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