1 /*
   2  * Copyright (c) 1997, 2018, 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     if (ScavengeRootsInCode) {
 615       Universe::heap()->register_nmethod(this);
 616     }
 617     debug_only(Universe::heap()->verify_nmethod(this));
 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     if (ScavengeRootsInCode) {
 775       Universe::heap()->register_nmethod(this);
 776     }
 777     debug_only(Universe::heap()->verify_nmethod(this));
 778 
 779     CodeCache::commit(this);
 780 
 781     // Copy contents of ExceptionHandlerTable to nmethod
 782     handler_table->copy_to(this);
 783     nul_chk_table->copy_to(this);
 784 
 785     // we use the information of entry points to find out if a method is
 786     // static or non static
 787     assert(compiler->is_c2() || compiler->is_jvmci() ||
 788            _method->is_static() == (entry_point() == _verified_entry_point),
 789            " entry points must be same for static methods and vice versa");
 790   }
 791 }
 792 
 793 // Print a short set of xml attributes to identify this nmethod.  The
 794 // output should be embedded in some other element.
 795 void nmethod::log_identity(xmlStream* log) const {
 796   log->print(" compile_id='%d'", compile_id());
 797   const char* nm_kind = compile_kind();
 798   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 799   log->print(" compiler='%s'", compiler_name());
 800   if (TieredCompilation) {
 801     log->print(" level='%d'", comp_level());
 802   }
 803 #if INCLUDE_JVMCI
 804     char buffer[O_BUFLEN];
 805     char* jvmci_name = jvmci_installed_code_name(buffer, O_BUFLEN);
 806     if (jvmci_name != NULL) {
 807       log->print(" jvmci_installed_code_name='");
 808       log->text("%s", jvmci_name);
 809       log->print("'");
 810     }
 811 #endif
 812 }
 813 
 814 
 815 #define LOG_OFFSET(log, name)                    \
 816   if (p2i(name##_end()) - p2i(name##_begin())) \
 817     log->print(" " XSTR(name) "_offset='" INTX_FORMAT "'"    , \
 818                p2i(name##_begin()) - p2i(this))
 819 
 820 
 821 void nmethod::log_new_nmethod() const {
 822   if (LogCompilation && xtty != NULL) {
 823     ttyLocker ttyl;
 824     HandleMark hm;
 825     xtty->begin_elem("nmethod");
 826     log_identity(xtty);
 827     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
 828     xtty->print(" address='" INTPTR_FORMAT "'", p2i(this));
 829 
 830     LOG_OFFSET(xtty, relocation);
 831     LOG_OFFSET(xtty, consts);
 832     LOG_OFFSET(xtty, insts);
 833     LOG_OFFSET(xtty, stub);
 834     LOG_OFFSET(xtty, scopes_data);
 835     LOG_OFFSET(xtty, scopes_pcs);
 836     LOG_OFFSET(xtty, dependencies);
 837     LOG_OFFSET(xtty, handler_table);
 838     LOG_OFFSET(xtty, nul_chk_table);
 839     LOG_OFFSET(xtty, oops);
 840     LOG_OFFSET(xtty, metadata);
 841 
 842     xtty->method(method());
 843     xtty->stamp();
 844     xtty->end_elem();
 845   }
 846 }
 847 
 848 #undef LOG_OFFSET
 849 
 850 
 851 // Print out more verbose output usually for a newly created nmethod.
 852 void nmethod::print_on(outputStream* st, const char* msg) const {
 853   if (st != NULL) {
 854     ttyLocker ttyl;
 855     if (WizardMode) {
 856       CompileTask::print(st, this, msg, /*short_form:*/ true);
 857       st->print_cr(" (" INTPTR_FORMAT ")", p2i(this));
 858     } else {
 859       CompileTask::print(st, this, msg, /*short_form:*/ false);
 860     }
 861   }
 862 }
 863 
 864 void nmethod::maybe_print_nmethod(DirectiveSet* directive) {
 865   bool printnmethods = directive->PrintAssemblyOption || directive->PrintNMethodsOption;
 866   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 867     print_nmethod(printnmethods);
 868   }
 869 }
 870 
 871 void nmethod::print_nmethod(bool printmethod) {
 872   ttyLocker ttyl;  // keep the following output all in one block
 873   if (xtty != NULL) {
 874     xtty->begin_head("print_nmethod");
 875     xtty->stamp();
 876     xtty->end_head();
 877   }
 878   // print the header part first
 879   print();
 880   // then print the requested information
 881   if (printmethod) {
 882     print_code();
 883     print_pcs();
 884     if (oop_maps()) {
 885       oop_maps()->print();
 886     }
 887   }
 888   if (printmethod || PrintDebugInfo || CompilerOracle::has_option_string(_method, "PrintDebugInfo")) {
 889     print_scopes();
 890   }
 891   if (printmethod || PrintRelocations || CompilerOracle::has_option_string(_method, "PrintRelocations")) {
 892     print_relocations();
 893   }
 894   if (printmethod || PrintDependencies || CompilerOracle::has_option_string(_method, "PrintDependencies")) {
 895     print_dependencies();
 896   }
 897   if (printmethod || PrintExceptionHandlers) {
 898     print_handler_table();
 899     print_nul_chk_table();
 900   }
 901   if (printmethod) {
 902     print_recorded_oops();
 903     print_recorded_metadata();
 904   }
 905   if (xtty != NULL) {
 906     xtty->tail("print_nmethod");
 907   }
 908 }
 909 
 910 
 911 // Promote one word from an assembly-time handle to a live embedded oop.
 912 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
 913   if (handle == NULL ||
 914       // As a special case, IC oops are initialized to 1 or -1.
 915       handle == (jobject) Universe::non_oop_word()) {
 916     (*dest) = (oop) handle;
 917   } else {
 918     (*dest) = JNIHandles::resolve_non_null(handle);
 919   }
 920 }
 921 
 922 
 923 // Have to have the same name because it's called by a template
 924 void nmethod::copy_values(GrowableArray<jobject>* array) {
 925   int length = array->length();
 926   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
 927   oop* dest = oops_begin();
 928   for (int index = 0 ; index < length; index++) {
 929     initialize_immediate_oop(&dest[index], array->at(index));
 930   }
 931 
 932   // Now we can fix up all the oops in the code.  We need to do this
 933   // in the code because the assembler uses jobjects as placeholders.
 934   // The code and relocations have already been initialized by the
 935   // CodeBlob constructor, so it is valid even at this early point to
 936   // iterate over relocations and patch the code.
 937   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
 938 }
 939 
 940 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
 941   int length = array->length();
 942   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
 943   Metadata** dest = metadata_begin();
 944   for (int index = 0 ; index < length; index++) {
 945     dest[index] = array->at(index);
 946   }
 947 }
 948 
 949 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
 950   // re-patch all oop-bearing instructions, just in case some oops moved
 951   RelocIterator iter(this, begin, end);
 952   while (iter.next()) {
 953     if (iter.type() == relocInfo::oop_type) {
 954       oop_Relocation* reloc = iter.oop_reloc();
 955       if (initialize_immediates && reloc->oop_is_immediate()) {
 956         oop* dest = reloc->oop_addr();
 957         initialize_immediate_oop(dest, (jobject) *dest);
 958       }
 959       // Refresh the oop-related bits of this instruction.
 960       reloc->fix_oop_relocation();
 961     } else if (iter.type() == relocInfo::metadata_type) {
 962       metadata_Relocation* reloc = iter.metadata_reloc();
 963       reloc->fix_metadata_relocation();
 964     }
 965   }
 966 }
 967 
 968 
 969 void nmethod::verify_clean_inline_caches() {
 970   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
 971 
 972   ResourceMark rm;
 973   RelocIterator iter(this, oops_reloc_begin());
 974   while(iter.next()) {
 975     switch(iter.type()) {
 976       case relocInfo::virtual_call_type:
 977       case relocInfo::opt_virtual_call_type: {
 978         CompiledIC *ic = CompiledIC_at(&iter);
 979         // Ok, to lookup references to zombies here
 980         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
 981         assert(cb != NULL, "destination not in CodeBlob?");
 982         nmethod* nm = cb->as_nmethod_or_null();
 983         if( nm != NULL ) {
 984           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 985           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 986             assert(ic->is_clean(), "IC should be clean");
 987           }
 988         }
 989         break;
 990       }
 991       case relocInfo::static_call_type: {
 992         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
 993         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
 994         assert(cb != NULL, "destination not in CodeBlob?");
 995         nmethod* nm = cb->as_nmethod_or_null();
 996         if( nm != NULL ) {
 997           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
 998           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
 999             assert(csc->is_clean(), "IC should be clean");
1000           }
1001         }
1002         break;
1003       }
1004       default:
1005         break;
1006     }
1007   }
1008 }
1009 
1010 // This is a private interface with the sweeper.
1011 void nmethod::mark_as_seen_on_stack() {
1012   assert(is_alive(), "Must be an alive method");
1013   // Set the traversal mark to ensure that the sweeper does 2
1014   // cleaning passes before moving to zombie.
1015   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1016 }
1017 
1018 // Tell if a non-entrant method can be converted to a zombie (i.e.,
1019 // there are no activations on the stack, not in use by the VM,
1020 // and not in use by the ServiceThread)
1021 bool nmethod::can_convert_to_zombie() {
1022   // Note that this is called when the sweeper has observed the nmethod to be
1023   // not_entrant. However, with concurrent code cache unloading, the state
1024   // might have moved on to unloaded if it is_unloading(), due to racing
1025   // concurrent GC threads.
1026   assert(is_not_entrant() || is_unloading(), "must be a non-entrant method");
1027 
1028   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1029   // count can be greater than the stack traversal count before it hits the
1030   // nmethod for the second time.
1031   // If an is_unloading() nmethod is still not_entrant, then it is not safe to
1032   // convert it to zombie due to GC unloading interactions. However, if it
1033   // has become unloaded, then it is okay to convert such nmethods to zombie.
1034   return stack_traversal_mark() + 1 < NMethodSweeper::traversal_count() &&
1035          !is_locked_by_vm() && (!is_unloading() || is_unloaded());
1036 }
1037 
1038 void nmethod::inc_decompile_count() {
1039   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
1040   // Could be gated by ProfileTraps, but do not bother...
1041   Method* m = method();
1042   if (m == NULL)  return;
1043   MethodData* mdo = m->method_data();
1044   if (mdo == NULL)  return;
1045   // There is a benign race here.  See comments in methodData.hpp.
1046   mdo->inc_decompile_count();
1047 }
1048 
1049 void nmethod::make_unloaded() {
1050   post_compiled_method_unload();
1051 
1052   // This nmethod is being unloaded, make sure that dependencies
1053   // recorded in instanceKlasses get flushed.
