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 }
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 Thread* thread = Thread::current();
718 HandleMark rm(thread);
719 ttyLocker ttyl;
720 int ctxkj = dep_context_arg(dept); // -1 if no context arg
721 if (witness != NULL) {
722 xtty->begin_elem("dependency_failed");
723 } else {
724 xtty->begin_elem("dependency");
725 }
726 xtty->print(" type='%s'", dep_name(dept));
727 if (ctxkj >= 0) {
728 xtty->object("ctxk", args->at(ctxkj).metadata_value());
729 }
730 // write remaining arguments, if any.
731 for (int j = 0; j < args->length(); j++) {
732 if (j == ctxkj) continue; // already logged
733 DepArgument arg = args->at(j);
734 if (j == 1) {
735 if (arg.is_oop()) {
736 xtty->object("x", Handle(thread, arg.oop_value()));
737 } else {
738 xtty->object("x", arg.metadata_value());
739 }
740 } else {
741 char xn[10]; sprintf(xn, "x%d", j);
742 if (arg.is_oop()) {
743 xtty->object(xn, Handle(thread, arg.oop_value()));
744 } else {
745 xtty->object(xn, arg.metadata_value());
746 }
747 }
748 }
749 if (witness != NULL) {
750 xtty->object("witness", witness);
751 xtty->stamp();
752 }
753 xtty->end_elem();
754 }
755
756 void Dependencies::print_dependency(DepType dept, GrowableArray<DepArgument>* args,
757 Klass* witness, outputStream* st) {
758 ResourceMark rm;
759 ttyLocker ttyl; // keep the following output all in one block
760 st->print_cr("%s of type %s",
761 (witness == NULL)? "Dependency": "Failed dependency",
762 dep_name(dept));
763 // print arguments
764 int ctxkj = dep_context_arg(dept); // -1 if no context arg
765 for (int j = 0; j < args->length(); j++) {
766 DepArgument arg = args->at(j);
767 bool put_star = false;
768 if (arg.is_null()) continue;
769 const char* what;
770 if (j == ctxkj) {
771 assert(arg.is_metadata(), "must be");
772 what = "context";
773 put_star = !Dependencies::is_concrete_klass((Klass*)arg.metadata_value());
774 } else if (arg.is_method()) {
775 what = "method ";
776 put_star = !Dependencies::is_concrete_method((Method*)arg.metadata_value(), NULL);
777 } else if (arg.is_klass()) {
778 what = "class ";
779 } else {
780 what = "object ";
781 }
782 st->print(" %s = %s", what, (put_star? "*": ""));
783 if (arg.is_klass()) {
784 st->print("%s", ((Klass*)arg.metadata_value())->external_name());
785 } else if (arg.is_method()) {
786 ((Method*)arg.metadata_value())->print_value_on(st);
787 } else if (arg.is_oop()) {
788 arg.oop_value()->print_value_on(st);
789 } else {
790 ShouldNotReachHere(); // Provide impl for this type.
791 }
792
793 st->cr();
794 }
795 if (witness != NULL) {
796 bool put_star = !Dependencies::is_concrete_klass(witness);
797 st->print_cr(" witness = %s%s",
798 (put_star? "*": ""),
799 witness->external_name());
800 }
801 }
802
803 void Dependencies::DepStream::log_dependency(Klass* witness) {
804 if (_deps == NULL && xtty == NULL) return; // fast cutout for runtime
805 ResourceMark rm;
806 const int nargs = argument_count();
807 GrowableArray<DepArgument>* args = new GrowableArray<DepArgument>(nargs);
808 for (int j = 0; j < nargs; j++) {
809 if (is_oop_argument(j)) {
810 args->push(argument_oop(j));
811 } else {
812 args->push(argument(j));
813 }
814 }
815 int argslen = args->length();
816 if (_deps != NULL && _deps->log() != NULL) {
817 if (ciEnv::current() != NULL) {
818 Dependencies::write_dependency_to(_deps->log(), type(), args, witness);
819 } else {
820 // Treat the CompileLog as an xmlstream instead
821 Dependencies::write_dependency_to((xmlStream*)_deps->log(), type(), args, witness);
822 }
823 } else {
824 Dependencies::write_dependency_to(xtty, type(), args, witness);
825 }
826 guarantee(argslen == args->length(), "args array cannot grow inside nested ResoureMark scope");
827 }
828
829 void Dependencies::DepStream::print_dependency(Klass* witness, bool verbose, outputStream* st) {
830 ResourceMark rm;
831 int nargs = argument_count();
832 GrowableArray<DepArgument>* args = new GrowableArray<DepArgument>(nargs);
833 for (int j = 0; j < nargs; j++) {
834 if (is_oop_argument(j)) {
835 args->push(argument_oop(j));
836 } else {
837 args->push(argument(j));
838 }
839 }
840 int argslen = args->length();
841 Dependencies::print_dependency(type(), args, witness, st);
842 if (verbose) {
843 if (_code != NULL) {
844 st->print(" code: ");
845 _code->print_value_on(st);
846 st->cr();
847 }
848 }
849 guarantee(argslen == args->length(), "args array cannot grow inside nested ResoureMark scope");
850 }
851
852
853 /// Dependency stream support (decodes dependencies from an nmethod):
854
855 #ifdef ASSERT
856 void Dependencies::DepStream::initial_asserts(size_t byte_limit) {
857 assert(must_be_in_vm(), "raw oops here");
858 _byte_limit = byte_limit;
859 _type = (DepType)(end_marker-1); // defeat "already at end" assert
860 assert((_code!=NULL) + (_deps!=NULL) == 1, "one or t'other");
861 }
862 #endif //ASSERT
863
864 bool Dependencies::DepStream::next() {
865 assert(_type != end_marker, "already at end");
866 if (_bytes.position() == 0 && _code != NULL
867 && _code->dependencies_size() == 0) {
868 // Method has no dependencies at all.
