1 /*
   2  * Copyright (c) 1997, 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 "jvm.h"
  27 #include "code/codeCache.hpp"
  28 #include "code/compiledIC.hpp"
  29 #include "code/compiledMethod.inline.hpp"
  30 #include "code/dependencies.hpp"
  31 #include "code/nativeInst.hpp"
  32 #include "code/nmethod.hpp"
  33 #include "code/scopeDesc.hpp"
  34 #include "compiler/abstractCompiler.hpp"
  35 #include "compiler/compileBroker.hpp"
  36 #include "compiler/compileLog.hpp"
  37 #include "compiler/compilerDirectives.hpp"
  38 #include "compiler/directivesParser.hpp"
  39 #include "compiler/disassembler.hpp"
  40 #include "interpreter/bytecode.hpp"
  41 #include "logging/log.hpp"
  42 #include "logging/logStream.hpp"
  43 #include "memory/allocation.inline.hpp"
  44 #include "memory/resourceArea.hpp"
  45 #include "oops/access.inline.hpp"
  46 #include "oops/method.inline.hpp"
  47 #include "oops/methodData.hpp"
  48 #include "oops/oop.inline.hpp"
  49 #include "prims/jvmtiImpl.hpp"
  50 #include "runtime/atomic.hpp"
  51 #include "runtime/flags/flagSetting.hpp"
  52 #include "runtime/frame.inline.hpp"
  53 #include "runtime/handles.inline.hpp"
  54 #include "runtime/jniHandles.inline.hpp"
  55 #include "runtime/orderAccess.hpp"
  56 #include "runtime/os.hpp"
  57 #include "runtime/safepointVerifiers.hpp"
  58 #include "runtime/sharedRuntime.hpp"
  59 #include "runtime/sweeper.hpp"
  60 #include "runtime/vmThread.hpp"
  61 #include "utilities/align.hpp"
  62 #include "utilities/dtrace.hpp"
  63 #include "utilities/events.hpp"
  64 #include "utilities/resourceHash.hpp"
  65 #include "utilities/xmlstream.hpp"
  66 #if INCLUDE_JVMCI
  67 #include "jvmci/jvmciJavaClasses.hpp"
  68 #endif
  69 
  70 #ifdef DTRACE_ENABLED
  71 
  72 // Only bother with this argument setup if dtrace is available
  73 
  74 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  75   {                                                                       \
  76     Method* m = (method);                                                 \
  77     if (m != NULL) {                                                      \
  78       Symbol* klass_name = m->klass_name();                               \
  79       Symbol* name = m->name();                                           \
  80       Symbol* signature = m->signature();                                 \
  81       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
  82         (char *) klass_name->bytes(), klass_name->utf8_length(),                   \
  83         (char *) name->bytes(), name->utf8_length(),                               \
  84         (char *) signature->bytes(), signature->utf8_length());                    \
  85     }                                                                     \
  86   }
  87 
  88 #else //  ndef DTRACE_ENABLED
  89 
  90 #define DTRACE_METHOD_UNLOAD_PROBE(method)
  91 
  92 #endif
  93 
  94 //---------------------------------------------------------------------------------
  95 // NMethod statistics
  96 // They are printed under various flags, including:
  97 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
  98 // (In the latter two cases, they like other stats are printed to the log only.)
  99 
 100 #ifndef PRODUCT
 101 // These variables are put into one block to reduce relocations
 102 // and make it simpler to print from the debugger.
 103 struct java_nmethod_stats_struct {
 104   int nmethod_count;
 105   int total_size;
 106   int relocation_size;
 107   int consts_size;
 108   int insts_size;
 109   int stub_size;
 110   int scopes_data_size;
 111   int scopes_pcs_size;
 112   int dependencies_size;
 113   int handler_table_size;
 114   int nul_chk_table_size;
 115   int oops_size;
 116   int metadata_size;
 117 
 118   void note_nmethod(nmethod* nm) {
 119     nmethod_count += 1;
 120     total_size          += nm->size();
 121     relocation_size     += nm->relocation_size();
 122     consts_size         += nm->consts_size();
 123     insts_size          += nm->insts_size();
 124     stub_size           += nm->stub_size();
 125     oops_size           += nm->oops_size();
 126     metadata_size       += nm->metadata_size();
 127     scopes_data_size    += nm->scopes_data_size();
 128     scopes_pcs_size     += nm->scopes_pcs_size();
 129     dependencies_size   += nm->dependencies_size();
 130     handler_table_size  += nm->handler_table_size();
 131     nul_chk_table_size  += nm->nul_chk_table_size();
 132   }
 133   void print_nmethod_stats(const char* name) {
 134     if (nmethod_count == 0)  return;
 135     tty->print_cr("Statistics for %d bytecoded nmethods for %s:", nmethod_count, name);
 136     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
 137     if (nmethod_count != 0)       tty->print_cr(" header         = " SIZE_FORMAT, nmethod_count * sizeof(nmethod));
 138     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
 139     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
 140     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
 141     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
 142     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
 143     if (metadata_size != 0)       tty->print_cr(" metadata       = %d", metadata_size);
 144     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
 145     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
 146     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
 147     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
 148     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
 149   }
 150 };
 151 
 152 struct native_nmethod_stats_struct {
 153   int native_nmethod_count;
 154   int native_total_size;
 155   int native_relocation_size;
 156   int native_insts_size;
 157   int native_oops_size;
 158   int native_metadata_size;
 159   void note_native_nmethod(nmethod* nm) {
 160     native_nmethod_count += 1;
 161     native_total_size       += nm->size();
 162     native_relocation_size  += nm->relocation_size();
 163     native_insts_size       += nm->insts_size();
 164     native_oops_size        += nm->oops_size();
 165     native_metadata_size    += nm->metadata_size();
 166   }
 167   void print_native_nmethod_stats() {
 168     if (native_nmethod_count == 0)  return;
 169     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
 170     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
 171     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
 172     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
 173     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
 174     if (native_metadata_size != 0)    tty->print_cr(" N. metadata    = %d", native_metadata_size);
 175   }
 176 };
 177 
 178 struct pc_nmethod_stats_struct {
 179   int pc_desc_resets;   // number of resets (= number of caches)
 180   int pc_desc_queries;  // queries to nmethod::find_pc_desc
 181   int pc_desc_approx;   // number of those which have approximate true
 182   int pc_desc_repeats;  // number of _pc_descs[0] hits
 183   int pc_desc_hits;     // number of LRU cache hits
 184   int pc_desc_tests;    // total number of PcDesc examinations
 185   int pc_desc_searches; // total number of quasi-binary search steps
 186   int pc_desc_adds;     // number of LUR cache insertions
 187 
 188   void print_pc_stats() {
 189     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
 190                   pc_desc_queries,
 191                   (double)(pc_desc_tests + pc_desc_searches)
 192                   / pc_desc_queries);
 193     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
 194                   pc_desc_resets,
 195                   pc_desc_queries, pc_desc_approx,
 196                   pc_desc_repeats, pc_desc_hits,
 197                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
 198   }
 199 };
 200 
 201 #ifdef COMPILER1
 202 static java_nmethod_stats_struct c1_java_nmethod_stats;
 203 #endif
 204 #ifdef COMPILER2
 205 static java_nmethod_stats_struct c2_java_nmethod_stats;
 206 #endif
 207 #if INCLUDE_JVMCI
 208 static java_nmethod_stats_struct jvmci_java_nmethod_stats;
 209 #endif
 210 static java_nmethod_stats_struct unknown_java_nmethod_stats;
 211 
 212 static native_nmethod_stats_struct native_nmethod_stats;
 213 static pc_nmethod_stats_struct pc_nmethod_stats;
 214 
 215 static void note_java_nmethod(nmethod* nm) {
 216 #ifdef COMPILER1
 217   if (nm->is_compiled_by_c1()) {
 218     c1_java_nmethod_stats.note_nmethod(nm);
 219   } else
 220 #endif
 221 #ifdef COMPILER2
 222   if (nm->is_compiled_by_c2()) {
 223     c2_java_nmethod_stats.note_nmethod(nm);
 224   } else
 225 #endif
 226 #if INCLUDE_JVMCI
 227   if (nm->is_compiled_by_jvmci()) {
 228     jvmci_java_nmethod_stats.note_nmethod(nm);
 229   } else
 230 #endif
 231   {
 232     unknown_java_nmethod_stats.note_nmethod(nm);
 233   }
 234 }
 235 #endif // !PRODUCT
 236 
 237 //---------------------------------------------------------------------------------
 238 
 239 
 240 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 241   assert(pc != NULL, "Must be non null");
 242   assert(exception.not_null(), "Must be non null");
 243   assert(handler != NULL, "Must be non null");
 244 
 245   _count = 0;
 246   _exception_type = exception->klass();
 247   _next = NULL;
 248   _purge_list_next = NULL;
 249 
 250   add_address_and_handler(pc,handler);
 251 }
 252 
 253 
 254 address ExceptionCache::match(Handle exception, address pc) {
 255   assert(pc != NULL,"Must be non null");
 256   assert(exception.not_null(),"Must be non null");
 257   if (exception->klass() == exception_type()) {
 258     return (test_address(pc));
 259   }
 260 
 261   return NULL;
 262 }
 263 
 264 
 265 bool ExceptionCache::match_exception_with_space(Handle exception) {
 266   assert(exception.not_null(),"Must be non null");
 267   if (exception->klass() == exception_type() && count() < cache_size) {
 268     return true;
 269   }
 270   return false;
 271 }
 272 
 273 
 274 address ExceptionCache::test_address(address addr) {
 275   int limit = count();
 276   for (int i = 0; i < limit; i++) {
 277     if (pc_at(i) == addr) {
 278       return handler_at(i);
 279     }
 280   }
 281   return NULL;
 282 }
 283 
 284 
 285 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 286   if (test_address(addr) == handler) return true;
 287 
 288   int index = count();
 289   if (index < cache_size) {
 290     set_pc_at(index, addr);
 291     set_handler_at(index, handler);
 292     increment_count();
 293     return true;
 294   }
 295   return false;
 296 }
 297 
 298 ExceptionCache* ExceptionCache::next() {
 299   return Atomic::load(&_next);
 300 }
 301 
 302 void ExceptionCache::set_next(ExceptionCache *ec) {
 303   Atomic::store(ec, &_next);
 304 }
 305 
 306 //-----------------------------------------------------------------------------
 307 
 308 
 309 // Helper used by both find_pc_desc methods.
 310 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 311   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_tests);
 312   if (!approximate)
 313     return pc->pc_offset() == pc_offset;
 314   else
 315     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 316 }
 317 
 318 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
 319   if (initial_pc_desc == NULL) {
 320     _pc_descs[0] = NULL; // native method; no PcDescs at all
 321     return;
 322   }
 323   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_resets);
 324   // reset the cache by filling it with benign (non-null) values
 325   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
 326   for (int i = 0; i < cache_size; i++)
 327     _pc_descs[i] = initial_pc_desc;
 328 }
 329 
 330 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 331   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_queries);
 332   NOT_PRODUCT(if (approximate) ++pc_nmethod_stats.pc_desc_approx);
 333 
 334   // Note: one might think that caching the most recently
 335   // read value separately would be a win, but one would be
 336   // wrong.  When many threads are updating it, the cache
 337   // line it's in would bounce between caches, negating
 338   // any benefit.
 339 
 340   // In order to prevent race conditions do not load cache elements
 341   // repeatedly, but use a local copy:
 342   PcDesc* res;
 343 
 344   // Step one:  Check the most recently added value.
 345   res = _pc_descs[0];
 346   if (res == NULL) return NULL;  // native method; no PcDescs at all
 347   if (match_desc(res, pc_offset, approximate)) {
 348     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_repeats);
 349     return res;
 350   }
 351 
 352   // Step two:  Check the rest of the LRU cache.
 353   for (int i = 1; i < cache_size; ++i) {
 354     res = _pc_descs[i];
 355     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
 356     if (match_desc(res, pc_offset, approximate)) {
 357       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_hits);
 358       return res;
 359     }
 360   }
 361 
 362   // Report failure.
 363   return NULL;
 364 }
 365 
 366 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 367   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_adds);
 368   // Update the LRU cache by shifting pc_desc forward.
