1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "asm/assembler.inline.hpp"
  28 #include "code/codeCache.hpp"
  29 #include "code/compiledIC.hpp"
  30 #include "code/compiledMethod.inline.hpp"
  31 #include "code/dependencies.hpp"
  32 #include "code/nativeInst.hpp"
  33 #include "code/nmethod.hpp"
  34 #include "code/scopeDesc.hpp"
  35 #include "compiler/abstractCompiler.hpp"
  36 #include "compiler/compileBroker.hpp"
  37 #include "compiler/compileLog.hpp"
  38 #include "compiler/compilerDirectives.hpp"
  39 #include "compiler/directivesParser.hpp"
  40 #include "compiler/disassembler.hpp"
  41 #include "interpreter/bytecode.hpp"
  42 #include "logging/log.hpp"
  43 #include "logging/logStream.hpp"
  44 #include "memory/allocation.inline.hpp"
  45 #include "memory/resourceArea.hpp"
  46 #include "oops/access.inline.hpp"
  47 #include "oops/method.inline.hpp"
  48 #include "oops/methodData.hpp"
  49 #include "oops/oop.inline.hpp"
  50 #include "prims/jvmtiImpl.hpp"
  51 #include "runtime/atomic.hpp"
  52 #include "runtime/flags/flagSetting.hpp"
  53 #include "runtime/frame.inline.hpp"
  54 #include "runtime/handles.inline.hpp"
  55 #include "runtime/jniHandles.inline.hpp"
  56 #include "runtime/orderAccess.hpp"
  57 #include "runtime/os.hpp"
  58 #include "runtime/safepointVerifiers.hpp"
  59 #include "runtime/sharedRuntime.hpp"
  60 #include "runtime/sweeper.hpp"
  61 #include "runtime/vmThread.hpp"
  62 #include "utilities/align.hpp"
  63 #include "utilities/dtrace.hpp"
  64 #include "utilities/events.hpp"
  65 #include "utilities/resourceHash.hpp"
  66 #include "utilities/xmlstream.hpp"
  67 #if INCLUDE_JVMCI
  68 #include "jvmci/jvmciRuntime.hpp"
  69 #endif
  70 
  71 #ifdef DTRACE_ENABLED
  72 
  73 // Only bother with this argument setup if dtrace is available
  74 
  75 #define DTRACE_METHOD_UNLOAD_PROBE(method)                                \
  76   {                                                                       \
  77     Method* m = (method);                                                 \
  78     if (m != NULL) {                                                      \
  79       Symbol* klass_name = m->klass_name();                               \
  80       Symbol* name = m->name();                                           \
  81       Symbol* signature = m->signature();                                 \
  82       HOTSPOT_COMPILED_METHOD_UNLOAD(                                     \
  83         (char *) klass_name->bytes(), klass_name->utf8_length(),                   \
  84         (char *) name->bytes(), name->utf8_length(),                               \
  85         (char *) signature->bytes(), signature->utf8_length());                    \
  86     }                                                                     \
  87   }
  88 
  89 #else //  ndef DTRACE_ENABLED
  90 
  91 #define DTRACE_METHOD_UNLOAD_PROBE(method)
  92 
  93 #endif
  94 
  95 //---------------------------------------------------------------------------------
  96 // NMethod statistics
  97 // They are printed under various flags, including:
  98 //   PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
  99 // (In the latter two cases, they like other stats are printed to the log only.)
 100 
 101 #ifndef PRODUCT
 102 // These variables are put into one block to reduce relocations
 103 // and make it simpler to print from the debugger.