1054   // Since this work is being done during a GC, defer deleting dependencies from the
1055   // InstanceKlass.
1056   assert(Universe::heap()->is_gc_active() || Thread::current()->is_ConcurrentGC_thread(),
1057          "should only be called during gc");
1058   flush_dependencies(/*delete_immediately*/false);
1059 
1060   // Break cycle between nmethod & method
1061   LogTarget(Trace, class, unload, nmethod) lt;
1062   if (lt.is_enabled()) {
1063     LogStream ls(lt);
1064     ls.print("making nmethod " INTPTR_FORMAT
1065              " unloadable, Method*(" INTPTR_FORMAT
1066              ") ",
1067              p2i(this), p2i(_method));
1068      ls.cr();
1069   }
1070   // Unlink the osr method, so we do not look this up again
1071   if (is_osr_method()) {
1072     // Invalidate the osr nmethod only once
1073     if (is_in_use()) {
1074       invalidate_osr_method();
1075     }
1076 #ifdef ASSERT
1077     if (method() != NULL) {
1078       // Make sure osr nmethod is invalidated, i.e. not on the list
1079       bool found = method()->method_holder()->remove_osr_nmethod(this);
1080       assert(!found, "osr nmethod should have been invalidated");
1081     }
1082 #endif
1083   }
1084 
1085   // If _method is already NULL the Method* is about to be unloaded,
1086   // so we don't have to break the cycle. Note that it is possible to
1087   // have the Method* live here, in case we unload the nmethod because
1088   // it is pointing to some oop (other than the Method*) being unloaded.
1089   if (_method != NULL) {
1090     // OSR methods point to the Method*, but the Method* does not
1091     // point back!
1092     if (_method->code() == this) {
1093       _method->clear_code(); // Break a cycle
1094     }
1095     _method = NULL;            // Clear the method of this dead nmethod
1096   }
1097 
1098   // Make the class unloaded - i.e., change state and notify sweeper
1099   assert(SafepointSynchronize::is_at_safepoint() || Thread::current()->is_ConcurrentGC_thread(),
1100          "must be at safepoint");
1101 
1102   // Unregister must be done before the state change
1103   Universe::heap()->unregister_nmethod(this);
1104 
1105   // Log the unloading.
1106   log_state_change();
1107 
1108 #if INCLUDE_JVMCI
1109   // The method can only be unloaded after the pointer to the installed code
1110   // Java wrapper is no longer alive. Here we need to clear out this weak
1111   // reference to the dead object.
1112   maybe_invalidate_installed_code();
1113 #endif
1114 
1115   // The Method* is gone at this point
1116   assert(_method == NULL, "Tautology");
1117 
1118   set_osr_link(NULL);
1119   NMethodSweeper::report_state_change(this);
1120 
1121   // The release is only needed for compile-time ordering, as accesses
1122   // into the nmethod after the store are not safe due to the sweeper
1123   // being allowed to free it when the store is observed, during
1124   // concurrent nmethod unloading. Therefore, there is no need for
1125   // acquire on the loader side.
1126   OrderAccess::release_store(&_state, (signed char)unloaded);
1127 }
1128 
1129 void nmethod::invalidate_osr_method() {
1130   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1131   // Remove from list of active nmethods
1132   if (method() != NULL) {
1133     method()->method_holder()->remove_osr_nmethod(this);
1134   }
1135 }
1136 
1137 void nmethod::log_state_change() const {
1138   if (LogCompilation) {
1139     if (xtty != NULL) {
1140       ttyLocker ttyl;  // keep the following output all in one block
1141       if (_state == unloaded) {
1142         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1143                          os::current_thread_id());
1144       } else {
1145         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1146                          os::current_thread_id(),
1147                          (_state == zombie ? " zombie='1'" : ""));
1148       }
1149       log_identity(xtty);
1150       xtty->stamp();
1151       xtty->end_elem();
1152     }
1153   }
1154 
1155   const char *state_msg = _state == zombie ? "made zombie" : "made not entrant";
1156   CompileTask::print_ul(this, state_msg);
1157   if (PrintCompilation && _state != unloaded) {
1158     print_on(tty, state_msg);
1159   }
1160 }
1161 
1162 /**
1163  * Common functionality for both make_not_entrant and make_zombie
1164  */
1165 bool nmethod::make_not_entrant_or_zombie(int state) {
1166   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1167   assert(!is_zombie(), "should not already be a zombie");
1168 
1169   if (_state == state) {
1170     // Avoid taking the lock if already in required state.
1171     // This is safe from races because the state is an end-state,
1172     // which the nmethod cannot back out of once entered.
1173     // No need for fencing either.
1174     return false;
1175   }
1176 
1177   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1178   nmethodLocker nml(this);
1179   methodHandle the_method(method());
1180   // This can be called while the system is already at a safepoint which is ok
1181   NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());
1182 
1183   // during patching, depending on the nmethod state we must notify the GC that
1184   // code has been unloaded, unregistering it. We cannot do this right while
1185   // holding the Patching_lock because we need to use the CodeCache_lock. This
1186   // would be prone to deadlocks.
1187   // This flag is used to remember whether we need to later lock and unregister.
1188   bool nmethod_needs_unregister = false;
1189 
1190   {
1191     // invalidate osr nmethod before acquiring the patching lock since
1192     // they both acquire leaf locks and we don't want a deadlock.
1193     // This logic is equivalent to the logic below for patching the
1194     // verified entry point of regular methods. We check that the
1195     // nmethod is in use to ensure that it is invalidated only once.
1196     if (is_osr_method() && is_in_use()) {
1197       // this effectively makes the osr nmethod not entrant
1198       invalidate_osr_method();
1199     }
1200 
1201     // Enter critical section.  Does not block for safepoint.
1202     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1203 
1204     if (_state == state) {
1205       // another thread already performed this transition so nothing
1206       // to do, but return false to indicate this.
1207       return false;
1208     }
1209 
1210     // The caller can be calling the method statically or through an inline
1211     // cache call.
1212     if (!is_osr_method() && !is_not_entrant()) {
1213       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1214                   SharedRuntime::get_handle_wrong_method_stub());
1215     }
1216 
1217     if (is_in_use() && update_recompile_counts()) {
1218       // It's a true state change, so mark the method as decompiled.
1219       // Do it only for transition from alive.
1220       inc_decompile_count();
1221     }
1222 
1223     // If the state is becoming a zombie, signal to unregister the nmethod with
1224     // the heap.
1225     // This nmethod may have already been unloaded during a full GC.
1226     if ((state == zombie) && !is_unloaded()) {
1227       nmethod_needs_unregister = true;
1228     }
1229 
1230     // Must happen before state change. Otherwise we have a race condition in
1231     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
1232     // transition its state from 'not_entrant' to 'zombie' without having to wait
1233     // for stack scanning.
1234     if (state == not_entrant) {
1235       mark_as_seen_on_stack();
1236       OrderAccess::storestore(); // _stack_traversal_mark and _state
1237     }
1238 
1239     // Change state
1240     _state = state;
1241 
1242     // Log the transition once
1243     log_state_change();
1244 
1245     // Invalidate while holding the patching lock
1246     JVMCI_ONLY(maybe_invalidate_installed_code());
1247 
1248     // Remove nmethod from method.
1249     // We need to check if both the _code and _from_compiled_code_entry_point
1250     // refer to this nmethod because there is a race in setting these two fields
1251     // in Method* as seen in bugid 4947125.
1252     // If the vep() points to the zombie nmethod, the memory for the nmethod
1253     // could be flushed and the compiler and vtable stubs could still call
1254     // through it.
1255     if (method() != NULL && (method()->code() == this ||
1256                              method()->from_compiled_entry() == verified_entry_point())) {
1257       HandleMark hm;
1258       method()->clear_code(false /* already owns Patching_lock */);
1259     }
1260   } // leave critical region under Patching_lock
1261 
1262 #ifdef ASSERT
1263   if (is_osr_method() && method() != NULL) {
1264     // Make sure osr nmethod is invalidated, i.e. not on the list
1265     bool found = method()->method_holder()->remove_osr_nmethod(this);
1266     assert(!found, "osr nmethod should have been invalidated");
1267   }
1268 #endif
1269 
1270   // When the nmethod becomes zombie it is no longer alive so the
1271   // dependencies must be flushed.  nmethods in the not_entrant
1272   // state will be flushed later when the transition to zombie
1273   // happens or they get unloaded.
1274   if (state == zombie) {
1275     {
1276       // Flushing dependencies must be done before any possible
1277       // safepoint can sneak in, otherwise the oops used by the
1278       // dependency logic could have become stale.
1279       MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1280       if (nmethod_needs_unregister) {
1281         Universe::heap()->unregister_nmethod(this);
1282       }
1283       flush_dependencies(/*delete_immediately*/true);
1284     }
1285 
1286     // Clear ICStubs to prevent back patching stubs of zombie or flushed
1287     // nmethods during the next safepoint (see ICStub::finalize).
1288     {
1289       CompiledICLocker ml(this);
1290       clear_ic_stubs();
1291     }
1292 
1293     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1294     // event and it hasn't already been reported for this nmethod then
1295     // report it now. The event may have been reported earlier if the GC
1296     // marked it for unloading). JvmtiDeferredEventQueue support means
1297     // we no longer go to a safepoint here.
1298     post_compiled_method_unload();
1299 
1300 #ifdef ASSERT
1301     // It's no longer safe to access the oops section since zombie
1302     // nmethods aren't scanned for GC.
1303     _oops_are_stale = true;
1304 #endif
1305      // the Method may be reclaimed by class unloading now that the
1306      // nmethod is in zombie state
1307     set_method(NULL);
1308   } else {
1309     assert(state == not_entrant, "other cases may need to be handled differently");
1310   }
1311 
1312   if (TraceCreateZombies) {
1313     ResourceMark m;
1314     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");
1315   }
1316 
1317   NMethodSweeper::report_state_change(this);
1318   return true;
1319 }
1320 
1321 void nmethod::flush() {
1322   // Note that there are no valid oops in the nmethod anymore.
1323   assert(!is_osr_method() || is_unloaded() || is_zombie(),
1324          "osr nmethod must be unloaded or zombie before flushing");
1325   assert(is_zombie() || is_osr_method(), "must be a zombie method");
1326   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1327   assert_locked_or_safepoint(CodeCache_lock);
1328 
1329   // completely deallocate this method
1330   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, p2i(this));
1331   if (PrintMethodFlushing) {
1332     tty->print_cr("*flushing %s nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT
1333                   "/Free CodeCache:" SIZE_FORMAT "Kb",
1334                   is_osr_method() ? "osr" : "",_compile_id, p2i(this), CodeCache::blob_count(),
1335                   CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024);
1336   }
1337 
1338   // We need to deallocate any ExceptionCache data.