 369   for (int i = 0; i < cache_size; i++)  {
 370     PcDesc* next = _pc_descs[i];
 371     _pc_descs[i] = pc_desc;
 372     pc_desc = next;
 373   }
 374 }
 375 
 376 // adjust pcs_size so that it is a multiple of both oopSize and
 377 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 378 // of oopSize, then 2*sizeof(PcDesc) is)
 379 static int adjust_pcs_size(int pcs_size) {
 380   int nsize = align_up(pcs_size,   oopSize);
 381   if ((nsize % sizeof(PcDesc)) != 0) {
 382     nsize = pcs_size + sizeof(PcDesc);
 383   }
 384   assert((nsize % oopSize) == 0, "correct alignment");
 385   return nsize;
 386 }
 387 
 388 
 389 int nmethod::total_size() const {
 390   return
 391     consts_size()        +
 392     insts_size()         +
 393     stub_size()          +
 394     scopes_data_size()   +
 395     scopes_pcs_size()    +
 396     handler_table_size() +
 397     nul_chk_table_size();
 398 }
 399 
 400 address* nmethod::orig_pc_addr(const frame* fr) {
 401   return (address*) ((address)fr->unextended_sp() + _orig_pc_offset);
 402 }
 403 
 404 const char* nmethod::compile_kind() const {
 405   if (is_osr_method())     return "osr";
 406   if (method() != NULL && is_native_method())  return "c2n";
 407   return NULL;
 408 }
 409 
 410 // Fill in default values for various flag fields
 411 void nmethod::init_defaults() {
 412   _state                      = not_installed;
 413   _has_flushed_dependencies   = 0;
 414   _lock_count                 = 0;
 415   _stack_traversal_mark       = 0;
 416   _unload_reported            = false; // jvmti state
 417   _is_far_code                = false; // nmethods are located in CodeCache
 418 
 419 #ifdef ASSERT
 420   _oops_are_stale             = false;
 421 #endif
 422 
 423   _oops_do_mark_link       = NULL;
 424   _jmethod_id              = NULL;
 425   _osr_link                = NULL;
 426   _scavenge_root_link      = NULL;
 427   _scavenge_root_state     = 0;
 428 #if INCLUDE_RTM_OPT
 429   _rtm_state               = NoRTM;
 430 #endif
 431 #if INCLUDE_JVMCI
 432   _jvmci_installed_code   = NULL;
 433   _speculation_log        = NULL;
 434   _jvmci_installed_code_triggers_invalidation = false;
 435 #endif
 436 }
 437 
 438 nmethod* nmethod::new_native_nmethod(const methodHandle& method,
 439   int compile_id,
 440   CodeBuffer *code_buffer,
 441   int vep_offset,
 442   int frame_complete,
 443   int frame_size,
 444   ByteSize basic_lock_owner_sp_offset,
 445   ByteSize basic_lock_sp_offset,
 446   OopMapSet* oop_maps) {
 447   code_buffer->finalize_oop_references(method);
 448   // create nmethod
 449   nmethod* nm = NULL;
 450   {
 451     MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 452     int native_nmethod_size = CodeBlob::allocation_size(code_buffer, sizeof(nmethod));
 453     CodeOffsets offsets;
 454     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 455     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 456     nm = new (native_nmethod_size, CompLevel_none) nmethod(method(), compiler_none, native_nmethod_size,
 457                                             compile_id, &offsets,
 458                                             code_buffer, frame_size,
 459                                             basic_lock_owner_sp_offset,
 460                                             basic_lock_sp_offset, oop_maps);
 461     NOT_PRODUCT(if (nm != NULL)  native_nmethod_stats.note_native_nmethod(nm));
 462   }
 463 
 464   if (nm != NULL) {
 465     // verify nmethod
 466     debug_only(nm->verify();) // might block
 467 
 468     nm->log_new_nmethod();
 469     nm->make_in_use();
 470   }
 471   return nm;
 472 }
 473 
 474 nmethod* nmethod::new_nmethod(const methodHandle& method,
 475   int compile_id,
 476   int entry_bci,
 477   CodeOffsets* offsets,
 478   int orig_pc_offset,
 479   DebugInformationRecorder* debug_info,
 480   Dependencies* dependencies,
 481   CodeBuffer* code_buffer, int frame_size,
 482   OopMapSet* oop_maps,
 483   ExceptionHandlerTable* handler_table,
 484   ImplicitExceptionTable* nul_chk_table,
 485   AbstractCompiler* compiler,
 486   int comp_level
 487 #if INCLUDE_JVMCI
 488   , jweak installed_code,
 489   jweak speculationLog
 490 #endif
 491 )
 492 {
 493   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 494   code_buffer->finalize_oop_references(method);
 495   // create nmethod
 496   nmethod* nm = NULL;
 497   { MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 498     int nmethod_size =
 499       CodeBlob::allocation_size(code_buffer, sizeof(nmethod))
 500       + adjust_pcs_size(debug_info->pcs_size())
 501       + align_up((int)dependencies->size_in_bytes(), oopSize)
 502       + align_up(handler_table->size_in_bytes()    , oopSize)
 503       + align_up(nul_chk_table->size_in_bytes()    , oopSize)
 504       + align_up(debug_info->data_size()           , oopSize);
 505 
 506     nm = new (nmethod_size, comp_level)
 507     nmethod(method(), compiler->type(), nmethod_size, compile_id, entry_bci, offsets,
 508             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
 509             oop_maps,
 510             handler_table,
 511             nul_chk_table,
 512             compiler,
 513             comp_level
 514 #if INCLUDE_JVMCI
 515             , installed_code,
 516             speculationLog
 517 #endif
 518             );
 519 
 520     if (nm != NULL) {
 521       // To make dependency checking during class loading fast, record
 522       // the nmethod dependencies in the classes it is dependent on.
 523       // This allows the dependency checking code to simply walk the
 524       // class hierarchy above the loaded class, checking only nmethods
 525       // which are dependent on those classes.  The slow way is to
 526       // check every nmethod for dependencies which makes it linear in
 527       // the number of methods compiled.  For applications with a lot
 528       // classes the slow way is too slow.
 529       for (Dependencies::DepStream deps(nm); deps.next(); ) {
 530         if (deps.type() == Dependencies::call_site_target_value) {
 531           // CallSite dependencies are managed on per-CallSite instance basis.
 532           oop call_site = deps.argument_oop(0);
 533           MethodHandles::add_dependent_nmethod(call_site, nm);
 534         } else {
 535           Klass* klass = deps.context_type();
 536           if (klass == NULL) {
 537             continue;  // ignore things like evol_method
 538           }
 539           // record this nmethod as dependent on this klass
 540           InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
 541         }
 542       }
 543       NOT_PRODUCT(if (nm != NULL)  note_java_nmethod(nm));
 544     }
 545   }
 546   // Do verification and logging outside CodeCache_lock.
 547   if (nm != NULL) {
 548     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
 549     DEBUG_ONLY(nm->verify();)
 550     nm->log_new_nmethod();
 551   }
 552   return nm;
 553 }
 554 
 555 // For native wrappers
 556 nmethod::nmethod(
 557   Method* method,
 558   CompilerType type,
 559   int nmethod_size,
 560   int compile_id,
 561   CodeOffsets* offsets,
 562   CodeBuffer* code_buffer,
 563   int frame_size,
 564   ByteSize basic_lock_owner_sp_offset,
 565   ByteSize basic_lock_sp_offset,
 566   OopMapSet* oop_maps )
 567   : CompiledMethod(method, "native nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 568   _is_unloading_state(0),
 569   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
 570   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 571 {
 572   {
 573     int scopes_data_offset = 0;
 574     int deoptimize_offset       = 0;
 575     int deoptimize_mh_offset    = 0;
 576 
 577     debug_only(NoSafepointVerifier nsv;)
 578     assert_locked_or_safepoint(CodeCache_lock);
 579 
 580     init_defaults();
 581     _entry_bci               = InvocationEntryBci;
 582     // We have no exception handler or deopt handler make the
 583     // values something that will never match a pc like the nmethod vtable entry
 584     _exception_offset        = 0;
 585     _orig_pc_offset          = 0;
 586 
 587     _consts_offset           = data_offset();
 588     _stub_offset             = data_offset();
 589     _oops_offset             = data_offset();
 590     _metadata_offset         = _oops_offset         + align_up(code_buffer->total_oop_size(), oopSize);
 591     scopes_data_offset       = _metadata_offset     + align_up(code_buffer->total_metadata_size(), wordSize);
 592     _scopes_pcs_offset       = scopes_data_offset;
 593     _dependencies_offset     = _scopes_pcs_offset;
 594     _handler_table_offset    = _dependencies_offset;
 595     _nul_chk_table_offset    = _handler_table_offset;
 596     _nmethod_end_offset      = _nul_chk_table_offset;
 597     _compile_id              = compile_id;
 598     _comp_level              = CompLevel_none;
 599     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 600     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 601     _osr_entry_point         = NULL;
 602     _exception_cache         = NULL;
 603     _pc_desc_container.reset_to(NULL);
 604     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 605 
 606     _scopes_data_begin = (address) this + scopes_data_offset;
 607     _deopt_handler_begin = (address) this + deoptimize_offset;
 608     _deopt_mh_handler_begin = (address) this + deoptimize_mh_offset;
 609 
 610     code_buffer->copy_code_and_locs_to(this);
 611     code_buffer->copy_values_to(this);
 612 
 613     clear_unloading_state();
 614 
 615     Universe::heap()->register_nmethod(this);
 616     debug_only(Universe::heap()->verify_nmethod(this));
 617 
 618     CodeCache::commit(this);
 619   }
 620 
 621   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 622     ttyLocker ttyl;  // keep the following output all in one block
 623     // This output goes directly to the tty, not the compiler log.
 624     // To enable tools to match it up with the compilation activity,
 625     // be sure to tag this tty output with the compile ID.
 626     if (xtty != NULL) {
 627       xtty->begin_head("print_native_nmethod");
 628       xtty->method(_method);
 629       xtty->stamp();
 630       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 631     }
 632     // print the header part first
 633     print();
 634     // then print the requested information
 635     if (PrintNativeNMethods) {
 636       print_code();
 637       if (oop_maps != NULL) {
 638         oop_maps->print();
 639       }
 640     }
 641     if (PrintRelocations) {
 642       print_relocations();
 643     }
 644     if (xtty != NULL) {
 645       xtty->tail("print_native_nmethod");
 646     }
 647   }
 648 }
 649 
 650 void* nmethod::operator new(size_t size, int nmethod_size, int comp_level) throw () {
 651   return CodeCache::allocate(nmethod_size, CodeCache::get_code_blob_type(comp_level));
 652 }
 653 
 654 nmethod::nmethod(
 655   Method* method,
 656   CompilerType type,
 657   int nmethod_size,
 658   int compile_id,
 659   int entry_bci,
 660   CodeOffsets* offsets,
 661   int orig_pc_offset,
 662   DebugInformationRecorder* debug_info,
 663   Dependencies* dependencies,
 664   CodeBuffer *code_buffer,
 665   int frame_size,
 666   OopMapSet* oop_maps,
 667   ExceptionHandlerTable* handler_table,
 668   ImplicitExceptionTable* nul_chk_table,
 669   AbstractCompiler* compiler,
 670   int comp_level
 671 #if INCLUDE_JVMCI
 672   , jweak installed_code,
 673   jweak speculation_log
 674 #endif
 675   )
 676   : CompiledMethod(method, "nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 677   _is_unloading_state(0),
 678   _native_receiver_sp_offset(in_ByteSize(-1)),
 679   _native_basic_lock_sp_offset(in_ByteSize(-1))
 680 {
 681   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 682   {
 683     debug_only(NoSafepointVerifier nsv;)
 684     assert_locked_or_safepoint(CodeCache_lock);
 685 
 686     _deopt_handler_begin = (address) this;
 687     _deopt_mh_handler_begin = (address) this;
 688 
 689     init_defaults();
 690     _entry_bci               = entry_bci;
 691     _compile_id              = compile_id;
 692     _comp_level              = comp_level;
 693     _orig_pc_offset          = orig_pc_offset;
 694     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 695 
 696     // Section offsets
 697     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
 698     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
 699     set_ctable_begin(header_begin() + _consts_offset);
 700 
 701 #if INCLUDE_JVMCI
 702     _jvmci_installed_code = installed_code;
 703     _speculation_log = speculation_log;
 704     oop obj = JNIHandles::resolve(installed_code);
 705     if (obj == NULL || (obj->is_a(HotSpotNmethod::klass()) && HotSpotNmethod::isDefault(obj))) {
 706       _jvmci_installed_code_triggers_invalidation = false;
 707     } else {
 708       _jvmci_installed_code_triggers_invalidation = true;
 709     }
 710 
 711     if (compiler->is_jvmci()) {
 712       // JVMCI might not produce any stub sections
 713       if (offsets->value(CodeOffsets::Exceptions) != -1) {
 714         _exception_offset        = code_offset()          + offsets->value(CodeOffsets::Exceptions);
 715       } else {
 716         _exception_offset = -1;
 717       }
 718       if (offsets->value(CodeOffsets::Deopt) != -1) {
 719         _deopt_handler_begin       = (address) this + code_offset()          + offsets->value(CodeOffsets::Deopt);
 720       } else {
 721         _deopt_handler_begin = NULL;
 722       }
 723       if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 724         _deopt_mh_handler_begin  = (address) this + code_offset()          + offsets->value(CodeOffsets::DeoptMH);
 725       } else {
 726         _deopt_mh_handler_begin = NULL;
 727       }
 728     } else {
 729 #endif
 730     // Exception handler and deopt handler are in the stub section
 731     assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
 732     assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
 733 
 734     _exception_offset       = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
 735     _deopt_handler_begin    = (address) this + _stub_offset          + offsets->value(CodeOffsets::Deopt);
 736     if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 737       _deopt_mh_handler_begin  = (address) this + _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
 738     } else {
 739       _deopt_mh_handler_begin  = NULL;
 740 #if INCLUDE_JVMCI
 741     }
 742 #endif
 743     }
 744     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
 745       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
 746     } else {
 747       _unwind_handler_offset = -1;
 748     }
 749 
 750     _oops_offset             = data_offset();
 751     _metadata_offset         = _oops_offset          + align_up(code_buffer->total_oop_size(), oopSize);
 752     int scopes_data_offset   = _metadata_offset      + align_up(code_buffer->total_metadata_size(), wordSize);
 753 
 754     _scopes_pcs_offset       = scopes_data_offset    + align_up(debug_info->data_size       (), oopSize);
 755     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
 756     _handler_table_offset    = _dependencies_offset  + align_up((int)dependencies->size_in_bytes (), oopSize);
 757     _nul_chk_table_offset    = _handler_table_offset + align_up(handler_table->size_in_bytes(), oopSize);
 758     _nmethod_end_offset      = _nul_chk_table_offset + align_up(nul_chk_table->size_in_bytes(), oopSize);
 759     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 760     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 761     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
 762     _exception_cache         = NULL;
 763 
 764     _scopes_data_begin = (address) this + scopes_data_offset;
 765 
 766     _pc_desc_container.reset_to(scopes_pcs_begin());
 767 
 768     code_buffer->copy_code_and_locs_to(this);
 769     // Copy contents of ScopeDescRecorder to nmethod
 770     code_buffer->copy_values_to(this);
 771     debug_info->copy_to(this);
 772     dependencies->copy_to(this);
 773     clear_unloading_state();
 774 
 775     Universe::heap()->register_nmethod(this);
 776     debug_only(Universe::heap()->verify_nmethod(this));
 777 
 778     CodeCache::commit(this);
 779 
 780     // Copy contents of ExceptionHandlerTable to nmethod
 781     handler_table->copy_to(this);
 782     nul_chk_table->copy_to(this);
 783 
 784     // we use the information of entry points to find out if a method is
 785     // static or non static
 786     assert(compiler->is_c2() || compiler->is_jvmci() ||
 787            _method->is_static() == (entry_point() == _verified_entry_point),
 788            " entry points must be same for static methods and vice versa");
 789   }
 790 }
 791 
 792 // Print a short set of xml attributes to identify this nmethod.  The
 793 // output should be embedded in some other element.