 104 struct java_nmethod_stats_struct {
 105   int nmethod_count;
 106   int total_size;
 107   int relocation_size;
 108   int consts_size;
 109   int insts_size;
 110   int stub_size;
 111   int scopes_data_size;
 112   int scopes_pcs_size;
 113   int dependencies_size;
 114   int handler_table_size;
 115   int nul_chk_table_size;
 116 #if INCLUDE_JVMCI
 117   int speculations_size;
 118   int jvmci_data_size;
 119 #endif
 120   int oops_size;
 121   int metadata_size;
 122 
 123   void note_nmethod(nmethod* nm) {
 124     nmethod_count += 1;
 125     total_size          += nm->size();
 126     relocation_size     += nm->relocation_size();
 127     consts_size         += nm->consts_size();
 128     insts_size          += nm->insts_size();
 129     stub_size           += nm->stub_size();
 130     oops_size           += nm->oops_size();
 131     metadata_size       += nm->metadata_size();
 132     scopes_data_size    += nm->scopes_data_size();
 133     scopes_pcs_size     += nm->scopes_pcs_size();
 134     dependencies_size   += nm->dependencies_size();
 135     handler_table_size  += nm->handler_table_size();
 136     nul_chk_table_size  += nm->nul_chk_table_size();
 137 #if INCLUDE_JVMCI
 138     speculations_size   += nm->speculations_size();
 139     jvmci_data_size     += nm->jvmci_data_size();
 140 #endif
 141   }
 142   void print_nmethod_stats(const char* name) {
 143     if (nmethod_count == 0)  return;
 144     tty->print_cr("Statistics for %d bytecoded nmethods for %s:", nmethod_count, name);
 145     if (total_size != 0)          tty->print_cr(" total in heap  = %d", total_size);
 146     if (nmethod_count != 0)       tty->print_cr(" header         = " SIZE_FORMAT, nmethod_count * sizeof(nmethod));
 147     if (relocation_size != 0)     tty->print_cr(" relocation     = %d", relocation_size);
 148     if (consts_size != 0)         tty->print_cr(" constants      = %d", consts_size);
 149     if (insts_size != 0)          tty->print_cr(" main code      = %d", insts_size);
 150     if (stub_size != 0)           tty->print_cr(" stub code      = %d", stub_size);
 151     if (oops_size != 0)           tty->print_cr(" oops           = %d", oops_size);
 152     if (metadata_size != 0)       tty->print_cr(" metadata       = %d", metadata_size);
 153     if (scopes_data_size != 0)    tty->print_cr(" scopes data    = %d", scopes_data_size);
 154     if (scopes_pcs_size != 0)     tty->print_cr(" scopes pcs     = %d", scopes_pcs_size);
 155     if (dependencies_size != 0)   tty->print_cr(" dependencies   = %d", dependencies_size);
 156     if (handler_table_size != 0)  tty->print_cr(" handler table  = %d", handler_table_size);
 157     if (nul_chk_table_size != 0)  tty->print_cr(" nul chk table  = %d", nul_chk_table_size);
 158 #if INCLUDE_JVMCI
 159     if (speculations_size != 0)   tty->print_cr(" speculations   = %d", speculations_size);
 160     if (jvmci_data_size != 0)     tty->print_cr(" JVMCI data     = %d", jvmci_data_size);
 161 #endif
 162   }
 163 };
 164 
 165 struct native_nmethod_stats_struct {
 166   int native_nmethod_count;
 167   int native_total_size;
 168   int native_relocation_size;
 169   int native_insts_size;
 170   int native_oops_size;
 171   int native_metadata_size;
 172   void note_native_nmethod(nmethod* nm) {
 173     native_nmethod_count += 1;
 174     native_total_size       += nm->size();
 175     native_relocation_size  += nm->relocation_size();
 176     native_insts_size       += nm->insts_size();
 177     native_oops_size        += nm->oops_size();
 178     native_metadata_size    += nm->metadata_size();
 179   }
 180   void print_native_nmethod_stats() {
 181     if (native_nmethod_count == 0)  return;
 182     tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
 183     if (native_total_size != 0)       tty->print_cr(" N. total size  = %d", native_total_size);
 184     if (native_relocation_size != 0)  tty->print_cr(" N. relocation  = %d", native_relocation_size);
 185     if (native_insts_size != 0)       tty->print_cr(" N. main code   = %d", native_insts_size);
 186     if (native_oops_size != 0)        tty->print_cr(" N. oops        = %d", native_oops_size);
 187     if (native_metadata_size != 0)    tty->print_cr(" N. metadata    = %d", native_metadata_size);
 188   }
 189 };
 190 
 191 struct pc_nmethod_stats_struct {
 192   int pc_desc_resets;   // number of resets (= number of caches)
 193   int pc_desc_queries;  // queries to nmethod::find_pc_desc
 194   int pc_desc_approx;   // number of those which have approximate true
 195   int pc_desc_repeats;  // number of _pc_descs[0] hits
 196   int pc_desc_hits;     // number of LRU cache hits
 197   int pc_desc_tests;    // total number of PcDesc examinations
 198   int pc_desc_searches; // total number of quasi-binary search steps
 199   int pc_desc_adds;     // number of LUR cache insertions
 200 
 201   void print_pc_stats() {
 202     tty->print_cr("PcDesc Statistics:  %d queries, %.2f comparisons per query",
 203                   pc_desc_queries,
 204                   (double)(pc_desc_tests + pc_desc_searches)
 205                   / pc_desc_queries);
 206     tty->print_cr("  caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