869 return false;
870 }
871 int code_byte = (_bytes.read_byte() & 0xFF);
872 if (code_byte == end_marker) {
873 DEBUG_ONLY(_type = end_marker);
874 return false;
875 } else {
876 int ctxk_bit = (code_byte & Dependencies::default_context_type_bit);
877 code_byte -= ctxk_bit;
878 DepType dept = (DepType)code_byte;
879 _type = dept;
880 Dependencies::check_valid_dependency_type(dept);
881 int stride = _dep_args[dept];
882 assert(stride == dep_args(dept), "sanity");
883 int skipj = -1;
884 if (ctxk_bit != 0) {
885 skipj = 0; // currently the only context argument is at zero
886 assert(skipj == dep_context_arg(dept), "zero arg always ctxk");
887 }
888 for (int j = 0; j < stride; j++) {
889 _xi[j] = (j == skipj)? 0: _bytes.read_int();
890 }
891 DEBUG_ONLY(_xi[stride] = -1); // help detect overruns
892 return true;
893 }
894 }
895
896 inline Metadata* Dependencies::DepStream::recorded_metadata_at(int i) {
897 Metadata* o = NULL;
898 if (_code != NULL) {
899 o = _code->metadata_at(i);
900 } else {
901 o = _deps->oop_recorder()->metadata_at(i);
902 }
903 return o;
904 }
905
906 inline oop Dependencies::DepStream::recorded_oop_at(int i) {
907 return (_code != NULL)
908 ? _code->oop_at(i)
909 : JNIHandles::resolve(_deps->oop_recorder()->oop_at(i));
910 }
911
912 Metadata* Dependencies::DepStream::argument(int i) {
913 Metadata* result = recorded_metadata_at(argument_index(i));
914
915 if (result == NULL) { // Explicit context argument can be compressed
916 int ctxkj = dep_context_arg(type()); // -1 if no explicit context arg
917 if (ctxkj >= 0 && i == ctxkj && ctxkj+1 < argument_count()) {
918 result = ctxk_encoded_as_null(type(), argument(ctxkj+1));
919 }
920 }
921
922 assert(result == NULL || result->is_klass() || result->is_method(), "must be");
923 return result;
924 }
925
926 /**
927 * Returns a unique identifier for each dependency argument.
928 */
929 uintptr_t Dependencies::DepStream::get_identifier(int i) {
930 if (is_oop_argument(i)) {
931 return (uintptr_t)(oopDesc*)argument_oop(i);
932 } else {
933 return (uintptr_t)argument(i);
934 }
935 }
936
937 oop Dependencies::DepStream::argument_oop(int i) {
938 oop result = recorded_oop_at(argument_index(i));
939 assert(result == NULL || result->is_oop(), "must be");
940 return result;
941 }
942
943 Klass* Dependencies::DepStream::context_type() {
944 assert(must_be_in_vm(), "raw oops here");
945
946 // Most dependencies have an explicit context type argument.
947 {
948 int ctxkj = dep_context_arg(type()); // -1 if no explicit context arg
949 if (ctxkj >= 0) {
950 Metadata* k = argument(ctxkj);
951 assert(k != NULL && k->is_klass(), "type check");
952 return (Klass*)k;
953 }
954 }
955
956 // Some dependencies are using the klass of the first object
957 // argument as implicit context type.
958 {
959 int ctxkj = dep_implicit_context_arg(type());
960 if (ctxkj >= 0) {
961 Klass* k = argument_oop(ctxkj)->klass();
962 assert(k != NULL && k->is_klass(), "type check");
963 return (Klass*) k;
964 }
965 }
966
967 // And some dependencies don't have a context type at all,
968 // e.g. evol_method.
969 return NULL;
970 }
971
972 // ----------------- DependencySignature --------------------------------------
973 bool DependencySignature::equals(DependencySignature const& s1, DependencySignature const& s2) {
974 if ((s1.type() != s2.type()) || (s1.args_count() != s2.args_count())) {
975 return false;
976 }
977
978 for (int i = 0; i < s1.args_count(); i++) {
979 if (s1.arg(i) != s2.arg(i)) {
980 return false;
981 }
982 }
983 return true;
984 }
985
986 /// Checking dependencies:
987
988 // This hierarchy walker inspects subtypes of a given type,
989 // trying to find a "bad" class which breaks a dependency.
990 // Such a class is called a "witness" to the broken dependency.
991 // While searching around, we ignore "participants", which
992 // are already known to the dependency.
993 class ClassHierarchyWalker {
994 public:
995 enum { PARTICIPANT_LIMIT = 3 };
996
997 private:
998 // optional method descriptor to check for:
999 Symbol* _name;
1000 Symbol* _signature;
1001
1002 // special classes which are not allowed to be witnesses:
1003 Klass* _participants[PARTICIPANT_LIMIT+1];
1004 int _num_participants;
1005
1006 // cache of method lookups
1007 Method* _found_methods[PARTICIPANT_LIMIT+1];
1008
1009 // if non-zero, tells how many witnesses to convert to participants
1010 int _record_witnesses;
1011
1012 void initialize(Klass* participant) {
1013 _record_witnesses = 0;
1014 _participants[0] = participant;
1015 _found_methods[0] = NULL;
1016 _num_participants = 0;
1017 if (participant != NULL) {
1018 // Terminating NULL.
1019 _participants[1] = NULL;
1020 _found_methods[1] = NULL;
1021 _num_participants = 1;
1022 }
1023 }
1024
1025 void initialize_from_method(Method* m) {
1026 assert(m != NULL && m->is_method(), "sanity");
1027 _name = m->name();
1028 _signature = m->signature();
1029 }
1030
1031 public:
1032 // The walker is initialized to recognize certain methods and/or types
1033 // as friendly participants.
1034 ClassHierarchyWalker(Klass* participant, Method* m) {
1035 initialize_from_method(m);
1036 initialize(participant);
1037 }
1038 ClassHierarchyWalker(Method* m) {
1039 initialize_from_method(m);
1040 initialize(NULL);
1041 }
1042 ClassHierarchyWalker(Klass* participant = NULL) {
1043 _name = NULL;
1044 _signature = NULL;
1045 initialize(participant);
1046 }
1047
1048 // This is common code for two searches: One for concrete subtypes,
1049 // the other for concrete method implementations and overrides.
1050 bool doing_subtype_search() {
1051 return _name == NULL;
1052 }
1053
1054 int num_participants() { return _num_participants; }
1055 Klass* participant(int n) {
1056 assert((uint)n <= (uint)_num_participants, "oob");
1057 return _participants[n];
1058 }
1059
1060 // Note: If n==num_participants, returns NULL.
