == y1) { // same subject; check the context
350 if (maybe_merge_ctxk(deps, i+0, x0)) {
351 return;
352 }
353 }
354 }
355 }
356 } else {
357 if (note_dep_seen(dept, x0) && note_dep_seen(dept, x1)) {
358 // look in this bucket for redundant assertions
359 const int stride = 2;
360 for (int i = deps->length(); (i -= stride) >= 0; ) {
361 DepValue y0 = deps->at(i+0);
362 DepValue y1 = deps->at(i+1);
363 if (x0 == y0 && x1 == y1) {
364 return;
365 }
366 }
367 }
368 }
369
370 // append the assertion in the correct bucket:
371 deps->append(x0);
372 deps->append(x1);
373 }
374 #endif // INCLUDE_JVMCI
375
376 /// Support for encoding dependencies into an nmethod:
377
378 void Dependencies::copy_to(nmethod* nm) {
379 address beg = nm->dependencies_begin();
380 address end = nm->dependencies_end();
381 guarantee(end - beg >= (ptrdiff_t) size_in_bytes(), "bad sizing");
382 Copy::disjoint_words((HeapWord*) content_bytes(),
383 (HeapWord*) beg,
384 size_in_bytes() / sizeof(HeapWord));
385 assert(size_in_bytes() % sizeof(HeapWord) == 0, "copy by words");
386 }
387
388 static int sort_dep(ciBaseObject** p1, ciBaseObject** p2, int narg) {
389 for (int i = 0; i < narg; i++) {
390 int diff = p1[i]->ident() - p2[i]->ident();
391 if (diff != 0) return diff;
392 }
393 return 0;
394 }
395 static int sort_dep_arg_1(ciBaseObject** p1, ciBaseObject** p2)
396 { return sort_dep(p1, p2, 1); }
397 static int sort_dep_arg_2(ciBaseObject** p1, ciBaseObject** p2)
398 { return sort_dep(p1, p2, 2); }
399 static int sort_dep_arg_3(ciBaseObject** p1, ciBaseObject** p2)
400 { return sort_dep(p1, p2, 3); }
401
402 #if INCLUDE_JVMCI
403 // metadata deps are sorted before object deps
404 static int sort_dep_value(Dependencies::DepValue* p1, Dependencies::DepValue* p2, int narg) {
405 for (int i = 0; i < narg; i++) {
406 int diff = p1[i].sort_key() - p2[i].sort_key();
407 if (diff != 0) return diff;
408 }
409 return 0;
410 }
411 static int sort_dep_value_arg_1(Dependencies::DepValue* p1, Dependencies::DepValue* p2)
412 { return sort_dep_value(p1, p2, 1); }
413 static int sort_dep_value_arg_2(Dependencies::DepValue* p1, Dependencies::DepValue* p2)
414 { return sort_dep_value(p1, p2, 2); }
415 static int sort_dep_value_arg_3(Dependencies::DepValue* p1, Dependencies::DepValue* p2)
416 { return sort_dep_value(p1, p2, 3); }
417 #endif // INCLUDE_JVMCI
418
419 void Dependencies::sort_all_deps() {
420 #if INCLUDE_JVMCI
421 if (_using_dep_values) {
422 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
423 DepType dept = (DepType)deptv;
424 GrowableArray<DepValue>* deps = _dep_values[dept];
425 if (deps->length() <= 1) continue;
426 switch (dep_args(dept)) {
427 case 1: deps->sort(sort_dep_value_arg_1, 1); break;
428 case 2: deps->sort(sort_dep_value_arg_2, 2); break;
429 case 3: deps->sort(sort_dep_value_arg_3, 3); break;
430 default: ShouldNotReachHere(); break;
431 }
432 }
433 return;
434 }
435 #endif // INCLUDE_JVMCI
436 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
437 DepType dept = (DepType)deptv;
438 GrowableArray<ciBaseObject*>* deps = _deps[dept];
439 if (deps->length() <= 1) continue;
440 switch (dep_args(dept)) {
441 case 1: deps->sort(sort_dep_arg_1, 1); break;
442 case 2: deps->sort(sort_dep_arg_2, 2); break;
443 case 3: deps->sort(sort_dep_arg_3, 3); break;
444 default: ShouldNotReachHere(); break;
445 }
446 }
447 }
448
449 size_t Dependencies::estimate_size_in_bytes() {
450 size_t est_size = 100;
451 #if INCLUDE_JVMCI
452 if (_using_dep_values) {
453 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
454 DepType dept = (DepType)deptv;
455 GrowableArray<DepValue>* deps = _dep_values[dept];
456 est_size += deps->length() * 2; // tags and argument(s)
457 }
458 return est_size;
459 }
460 #endif // INCLUDE_JVMCI
461 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
462 DepType dept = (DepType)deptv;
463 GrowableArray<ciBaseObject*>* deps = _deps[dept];
464 est_size += deps->length()*2; // tags and argument(s)
465 }
466 return est_size;
467 }
468
469 ciKlass* Dependencies::ctxk_encoded_as_null(DepType dept, ciBaseObject* x) {
470 switch (dept) {
471 case abstract_with_exclusive_concrete_subtypes_2:
472 return x->as_metadata()->as_klass();
473 case unique_concrete_method:
474 case exclusive_concrete_methods_2:
475 return x->as_metadata()->as_method()->holder();
476 default:
477 return NULL; // let NULL be NULL
478 }
479 }
480
481 Klass* Dependencies::ctxk_encoded_as_null(DepType dept, Metadata* x) {
482 assert(must_be_in_vm(), "raw oops here");
483 switch (dept) {
484 case abstract_with_exclusive_concrete_subtypes_2:
485 assert(x->is_klass(), "sanity");
486 return (Klass*) x;
487 case unique_concrete_method:
488 case exclusive_concrete_methods_2:
489 assert(x->is_method(), "sanity");
490 return ((Method*)x)->method_holder();
491 default:
492 return NULL; // let NULL be NULL
493 }
494 }
495
496 void Dependencies::encode_content_bytes() {
497 sort_all_deps();
498
499 // cast is safe, no deps can overflow INT_MAX
500 CompressedWriteStream bytes((int)estimate_size_in_bytes());
501
502 #if INCLUDE_JVMCI
503 if (_using_dep_values) {
504 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
505 DepType dept = (DepType)deptv;
506 GrowableArray<DepValue>* deps = _dep_values[dept];
507 if (deps->length() == 0) continue;
508 int stride = dep_args(dept);
509 int ctxkj = dep_context_arg(dept); // -1 if no context arg
510 assert(stride > 0, "sanity");
511 for (int i = 0; i < deps->length(); i += stride) {
512 jbyte code_byte = (jbyte)dept;
513 int skipj = -1;
514 if (ctxkj >= 0 && ctxkj+1 < stride) {
515 Klass* ctxk = deps->at(i+ctxkj+0).as_klass(_oop_recorder);
516 DepValue x = deps->at(i+ctxkj+1); // following argument
517 if (ctxk == ctxk_encoded_as_null(dept, x.as_metadata(_oop_recorder))) {
518 skipj = ctxkj; // we win: maybe one less oop to keep track of
519 code_byte |= default_context_type_bit;
520 }
521 }
522 bytes.write_byte(code_byte);
523 for (int j = 0; j < stride; j++) {
524 if (j == skipj) continue;
525 DepValue v = deps->at(i+j);
526 int idx = v.index();
527 bytes.write_int(idx);
528 }
529 }
530 }
531 } else {
532 #endif // INCLUDE_JVMCI
533 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
534 DepType dept = (DepType)deptv;
535 GrowableArray<ciBaseObject*>* deps = _deps[dept];
536 if (deps->length() == 0) continue;
537 int stride = dep_args(dept);
538 int ctxkj = dep_context_arg(dept); // -1 if no context arg
539 assert(stride > 0, "sanity");
540 for (int i = 0; i < deps->length(); i += stride) {
541 jbyte code_byte = (jbyte)dept;
542 int skipj = -1;
543 if (ctxkj >= 0 && ctxkj+1 < stride) {
544 ciKlass* ctxk = deps->at(i+ctxkj+0)->as_metadata()->as_klass();
545 ciBaseObject* x = deps->at(i+ctxkj+1); // following argument
546 if (ctxk == ctxk_encoded_as_null(dept, x)) {
547 skipj = ctxkj; // we win: maybe one less oop to keep track of
548 code_byte |= default_context_type_bit;
549 }
550 }
551 bytes.write_byte(code_byte);
552 for (int j = 0; j < stride; j++) {
553 if (j == skipj) continue;
554 ciBaseObject* v = deps->at(i+j);
555 int idx;
556 if (v->is_object()) {
557 idx = _oop_recorder->find_index(v->as_object()->constant_encoding());
558 } else {
559 ciMetadata* meta = v->as_metadata();
