1 /* 2 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "code/compiledIC.hpp" 27 #include "code/scopeDesc.hpp" 28 #include "code/codeCache.hpp" 29 #include "prims/methodHandles.hpp" 30 #include "interpreter/bytecode.hpp" 31 #include "memory/resourceArea.hpp" 32 #include "runtime/mutexLocker.hpp" 33 34 CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, const CodeBlobLayout& layout, int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps, bool caller_must_gc_arguments) 35 : CodeBlob(name, type, layout, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments), 36 _method(method), _mark_for_deoptimization_status(not_marked) { 37 init_defaults(); 38 } 39 40 CompiledMethod::CompiledMethod(Method* method, const char* name, CompilerType type, int size, int header_size, CodeBuffer* cb, int frame_complete_offset, int frame_size, OopMapSet* oop_maps, bool caller_must_gc_arguments) 41 : CodeBlob(name, type, CodeBlobLayout((address) this, size, header_size, cb), cb, frame_complete_offset, frame_size, oop_maps, caller_must_gc_arguments), 42 _method(method), _mark_for_deoptimization_status(not_marked) { 43 init_defaults(); 44 } 45 46 void CompiledMethod::init_defaults() { 47 _has_unsafe_access = 0; 48 _has_method_handle_invokes = 0; 49 _lazy_critical_native = 0; 50 _has_wide_vectors = 0; 51 _unloading_clock = 0; 52 } 53 54 bool CompiledMethod::is_method_handle_return(address return_pc) { 55 if (!has_method_handle_invokes()) return false; 56 PcDesc* pd = pc_desc_at(return_pc); 57 if (pd == NULL) 58 return false; 59 return pd->is_method_handle_invoke(); 60 } 61 62 // When using JVMCI the address might be off by the size of a call instruction. 63 bool CompiledMethod::is_deopt_entry(address pc) { 64 return pc == deopt_handler_begin() 65 #if INCLUDE_JVMCI 66 || (is_compiled_by_jvmci() && pc == (deopt_handler_begin() + NativeCall::instruction_size)) 67 #endif 68 ; 69 } 70 71 // Returns a string version of the method state. 72 const char* CompiledMethod::state() const { 73 int state = get_state(); 74 switch (state) { 75 case in_use: 76 return "in use"; 77 case not_used: 78 return "not_used"; 79 case not_entrant: 80 return "not_entrant"; 81 case zombie: 82 return "zombie"; 83 case unloaded: 84 return "unloaded"; 85 default: 86 fatal("unexpected method state: %d", state); 87 return NULL; 88 } 89 } 90 91 //----------------------------------------------------------------------------- 92 93 void CompiledMethod::add_exception_cache_entry(ExceptionCache* new_entry) { 94 assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock"); 95 assert(new_entry != NULL,"Must be non null"); 96 assert(new_entry->next() == NULL, "Must be null"); 97 98 ExceptionCache *ec = exception_cache(); 99 if (ec != NULL) { 100 new_entry->set_next(ec); 101 } 102 release_set_exception_cache(new_entry); 103 } 104 105 void CompiledMethod::clean_exception_cache(BoolObjectClosure* is_alive) { 106 ExceptionCache* prev = NULL; 107 ExceptionCache* curr = exception_cache(); 108 109 while (curr != NULL) { 110 ExceptionCache* next = curr->next(); 111 112 Klass* ex_klass = curr->exception_type(); 113 if (ex_klass != NULL && !ex_klass->is_loader_alive(is_alive)) { 114 if (prev == NULL) { 115 set_exception_cache(next); 116 } else { 117 prev->set_next(next); 118 } 119 delete curr; 120 // prev stays the same. 121 } else { 122 prev = curr; 123 } 124 125 curr = next; 126 } 127 } 128 129 // public method for accessing the exception cache 130 // These are the public access methods. 131 address CompiledMethod::handler_for_exception_and_pc(Handle exception, address pc) { 132 // We never grab a lock to read the exception cache, so we may 133 // have false negatives. This is okay, as it can only happen during 134 // the first few exception lookups for a given nmethod. 