1061 Method* found_method(int n) {
1062 assert((uint)n <= (uint)_num_participants, "oob");
1063 Method* fm = _found_methods[n];
1064 assert(n == _num_participants || fm != NULL, "proper usage");
1065 if (fm != NULL && fm->method_holder() != _participants[n]) {
1066 // Default methods from interfaces can be added to classes. In
1067 // that case the holder of the method is not the class but the
1068 // interface where it's defined.
1069 assert(fm->is_default_method(), "sanity");
1070 return NULL;
1071 }
1072 return fm;
1073 }
1074
1075 #ifdef ASSERT
1076 // Assert that m is inherited into ctxk, without intervening overrides.
1077 // (May return true even if this is not true, in corner cases where we punt.)
1078 bool check_method_context(Klass* ctxk, Method* m) {
1079 if (m->method_holder() == ctxk)
1080 return true; // Quick win.
1081 if (m->is_private())
1082 return false; // Quick lose. Should not happen.
1083 if (!(m->is_public() || m->is_protected()))
1084 // The override story is complex when packages get involved.
1085 return true; // Must punt the assertion to true.
1086 Method* lm = ctxk->lookup_method(m->name(), m->signature());
1087 if (lm == NULL && ctxk->is_instance_klass()) {
1088 // It might be an interface method
1089 lm = InstanceKlass::cast(ctxk)->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, ctxk) &&
1105 !Dependencies::is_concrete_method(m, ctxk)) {
1106 // They are both non-concrete
1107 if (lm->method_holder()->is_subtype_of(m->method_holder())) {
1108 // Method m is overridden by lm, but both are non-concrete.
1109 return true;
1110 }
1111 if (lm->method_holder()->is_interface() && m->method_holder()->is_interface() &&
1112 ctxk->is_subtype_of(m->method_holder()) && ctxk->is_subtype_of(lm->method_holder())) {
1113 // Interface method defined in multiple super interfaces
1114 return true;
1115 }
1116 }
1117 }
1118 ResourceMark rm;
1119 tty->print_cr("Dependency method not found in the associated context:");
1120 tty->print_cr(" context = %s", ctxk->external_name());
1121 tty->print( " method = "); m->print_short_name(tty); tty->cr();
1122 if (lm != NULL) {
1123 tty->print( " found = "); lm->print_short_name(tty); tty->cr();
1124 }
1125 return false;
1126 }
1127 #endif
1128
1129 void add_participant(Klass* participant) {
1130 assert(_num_participants + _record_witnesses < PARTICIPANT_LIMIT, "oob");
1131 int np = _num_participants++;
1132 _participants[np] = participant;
1133 _participants[np+1] = NULL;
1134 _found_methods[np+1] = NULL;
1135 }
1136
1137 void record_witnesses(int add) {
1138 if (add > PARTICIPANT_LIMIT) add = PARTICIPANT_LIMIT;
1139 assert(_num_participants + add < PARTICIPANT_LIMIT, "oob");
1140 _record_witnesses = add;
1141 }
1142
1143 bool is_witness(Klass* k) {
1144 if (doing_subtype_search()) {
1145 return Dependencies::is_concrete_klass(k);
1146 } else if (!k->is_instance_klass()) {
1147 return false; // no methods to find in an array type
1148 } else {
1149 // Search class hierarchy first.
1150 Method* m = InstanceKlass::cast(k)->find_instance_method(_name, _signature);
1151 if (!Dependencies::is_concrete_method(m, k)) {
1152 // Check interface defaults also, if any exist.
1153 Array<Method*>* default_methods = InstanceKlass::cast(k)->default_methods();
1154 if (default_methods == NULL)
1155 return false;
1156 m = InstanceKlass::cast(k)->find_method(default_methods, _name, _signature);
1157 if (!Dependencies::is_concrete_method(m, NULL))
1158 return false;
1159 }
1160 _found_methods[_num_participants] = m;
1161 // Note: If add_participant(k) is called,
1162 // the method m will already be memoized for it.
1163 return true;
1164 }
1165 }
1166
1167 bool is_participant(Klass* k) {
1168 if (k == _participants[0]) {
1169 return true;
1170 } else if (_num_participants <= 1) {
1171 return false;
1172 } else {
1173 return in_list(k, &_participants[1]);
1174 }
1175 }
1176 bool ignore_witness(Klass* witness) {
1177 if (_record_witnesses == 0) {
1178 return false;
1179 } else {
1180 --_record_witnesses;
1181 add_participant(witness);
1182 return true;
1183 }
1184 }
1185 static bool in_list(Klass* x, Klass** list) {
1186 for (int i = 0; ; i++) {
1187 Klass* y = list[i];
1188 if (y == NULL) break;
1189 if (y == x) return true;
1190 }
1191 return false; // not in list
1192 }
1193
1194 private:
1195 // the actual search method:
1196 Klass* find_witness_anywhere(Klass* context_type,
1197 bool participants_hide_witnesses,
1198 bool top_level_call = true);
1199 // the spot-checking version:
1200 Klass* find_witness_in(KlassDepChange& changes,
1201 Klass* context_type,
1202 bool participants_hide_witnesses);
1203 public:
1204 Klass* find_witness_subtype(Klass* context_type, KlassDepChange* changes = NULL) {
1205 assert(doing_subtype_search(), "must set up a subtype search");
1206 // When looking for unexpected concrete types,
1207 // do not look beneath expected ones.
1208 const bool participants_hide_witnesses = true;
1209 // CX > CC > C' is OK, even if C' is new.
1210 // CX > { CC, C' } is not OK if C' is new, and C' is the witness.
1211 if (changes != NULL) {
1212 return find_witness_in(*changes, context_type, participants_hide_witnesses);
1213 } else {
1214 return find_witness_anywhere(context_type, participants_hide_witnesses);
1215 }
1216 }
1217 Klass* find_witness_definer(Klass* context_type, KlassDepChange* changes = NULL) {
1218 assert(!doing_subtype_search(), "must set up a method definer search");
1219 // When looking for unexpected concrete methods,
1220 // look beneath expected ones, to see if there are overrides.
1221 const bool participants_hide_witnesses = true;
1222 // CX.m > CC.m > C'.m is not OK, if C'.m is new, and C' is the witness.