560 idx = _oop_recorder->find_index(meta->constant_encoding());
561 }
562 bytes.write_int(idx);
563 }
564 }
565 }
566 #if INCLUDE_JVMCI
567 }
568 #endif
569
570 // write a sentinel byte to mark the end
571 bytes.write_byte(end_marker);
572
573 // round it out to a word boundary
574 while (bytes.position() % sizeof(HeapWord) != 0) {
575 bytes.write_byte(end_marker);
576 }
577
578 // check whether the dept byte encoding really works
579 assert((jbyte)default_context_type_bit != 0, "byte overflow");
580
581 _content_bytes = bytes.buffer();
582 _size_in_bytes = bytes.position();
583 }
584
585
586 const char* Dependencies::_dep_name[TYPE_LIMIT] = {
587 "end_marker",
588 "evol_method",
589 "leaf_type",
590 "abstract_with_unique_concrete_subtype",
591 "abstract_with_no_concrete_subtype",
592 "concrete_with_no_concrete_subtype",
593 "unique_concrete_method",
594 "abstract_with_exclusive_concrete_subtypes_2",
595 "exclusive_concrete_methods_2",
596 "no_finalizable_subclasses",
597 "call_site_target_value"
598 };
599
600 int Dependencies::_dep_args[TYPE_LIMIT] = {
601 -1,// end_marker
602 1, // evol_method m
603 1, // leaf_type ctxk
604 2, // abstract_with_unique_concrete_subtype ctxk, k
605 1, // abstract_with_no_concrete_subtype ctxk
606 1, // concrete_with_no_concrete_subtype ctxk
607 2, // unique_concrete_method ctxk, m
608 3, // unique_concrete_subtypes_2 ctxk, k1, k2
609 3, // unique_concrete_methods_2 ctxk, m1, m2
610 1, // no_finalizable_subclasses ctxk
611 2 // call_site_target_value call_site, method_handle
612 };
613
614 const char* Dependencies::dep_name(Dependencies::DepType dept) {
615 if (!dept_in_mask(dept, all_types)) return "?bad-dep?";
616 return _dep_name[dept];
617 }
618
619 int Dependencies::dep_args(Dependencies::DepType dept) {
620 if (!dept_in_mask(dept, all_types)) return -1;
621 return _dep_args[dept];
622 }
623
624 void Dependencies::check_valid_dependency_type(DepType dept) {
625 guarantee(FIRST_TYPE <= dept && dept < TYPE_LIMIT, "invalid dependency type: %d", (int) dept);
626 }
627
628 Dependencies::DepType Dependencies::validate_dependencies(CompileTask* task, bool counter_changed, char** failure_detail) {
629 // First, check non-klass dependencies as we might return early and
630 // not check klass dependencies if the system dictionary
631 // modification counter hasn't changed (see below).
632 for (Dependencies::DepStream deps(this); deps.next(); ) {
633 if (deps.is_klass_type()) continue; // skip klass dependencies
634 Klass* witness = deps.check_dependency();
635 if (witness != NULL) {
636 return deps.type();
637 }
638 }
639
640 // Klass dependencies must be checked when the system dictionary
641 // changes. If logging is enabled all violated dependences will be
642 // recorded in the log. In debug mode check dependencies even if
643 // the system dictionary hasn't changed to verify that no invalid
644 // dependencies were inserted. Any violated dependences in this
645 // case are dumped to the tty.
646 if (!counter_changed && !trueInDebug) {
647 return end_marker;
648 }
649
650 int klass_violations = 0;
651 DepType result = end_marker;
652 for (Dependencies::DepStream deps(this); deps.next(); ) {
653 if (!deps.is_klass_type()) continue; // skip non-klass dependencies
654 Klass* witness = deps.check_dependency();
655 if (witness != NULL) {
656 if (klass_violations == 0) {
657 result = deps.type();
658 if (failure_detail != NULL && klass_violations == 0) {
659 // Use a fixed size buffer to prevent the string stream from
660 // resizing in the context of an inner resource mark.
661 char* buffer = NEW_RESOURCE_ARRAY(char, O_BUFLEN);
662 stringStream st(buffer, O_BUFLEN);
663 deps.print_dependency(witness, true, &st);
664 *failure_detail = st.as_string();
665 }
666 }
667 klass_violations++;
668 if (!counter_changed) {
669 // Dependence failed but counter didn't change. Log a message
670 // describing what failed and allow the assert at the end to
671 // trigger.
672 deps.print_dependency(witness);
673 } else if (xtty == NULL) {
674 // If we're not logging then a single violation is sufficient,
675 // otherwise we want to log all the dependences which were
676 // violated.
677 break;
678 }
679 }
680 }
681
682 if (klass_violations != 0) {
683 #ifdef ASSERT
684 if (task != NULL && !counter_changed && !PrintCompilation) {
685 // Print out the compile task that failed
686 task->print_tty();
687 }
688 #endif
689 assert(counter_changed, "failed dependencies, but counter didn't change");
690 }
691 return result;
692 }
693
694 // for the sake of the compiler log, print out current dependencies:
695 void Dependencies::log_all_dependencies() {
696 if (log() == NULL) return;
697 ResourceMark rm;
698 for (int deptv = (int)FIRST_TYPE; deptv < (int)TYPE_LIMIT; deptv++) {
699 DepType dept = (DepType)deptv;
700 GrowableArray<ciBaseObject*>* deps = _deps[dept];
701 int deplen = deps->length();
702 if (deplen == 0) {
703 continue;
704 }
705 int stride = dep_args(dept);
706 GrowableArray<ciBaseObject*>* ciargs = new GrowableArray<ciBaseObject*>(stride);
707 for (int i = 0; i < deps->length(); i += stride) {
708 for (int j = 0; j < stride; j++) {
709 // flush out the identities before printing
710 ciargs->push(deps->at(i+j));
711 }
712 write_dependency_to(log(), dept, ciargs);
713 ciargs->clear();
714 }
715 guarantee(deplen == deps->length(), "deps array cannot grow inside nested ResoureMark scope");
716 }
717 }
718
719 void Dependencies::write_dependency_to(CompileLog* log,
720 DepType dept,
721 GrowableArray<DepArgument>* args,
722 Klass* witness) {
723 if (log == NULL) {
724 return;
725 }
726 ResourceMark rm;
727 ciEnv* env = ciEnv::current();
728 GrowableArray<ciBaseObject*>* ciargs = new GrowableArray<ciBaseObject*>(args->length());
729 for (GrowableArrayIterator<DepArgument> it = args->begin(); it != args->end(); ++it) {
730 DepArgument arg = *it;
731 if (arg.is_oop()) {
732 ciargs->push(env->get_object(arg.oop_value()));
733 } else {
734 ciargs->push(env->get_metadata(arg.metadata_value()));
735 }
736 }
737 int argslen = ciargs->length();
738 Dependencies::write_dependency_to(log, dept, ciargs, witness);
739 guarantee(argslen == ciargs->length(), "ciargs array cannot grow inside nested ResoureMark scope");
740 }
741
742 void Dependencies::write_dependency_to(CompileLog* log,
743 DepType dept,
744 GrowableArray<ciBaseObject*>* args,
745 Klass* witness) {
746 if (log == NULL) {
747 return;
748 }
749 ResourceMark rm;
750 GrowableArray<int>* argids = new GrowableArray<int>(args->length());
751 for (GrowableArrayIterator<ciBaseObject*> it = args->begin(); it != args->end(); ++it) {
752 ciBaseObject* obj = *it;
753 if (obj->is_object()) {
754 argids->push(log->identify(obj->as_object()));
755 } else {
756 argids->push(log->identify(obj->as_metadata()));
757 }
758 }
759 if (witness != NULL) {
760 log->begin_elem("dependency_failed");
761 } else {
762 log->begin_elem("dependency");
763 }
764 log->print(" type='%s'", dep_name(dept));
765 const int ctxkj = dep_context_arg(dept); // -1 if no context arg
766 if (ctxkj >= 0 && ctxkj < argids->length()) {
767 log->print(" ctxk='%d'", argids->at(ctxkj));
768 }
769 // write remaining arguments, if any.