1339   // Note that we do not need to grab the nmethod lock for this, it
1340   // better be thread safe if we're disposing of it!
1341   ExceptionCache* ec = exception_cache();
1342   set_exception_cache(NULL);
1343   while(ec != NULL) {
1344     ExceptionCache* next = ec->next();
1345     delete ec;
1346     ec = next;
1347   }
1348 
1349   if (on_scavenge_root_list()) {
1350     CodeCache::drop_scavenge_root_nmethod(this);
1351   }
1352 
1353 #if INCLUDE_JVMCI
1354   assert(_jvmci_installed_code == NULL, "should have been nulled out when transitioned to zombie");
1355   assert(_speculation_log == NULL, "should have been nulled out when transitioned to zombie");
1356 #endif
1357 
1358   CodeBlob::flush();
1359   CodeCache::free(this);
1360 }
1361 
1362 oop nmethod::oop_at(int index) const {
1363   if (index == 0) {
1364     return NULL;
1365   }
1366   return NativeAccess<AS_NO_KEEPALIVE>::oop_load(oop_addr_at(index));
1367 }
1368 
1369 //
1370 // Notify all classes this nmethod is dependent on that it is no
1371 // longer dependent. This should only be called in two situations.
1372 // First, when a nmethod transitions to a zombie all dependents need
1373 // to be clear.  Since zombification happens at a safepoint there's no
1374 // synchronization issues.  The second place is a little more tricky.
1375 // During phase 1 of mark sweep class unloading may happen and as a
1376 // result some nmethods may get unloaded.  In this case the flushing
1377 // of dependencies must happen during phase 1 since after GC any
1378 // dependencies in the unloaded nmethod won't be updated, so
1379 // traversing the dependency information in unsafe.  In that case this
1380 // function is called with a boolean argument and this function only
1381 // notifies instanceKlasses that are reachable
1382 
1383 void nmethod::flush_dependencies(bool delete_immediately) {
1384   DEBUG_ONLY(bool called_by_gc = Universe::heap()->is_gc_active() || Thread::current()->is_ConcurrentGC_thread();)
1385   assert(called_by_gc != delete_immediately,
1386   "delete_immediately is false if and only if we are called during GC");
1387   if (!has_flushed_dependencies()) {
1388     set_has_flushed_dependencies();
1389     for (Dependencies::DepStream deps(this); deps.next(); ) {
1390       if (deps.type() == Dependencies::call_site_target_value) {
1391         // CallSite dependencies are managed on per-CallSite instance basis.
1392         oop call_site = deps.argument_oop(0);
1393         if (delete_immediately) {
1394           assert_locked_or_safepoint(CodeCache_lock);
1395           MethodHandles::remove_dependent_nmethod(call_site, this);
1396         } else {
1397           MethodHandles::clean_dependency_context(call_site);
1398         }
1399       } else {
1400         Klass* klass = deps.context_type();
1401         if (klass == NULL) {
1402           continue;  // ignore things like evol_method
1403         }
1404         // During GC delete_immediately is false, and liveness
1405         // of dependee determines class that needs to be updated.
1406         if (delete_immediately) {
1407           assert_locked_or_safepoint(CodeCache_lock);
1408           InstanceKlass::cast(klass)->remove_dependent_nmethod(this);
1409         } else if (klass->is_loader_alive()) {
1410           // The GC may clean dependency contexts concurrently and in parallel.
1411           InstanceKlass::cast(klass)->clean_dependency_context();
1412         }
1413       }
1414     }
1415   }
1416 }
1417 
1418 // ------------------------------------------------------------------
1419 // post_compiled_method_load_event
1420 // new method for install_code() path
1421 // Transfer information from compilation to jvmti
1422 void nmethod::post_compiled_method_load_event() {
1423 
1424   Method* moop = method();
1425   HOTSPOT_COMPILED_METHOD_LOAD(
1426       (char *) moop->klass_name()->bytes(),
1427       moop->klass_name()->utf8_length(),
1428       (char *) moop->name()->bytes(),
1429       moop->name()->utf8_length(),
1430       (char *) moop->signature()->bytes(),
1431       moop->signature()->utf8_length(),
1432       insts_begin(), insts_size());
1433 
1434   if (JvmtiExport::should_post_compiled_method_load() ||
1435       JvmtiExport::should_post_compiled_method_unload()) {
1436     get_and_cache_jmethod_id();
1437   }
1438 
1439   if (JvmtiExport::should_post_compiled_method_load()) {
1440     // Let the Service thread (which is a real Java thread) post the event
1441     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1442     JvmtiDeferredEventQueue::enqueue(
1443       JvmtiDeferredEvent::compiled_method_load_event(this));
1444   }
1445 }
1446 
1447 jmethodID nmethod::get_and_cache_jmethod_id() {
1448   if (_jmethod_id == NULL) {
1449     // Cache the jmethod_id since it can no longer be looked up once the
1450     // method itself has been marked for unloading.
1451     _jmethod_id = method()->jmethod_id();
1452   }
1453   return _jmethod_id;
1454 }
1455 
1456 void nmethod::post_compiled_method_unload() {
1457   if (unload_reported()) {
1458     // During unloading we transition to unloaded and then to zombie
1459     // and the unloading is reported during the first transition.
1460     return;
1461   }
1462 
1463   assert(_method != NULL && !is_unloaded(), "just checking");
1464   DTRACE_METHOD_UNLOAD_PROBE(method());
1465 
1466   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1467   // post the event. Sometime later this nmethod will be made a zombie
1468   // by the sweeper but the Method* will not be valid at that point.
1469   // If the _jmethod_id is null then no load event was ever requested
1470   // so don't bother posting the unload.  The main reason for this is
1471   // that the jmethodID is a weak reference to the Method* so if
1472   // it's being unloaded there's no way to look it up since the weak
1473   // ref will have been cleared.
1474   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1475     assert(!unload_reported(), "already unloaded");
1476     JvmtiDeferredEvent event =
1477       JvmtiDeferredEvent::compiled_method_unload_event(this,
1478           _jmethod_id, insts_begin());
1479     MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
1480     JvmtiDeferredEventQueue::enqueue(event);
1481   }
1482 
1483   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1484   // any time. As the nmethod is being unloaded now we mark it has
1485   // having the unload event reported - this will ensure that we don't
1486   // attempt to report the event in the unlikely scenario where the
1487   // event is enabled at the time the nmethod is made a zombie.
1488   set_unload_reported();
1489 }
1490 
1491 // Iterate over metadata calling this function.   Used by RedefineClasses
1492 void nmethod::metadata_do(void f(Metadata*)) {
1493   {
1494     // Visit all immediate references that are embedded in the instruction stream.
1495     RelocIterator iter(this, oops_reloc_begin());
1496     while (iter.next()) {
1497       if (iter.type() == relocInfo::metadata_type ) {
1498         metadata_Relocation* r = iter.metadata_reloc();
1499         // In this metadata, we must only follow those metadatas directly embedded in
1500         // the code.  Other metadatas (oop_index>0) are seen as part of
1501         // the metadata section below.
1502         assert(1 == (r->metadata_is_immediate()) +
1503                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
1504                "metadata must be found in exactly one place");
1505         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
1506           Metadata* md = r->metadata_value();
1507           if (md != _method) f(md);
1508         }
1509       } else if (iter.type() == relocInfo::virtual_call_type) {
1510         // Check compiledIC holders associated with this nmethod
1511         ResourceMark rm;
1512         CompiledIC *ic = CompiledIC_at(&iter);
1513         if (ic->is_icholder_call()) {
1514           CompiledICHolder* cichk = ic->cached_icholder();
1515           f(cichk->holder_metadata());
1516           f(cichk->holder_klass());
1517         } else {
1518           Metadata* ic_oop = ic->cached_metadata();
1519           if (ic_oop != NULL) {
1520             f(ic_oop);
1521           }
1522         }
1523       }
1524     }
1525   }
1526 
1527   // Visit the metadata section
1528   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
1529     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
1530     Metadata* md = *p;
1531     f(md);
1532   }
1533 
1534   // Visit metadata not embedded in the other places.
1535   if (_method != NULL) f(_method);
1536 }
1537 
1538 // The _is_unloading_state encodes a tuple comprising the unloading cycle
1539 // and the result of IsUnloadingBehaviour::is_unloading() fpr that cycle.
1540 // This is the bit layout of the _is_unloading_state byte: 00000CCU
1541 // CC refers to the cycle, which has 2 bits, and U refers to the result of
1542 // IsUnloadingBehaviour::is_unloading() for that unloading cycle.
1543 
1544 class IsUnloadingState: public AllStatic {
1545   static const uint8_t _is_unloading_mask = 1;
1546   static const uint8_t _is_unloading_shift = 0;
1547   static const uint8_t _unloading_cycle_mask = 6;
1548   static const uint8_t _unloading_cycle_shift = 1;
1549 
1550   static uint8_t set_is_unloading(uint8_t state, bool value) {
1551     state &= ~_is_unloading_mask;
1552     if (value) {
1553       state |= 1 << _is_unloading_shift;
1554     }
1555     assert(is_unloading(state) == value, "unexpected unloading cycle overflow");
1556     return state;
1557   }
1558 
1559   static uint8_t set_unloading_cycle(uint8_t state, uint8_t value) {
1560     state &= ~_unloading_cycle_mask;
1561     state |= value << _unloading_cycle_shift;
1562     assert(unloading_cycle(state) == value, "unexpected unloading cycle overflow");
1563     return state;
1564   }
1565 
1566 public:
1567   static bool is_unloading(uint8_t state) { return (state & _is_unloading_mask) >> _is_unloading_shift == 1; }
1568   static uint8_t unloading_cycle(uint8_t state) { return (state & _unloading_cycle_mask) >> _unloading_cycle_shift; }
1569 
1570   static uint8_t create(bool is_unloading, uint8_t unloading_cycle) {
1571     uint8_t state = 0;
1572     state = set_is_unloading(state, is_unloading);
1573     state = set_unloading_cycle(state, unloading_cycle);
1574     return state;
1575   }
1576 };
1577 
1578 bool nmethod::is_unloading() {
1579   uint8_t state = RawAccess<MO_RELAXED>::load(&_is_unloading_state);
1580   bool state_is_unloading = IsUnloadingState::is_unloading(state);
1581   uint8_t state_unloading_cycle = IsUnloadingState::unloading_cycle(state);
1582   if (state_is_unloading) {
1583     return true;
1584   }
1585   uint8_t current_cycle = CodeCache::unloading_cycle();
1586   if (state_unloading_cycle == current_cycle) {
1587     return false;
1588   }
1589 
1590   // The IsUnloadingBehaviour is responsible for checking if there are any dead
1591   // oops in the CompiledMethod, by calling oops_do on it.