 207                   pc_desc_resets,
 208                   pc_desc_queries, pc_desc_approx,
 209                   pc_desc_repeats, pc_desc_hits,
 210                   pc_desc_tests, pc_desc_searches, pc_desc_adds);
 211   }
 212 };
 213 
 214 #ifdef COMPILER1
 215 static java_nmethod_stats_struct c1_java_nmethod_stats;
 216 #endif
 217 #ifdef COMPILER2
 218 static java_nmethod_stats_struct c2_java_nmethod_stats;
 219 #endif
 220 #if INCLUDE_JVMCI
 221 static java_nmethod_stats_struct jvmci_java_nmethod_stats;
 222 #endif
 223 static java_nmethod_stats_struct unknown_java_nmethod_stats;
 224 
 225 static native_nmethod_stats_struct native_nmethod_stats;
 226 static pc_nmethod_stats_struct pc_nmethod_stats;
 227 
 228 static void note_java_nmethod(nmethod* nm) {
 229 #ifdef COMPILER1
 230   if (nm->is_compiled_by_c1()) {
 231     c1_java_nmethod_stats.note_nmethod(nm);
 232   } else
 233 #endif
 234 #ifdef COMPILER2
 235   if (nm->is_compiled_by_c2()) {
 236     c2_java_nmethod_stats.note_nmethod(nm);
 237   } else
 238 #endif
 239 #if INCLUDE_JVMCI
 240   if (nm->is_compiled_by_jvmci()) {
 241     jvmci_java_nmethod_stats.note_nmethod(nm);
 242   } else
 243 #endif
 244   {
 245     unknown_java_nmethod_stats.note_nmethod(nm);
 246   }
 247 }
 248 #endif // !PRODUCT
 249 
 250 //---------------------------------------------------------------------------------
 251 
 252 
 253 ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
 254   assert(pc != NULL, "Must be non null");
 255   assert(exception.not_null(), "Must be non null");
 256   assert(handler != NULL, "Must be non null");
 257 
 258   _count = 0;
 259   _exception_type = exception->klass();
 260   _next = NULL;
 261   _purge_list_next = NULL;
 262 
 263   add_address_and_handler(pc,handler);
 264 }
 265 
 266 
 267 address ExceptionCache::match(Handle exception, address pc) {
 268   assert(pc != NULL,"Must be non null");
 269   assert(exception.not_null(),"Must be non null");
 270   if (exception->klass() == exception_type()) {
 271     return (test_address(pc));
 272   }
 273 
 274   return NULL;
 275 }
 276 
 277 
 278 bool ExceptionCache::match_exception_with_space(Handle exception) {
 279   assert(exception.not_null(),"Must be non null");
 280   if (exception->klass() == exception_type() && count() < cache_size) {
 281     return true;
 282   }
 283   return false;
 284 }
 285 
 286 
 287 address ExceptionCache::test_address(address addr) {
 288   int limit = count();
 289   for (int i = 0; i < limit; i++) {
 290     if (pc_at(i) == addr) {
 291       return handler_at(i);
 292     }
 293   }
 294   return NULL;
 295 }
 296 
 297 
 298 bool ExceptionCache::add_address_and_handler(address addr, address handler) {
 299   if (test_address(addr) == handler) return true;
 300 
 301   int index = count();
 302   if (index < cache_size) {
 303     set_pc_at(index, addr);
 304     set_handler_at(index, handler);
 305     increment_count();
 306     return true;
 307   }
 308   return false;
 309 }
 310 
 311 ExceptionCache* ExceptionCache::next() {
 312   return Atomic::load(&_next);
 313 }
 314 
 315 void ExceptionCache::set_next(ExceptionCache *ec) {
 316   Atomic::store(ec, &_next);
 317 }
 318 
 319 //-----------------------------------------------------------------------------
 320 
 321 
 322 // Helper used by both find_pc_desc methods.
 323 static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
 324   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_tests);
 325   if (!approximate)
 326     return pc->pc_offset() == pc_offset;
 327   else
 328     return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
 329 }
 330 
 331 void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
 332   if (initial_pc_desc == NULL) {
 333     _pc_descs[0] = NULL; // native method; no PcDescs at all
 334     return;
 335   }
 336   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_resets);
 337   // reset the cache by filling it with benign (non-null) values
 338   assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
 339   for (int i = 0; i < cache_size; i++)
 340     _pc_descs[i] = initial_pc_desc;
 341 }
 342 
 343 PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
 344   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_queries);
 345   NOT_PRODUCT(if (approximate) ++pc_nmethod_stats.pc_desc_approx);
 346 
 347   // Note: one might think that caching the most recently
 348   // read value separately would be a win, but one would be
 349   // wrong.  When many threads are updating it, the cache
 350   // line it's in would bounce between caches, negating
 351   // any benefit.
 352 
 353   // In order to prevent race conditions do not load cache elements
 354   // repeatedly, but use a local copy:
 355   PcDesc* res;
 356 
 357   // Step one:  Check the most recently added value.
 358   res = _pc_descs[0];
 359   if (res == NULL) return NULL;  // native method; no PcDescs at all
 360   if (match_desc(res, pc_offset, approximate)) {
 361     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_repeats);
 362     return res;
 363   }
 364 
 365   // Step two:  Check the rest of the LRU cache.