770 for (int j = 0; j < argids->length(); j++) {
771 if (j == ctxkj) continue; // already logged
772 if (j == 1) {
773 log->print( " x='%d'", argids->at(j));
774 } else {
775 log->print(" x%d='%d'", j, argids->at(j));
776 }
777 }
778 if (witness != NULL) {
779 log->object("witness", witness);
780 log->stamp();
781 }
782 log->end_elem();
783 }
784
785 void Dependencies::write_dependency_to(xmlStream* xtty,
786 DepType dept,
787 GrowableArray<DepArgument>* args,
788 Klass* witness) {
789 if (xtty == NULL) {
790 return;
791 }
792 Thread* thread = Thread::current();
793 HandleMark rm(thread);
794 ttyLocker ttyl;
795 int ctxkj = dep_context_arg(dept); // -1 if no context arg
796 if (witness != NULL) {
797 xtty->begin_elem("dependency_failed");
798 } else {
799 xtty->begin_elem("dependency");
800 }
801 xtty->print(" type='%s'", dep_name(dept));
802 if (ctxkj >= 0) {
803 xtty->object("ctxk", args->at(ctxkj).metadata_value());
804 }
805 // write remaining arguments, if any.
806 for (int j = 0; j < args->length(); j++) {
807 if (j == ctxkj) continue; // already logged
808 DepArgument arg = args->at(j);
809 if (j == 1) {
810 if (arg.is_oop()) {
811 xtty->object("x", Handle(thread, arg.oop_value()));
812 } else {
813 xtty->object("x", arg.metadata_value());
814 }
815 } else {
816 char xn[12]; sprintf(xn, "x%d", j);
817 if (arg.is_oop()) {
818 xtty->object(xn, Handle(thread, arg.oop_value()));
819 } else {
820 xtty->object(xn, arg.metadata_value());
821 }
822 }
823 }
824 if (witness != NULL) {
825 xtty->object("witness", witness);
826 xtty->stamp();
827 }
828 xtty->end_elem();
829 }
830
831 void Dependencies::print_dependency(DepType dept, GrowableArray<DepArgument>* args,
832 Klass* witness, outputStream* st) {
833 ResourceMark rm;
834 ttyLocker ttyl; // keep the following output all in one block
835 st->print_cr("%s of type %s",
836 (witness == NULL)? "Dependency": "Failed dependency",
837 dep_name(dept));
838 // print arguments
839 int ctxkj = dep_context_arg(dept); // -1 if no context arg
840 for (int j = 0; j < args->length(); j++) {
841 DepArgument arg = args->at(j);
842 bool put_star = false;
843 if (arg.is_null()) continue;
844 const char* what;
845 if (j == ctxkj) {
846 assert(arg.is_metadata(), "must be");
847 what = "context";
848 put_star = !Dependencies::is_concrete_klass((Klass*)arg.metadata_value());
849 } else if (arg.is_method()) {
850 what = "method ";
851 put_star = !Dependencies::is_concrete_method((Method*)arg.metadata_value(), NULL);
852 } else if (arg.is_klass()) {
853 what = "class ";
854 } else {
855 what = "object ";
856 }
857 st->print(" %s = %s", what, (put_star? "*": ""));
858 if (arg.is_klass()) {
859 st->print("%s", ((Klass*)arg.metadata_value())->external_name());
860 } else if (arg.is_method()) {
861 ((Method*)arg.metadata_value())->print_value_on(st);
862 } else if (arg.is_oop()) {
863 arg.oop_value()->print_value_on(st);
864 } else {
865 ShouldNotReachHere(); // Provide impl for this type.
866 }
867
868 st->cr();
869 }
870 if (witness != NULL) {
871 bool put_star = !Dependencies::is_concrete_klass(witness);
872 st->print_cr(" witness = %s%s",
873 (put_star? "*": ""),
874 witness->external_name());
875 }
876 }
877
878 void Dependencies::DepStream::log_dependency(Klass* witness) {
879 if (_deps == NULL && xtty == NULL) return; // fast cutout for runtime
880 ResourceMark rm;
881 const int nargs = argument_count();
882 GrowableArray<DepArgument>* args = new GrowableArray<DepArgument>(nargs);
883 for (int j = 0; j < nargs; j++) {
884 if (is_oop_argument(j)) {
885 args->push(argument_oop(j));
886 } else {
887 args->push(argument(j));
888 }
889 }
890 int argslen = args->length();
891 if (_deps != NULL && _deps->log() != NULL) {
892 if (ciEnv::current() != NULL) {
893 Dependencies::write_dependency_to(_deps->log(), type(), args, witness);
894 } else {
895 // Treat the CompileLog as an xmlstream instead
896 Dependencies::write_dependency_to((xmlStream*)_deps->log(), type(), args, witness);
897 }
898 } else {
899 Dependencies::write_dependency_to(xtty, type(), args, witness);
900 }
901 guarantee(argslen == args->length(), "args array cannot grow inside nested ResoureMark scope");
902 }
903
904 void Dependencies::DepStream::print_dependency(Klass* witness, bool verbose, outputStream* st) {
905 ResourceMark rm;
906 int nargs = argument_count();
907 GrowableArray<DepArgument>* args = new GrowableArray<DepArgument>(nargs);
908 for (int j = 0; j < nargs; j++) {
909 if (is_oop_argument(j)) {
910 args->push(argument_oop(j));
911 } else {
912 args->push(argument(j));
913 }
914 }
915 int argslen = args->length();
916 Dependencies::print_dependency(type(), args, witness, st);
917 if (verbose) {
918 if (_code != NULL) {
919 st->print(" code: ");
920 _code->print_value_on(st);
921 st->cr();
922 }
923 }
924 guarantee(argslen == args->length(), "args array cannot grow inside nested ResoureMark scope");
925 }
926
927
928 /// Dependency stream support (decodes dependencies from an nmethod):
929
930 #ifdef ASSERT
931 void Dependencies::DepStream::initial_asserts(size_t byte_limit) {
932 assert(must_be_in_vm(), "raw oops here");
933 _byte_limit = byte_limit;
934 _type = (DepType)(end_marker-1); // defeat "already at end" assert
935 assert((_code!=NULL) + (_deps!=NULL) == 1, "one or t'other");
936 }
937 #endif //ASSERT
938
939 bool Dependencies::DepStream::next() {
940 assert(_type != end_marker, "already at end");
941 if (_bytes.position() == 0 && _code != NULL
942 && _code->dependencies_size() == 0) {
943 // Method has no dependencies at all.
944 return false;
945 }
946 int code_byte = (_bytes.read_byte() & 0xFF);
947 if (code_byte == end_marker) {
948 DEBUG_ONLY(_type = end_marker);
949 return false;
950 } else {
951 int ctxk_bit = (code_byte & Dependencies::default_context_type_bit);
952 code_byte -= ctxk_bit;
953 DepType dept = (DepType)code_byte;
954 _type = dept;
955 Dependencies::check_valid_dependency_type(dept);
956 int stride = _dep_args[dept];
957 assert(stride == dep_args(dept), "sanity");
958 int skipj = -1;
959 if (ctxk_bit != 0) {
960 skipj = 0; // currently the only context argument is at zero
961 assert(skipj == dep_context_arg(dept), "zero arg always ctxk");
962 }
963 for (int j = 0; j < stride; j++) {
964 _xi[j] = (j == skipj)? 0: _bytes.read_int();
965 }
966 DEBUG_ONLY(_xi[stride] = -1); // help detect overruns
967 return true;
968 }
969 }
970
971 inline Metadata* Dependencies::DepStream::recorded_metadata_at(int i) {
972 Metadata* o = NULL;
973 if (_code != NULL) {
974 o = _code->metadata_at(i);
975 } else {
976 o = _deps->oop_recorder()->metadata_at(i);
977 }
978 return o;
979 }
980
981 inline oop Dependencies::DepStream::recorded_oop_at(int i) {
982 return (_code != NULL)
983 ? _code->oop_at(i)
984 : JNIHandles::resolve(_deps->oop_recorder()->oop_at(i));
985 }
986
987 Metadata* Dependencies::DepStream::argument(int i) {
988 Metadata* result = recorded_metadata_at(argument_index(i));
989
990 if (result == NULL) { // Explicit context argument can be compressed
991 int ctxkj = dep_context_arg(type()); // -1 if no explicit context arg
992 if (ctxkj >= 0 && i == ctxkj && ctxkj+1 < argument_count()) {
993 result = ctxk_encoded_as_null(type(), argument(ctxkj+1));
994 }
995 }
996
997 assert(result == NULL || result->is_klass() || result->is_method(), "must be");
998 return result;
999 }
1000
1001 /**
1002 * Returns a unique identifier for each dependency argument.
1003 */
1004 uintptr_t Dependencies::DepStream::get_identifier(int i) {
1005 if (is_oop_argument(i)) {
1006 return (uintptr_t)(oopDesc*)argument_oop(i);
1007 } else {
1008 return (uintptr_t)argument(i);
1009 }
1010 }
1011
1012 oop Dependencies::DepStream::argument_oop(int i) {
1013 oop result = recorded_oop_at(argument_index(i));
1014 assert(oopDesc::is_oop_or_null(result), "must be");
1015 return result;
1016 }
1017
1018 Klass* Dependencies::DepStream::context_type() {
1019 assert(must_be_in_vm(), "raw oops here");
1020
1021 // Most dependencies have an explicit context type argument.
