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