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