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