1592   state_unloading_cycle = current_cycle;
1593 
1594   if (is_zombie()) {
1595     // Zombies without calculated unloading epoch are never unloading due to GC.
1596 
1597     // There are no races where a previously observed is_unloading() nmethod
1598     // suddenly becomes not is_unloading() due to here being observed as zombie.
1599 
1600     // With STW unloading, all is_alive() && is_unloading() nmethods are unlinked
1601     // and unloaded in the safepoint. That makes races where an nmethod is first
1602     // observed as is_alive() && is_unloading() and subsequently observed as
1603     // is_zombie() impossible.
1604 
1605     // With concurrent unloading, all references to is_unloading() nmethods are
1606     // first unlinked (e.g. IC caches and dependency contexts). Then a global
1607     // handshake operation is performed with all JavaThreads before finally
1608     // unloading the nmethods. The sweeper never converts is_alive() && is_unloading()
1609     // nmethods to zombies; it waits for them to become is_unloaded(). So before
1610     // the global handshake, it is impossible for is_unloading() nmethods to
1611     // racingly become is_zombie(). And is_unloading() is calculated for all is_alive()
1612     // nmethods before taking that global handshake, meaning that it will never
1613     // be recalculated after the handshake.
1614 
1615     // After that global handshake, is_unloading() nmethods are only observable
1616     // to the iterators, and they will never trigger recomputation of the cached
1617     // is_unloading_state, and hence may not suffer from such races.
1618 
1619     state_is_unloading = false;
1620   } else {
1621     state_is_unloading = IsUnloadingBehaviour::current()->is_unloading(this);
1622   }
1623 
1624   state = IsUnloadingState::create(state_is_unloading, state_unloading_cycle);
1625 
1626   RawAccess<MO_RELAXED>::store(&_is_unloading_state, state);
1627 
1628   return state_is_unloading;
1629 }
1630 
1631 void nmethod::clear_unloading_state() {
1632   uint8_t state = IsUnloadingState::create(false, CodeCache::unloading_cycle());
1633   RawAccess<MO_RELAXED>::store(&_is_unloading_state, state);
1634 }
1635 
1636 
1637 // This is called at the end of the strong tracing/marking phase of a
1638 // GC to unload an nmethod if it contains otherwise unreachable
1639 // oops.
1640 
1641 void nmethod::do_unloading(bool unloading_occurred) {
1642   // Make sure the oop's ready to receive visitors
1643   assert(!is_zombie() && !is_unloaded(),
1644          "should not call follow on zombie or unloaded nmethod");
1645 
1646   if (is_unloading()) {
1647     make_unloaded();
1648   } else {
1649 #if INCLUDE_JVMCI
1650     if (_jvmci_installed_code != NULL) {
1651       if (JNIHandles::is_global_weak_cleared(_jvmci_installed_code)) {
1652         if (_jvmci_installed_code_triggers_invalidation) {
1653           make_not_entrant();
1654         }
1655         clear_jvmci_installed_code();
1656       }
1657     }
1658 #endif
1659 
1660     guarantee(unload_nmethod_caches(unloading_occurred),
1661               "Should not need transition stubs");
1662   }
1663 }
1664 
1665 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
1666   // make sure the oops ready to receive visitors
1667   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
1668   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
1669 
1670   // Prevent extra code cache walk for platforms that don't have immediate oops.
1671   if (relocInfo::mustIterateImmediateOopsInCode()) {
1672     RelocIterator iter(this, oops_reloc_begin());
1673 
1674     while (iter.next()) {
1675       if (iter.type() == relocInfo::oop_type ) {
1676         oop_Relocation* r = iter.oop_reloc();
1677         // In this loop, we must only follow those oops directly embedded in
1678         // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1679         assert(1 == (r->oop_is_immediate()) +
1680                (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1681                "oop must be found in exactly one place");
1682         if (r->oop_is_immediate() && r->oop_value() != NULL) {
1683           f->do_oop(r->oop_addr());
1684         }
1685       }
1686     }
1687   }
1688 
1689   // Scopes
1690   // This includes oop constants not inlined in the code stream.
1691   for (oop* p = oops_begin(); p < oops_end(); p++) {
1692     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1693     f->do_oop(p);
1694   }
1695 }
1696 
1697 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1698 
1699 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1700 
1701 // An nmethod is "marked" if its _mark_link is set non-null.
1702 // Even if it is the end of the linked list, it will have a non-null link value,
1703 // as long as it is on the list.
1704 // This code must be MP safe, because it is used from parallel GC passes.
1705 bool nmethod::test_set_oops_do_mark() {
1706   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1707   if (_oops_do_mark_link == NULL) {
1708     // Claim this nmethod for this thread to mark.
1709     if (Atomic::replace_if_null(NMETHOD_SENTINEL, &_oops_do_mark_link)) {
1710       // Atomically append this nmethod (now claimed) to the head of the list:
1711       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1712       for (;;) {
1713         nmethod* required_mark_nmethods = observed_mark_nmethods;
1714         _oops_do_mark_link = required_mark_nmethods;
1715         observed_mark_nmethods =
1716           Atomic::cmpxchg(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1717         if (observed_mark_nmethods == required_mark_nmethods)
1718           break;
1719       }
1720       // Mark was clear when we first saw this guy.
1721       LogTarget(Trace, gc, nmethod) lt;
1722       if (lt.is_enabled()) {
1723         LogStream ls(lt);
1724         CompileTask::print(&ls, this, "oops_do, mark", /*short_form:*/ true);
1725       }
1726       return false;
1727     }
1728   }
1729   // On fall through, another racing thread marked this nmethod before we did.
1730   return true;
1731 }
1732 
1733 void nmethod::oops_do_marking_prologue() {
1734   log_trace(gc, nmethod)("oops_do_marking_prologue");
1735   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1736   // We use cmpxchg instead of regular assignment here because the user
1737   // may fork a bunch of threads, and we need them all to see the same state.
1738   nmethod* observed = Atomic::cmpxchg(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, (nmethod*)NULL);
1739   guarantee(observed == NULL, "no races in this sequential code");
1740 }
1741 
1742 void nmethod::oops_do_marking_epilogue() {
1743   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1744   nmethod* cur = _oops_do_mark_nmethods;
1745   while (cur != NMETHOD_SENTINEL) {
1746     assert(cur != NULL, "not NULL-terminated");
1747     nmethod* next = cur->_oops_do_mark_link;
1748     cur->_oops_do_mark_link = NULL;
1749     DEBUG_ONLY(cur->verify_oop_relocations());
1750 
1751     LogTarget(Trace, gc, nmethod) lt;
1752     if (lt.is_enabled()) {
1753       LogStream ls(lt);
1754       CompileTask::print(&ls, cur, "oops_do, unmark", /*short_form:*/ true);
1755     }
1756     cur = next;
1757   }
1758   nmethod* required = _oops_do_mark_nmethods;
1759   nmethod* observed = Atomic::cmpxchg((nmethod*)NULL, &_oops_do_mark_nmethods, required);
1760   guarantee(observed == required, "no races in this sequential code");
1761   log_trace(gc, nmethod)("oops_do_marking_epilogue");
1762 }
1763 
1764 class DetectScavengeRoot: public OopClosure {
1765   bool     _detected_scavenge_root;
1766   nmethod* _print_nm;
1767 public:
1768   DetectScavengeRoot(nmethod* nm) : _detected_scavenge_root(false), _print_nm(nm) {}
1769 
1770   bool detected_scavenge_root() { return _detected_scavenge_root; }
1771   virtual void do_oop(oop* p) {
1772     if ((*p) != NULL && Universe::heap()->is_scavengable(*p)) {
1773       NOT_PRODUCT(maybe_print(p));
1774       _detected_scavenge_root = true;
1775     }
1776   }
1777   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
1778 
1779 #ifndef PRODUCT
1780   void maybe_print(oop* p) {
1781     LogTarget(Trace, gc, nmethod) lt;
1782     if (lt.is_enabled()) {
1783       LogStream ls(lt);
1784       if (!_detected_scavenge_root) {
1785         CompileTask::print(&ls, _print_nm, "new scavenge root", /*short_form:*/ true);
1786       }
1787       ls.print("" PTR_FORMAT "[offset=%d] detected scavengable oop " PTR_FORMAT " (found at " PTR_FORMAT ") ",
1788                p2i(_print_nm), (int)((intptr_t)p - (intptr_t)_print_nm),
1789                p2i(*p), p2i(p));
1790       ls.cr();
1791     }
1792   }
1793 #endif //PRODUCT
1794 };
1795 
1796 bool nmethod::detect_scavenge_root_oops() {
1797   DetectScavengeRoot detect_scavenge_root(this);
1798   oops_do(&detect_scavenge_root);
1799   return detect_scavenge_root.detected_scavenge_root();
1800 }
1801 
1802 inline bool includes(void* p, void* from, void* to) {
1803   return from <= p && p < to;
1804 }
1805 
1806 
1807 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
1808   assert(count >= 2, "must be sentinel values, at least");
1809 
1810 #ifdef ASSERT
1811   // must be sorted and unique; we do a binary search in find_pc_desc()
1812   int prev_offset = pcs[0].pc_offset();
1813   assert(prev_offset == PcDesc::lower_offset_limit,
1814          "must start with a sentinel");
1815   for (int i = 1; i < count; i++) {
1816     int this_offset = pcs[i].pc_offset();
1817     assert(this_offset > prev_offset, "offsets must be sorted");
1818     prev_offset = this_offset;
1819   }
1820   assert(prev_offset == PcDesc::upper_offset_limit,
1821          "must end with a sentinel");
1822 #endif //ASSERT
1823 
1824   // Search for MethodHandle invokes and tag the nmethod.
1825   for (int i = 0; i < count; i++) {
1826     if (pcs[i].is_method_handle_invoke()) {
1827       set_has_method_handle_invokes(true);
1828       break;
1829     }
1830   }
1831   assert(has_method_handle_invokes() == (_deopt_mh_handler_begin != NULL), "must have deopt mh handler");
1832 
1833   int size = count * sizeof(PcDesc);
1834   assert(scopes_pcs_size() >= size, "oob");
1835   memcpy(scopes_pcs_begin(), pcs, size);
1836 
1837   // Adjust the final sentinel downward.
1838   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
1839   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
1840   last_pc->set_pc_offset(content_size() + 1);
1841   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
1842     // Fill any rounding gaps with copies of the last record.
1843     last_pc[1] = last_pc[0];
1844   }
1845   // The following assert could fail if sizeof(PcDesc) is not
1846   // an integral multiple of oopSize (the rounding term).