1022 {
1023 int ctxkj = dep_context_arg(type()); // -1 if no explicit context arg
1024 if (ctxkj >= 0) {
1025 Metadata* k = argument(ctxkj);
1026 assert(k != NULL && k->is_klass(), "type check");
1027 return (Klass*)k;
1028 }
1029 }
1030
1031 // Some dependencies are using the klass of the first object
1032 // argument as implicit context type.
1033 {
1034 int ctxkj = dep_implicit_context_arg(type());
1035 if (ctxkj >= 0) {
1036 Klass* k = argument_oop(ctxkj)->klass();
1037 assert(k != NULL && k->is_klass(), "type check");
1038 return (Klass*) k;
1039 }
1040 }
1041
1042 // And some dependencies don't have a context type at all,
1043 // e.g. evol_method.
1044 return NULL;
1045 }
1046
1047 // ----------------- DependencySignature --------------------------------------
1048 bool DependencySignature::equals(DependencySignature const& s1, DependencySignature const& s2) {
1049 if ((s1.type() != s2.type()) || (s1.args_count() != s2.args_count())) {
1050 return false;
1051 }
1052
1053 for (int i = 0; i < s1.args_count(); i++) {
1054 if (s1.arg(i) != s2.arg(i)) {
1055 return false;
1056 }
1057 }
1058 return true;
1059 }
1060
1061 /// Checking dependencies:
1062
1063 // This hierarchy walker inspects subtypes of a given type,
1064 // trying to find a "bad" class which breaks a dependency.
1065 // Such a class is called a "witness" to the broken dependency.
1066 // While searching around, we ignore "participants", which
1067 // are already known to the dependency.
1068 class ClassHierarchyWalker {
1069 public:
1070 enum { PARTICIPANT_LIMIT = 3 };
1071
1072 private:
1073 // optional method descriptor to check for:
1074 Symbol* _name;
1075 Symbol* _signature;
1076
1077 // special classes which are not allowed to be witnesses:
1078 Klass* _participants[PARTICIPANT_LIMIT+1];
1079 int _num_participants;
1080
1081 // cache of method lookups
1082 Method* _found_methods[PARTICIPANT_LIMIT+1];
1083
1084 // if non-zero, tells how many witnesses to convert to participants
1085 int _record_witnesses;
1086
1087 void initialize(Klass* participant) {
1088 _record_witnesses = 0;
1089 _participants[0] = participant;
1090 _found_methods[0] = NULL;
1091 _num_participants = 0;
1092 if (participant != NULL) {
1093 // Terminating NULL.
1094 _participants[1] = NULL;
1095 _found_methods[1] = NULL;
1096 _num_participants = 1;
1097 }
1098 }
1099
1100 void initialize_from_method(Method* m) {
1101 assert(m != NULL && m->is_method(), "sanity");
1102 _name = m->name();
1103 _signature = m->signature();
1104 }
1105
1106 public:
1107 // The walker is initialized to recognize certain methods and/or types
1108 // as friendly participants.
1109 ClassHierarchyWalker(Klass* participant, Method* m) {
1110 initialize_from_method(m);
1111 initialize(participant);
1112 }
1113 ClassHierarchyWalker(Method* m) {
1114 initialize_from_method(m);
1115 initialize(NULL);
1116 }
1117 ClassHierarchyWalker(Klass* participant = NULL) {
1118 _name = NULL;
1119 _signature = NULL;
1120 initialize(participant);
1121 }
1122 ClassHierarchyWalker(Klass* participants[], int num_participants) {
1123 _name = NULL;
1124 _signature = NULL;
1125 initialize(NULL);
1126 for (int i = 0; i < num_participants; ++i) {
1127 add_participant(participants[i]);
1128 }
1129 }
1130
1131 // This is common code for two searches: One for concrete subtypes,
1132 // the other for concrete method implementations and overrides.
1133 bool doing_subtype_search() {
1134 return _name == NULL;
1135 }
1136
1137 int num_participants() { return _num_participants; }
1138 Klass* participant(int n) {
1139 assert((uint)n <= (uint)_num_participants, "oob");
1140 return _participants[n];
1141 }
1142
1143 // Note: If n==num_participants, returns NULL.
1144 Method* found_method(int n) {
1145 assert((uint)n <= (uint)_num_participants, "oob");
1146 Method* fm = _found_methods[n];
1147 assert(n == _num_participants || fm != NULL, "proper usage");
1148 if (fm != NULL && fm->method_holder() != _participants[n]) {
1149 // Default methods from interfaces can be added to classes. In
1150 // that case the holder of the method is not the class but the
1151 // interface where it's defined.
1152 assert(fm->is_default_method(), "sanity");
1153 return NULL;
1154 }
1155 return fm;
1156 }
1157
1158 #ifdef ASSERT
1159 // Assert that m is inherited into ctxk, without intervening overrides.
1160 // (May return true even if this is not true, in corner cases where we punt.)
1161 bool check_method_context(Klass* ctxk, Method* m) {
1162 if (m->method_holder() == ctxk)
1163 return true; // Quick win.
1164 if (m->is_private())
1165 return false; // Quick lose. Should not happen.
1166 if (!(m->is_public() || m->is_protected()))
1167 // The override story is complex when packages get involved.
1168 return true; // Must punt the assertion to true.
1169 Method* lm = ctxk->lookup_method(m->name(), m->signature());
1170 if (lm == NULL && ctxk->is_instance_klass()) {
1171 // It might be an interface method
1172 lm = InstanceKlass::cast(ctxk)->lookup_method_in_ordered_interfaces(m->name(),
1173 m->signature());
1174 }
1175 if (lm == m)
1176 // Method m is inherited into ctxk.
1177 return true;
1178 if (lm != NULL) {
1179 if (!(lm->is_public() || lm->is_protected())) {
1180 // Method is [package-]private, so the override story is complex.
1181 return true; // Must punt the assertion to true.
1182 }
1183 if (lm->is_static()) {
1184 // Static methods don't override non-static so punt
1185 return true;
1186 }
1187 if (!Dependencies::is_concrete_method(lm, ctxk) &&
1188 !Dependencies::is_concrete_method(m, ctxk)) {
1189 // They are both non-concrete
1190 if (lm->method_holder()->is_subtype_of(m->method_holder())) {
1191 // Method m is overridden by lm, but both are non-concrete.
1192 return true;
1193 }
1194 if (lm->method_holder()->is_interface() && m->method_holder()->is_interface() &&
1195 ctxk->is_subtype_of(m->method_holder()) && ctxk->is_subtype_of(lm->method_holder())) {
1196 // Interface method defined in multiple super interfaces
1197 return true;
1198 }
1199 }
1200 }
1201 ResourceMark rm;
1202 tty->print_cr("Dependency method not found in the associated context:");
1203 tty->print_cr(" context = %s", ctxk->external_name());
1204 tty->print( " method = "); m->print_short_name(tty); tty->cr();
1205 if (lm != NULL) {
1206 tty->print( " found = "); lm->print_short_name(tty); tty->cr();
1207 }
1208 return false;
1209 }
1210 #endif
1211
1212 void add_participant(Klass* participant) {
1213 assert(_num_participants + _record_witnesses < PARTICIPANT_LIMIT, "oob");
1214 int np = _num_participants++;
1215 _participants[np] = participant;
1216 _participants[np+1] = NULL;
1217 _found_methods[np+1] = NULL;
1218 }
1219
1220 void record_witnesses(int add) {
1221 if (add > PARTICIPANT_LIMIT) add = PARTICIPANT_LIMIT;
1222 assert(_num_participants + add < PARTICIPANT_LIMIT, "oob");
1223 _record_witnesses = add;
1224 }
1225
1226 bool is_witness(Klass* k) {
1227 if (doing_subtype_search()) {
1228 return Dependencies::is_concrete_klass(k);
1229 } else if (!k->is_instance_klass()) {
1230 return false; // no methods to find in an array type
1231 } else {
1232 // Search class hierarchy first, skipping private implementations
1233 // as they never override any inherited methods
1234 Method* m = InstanceKlass::cast(k)->find_instance_method(_name, _signature, Klass::skip_private);
1235 if (!Dependencies::is_concrete_method(m, k)) {
1236 // Check for re-abstraction of method
1237 if (!k->is_interface() && m != NULL && m->is_abstract()) {
1238 // Found a matching abstract method 'm' in the class hierarchy.
1239 // This is fine iff 'k' is an abstract class and all concrete subtypes
1240 // of 'k' override 'm' and are participates of the current search.