 366   for (int i = 1; i < cache_size; ++i) {
 367     res = _pc_descs[i];
 368     if (res->pc_offset() < 0) break;  // optimization: skip empty cache
 369     if (match_desc(res, pc_offset, approximate)) {
 370       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_hits);
 371       return res;
 372     }
 373   }
 374 
 375   // Report failure.
 376   return NULL;
 377 }
 378 
 379 void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
 380   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_adds);
 381   // Update the LRU cache by shifting pc_desc forward.
 382   for (int i = 0; i < cache_size; i++)  {
 383     PcDesc* next = _pc_descs[i];
 384     _pc_descs[i] = pc_desc;
 385     pc_desc = next;
 386   }
 387 }
 388 
 389 // adjust pcs_size so that it is a multiple of both oopSize and
 390 // sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
 391 // of oopSize, then 2*sizeof(PcDesc) is)
 392 static int adjust_pcs_size(int pcs_size) {
 393   int nsize = align_up(pcs_size,   oopSize);
 394   if ((nsize % sizeof(PcDesc)) != 0) {
 395     nsize = pcs_size + sizeof(PcDesc);
 396   }
 397   assert((nsize % oopSize) == 0, "correct alignment");
 398   return nsize;
 399 }
 400 
 401 
 402 int nmethod::total_size() const {
 403   return
 404     consts_size()        +
 405     insts_size()         +
 406     stub_size()          +
 407     scopes_data_size()   +
 408     scopes_pcs_size()    +
 409     handler_table_size() +
 410     nul_chk_table_size();
 411 }
 412 
 413 address* nmethod::orig_pc_addr(const frame* fr) {
 414   return (address*) ((address)fr->unextended_sp() + _orig_pc_offset);
 415 }
 416 
 417 const char* nmethod::compile_kind() const {
 418   if (is_osr_method())     return "osr";
 419   if (method() != NULL && is_native_method())  return "c2n";
 420   return NULL;
 421 }
 422 
 423 // Fill in default values for various flag fields
 424 void nmethod::init_defaults() {
 425   _state                      = not_installed;
 426   _has_flushed_dependencies   = 0;
 427   _lock_count                 = 0;
 428   _stack_traversal_mark       = 0;
 429   _unload_reported            = false; // jvmti state
 430   _is_far_code                = false; // nmethods are located in CodeCache
 431 
 432 #ifdef ASSERT
 433   _oops_are_stale             = false;
 434 #endif
 435 
 436   _oops_do_mark_link       = NULL;
 437   _jmethod_id              = NULL;
 438   _osr_link                = NULL;
 439 #if INCLUDE_RTM_OPT
 440   _rtm_state               = NoRTM;
 441 #endif
 442 }
 443 
 444 nmethod* nmethod::new_native_nmethod(const methodHandle& method,
 445   int compile_id,
 446   CodeBuffer *code_buffer,
 447   int vep_offset,
 448   int frame_complete,
 449   int frame_size,
 450   ByteSize basic_lock_owner_sp_offset,
 451   ByteSize basic_lock_sp_offset,
 452   OopMapSet* oop_maps) {
 453   code_buffer->finalize_oop_references(method);
 454   // create nmethod
 455   nmethod* nm = NULL;
 456   {
 457     MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 458     int native_nmethod_size = CodeBlob::allocation_size(code_buffer, sizeof(nmethod));
 459 
 460     CodeOffsets offsets;
 461     offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
 462     offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
 463     nm = new (native_nmethod_size, CompLevel_none)
 464     nmethod(method(), compiler_none, native_nmethod_size,
 465             compile_id, &offsets,
 466             code_buffer, frame_size,
 467             basic_lock_owner_sp_offset,
 468             basic_lock_sp_offset,
 469             oop_maps);
 470     NOT_PRODUCT(if (nm != NULL)  native_nmethod_stats.note_native_nmethod(nm));
 471   }
 472 
 473   if (nm != NULL) {
 474     // verify nmethod
 475     debug_only(nm->verify();) // might block
 476 
 477     nm->log_new_nmethod();
 478     nm->make_in_use();
 479   }
 480   return nm;
 481 }
 482 
 483 nmethod* nmethod::new_nmethod(const methodHandle& method,