1847   // If it fails, change the logic to always allocate a multiple
1848   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
1849   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
1850 }
1851 
1852 void nmethod::copy_scopes_data(u_char* buffer, int size) {
1853   assert(scopes_data_size() >= size, "oob");
1854   memcpy(scopes_data_begin(), buffer, size);
1855 }
1856 
1857 #ifdef ASSERT
1858 static PcDesc* linear_search(const PcDescSearch& search, int pc_offset, bool approximate) {
1859   PcDesc* lower = search.scopes_pcs_begin();
1860   PcDesc* upper = search.scopes_pcs_end();
1861   lower += 1; // exclude initial sentinel
1862   PcDesc* res = NULL;
1863   for (PcDesc* p = lower; p < upper; p++) {
1864     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
1865     if (match_desc(p, pc_offset, approximate)) {
1866       if (res == NULL)
1867         res = p;
1868       else
1869         res = (PcDesc*) badAddress;
1870     }
1871   }
1872   return res;
1873 }
1874 #endif
1875 
1876 
1877 // Finds a PcDesc with real-pc equal to "pc"
1878 PcDesc* PcDescContainer::find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search) {
1879   address base_address = search.code_begin();
1880   if ((pc < base_address) ||
1881       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
1882     return NULL;  // PC is wildly out of range
1883   }
1884   int pc_offset = (int) (pc - base_address);
1885 
1886   // Check the PcDesc cache if it contains the desired PcDesc
1887   // (This as an almost 100% hit rate.)
1888   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
1889   if (res != NULL) {
1890     assert(res == linear_search(search, pc_offset, approximate), "cache ok");
1891     return res;
1892   }
1893 
1894   // Fallback algorithm: quasi-linear search for the PcDesc
1895   // Find the last pc_offset less than the given offset.
1896   // The successor must be the required match, if there is a match at all.
1897   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
1898   PcDesc* lower = search.scopes_pcs_begin();
1899   PcDesc* upper = search.scopes_pcs_end();
1900   upper -= 1; // exclude final sentinel
1901   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
1902 
1903 #define assert_LU_OK \
1904   /* invariant on lower..upper during the following search: */ \
1905   assert(lower->pc_offset() <  pc_offset, "sanity"); \
1906   assert(upper->pc_offset() >= pc_offset, "sanity")
1907   assert_LU_OK;
1908 
1909   // Use the last successful return as a split point.
1910   PcDesc* mid = _pc_desc_cache.last_pc_desc();
1911   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1912   if (mid->pc_offset() < pc_offset) {
1913     lower = mid;
1914   } else {
1915     upper = mid;
1916   }
1917 
1918   // Take giant steps at first (4096, then 256, then 16, then 1)
1919   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
1920   const int RADIX = (1 << LOG2_RADIX);
1921   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
1922     while ((mid = lower + step) < upper) {
1923       assert_LU_OK;
1924       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1925       if (mid->pc_offset() < pc_offset) {
1926         lower = mid;
1927       } else {
1928         upper = mid;
1929         break;
1930       }
1931     }
1932     assert_LU_OK;
1933   }
1934 
1935   // Sneak up on the value with a linear search of length ~16.
1936   while (true) {
1937     assert_LU_OK;
1938     mid = lower + 1;
1939     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1940     if (mid->pc_offset() < pc_offset) {
1941       lower = mid;
1942     } else {
1943       upper = mid;
1944       break;
1945     }
1946   }
1947 #undef assert_LU_OK
1948 
1949   if (match_desc(upper, pc_offset, approximate)) {
1950     assert(upper == linear_search(search, pc_offset, approximate), "search ok");
1951     _pc_desc_cache.add_pc_desc(upper);
1952     return upper;
1953   } else {
1954     assert(NULL == linear_search(search, pc_offset, approximate), "search ok");
1955     return NULL;
1956   }
1957 }
1958 
1959 
1960 void nmethod::check_all_dependencies(DepChange& changes) {
1961   // Checked dependencies are allocated into this ResourceMark
1962   ResourceMark rm;
1963 
1964   // Turn off dependency tracing while actually testing dependencies.
1965   NOT_PRODUCT( FlagSetting fs(TraceDependencies, false) );
1966 
1967   typedef ResourceHashtable<DependencySignature, int, &DependencySignature::hash,
1968                             &DependencySignature::equals, 11027> DepTable;
1969 
1970   DepTable* table = new DepTable();
1971 
1972   // Iterate over live nmethods and check dependencies of all nmethods that are not
1973   // marked for deoptimization. A particular dependency is only checked once.
1974   NMethodIterator iter(NMethodIterator::only_alive_and_not_unloading);
1975   while(iter.next()) {
1976     nmethod* nm = iter.method();
1977     // Only notify for live nmethods
1978     if (!nm->is_marked_for_deoptimization()) {
1979       for (Dependencies::DepStream deps(nm); deps.next(); ) {
1980         // Construct abstraction of a dependency.
1981         DependencySignature* current_sig = new DependencySignature(deps);
1982 
1983         // Determine if dependency is already checked. table->put(...) returns
1984         // 'true' if the dependency is added (i.e., was not in the hashtable).
1985         if (table->put(*current_sig, 1)) {
1986           if (deps.check_dependency() != NULL) {
1987             // Dependency checking failed. Print out information about the failed
1988             // dependency and finally fail with an assert. We can fail here, since
1989             // dependency checking is never done in a product build.
1990             tty->print_cr("Failed dependency:");
1991             changes.print();
1992             nm->print();
1993             nm->print_dependencies();
1994             assert(false, "Should have been marked for deoptimization");
1995           }
1996         }
1997       }
1998     }
1999   }
2000 }
2001 
2002 bool nmethod::check_dependency_on(DepChange& changes) {
2003   // What has happened:
2004   // 1) a new class dependee has been added
2005   // 2) dependee and all its super classes have been marked
2006   bool found_check = false;  // set true if we are upset
2007   for (Dependencies::DepStream deps(this); deps.next(); ) {
2008     // Evaluate only relevant dependencies.
2009     if (deps.spot_check_dependency_at(changes) != NULL) {
2010       found_check = true;
2011       NOT_DEBUG(break);
2012     }
2013   }
2014   return found_check;
2015 }
2016 
2017 bool nmethod::is_evol_dependent_on(Klass* dependee) {
2018   InstanceKlass *dependee_ik = InstanceKlass::cast(dependee);
2019   Array<Method*>* dependee_methods = dependee_ik->methods();
2020   for (Dependencies::DepStream deps(this); deps.next(); ) {
2021     if (deps.type() == Dependencies::evol_method) {
2022       Method* method = deps.method_argument(0);
2023       for (int j = 0; j < dependee_methods->length(); j++) {
2024         if (dependee_methods->at(j) == method) {
2025           if (log_is_enabled(Debug, redefine, class, nmethod)) {
2026             ResourceMark rm;
2027             log_debug(redefine, class, nmethod)
2028               ("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
2029                _method->method_holder()->external_name(),
2030                _method->name()->as_C_string(),
2031                _method->signature()->as_C_string(),
2032                compile_id(),
2033                method->method_holder()->external_name(),
2034                method->name()->as_C_string(),
2035                method->signature()->as_C_string());
2036           }
2037           if (TraceDependencies || LogCompilation)
2038             deps.log_dependency(dependee);
2039           return true;
2040         }
2041       }
2042     }
2043   }
2044   return false;
2045 }
2046 
2047 // Called from mark_for_deoptimization, when dependee is invalidated.
2048 bool nmethod::is_dependent_on_method(Method* dependee) {
2049   for (Dependencies::DepStream deps(this); deps.next(); ) {
2050     if (deps.type() != Dependencies::evol_method)
2051       continue;
2052     Method* method = deps.method_argument(0);
2053     if (method == dependee) return true;
2054   }
2055   return false;
2056 }
2057 
2058 
2059 bool nmethod::is_patchable_at(address instr_addr) {
2060   assert(insts_contains(instr_addr), "wrong nmethod used");
2061   if (is_zombie()) {
2062     // a zombie may never be patched
2063     return false;
2064   }
2065   return true;
2066 }
2067 
2068 
2069 address nmethod::continuation_for_implicit_exception(address pc) {
2070   // Exception happened outside inline-cache check code => we are inside
2071   // an active nmethod => use cpc to determine a return address
2072   int exception_offset = pc - code_begin();
2073   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2074 #ifdef ASSERT
2075   if (cont_offset == 0) {
2076     Thread* thread = Thread::current();
2077     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2078     HandleMark hm(thread);
2079     ResourceMark rm(thread);
2080     CodeBlob* cb = CodeCache::find_blob(pc);
2081     assert(cb != NULL && cb == this, "");
2082     ttyLocker ttyl;
2083     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
2084     print();
2085     method()->print_codes();
2086     print_code();
2087     print_pcs();
2088   }
2089 #endif
2090   if (cont_offset == 0) {
2091     // Let the normal error handling report the exception
2092     return NULL;
2093   }
2094   return code_begin() + cont_offset;
2095 }
2096 
2097 
2098 
2099 void nmethod_init() {
2100   // make sure you didn't forget to adjust the filler fields
2101   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2102 }
2103 
2104 
2105 //-------------------------------------------------------------------------------------------
2106 
2107 
2108 // QQQ might we make this work from a frame??
2109 nmethodLocker::nmethodLocker(address pc) {
2110   CodeBlob* cb = CodeCache::find_blob(pc);
2111   guarantee(cb != NULL && cb->is_compiled(), "bad pc for a nmethod found");
2112   _nm = cb->as_compiled_method();
2113   lock_nmethod(_nm);
2114 }
2115 
2116 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2117 // should pass zombie_ok == true.
2118 void nmethodLocker::lock_nmethod(CompiledMethod* cm, bool zombie_ok) {
2119   if (cm == NULL)  return;
2120   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2121   nmethod* nm = cm->as_nmethod();
2122   Atomic::inc(&nm->_lock_count);
2123   assert(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
2124 }
2125 
2126 void nmethodLocker::unlock_nmethod(CompiledMethod* cm) {
2127   if (cm == NULL)  return;
2128   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2129   nmethod* nm = cm->as_nmethod();
2130   Atomic::dec(&nm->_lock_count);
2131   assert(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2132 }
2133 
2134 
2135 // -----------------------------------------------------------------------------
2136 // Verification
2137 
2138 class VerifyOopsClosure: public OopClosure {
2139   nmethod* _nm;
2140   bool     _ok;
2141 public:
2142   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2143   bool ok() { return _ok; }
2144   virtual void do_oop(oop* p) {
2145     if (oopDesc::is_oop_or_null(*p)) return;
2146     if (_ok) {
2147       _nm->print_nmethod(true);
2148       _ok = false;
2149     }
2150     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2151                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2152   }
2153   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2154 };
2155 
2156 void nmethod::verify() {
2157 
2158   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2159   // seems odd.