135 ExceptionCache* ec = exception_cache(); 136 while (ec != NULL) { 137 address ret_val; 138 if ((ret_val = ec->match(exception,pc)) != NULL) { 139 return ret_val; 140 } 141 ec = ec->next(); 142 } 143 return NULL; 144 } 145 146 void CompiledMethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) { 147 // There are potential race conditions during exception cache updates, so we 148 // must own the ExceptionCache_lock before doing ANY modifications. Because 149 // we don't lock during reads, it is possible to have several threads attempt 150 // to update the cache with the same data. We need to check for already inserted 151 // copies of the current data before adding it. 152 153 MutexLocker ml(ExceptionCache_lock); 154 ExceptionCache* target_entry = exception_cache_entry_for_exception(exception); 155 156 if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) { 157 target_entry = new ExceptionCache(exception,pc,handler); 158 add_exception_cache_entry(target_entry); 159 } 160 } 161 162 //-------------end of code for ExceptionCache-------------- 163 164 // private method for handling exception cache 165 // These methods are private, and used to manipulate the exception cache 166 // directly. 167 ExceptionCache* CompiledMethod::exception_cache_entry_for_exception(Handle exception) { 168 ExceptionCache* ec = exception_cache(); 169 while (ec != NULL) { 170 if (ec->match_exception_with_space(exception)) { 171 return ec; 172 } 173 ec = ec->next(); 174 } 175 return NULL; 176 } 177 178 bool CompiledMethod::is_at_poll_return(address pc) { 179 RelocIterator iter(this, pc, pc+1); 180 while (iter.next()) { 181 if (iter.type() == relocInfo::poll_return_type) 182 return true; 183 } 184 return false; 185 } 186 187 188 bool CompiledMethod::is_at_poll_or_poll_return(address pc) { 189 RelocIterator iter(this, pc, pc+1); 190 while (iter.next()) { 191 relocInfo::relocType t = iter.type(); 192 if (t == relocInfo::poll_return_type || t == relocInfo::poll_type) 193 return true; 194 } 195 return false; 196 } 197 198 void CompiledMethod::verify_oop_relocations() { 199 // Ensure sure that the code matches the current oop values 200 RelocIterator iter(this, NULL, NULL); 201 while (iter.next()) { 202 if (iter.type() == relocInfo::oop_type) { 203 oop_Relocation* reloc = iter.oop_reloc(); 204 if (!reloc->oop_is_immediate()) { 205 reloc->verify_oop_relocation(); 206 } 207 } 208 } 209 } 210 211 212 ScopeDesc* CompiledMethod::scope_desc_at(address pc) { 213 PcDesc* pd = pc_desc_at(pc); 214 guarantee(pd != NULL, "scope must be present"); 215 return new ScopeDesc(this, pd->scope_decode_offset(), 216 pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(), 217 pd->return_oop()); 218 } 219 220 void CompiledMethod::cleanup_inline_caches(bool clean_all/*=false*/) { 221 assert_locked_or_safepoint(CompiledIC_lock); 222 223 // If the method is not entrant or zombie then a JMP is plastered over the 224 // first few bytes. If an oop in the old code was there, that oop 225 // should not get GC'd. Skip the first few bytes of oops on 226 // not-entrant methods. 227 address low_boundary = verified_entry_point(); 228 if (!is_in_use() && is_nmethod()) { 229 low_boundary += NativeJump::instruction_size; 230 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump. 231 // This means that the low_boundary is going to be a little too high. 232 // This shouldn't matter, since oops of non-entrant methods are never used. 233 // In fact, why are we bothering to look at oops in a non-entrant method?? 234 } 235 236 // Find all calls in an nmethod and clear the ones that point to non-entrant, 237 // zombie and unloaded nmethods. 