 484   int compile_id,
 485   int entry_bci,
 486   CodeOffsets* offsets,
 487   int orig_pc_offset,
 488   DebugInformationRecorder* debug_info,
 489   Dependencies* dependencies,
 490   CodeBuffer* code_buffer, int frame_size,
 491   OopMapSet* oop_maps,
 492   ExceptionHandlerTable* handler_table,
 493   ImplicitExceptionTable* nul_chk_table,
 494   AbstractCompiler* compiler,
 495   int comp_level
 496 #if INCLUDE_JVMCI
 497   , char* speculations,
 498   int speculations_len,
 499   int nmethod_mirror_index,
 500   const char* nmethod_mirror_name,
 501   FailedSpeculation** failed_speculations
 502 #endif
 503 )
 504 {
 505   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 506   code_buffer->finalize_oop_references(method);
 507   // create nmethod
 508   nmethod* nm = NULL;
 509   { MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
 510 #if INCLUDE_JVMCI
 511     int jvmci_data_size = !compiler->is_jvmci() ? 0 : JVMCINMethodData::compute_size(nmethod_mirror_name);
 512 #endif
 513     int nmethod_size =
 514       CodeBlob::allocation_size(code_buffer, sizeof(nmethod))
 515       + adjust_pcs_size(debug_info->pcs_size())
 516       + align_up((int)dependencies->size_in_bytes(), oopSize)
 517       + align_up(handler_table->size_in_bytes()    , oopSize)
 518       + align_up(nul_chk_table->size_in_bytes()    , oopSize)
 519 #if INCLUDE_JVMCI
 520       + align_up(speculations_len                  , oopSize)
 521       + align_up(jvmci_data_size                   , oopSize)
 522 #endif
 523       + align_up(debug_info->data_size()           , oopSize);
 524 
 525     nm = new (nmethod_size, comp_level)
 526     nmethod(method(), compiler->type(), nmethod_size, compile_id, entry_bci, offsets,
 527             orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
 528             oop_maps,
 529             handler_table,
 530             nul_chk_table,
 531             compiler,
 532             comp_level
 533 #if INCLUDE_JVMCI
 534             , speculations,
 535             speculations_len,
 536             jvmci_data_size
 537 #endif
 538             );
 539 
 540     if (nm != NULL) {
 541 #if INCLUDE_JVMCI
 542       if (compiler->is_jvmci()) {
 543         // Initialize the JVMCINMethodData object inlined into nm
 544         nm->jvmci_nmethod_data()->initialize(nmethod_mirror_index, nmethod_mirror_name, failed_speculations);
 545       }
 546 #endif
 547       // To make dependency checking during class loading fast, record
 548       // the nmethod dependencies in the classes it is dependent on.
 549       // This allows the dependency checking code to simply walk the
 550       // class hierarchy above the loaded class, checking only nmethods
 551       // which are dependent on those classes.  The slow way is to
 552       // check every nmethod for dependencies which makes it linear in
 553       // the number of methods compiled.  For applications with a lot
 554       // classes the slow way is too slow.
 555       for (Dependencies::DepStream deps(nm); deps.next(); ) {
 556         if (deps.type() == Dependencies::call_site_target_value) {
 557           // CallSite dependencies are managed on per-CallSite instance basis.
 558           oop call_site = deps.argument_oop(0);
 559           MethodHandles::add_dependent_nmethod(call_site, nm);
 560         } else {
 561           Klass* klass = deps.context_type();
 562           if (klass == NULL) {
 563             continue;  // ignore things like evol_method
 564           }
 565           // record this nmethod as dependent on this klass
 566           InstanceKlass::cast(klass)->add_dependent_nmethod(nm);
 567         }
 568       }
 569       NOT_PRODUCT(if (nm != NULL)  note_java_nmethod(nm));
 570     }
 571   }
 572   // Do verification and logging outside CodeCache_lock.
 573   if (nm != NULL) {
 574     // Safepoints in nmethod::verify aren't allowed because nm hasn't been installed yet.