 794 void nmethod::log_identity(xmlStream* log) const {
 795   log->print(" compile_id='%d'", compile_id());
 796   const char* nm_kind = compile_kind();
 797   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 798   log->print(" compiler='%s'", compiler_name());
 799   if (TieredCompilation) {
 800     log->print(" level='%d'", comp_level());
 801   }
 802 #if INCLUDE_JVMCI
 803     char buffer[O_BUFLEN];
 804     char* jvmci_name = jvmci_installed_code_name(buffer, O_BUFLEN);
 805     if (jvmci_name != NULL) {
 806       log->print(" jvmci_installed_code_name='");
 807       log->text("%s", jvmci_name);
 808       log->print("'");
 809     }
 810 #endif
 811 }
 812 
 813 
 814 #define LOG_OFFSET(log, name)                    \
 815   if (p2i(name##_end()) - p2i(name##_begin())) \
 816     log->print(" " XSTR(name) "_offset='" INTX_FORMAT "'"    , \
 817                p2i(name##_begin()) - p2i(this))
 818 
 819 
 820 void nmethod::log_new_nmethod() const {
 821   if (LogCompilation && xtty != NULL) {
 822     ttyLocker ttyl;
 823     HandleMark hm;
 824     xtty->begin_elem("nmethod");
 825     log_identity(xtty);
 826     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
 827     xtty->print(" address='" INTPTR_FORMAT "'", p2i(this));
 828 
 829     LOG_OFFSET(xtty, relocation);
 830     LOG_OFFSET(xtty, consts);
 831     LOG_OFFSET(xtty, insts);
 832     LOG_OFFSET(xtty, stub);
 833     LOG_OFFSET(xtty, scopes_data);
 834     LOG_OFFSET(xtty, scopes_pcs);
 835     LOG_OFFSET(xtty, dependencies);
 836     LOG_OFFSET(xtty, handler_table);
 837     LOG_OFFSET(xtty, nul_chk_table);
 838     LOG_OFFSET(xtty, oops);
 839     LOG_OFFSET(xtty, metadata);
 840 
 841     xtty->method(method());
 842     xtty->stamp();
 843     xtty->end_elem();
 844   }
 845 }
 846 
 847 #undef LOG_OFFSET
 848 
 849 
 850 // Print out more verbose output usually for a newly created nmethod.
 851 void nmethod::print_on(outputStream* st, const char* msg) const {
 852   if (st != NULL) {
 853     ttyLocker ttyl;
 854     if (WizardMode) {
 855       CompileTask::print(st, this, msg, /*short_form:*/ true);
 856       st->print_cr(" (" INTPTR_FORMAT ")", p2i(this));
 857     } else {
 858       CompileTask::print(st, this, msg, /*short_form:*/ false);
 859     }
 860   }
 861 }
 862 
 863 void nmethod::maybe_print_nmethod(DirectiveSet* directive) {
 864   bool printnmethods = directive->PrintAssemblyOption || directive->PrintNMethodsOption;
 865   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 866     print_nmethod(printnmethods);
 867   }
 868 }
 869 
 870 void nmethod::print_nmethod(bool printmethod) {
 871   ttyLocker ttyl;  // keep the following output all in one block
 872   if (xtty != NULL) {
 873     xtty->begin_head("print_nmethod");
 874     xtty->stamp();
 875     xtty->end_head();
 876   }
 877   // print the header part first
 878   print();
 879   // then print the requested information
 880   if (printmethod) {
 881     print_code();
 882     print_pcs();
 883     if (oop_maps()) {
 884       oop_maps()->print();
 885     }
 886   }
 887   if (printmethod || PrintDebugInfo || CompilerOracle::has_option_string(_method, "PrintDebugInfo")) {
 888     print_scopes();
 889   }
 890   if (printmethod || PrintRelocations || CompilerOracle::has_option_string(_method, "PrintRelocations")) {
 891     print_relocations();
 892   }
 893   if (printmethod || PrintDependencies || CompilerOracle::has_option_string(_method, "PrintDependencies")) {
 894     print_dependencies();
 895   }
 896   if (printmethod || PrintExceptionHandlers) {
 897     print_handler_table();
 898     print_nul_chk_table();
 899   }
 900   if (printmethod) {
 901     print_recorded_oops();
 902     print_recorded_metadata();
 903   }
 904   if (xtty != NULL) {
 905     xtty->tail("print_nmethod");
 906   }
 907 }
 908 
 909 
 910 // Promote one word from an assembly-time handle to a live embedded oop.
 911 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
 912   if (handle == NULL ||
 913       // As a special case, IC oops are initialized to 1 or -1.
 914       handle == (jobject) Universe::non_oop_word()) {
 915     (*dest) = (oop) handle;
 916   } else {
 917     (*dest) = JNIHandles::resolve_non_null(handle);
 918   }
 919 }
 920 
 921 
 922 // Have to have the same name because it's called by a template
 923 void nmethod::copy_values(GrowableArray<jobject>* array) {
 924   int length = array->length();
 925   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
 926   oop* dest = oops_begin();
 927   for (int index = 0 ; index < length; index++) {
 928     initialize_immediate_oop(&dest[index], array->at(index));
 929   }
 930 
 931   // Now we can fix up all the oops in the code.  We need to do this
 932   // in the code because the assembler uses jobjects as placeholders.
 933   // The code and relocations have already been initialized by the
 934   // CodeBlob constructor, so it is valid even at this early point to
 935   // iterate over relocations and patch the code.
 936   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
 937 }
 938 
 939 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
 940   int length = array->length();
 941   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
 942   Metadata** dest = metadata_begin();
 943   for (int index = 0 ; index < length; index++) {
 944     dest[index] = array->at(index);
 945   }
 946 }
 947 
 948 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
 949   // re-patch all oop-bearing instructions, just in case some oops moved
 950   RelocIterator iter(this, begin, end);
 951   while (iter.next()) {
 952     if (iter.type() == relocInfo::oop_type) {
 953       oop_Relocation* reloc = iter.oop_reloc();
 954       if (initialize_immediates && reloc->oop_is_immediate()) {
 955         oop* dest = reloc->oop_addr();
 956         initialize_immediate_oop(dest, (jobject) *dest);
 957       }
 958       // Refresh the oop-related bits of this instruction.
 959       reloc->fix_oop_relocation();
 960     } else if (iter.type() == relocInfo::metadata_type) {
 961       metadata_Relocation* reloc = iter.metadata_reloc();
 962       reloc->fix_metadata_relocation();
 963     }
 964   }
 965 }
 966 
 967 
 968 void nmethod::verify_clean_inline_caches() {
 969   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
 970 
 971   ResourceMark rm;
 972   RelocIterator iter(this, oops_reloc_begin());
 973   while(iter.next()) {
 974     switch(iter.type()) {
 975       case relocInfo::virtual_call_type:
 976       case relocInfo::opt_virtual_call_type: {
 977         CompiledIC *ic = CompiledIC_at(&iter);
 978         // Ok, to lookup references to zombies here
 979         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
 980         assert(cb != NULL, "destination not in CodeBlob?");
 981         nmethod* nm = cb->as_nmethod_or_null();
 982         if( nm != NULL ) {
 983           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 984           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 985             assert(ic->is_clean(), "IC should be clean");
 986           }
 987         }
 988         break;
 989       }
 990       case relocInfo::static_call_type: {
 991         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
 992         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
 993         assert(cb != NULL, "destination not in CodeBlob?");
 994         nmethod* nm = cb->as_nmethod_or_null();
 995         if( nm != NULL ) {
 996           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 997           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 998             assert(csc->is_clean(), "IC should be clean");
 999           }
1000         }
1001         break;
1002       }
1003       default:
1004         break;
1005     }
1006   }
1007 }
1008 
1009 // This is a private interface with the sweeper.
1010 void nmethod::mark_as_seen_on_stack() {
1011   assert(is_alive(), "Must be an alive method");
1012   // Set the traversal mark to ensure that the sweeper does 2
1013   // cleaning passes before moving to zombie.
1014   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1015 }
1016 
1017 // Tell if a non-entrant method can be converted to a zombie (i.e.,
1018 // there are no activations on the stack, not in use by the VM,
1019 // and not in use by the ServiceThread)
1020 bool nmethod::can_convert_to_zombie() {
1021   // Note that this is called when the sweeper has observed the nmethod to be
1022   // not_entrant. However, with concurrent code cache unloading, the state
1023   // might have moved on to unloaded if it is_unloading(), due to racing
1024   // concurrent GC threads.
1025   assert(is_not_entrant() || is_unloading(), "must be a non-entrant method");
1026 
1027   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1028   // count can be greater than the stack traversal count before it hits the
1029   // nmethod for the second time.
1030   // If an is_unloading() nmethod is still not_entrant, then it is not safe to
1031   // convert it to zombie due to GC unloading interactions. However, if it
1032   // has become unloaded, then it is okay to convert such nmethods to zombie.
1033   return stack_traversal_mark() + 1 < NMethodSweeper::traversal_count() &&
1034          !is_locked_by_vm() && (!is_unloading() || is_unloaded());
1035 }
1036 
1037 void nmethod::inc_decompile_count() {
1038   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
1039   // Could be gated by ProfileTraps, but do not bother...
1040   Method* m = method();
1041   if (m == NULL)  return;
1042   MethodData* mdo = m->method_data();
1043   if (mdo == NULL)  return;
1044   // There is a benign race here.  See comments in methodData.hpp.
1045   mdo->inc_decompile_count();
1046 }
1047 
1048 void nmethod::make_unloaded() {
1049   post_compiled_method_unload();
1050 
1051   // This nmethod is being unloaded, make sure that dependencies
1052   // recorded in instanceKlasses get flushed.
1053   // Since this work is being done during a GC, defer deleting dependencies from the
1054   // InstanceKlass.
1055   assert(Universe::heap()->is_gc_active() || Thread::current()->is_ConcurrentGC_thread(),
1056          "should only be called during gc");
1057   flush_dependencies(/*delete_immediately*/false);
1058 
1059   // Break cycle between nmethod & method
1060   LogTarget(Trace, class, unload, nmethod) lt;
1061   if (lt.is_enabled()) {
1062     LogStream ls(lt);
1063     ls.print("making nmethod " INTPTR_FORMAT
1064              " unloadable, Method*(" INTPTR_FORMAT
1065              ") ",
1066              p2i(this), p2i(_method));
1067      ls.cr();
1068   }
1069   // Unlink the osr method, so we do not look this up again
1070   if (is_osr_method()) {
1071     // Invalidate the osr nmethod only once
1072     if (is_in_use()) {
1073       invalidate_osr_method();
1074     }
1075 #ifdef ASSERT
1076     if (method() != NULL) {
1077       // Make sure osr nmethod is invalidated, i.e. not on the list
1078       bool found = method()->method_holder()->remove_osr_nmethod(this);
1079       assert(!found, "osr nmethod should have been invalidated");
1080     }
1081 #endif
1082   }
1083 
1084   // If _method is already NULL the Method* is about to be unloaded,
1085   // so we don't have to break the cycle. Note that it is possible to
1086   // have the Method* live here, in case we unload the nmethod because
1087   // it is pointing to some oop (other than the Method*) being unloaded.
1088   if (_method != NULL) {
1089     // OSR methods point to the Method*, but the Method* does not
1090     // point back!
1091     if (_method->code() == this) {
1092       _method->clear_code(); // Break a cycle
1093     }
1094     _method = NULL;            // Clear the method of this dead nmethod
1095   }
1096 
1097   // Make the class unloaded - i.e., change state and notify sweeper
1098   assert(SafepointSynchronize::is_at_safepoint() || Thread::current()->is_ConcurrentGC_thread(),
1099          "must be at safepoint");
1100 
1101   {
1102     // Clear ICStubs and release any CompiledICHolders.
1103     CompiledICLocker ml(this);
1104     clear_ic_callsites();
1105   }
1106 
1107   // Unregister must be done before the state change
1108   {
1109     MutexLockerEx ml(SafepointSynchronize::is_at_safepoint() ? NULL : CodeCache_lock,
1110                      Mutex::_no_safepoint_check_flag);
1111     Universe::heap()->unregister_nmethod(this);
1112   }
1113 
1114   // Log the unloading.
1115   log_state_change();
1116 
1117 #if INCLUDE_JVMCI
1118   // The method can only be unloaded after the pointer to the installed code
1119   // Java wrapper is no longer alive. Here we need to clear out this weak
1120   // reference to the dead object.
1121   maybe_invalidate_installed_code();
1122 #endif
1123 
1124   // The Method* is gone at this point
1125   assert(_method == NULL, "Tautology");
1126 
1127   set_osr_link(NULL);
1128   NMethodSweeper::report_state_change(this);
1129 
1130   // The release is only needed for compile-time ordering, as accesses
1131   // into the nmethod after the store are not safe due to the sweeper
1132   // being allowed to free it when the store is observed, during
1133   // concurrent nmethod unloading. Therefore, there is no need for
1134   // acquire on the loader side.