238 ResourceMark rm; 239 RelocIterator iter(this, low_boundary); 240 while(iter.next()) { 241 switch(iter.type()) { 242 case relocInfo::virtual_call_type: 243 case relocInfo::opt_virtual_call_type: { 244 CompiledIC *ic = CompiledIC_at(&iter); 245 // Ok, to lookup references to zombies here 246 CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination()); 247 if( cb != NULL && cb->is_compiled() ) { 248 CompiledMethod* nm = cb->as_compiled_method(); 249 // Clean inline caches pointing to zombie, non-entrant and unloaded methods 250 if (clean_all || !nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean(is_alive()); 251 } 252 break; 253 } 254 case relocInfo::static_call_type: { 255 CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc()); 256 CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination()); 257 if( cb != NULL && cb->is_compiled() ) { 258 CompiledMethod* cm = cb->as_compiled_method(); 259 // Clean inline caches pointing to zombie, non-entrant and unloaded methods 260 if (clean_all || !cm->is_in_use() || (cm->method()->code() != cm)) { 261 csc->set_to_clean(); 262 } 263 } 264 break; 265 } 266 default: 267 break; 268 } 269 } 270 } 271 272 int CompiledMethod::verify_icholder_relocations() { 273 ResourceMark rm; 274 int count = 0; 275 276 RelocIterator iter(this); 277 while(iter.next()) { 278 if (iter.type() == relocInfo::virtual_call_type) { 279 if (CompiledIC::is_icholder_call_site(iter.virtual_call_reloc(), this)) { 280 CompiledIC *ic = CompiledIC_at(&iter); 281 if (TraceCompiledIC) { 282 tty->print("noticed icholder " INTPTR_FORMAT " ", p2i(ic->cached_icholder())); 283 ic->print(); 284 } 285 assert(ic->cached_icholder() != NULL, "must be non-NULL"); 286 count++; 287 } 288 } 289 } 290 291 return count; 292 } 293 294 // Method that knows how to preserve outgoing arguments at call. This method must be 295 // called with a frame corresponding to a Java invoke 296 void CompiledMethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) { 297 #ifndef SHARK 298 if (method() != NULL && !method()->is_native()) { 299 address pc = fr.pc(); 300 SimpleScopeDesc ssd(this, pc); 301 Bytecode_invoke call(ssd.method(), ssd.bci()); 302 bool has_receiver = call.has_receiver(); 303 bool has_appendix = call.has_appendix(); 304 Symbol* signature = call.signature(); 305 306 // The method attached by JIT-compilers should be used, if present. 307 // Bytecode can be inaccurate in such case. 308 Method* callee = attached_method_before_pc(pc); 309 if (callee != NULL) { 310 has_receiver = !(callee->access_flags().is_static()); 311 has_appendix = false; 312 signature = callee->signature(); 313 } 314 315 fr.oops_compiled_arguments_do(signature, has_receiver, has_appendix, reg_map, f); 316 } 317 #endif // !SHARK 318 } 319 320 // ----------------------------------------------------------------------------- 321 // CompiledMethod::get_deopt_original_pc 322 // 323 // Return the original PC for the given PC if: 324 // (a) the given PC belongs to a nmethod and 325 // (b) it is a deopt PC 326 address CompiledMethod::get_deopt_original_pc(const frame* fr) { 327 if (fr->cb() == NULL) return NULL; 328 329 CompiledMethod* cm = fr->cb()->as_compiled_method_or_null(); 330 if (cm != NULL && cm->is_deopt_pc(fr->pc())) 331 return cm->get_original_pc(fr); 332 333 return NULL; 334 } 335 336 Method* CompiledMethod::attached_method(address call_instr) { 337 assert(code_contains(call_instr), "not part of the nmethod"); 338 RelocIterator iter(this, call_instr, call_instr + 1); 339 while (iter.next()) { 340 if (iter.addr() == call_instr) { 341 switch(iter.type()) { 342 case relocInfo::static_call_type: return iter.static_call_reloc()->method_value(); 343 case relocInfo::opt_virtual_call_type: return iter.opt_virtual_call_reloc()->method_value(); 344 case relocInfo::virtual_call_type: return iter.virtual_call_reloc()->method_value(); 345 default: break; 346 } 347 } 348 } 349 return NULL; // not found 350 } 351 352 Method* CompiledMethod::attached_method_before_pc(address pc) { 353 if (NativeCall::is_call_before(pc)) { 354 NativeCall* ncall = nativeCall_before(pc); 355 return attached_method(ncall->instruction_address()); 356 } 357 return NULL; // not a call 358 } 359 360 void CompiledMethod::clear_inline_caches() { 361 assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint"); 362 if (is_zombie()) { 363 return; 364 } 365 366 RelocIterator iter(this); 367 while (iter.next()) { 368 iter.reloc()->clear_inline_cache(); 369 } 370 } 371 372 // Clear ICStubs of all compiled ICs 373 void CompiledMethod::clear_ic_stubs() { 374 assert_locked_or_safepoint(CompiledIC_lock); 375 RelocIterator iter(this); 376 while(iter.next()) { 377 if (iter.type() == relocInfo::virtual_call_type) { 378 CompiledIC* ic = CompiledIC_at(&iter); 379 ic->clear_ic_stub(); 380 } 381 } 382 } 383 384 #ifdef ASSERT 385 386 class CheckClass : AllStatic { 387 static BoolObjectClosure* _is_alive; 388 389 // Check class_loader is alive for this bit of metadata. 