1223 if (changes != NULL) {
1224 return find_witness_in(*changes, context_type, !participants_hide_witnesses);
1225 } else {
1226 return find_witness_anywhere(context_type, !participants_hide_witnesses);
1227 }
1228 }
1229 };
1230
1231 #ifndef PRODUCT
1232 static int deps_find_witness_calls = 0;
1233 static int deps_find_witness_steps = 0;
1234 static int deps_find_witness_recursions = 0;
1235 static int deps_find_witness_singles = 0;
1236 static int deps_find_witness_print = 0; // set to -1 to force a final print
1237 static bool count_find_witness_calls() {
1238 if (TraceDependencies || LogCompilation) {
1239 int pcount = deps_find_witness_print + 1;
1240 bool final_stats = (pcount == 0);
1241 bool initial_call = (pcount == 1);
1242 bool occasional_print = ((pcount & ((1<<10) - 1)) == 0);
1243 if (pcount < 0) pcount = 1; // crude overflow protection
1244 deps_find_witness_print = pcount;
1245 if (VerifyDependencies && initial_call) {
1246 tty->print_cr("Warning: TraceDependencies results may be inflated by VerifyDependencies");
1247 }
1248 if (occasional_print || final_stats) {
1249 // Every now and then dump a little info about dependency searching.
1250 if (xtty != NULL) {
1251 ttyLocker ttyl;
1252 xtty->elem("deps_find_witness calls='%d' steps='%d' recursions='%d' singles='%d'",
1253 deps_find_witness_calls,
1254 deps_find_witness_steps,
1255 deps_find_witness_recursions,
1256 deps_find_witness_singles);
1257 }
1258 if (final_stats || (TraceDependencies && WizardMode)) {
1259 ttyLocker ttyl;
1260 tty->print_cr("Dependency check (find_witness) "
1261 "calls=%d, steps=%d (avg=%.1f), recursions=%d, singles=%d",
1262 deps_find_witness_calls,
1263 deps_find_witness_steps,
1264 (double)deps_find_witness_steps / deps_find_witness_calls,
1265 deps_find_witness_recursions,
1266 deps_find_witness_singles);
1267 }
1268 }
1269 return true;
1270 }
1271 return false;
1272 }
1273 #else
1274 #define count_find_witness_calls() (0)
1275 #endif //PRODUCT
1276
1277
1278 Klass* ClassHierarchyWalker::find_witness_in(KlassDepChange& changes,
1279 Klass* context_type,
1280 bool participants_hide_witnesses) {
1281 assert(changes.involves_context(context_type), "irrelevant dependency");
1282 Klass* new_type = changes.new_type();
1283
1284 (void)count_find_witness_calls();
1285 NOT_PRODUCT(deps_find_witness_singles++);
1286
1287 // Current thread must be in VM (not native mode, as in CI):
1288 assert(must_be_in_vm(), "raw oops here");
1289 // Must not move the class hierarchy during this check:
1290 assert_locked_or_safepoint(Compile_lock);
1291
1292 int nof_impls = InstanceKlass::cast(context_type)->nof_implementors();
1293 if (nof_impls > 1) {
1294 // Avoid this case: *I.m > { A.m, C }; B.m > C
1295 // %%% Until this is fixed more systematically, bail out.
1296 // See corresponding comment in find_witness_anywhere.
1297 return context_type;
1298 }
1299
1300 assert(!is_participant(new_type), "only old classes are participants");
1301 if (participants_hide_witnesses) {
1302 // If the new type is a subtype of a participant, we are done.
1303 for (int i = 0; i < num_participants(); i++) {
1304 Klass* part = participant(i);
1305 if (part == NULL) continue;
1306 assert(changes.involves_context(part) == new_type->is_subtype_of(part),
1307 "correct marking of participants, b/c new_type is unique");
1308 if (changes.involves_context(part)) {
1309 // new guy is protected from this check by previous participant
1310 return NULL;
1311 }
1312 }
1313 }
1314
1315 if (is_witness(new_type) &&
1316 !ignore_witness(new_type)) {
1317 return new_type;
1318 }
1319
1320 return NULL;
1321 }
1322
1323
1324 // Walk hierarchy under a context type, looking for unexpected types.
1325 // Do not report participant types, and recursively walk beneath
1326 // them only if participants_hide_witnesses is false.
1327 // If top_level_call is false, skip testing the context type,
1328 // because the caller has already considered it.
1329 Klass* ClassHierarchyWalker::find_witness_anywhere(Klass* context_type,
1330 bool participants_hide_witnesses,
1331 bool top_level_call) {
1332 // Current thread must be in VM (not native mode, as in CI):
1333 assert(must_be_in_vm(), "raw oops here");
1334 // Must not move the class hierarchy during this check:
1335 assert_locked_or_safepoint(Compile_lock);
1336
1337 bool do_counts = count_find_witness_calls();
1338
1339 // Check the root of the sub-hierarchy first.
1340 if (top_level_call) {
1341 if (do_counts) {
1342 NOT_PRODUCT(deps_find_witness_calls++);
1343 NOT_PRODUCT(deps_find_witness_steps++);
1344 }
1345 if (is_participant(context_type)) {
1346 if (participants_hide_witnesses) return NULL;
1347 // else fall through to search loop...
1348 } else if (is_witness(context_type) && !ignore_witness(context_type)) {
1349 // The context is an abstract class or interface, to start with.
1350 return context_type;
1351 }
1352 }
1353
1354 // Now we must check each implementor and each subclass.
1355 // Use a short worklist to avoid blowing the stack.
1356 // Each worklist entry is a *chain* of subklass siblings to process.
1357 const int CHAINMAX = 100; // >= 1 + InstanceKlass::implementors_limit
1358 Klass* chains[CHAINMAX];
1359 int chaini = 0; // index into worklist
1360 Klass* chain; // scratch variable
1361 #define ADD_SUBCLASS_CHAIN(k) { \
1362 assert(chaini < CHAINMAX, "oob"); \
1363 chain = k->subklass(); \
1364 if (chain != NULL) chains[chaini++] = chain; }
1365
1366 // Look for non-abstract subclasses.
1367 // (Note: Interfaces do not have subclasses.)
1368 ADD_SUBCLASS_CHAIN(context_type);
1369
1370 // If it is an interface, search its direct implementors.
1371 // (Their subclasses are additional indirect implementors.
1372 // See InstanceKlass::add_implementor.)