1135   OrderAccess::release_store(&_state, (signed char)unloaded);
1136 }
1137 
1138 void nmethod::invalidate_osr_method() {
1139   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1140   // Remove from list of active nmethods
1141   if (method() != NULL) {
1142     method()->method_holder()->remove_osr_nmethod(this);
1143   }
1144 }
1145 
1146 void nmethod::log_state_change() const {
1147   if (LogCompilation) {
1148     if (xtty != NULL) {
1149       ttyLocker ttyl;  // keep the following output all in one block
1150       if (_state == unloaded) {
1151         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1152                          os::current_thread_id());
1153       } else {
1154         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1155                          os::current_thread_id(),
1156                          (_state == zombie ? " zombie='1'" : ""));
1157       }
1158       log_identity(xtty);
1159       xtty->stamp();
1160       xtty->end_elem();
1161     }
1162   }
1163 
1164   const char *state_msg = _state == zombie ? "made zombie" : "made not entrant";
1165   CompileTask::print_ul(this, state_msg);
1166   if (PrintCompilation && _state != unloaded) {
1167     print_on(tty, state_msg);
1168   }
1169 }
1170 
1171 void nmethod::unlink_from_method(bool acquire_lock) {
1172   // We need to check if both the _code and _from_compiled_code_entry_point
1173   // refer to this nmethod because there is a race in setting these two fields
1174   // in Method* as seen in bugid 4947125.
1175   // If the vep() points to the zombie nmethod, the memory for the nmethod
1176   // could be flushed and the compiler and vtable stubs could still call
1177   // through it.
1178   if (method() != NULL && (method()->code() == this ||
1179                            method()->from_compiled_entry() == verified_entry_point())) {
1180     method()->clear_code(acquire_lock);
1181   }
1182 }
1183 
1184 /**
1185  * Common functionality for both make_not_entrant and make_zombie
1186  */
1187 bool nmethod::make_not_entrant_or_zombie(int state) {
1188   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1189   assert(!is_zombie(), "should not already be a zombie");
1190 
1191   if (_state == state) {
1192     // Avoid taking the lock if already in required state.
1193     // This is safe from races because the state is an end-state,
1194     // which the nmethod cannot back out of once entered.
1195     // No need for fencing either.
1196     return false;
1197   }
1198 
1199   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1200   nmethodLocker nml(this);
1201   methodHandle the_method(method());
1202   // This can be called while the system is already at a safepoint which is ok
1203   NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());
1204 
1205   // during patching, depending on the nmethod state we must notify the GC that
1206   // code has been unloaded, unregistering it. We cannot do this right while
1207   // holding the Patching_lock because we need to use the CodeCache_lock. This
1208   // would be prone to deadlocks.
1209   // This flag is used to remember whether we need to later lock and unregister.
1210   bool nmethod_needs_unregister = false;
1211 
1212   {
1213     // invalidate osr nmethod before acquiring the patching lock since
1214     // they both acquire leaf locks and we don't want a deadlock.
1215     // This logic is equivalent to the logic below for patching the
1216     // verified entry point of regular methods. We check that the
1217     // nmethod is in use to ensure that it is invalidated only once.
1218     if (is_osr_method() && is_in_use()) {
1219       // this effectively makes the osr nmethod not entrant
1220       invalidate_osr_method();
1221     }
1222 
1223     // Enter critical section.  Does not block for safepoint.
1224     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1225 
1226     if (_state == state) {
1227       // another thread already performed this transition so nothing
1228       // to do, but return false to indicate this.
1229       return false;
1230     }
1231 
1232     // The caller can be calling the method statically or through an inline
1233     // cache call.
1234     if (!is_osr_method() && !is_not_entrant()) {
1235       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1236                   SharedRuntime::get_handle_wrong_method_stub());
1237     }
1238 
1239     if (is_in_use() && update_recompile_counts()) {
1240       // It's a true state change, so mark the method as decompiled.
1241       // Do it only for transition from alive.
1242       inc_decompile_count();
1243     }
1244 
1245     // If the state is becoming a zombie, signal to unregister the nmethod with
1246     // the heap.
1247     // This nmethod may have already been unloaded during a full GC.
1248     if ((state == zombie) && !is_unloaded()) {
1249       nmethod_needs_unregister = true;
1250     }
1251 
1252     // Must happen before state change. Otherwise we have a race condition in
1253     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
1254     // transition its state from 'not_entrant' to 'zombie' without having to wait
1255     // for stack scanning.
1256     if (state == not_entrant) {
1257       mark_as_seen_on_stack();
1258       OrderAccess::storestore(); // _stack_traversal_mark and _state
1259     }
1260 
1261     // Change state
1262     _state = state;
1263 
1264     // Log the transition once
1265     log_state_change();
1266 
1267     // Invalidate while holding the patching lock
1268     JVMCI_ONLY(maybe_invalidate_installed_code());
1269 
1270     // Remove nmethod from method.
1271     unlink_from_method(false /* already owns Patching_lock */);
1272   } // leave critical region under Patching_lock
1273 
1274 #ifdef ASSERT
1275   if (is_osr_method() && method() != NULL) {
1276     // Make sure osr nmethod is invalidated, i.e. not on the list
1277     bool found = method()->method_holder()->remove_osr_nmethod(this);
1278     assert(!found, "osr nmethod should have been invalidated");
1279   }
1280 #endif
1281 
1282   // When the nmethod becomes zombie it is no longer alive so the
1283   // dependencies must be flushed.  nmethods in the not_entrant
1284   // state will be flushed later when the transition to zombie
1285   // happens or they get unloaded.
1286   if (state == zombie) {
1287     {
1288       // Flushing dependencies must be done before any possible
1289       // safepoint can sneak in, otherwise the oops used by the
1290       // dependency logic could have become stale.
1291       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1292       if (nmethod_needs_unregister) {
1293         Universe::heap()->unregister_nmethod(this);
1294       }
1295       flush_dependencies(/*delete_immediately*/true);
1296     }
1297 
1298     // Clear ICStubs to prevent back patching stubs of zombie or flushed
1299     // nmethods during the next safepoint (see ICStub::finalize), as well
1300     // as to free up CompiledICHolder resources.
1301     {
1302       CompiledICLocker ml(this);
1303       clear_ic_callsites();
1304     }
1305 
1306     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1307     // event and it hasn't already been reported for this nmethod then
1308     // report it now. The event may have been reported earlier if the GC
1309     // marked it for unloading). JvmtiDeferredEventQueue support means
1310     // we no longer go to a safepoint here.
1311     post_compiled_method_unload();
1312 
1313 #ifdef ASSERT
1314     // It's no longer safe to access the oops section since zombie
1315     // nmethods aren't scanned for GC.
1316     _oops_are_stale = true;
1317 #endif
1318      // the Method may be reclaimed by class unloading now that the
1319      // nmethod is in zombie state
1320     set_method(NULL);
1321   } else {
1322     assert(state == not_entrant, "other cases may need to be handled differently");
1323   }
1324 
1325   if (TraceCreateZombies) {
1326     ResourceMark m;
1327     tty->print_cr("nmethod <" INTPTR_FORMAT "> %s code made %s", p2i(this), this->method() ? this->method()->name_and_sig_as_C_string() : "null", (state == not_entrant) ? "not entrant" : "zombie");
1328   }
1329 
1330   NMethodSweeper::report_state_change(this);
1331   return true;
1332 }
1333 
1334 void nmethod::flush() {
1335   MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1336   // Note that there are no valid oops in the nmethod anymore.
1337   assert(!is_osr_method() || is_unloaded() || is_zombie(),
1338          "osr nmethod must be unloaded or zombie before flushing");
1339   assert(is_zombie() || is_osr_method(), "must be a zombie method");
1340   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1341   assert_locked_or_safepoint(CodeCache_lock);
1342 
1343   // completely deallocate this method
1344   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, p2i(this));
1345   if (PrintMethodFlushing) {
1346     tty->print_cr("*flushing %s nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT
1347                   "/Free CodeCache:" SIZE_FORMAT "Kb",
1348                   is_osr_method() ? "osr" : "",_compile_id, p2i(this), CodeCache::blob_count(),
1349                   CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024);
1350   }
1351 
1352   // We need to deallocate any ExceptionCache data.
1353   // Note that we do not need to grab the nmethod lock for this, it
1354   // better be thread safe if we're disposing of it!
1355   ExceptionCache* ec = exception_cache();
1356   set_exception_cache(NULL);
1357   while(ec != NULL) {
1358     ExceptionCache* next = ec->next();
1359     delete ec;
1360     ec = next;
1361   }
1362 
1363   if (on_scavenge_root_list()) {
1364     CodeCache::drop_scavenge_root_nmethod(this);
1365   }
1366 
1367 #if INCLUDE_JVMCI
1368   assert(_jvmci_installed_code == NULL, "should have been nulled out when transitioned to zombie");
1369   assert(_speculation_log == NULL, "should have been nulled out when transitioned to zombie");
1370 #endif
1371 
1372   Universe::heap()->flush_nmethod(this);
1373 
1374   CodeBlob::flush();
1375   CodeCache::free(this);
1376 }
1377 
1378 oop nmethod::oop_at(int index) const {
1379   if (index == 0) {
1380     return NULL;
1381   }
1382   return NativeAccess<AS_NO_KEEPALIVE>::oop_load(oop_addr_at(index));
1383 }
1384 
1385 //
1386 // Notify all classes this nmethod is dependent on that it is no
1387 // longer dependent. This should only be called in two situations.
1388 // First, when a nmethod transitions to a zombie all dependents need
1389 // to be clear.  Since zombification happens at a safepoint there's no
1390 // synchronization issues.  The second place is a little more tricky.
1391 // During phase 1 of mark sweep class unloading may happen and as a
1392 // result some nmethods may get unloaded.  In this case the flushing
1393 // of dependencies must happen during phase 1 since after GC any
1394 // dependencies in the unloaded nmethod won't be updated, so
1395 // traversing the dependency information in unsafe.  In that case this
1396 // function is called with a boolean argument and this function only
1397 // notifies instanceKlasses that are reachable
1398 
1399 void nmethod::flush_dependencies(bool delete_immediately) {
1400   DEBUG_ONLY(bool called_by_gc = Universe::heap()->is_gc_active() || Thread::current()->is_ConcurrentGC_thread();)
1401   assert(called_by_gc != delete_immediately,
1402   "delete_immediately is false if and only if we are called during GC");
1403   if (!has_flushed_dependencies()) {
1404     set_has_flushed_dependencies();
1405     for (Dependencies::DepStream deps(this); deps.next(); ) {
1406       if (deps.type() == Dependencies::call_site_target_value) {
1407         // CallSite dependencies are managed on per-CallSite instance basis.
1408         oop call_site = deps.argument_oop(0);
1409         if (delete_immediately) {
1410           assert_locked_or_safepoint(CodeCache_lock);
1411           MethodHandles::remove_dependent_nmethod(call_site, this);
1412         } else {
1413           MethodHandles::clean_dependency_context(call_site);
1414         }
1415       } else {
1416         Klass* klass = deps.context_type();
1417         if (klass == NULL) {
1418           continue;  // ignore things like evol_method
1419         }
1420         // During GC delete_immediately is false, and liveness
1421         // of dependee determines class that needs to be updated.
1422         if (delete_immediately) {
1423           assert_locked_or_safepoint(CodeCache_lock);
1424           InstanceKlass::cast(klass)->remove_dependent_nmethod(this);
1425         } else if (klass->is_loader_alive()) {
1426           // The GC may clean dependency contexts concurrently and in parallel.
1427           InstanceKlass::cast(klass)->clean_dependency_context();
1428         }
1429       }
1430     }
1431   }
1432 }
1433 
1434 // ------------------------------------------------------------------
1435 // post_compiled_method_load_event
1436 // new method for install_code() path
1437 // Transfer information from compilation to jvmti
1438 void nmethod::post_compiled_method_load_event() {
1439 
1440   Method* moop = method();
1441   HOTSPOT_COMPILED_METHOD_LOAD(
1442       (char *) moop->klass_name()->bytes(),
1443       moop->klass_name()->utf8_length(),
1444       (char *) moop->name()->bytes(),
1445       moop->name()->utf8_length(),
1446       (char *) moop->signature()->bytes(),
1447       moop->signature()->utf8_length(),
1448       insts_begin(), insts_size());
1449 
1450   if (JvmtiExport::should_post_compiled_method_load() ||
1451       JvmtiExport::should_post_compiled_method_unload()) {
1452     get_and_cache_jmethod_id();
1453   }
1454 
1455   if (JvmtiExport::should_post_compiled_method_load()) {
1456     // Let the Service thread (which is a real Java thread) post the event
1457     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1458     JvmtiDeferredEventQueue::enqueue(
1459       JvmtiDeferredEvent::compiled_method_load_event(this));
1460   }
1461 }
1462 
1463 jmethodID nmethod::get_and_cache_jmethod_id() {
1464   if (_jmethod_id == NULL) {
1465     // Cache the jmethod_id since it can no longer be looked up once the
1466     // method itself has been marked for unloading.
1467     _jmethod_id = method()->jmethod_id();
1468   }
1469   return _jmethod_id;
1470 }
1471 
1472 void nmethod::post_compiled_method_unload() {
1473   if (unload_reported()) {
1474     // During unloading we transition to unloaded and then to zombie
1475     // and the unloading is reported during the first transition.
1476     return;
1477   }
1478 
1479   assert(_method != NULL && !is_unloaded(), "just checking");
1480   DTRACE_METHOD_UNLOAD_PROBE(method());
1481 
1482   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1483   // post the event. Sometime later this nmethod will be made a zombie
1484   // by the sweeper but the Method* will not be valid at that point.
1485   // If the _jmethod_id is null then no load event was ever requested
1486   // so don't bother posting the unload.  The main reason for this is
1487   // that the jmethodID is a weak reference to the Method* so if
1488   // it's being unloaded there's no way to look it up since the weak
1489   // ref will have been cleared.
1490   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1491     assert(!unload_reported(), "already unloaded");
1492     JvmtiDeferredEvent event =
1493       JvmtiDeferredEvent::compiled_method_unload_event(this,
1494           _jmethod_id, insts_begin());
1495     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1496     JvmtiDeferredEventQueue::enqueue(event);
1497   }
1498 
1499   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1500   // any time. As the nmethod is being unloaded now we mark it has
1501   // having the unload event reported - this will ensure that we don't
1502   // attempt to report the event in the unlikely scenario where the
1503   // event is enabled at the time the nmethod is made a zombie.
1504   set_unload_reported();
1505 }
1506 
1507 // Iterate over metadata calling this function.   Used by RedefineClasses
1508 void nmethod::metadata_do(void f(Metadata*)) {
1509   {
1510     // Visit all immediate references that are embedded in the instruction stream.