1241 ClassHierarchyWalker wf(_participants, _num_participants);
1242 Klass* w = wf.find_witness_subtype(k);
1243 if (w != NULL) {
1244 Method* wm = InstanceKlass::cast(w)->find_instance_method(_name, _signature);
1245 if (!Dependencies::is_concrete_method(wm, w)) {
1246 // Found a concrete subtype 'w' which does not override abstract method 'm'.
1247 // Bail out because 'm' could be called with 'w' as receiver (leading to an
1248 // AbstractMethodError) and thus the method we are looking for is not unique.
1249 _found_methods[_num_participants] = m;
1250 return true;
1251 }
1252 }
1253 }
1254 // Check interface defaults also, if any exist.
1255 Array<Method*>* default_methods = InstanceKlass::cast(k)->default_methods();
1256 if (default_methods == NULL)
1257 return false;
1258 m = InstanceKlass::cast(k)->find_method(default_methods, _name, _signature);
1259 if (!Dependencies::is_concrete_method(m, NULL))
1260 return false;
1261 }
1262 _found_methods[_num_participants] = m;
1263 // Note: If add_participant(k) is called,
1264 // the method m will already be memoized for it.
1265 return true;
1266 }
1267 }
1268
1269 bool is_participant(Klass* k) {
1270 if (k == _participants[0]) {
1271 return true;
1272 } else if (_num_participants <= 1) {
1273 return false;
1274 } else {
1275 return in_list(k, &_participants[1]);
1276 }
1277 }
1278 bool ignore_witness(Klass* witness) {
1279 if (_record_witnesses == 0) {
1280 return false;
1281 } else {
1282 --_record_witnesses;
1283 add_participant(witness);
1284 return true;
1285 }
1286 }
1287 static bool in_list(Klass* x, Klass** list) {
1288 for (int i = 0; ; i++) {
1289 Klass* y = list[i];
1290 if (y == NULL) break;
1291 if (y == x) return true;
1292 }
1293 return false; // not in list
1294 }
1295
1296 private:
1297 // the actual search method:
1298 Klass* find_witness_anywhere(Klass* context_type,
1299 bool participants_hide_witnesses,
1300 bool top_level_call = true);
1301 // the spot-checking version:
1302 Klass* find_witness_in(KlassDepChange& changes,
1303 Klass* context_type,
1304 bool participants_hide_witnesses);
1305 public:
1306 Klass* find_witness_subtype(Klass* context_type, KlassDepChange* changes = NULL) {
1307 assert(doing_subtype_search(), "must set up a subtype search");
1308 // When looking for unexpected concrete types,
1309 // do not look beneath expected ones.
1310 const bool participants_hide_witnesses = true;
1311 // CX > CC > C' is OK, even if C' is new.
1312 // CX > { CC, C' } is not OK if C' is new, and C' is the witness.
1313 if (changes != NULL) {
1314 return find_witness_in(*changes, context_type, participants_hide_witnesses);
1315 } else {
1316 return find_witness_anywhere(context_type, participants_hide_witnesses);
1317 }
1318 }
1319 Klass* find_witness_definer(Klass* context_type, KlassDepChange* changes = NULL) {
1320 assert(!doing_subtype_search(), "must set up a method definer search");
1321 // When looking for unexpected concrete methods,
1322 // look beneath expected ones, to see if there are overrides.
1323 const bool participants_hide_witnesses = true;
1324 // CX.m > CC.m > C'.m is not OK, if C'.m is new, and C' is the witness.
1325 if (changes != NULL) {
1326 return find_witness_in(*changes, context_type, !participants_hide_witnesses);
1327 } else {
1328 return find_witness_anywhere(context_type, !participants_hide_witnesses);
1329 }
1330 }
1331 };
1332
1333 #ifndef PRODUCT
1334 static int deps_find_witness_calls = 0;
1335 static int deps_find_witness_steps = 0;
1336 static int deps_find_witness_recursions = 0;
1337 static int deps_find_witness_singles = 0;
1338 static int deps_find_witness_print = 0; // set to -1 to force a final print
1339 static bool count_find_witness_calls() {
1340 if (TraceDependencies || LogCompilation) {
1341 int pcount = deps_find_witness_print + 1;
1342 bool final_stats = (pcount == 0);
1343 bool initial_call = (pcount == 1);
1344 bool occasional_print = ((pcount & ((1<<10) - 1)) == 0);
1345 if (pcount < 0) pcount = 1; // crude overflow protection
1346 deps_find_witness_print = pcount;
1347 if (VerifyDependencies && initial_call) {
1348 tty->print_cr("Warning: TraceDependencies results may be inflated by VerifyDependencies");
1349 }
1350 if (occasional_print || final_stats) {
1351 // Every now and then dump a little info about dependency searching.
1352 if (xtty != NULL) {
1353 ttyLocker ttyl;
1354 xtty->elem("deps_find_witness calls='%d' steps='%d' recursions='%d' singles='%d'",
1355 deps_find_witness_calls,
1356 deps_find_witness_steps,
1357 deps_find_witness_recursions,
1358 deps_find_witness_singles);
1359 }
1360 if (final_stats || (TraceDependencies && WizardMode)) {
1361 ttyLocker ttyl;
1362 tty->print_cr("Dependency check (find_witness) "
1363 "calls=%d, steps=%d (avg=%.1f), recursions=%d, singles=%d",
1364 deps_find_witness_calls,
1365 deps_find_witness_steps,
1366 (double)deps_find_witness_steps / deps_find_witness_calls,
1367 deps_find_witness_recursions,
1368 deps_find_witness_singles);
1369 }
1370 }
1371 return true;
1372 }
1373 return false;
1374 }
1375 #else
1376 #define count_find_witness_calls() (0)
1377 #endif //PRODUCT
1378
1379
1380 Klass* ClassHierarchyWalker::find_witness_in(KlassDepChange& changes,
1381 Klass* context_type,
1382 bool participants_hide_witnesses) {
1383 assert(changes.involves_context(context_type), "irrelevant dependency");
1384 Klass* new_type = changes.new_type();
1385
1386 (void)count_find_witness_calls();
1387 NOT_PRODUCT(deps_find_witness_singles++);
1388
1389 // Current thread must be in VM (not native mode, as in CI):
1390 assert(must_be_in_vm(), "raw oops here");
1391 // Must not move the class hierarchy during this check:
1392 assert_locked_or_safepoint(Compile_lock);
1393
1394 int nof_impls = InstanceKlass::cast(context_type)->nof_implementors();
1395 if (nof_impls > 1) {
1396 // Avoid this case: *I.m > { A.m, C }; B.m > C
1397 // %%% Until this is fixed more systematically, bail out.
1398 // See corresponding comment in find_witness_anywhere.
1399 return context_type;
1400 }
1401
1402 assert(!is_participant(new_type), "only old classes are participants");
1403 if (participants_hide_witnesses) {
1404 // If the new type is a subtype of a participant, we are done.
1405 for (int i = 0; i < num_participants(); i++) {
1406 Klass* part = participant(i);
1407 if (part == NULL) continue;
1408 assert(changes.involves_context(part) == new_type->is_subtype_of(part),
1409 "correct marking of participants, b/c new_type is unique");
1410 if (changes.involves_context(part)) {
1411 // new guy is protected from this check by previous participant
1412 return NULL;
1413 }
1414 }
1415 }
1416
1417 if (is_witness(new_type) &&
1418 !ignore_witness(new_type)) {
1419 return new_type;
1420 }
1421
1422 return NULL;
1423 }
1424
1425
1426 // Walk hierarchy under a context type, looking for unexpected types.
1427 // Do not report participant types, and recursively walk beneath
1428 // them only if participants_hide_witnesses is false.
1429 // If top_level_call is false, skip testing the context type,
1430 // because the caller has already considered it.
1431 Klass* ClassHierarchyWalker::find_witness_anywhere(Klass* context_type,
1432 bool participants_hide_witnesses,
1433 bool top_level_call) {
1434 // Current thread must be in VM (not native mode, as in CI):
1435 assert(must_be_in_vm(), "raw oops here");
1436 // Must not move the class hierarchy during this check:
1437 assert_locked_or_safepoint(Compile_lock);
1438
1439 bool do_counts = count_find_witness_calls();
1440
1441 // Check the root of the sub-hierarchy first.
1442 if (top_level_call) {
1443 if (do_counts) {
1444 NOT_PRODUCT(deps_find_witness_calls++);
1445 NOT_PRODUCT(deps_find_witness_steps++);
1446 }
1447 if (is_participant(context_type)) {
1448 if (participants_hide_witnesses) return NULL;
1449 // else fall through to search loop...
1450 } else if (is_witness(context_type) && !ignore_witness(context_type)) {
1451 // The context is an abstract class or interface, to start with.