2160 
2161   if (is_zombie() || is_not_entrant() || is_unloaded())
2162     return;
2163 
2164   // Make sure all the entry points are correctly aligned for patching.
2165   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2166 
2167   // assert(oopDesc::is_oop(method()), "must be valid");
2168 
2169   ResourceMark rm;
2170 
2171   if (!CodeCache::contains(this)) {
2172     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
2173   }
2174 
2175   if(is_native_method() )
2176     return;
2177 
2178   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2179   if (nm != this) {
2180     fatal("findNMethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
2181   }
2182 
2183   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2184     if (! p->verify(this)) {
2185       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
2186     }
2187   }
2188 
2189   VerifyOopsClosure voc(this);
2190   oops_do(&voc);
2191   assert(voc.ok(), "embedded oops must be OK");
2192   Universe::heap()->verify_nmethod(this);
2193 
2194   verify_scopes();
2195 }
2196 
2197 
2198 void nmethod::verify_interrupt_point(address call_site) {
2199   // Verify IC only when nmethod installation is finished.
2200   if (!is_not_installed()) {
2201     if (CompiledICLocker::is_safe(this)) {
2202       CompiledIC_at(this, call_site);
2203       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2204     } else {
2205       CompiledICLocker ml_verify(this);
2206       CompiledIC_at(this, call_site);
2207     }
2208   }
2209 
2210   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
2211   assert(pd != NULL, "PcDesc must exist");
2212   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2213                                      pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
2214                                      pd->return_oop());
2215        !sd->is_top(); sd = sd->sender()) {
2216     sd->verify();
2217   }
2218 }
2219 
2220 void nmethod::verify_scopes() {
2221   if( !method() ) return;       // Runtime stubs have no scope
2222   if (method()->is_native()) return; // Ignore stub methods.
2223   // iterate through all interrupt point
2224   // and verify the debug information is valid.
2225   RelocIterator iter((nmethod*)this);
2226   while (iter.next()) {
2227     address stub = NULL;
2228     switch (iter.type()) {
2229       case relocInfo::virtual_call_type:
2230         verify_interrupt_point(iter.addr());
2231         break;
2232       case relocInfo::opt_virtual_call_type:
2233         stub = iter.opt_virtual_call_reloc()->static_stub(false);
2234         verify_interrupt_point(iter.addr());
2235         break;
2236       case relocInfo::static_call_type:
2237         stub = iter.static_call_reloc()->static_stub(false);
2238         //verify_interrupt_point(iter.addr());
2239         break;
2240       case relocInfo::runtime_call_type:
2241       case relocInfo::runtime_call_w_cp_type: {
2242         address destination = iter.reloc()->value();
2243         // Right now there is no way to find out which entries support
2244         // an interrupt point.  It would be nice if we had this
2245         // information in a table.
2246         break;
2247       }
2248       default:
2249         break;
2250     }
2251     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2252   }
2253 }
2254 
2255 
2256 // -----------------------------------------------------------------------------
2257 // Non-product code
2258 #ifndef PRODUCT
2259 
2260 class DebugScavengeRoot: public OopClosure {
2261   nmethod* _nm;
2262   bool     _ok;
2263 public:
2264   DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
2265   bool ok() { return _ok; }
2266   virtual void do_oop(oop* p) {
2267     if ((*p) == NULL || !Universe::heap()->is_scavengable(*p))  return;
2268     if (_ok) {
2269       _nm->print_nmethod(true);
2270       _ok = false;
2271     }
2272     tty->print_cr("*** scavengable oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2273                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2274     (*p)->print();
2275   }
2276   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2277 };
2278 
2279 void nmethod::verify_scavenge_root_oops() {
2280   if (!on_scavenge_root_list()) {
2281     // Actually look inside, to verify the claim that it's clean.
2282     DebugScavengeRoot debug_scavenge_root(this);
2283     oops_do(&debug_scavenge_root);
2284     if (!debug_scavenge_root.ok())
2285       fatal("found an unadvertised bad scavengable oop in the code cache");
2286   }
2287   assert(scavenge_root_not_marked(), "");
2288 }
2289 
2290 #endif // PRODUCT
2291 
2292 // Printing operations
2293 
2294 void nmethod::print() const {
2295   ResourceMark rm;
2296   ttyLocker ttyl;   // keep the following output all in one block
2297 
2298   tty->print("Compiled method ");
2299 
2300   if (is_compiled_by_c1()) {
2301     tty->print("(c1) ");
2302   } else if (is_compiled_by_c2()) {
2303     tty->print("(c2) ");
2304   } else if (is_compiled_by_jvmci()) {
2305     tty->print("(JVMCI) ");
2306   } else {
2307     tty->print("(nm) ");
2308   }
2309 
2310   print_on(tty, NULL);
2311 
2312   if (WizardMode) {
2313     tty->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
2314     tty->print(" for method " INTPTR_FORMAT , p2i(method()));
2315     tty->print(" { ");
2316     tty->print_cr("%s ", state());
2317     if (on_scavenge_root_list())  tty->print("scavenge_root ");
2318     tty->print_cr("}:");
2319   }
2320   if (size              () > 0) tty->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2321                                               p2i(this),
2322                                               p2i(this) + size(),
2323                                               size());
2324   if (relocation_size   () > 0) tty->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2325                                               p2i(relocation_begin()),
2326                                               p2i(relocation_end()),
2327                                               relocation_size());
2328   if (consts_size       () > 0) tty->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2329                                               p2i(consts_begin()),
2330                                               p2i(consts_end()),
2331                                               consts_size());
2332   if (insts_size        () > 0) tty->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2333                                               p2i(insts_begin()),
2334                                               p2i(insts_end()),
2335                                               insts_size());
2336   if (stub_size         () > 0) tty->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2337                                               p2i(stub_begin()),
2338                                               p2i(stub_end()),
2339                                               stub_size());
2340   if (oops_size         () > 0) tty->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2341                                               p2i(oops_begin()),
2342                                               p2i(oops_end()),
2343                                               oops_size());
2344   if (metadata_size      () > 0) tty->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2345                                               p2i(metadata_begin()),
2346                                               p2i(metadata_end()),
2347                                               metadata_size());
2348   if (scopes_data_size  () > 0) tty->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2349                                               p2i(scopes_data_begin()),
2350                                               p2i(scopes_data_end()),
2351                                               scopes_data_size());
2352   if (scopes_pcs_size   () > 0) tty->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2353                                               p2i(scopes_pcs_begin()),
2354                                               p2i(scopes_pcs_end()),
2355                                               scopes_pcs_size());
2356   if (dependencies_size () > 0) tty->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2357                                               p2i(dependencies_begin()),
2358                                               p2i(dependencies_end()),
2359                                               dependencies_size());
2360   if (handler_table_size() > 0) tty->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2361                                               p2i(handler_table_begin()),
2362                                               p2i(handler_table_end()),
2363                                               handler_table_size());
2364   if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2365                                               p2i(nul_chk_table_begin()),
2366                                               p2i(nul_chk_table_end()),
2367                                               nul_chk_table_size());
2368 }
2369 
2370 #ifndef PRODUCT
2371 
2372 void nmethod::print_scopes() {
2373   // Find the first pc desc for all scopes in the code and print it.
2374   ResourceMark rm;
2375   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2376     if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2377       continue;
2378 
2379     ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2380     while (sd != NULL) {
2381       sd->print_on(tty, p);
2382       sd = sd->sender();
2383     }
2384   }
2385 }
2386 
2387 void nmethod::print_dependencies() {
2388   ResourceMark rm;
2389   ttyLocker ttyl;   // keep the following output all in one block
2390   tty->print_cr("Dependencies:");
2391   for (Dependencies::DepStream deps(this); deps.next(); ) {
2392     deps.print_dependency();
2393     Klass* ctxk = deps.context_type();
2394     if (ctxk != NULL) {
2395       if (ctxk->is_instance_klass() && InstanceKlass::cast(ctxk)->is_dependent_nmethod(this)) {
2396         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
2397       }
2398     }
2399     deps.log_dependency();  // put it into the xml log also
2400   }
2401 }
2402 
2403 
2404 void nmethod::print_relocations() {
2405   ResourceMark m;       // in case methods get printed via the debugger
2406   tty->print_cr("relocations:");
2407   RelocIterator iter(this);
2408   iter.print();
2409 }
2410 
2411 
2412 void nmethod::print_pcs() {
2413   ResourceMark m;       // in case methods get printed via debugger
2414   tty->print_cr("pc-bytecode offsets:");
2415   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2416     p->print(this);
2417   }
2418 }
2419 