 575     DEBUG_ONLY(nm->verify();)
 576     nm->log_new_nmethod();
 577   }
 578   return nm;
 579 }
 580 
 581 // For native wrappers
 582 nmethod::nmethod(
 583   Method* method,
 584   CompilerType type,
 585   int nmethod_size,
 586   int compile_id,
 587   CodeOffsets* offsets,
 588   CodeBuffer* code_buffer,
 589   int frame_size,
 590   ByteSize basic_lock_owner_sp_offset,
 591   ByteSize basic_lock_sp_offset,
 592   OopMapSet* oop_maps )
 593   : CompiledMethod(method, "native nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 594   _is_unloading_state(0),
 595   _native_receiver_sp_offset(basic_lock_owner_sp_offset),
 596   _native_basic_lock_sp_offset(basic_lock_sp_offset)
 597 {
 598   {
 599     int scopes_data_offset   = 0;
 600     int deoptimize_offset    = 0;
 601     int deoptimize_mh_offset = 0;
 602 
 603     debug_only(NoSafepointVerifier nsv;)
 604     assert_locked_or_safepoint(CodeCache_lock);
 605 
 606     init_defaults();
 607     _entry_bci               = InvocationEntryBci;
 608     // We have no exception handler or deopt handler make the
 609     // values something that will never match a pc like the nmethod vtable entry
 610     _exception_offset        = 0;
 611     _orig_pc_offset          = 0;
 612 
 613     _consts_offset           = data_offset();
 614     _stub_offset             = data_offset();
 615     _oops_offset             = data_offset();
 616     _metadata_offset         = _oops_offset         + align_up(code_buffer->total_oop_size(), oopSize);
 617     scopes_data_offset       = _metadata_offset     + align_up(code_buffer->total_metadata_size(), wordSize);
 618     _scopes_pcs_offset       = scopes_data_offset;
 619     _dependencies_offset     = _scopes_pcs_offset;
 620     _handler_table_offset    = _dependencies_offset;
 621     _nul_chk_table_offset    = _handler_table_offset;
 622 #if INCLUDE_JVMCI
 623     _speculations_offset     = _nul_chk_table_offset;
 624     _jvmci_data_offset       = _speculations_offset;
 625     _nmethod_end_offset      = _jvmci_data_offset;
 626 #else
 627     _nmethod_end_offset      = _nul_chk_table_offset;
 628 #endif
 629     _compile_id              = compile_id;
 630     _comp_level              = CompLevel_none;
 631     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 632     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 633     _osr_entry_point         = NULL;
 634     _exception_cache         = NULL;
 635     _pc_desc_container.reset_to(NULL);
 636     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 637 
 638     _scopes_data_begin = (address) this + scopes_data_offset;
 639     _deopt_handler_begin = (address) this + deoptimize_offset;
 640     _deopt_mh_handler_begin = (address) this + deoptimize_mh_offset;
 641 
 642     code_buffer->copy_code_and_locs_to(this);
 643     code_buffer->copy_values_to(this);
 644 
 645     clear_unloading_state();
 646 
 647     Universe::heap()->register_nmethod(this);
 648     debug_only(Universe::heap()->verify_nmethod(this));
 649 
 650     CodeCache::commit(this);
 651   }
 652 
 653   if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
 654     ttyLocker ttyl;  // keep the following output all in one block
 655     // This output goes directly to the tty, not the compiler log.
 656     // To enable tools to match it up with the compilation activity,
 657     // be sure to tag this tty output with the compile ID.
 658     if (xtty != NULL) {
 659       xtty->begin_head("print_native_nmethod");
 660       xtty->method(_method);
 661       xtty->stamp();
 662       xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
 663     }
 664     // Print the header part, then print the requested information.
 665     // This is both handled in decode2(), called via print_code() -> decode()
 666     if (PrintNativeNMethods) {
 667       tty->print_cr("-------------------------- Assembly (native nmethod) ---------------------------");
 668       print_code();
 669       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 670 #if defined(SUPPORT_DATA_STRUCTS)
 671       if (AbstractDisassembler::show_structs()) {
 672         if (oop_maps != NULL) {
 673           tty->print("oop maps:"); // oop_maps->print_on(tty) outputs a cr() at the beginning
 674           oop_maps->print_on(tty);
 675           tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 676         }
 677       }
 678 #endif
 679     } else {
 680       print(); // print the header part only.
 681     }
 682 #if defined(SUPPORT_DATA_STRUCTS)
 683     if (AbstractDisassembler::show_structs()) {
 684       if (PrintRelocations) {
 685         print_relocations();
 686         tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 687       }
 688     }
 689 #endif
 690     if (xtty != NULL) {
 691       xtty->tail("print_native_nmethod");
 692     }
 693   }
 694 }
 695 
 696 void* nmethod::operator new(size_t size, int nmethod_size, int comp_level) throw () {
 697   return CodeCache::allocate(nmethod_size, CodeCache::get_code_blob_type(comp_level));
 698 }
 699 
 700 nmethod::nmethod(
 701   Method* method,
 702   CompilerType type,
 703   int nmethod_size,
 704   int compile_id,
 705   int entry_bci,
 706   CodeOffsets* offsets,
 707   int orig_pc_offset,
 708   DebugInformationRecorder* debug_info,
 709   Dependencies* dependencies,
 710   CodeBuffer *code_buffer,
 711   int frame_size,
 712   OopMapSet* oop_maps,
 713   ExceptionHandlerTable* handler_table,
 714   ImplicitExceptionTable* nul_chk_table,
 715   AbstractCompiler* compiler,
 716   int comp_level
 717 #if INCLUDE_JVMCI
 718   , char* speculations,
 719   int speculations_len,
 720   int jvmci_data_size
 721 #endif
 722   )
 723   : CompiledMethod(method, "nmethod", type, nmethod_size, sizeof(nmethod), code_buffer, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps, false),