390 static void check_class(Metadata* md) { 391 Klass* klass = NULL; 392 if (md->is_klass()) { 393 klass = ((Klass*)md); 394 } else if (md->is_method()) { 395 klass = ((Method*)md)->method_holder(); 396 } else if (md->is_methodData()) { 397 klass = ((MethodData*)md)->method()->method_holder(); 398 } else { 399 md->print(); 400 ShouldNotReachHere(); 401 } 402 assert(klass->is_loader_alive(_is_alive), "must be alive"); 403 } 404 public: 405 static void do_check_class(BoolObjectClosure* is_alive, CompiledMethod* nm) { 406 assert(SafepointSynchronize::is_at_safepoint(), "this is only ok at safepoint"); 407 _is_alive = is_alive; 408 nm->metadata_do(check_class); 409 } 410 }; 411 412 // This is called during a safepoint so can use static data 413 BoolObjectClosure* CheckClass::_is_alive = NULL; 414 #endif // ASSERT 415 416 417 void CompiledMethod::clean_ic_if_metadata_is_dead(CompiledIC *ic, BoolObjectClosure *is_alive) { 418 if (ic->is_icholder_call()) { 419 // The only exception is compiledICHolder oops which may 420 // yet be marked below. (We check this further below). 421 CompiledICHolder* cichk_oop = ic->cached_icholder(); 422 423 if (cichk_oop->holder_method()->method_holder()->is_loader_alive(is_alive) && 424 cichk_oop->holder_klass()->is_loader_alive(is_alive)) { 425 return; 426 } 427 } else { 428 Metadata* ic_oop = ic->cached_metadata(); 429 if (ic_oop != NULL) { 430 if (ic_oop->is_klass()) { 431 if (((Klass*)ic_oop)->is_loader_alive(is_alive)) { 432 return; 433 } 434 } else if (ic_oop->is_method()) { 435 if (((Method*)ic_oop)->method_holder()->is_loader_alive(is_alive)) { 436 return; 437 } 438 } else { 439 ShouldNotReachHere(); 440 } 441 } 442 } 443 444 ic->set_to_clean(); 445 } 446 447 unsigned char CompiledMethod::_global_unloading_clock = 0; 448 449 void CompiledMethod::increase_unloading_clock() { 450 _global_unloading_clock++; 451 if (_global_unloading_clock == 0) { 452 // _nmethods are allocated with _unloading_clock == 0, 453 // so 0 is never used as a clock value. 454 _global_unloading_clock = 1; 455 } 456 } 457 458 void CompiledMethod::set_unloading_clock(unsigned char unloading_clock) { 459 OrderAccess::release_store((volatile jubyte*)&_unloading_clock, unloading_clock); 460 } 461 462 unsigned char CompiledMethod::unloading_clock() { 463 return (unsigned char)OrderAccess::load_acquire((volatile jubyte*)&_unloading_clock); 464 } 465 466 // Processing of oop references should have been sufficient to keep 467 // all strong references alive. Any weak references should have been 468 // cleared as well. Visit all the metadata and ensure that it's 469 // really alive. 470 void CompiledMethod::verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive) { 471 #ifdef ASSERT 472 RelocIterator iter(this, low_boundary); 473 while (iter.next()) { 474 // static_stub_Relocations may have dangling references to 475 // Method*s so trim them out here. Otherwise it looks like 476 // compiled code is maintaining a link to dead metadata. 