1373 // (Note: nof_implementors is always zero for non-interfaces.)
1374 if (top_level_call) {
1375 int nof_impls = InstanceKlass::cast(context_type)->nof_implementors();
1376 if (nof_impls > 1) {
1377 // Avoid this case: *I.m > { A.m, C }; B.m > C
1378 // Here, I.m has 2 concrete implementations, but m appears unique
1379 // as A.m, because the search misses B.m when checking C.
1380 // The inherited method B.m was getting missed by the walker
1381 // when interface 'I' was the starting point.
1382 // %%% Until this is fixed more systematically, bail out.
1383 // (Old CHA had the same limitation.)
1384 return context_type;
1385 }
1386 if (nof_impls > 0) {
1387 Klass* impl = InstanceKlass::cast(context_type)->implementor();
1388 assert(impl != NULL, "just checking");
1389 // If impl is the same as the context_type, then more than one
1390 // implementor has seen. No exact info in this case.
1391 if (impl == context_type) {
1392 return context_type; // report an inexact witness to this sad affair
1393 }
1394 if (do_counts)
1395 { NOT_PRODUCT(deps_find_witness_steps++); }
1396 if (is_participant(impl)) {
1397 if (!participants_hide_witnesses) {
1398 ADD_SUBCLASS_CHAIN(impl);
1399 }
1400 } else if (is_witness(impl) && !ignore_witness(impl)) {
1401 return impl;
1402 } else {
1403 ADD_SUBCLASS_CHAIN(impl);
1404 }
1405 }
1406 }
1407
1408 // Recursively process each non-trivial sibling chain.
1409 while (chaini > 0) {
1410 Klass* chain = chains[--chaini];
1411 for (Klass* sub = chain; sub != NULL; sub = sub->next_sibling()) {
1412 if (do_counts) { NOT_PRODUCT(deps_find_witness_steps++); }
1413 if (is_participant(sub)) {
1414 if (participants_hide_witnesses) continue;
1415 // else fall through to process this guy's subclasses
1416 } else if (is_witness(sub) && !ignore_witness(sub)) {
1417 return sub;
1418 }
1419 if (chaini < (VerifyDependencies? 2: CHAINMAX)) {
1420 // Fast path. (Partially disabled if VerifyDependencies.)
1421 ADD_SUBCLASS_CHAIN(sub);
1422 } else {
1423 // Worklist overflow. Do a recursive call. Should be rare.
1424 // The recursive call will have its own worklist, of course.
1425 // (Note that sub has already been tested, so that there is
1426 // no need for the recursive call to re-test. That's handy,
1427 // since the recursive call sees sub as the context_type.)
1428 if (do_counts) { NOT_PRODUCT(deps_find_witness_recursions++); }
1429 Klass* witness = find_witness_anywhere(sub,
1430 participants_hide_witnesses,
1431 /*top_level_call=*/ false);
1432 if (witness != NULL) return witness;
1433 }
1434 }
1435 }
1436
1437 // No witness found. The dependency remains unbroken.
1438 return NULL;
1439 #undef ADD_SUBCLASS_CHAIN
1440 }
1441
1442
1443 bool Dependencies::is_concrete_klass(Klass* k) {
1444 if (k->is_abstract()) return false;
1445 // %%% We could treat classes which are concrete but
1446 // have not yet been instantiated as virtually abstract.
1447 // This would require a deoptimization barrier on first instantiation.
1448 //if (k->is_not_instantiated()) return false;
1449 return true;
1450 }
1451
1452 bool Dependencies::is_concrete_method(Method* m, Klass * k) {
1453 // NULL is not a concrete method,
1454 // statics are irrelevant to virtual call sites,
1455 // abstract methods are not concrete,
1456 // overpass (error) methods are not concrete if k is abstract
1457 //
1458 // note "true" is conservative answer --
1459 // overpass clause is false if k == NULL, implies return true if
1460 // answer depends on overpass clause.
1461 return ! ( m == NULL || m -> is_static() || m -> is_abstract() ||
1462 m->is_overpass() && k != NULL && k -> is_abstract() );
1463 }
1464
1465
1466 Klass* Dependencies::find_finalizable_subclass(Klass* k) {
1467 if (k->is_interface()) return NULL;
1468 if (k->has_finalizer()) return k;
1469 k = k->subklass();
1470 while (k != NULL) {
1471 Klass* result = find_finalizable_subclass(k);
1472 if (result != NULL) return result;
1473 k = k->next_sibling();
1474 }
1475 return NULL;
1476 }
1477
1478
1479 bool Dependencies::is_concrete_klass(ciInstanceKlass* k) {
1480 if (k->is_abstract()) return false;
1481 // We could also return false if k does not yet appear to be
1482 // instantiated, if the VM version supports this distinction also.
1483 //if (k->is_not_instantiated()) return false;
1484 return true;
1485 }
1486
1487 bool Dependencies::has_finalizable_subclass(ciInstanceKlass* k) {
1488 return k->has_finalizable_subclass();
1489 }
1490
1491
1492 // Any use of the contents (bytecodes) of a method must be
1493 // marked by an "evol_method" dependency, if those contents
1494 // can change. (Note: A method is always dependent on itself.)
1495 Klass* Dependencies::check_evol_method(Method* m) {
1496 assert(must_be_in_vm(), "raw oops here");
1497 // Did somebody do a JVMTI RedefineClasses while our backs were turned?
1498 // Or is there a now a breakpoint?
1499 // (Assumes compiled code cannot handle bkpts; change if UseFastBreakpoints.)
1500 if (m->is_old()
1501 || m->number_of_breakpoints() > 0) {
1502 return m->method_holder();
1503 } else {
1504 return NULL;
1505 }
1506 }
1507
1508 // This is a strong assertion: It is that the given type
1509 // has no subtypes whatever. It is most useful for
1510 // optimizing checks on reflected types or on array types.
1511 // (Checks on types which are derived from real instances
1512 // can be optimized more strongly than this, because we
1513 // know that the checked type comes from a concrete type,
1514 // and therefore we can disregard abstract types.)