1511     RelocIterator iter(this, oops_reloc_begin());
1512     while (iter.next()) {
1513       if (iter.type() == relocInfo::metadata_type ) {
1514         metadata_Relocation* r = iter.metadata_reloc();
1515         // In this metadata, we must only follow those metadatas directly embedded in
1516         // the code.  Other metadatas (oop_index>0) are seen as part of
1517         // the metadata section below.
1518         assert(1 == (r->metadata_is_immediate()) +
1519                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
1520                "metadata must be found in exactly one place");
1521         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
1522           Metadata* md = r->metadata_value();
1523           if (md != _method) f(md);
1524         }
1525       } else if (iter.type() == relocInfo::virtual_call_type) {
1526         // Check compiledIC holders associated with this nmethod
1527         ResourceMark rm;
1528         CompiledIC *ic = CompiledIC_at(&iter);
1529         if (ic->is_icholder_call()) {
1530           CompiledICHolder* cichk = ic->cached_icholder();
1531           f(cichk->holder_metadata());
1532           f(cichk->holder_klass());
1533         } else {
1534           Metadata* ic_oop = ic->cached_metadata();
1535           if (ic_oop != NULL) {
1536             f(ic_oop);
1537           }
1538         }
1539       }
1540     }
1541   }
1542 
1543   // Visit the metadata section
1544   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
1545     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
1546     Metadata* md = *p;
1547     f(md);
1548   }
1549 
1550   // Visit metadata not embedded in the other places.
1551   if (_method != NULL) f(_method);
1552 }
1553 
1554 // The _is_unloading_state encodes a tuple comprising the unloading cycle
1555 // and the result of IsUnloadingBehaviour::is_unloading() fpr that cycle.
1556 // This is the bit layout of the _is_unloading_state byte: 00000CCU
1557 // CC refers to the cycle, which has 2 bits, and U refers to the result of
1558 // IsUnloadingBehaviour::is_unloading() for that unloading cycle.
1559 
1560 class IsUnloadingState: public AllStatic {
1561   static const uint8_t _is_unloading_mask = 1;
1562   static const uint8_t _is_unloading_shift = 0;
1563   static const uint8_t _unloading_cycle_mask = 6;
1564   static const uint8_t _unloading_cycle_shift = 1;
1565 
1566   static uint8_t set_is_unloading(uint8_t state, bool value) {
1567     state &= ~_is_unloading_mask;
1568     if (value) {
1569       state |= 1 << _is_unloading_shift;
1570     }
1571     assert(is_unloading(state) == value, "unexpected unloading cycle overflow");
1572     return state;
1573   }
1574 
1575   static uint8_t set_unloading_cycle(uint8_t state, uint8_t value) {
1576     state &= ~_unloading_cycle_mask;
1577     state |= value << _unloading_cycle_shift;
1578     assert(unloading_cycle(state) == value, "unexpected unloading cycle overflow");
1579     return state;
1580   }
1581 
1582 public:
1583   static bool is_unloading(uint8_t state) { return (state & _is_unloading_mask) >> _is_unloading_shift == 1; }
1584   static uint8_t unloading_cycle(uint8_t state) { return (state & _unloading_cycle_mask) >> _unloading_cycle_shift; }
1585 
1586   static uint8_t create(bool is_unloading, uint8_t unloading_cycle) {
1587     uint8_t state = 0;
1588     state = set_is_unloading(state, is_unloading);
1589     state = set_unloading_cycle(state, unloading_cycle);
1590     return state;
1591   }
1592 };
1593 
1594 bool nmethod::is_unloading() {
1595   uint8_t state = RawAccess<MO_RELAXED>::load(&_is_unloading_state);
1596   bool state_is_unloading = IsUnloadingState::is_unloading(state);
1597   uint8_t state_unloading_cycle = IsUnloadingState::unloading_cycle(state);
1598   if (state_is_unloading) {
1599     return true;
1600   }
1601   uint8_t current_cycle = CodeCache::unloading_cycle();
1602   if (state_unloading_cycle == current_cycle) {
1603     return false;
1604   }
1605 
1606   // The IsUnloadingBehaviour is responsible for checking if there are any dead
1607   // oops in the CompiledMethod, by calling oops_do on it.
1608   state_unloading_cycle = current_cycle;
1609 
1610   if (is_zombie()) {
1611     // Zombies without calculated unloading epoch are never unloading due to GC.
1612 
1613     // There are no races where a previously observed is_unloading() nmethod
1614     // suddenly becomes not is_unloading() due to here being observed as zombie.
1615 
1616     // With STW unloading, all is_alive() && is_unloading() nmethods are unlinked
1617     // and unloaded in the safepoint. That makes races where an nmethod is first
1618     // observed as is_alive() && is_unloading() and subsequently observed as
1619     // is_zombie() impossible.
1620 
1621     // With concurrent unloading, all references to is_unloading() nmethods are
1622     // first unlinked (e.g. IC caches and dependency contexts). Then a global
1623     // handshake operation is performed with all JavaThreads before finally
1624     // unloading the nmethods. The sweeper never converts is_alive() && is_unloading()
1625     // nmethods to zombies; it waits for them to become is_unloaded(). So before
1626     // the global handshake, it is impossible for is_unloading() nmethods to
1627     // racingly become is_zombie(). And is_unloading() is calculated for all is_alive()
1628     // nmethods before taking that global handshake, meaning that it will never
1629     // be recalculated after the handshake.
1630 
1631     // After that global handshake, is_unloading() nmethods are only observable
1632     // to the iterators, and they will never trigger recomputation of the cached
1633     // is_unloading_state, and hence may not suffer from such races.
1634 
1635     state_is_unloading = false;
1636   } else {
1637     state_is_unloading = IsUnloadingBehaviour::current()->is_unloading(this);
1638   }
1639 
1640   state = IsUnloadingState::create(state_is_unloading, state_unloading_cycle);
1641 
1642   RawAccess<MO_RELAXED>::store(&_is_unloading_state, state);
1643 
1644   return state_is_unloading;
1645 }
1646 
1647 void nmethod::clear_unloading_state() {
1648   uint8_t state = IsUnloadingState::create(false, CodeCache::unloading_cycle());
1649   RawAccess<MO_RELAXED>::store(&_is_unloading_state, state);
1650 }
1651 
1652 
1653 // This is called at the end of the strong tracing/marking phase of a
1654 // GC to unload an nmethod if it contains otherwise unreachable
1655 // oops.
1656 
1657 void nmethod::do_unloading(bool unloading_occurred) {
1658   // Make sure the oop's ready to receive visitors
1659   assert(!is_zombie() && !is_unloaded(),
1660          "should not call follow on zombie or unloaded nmethod");
1661 
1662   if (is_unloading()) {
1663     make_unloaded();
1664   } else {
1665 #if INCLUDE_JVMCI
1666     if (_jvmci_installed_code != NULL) {
1667       if (JNIHandles::is_global_weak_cleared(_jvmci_installed_code)) {
1668         if (_jvmci_installed_code_triggers_invalidation) {
1669           make_not_entrant();
1670         }
1671         clear_jvmci_installed_code();
1672       }
1673     }
1674 #endif
1675 
1676     guarantee(unload_nmethod_caches(unloading_occurred),
1677               "Should not need transition stubs");
1678   }
1679 }
1680 
1681 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
1682   // make sure the oops ready to receive visitors
1683   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
1684   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
1685 
1686   // Prevent extra code cache walk for platforms that don't have immediate oops.
1687   if (relocInfo::mustIterateImmediateOopsInCode()) {
1688     RelocIterator iter(this, oops_reloc_begin());
1689 
1690     while (iter.next()) {
1691       if (iter.type() == relocInfo::oop_type ) {
1692         oop_Relocation* r = iter.oop_reloc();
1693         // In this loop, we must only follow those oops directly embedded in
1694         // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1695         assert(1 == (r->oop_is_immediate()) +
1696                (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1697                "oop must be found in exactly one place");
1698         if (r->oop_is_immediate() && r->oop_value() != NULL) {
1699           f->do_oop(r->oop_addr());
1700         }
1701       }
1702     }
1703   }
1704 
1705   // Scopes
1706   // This includes oop constants not inlined in the code stream.
1707   for (oop* p = oops_begin(); p < oops_end(); p++) {
1708     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1709     f->do_oop(p);
1710   }
1711 }
1712 
1713 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1714 
1715 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1716 
1717 // An nmethod is "marked" if its _mark_link is set non-null.
1718 // Even if it is the end of the linked list, it will have a non-null link value,
1719 // as long as it is on the list.
1720 // This code must be MP safe, because it is used from parallel GC passes.
1721 bool nmethod::test_set_oops_do_mark() {
1722   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1723   if (_oops_do_mark_link == NULL) {
1724     // Claim this nmethod for this thread to mark.
1725     if (Atomic::replace_if_null(NMETHOD_SENTINEL, &_oops_do_mark_link)) {
1726       // Atomically append this nmethod (now claimed) to the head of the list:
1727       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1728       for (;;) {
1729         nmethod* required_mark_nmethods = observed_mark_nmethods;
1730         _oops_do_mark_link = required_mark_nmethods;
1731         observed_mark_nmethods =
1732           Atomic::cmpxchg(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1733         if (observed_mark_nmethods == required_mark_nmethods)
1734           break;
1735       }
1736       // Mark was clear when we first saw this guy.
1737       LogTarget(Trace, gc, nmethod) lt;
1738       if (lt.is_enabled()) {
1739         LogStream ls(lt);
1740         CompileTask::print(&ls, this, "oops_do, mark", /*short_form:*/ true);
1741       }
1742       return false;
1743     }
1744   }
1745   // On fall through, another racing thread marked this nmethod before we did.
1746   return true;
1747 }
1748 
1749 void nmethod::oops_do_marking_prologue() {
1750   log_trace(gc, nmethod)("oops_do_marking_prologue");
1751   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1752   // We use cmpxchg instead of regular assignment here because the user
1753   // may fork a bunch of threads, and we need them all to see the same state.
1754   nmethod* observed = Atomic::cmpxchg(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, (nmethod*)NULL);
1755   guarantee(observed == NULL, "no races in this sequential code");
1756 }
1757 
1758 void nmethod::oops_do_marking_epilogue() {
1759   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1760   nmethod* cur = _oops_do_mark_nmethods;
1761   while (cur != NMETHOD_SENTINEL) {
1762     assert(cur != NULL, "not NULL-terminated");
1763     nmethod* next = cur->_oops_do_mark_link;
1764     cur->_oops_do_mark_link = NULL;
1765     DEBUG_ONLY(cur->verify_oop_relocations());
1766 
1767     LogTarget(Trace, gc, nmethod) lt;
1768     if (lt.is_enabled()) {
1769       LogStream ls(lt);
1770       CompileTask::print(&ls, cur, "oops_do, unmark", /*short_form:*/ true);
1771     }
1772     cur = next;
1773   }
1774   nmethod* required = _oops_do_mark_nmethods;
1775   nmethod* observed = Atomic::cmpxchg((nmethod*)NULL, &_oops_do_mark_nmethods, required);
1776   guarantee(observed == required, "no races in this sequential code");
1777   log_trace(gc, nmethod)("oops_do_marking_epilogue");
1778 }
1779 
1780 class DetectScavengeRoot: public OopClosure {
1781   bool     _detected_scavenge_root;
1782   nmethod* _print_nm;
1783 public:
1784   DetectScavengeRoot(nmethod* nm) : _detected_scavenge_root(false), _print_nm(nm) {}
1785 
1786   bool detected_scavenge_root() { return _detected_scavenge_root; }
1787   virtual void do_oop(oop* p) {
1788     if ((*p) != NULL && Universe::heap()->is_scavengable(*p)) {
1789       NOT_PRODUCT(maybe_print(p));
1790       _detected_scavenge_root = true;
1791     }
1792   }
1793   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
1794 
1795 #ifndef PRODUCT
1796   void maybe_print(oop* p) {
1797     LogTarget(Trace, gc, nmethod) lt;
1798     if (lt.is_enabled()) {
1799       LogStream ls(lt);
1800       if (!_detected_scavenge_root) {
1801         CompileTask::print(&ls, _print_nm, "new scavenge root", /*short_form:*/ true);
1802       }
1803       ls.print("" PTR_FORMAT "[offset=%d] detected scavengable oop " PTR_FORMAT " (found at " PTR_FORMAT ") ",
1804                p2i(_print_nm), (int)((intptr_t)p - (intptr_t)_print_nm),
1805                p2i(*p), p2i(p));
1806       ls.cr();
1807     }
1808   }
1809 #endif //PRODUCT
1810 };
1811 
1812 bool nmethod::detect_scavenge_root_oops() {
1813   DetectScavengeRoot detect_scavenge_root(this);
1814   oops_do(&detect_scavenge_root);
1815   return detect_scavenge_root.detected_scavenge_root();
1816 }
1817 
1818 inline bool includes(void* p, void* from, void* to) {
1819   return from <= p && p < to;
1820 }
1821 
1822 
1823 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
1824   assert(count >= 2, "must be sentinel values, at least");
1825 
1826 #ifdef ASSERT
1827   // must be sorted and unique; we do a binary search in find_pc_desc()
1828   int prev_offset = pcs[0].pc_offset();
1829   assert(prev_offset == PcDesc::lower_offset_limit,
1830          "must start with a sentinel");
1831   for (int i = 1; i < count; i++) {
1832     int this_offset = pcs[i].pc_offset();
1833     assert(this_offset > prev_offset, "offsets must be sorted");
1834     prev_offset = this_offset;
1835   }
1836   assert(prev_offset == PcDesc::upper_offset_limit,
1837          "must end with a sentinel");
1838 #endif //ASSERT
1839 
1840   // Search for MethodHandle invokes and tag the nmethod.