 724   _is_unloading_state(0),
 725   _native_receiver_sp_offset(in_ByteSize(-1)),
 726   _native_basic_lock_sp_offset(in_ByteSize(-1))
 727 {
 728   assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
 729   {
 730     debug_only(NoSafepointVerifier nsv;)
 731     assert_locked_or_safepoint(CodeCache_lock);
 732 
 733     _deopt_handler_begin = (address) this;
 734     _deopt_mh_handler_begin = (address) this;
 735 
 736     init_defaults();
 737     _entry_bci               = entry_bci;
 738     _compile_id              = compile_id;
 739     _comp_level              = comp_level;
 740     _orig_pc_offset          = orig_pc_offset;
 741     _hotness_counter         = NMethodSweeper::hotness_counter_reset_val();
 742 
 743     // Section offsets
 744     _consts_offset           = content_offset()      + code_buffer->total_offset_of(code_buffer->consts());
 745     _stub_offset             = content_offset()      + code_buffer->total_offset_of(code_buffer->stubs());
 746     set_ctable_begin(header_begin() + _consts_offset);
 747 
 748 #if INCLUDE_JVMCI
 749     if (compiler->is_jvmci()) {
 750       // JVMCI might not produce any stub sections
 751       if (offsets->value(CodeOffsets::Exceptions) != -1) {
 752         _exception_offset        = code_offset()          + offsets->value(CodeOffsets::Exceptions);
 753       } else {
 754         _exception_offset = -1;
 755       }
 756       if (offsets->value(CodeOffsets::Deopt) != -1) {
 757         _deopt_handler_begin       = (address) this + code_offset()          + offsets->value(CodeOffsets::Deopt);
 758       } else {
 759         _deopt_handler_begin = NULL;
 760       }
 761       if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 762         _deopt_mh_handler_begin  = (address) this + code_offset()          + offsets->value(CodeOffsets::DeoptMH);
 763       } else {
 764         _deopt_mh_handler_begin = NULL;
 765       }
 766     } else
 767 #endif
 768     {
 769       // Exception handler and deopt handler are in the stub section
 770       assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
 771       assert(offsets->value(CodeOffsets::Deopt     ) != -1, "must be set");
 772 
 773       _exception_offset       = _stub_offset          + offsets->value(CodeOffsets::Exceptions);
 774       _deopt_handler_begin    = (address) this + _stub_offset          + offsets->value(CodeOffsets::Deopt);
 775       if (offsets->value(CodeOffsets::DeoptMH) != -1) {
 776         _deopt_mh_handler_begin  = (address) this + _stub_offset          + offsets->value(CodeOffsets::DeoptMH);
 777       } else {
 778         _deopt_mh_handler_begin  = NULL;
 779       }
 780     }
 781     if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
 782       _unwind_handler_offset = code_offset()         + offsets->value(CodeOffsets::UnwindHandler);
 783     } else {
 784       _unwind_handler_offset = -1;
 785     }
 786 
 787     _oops_offset             = data_offset();
 788     _metadata_offset         = _oops_offset          + align_up(code_buffer->total_oop_size(), oopSize);
 789     int scopes_data_offset   = _metadata_offset      + align_up(code_buffer->total_metadata_size(), wordSize);
 790 
 791     _scopes_pcs_offset       = scopes_data_offset    + align_up(debug_info->data_size       (), oopSize);
 792     _dependencies_offset     = _scopes_pcs_offset    + adjust_pcs_size(debug_info->pcs_size());
 793     _handler_table_offset    = _dependencies_offset  + align_up((int)dependencies->size_in_bytes (), oopSize);
 794     _nul_chk_table_offset    = _handler_table_offset + align_up(handler_table->size_in_bytes(), oopSize);
 795 #if INCLUDE_JVMCI
 796     _speculations_offset     = _nul_chk_table_offset + align_up(nul_chk_table->size_in_bytes(), oopSize);
 797     _jvmci_data_offset       = _speculations_offset  + align_up(speculations_len, oopSize);
 798     _nmethod_end_offset      = _jvmci_data_offset    + align_up(jvmci_data_size, oopSize);
 799 #else
 800     _nmethod_end_offset      = _nul_chk_table_offset + align_up(nul_chk_table->size_in_bytes(), oopSize);
 801 #endif
 802     _entry_point             = code_begin()          + offsets->value(CodeOffsets::Entry);
 803     _verified_entry_point    = code_begin()          + offsets->value(CodeOffsets::Verified_Entry);
 804     _osr_entry_point         = code_begin()          + offsets->value(CodeOffsets::OSR_Entry);
 805     _exception_cache         = NULL;
 806     _scopes_data_begin       = (address) this + scopes_data_offset;
 807 
 808     _pc_desc_container.reset_to(scopes_pcs_begin());
 809 
 810     code_buffer->copy_code_and_locs_to(this);
 811     // Copy contents of ScopeDescRecorder to nmethod
 812     code_buffer->copy_values_to(this);
 813     debug_info->copy_to(this);
 814     dependencies->copy_to(this);
 815     clear_unloading_state();
 816 
 817     Universe::heap()->register_nmethod(this);
 818     debug_only(Universe::heap()->verify_nmethod(this));
 819 
 820     CodeCache::commit(this);
 821 
 822     // Copy contents of ExceptionHandlerTable to nmethod
 823     handler_table->copy_to(this);
 824     nul_chk_table->copy_to(this);
 825 
 826 #if INCLUDE_JVMCI
 827     // Copy speculations to nmethod
 828     if (speculations_size() != 0) {
 829       memcpy(speculations_begin(), speculations, speculations_len);
 830     }
 831 #endif
 832 
 833     // we use the information of entry points to find out if a method is
 834     // static or non static
 835     assert(compiler->is_c2() || compiler->is_jvmci() ||
 836            _method->is_static() == (entry_point() == _verified_entry_point),
 837            " entry points must be same for static methods and vice versa");
 838   }
 839 }
 840 
 841 // Print a short set of xml attributes to identify this nmethod.  The
 842 // output should be embedded in some other element.
