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