1841   for (int i = 0; i < count; i++) {
1842     if (pcs[i].is_method_handle_invoke()) {
1843       set_has_method_handle_invokes(true);
1844       break;
1845     }
1846   }
1847   assert(has_method_handle_invokes() == (_deopt_mh_handler_begin != NULL), "must have deopt mh handler");
1848 
1849   int size = count * sizeof(PcDesc);
1850   assert(scopes_pcs_size() >= size, "oob");
1851   memcpy(scopes_pcs_begin(), pcs, size);
1852 
1853   // Adjust the final sentinel downward.
1854   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
1855   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
1856   last_pc->set_pc_offset(content_size() + 1);
1857   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
1858     // Fill any rounding gaps with copies of the last record.
1859     last_pc[1] = last_pc[0];
1860   }
1861   // The following assert could fail if sizeof(PcDesc) is not
1862   // an integral multiple of oopSize (the rounding term).
1863   // If it fails, change the logic to always allocate a multiple
1864   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
1865   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
1866 }
1867 
1868 void nmethod::copy_scopes_data(u_char* buffer, int size) {
1869   assert(scopes_data_size() >= size, "oob");
1870   memcpy(scopes_data_begin(), buffer, size);
1871 }
1872 
1873 #ifdef ASSERT
1874 static PcDesc* linear_search(const PcDescSearch& search, int pc_offset, bool approximate) {
1875   PcDesc* lower = search.scopes_pcs_begin();
1876   PcDesc* upper = search.scopes_pcs_end();
1877   lower += 1; // exclude initial sentinel
1878   PcDesc* res = NULL;
1879   for (PcDesc* p = lower; p < upper; p++) {
1880     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
1881     if (match_desc(p, pc_offset, approximate)) {
1882       if (res == NULL)
1883         res = p;
1884       else
1885         res = (PcDesc*) badAddress;
1886     }
1887   }
1888   return res;
1889 }
1890 #endif
1891 
1892 
1893 // Finds a PcDesc with real-pc equal to "pc"
1894 PcDesc* PcDescContainer::find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search) {
1895   address base_address = search.code_begin();
1896   if ((pc < base_address) ||
1897       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
1898     return NULL;  // PC is wildly out of range
1899   }
1900   int pc_offset = (int) (pc - base_address);
1901 
1902   // Check the PcDesc cache if it contains the desired PcDesc
1903   // (This as an almost 100% hit rate.)
1904   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
1905   if (res != NULL) {
1906     assert(res == linear_search(search, pc_offset, approximate), "cache ok");
1907     return res;
1908   }
1909 
1910   // Fallback algorithm: quasi-linear search for the PcDesc
1911   // Find the last pc_offset less than the given offset.
1912   // The successor must be the required match, if there is a match at all.
1913   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
1914   PcDesc* lower = search.scopes_pcs_begin();
1915   PcDesc* upper = search.scopes_pcs_end();
1916   upper -= 1; // exclude final sentinel
1917   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
1918 
1919 #define assert_LU_OK \
1920   /* invariant on lower..upper during the following search: */ \
1921   assert(lower->pc_offset() <  pc_offset, "sanity"); \
1922   assert(upper->pc_offset() >= pc_offset, "sanity")
1923   assert_LU_OK;
1924 
1925   // Use the last successful return as a split point.
1926   PcDesc* mid = _pc_desc_cache.last_pc_desc();
1927   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1928   if (mid->pc_offset() < pc_offset) {
1929     lower = mid;
1930   } else {
1931     upper = mid;
1932   }
1933 
1934   // Take giant steps at first (4096, then 256, then 16, then 1)
1935   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
1936   const int RADIX = (1 << LOG2_RADIX);
1937   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
1938     while ((mid = lower + step) < upper) {
1939       assert_LU_OK;
1940       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1941       if (mid->pc_offset() < pc_offset) {
1942         lower = mid;
1943       } else {
1944         upper = mid;
1945         break;
1946       }
1947     }
1948     assert_LU_OK;
1949   }
1950 
1951   // Sneak up on the value with a linear search of length ~16.
1952   while (true) {
1953     assert_LU_OK;
1954     mid = lower + 1;
1955     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1956     if (mid->pc_offset() < pc_offset) {
1957       lower = mid;
1958     } else {
1959       upper = mid;
1960       break;
1961     }
1962   }
1963 #undef assert_LU_OK
1964 
1965   if (match_desc(upper, pc_offset, approximate)) {
1966     assert(upper == linear_search(search, pc_offset, approximate), "search ok");
1967     _pc_desc_cache.add_pc_desc(upper);
1968     return upper;
1969   } else {
1970     assert(NULL == linear_search(search, pc_offset, approximate), "search ok");
1971     return NULL;
1972   }
1973 }
1974 
1975 
1976 void nmethod::check_all_dependencies(DepChange& changes) {
1977   // Checked dependencies are allocated into this ResourceMark
1978   ResourceMark rm;
1979 
1980   // Turn off dependency tracing while actually testing dependencies.
1981   NOT_PRODUCT( FlagSetting fs(TraceDependencies, false) );
1982 
1983   typedef ResourceHashtable<DependencySignature, int, &DependencySignature::hash,
1984                             &DependencySignature::equals, 11027> DepTable;
1985 
1986   DepTable* table = new DepTable();
1987 
1988   // Iterate over live nmethods and check dependencies of all nmethods that are not
1989   // marked for deoptimization. A particular dependency is only checked once.
1990   NMethodIterator iter(NMethodIterator::only_alive_and_not_unloading);
1991   while(iter.next()) {
1992     nmethod* nm = iter.method();
1993     // Only notify for live nmethods
1994     if (!nm->is_marked_for_deoptimization()) {
1995       for (Dependencies::DepStream deps(nm); deps.next(); ) {
1996         // Construct abstraction of a dependency.
1997         DependencySignature* current_sig = new DependencySignature(deps);
1998 
1999         // Determine if dependency is already checked. table->put(...) returns
2000         // 'true' if the dependency is added (i.e., was not in the hashtable).
2001         if (table->put(*current_sig, 1)) {
2002           if (deps.check_dependency() != NULL) {
2003             // Dependency checking failed. Print out information about the failed
2004             // dependency and finally fail with an assert. We can fail here, since
2005             // dependency checking is never done in a product build.
2006             tty->print_cr("Failed dependency:");
2007             changes.print();
2008             nm->print();
2009             nm->print_dependencies();
2010             assert(false, "Should have been marked for deoptimization");
2011           }
2012         }
2013       }
2014     }
2015   }
2016 }
2017 
2018 bool nmethod::check_dependency_on(DepChange& changes) {
2019   // What has happened:
2020   // 1) a new class dependee has been added
2021   // 2) dependee and all its super classes have been marked
2022   bool found_check = false;  // set true if we are upset
2023   for (Dependencies::DepStream deps(this); deps.next(); ) {
2024     // Evaluate only relevant dependencies.
2025     if (deps.spot_check_dependency_at(changes) != NULL) {
2026       found_check = true;
2027       NOT_DEBUG(break);
2028     }
2029   }
2030   return found_check;
2031 }
2032 
2033 bool nmethod::is_evol_dependent() {
2034   for (Dependencies::DepStream deps(this); deps.next(); ) {
2035     if (deps.type() == Dependencies::evol_method) {
2036       Method* method = deps.method_argument(0);
2037       if (method->is_old()) {
2038         if (log_is_enabled(Debug, redefine, class, nmethod)) {
2039           ResourceMark rm;
2040           log_debug(redefine, class, nmethod)
2041             ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
2042              _method->method_holder()->external_name(),
2043              _method->name()->as_C_string(),
2044              _method->signature()->as_C_string(),
2045              compile_id(),
2046              method->method_holder()->external_name(),
2047              method->name()->as_C_string(),
2048              method->signature()->as_C_string());
2049         }
2050         if (TraceDependencies || LogCompilation)
2051           deps.log_dependency(method->method_holder());
2052         return true;
2053       }
2054     }
2055   }
2056   return false;
2057 }
2058 
2059 // Called from mark_for_deoptimization, when dependee is invalidated.
2060 bool nmethod::is_dependent_on_method(Method* dependee) {
2061   for (Dependencies::DepStream deps(this); deps.next(); ) {
2062     if (deps.type() != Dependencies::evol_method)
2063       continue;
2064     Method* method = deps.method_argument(0);
2065     if (method == dependee) return true;
2066   }
2067   return false;
2068 }
2069 
2070 
2071 bool nmethod::is_patchable_at(address instr_addr) {
2072   assert(insts_contains(instr_addr), "wrong nmethod used");
2073   if (is_zombie()) {
2074     // a zombie may never be patched
2075     return false;
2076   }
2077   return true;
2078 }
2079 
2080 
2081 address nmethod::continuation_for_implicit_exception(address pc) {
2082   // Exception happened outside inline-cache check code => we are inside
2083   // an active nmethod => use cpc to determine a return address
2084   int exception_offset = pc - code_begin();
2085   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2086 #ifdef ASSERT
2087   if (cont_offset == 0) {
2088     Thread* thread = Thread::current();
2089     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2090     HandleMark hm(thread);
2091     ResourceMark rm(thread);
2092     CodeBlob* cb = CodeCache::find_blob(pc);
2093     assert(cb != NULL && cb == this, "");
2094     ttyLocker ttyl;
2095     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
2096     print();
2097     method()->print_codes();
2098     print_code();
2099     print_pcs();
2100   }
2101 #endif
2102   if (cont_offset == 0) {
2103     // Let the normal error handling report the exception
2104     return NULL;
2105   }
2106   return code_begin() + cont_offset;
2107 }
2108 
2109 
2110 
2111 void nmethod_init() {
2112   // make sure you didn't forget to adjust the filler fields
2113   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2114 }
2115 
2116 
2117 //-------------------------------------------------------------------------------------------
2118 
2119 
2120 // QQQ might we make this work from a frame??
2121 nmethodLocker::nmethodLocker(address pc) {
2122   CodeBlob* cb = CodeCache::find_blob(pc);
2123   guarantee(cb != NULL && cb->is_compiled(), "bad pc for a nmethod found");
2124   _nm = cb->as_compiled_method();
2125   lock_nmethod(_nm);
2126 }
2127 
2128 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2129 // should pass zombie_ok == true.
2130 void nmethodLocker::lock_nmethod(CompiledMethod* cm, bool zombie_ok) {
2131   if (cm == NULL)  return;
2132   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2133   nmethod* nm = cm->as_nmethod();
2134   Atomic::inc(&nm->_lock_count);
2135   assert(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
2136 }
2137 
2138 void nmethodLocker::unlock_nmethod(CompiledMethod* cm) {
2139   if (cm == NULL)  return;
2140   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2141   nmethod* nm = cm->as_nmethod();
2142   Atomic::dec(&nm->_lock_count);
2143   assert(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2144 }
2145 
2146 
2147 // -----------------------------------------------------------------------------
2148 // Verification
2149 
2150 class VerifyOopsClosure: public OopClosure {
2151   nmethod* _nm;
2152   bool     _ok;
2153 public:
2154   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2155   bool ok() { return _ok; }
2156   virtual void do_oop(oop* p) {
2157     if (oopDesc::is_oop_or_null(*p)) return;
2158     if (_ok) {
2159       _nm->print_nmethod(true);
2160       _ok = false;
2161     }
2162     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2163                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2164   }
2165   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2166 };
2167 
2168 void nmethod::verify() {
2169 
2170   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2171   // seems odd.
2172 
2173   if (is_zombie() || is_not_entrant() || is_unloaded())
2174     return;
2175 
2176   // Make sure all the entry points are correctly aligned for patching.
2177   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2178 
2179   // assert(oopDesc::is_oop(method()), "must be valid");
2180 
2181   ResourceMark rm;
2182 
2183   if (!CodeCache::contains(this)) {
2184     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
2185   }
2186 
2187   if(is_native_method() )
2188     return;
2189 
2190   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2191   if (nm != this) {
2192     fatal("findNMethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
2193   }
2194 
2195   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2196     if (! p->verify(this)) {
2197       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
2198     }
2199   }
2200 
2201   VerifyOopsClosure voc(this);
2202   oops_do(&voc);
2203   assert(voc.ok(), "embedded oops must be OK");
2204   Universe::heap()->verify_nmethod(this);
2205 
2206   verify_scopes();
2207 }
2208 
2209 
2210 void nmethod::verify_interrupt_point(address call_site) {
2211   // Verify IC only when nmethod installation is finished.
2212   if (!is_not_installed()) {
2213     if (CompiledICLocker::is_safe(this)) {
2214       CompiledIC_at(this, call_site);
2215       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2216     } else {
2217       CompiledICLocker ml_verify(this);
2218       CompiledIC_at(this, call_site);
2219     }
2220   }
2221 
2222   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
2223   assert(pd != NULL, "PcDesc must exist");
2224   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2225                                      pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
2226                                      pd->return_oop());
2227        !sd->is_top(); sd = sd->sender()) {
2228     sd->verify();
2229   }
2230 }
2231 
2232 void nmethod::verify_scopes() {
2233   if( !method() ) return;       // Runtime stubs have no scope
2234   if (method()->is_native()) return; // Ignore stub methods.
2235   // iterate through all interrupt point
2236   // and verify the debug information is valid.
2237   RelocIterator iter((nmethod*)this);
2238   while (iter.next()) {
2239     address stub = NULL;
2240     switch (iter.type()) {
2241       case relocInfo::virtual_call_type:
2242         verify_interrupt_point(iter.addr());
2243         break;
2244       case relocInfo::opt_virtual_call_type:
2245         stub = iter.opt_virtual_call_reloc()->static_stub(false);
2246         verify_interrupt_point(iter.addr());
2247         break;
2248       case relocInfo::static_call_type:
2249         stub = iter.static_call_reloc()->static_stub(false);
2250         //verify_interrupt_point(iter.addr());
2251         break;
2252       case relocInfo::runtime_call_type:
2253       case relocInfo::runtime_call_w_cp_type: {
2254         address destination = iter.reloc()->value();
2255         // Right now there is no way to find out which entries support
2256         // an interrupt point.  It would be nice if we had this
2257         // information in a table.