1452 return context_type;
1453 }
1454 }
1455
1456 // Now we must check each implementor and each subclass.
1457 // Use a short worklist to avoid blowing the stack.
1458 // Each worklist entry is a *chain* of subklass siblings to process.
1459 const int CHAINMAX = 100; // >= 1 + InstanceKlass::implementors_limit
1460 Klass* chains[CHAINMAX];
1461 int chaini = 0; // index into worklist
1462 Klass* chain; // scratch variable
1463 #define ADD_SUBCLASS_CHAIN(k) { \
1464 assert(chaini < CHAINMAX, "oob"); \
1465 chain = k->subklass(); \
1466 if (chain != NULL) chains[chaini++] = chain; }
1467
1468 // Look for non-abstract subclasses.
1469 // (Note: Interfaces do not have subclasses.)
1470 ADD_SUBCLASS_CHAIN(context_type);
1471
1472 // If it is an interface, search its direct implementors.
1473 // (Their subclasses are additional indirect implementors.
1474 // See InstanceKlass::add_implementor.)
1475 // (Note: nof_implementors is always zero for non-interfaces.)
1476 if (top_level_call) {
1477 int nof_impls = InstanceKlass::cast(context_type)->nof_implementors();
1478 if (nof_impls > 1) {
1479 // Avoid this case: *I.m > { A.m, C }; B.m > C
1480 // Here, I.m has 2 concrete implementations, but m appears unique
1481 // as A.m, because the search misses B.m when checking C.
1482 // The inherited method B.m was getting missed by the walker
1483 // when interface 'I' was the starting point.
1484 // %%% Until this is fixed more systematically, bail out.
1485 // (Old CHA had the same limitation.)
1486 return context_type;
1487 }
1488 if (nof_impls > 0) {
1489 Klass* impl = InstanceKlass::cast(context_type)->implementor();
1490 assert(impl != NULL, "just checking");
1491 // If impl is the same as the context_type, then more than one
1492 // implementor has seen. No exact info in this case.
1493 if (impl == context_type) {
1494 return context_type; // report an inexact witness to this sad affair
1495 }
1496 if (do_counts)
1497 { NOT_PRODUCT(deps_find_witness_steps++); }
1498 if (is_participant(impl)) {
1499 if (!participants_hide_witnesses) {
1500 ADD_SUBCLASS_CHAIN(impl);
1501 }
1502 } else if (is_witness(impl) && !ignore_witness(impl)) {
1503 return impl;
1504 } else {
1505 ADD_SUBCLASS_CHAIN(impl);
1506 }
1507 }
1508 }
1509
1510 // Recursively process each non-trivial sibling chain.
1511 while (chaini > 0) {
1512 Klass* chain = chains[--chaini];
1513 for (Klass* sub = chain; sub != NULL; sub = sub->next_sibling()) {
1514 if (do_counts) { NOT_PRODUCT(deps_find_witness_steps++); }
1515 if (is_participant(sub)) {
1516 if (participants_hide_witnesses) continue;
1517 // else fall through to process this guy's subclasses
1518 } else if (is_witness(sub) && !ignore_witness(sub)) {
1519 return sub;
1520 }
1521 if (chaini < (VerifyDependencies? 2: CHAINMAX)) {
1522 // Fast path. (Partially disabled if VerifyDependencies.)
1523 ADD_SUBCLASS_CHAIN(sub);
1524 } else {
1525 // Worklist overflow. Do a recursive call. Should be rare.
1526 // The recursive call will have its own worklist, of course.
1527 // (Note that sub has already been tested, so that there is
1528 // no need for the recursive call to re-test. That's handy,
1529 // since the recursive call sees sub as the context_type.)
1530 if (do_counts) { NOT_PRODUCT(deps_find_witness_recursions++); }
1531 Klass* witness = find_witness_anywhere(sub,
1532 participants_hide_witnesses,
1533 /*top_level_call=*/ false);
1534 if (witness != NULL) return witness;
1535 }
1536 }
1537 }
1538
1539 // No witness found. The dependency remains unbroken.
1540 return NULL;
1541 #undef ADD_SUBCLASS_CHAIN
1542 }
1543
1544
1545 bool Dependencies::is_concrete_klass(Klass* k) {
1546 if (k->is_abstract()) return false;
1547 // %%% We could treat classes which are concrete but
1548 // have not yet been instantiated as virtually abstract.
1549 // This would require a deoptimization barrier on first instantiation.
1550 //if (k->is_not_instantiated()) return false;
1551 return true;
1552 }
1553
1554 bool Dependencies::is_concrete_method(Method* m, Klass * k) {
1555 // NULL is not a concrete method,
1556 // statics are irrelevant to virtual call sites,
1557 // abstract methods are not concrete,
1558 // overpass (error) methods are not concrete if k is abstract
1559 //
1560 // note "true" is conservative answer --
1561 // overpass clause is false if k == NULL, implies return true if
1562 // answer depends on overpass clause.
1563 return ! ( m == NULL || m -> is_static() || m -> is_abstract() ||
1564 (m->is_overpass() && k != NULL && k -> is_abstract()) );
1565 }
1566
1567
1568 Klass* Dependencies::find_finalizable_subclass(Klass* k) {
1569 if (k->is_interface()) return NULL;
1570 if (k->has_finalizer()) return k;
1571 k = k->subklass();
1572 while (k != NULL) {
1573 Klass* result = find_finalizable_subclass(k);
1574 if (result != NULL) return result;
1575 k = k->next_sibling();
1576 }
1577 return NULL;
1578 }
1579
1580
1581 bool Dependencies::is_concrete_klass(ciInstanceKlass* k) {
1582 if (k->is_abstract()) return false;
1583 // We could also return false if k does not yet appear to be
1584 // instantiated, if the VM version supports this distinction also.
1585 //if (k->is_not_instantiated()) return false;
1586 return true;
1587 }
1588
1589 bool Dependencies::has_finalizable_subclass(ciInstanceKlass* k) {
1590 return k->has_finalizable_subclass();
1591 }
1592
1593
1594 // Any use of the contents (bytecodes) of a method must be
1595 // marked by an "evol_method" dependency, if those contents
1596 // can change. (Note: A method is always dependent on itself.)
1597 Klass* Dependencies::check_evol_method(Method* m) {
1598 assert(must_be_in_vm(), "raw oops here");
1599 // Did somebody do a JVMTI RedefineClasses while our backs were turned?
1600 // Or is there a now a breakpoint?
1601 // (Assumes compiled code cannot handle bkpts; change if UseFastBreakpoints.)
1602 if (m->is_old()
1603 || m->number_of_breakpoints() > 0) {
1604 return m->method_holder();
1605 } else {
1606 return NULL;
1607 }
1608 }
1609
1610 // This is a strong assertion: It is that the given type
1611 // has no subtypes whatever. It is most useful for
1612 // optimizing checks on reflected types or on array types.
1613 // (Checks on types which are derived from real instances
1614 // can be optimized more strongly than this, because we
1615 // know that the checked type comes from a concrete type,
1616 // and therefore we can disregard abstract types.)
1617 Klass* Dependencies::check_leaf_type(Klass* ctxk) {
1618 assert(must_be_in_vm(), "raw oops here");
1619 assert_locked_or_safepoint(Compile_lock);
1620 InstanceKlass* ctx = InstanceKlass::cast(ctxk);
1621 Klass* sub = ctx->subklass();
1622 if (sub != NULL) {
1623 return sub;
1624 } else if (ctx->nof_implementors() != 0) {
1625 // if it is an interface, it must be unimplemented
1626 // (if it is not an interface, nof_implementors is always zero)
1627 Klass* impl = ctx->implementor();
1628 assert(impl != NULL, "must be set");
1629 return impl;
1630 } else {
1631 return NULL;
1632 }
1633 }
1634
1635 // Test the assertion that conck is the only concrete subtype* of ctxk.
1636 // The type conck itself is allowed to have have further concrete subtypes.
1637 // This allows the compiler to narrow occurrences of ctxk by conck,
1638 // when dealing with the types of actual instances.
1639 Klass* Dependencies::check_abstract_with_unique_concrete_subtype(Klass* ctxk,
1640 Klass* conck,
1641 KlassDepChange* changes) {
1642 ClassHierarchyWalker wf(conck);
1643 return wf.find_witness_subtype(ctxk, changes);
1644 }
1645
1646 // If a non-concrete class has no concrete subtypes, it is not (yet)
1647 // instantiatable. This can allow the compiler to make some paths go
1648 // dead, if they are gated by a test of the type.