477 address static_call_addr = NULL; 478 if (iter.type() == relocInfo::opt_virtual_call_type) { 479 CompiledIC* cic = CompiledIC_at(&iter); 480 if (!cic->is_call_to_interpreted()) { 481 static_call_addr = iter.addr(); 482 } 483 } else if (iter.type() == relocInfo::static_call_type) { 484 CompiledStaticCall* csc = compiledStaticCall_at(iter.reloc()); 485 if (!csc->is_call_to_interpreted()) { 486 static_call_addr = iter.addr(); 487 } 488 } 489 if (static_call_addr != NULL) { 490 RelocIterator sciter(this, low_boundary); 491 while (sciter.next()) { 492 if (sciter.type() == relocInfo::static_stub_type && 493 sciter.static_stub_reloc()->static_call() == static_call_addr) { 494 sciter.static_stub_reloc()->clear_inline_cache(); 495 } 496 } 497 } 498 } 499 // Check that the metadata embedded in the nmethod is alive 500 CheckClass::do_check_class(is_alive, this); 501 #endif 502 } 503 504 // This is called at the end of the strong tracing/marking phase of a 505 // GC to unload an nmethod if it contains otherwise unreachable 506 // oops. 507 508 void CompiledMethod::do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred) { 509 // Make sure the oop's ready to receive visitors 510 assert(!is_zombie() && !is_unloaded(), 511 "should not call follow on zombie or unloaded nmethod"); 512 513 // If the method is not entrant then a JMP is plastered over the 514 // first few bytes. If an oop in the old code was there, that oop 515 // should not get GC'd. Skip the first few bytes of oops on 516 // not-entrant methods. 517 address low_boundary = verified_entry_point(); 518 if (is_not_entrant()) { 519 low_boundary += NativeJump::instruction_size; 520 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump. 521 // (See comment above.) 522 } 523 524 // The RedefineClasses() API can cause the class unloading invariant 525 // to no longer be true. See jvmtiExport.hpp for details. 526 // Also, leave a debugging breadcrumb in local flag. 527 if (JvmtiExport::has_redefined_a_class()) { 528 // This set of the unloading_occurred flag is done before the 529 // call to post_compiled_method_unload() so that the unloading 530 // of this nmethod is reported. 531 unloading_occurred = true; 532 } 533 534 // Exception cache 535 clean_exception_cache(is_alive); 536 537 // If class unloading occurred we first iterate over all inline caches and 538 // clear ICs where the cached oop is referring to an unloaded klass or method. 539 // The remaining live cached oops will be traversed in the relocInfo::oop_type 540 // iteration below. 541 if (unloading_occurred) { 542 RelocIterator iter(this, low_boundary); 543 while(iter.next()) { 544 if (iter.type() == relocInfo::virtual_call_type) { 545 CompiledIC *ic = CompiledIC_at(&iter); 546 clean_ic_if_metadata_is_dead(ic, is_alive); 547 } 548 } 549 } 550 551 if (do_unloading_oops(low_boundary, is_alive, unloading_occurred)) { 552 return; 553 } 554 555 #if INCLUDE_JVMCI 556 if (do_unloading_jvmci(is_alive, unloading_occurred)) { 557 return; 558 } 559 #endif 560 561 // Ensure that all metadata is still alive 562 verify_metadata_loaders(low_boundary, is_alive); 563 } 564 565 template <class CompiledICorStaticCall> 566 static bool clean_if_nmethod_is_unloaded(CompiledICorStaticCall *ic, address addr, BoolObjectClosure *is_alive, CompiledMethod* from) { 567 // Ok, to lookup references to zombies here 568 CodeBlob *cb = CodeCache::find_blob_unsafe(addr); 569 CompiledMethod* nm = (cb != NULL) ? cb->as_compiled_method_or_null() : NULL; 570 if (nm != NULL) { 571 if (nm->unloading_clock() != CompiledMethod::global_unloading_clock()) { 572 // The nmethod has not been processed yet. 573 return true; 574 } 575 576 // Clean inline caches pointing to both zombie and not_entrant methods 577 if (!nm->is_in_use() || (nm->method()->code() != nm)) { 578 ic->set_to_clean(); 579 assert(ic->is_clean(), "nmethod " PTR_FORMAT "not clean %s", p2i(from), from->method()->name_and_sig_as_C_string()); 580 } 581 } 582 583 return false; 584 } 585 586 static bool clean_if_nmethod_is_unloaded(CompiledIC *ic, BoolObjectClosure *is_alive, CompiledMethod* from) { 587 return clean_if_nmethod_is_unloaded(ic, ic->ic_destination(), is_alive, from); 588 } 589 590 static bool clean_if_nmethod_is_unloaded(CompiledStaticCall *csc, BoolObjectClosure *is_alive, CompiledMethod* from) { 