2420 void nmethod::print_recorded_oops() {
2421   tty->print_cr("Recorded oops:");
2422   for (int i = 0; i < oops_count(); i++) {
2423     oop o = oop_at(i);
2424     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(o));
2425     if (o == Universe::non_oop_word()) {
2426       tty->print("non-oop word");
2427     } else {
2428       if (o != NULL) {
2429         o->print_value();
2430       } else {
2431         tty->print_cr("NULL");
2432       }
2433     }
2434     tty->cr();
2435   }
2436 }
2437 
2438 void nmethod::print_recorded_metadata() {
2439   tty->print_cr("Recorded metadata:");
2440   for (int i = 0; i < metadata_count(); i++) {
2441     Metadata* m = metadata_at(i);
2442     tty->print("#%3d: " INTPTR_FORMAT " ", i, p2i(m));
2443     if (m == (Metadata*)Universe::non_oop_word()) {
2444       tty->print("non-metadata word");
2445     } else {
2446       Metadata::print_value_on_maybe_null(tty, m);
2447     }
2448     tty->cr();
2449   }
2450 }
2451 
2452 #endif // PRODUCT
2453 
2454 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2455   RelocIterator iter(this, begin, end);
2456   bool have_one = false;
2457   while (iter.next()) {
2458     have_one = true;
2459     switch (iter.type()) {
2460         case relocInfo::none:                  return "no_reloc";
2461         case relocInfo::oop_type: {
2462           stringStream st;
2463           oop_Relocation* r = iter.oop_reloc();
2464           oop obj = r->oop_value();
2465           st.print("oop(");
2466           if (obj == NULL) st.print("NULL");
2467           else obj->print_value_on(&st);
2468           st.print(")");
2469           return st.as_string();
2470         }
2471         case relocInfo::metadata_type: {
2472           stringStream st;
2473           metadata_Relocation* r = iter.metadata_reloc();
2474           Metadata* obj = r->metadata_value();
2475           st.print("metadata(");
2476           if (obj == NULL) st.print("NULL");
2477           else obj->print_value_on(&st);
2478           st.print(")");
2479           return st.as_string();
2480         }
2481         case relocInfo::runtime_call_type:
2482         case relocInfo::runtime_call_w_cp_type: {
2483           stringStream st;
2484           st.print("runtime_call");
2485           CallRelocation* r = (CallRelocation*)iter.reloc();
2486           address dest = r->destination();
2487           CodeBlob* cb = CodeCache::find_blob(dest);
2488           if (cb != NULL) {
2489             st.print(" %s", cb->name());
2490           } else {
2491             ResourceMark rm;
2492             const int buflen = 1024;
2493             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
2494             int offset;
2495             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
2496               st.print(" %s", buf);
2497               if (offset != 0) {
2498                 st.print("+%d", offset);
2499               }
2500             }
2501           }
2502           return st.as_string();
2503         }
2504         case relocInfo::virtual_call_type: {
2505           stringStream st;
2506           st.print_raw("virtual_call");
2507           virtual_call_Relocation* r = iter.virtual_call_reloc();
2508           Method* m = r->method_value();
2509           if (m != NULL) {
2510             assert(m->is_method(), "");
2511             m->print_short_name(&st);
2512           }
2513           return st.as_string();
2514         }
2515         case relocInfo::opt_virtual_call_type: {
2516           stringStream st;
2517           st.print_raw("optimized virtual_call");
2518           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
2519           Method* m = r->method_value();
2520           if (m != NULL) {
2521             assert(m->is_method(), "");
2522             m->print_short_name(&st);
2523           }
2524           return st.as_string();
2525         }
2526         case relocInfo::static_call_type: {
2527           stringStream st;
2528           st.print_raw("static_call");
2529           static_call_Relocation* r = iter.static_call_reloc();
2530           Method* m = r->method_value();
2531           if (m != NULL) {
2532             assert(m->is_method(), "");
2533             m->print_short_name(&st);
2534           }
2535           return st.as_string();
2536         }
2537         case relocInfo::static_stub_type:      return "static_stub";
2538         case relocInfo::external_word_type:    return "external_word";
2539         case relocInfo::internal_word_type:    return "internal_word";
2540         case relocInfo::section_word_type:     return "section_word";
2541         case relocInfo::poll_type:             return "poll";
2542         case relocInfo::poll_return_type:      return "poll_return";
2543         case relocInfo::type_mask:             return "type_bit_mask";
2544 
2545         default:
2546           break;
2547     }
2548   }
2549   return have_one ? "other" : NULL;
2550 }
2551 
2552 // Return a the last scope in (begin..end]
2553 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2554   PcDesc* p = pc_desc_near(begin+1);
2555   if (p != NULL && p->real_pc(this) <= end) {
2556     return new ScopeDesc(this, p->scope_decode_offset(),
2557                          p->obj_decode_offset(), p->should_reexecute(), p->rethrow_exception(),
2558                          p->return_oop());
2559   }
2560   return NULL;
2561 }
2562 
2563 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
2564   if (block_begin == entry_point())             stream->print_cr("[Entry Point]");
2565   if (block_begin == verified_entry_point())    stream->print_cr("[Verified Entry Point]");
2566   if (JVMCI_ONLY(_exception_offset >= 0 &&) block_begin == exception_begin())         stream->print_cr("[Exception Handler]");
2567   if (block_begin == stub_begin())              stream->print_cr("[Stub Code]");
2568   if (JVMCI_ONLY(_deopt_handler_begin != NULL &&) block_begin == deopt_handler_begin())     stream->print_cr("[Deopt Handler Code]");
2569 
2570   if (has_method_handle_invokes())
2571     if (block_begin == deopt_mh_handler_begin())  stream->print_cr("[Deopt MH Handler Code]");
2572 
2573   if (block_begin == consts_begin())            stream->print_cr("[Constants]");
2574 
2575   if (block_begin == entry_point()) {
2576     methodHandle m = method();
2577     if (m.not_null()) {
2578       stream->print("  # ");
2579       m->print_value_on(stream);
2580       stream->cr();
2581     }
2582     if (m.not_null() && !is_osr_method()) {
2583       ResourceMark rm;
2584       int sizeargs = m->size_of_parameters();
2585       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2586       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2587       {
2588         int sig_index = 0;
2589         if (!m->is_static())
2590           sig_bt[sig_index++] = T_OBJECT; // 'this'
2591         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2592           BasicType t = ss.type();
2593           sig_bt[sig_index++] = t;
2594           if (type2size[t] == 2) {
2595             sig_bt[sig_index++] = T_VOID;
2596           } else {
2597             assert(type2size[t] == 1, "size is 1 or 2");
2598           }
2599         }
2600         assert(sig_index == sizeargs, "");
2601       }
2602       const char* spname = "sp"; // make arch-specific?
2603       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2604       int stack_slot_offset = this->frame_size() * wordSize;
2605       int tab1 = 14, tab2 = 24;
2606       int sig_index = 0;
2607       int arg_index = (m->is_static() ? 0 : -1);
2608       bool did_old_sp = false;
2609       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2610         bool at_this = (arg_index == -1);
2611         bool at_old_sp = false;
2612         BasicType t = (at_this ? T_OBJECT : ss.type());
2613         assert(t == sig_bt[sig_index], "sigs in sync");
2614         if (at_this)
2615           stream->print("  # this: ");
2616         else
2617           stream->print("  # parm%d: ", arg_index);
2618         stream->move_to(tab1);
2619         VMReg fst = regs[sig_index].first();
2620         VMReg snd = regs[sig_index].second();
2621         if (fst->is_reg()) {
2622           stream->print("%s", fst->name());
2623           if (snd->is_valid())  {
2624             stream->print(":%s", snd->name());
2625           }
2626         } else if (fst->is_stack()) {
2627           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2628           if (offset == stack_slot_offset)  at_old_sp = true;
2629           stream->print("[%s+0x%x]", spname, offset);
2630         } else {
2631           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2632         }
2633         stream->print(" ");
2634         stream->move_to(tab2);
2635         stream->print("= ");
2636         if (at_this) {
2637           m->method_holder()->print_value_on(stream);
2638         } else {
2639           bool did_name = false;
2640           if (!at_this && ss.is_object()) {
2641             Symbol* name = ss.as_symbol_or_null();
2642             if (name != NULL) {
2643               name->print_value_on(stream);
2644               did_name = true;
2645             }
2646           }
2647           if (!did_name)
2648             stream->print("%s", type2name(t));
2649         }
2650         if (at_old_sp) {
2651           stream->print("  (%s of caller)", spname);
2652           did_old_sp = true;
2653         }
2654         stream->cr();
2655         sig_index += type2size[t];
2656         arg_index += 1;
2657         if (!at_this)  ss.next();
2658       }
2659       if (!did_old_sp) {
2660         stream->print("  # ");
2661         stream->move_to(tab1);
2662         stream->print("[%s+0x%x]", spname, stack_slot_offset);
2663         stream->print("  (%s of caller)", spname);
2664         stream->cr();
2665       }
2666     }
2667   }
2668 }
2669 
2670 void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
2671   // First, find an oopmap in (begin, end].
2672   // We use the odd half-closed interval so that oop maps and scope descs
2673   // which are tied to the byte after a call are printed with the call itself.
2674   address base = code_begin();
2675   ImmutableOopMapSet* oms = oop_maps();
2676   if (oms != NULL) {
2677     for (int i = 0, imax = oms->count(); i < imax; i++) {
2678       const ImmutableOopMapPair* pair = oms->pair_at(i);
2679       const ImmutableOopMap* om = pair->get_from(oms);
2680       address pc = base + pair->pc_offset();
2681       if (pc > begin) {
2682         if (pc <= end) {
2683           st->move_to(column);
2684           st->print("; ");
2685           om->print_on(st);
2686         }
2687         break;
2688       }
2689     }
2690   }
2691 
2692   // Print any debug info present at this pc.
