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