1649 Klass* Dependencies::check_abstract_with_no_concrete_subtype(Klass* ctxk,
1650 KlassDepChange* changes) {
1651 // Find any concrete subtype, with no participants:
1652 ClassHierarchyWalker wf;
1653 return wf.find_witness_subtype(ctxk, changes);
1654 }
1655
1656
1657 // If a concrete class has no concrete subtypes, it can always be
1658 // exactly typed. This allows the use of a cheaper type test.
1659 Klass* Dependencies::check_concrete_with_no_concrete_subtype(Klass* ctxk,
1660 KlassDepChange* changes) {
1661 // Find any concrete subtype, with only the ctxk as participant:
1662 ClassHierarchyWalker wf(ctxk);
1663 return wf.find_witness_subtype(ctxk, changes);
1664 }
1665
1666
1667 // Find the unique concrete proper subtype of ctxk, or NULL if there
1668 // is more than one concrete proper subtype. If there are no concrete
1669 // proper subtypes, return ctxk itself, whether it is concrete or not.
1670 // The returned subtype is allowed to have have further concrete subtypes.
1671 // That is, return CC1 for CX > CC1 > CC2, but NULL for CX > { CC1, CC2 }.
1672 Klass* Dependencies::find_unique_concrete_subtype(Klass* ctxk) {
1673 ClassHierarchyWalker wf(ctxk); // Ignore ctxk when walking.
1674 wf.record_witnesses(1); // Record one other witness when walking.
1675 Klass* wit = wf.find_witness_subtype(ctxk);
1676 if (wit != NULL) return NULL; // Too many witnesses.
1677 Klass* conck = wf.participant(0);
1678 if (conck == NULL) {
1679 #ifndef PRODUCT
1680 // Make sure the dependency mechanism will pass this discovery:
1681 if (VerifyDependencies) {
1682 // Turn off dependency tracing while actually testing deps.
1683 FlagSetting fs(TraceDependencies, false);
1684 if (!Dependencies::is_concrete_klass(ctxk)) {
1685 guarantee(NULL ==
1686 (void *)check_abstract_with_no_concrete_subtype(ctxk),
1687 "verify dep.");
1688 } else {
1689 guarantee(NULL ==
1690 (void *)check_concrete_with_no_concrete_subtype(ctxk),
1691 "verify dep.");
1692 }
1693 }
1694 #endif //PRODUCT
1695 return ctxk; // Return ctxk as a flag for "no subtypes".
1696 } else {
1697 #ifndef PRODUCT
1698 // Make sure the dependency mechanism will pass this discovery:
1699 if (VerifyDependencies) {
1700 // Turn off dependency tracing while actually testing deps.
1701 FlagSetting fs(TraceDependencies, false);
1702 if (!Dependencies::is_concrete_klass(ctxk)) {
1703 guarantee(NULL == (void *)
1704 check_abstract_with_unique_concrete_subtype(ctxk, conck),
1705 "verify dep.");
1706 }
1707 }
1708 #endif //PRODUCT
1709 return conck;
1710 }
1711 }
1712
1713 // Test the assertion that the k[12] are the only concrete subtypes of ctxk,
1714 // except possibly for further subtypes of k[12] themselves.
1715 // The context type must be abstract. The types k1 and k2 are themselves
1716 // allowed to have further concrete subtypes.
1717 Klass* Dependencies::check_abstract_with_exclusive_concrete_subtypes(
1718 Klass* ctxk,
1719 Klass* k1,
1720 Klass* k2,
1721 KlassDepChange* changes) {
1722 ClassHierarchyWalker wf;
1723 wf.add_participant(k1);
1724 wf.add_participant(k2);
1725 return wf.find_witness_subtype(ctxk, changes);
1726 }
1727
1728 // Search ctxk for concrete implementations. If there are klen or fewer,
1729 // pack them into the given array and return the number.
1730 // Otherwise, return -1, meaning the given array would overflow.
1731 // (Note that a return of 0 means there are exactly no concrete subtypes.)
1732 // In this search, if ctxk is concrete, it will be reported alone.
1733 // For any type CC reported, no proper subtypes of CC will be reported.
1734 int Dependencies::find_exclusive_concrete_subtypes(Klass* ctxk,
1735 int klen,
1736 Klass* karray[]) {
1737 ClassHierarchyWalker wf;
1738 wf.record_witnesses(klen);
1739 Klass* wit = wf.find_witness_subtype(ctxk);
1740 if (wit != NULL) return -1; // Too many witnesses.
1741 int num = wf.num_participants();
1742 assert(num <= klen, "oob");
1743 // Pack the result array with the good news.
1744 for (int i = 0; i < num; i++)
1745 karray[i] = wf.participant(i);
1746 #ifndef PRODUCT
1747 // Make sure the dependency mechanism will pass this discovery:
1748 if (VerifyDependencies) {
1749 // Turn off dependency tracing while actually testing deps.
1750 FlagSetting fs(TraceDependencies, false);
1751 switch (Dependencies::is_concrete_klass(ctxk)? -1: num) {
1752 case -1: // ctxk was itself concrete
1753 guarantee(num == 1 && karray[0] == ctxk, "verify dep.");
1754 break;
1755 case 0:
1756 guarantee(NULL == (void *)check_abstract_with_no_concrete_subtype(ctxk),
1757 "verify dep.");
1758 break;
1759 case 1:
1760 guarantee(NULL == (void *)
1761 check_abstract_with_unique_concrete_subtype(ctxk, karray[0]),
1762 "verify dep.");
1763 break;
1764 case 2:
1765 guarantee(NULL == (void *)
1766 check_abstract_with_exclusive_concrete_subtypes(ctxk,
1767 karray[0],
1768 karray[1]),
1769 "verify dep.");
1770 break;
1771 default:
1772 ShouldNotReachHere(); // klen > 2 yet supported
1773 }
1774 }
1775 #endif //PRODUCT
1776 return num;
1777 }
1778
1779 // If a class (or interface) has a unique concrete method uniqm, return NULL.
1780 // Otherwise, return a class that contains an interfering method.
1781 Klass* Dependencies::check_unique_concrete_method(Klass* ctxk, Method* uniqm,
1782 KlassDepChange* changes) {
1783 // Here is a missing optimization: If uniqm->is_final(),
1784 // we don't really need to search beneath it for overrides.
1785 // This is probably not important, since we don't use dependencies
1786 // to track final methods. (They can't be "definalized".)
1787 ClassHierarchyWalker wf(uniqm->method_holder(), uniqm);
1788 return wf.find_witness_definer(ctxk, changes);
1789 }
1790
1791 // Find the set of all non-abstract methods under ctxk that match m.
1792 // (The method m must be defined or inherited in ctxk.)
1793 // Include m itself in the set, unless it is abstract.
1794 // If this set has exactly one element, return that element.
1795 Method* Dependencies::find_unique_concrete_method(Klass* ctxk, Method* m) {
1796 // Return NULL if m is marked old; must have been a redefined method.
1797 if (m->is_old()) {
1798 return NULL;
1799 }
1800 ClassHierarchyWalker wf(m);
1801 assert(wf.check_method_context(ctxk, m), "proper context");
1802 wf.record_witnesses(1);
1803 Klass* wit = wf.find_witness_definer(ctxk);
1804 if (wit != NULL) return NULL; // Too many witnesses.
1805 Method* fm = wf.found_method(0); // Will be NULL if num_parts == 0.
1806 if (Dependencies::is_concrete_method(m, ctxk)) {
1807 if (fm == NULL) {
1808 // It turns out that m was always the only implementation.
1809 fm = m;
1810 } else if (fm != m) {
1811 // Two conflicting implementations after all.
1812 // (This can happen if m is inherited into ctxk and fm overrides it.)