1515 Klass* Dependencies::check_leaf_type(Klass* ctxk) {
1516 assert(must_be_in_vm(), "raw oops here");
1517 assert_locked_or_safepoint(Compile_lock);
1518 InstanceKlass* ctx = InstanceKlass::cast(ctxk);
1519 Klass* sub = ctx->subklass();
1520 if (sub != NULL) {
1521 return sub;
1522 } else if (ctx->nof_implementors() != 0) {
1523 // if it is an interface, it must be unimplemented
1524 // (if it is not an interface, nof_implementors is always zero)
1525 Klass* impl = ctx->implementor();
1526 assert(impl != NULL, "must be set");
1527 return impl;
1528 } else {
1529 return NULL;
1530 }
1531 }
1532
1533 // Test the assertion that conck is the only concrete subtype* of ctxk.
1534 // The type conck itself is allowed to have have further concrete subtypes.
1535 // This allows the compiler to narrow occurrences of ctxk by conck,
1536 // when dealing with the types of actual instances.
1537 Klass* Dependencies::check_abstract_with_unique_concrete_subtype(Klass* ctxk,
1538 Klass* conck,
1539 KlassDepChange* changes) {
1540 ClassHierarchyWalker wf(conck);
1541 return wf.find_witness_subtype(ctxk, changes);
1542 }
1543
1544 // If a non-concrete class has no concrete subtypes, it is not (yet)
1545 // instantiatable. This can allow the compiler to make some paths go
1546 // dead, if they are gated by a test of the type.
1547 Klass* Dependencies::check_abstract_with_no_concrete_subtype(Klass* ctxk,
1548 KlassDepChange* changes) {
1549 // Find any concrete subtype, with no participants:
1550 ClassHierarchyWalker wf;
1551 return wf.find_witness_subtype(ctxk, changes);
1552 }
1553
1554
1555 // If a concrete class has no concrete subtypes, it can always be
1556 // exactly typed. This allows the use of a cheaper type test.
1557 Klass* Dependencies::check_concrete_with_no_concrete_subtype(Klass* ctxk,
1558 KlassDepChange* changes) {
1559 // Find any concrete subtype, with only the ctxk as participant:
1560 ClassHierarchyWalker wf(ctxk);
1561 return wf.find_witness_subtype(ctxk, changes);
1562 }
1563
1564
1565 // Find the unique concrete proper subtype of ctxk, or NULL if there
1566 // is more than one concrete proper subtype. If there are no concrete
1567 // proper subtypes, return ctxk itself, whether it is concrete or not.
1568 // The returned subtype is allowed to have have further concrete subtypes.
1569 // That is, return CC1 for CX > CC1 > CC2, but NULL for CX > { CC1, CC2 }.
1570 Klass* Dependencies::find_unique_concrete_subtype(Klass* ctxk) {
1571 ClassHierarchyWalker wf(ctxk); // Ignore ctxk when walking.
1572 wf.record_witnesses(1); // Record one other witness when walking.
1573 Klass* wit = wf.find_witness_subtype(ctxk);
1574 if (wit != NULL) return NULL; // Too many witnesses.
1575 Klass* conck = wf.participant(0);
1576 if (conck == NULL) {
1577 #ifndef PRODUCT
1578 // Make sure the dependency mechanism will pass this discovery:
1579 if (VerifyDependencies) {
1580 // Turn off dependency tracing while actually testing deps.
1581 FlagSetting fs(TraceDependencies, false);
1582 if (!Dependencies::is_concrete_klass(ctxk)) {
1583 guarantee(NULL ==
1584 (void *)check_abstract_with_no_concrete_subtype(ctxk),
1585 "verify dep.");
1586 } else {
1587 guarantee(NULL ==
1588 (void *)check_concrete_with_no_concrete_subtype(ctxk),
1589 "verify dep.");
1590 }
1591 }
1592 #endif //PRODUCT
1593 return ctxk; // Return ctxk as a flag for "no subtypes".
1594 } else {
1595 #ifndef PRODUCT
1596 // Make sure the dependency mechanism will pass this discovery:
1597 if (VerifyDependencies) {
1598 // Turn off dependency tracing while actually testing deps.
1599 FlagSetting fs(TraceDependencies, false);
1600 if (!Dependencies::is_concrete_klass(ctxk)) {
1601 guarantee(NULL == (void *)
1602 check_abstract_with_unique_concrete_subtype(ctxk, conck),
1603 "verify dep.");
1604 }
1605 }
1606 #endif //PRODUCT
1607 return conck;
1608 }
1609 }
1610
1611 // Test the assertion that the k[12] are the only concrete subtypes of ctxk,
1612 // except possibly for further subtypes of k[12] themselves.
1613 // The context type must be abstract. The types k1 and k2 are themselves
1614 // allowed to have further concrete subtypes.
1615 Klass* Dependencies::check_abstract_with_exclusive_concrete_subtypes(
1616 Klass* ctxk,
1617 Klass* k1,
1618 Klass* k2,
1619 KlassDepChange* changes) {
1620 ClassHierarchyWalker wf;
1621 wf.add_participant(k1);
1622 wf.add_participant(k2);
1623 return wf.find_witness_subtype(ctxk, changes);
1624 }
1625
1626 // Search ctxk for concrete implementations. If there are klen or fewer,
1627 // pack them into the given array and return the number.
1628 // Otherwise, return -1, meaning the given array would overflow.
1629 // (Note that a return of 0 means there are exactly no concrete subtypes.)
1630 // In this search, if ctxk is concrete, it will be reported alone.
1631 // For any type CC reported, no proper subtypes of CC will be reported.
1632 int Dependencies::find_exclusive_concrete_subtypes(Klass* ctxk,
1633 int klen,
1634 Klass* karray[]) {
1635 ClassHierarchyWalker wf;
1636 wf.record_witnesses(klen);
1637 Klass* wit = wf.find_witness_subtype(ctxk);
1638 if (wit != NULL) return -1; // Too many witnesses.
1639 int num = wf.num_participants();
1640 assert(num <= klen, "oob");
1641 // Pack the result array with the good news.
1642 for (int i = 0; i < num; i++)
1643 karray[i] = wf.participant(i);
1644 #ifndef PRODUCT
1645 // Make sure the dependency mechanism will pass this discovery:
1646 if (VerifyDependencies) {
1647 // Turn off dependency tracing while actually testing deps.