2258         break;
2259       }
2260       default:
2261         break;
2262     }
2263     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2264   }
2265 }
2266 
2267 
2268 // -----------------------------------------------------------------------------
2269 // Non-product code
2270 #ifndef PRODUCT
2271 
2272 class DebugScavengeRoot: public OopClosure {
2273   nmethod* _nm;
2274   bool     _ok;
2275 public:
2276   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2277   bool ok() { return _ok; }
2278   virtual void do_oop(oop* p) {
2279     if ((*p) == NULL || !Universe::heap()->is_scavengable(*p))  return;
2280     if (_ok) {
2281       _nm->print_nmethod(true);
2282       _ok = false;
2283     }
2284     tty->print_cr("*** scavengable oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2285                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2286     (*p)->print();
2287   }
2288   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2289 };
2290 
2291 void nmethod::verify_scavenge_root_oops() {
2292   if (!on_scavenge_root_list()) {
2293     // Actually look inside, to verify the claim that it's clean.
2294     DebugScavengeRoot debug_scavenge_root(this);
2295     oops_do(&debug_scavenge_root);
2296     if (!debug_scavenge_root.ok())
2297       fatal("found an unadvertised bad scavengable oop in the code cache");
2298   }
2299   assert(scavenge_root_not_marked(), "");
2300 }
2301 
2302 #endif // PRODUCT
2303 
2304 // Printing operations
2305 
2306 void nmethod::print() const {
2307   ResourceMark rm;
2308   ttyLocker ttyl;   // keep the following output all in one block
2309 
2310   tty->print("Compiled method ");
2311 
2312   if (is_compiled_by_c1()) {
2313     tty->print("(c1) ");
2314   } else if (is_compiled_by_c2()) {
2315     tty->print("(c2) ");
2316   } else if (is_compiled_by_jvmci()) {
2317     tty->print("(JVMCI) ");
2318   } else {
2319     tty->print("(nm) ");
2320   }
2321 
2322   print_on(tty, NULL);
2323 
2324   if (WizardMode) {
2325     tty->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
2326     tty->print(" for method " INTPTR_FORMAT , p2i(method()));
2327     tty->print(" { ");
2328     tty->print_cr("%s ", state());
2329     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2330     tty->print_cr("}:");
2331   }
2332   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2333                                               p2i(this),
2334                                               p2i(this) + size(),
2335                                               size());
2336   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2337                                               p2i(relocation_begin()),
2338                                               p2i(relocation_end()),
2339                                               relocation_size());
2340   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2341                                               p2i(consts_begin()),
2342                                               p2i(consts_end()),
2343                                               consts_size());
2344   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2345                                               p2i(insts_begin()),
2346                                               p2i(insts_end()),
2347                                               insts_size());
2348   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2349                                               p2i(stub_begin()),
2350                                               p2i(stub_end()),
2351                                               stub_size());
2352   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2353                                               p2i(oops_begin()),
2354                                               p2i(oops_end()),
2355                                               oops_size());
2356   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2357                                               p2i(metadata_begin()),
2358                                               p2i(metadata_end()),
2359                                               metadata_size());
2360   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2361                                               p2i(scopes_data_begin()),
2362                                               p2i(scopes_data_end()),
2363                                               scopes_data_size());
2364   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2365                                               p2i(scopes_pcs_begin()),
2366                                               p2i(scopes_pcs_end()),
2367                                               scopes_pcs_size());
2368   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2369                                               p2i(dependencies_begin()),
2370                                               p2i(dependencies_end()),
2371                                               dependencies_size());
2372   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2373                                               p2i(handler_table_begin()),
2374                                               p2i(handler_table_end()),
2375                                               handler_table_size());
2376   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2377                                               p2i(nul_chk_table_begin()),
2378                                               p2i(nul_chk_table_end()),
2379                                               nul_chk_table_size());
2380 }
2381 
2382 #ifndef PRODUCT
2383 
2384 void nmethod::print_scopes() {
2385   // Find the first pc desc for all scopes in the code and print it.
2386   ResourceMark rm;
2387   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2388     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2389       continue;
2390 
2391     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2392     while (sd != NULL) {
2393       sd->print_on(tty, p);
2394       sd = sd->sender();
2395     }
2396   }
2397 }
2398 
2399 void nmethod::print_dependencies() {
2400   ResourceMark rm;
2401   ttyLocker ttyl;   // keep the following output all in one block
2402   tty->print_cr("Dependencies:");
2403   for (Dependencies::DepStream deps(this); deps.next(); ) {
2404     deps.print_dependency();
2405     Klass* ctxk = deps.context_type();
2406     if (ctxk != NULL) {
2407       if (ctxk->is_instance_klass() && InstanceKlass::cast(ctxk)->is_dependent_nmethod(this)) {
2408         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
2409       }
2410     }
2411     deps.log_dependency();  // put it into the xml log also
2412   }
2413 }
2414 
2415 
2416 void nmethod::print_relocations() {
2417   ResourceMark m;       // in case methods get printed via the debugger
2418   tty->print_cr("relocations:");
2419   RelocIterator iter(this);
2420   iter.print();
2421 }
2422 
2423 
2424 void nmethod::print_pcs() {
2425   ResourceMark m;       // in case methods get printed via debugger
2426   tty->print_cr("pc-bytecode offsets:");
2427   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2428     p->print(this);
2429   }
2430 }
2431 
2432 void nmethod::print_recorded_oops() {
2433   tty->print_cr("Recorded oops:");
2434   for (int i = 0; i < oops_count(); i++) {
2435     oop o = oop_at(i);
2436     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(o));
2437     if (o == Universe::non_oop_word()) {
2438       tty->print("non-oop word");
2439     } else {
2440       if (o != NULL) {
2441         o->print_value();
2442       } else {
2443         tty->print_cr("NULL");
2444       }
2445     }
2446     tty->cr();
2447   }
2448 }
2449 
2450 void nmethod::print_recorded_metadata() {
2451   tty->print_cr("Recorded metadata:");
2452   for (int i = 0; i < metadata_count(); i++) {
2453     Metadata* m = metadata_at(i);
2454     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(m));
2455     if (m == (Metadata*)Universe::non_oop_word()) {
2456       tty->print("non-metadata word");
2457     } else {
2458       Metadata::print_value_on_maybe_null(tty, m);
2459     }
2460     tty->cr();
2461   }
2462 }
2463 
2464 #endif // PRODUCT
2465 
2466 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2467   RelocIterator iter(this, begin, end);
2468   bool have_one = false;
2469   while (iter.next()) {
2470     have_one = true;
2471     switch (iter.type()) {
2472         case relocInfo::none:                  return "no_reloc";
2473         case relocInfo::oop_type: {
2474           stringStream st;
2475           oop_Relocation* r = iter.oop_reloc();
2476           oop obj = r->oop_value();
2477           st.print("oop(");
2478           if (obj == NULL) st.print("NULL");
2479           else obj->print_value_on(&st);
2480           st.print(")");
2481           return st.as_string();
2482         }
2483         case relocInfo::metadata_type: {
2484           stringStream st;
2485           metadata_Relocation* r = iter.metadata_reloc();
2486           Metadata* obj = r->metadata_value();
2487           st.print("metadata(");
2488           if (obj == NULL) st.print("NULL");
2489           else obj->print_value_on(&st);
2490           st.print(")");
2491           return st.as_string();
2492         }
2493         case relocInfo::runtime_call_type:
2494         case relocInfo::runtime_call_w_cp_type: {
2495           stringStream st;
2496           st.print("runtime_call");
2497           CallRelocation* r = (CallRelocation*)iter.reloc();
2498           address dest = r->destination();
2499           CodeBlob* cb = CodeCache::find_blob(dest);
2500           if (cb != NULL) {
2501             st.print(" %s", cb->name());
2502           } else {
2503             ResourceMark rm;
2504             const int buflen = 1024;
2505             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
2506             int offset;
2507             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
2508               st.print(" %s", buf);
2509               if (offset != 0) {
2510                 st.print("+%d", offset);
2511               }
2512             }
2513           }
2514           return st.as_string();
2515         }
2516         case relocInfo::virtual_call_type: {
2517           stringStream st;
2518           st.print_raw("virtual_call");
2519           virtual_call_Relocation* r = iter.virtual_call_reloc();
2520           Method* m = r->method_value();
2521           if (m != NULL) {
2522             assert(m->is_method(), "");
2523             m->print_short_name(&st);
2524           }
2525           return st.as_string();
2526         }
2527         case relocInfo::opt_virtual_call_type: {
2528           stringStream st;
2529           st.print_raw("optimized virtual_call");
2530           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
2531           Method* m = r->method_value();
2532           if (m != NULL) {
2533             assert(m->is_method(), "");
2534             m->print_short_name(&st);
2535           }
2536           return st.as_string();
2537         }
2538         case relocInfo::static_call_type: {
2539           stringStream st;
2540           st.print_raw("static_call");
2541           static_call_Relocation* r = iter.static_call_reloc();
2542           Method* m = r->method_value();
2543           if (m != NULL) {
2544             assert(m->is_method(), "");
2545             m->print_short_name(&st);
2546           }
2547           return st.as_string();
2548         }
2549         case relocInfo::static_stub_type:      return "static_stub";
2550         case relocInfo::external_word_type:    return "external_word";
2551         case relocInfo::internal_word_type:    return "internal_word";
2552         case relocInfo::section_word_type:     return "section_word";
2553         case relocInfo::poll_type:             return "poll";
2554         case relocInfo::poll_return_type:      return "poll_return";
2555         case relocInfo::trampoline_stub_type:  return "trampoline_stub";
2556         case relocInfo::type_mask:             return "type_bit_mask";
2557 
2558         default:
2559           break;
2560     }
2561   }
2562   return have_one ? "other" : NULL;
2563 }
2564 
2565 // Return a the last scope in (begin..end]
2566 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2567   PcDesc* p = pc_desc_near(begin+1);
2568   if (p != NULL && p->real_pc(this) <= end) {
2569     return new ScopeDesc(this, p->scope_decode_offset(),
2570                          p->obj_decode_offset(), p->should_reexecute(), p->rethrow_exception(),
2571                          p->return_oop());
2572   }
2573   return NULL;
2574 }
2575 
2576 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
2577   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
2578   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
2579   if (JVMCI_ONLY(_exception_offset >= 0 &&) block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
2580   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
2581   if (JVMCI_ONLY(_deopt_handler_begin != NULL &&) block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
2582 
2583   if (has_method_handle_invokes())
2584     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
2585 
2586   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
2587 
2588   if (block_begin == entry_point()) {
2589     methodHandle m = method();
2590     if (m.not_null()) {
2591       stream->print("  # ");
2592       m->print_value_on(stream);
2593       stream->cr();
2594     }
2595     if (m.not_null() && !is_osr_method()) {
2596       ResourceMark rm;
2597       int sizeargs = m->size_of_parameters();
2598       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2599       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2600       {
2601         int sig_index = 0;
2602         if (!m->is_static())
2603           sig_bt[sig_index++] = T_OBJECT; // 'this'
2604         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2605           BasicType t = ss.type();
2606           sig_bt[sig_index++] = t;
2607           if (type2size[t] == 2) {
2608             sig_bt[sig_index++] = T_VOID;
2609           } else {
2610             assert(type2size[t] == 1, "size is 1 or 2");
2611           }
2612         }
2613         assert(sig_index == sizeargs, "");
2614       }
2615       const char* spname = "sp"; // make arch-specific?
2616       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2617       int stack_slot_offset = this->frame_size() * wordSize;
2618       int tab1 = 14, tab2 = 24;
2619       int sig_index = 0;
2620       int arg_index = (m->is_static() ? 0 : -1);
2621       bool did_old_sp = false;
2622       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2623         bool at_this = (arg_index == -1);
2624         bool at_old_sp = false;
2625         BasicType t = (at_this ? T_OBJECT : ss.type());
2626         assert(t == sig_bt[sig_index], "sigs in sync");
2627         if (at_this)
2628           stream->print("  # this: ");
2629         else
2630           stream->print("  # parm%d: ", arg_index);
2631         stream->move_to(tab1);
2632         VMReg fst = regs[sig_index].first();
2633         VMReg snd = regs[sig_index].second();
2634         if (fst->is_reg()) {
2635           stream->print("%s", fst->name());
2636           if (snd->is_valid())  {
2637             stream->print(":%s", snd->name());
2638           }
2639         } else if (fst->is_stack()) {
2640           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2641           if (offset == stack_slot_offset)  at_old_sp = true;
2642           stream->print("[%s+0x%x]", spname, offset);
2643         } else {
2644           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2645         }
2646         stream->print(" ");
2647         stream->move_to(tab2);
2648         stream->print("= ");
2649         if (at_this) {
2650           m->method_holder()->print_value_on(stream);
2651         } else {
2652           bool did_name = false;
2653           if (!at_this && ss.is_object()) {
2654             Symbol* name = ss.as_symbol_or_null();
2655             if (name != NULL) {
2656               name->print_value_on(stream);
2657               did_name = true;
2658             }
2659           }
2660           if (!did_name)
2661             stream->print("%s", type2name(t));
2662         }
2663         if (at_old_sp) {
2664           stream->print("  (%s of caller)", spname);
2665           did_old_sp = true;
2666         }
2667         stream->cr();
2668         sig_index += type2size[t];
2669         arg_index += 1;
2670         if (!at_this)  ss.next();
2671       }
2672       if (!did_old_sp) {
2673         stream->print("  # ");
2674         stream->move_to(tab1);
2675         stream->print("[%s+0x%x]", spname, stack_slot_offset);
2676         stream->print("  (%s of caller)", spname);
2677         stream->cr();
2678       }
2679     }
2680   }
2681 }
2682 
2683 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
2684   // First, find an oopmap in (begin, end].
2685   // We use the odd half-closed interval so that oop maps and scope descs
2686   // which are tied to the byte after a call are printed with the call itself.