2693   ScopeDesc* sd  = scope_desc_in(begin, end);
2694   if (sd != NULL) {
2695     st->move_to(column);
2696     if (sd->bci() == SynchronizationEntryBCI) {
2697       st->print(";*synchronization entry");
2698     } else if (sd->bci() == AfterBci) {
2699       st->print(";* method exit (unlocked if synchronized)");
2700     } else if (sd->bci() == UnwindBci) {
2701       st->print(";* unwind (locked if synchronized)");
2702     } else if (sd->bci() == AfterExceptionBci) {
2703       st->print(";* unwind (unlocked if synchronized)");
2704     } else if (sd->bci() == UnknownBci) {
2705       st->print(";* unknown");
2706     } else if (sd->bci() == InvalidFrameStateBci) {
2707       st->print(";* invalid frame state");
2708     } else {
2709       if (sd->method() == NULL) {
2710         st->print("method is NULL");
2711       } else if (sd->method()->is_native()) {
2712         st->print("method is native");
2713       } else {
2714         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
2715         st->print(";*%s", Bytecodes::name(bc));
2716         switch (bc) {
2717         case Bytecodes::_invokevirtual:
2718         case Bytecodes::_invokespecial:
2719         case Bytecodes::_invokestatic:
2720         case Bytecodes::_invokeinterface:
2721           {
2722             Bytecode_invoke invoke(sd->method(), sd->bci());
2723             st->print(" ");
2724             if (invoke.name() != NULL)
2725               invoke.name()->print_symbol_on(st);
2726             else
2727               st->print("<UNKNOWN>");
2728             break;
2729           }
2730         case Bytecodes::_getfield:
2731         case Bytecodes::_putfield:
2732         case Bytecodes::_getstatic:
2733         case Bytecodes::_putstatic:
2734           {
2735             Bytecode_field field(sd->method(), sd->bci());
2736             st->print(" ");
2737             if (field.name() != NULL)
2738               field.name()->print_symbol_on(st);
2739             else
2740               st->print("<UNKNOWN>");
2741           }
2742         default:
2743           break;
2744         }
2745       }
2746       st->print(" {reexecute=%d rethrow=%d return_oop=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop());
2747     }
2748 
2749     // Print all scopes
2750     for (;sd != NULL; sd = sd->sender()) {
2751       st->move_to(column);
2752       st->print("; -");
2753       if (sd->method() == NULL) {
2754         st->print("method is NULL");
2755       } else {
2756         sd->method()->print_short_name(st);
2757       }
2758       int lineno = sd->method()->line_number_from_bci(sd->bci());
2759       if (lineno != -1) {
2760         st->print("@%d (line %d)", sd->bci(), lineno);
2761       } else {
2762         st->print("@%d", sd->bci());
2763       }
2764       st->cr();
2765     }
2766   }
2767 
2768   // Print relocation information
2769   const char* str = reloc_string_for(begin, end);
2770   if (str != NULL) {
2771     if (sd != NULL) st->cr();
2772     st->move_to(column);
2773     st->print(";   {%s}", str);
2774   }
2775   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
2776   if (cont_offset != 0) {
2777     st->move_to(column);
2778     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
2779   }
2780 
2781 }
2782 
2783 class DirectNativeCallWrapper: public NativeCallWrapper {
2784 private:
2785   NativeCall* _call;
2786 
2787 public:
2788   DirectNativeCallWrapper(NativeCall* call) : _call(call) {}
2789 
2790   virtual address destination() const { return _call->destination(); }
2791   virtual address instruction_address() const { return _call->instruction_address(); }
2792   virtual address next_instruction_address() const { return _call->next_instruction_address(); }
2793   virtual address return_address() const { return _call->return_address(); }
2794 
2795   virtual address get_resolve_call_stub(bool is_optimized) const {
2796     if (is_optimized) {
2797       return SharedRuntime::get_resolve_opt_virtual_call_stub();
2798     }
2799     return SharedRuntime::get_resolve_virtual_call_stub();
2800   }
2801 
2802   virtual void set_destination_mt_safe(address dest) {
2803 #if INCLUDE_AOT
2804     if (UseAOT) {
2805       CodeBlob* callee = CodeCache::find_blob(dest);
2806       CompiledMethod* cm = callee->as_compiled_method_or_null();
2807       if (cm != NULL && cm->is_far_code()) {
2808         // Temporary fix, see JDK-8143106
2809         CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2810         csc->set_to_far(methodHandle(cm->method()), dest);
2811         return;
2812       }
2813     }
2814 #endif
2815     _call->set_destination_mt_safe(dest);
2816   }
2817 
2818   virtual void set_to_interpreted(const methodHandle& method, CompiledICInfo& info) {
2819     CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
2820 #if INCLUDE_AOT
2821     if (info.to_aot()) {
2822       csc->set_to_far(method, info.entry());
2823     } else
2824 #endif
2825     {
2826       csc->set_to_interpreted(method, info.entry());
2827     }
2828   }
2829 
2830   virtual void verify() const {
2831     // make sure code pattern is actually a call imm32 instruction
2832     _call->verify();
2833     _call->verify_alignment();
2834   }
2835 
2836   virtual void verify_resolve_call(address dest) const {
2837     CodeBlob* db = CodeCache::find_blob_unsafe(dest);
2838     assert(db != NULL && !db->is_adapter_blob(), "must use stub!");
2839   }
2840 
2841   virtual bool is_call_to_interpreted(address dest) const {
2842     CodeBlob* cb = CodeCache::find_blob(_call->instruction_address());
2843     return cb->contains(dest);
2844   }
2845 
2846   virtual bool is_safe_for_patching() const { return false; }
2847 
2848   virtual NativeInstruction* get_load_instruction(virtual_call_Relocation* r) const {
2849     return nativeMovConstReg_at(r->cached_value());
2850   }
2851 
2852   virtual void *get_data(NativeInstruction* instruction) const {
2853     return (void*)((NativeMovConstReg*) instruction)->data();
2854   }
2855 
2856   virtual void set_data(NativeInstruction* instruction, intptr_t data) {
2857     ((NativeMovConstReg*) instruction)->set_data(data);
2858   }
2859 };
2860 
2861 NativeCallWrapper* nmethod::call_wrapper_at(address call) const {
2862   return new DirectNativeCallWrapper((NativeCall*) call);
2863 }
2864 
2865 NativeCallWrapper* nmethod::call_wrapper_before(address return_pc) const {
2866   return new DirectNativeCallWrapper(nativeCall_before(return_pc));
2867 }
2868 
2869 address nmethod::call_instruction_address(address pc) const {
2870   if (NativeCall::is_call_before(pc)) {
2871     NativeCall *ncall = nativeCall_before(pc);
2872     return ncall->instruction_address();
2873   }
2874   return NULL;
2875 }
2876 
2877 CompiledStaticCall* nmethod::compiledStaticCall_at(Relocation* call_site) const {
2878   return CompiledDirectStaticCall::at(call_site);
2879 }
2880 
2881 CompiledStaticCall* nmethod::compiledStaticCall_at(address call_site) const {
2882   return CompiledDirectStaticCall::at(call_site);
2883 }
2884 
2885 CompiledStaticCall* nmethod::compiledStaticCall_before(address return_addr) const {
2886   return CompiledDirectStaticCall::before(return_addr);
2887 }
2888 
2889 #ifndef PRODUCT
2890 
2891 void nmethod::print_value_on(outputStream* st) const {
2892   st->print("nmethod");
2893   print_on(st, NULL);
2894 }
2895 
2896 void nmethod::print_calls(outputStream* st) {
2897   RelocIterator iter(this);
2898   while (iter.next()) {
2899     switch (iter.type()) {
2900     case relocInfo::virtual_call_type:
2901     case relocInfo::opt_virtual_call_type: {
2902       CompiledICLocker ml_verify(this);
2903       CompiledIC_at(&iter)->print();
2904       break;
2905     }
2906     case relocInfo::static_call_type:
2907       st->print_cr("Static call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
2908       CompiledDirectStaticCall::at(iter.reloc())->print();
2909       break;
2910     default:
2911       break;
2912     }
2913   }
2914 }
2915 
2916 void nmethod::print_handler_table() {
2917   ExceptionHandlerTable(this).print();
2918 }
2919 
2920 void nmethod::print_nul_chk_table() {
2921   ImplicitExceptionTable(this).print(code_begin());
2922 }
2923 
2924 void nmethod::print_statistics() {
2925   ttyLocker ttyl;
2926   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
2927   native_nmethod_stats.print_native_nmethod_stats();
2928 #ifdef COMPILER1
2929   c1_java_nmethod_stats.print_nmethod_stats("C1");
2930 #endif
2931 #ifdef COMPILER2
2932   c2_java_nmethod_stats.print_nmethod_stats("C2");
2933 #endif
2934 #if INCLUDE_JVMCI
2935   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
2936 #endif
2937   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
2938   DebugInformationRecorder::print_statistics();
2939 #ifndef PRODUCT
2940   pc_nmethod_stats.print_pc_stats();
2941 #endif
2942   Dependencies::print_statistics();
2943   if (xtty != NULL)  xtty->tail("statistics");
2944 }
2945 
2946 #endif // !PRODUCT
2947 
2948 #if INCLUDE_JVMCI
2949 void nmethod::clear_jvmci_installed_code() {
2950   assert_locked_or_safepoint(Patching_lock);
2951   if (_jvmci_installed_code != NULL) {
2952     JNIHandles::destroy_weak_global(_jvmci_installed_code);
2953     _jvmci_installed_code = NULL;
2954   }
2955 }
2956 
2957 void nmethod::clear_speculation_log() {
2958   assert_locked_or_safepoint(Patching_lock);
2959   if (_speculation_log != NULL) {
2960     JNIHandles::destroy_weak_global(_speculation_log);
2961     _speculation_log = NULL;
2962   }
2963 }
2964 
2965 void nmethod::maybe_invalidate_installed_code() {
2966   if (!is_compiled_by_jvmci()) {
2967     return;
2968   }
2969 
2970   assert(Patching_lock->is_locked() ||
2971          SafepointSynchronize::is_at_safepoint(), "should be performed under a lock for consistency");
2972   oop installed_code = JNIHandles::resolve(_jvmci_installed_code);
2973   if (installed_code != NULL) {
2974     // Update the values in the InstalledCode instance if it still refers to this nmethod
2975     nmethod* nm = (nmethod*)InstalledCode::address(installed_code);
2976     if (nm == this) {
2977       if (!is_alive() || is_unloading()) {
2978         // Break the link between nmethod and InstalledCode such that the nmethod
2979         // can subsequently be flushed safely.  The link must be maintained while
2980         // the method could have live activations since invalidateInstalledCode
2981         // might want to invalidate all existing activations.
2982         InstalledCode::set_address(installed_code, 0);
2983         InstalledCode::set_entryPoint(installed_code, 0);
2984       } else if (is_not_entrant()) {
2985         // Remove the entry point so any invocation will fail but keep
2986         // the address link around that so that existing activations can
2987         // be invalidated.
2988         InstalledCode::set_entryPoint(installed_code, 0);
2989       }
2990     }
2991   }
2992   if (!is_alive() || is_unloading()) {
2993     // Clear these out after the nmethod has been unregistered and any
2994     // updates to the InstalledCode instance have been performed.
2995     clear_jvmci_installed_code();
2996     clear_speculation_log();
2997   }
2998 }
2999 
3000 void nmethod::invalidate_installed_code(Handle installedCode, TRAPS) {
3001   if (installedCode() == NULL) {
3002     THROW(vmSymbols::java_lang_NullPointerException());
3003   }
3004   jlong nativeMethod = InstalledCode::address(installedCode);
3005   nmethod* nm = (nmethod*)nativeMethod;
3006   if (nm == NULL) {
3007     // Nothing to do
3008     return;
3009   }
3010 
3011   nmethodLocker nml(nm);
3012 #ifdef ASSERT
3013   {
3014     MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
3015     // This relationship can only be checked safely under a lock
3016     assert(!nm->is_alive() || nm->is_unloading() || nm->jvmci_installed_code() == installedCode(), "sanity check");
3017   }
3018 #endif
3019 
3020   if (nm->is_alive()) {
3021     // Invalidating the InstalledCode means we want the nmethod
3022     // to be deoptimized.
3023     nm->mark_for_deoptimization();
3024     VM_Deoptimize op;
3025     VMThread::execute(&op);
3026   }
3027 
3028   // Multiple threads could reach this point so we now need to
3029   // lock and re-check the link to the nmethod so that only one
3030   // thread clears it.
3031   MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
3032   if (InstalledCode::address(installedCode) == nativeMethod) {
3033       InstalledCode::set_address(installedCode, 0);
3034   }
3035 }
3036 
3037 oop nmethod::jvmci_installed_code() {
3038   return JNIHandles::resolve(_jvmci_installed_code);
3039 }
3040 
3041 oop nmethod::speculation_log() {
3042   return JNIHandles::resolve(_speculation_log);
3043 }
3044 
3045 char* nmethod::jvmci_installed_code_name(char* buf, size_t buflen) const {
3046   if (!this->is_compiled_by_jvmci()) {
3047     return NULL;
3048   }
3049   oop installed_code = JNIHandles::resolve(_jvmci_installed_code);
3050   if (installed_code != NULL) {
3051     oop installed_code_name = NULL;
3052     if (installed_code->is_a(InstalledCode::klass())) {
3053       installed_code_name = InstalledCode::name(installed_code);
3054     }
3055     if (installed_code_name != NULL) {
3056       return java_lang_String::as_utf8_string(installed_code_name, buf, (int)buflen);
3057     }
3058   }
3059   return NULL;
3060 }
3061 #endif