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