1813 return NULL;
1814 }
1815 }
1816 #ifndef PRODUCT
1817 // Make sure the dependency mechanism will pass this discovery:
1818 if (VerifyDependencies && fm != NULL) {
1819 guarantee(NULL == (void *)check_unique_concrete_method(ctxk, fm),
1820 "verify dep.");
1821 }
1822 #endif //PRODUCT
1823 return fm;
1824 }
1825
1826 Klass* Dependencies::check_exclusive_concrete_methods(Klass* ctxk,
1827 Method* m1,
1828 Method* m2,
1829 KlassDepChange* changes) {
1830 ClassHierarchyWalker wf(m1);
1831 wf.add_participant(m1->method_holder());
1832 wf.add_participant(m2->method_holder());
1833 return wf.find_witness_definer(ctxk, changes);
1834 }
1835
1836 Klass* Dependencies::check_has_no_finalizable_subclasses(Klass* ctxk, KlassDepChange* changes) {
1837 Klass* search_at = ctxk;
1838 if (changes != NULL)
1839 search_at = changes->new_type(); // just look at the new bit
1840 return find_finalizable_subclass(search_at);
1841 }
1842
1843 Klass* Dependencies::check_call_site_target_value(oop call_site, oop method_handle, CallSiteDepChange* changes) {
1844 assert(call_site != NULL, "sanity");
1845 assert(method_handle != NULL, "sanity");
1846 assert(call_site->is_a(SystemDictionary::CallSite_klass()), "sanity");
1847
1848 if (changes == NULL) {
1849 // Validate all CallSites
1850 if (!oopDesc::equals(java_lang_invoke_CallSite::target(call_site), method_handle))
1851 return call_site->klass(); // assertion failed
1852 } else {
1853 // Validate the given CallSite
1854 if (oopDesc::equals(call_site, changes->call_site()) && !oopDesc::equals(java_lang_invoke_CallSite::target(call_site), changes->method_handle())) {
1855 assert(!oopDesc::equals(method_handle, changes->method_handle()), "must be");
1856 return call_site->klass(); // assertion failed
1857 }
1858 }
1859 return NULL; // assertion still valid
1860 }
1861
1862 void Dependencies::DepStream::trace_and_log_witness(Klass* witness) {
1863 if (witness != NULL) {
1864 if (TraceDependencies) {
1865 print_dependency(witness, /*verbose=*/ true);
1866 }
1867 // The following is a no-op unless logging is enabled:
1868 log_dependency(witness);
1869 }
1870 }
1871
1872
1873 Klass* Dependencies::DepStream::check_klass_dependency(KlassDepChange* changes) {
1874 assert_locked_or_safepoint(Compile_lock);
1875 Dependencies::check_valid_dependency_type(type());
1876
1877 Klass* witness = NULL;
1878 switch (type()) {
1879 case evol_method:
1880 witness = check_evol_method(method_argument(0));
1881 break;
1882 case leaf_type:
1883 witness = check_leaf_type(context_type());
1884 break;
1885 case abstract_with_unique_concrete_subtype:
1886 witness = check_abstract_with_unique_concrete_subtype(context_type(), type_argument(1), changes);
1887 break;
1888 case abstract_with_no_concrete_subtype:
1889 witness = check_abstract_with_no_concrete_subtype(context_type(), changes);
1890 break;
1891 case concrete_with_no_concrete_subtype:
1892 witness = check_concrete_with_no_concrete_subtype(context_type(), changes);
1893 break;
1894 case unique_concrete_method:
1895 witness = check_unique_concrete_method(context_type(), method_argument(1), changes);
1896 break;
1897 case abstract_with_exclusive_concrete_subtypes_2:
1898 witness = check_abstract_with_exclusive_concrete_subtypes(context_type(), type_argument(1), type_argument(2), changes);
1899 break;
1900 case exclusive_concrete_methods_2:
1901 witness = check_exclusive_concrete_methods(context_type(), method_argument(1), method_argument(2), changes);
1902 break;
1903 case no_finalizable_subclasses:
1904 witness = check_has_no_finalizable_subclasses(context_type(), changes);
1905 break;
1906 default:
1907 witness = NULL;
1908 break;
1909 }
1910 trace_and_log_witness(witness);
1911 return witness;
1912 }
1913
1914
1915 Klass* Dependencies::DepStream::check_call_site_dependency(CallSiteDepChange* changes) {
1916 assert_locked_or_safepoint(Compile_lock);
1917 Dependencies::check_valid_dependency_type(type());
1918
1919 Klass* witness = NULL;
1920 switch (type()) {
1921 case call_site_target_value:
1922 witness = check_call_site_target_value(argument_oop(0), argument_oop(1), changes);
1923 break;
1924 default:
1925 witness = NULL;
1926 break;
1927 }
1928 trace_and_log_witness(witness);
1929 return witness;
1930 }
1931
1932
1933 Klass* Dependencies::DepStream::spot_check_dependency_at(DepChange& changes) {
1934 // Handle klass dependency
1935 if (changes.is_klass_change() && changes.as_klass_change()->involves_context(context_type()))
1936 return check_klass_dependency(changes.as_klass_change());
1937
1938 // Handle CallSite dependency
1939 if (changes.is_call_site_change())
1940 return check_call_site_dependency(changes.as_call_site_change());
1941
1942 // irrelevant dependency; skip it
1943 return NULL;
1944 }
1945
1946
1947 void DepChange::print() {
1948 int nsup = 0, nint = 0;
1949 for (ContextStream str(*this); str.next(); ) {
1950 Klass* k = str.klass();
1951 switch (str.change_type()) {
1952 case Change_new_type:
1953 tty->print_cr(" dependee = %s", k->external_name());
1954 break;
1955 case Change_new_sub:
1956 if (!WizardMode) {
1957 ++nsup;
1958 } else {
1959 tty->print_cr(" context super = %s", k->external_name());
1960 }
1961 break;
1962 case Change_new_impl:
1963 if (!WizardMode) {
1964 ++nint;
1965 } else {
1966 tty->print_cr(" context interface = %s", k->external_name());
1967 }
1968 break;
1969 default:
1970 break;
1971 }
1972 }
1973 if (nsup + nint != 0) {
1974 tty->print_cr(" context supers = %d, interfaces = %d", nsup, nint);
1975 }
1976 }
1977
1978 void DepChange::ContextStream::start() {
1979 Klass* new_type = _changes.is_klass_change() ? _changes.as_klass_change()->new_type() : (Klass*) NULL;
1980 _change_type = (new_type == NULL ? NO_CHANGE : Start_Klass);
1981 _klass = new_type;
1982 _ti_base = NULL;
1983 _ti_index = 0;
1984 _ti_limit = 0;
1985 }
1986
1987 bool DepChange::ContextStream::next() {
1988 switch (_change_type) {
1989 case Start_Klass: // initial state; _klass is the new type
1990 _ti_base = InstanceKlass::cast(_klass)->transitive_interfaces();
1991 _ti_index = 0;
1992 _change_type = Change_new_type;
1993 return true;
1994 case Change_new_type:
1995 // fall through:
1996 _change_type = Change_new_sub;
1997 case Change_new_sub:
1998 // 6598190: brackets workaround Sun Studio C++ compiler bug 6629277
1999 {
2000 _klass = _klass->super();
2001 if (_klass != NULL) {
2002 return true;
2003 }
2004 }
2005 // else set up _ti_limit and fall through:
2006 _ti_limit = (_ti_base == NULL) ? 0 : _ti_base->length();
2007 _change_type = Change_new_impl;
2008 case Change_new_impl:
2009 if (_ti_index < _ti_limit) {
2010 _klass = _ti_base->at(_ti_index++);
2011 return true;
2012 }
2013 // fall through:
2014 _change_type = NO_CHANGE; // iterator is exhausted
2015 case NO_CHANGE:
2016 break;
2017 default:
2018 ShouldNotReachHere();
2019 }
2020 return false;
2021 }
2022
2023 void KlassDepChange::initialize() {
2024 // entire transaction must be under this lock:
2025 assert_lock_strong(Compile_lock);
2026
2027 // Mark all dependee and all its superclasses
2028 // Mark transitive interfaces
2029 for (ContextStream str(*this); str.next(); ) {
2030 Klass* d = str.klass();
2031 assert(!InstanceKlass::cast(d)->is_marked_dependent(), "checking");
2032 InstanceKlass::cast(d)->set_is_marked_dependent(true);
2033 }
2034 }
2035
2036 KlassDepChange::~KlassDepChange() {
2037 // Unmark all dependee and all its superclasses
2038 // Unmark transitive interfaces
2039 for (ContextStream str(*this); str.next(); ) {
2040 Klass* d = str.klass();
2041 InstanceKlass::cast(d)->set_is_marked_dependent(false);
2042 }
2043 }
2044
2045 bool KlassDepChange::involves_context(Klass* k) {
2046 if (k == NULL || !k->is_instance_klass()) {
2047 return false;
2048 }
2049 InstanceKlass* ik = InstanceKlass::cast(k);
2050 bool is_contained = ik->is_marked_dependent();
2051 assert(is_contained == new_type()->is_subtype_of(k),
2052 "correct marking of potential context types");
2053 return is_contained;
2054 }
2055
2056 #ifndef PRODUCT
2057 void Dependencies::print_statistics() {
2058 if (deps_find_witness_print != 0) {
2059 // Call one final time, to flush out the data.
2060 deps_find_witness_print = -1;
2061 count_find_witness_calls();
2062 }
2063 }
2064 #endif
2065
2066 CallSiteDepChange::CallSiteDepChange(Handle call_site, Handle method_handle) :
2067 _call_site(call_site),
2068 _method_handle(method_handle) {
2069 assert(_call_site()->is_a(SystemDictionary::CallSite_klass()), "must be");
2070 assert(_method_handle.is_null() || _method_handle()->is_a(SystemDictionary::MethodHandle_klass()), "must be");
2071 }