591 return clean_if_nmethod_is_unloaded(csc, csc->destination(), is_alive, from); 592 } 593 594 bool CompiledMethod::do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred) { 595 ResourceMark rm; 596 597 // Make sure the oop's ready to receive visitors 598 assert(!is_zombie() && !is_unloaded(), 599 "should not call follow on zombie or unloaded nmethod"); 600 601 // If the method is not entrant then a JMP is plastered over the 602 // first few bytes. If an oop in the old code was there, that oop 603 // should not get GC'd. Skip the first few bytes of oops on 604 // not-entrant methods. 605 address low_boundary = verified_entry_point(); 606 if (is_not_entrant()) { 607 low_boundary += NativeJump::instruction_size; 608 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump. 609 // (See comment above.) 610 } 611 612 // The RedefineClasses() API can cause the class unloading invariant 613 // to no longer be true. See jvmtiExport.hpp for details. 614 // Also, leave a debugging breadcrumb in local flag. 615 if (JvmtiExport::has_redefined_a_class()) { 616 // This set of the unloading_occurred flag is done before the 617 // call to post_compiled_method_unload() so that the unloading 618 // of this nmethod is reported. 619 unloading_occurred = true; 620 } 621 622 // Exception cache 623 clean_exception_cache(is_alive); 624 625 bool postponed = false; 626 627 RelocIterator iter(this, low_boundary); 628 while(iter.next()) { 629 630 switch (iter.type()) { 631 632 case relocInfo::virtual_call_type: 633 if (unloading_occurred) { 634 // If class unloading occurred we first iterate over all inline caches and 635 // clear ICs where the cached oop is referring to an unloaded klass or method. 636 clean_ic_if_metadata_is_dead(CompiledIC_at(&iter), is_alive); 637 } 638 639 postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this); 640 break; 641 642 case relocInfo::opt_virtual_call_type: 643 postponed |= clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this); 644 break; 645 646 case relocInfo::static_call_type: 647 postponed |= clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this); 648 break; 649 650 case relocInfo::oop_type: 651 // handled by do_unloading_oops below 652 break; 653 654 case relocInfo::metadata_type: 655 break; // nothing to do. 656 657 default: 658 break; 659 } 660 } 661 662 if (do_unloading_oops(low_boundary, is_alive, unloading_occurred)) { 663 return postponed; 664 } 665 666 #if INCLUDE_JVMCI 667 if (do_unloading_jvmci(is_alive, unloading_occurred)) { 668 return postponed; 669 } 670 #endif 671 672 // Ensure that all metadata is still alive 673 verify_metadata_loaders(low_boundary, is_alive); 674 675 return postponed; 676 } 677 678 void CompiledMethod::do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred) { 679 ResourceMark rm; 680 681 // Make sure the oop's ready to receive visitors 682 assert(!is_zombie(), 683 "should not call follow on zombie nmethod"); 684 685 // If the method is not entrant then a JMP is plastered over the 686 // first few bytes. If an oop in the old code was there, that oop 687 // should not get GC'd. Skip the first few bytes of oops on 688 // not-entrant methods. 689 address low_boundary = verified_entry_point(); 690 if (is_not_entrant()) { 691 low_boundary += NativeJump::instruction_size; 692 // %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump. 693 // (See comment above.) 694 } 695 696 RelocIterator iter(this, low_boundary); 697 while(iter.next()) { 698 699 switch (iter.type()) { 700 701 case relocInfo::virtual_call_type: 702 clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this); 703 break; 704 705 case relocInfo::opt_virtual_call_type: 706 clean_if_nmethod_is_unloaded(CompiledIC_at(&iter), is_alive, this); 707 break; 708 709 case relocInfo::static_call_type: 710 clean_if_nmethod_is_unloaded(compiledStaticCall_at(iter.reloc()), is_alive, this); 711 break; 712 713 default: 714 break; 715 } 716 } 717 }