2687   address base = code_begin();
2688   ImmutableOopMapSet* oms = oop_maps();
2689   if (oms != NULL) {
2690     for (int i = 0, imax = oms->count(); i < imax; i++) {
2691       const ImmutableOopMapPair* pair = oms->pair_at(i);
2692       const ImmutableOopMap* om = pair->get_from(oms);
2693       address pc = base + pair->pc_offset();
2694       if (pc > begin) {
2695         if (pc <= end) {
2696           st->move_to(column);
2697           st->print("; ");
2698           om->print_on(st);
2699         }
2700         break;
2701       }
2702     }
2703   }
2704 
2705   // Print any debug info present at this pc.
2706   ScopeDesc* sd  = scope_desc_in(begin, end);
2707   if (sd != NULL) {
2708     st->move_to(column);
2709     if (sd->bci() == SynchronizationEntryBCI) {
2710       st->print(";*synchronization entry");
2711     } else if (sd->bci() == AfterBci) {
2712       st->print(";* method exit (unlocked if synchronized)");
2713     } else if (sd->bci() == UnwindBci) {
2714       st->print(";* unwind (locked if synchronized)");
2715     } else if (sd->bci() == AfterExceptionBci) {
2716       st->print(";* unwind (unlocked if synchronized)");
2717     } else if (sd->bci() == UnknownBci) {
2718       st->print(";* unknown");
2719     } else if (sd->bci() == InvalidFrameStateBci) {
2720       st->print(";* invalid frame state");
2721     } else {
2722       if (sd->method() == NULL) {
2723         st->print("method is NULL");
2724       } else if (sd->method()->is_native()) {
2725         st->print("method is native");
2726       } else {
2727         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
2728         st->print(";*%s", Bytecodes::name(bc));
2729         switch (bc) {
2730         case Bytecodes::_invokevirtual:
2731         case Bytecodes::_invokespecial:
2732         case Bytecodes::_invokestatic:
2733         case Bytecodes::_invokeinterface:
2734           {
2735             Bytecode_invoke invoke(sd->method(), sd->bci());
2736             st->print(" ");
2737             if (invoke.name() != NULL)
2738               invoke.name()->print_symbol_on(st);
2739             else
2740               st->print("<UNKNOWN>");
2741             break;
2742           }
2743         case Bytecodes::_getfield:
2744         case Bytecodes::_putfield:
2745         case Bytecodes::_getstatic:
2746         case Bytecodes::_putstatic:
2747           {
2748             Bytecode_field field(sd->method(), sd->bci());
2749             st->print(" ");
2750             if (field.name() != NULL)
2751               field.name()->print_symbol_on(st);
2752             else
2753               st->print("<UNKNOWN>");
2754           }
2755         default:
2756           break;
2757         }
2758       }
2759       st->print(" {reexecute=%d rethrow=%d return_oop=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop());
2760     }
2761 
2762     // Print all scopes
2763     for (;sd != NULL; sd = sd->sender()) {
2764       st->move_to(column);
2765       st->print("; -");
2766       if (sd->method() == NULL) {
2767         st->print("method is NULL");
2768       } else {
2769         sd->method()->print_short_name(st);
2770       }
2771       int lineno = sd->method()->line_number_from_bci(sd->bci());
2772       if (lineno != -1) {
2773         st->print("@%d (line %d)", sd->bci(), lineno);
2774       } else {
2775         st->print("@%d", sd->bci());
2776       }
2777       st->cr();
2778     }
2779   }
2780 
2781   // Print relocation information
2782   const char* str = reloc_string_for(begin, end);
2783   if (str != NULL) {
2784     if (sd != NULL) st->cr();
2785     st->move_to(column);
2786     st->print(";   {%s}", str);
2787   }
2788   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
2789   if (cont_offset != 0) {
2790     st->move_to(column);
2791     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
2792   }
2793 
2794 }
2795 
2796 class DirectNativeCallWrapper: public NativeCallWrapper {
2797 private:
2798   NativeCall* _call;
2799 
2800 public:
2801   DirectNativeCallWrapper(NativeCall* call) : _call(call) {}
2802 
2803   virtual address destination() const { return _call->destination(); }
2804   virtual address instruction_address() const { return _call->instruction_address(); }
2805   virtual address next_instruction_address() const { return _call->next_instruction_address(); }
2806   virtual address return_address() const { return _call->return_address(); }
2807 
2808   virtual address get_resolve_call_stub(bool is_optimized) const {
2809     if (is_optimized) {
2810       return SharedRuntime::get_resolve_opt_virtual_call_stub();
2811     }
2812     return SharedRuntime::get_resolve_virtual_call_stub();
2813   }
2814 
2815   virtual void set_destination_mt_safe(address dest) {
2816 #if INCLUDE_AOT
2817     if (UseAOT) {
2818       CodeBlob* callee = CodeCache::find_blob(dest);
2819       CompiledMethod* cm = callee->as_compiled_method_or_null();
2820       if (cm != NULL && cm->is_far_code()) {
2821         // Temporary fix, see JDK-8143106
2822         CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2823         csc->set_to_far(methodHandle(cm->method()), dest);
2824         return;
2825       }
2826     }
2827 #endif
2828     _call->set_destination_mt_safe(dest);
2829   }
2830 
2831   virtual void set_to_interpreted(const methodHandle& method, CompiledICInfo& info) {
2832     CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2833 #if INCLUDE_AOT
2834     if (info.to_aot()) {
2835       csc->set_to_far(method, info.entry());
2836     } else
2837 #endif
2838     {
2839       csc->set_to_interpreted(method, info.entry());
2840     }
2841   }
2842 
2843   virtual void verify() const {
2844     // make sure code pattern is actually a call imm32 instruction
2845     _call->verify();
2846     _call->verify_alignment();
2847   }
2848 
2849   virtual void verify_resolve_call(address dest) const {
2850     CodeBlob* db = CodeCache::find_blob_unsafe(dest);
2851     assert(db != NULL && !db->is_adapter_blob(), "must use stub!");
2852   }
2853 
2854   virtual bool is_call_to_interpreted(address dest) const {
2855     CodeBlob* cb = CodeCache::find_blob(_call->instruction_address());
2856     return cb->contains(dest);
2857   }
2858 
2859   virtual bool is_safe_for_patching() const { return false; }
2860 
2861   virtual NativeInstruction* get_load_instruction(virtual_call_Relocation* r) const {
2862     return nativeMovConstReg_at(r->cached_value());
2863   }
2864 
2865   virtual void *get_data(NativeInstruction* instruction) const {
2866     return (void*)((NativeMovConstReg*) instruction)->data();
2867   }
2868 
2869   virtual void set_data(NativeInstruction* instruction, intptr_t data) {
2870     ((NativeMovConstReg*) instruction)->set_data(data);
2871   }
2872 };
2873 
2874 NativeCallWrapper* nmethod::call_wrapper_at(address call) const {
2875   return new DirectNativeCallWrapper((NativeCall*) call);
2876 }
2877 
2878 NativeCallWrapper* nmethod::call_wrapper_before(address return_pc) const {
2879   return new DirectNativeCallWrapper(nativeCall_before(return_pc));
2880 }
2881 
2882 address nmethod::call_instruction_address(address pc) const {
2883   if (NativeCall::is_call_before(pc)) {
2884     NativeCall *ncall = nativeCall_before(pc);
2885     return ncall->instruction_address();
2886   }
2887   return NULL;
2888 }
2889 
2890 CompiledStaticCall* nmethod::compiledStaticCall_at(Relocation* call_site) const {
2891   return CompiledDirectStaticCall::at(call_site);
2892 }
2893 
2894 CompiledStaticCall* nmethod::compiledStaticCall_at(address call_site) const {
2895   return CompiledDirectStaticCall::at(call_site);
2896 }
2897 
2898 CompiledStaticCall* nmethod::compiledStaticCall_before(address return_addr) const {
2899   return CompiledDirectStaticCall::before(return_addr);
2900 }
2901 
2902 #ifndef PRODUCT
2903 
2904 void nmethod::print_value_on(outputStream* st) const {
2905   st->print("nmethod");
2906   print_on(st, NULL);
2907 }
2908 
2909 void nmethod::print_calls(outputStream* st) {
2910   RelocIterator iter(this);
2911   while (iter.next()) {
2912     switch (iter.type()) {
2913     case relocInfo::virtual_call_type:
2914     case relocInfo::opt_virtual_call_type: {
2915       CompiledICLocker ml_verify(this);
2916       CompiledIC_at(&iter)->print();
2917       break;
2918     }
2919     case relocInfo::static_call_type:
2920       st->print_cr("Static call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
2921       CompiledDirectStaticCall::at(iter.reloc())->print();
2922       break;
2923     default:
2924       break;
2925     }
2926   }
2927 }
2928 
2929 void nmethod::print_handler_table() {
2930   ExceptionHandlerTable(this).print();
2931 }
2932 
2933 void nmethod::print_nul_chk_table() {
2934   ImplicitExceptionTable(this).print(code_begin());
2935 }
2936 
2937 void nmethod::print_statistics() {
2938   ttyLocker ttyl;
2939   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
2940   native_nmethod_stats.print_native_nmethod_stats();
2941 #ifdef COMPILER1
2942   c1_java_nmethod_stats.print_nmethod_stats("C1");
2943 #endif
2944 #ifdef COMPILER2
2945   c2_java_nmethod_stats.print_nmethod_stats("C2");
2946 #endif
2947 #if INCLUDE_JVMCI
2948   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
2949 #endif
2950   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
2951   DebugInformationRecorder::print_statistics();
2952 #ifndef PRODUCT
2953   pc_nmethod_stats.print_pc_stats();
2954 #endif
2955   Dependencies::print_statistics();
2956   if (xtty != NULL)  xtty->tail("statistics");
2957 }
2958 
2959 #endif // !PRODUCT
2960 
2961 #if INCLUDE_JVMCI
2962 void nmethod::clear_jvmci_installed_code() {
2963   assert_locked_or_safepoint(Patching_lock);
2964   if (_jvmci_installed_code != NULL) {
2965     JNIHandles::destroy_weak_global(_jvmci_installed_code);
2966     _jvmci_installed_code = NULL;
2967   }
2968 }
2969 
2970 void nmethod::clear_speculation_log() {
2971   assert_locked_or_safepoint(Patching_lock);
2972   if (_speculation_log != NULL) {
2973     JNIHandles::destroy_weak_global(_speculation_log);
2974     _speculation_log = NULL;
2975   }
2976 }
2977 
2978 void nmethod::maybe_invalidate_installed_code() {
2979   if (!is_compiled_by_jvmci()) {
2980     return;
2981   }
2982 
2983   assert(Patching_lock->is_locked() ||
2984          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
2985   oop installed_code = JNIHandles::resolve(_jvmci_installed_code);
2986   if (installed_code != NULL) {
2987     // Update the values in the InstalledCode instance if it still refers to this nmethod
2988     nmethod* nm = (nmethod*)InstalledCode::address(installed_code);
2989     if (nm == this) {
2990       if (!is_alive() || is_unloading()) {
2991         // Break the link between nmethod and InstalledCode such that the nmethod
2992         // can subsequently be flushed safely.  The link must be maintained while
2993         // the method could have live activations since invalidateInstalledCode
2994         // might want to invalidate all existing activations.
2995         InstalledCode::set_address(installed_code, 0);
2996         InstalledCode::set_entryPoint(installed_code, 0);
2997       } else if (is_not_entrant()) {
2998         // Remove the entry point so any invocation will fail but keep
2999         // the address link around that so that existing activations can
3000         // be invalidated.
3001         InstalledCode::set_entryPoint(installed_code, 0);
3002       }
3003     }
3004   }
3005   if (!is_alive() || is_unloading()) {
3006     // Clear these out after the nmethod has been unregistered and any
3007     // updates to the InstalledCode instance have been performed.
3008     clear_jvmci_installed_code();
3009     clear_speculation_log();
3010   }
3011 }
3012 
3013 void nmethod::invalidate_installed_code(Handle installedCode, TRAPS) {
3014   if (installedCode() == NULL) {
3015     THROW(vmSymbols::java_lang_NullPointerException());
3016   }
3017   jlong nativeMethod = InstalledCode::address(installedCode);
3018   nmethod* nm = (nmethod*)nativeMethod;
3019   if (nm == NULL) {
3020     // Nothing to do
3021     return;
3022   }
3023 
3024   nmethodLocker nml(nm);
3025 #ifdef ASSERT
3026   {
3027     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
3028     // This relationship can only be checked safely under a lock
3029     assert(!nm->is_alive() || nm->is_unloading() || nm->jvmci_installed_code() == installedCode(), "sanity check");
3030   }
3031 #endif
3032 
3033   if (nm->is_alive()) {
3034     // Invalidating the InstalledCode means we want the nmethod
3035     // to be deoptimized.
3036     nm->mark_for_deoptimization();
3037     VM_Deoptimize op;
3038     VMThread::execute(&op);
3039   }
3040 
3041   // Multiple threads could reach this point so we now need to
3042   // lock and re-check the link to the nmethod so that only one
3043   // thread clears it.
3044   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
3045   if (InstalledCode::address(installedCode) == nativeMethod) {
3046       InstalledCode::set_address(installedCode, 0);
3047   }
3048 }
3049 
3050 oop nmethod::jvmci_installed_code() {
3051   return JNIHandles::resolve(_jvmci_installed_code);
3052 }
3053 
3054 oop nmethod::speculation_log() {
3055   return JNIHandles::resolve(_speculation_log);
3056 }
3057 
3058 char* nmethod::jvmci_installed_code_name(char* buf, size_t buflen) const {
3059   if (!this->is_compiled_by_jvmci()) {
3060     return NULL;
3061   }
3062   oop installed_code = JNIHandles::resolve(_jvmci_installed_code);
3063   if (installed_code != NULL) {
3064     oop installed_code_name = NULL;
3065     if (installed_code->is_a(InstalledCode::klass())) {
3066       installed_code_name = InstalledCode::name(installed_code);
3067     }
3068     if (installed_code_name != NULL) {
3069       return java_lang_String::as_utf8_string(installed_code_name, buf, (int)buflen);
3070     }
3071   }
3072   return NULL;
3073 }
3074 #endif