1648 FlagSetting fs(TraceDependencies, false);
1649 switch (Dependencies::is_concrete_klass(ctxk)? -1: num) {
1650 case -1: // ctxk was itself concrete
1651 guarantee(num == 1 && karray[0] == ctxk, "verify dep.");
1652 break;
1653 case 0:
1654 guarantee(NULL == (void *)check_abstract_with_no_concrete_subtype(ctxk),
1655 "verify dep.");
1656 break;
1657 case 1:
1658 guarantee(NULL == (void *)
1659 check_abstract_with_unique_concrete_subtype(ctxk, karray[0]),
1660 "verify dep.");
1661 break;
1662 case 2:
1663 guarantee(NULL == (void *)
1664 check_abstract_with_exclusive_concrete_subtypes(ctxk,
1665 karray[0],
1666 karray[1]),
1667 "verify dep.");
1668 break;
1669 default:
1670 ShouldNotReachHere(); // klen > 2 yet supported
1671 }
1672 }
1673 #endif //PRODUCT
1674 return num;
1675 }
1676
1677 // If a class (or interface) has a unique concrete method uniqm, return NULL.
1678 // Otherwise, return a class that contains an interfering method.
1679 Klass* Dependencies::check_unique_concrete_method(Klass* ctxk, Method* uniqm,
1680 KlassDepChange* changes) {
1681 // Here is a missing optimization: If uniqm->is_final(),
1682 // we don't really need to search beneath it for overrides.
1683 // This is probably not important, since we don't use dependencies
1684 // to track final methods. (They can't be "definalized".)
1685 ClassHierarchyWalker wf(uniqm->method_holder(), uniqm);
1686 return wf.find_witness_definer(ctxk, changes);
1687 }
1688
1689 // Find the set of all non-abstract methods under ctxk that match m.
1690 // (The method m must be defined or inherited in ctxk.)
1691 // Include m itself in the set, unless it is abstract.
1692 // If this set has exactly one element, return that element.
1693 Method* Dependencies::find_unique_concrete_method(Klass* ctxk, Method* m) {
1694 // Return NULL if m is marked old; must have been a redefined method.
1695 if (m->is_old()) {
1696 return NULL;
1697 }
1698 ClassHierarchyWalker wf(m);
1699 assert(wf.check_method_context(ctxk, m), "proper context");
1700 wf.record_witnesses(1);
1701 Klass* wit = wf.find_witness_definer(ctxk);
1702 if (wit != NULL) return NULL; // Too many witnesses.
1703 Method* fm = wf.found_method(0); // Will be NULL if num_parts == 0.
1704 if (Dependencies::is_concrete_method(m, ctxk)) {
1705 if (fm == NULL) {
1706 // It turns out that m was always the only implementation.
1707 fm = m;
1708 } else if (fm != m) {
1709 // Two conflicting implementations after all.
1710 // (This can happen if m is inherited into ctxk and fm overrides it.)
1711 return NULL;
1712 }
1713 }
1714 #ifndef PRODUCT
1715 // Make sure the dependency mechanism will pass this discovery:
1716 if (VerifyDependencies && fm != NULL) {
1717 guarantee(NULL == (void *)check_unique_concrete_method(ctxk, fm),
1718 "verify dep.");
1719 }
1720 #endif //PRODUCT
1721 return fm;
1722 }
1723
1724 Klass* Dependencies::check_exclusive_concrete_methods(Klass* ctxk,
1725 Method* m1,
1726 Method* m2,
1727 KlassDepChange* changes) {
1728 ClassHierarchyWalker wf(m1);
1729 wf.add_participant(m1->method_holder());
1730 wf.add_participant(m2->method_holder());
1731 return wf.find_witness_definer(ctxk, changes);
1732 }
1733
1734 Klass* Dependencies::check_has_no_finalizable_subclasses(Klass* ctxk, KlassDepChange* changes) {
1735 Klass* search_at = ctxk;
1736 if (changes != NULL)
1737 search_at = changes->new_type(); // just look at the new bit
1738 return find_finalizable_subclass(search_at);
1739 }
1740
1741 Klass* Dependencies::check_call_site_target_value(oop call_site, oop method_handle, CallSiteDepChange* changes) {
1742 assert(!oopDesc::is_null(call_site), "sanity");
1743 assert(!oopDesc::is_null(method_handle), "sanity");
1744 assert(call_site->is_a(SystemDictionary::CallSite_klass()), "sanity");
1745
1746 if (changes == NULL) {
1747 // Validate all CallSites
1748 if (java_lang_invoke_CallSite::target(call_site) != method_handle)
1749 return call_site->klass(); // assertion failed
1750 } else {
1751 // Validate the given CallSite
1752 if (call_site == changes->call_site() && java_lang_invoke_CallSite::target(call_site) != changes->method_handle()) {
1753 assert(method_handle != changes->method_handle(), "must be");
1754 return call_site->klass(); // assertion failed
1755 }
1756 }
1757 return NULL; // assertion still valid
1758 }
1759
1760 void Dependencies::DepStream::trace_and_log_witness(Klass* witness) {
1761 if (witness != NULL) {
1762 if (TraceDependencies) {
1763 print_dependency(witness, /*verbose=*/ true);
1764 }
1765 // The following is a no-op unless logging is enabled:
1766 log_dependency(witness);
1767 }
1768 }
1769
1770
1771 Klass* Dependencies::DepStream::check_klass_dependency(KlassDepChange* changes) {
1772 assert_locked_or_safepoint(Compile_lock);
1773 Dependencies::check_valid_dependency_type(type());
1774
1775 Klass* witness = NULL;
1776 switch (type()) {
1777 case evol_method:
1778 witness = check_evol_method(method_argument(0));
1779 break;
1780 case leaf_type:
1781 witness = check_leaf_type(context_type());
1782 break;
1783 case abstract_with_unique_concrete_subtype:
1784 witness = check_abstract_with_unique_concrete_subtype(context_type(), type_argument(1), changes);
1785 break;
1786 case abstract_with_no_concrete_subtype:
1787 witness = check_abstract_with_no_concrete_subtype(context_type(), changes);
1788 break;
1789 case concrete_with_no_concrete_subtype:
1790 witness = check_concrete_with_no_concrete_subtype(context_type(), changes);
1791 break;
1792 case unique_concrete_method:
1793 witness = check_unique_concrete_method(context_type(), method_argument(1), changes);
1794 break;
1795 case abstract_with_exclusive_concrete_subtypes_2:
1796 witness = check_abstract_with_exclusive_concrete_subtypes(context_type(), type_argument(1), type_argument(2), changes);
1797 break;
1798 case exclusive_concrete_methods_2:
1799 witness = check_exclusive_concrete_methods(context_type(), method_argument(1), method_argument(2), changes);
1800 break;
1801 case no_finalizable_subclasses:
1802 witness = check_has_no_finalizable_subclasses(context_type(), changes);
1803 break;
1804 default:
1805 witness = NULL;
1806 break;
1807 }
1808 trace_and_log_witness(witness);
1809 return witness;
1810 }
1811
1812
1813 Klass* Dependencies::DepStream::check_call_site_dependency(CallSiteDepChange* changes) {
1814 assert_locked_or_safepoint(Compile_lock);
1815 Dependencies::check_valid_dependency_type(type());
1816
1817 Klass* witness = NULL;
1818 switch (type()) {
1819 case call_site_target_value:
1820 witness = check_call_site_target_value(argument_oop(0), argument_oop(1), changes);
1821 break;
1822 default:
1823 witness = NULL;
1824 break;
1825 }
1826 trace_and_log_witness(witness);
1827 return witness;
1828 }
1829
1830
1831 Klass* Dependencies::DepStream::spot_check_dependency_at(DepChange& changes) {
1832 // Handle klass dependency
1833 if (changes.is_klass_change() && changes.as_klass_change()->involves_context(context_type()))
1834 return check_klass_dependency(changes.as_klass_change());
1835
1836 // Handle CallSite dependency
1837 if (changes.is_call_site_change())
1838 return check_call_site_dependency(changes.as_call_site_change());
1839
1840 // irrelevant dependency; skip it
1841 return NULL;
1842 }
1843
1844
1845 void DepChange::print() {
1846 int nsup = 0, nint = 0;
1847 for (ContextStream str(*this); str.next(); ) {
1848 Klass* k = str.klass();
1849 switch (str.change_type()) {
1850 case Change_new_type:
1851 tty->print_cr(" dependee = %s", k->external_name());
1852 break;
1853 case Change_new_sub:
1854 if (!WizardMode) {
1855 ++nsup;
1856 } else {
1857 tty->print_cr(" context super = %s", k->external_name());
1858 }
1859 break;
1860 case Change_new_impl:
1861 if (!WizardMode) {
1862 ++nint;
1863 } else {
1864 tty->print_cr(" context interface = %s", k->external_name());
1865 }
1866 break;
1867 }
1868 }
1869 if (nsup + nint != 0) {
1870 tty->print_cr(" context supers = %d, interfaces = %d", nsup, nint);
1871 }
1872 }
1873
1874 void DepChange::ContextStream::start() {
1875 Klass* new_type = _changes.is_klass_change() ? _changes.as_klass_change()->new_type() : (Klass*) NULL;
1876 _change_type = (new_type == NULL ? NO_CHANGE : Start_Klass);
1877 _klass = new_type;
1878 _ti_base = NULL;
1879 _ti_index = 0;
1880 _ti_limit = 0;
1881 }
1882
1883 bool DepChange::ContextStream::next() {
1884 switch (_change_type) {
1885 case Start_Klass: // initial state; _klass is the new type
1886 _ti_base = InstanceKlass::cast(_klass)->transitive_interfaces();
1887 _ti_index = 0;
1888 _change_type = Change_new_type;
1889 return true;
1890 case Change_new_type:
1891 // fall through:
1892 _change_type = Change_new_sub;
1893 case Change_new_sub:
1894 // 6598190: brackets workaround Sun Studio C++ compiler bug 6629277
1895 {
1896 _klass = _klass->super();
1897 if (_klass != NULL) {
1898 return true;
1899 }
1900 }
1901 // else set up _ti_limit and fall through:
1902 _ti_limit = (_ti_base == NULL) ? 0 : _ti_base->length();
1903 _change_type = Change_new_impl;
1904 case Change_new_impl:
1905 if (_ti_index < _ti_limit) {
1906 _klass = _ti_base->at(_ti_index++);
1907 return true;
1908 }
1909 // fall through:
1910 _change_type = NO_CHANGE; // iterator is exhausted
1911 case NO_CHANGE:
1912 break;
1913 default:
1914 ShouldNotReachHere();
1915 }
1916 return false;
1917 }
1918
1919 void KlassDepChange::initialize() {
1920 // entire transaction must be under this lock:
1921 assert_lock_strong(Compile_lock);
1922
1923 // Mark all dependee and all its superclasses
1924 // Mark transitive interfaces
1925 for (ContextStream str(*this); str.next(); ) {
1926 Klass* d = str.klass();
1927 assert(!InstanceKlass::cast(d)->is_marked_dependent(), "checking");
1928 InstanceKlass::cast(d)->set_is_marked_dependent(true);
1929 }
1930 }
1931
1932 KlassDepChange::~KlassDepChange() {
1933 // Unmark all dependee and all its superclasses
1934 // Unmark transitive interfaces
1935 for (ContextStream str(*this); str.next(); ) {
1936 Klass* d = str.klass();
1937 InstanceKlass::cast(d)->set_is_marked_dependent(false);
1938 }
1939 }
1940
1941 bool KlassDepChange::involves_context(Klass* k) {
1942 if (k == NULL || !k->is_instance_klass()) {
1943 return false;
1944 }
1945 InstanceKlass* ik = InstanceKlass::cast(k);
1946 bool is_contained = ik->is_marked_dependent();
1947 assert(is_contained == new_type()->is_subtype_of(k),
1948 "correct marking of potential context types");
1949 return is_contained;
1950 }
1951
1952 #ifndef PRODUCT
1953 void Dependencies::print_statistics() {
1954 if (deps_find_witness_print != 0) {
1955 // Call one final time, to flush out the data.
1956 deps_find_witness_print = -1;
1957 count_find_witness_calls();
1958 }
1959 }
1960 #endif
1961
1962 CallSiteDepChange::CallSiteDepChange(Handle call_site, Handle method_handle) :
1963 _call_site(call_site),
1964 _method_handle(method_handle) {
1965 assert(_call_site()->is_a(SystemDictionary::CallSite_klass()), "must be");
1966 assert(_method_handle.is_null() || _method_handle()->is_a(SystemDictionary::MethodHandle_klass()), "must be");
1967 }