 843 void nmethod::log_identity(xmlStream* log) const {
 844   log->print(" compile_id='%d'", compile_id());
 845   const char* nm_kind = compile_kind();
 846   if (nm_kind != NULL)  log->print(" compile_kind='%s'", nm_kind);
 847   log->print(" compiler='%s'", compiler_name());
 848   if (TieredCompilation) {
 849     log->print(" level='%d'", comp_level());
 850   }
 851 #if INCLUDE_JVMCI
 852   if (jvmci_nmethod_data() != NULL) {
 853     const char* jvmci_name = jvmci_nmethod_data()->name();
 854     if (jvmci_name != NULL) {
 855       log->print(" jvmci_mirror_name='");
 856       log->text("%s", jvmci_name);
 857       log->print("'");
 858     }
 859   }
 860 #endif
 861 }
 862 
 863 
 864 #define LOG_OFFSET(log, name)                    \
 865   if (p2i(name##_end()) - p2i(name##_begin())) \
 866     log->print(" " XSTR(name) "_offset='" INTX_FORMAT "'"    , \
 867                p2i(name##_begin()) - p2i(this))
 868 
 869 
 870 void nmethod::log_new_nmethod() const {
 871   if (LogCompilation && xtty != NULL) {
 872     ttyLocker ttyl;
 873     HandleMark hm;
 874     xtty->begin_elem("nmethod");
 875     log_identity(xtty);
 876     xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", p2i(code_begin()), size());
 877     xtty->print(" address='" INTPTR_FORMAT "'", p2i(this));
 878 
 879     LOG_OFFSET(xtty, relocation);
 880     LOG_OFFSET(xtty, consts);
 881     LOG_OFFSET(xtty, insts);
 882     LOG_OFFSET(xtty, stub);
 883     LOG_OFFSET(xtty, scopes_data);
 884     LOG_OFFSET(xtty, scopes_pcs);
 885     LOG_OFFSET(xtty, dependencies);
 886     LOG_OFFSET(xtty, handler_table);
 887     LOG_OFFSET(xtty, nul_chk_table);
 888     LOG_OFFSET(xtty, oops);
 889     LOG_OFFSET(xtty, metadata);
 890 
 891     xtty->method(method());
 892     xtty->stamp();
 893     xtty->end_elem();
 894   }
 895 }
 896 
 897 #undef LOG_OFFSET
 898 
 899 
 900 // Print out more verbose output usually for a newly created nmethod.
 901 void nmethod::print_on(outputStream* st, const char* msg) const {
 902   if (st != NULL) {
 903     ttyLocker ttyl;
 904     if (WizardMode) {
 905       CompileTask::print(st, this, msg, /*short_form:*/ true);
 906       st->print_cr(" (" INTPTR_FORMAT ")", p2i(this));
 907     } else {
 908       CompileTask::print(st, this, msg, /*short_form:*/ false);
 909     }
 910   }
 911 }
 912 
 913 void nmethod::maybe_print_nmethod(DirectiveSet* directive) {
 914   bool printnmethods = directive->PrintAssemblyOption || directive->PrintNMethodsOption;
 915   if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
 916     print_nmethod(printnmethods);
 917   }
 918 }
 919 
 920 void nmethod::print_nmethod(bool printmethod) {
 921   ttyLocker ttyl;  // keep the following output all in one block
 922   if (xtty != NULL) {
 923     xtty->begin_head("print_nmethod");
 924     xtty->stamp();
 925     xtty->end_head();
 926   }
 927   // Print the header part, then print the requested information.
 928   // This is both handled in decode2().
 929   if (printmethod) {
 930     HandleMark hm;
 931     ResourceMark m;
 932     if (is_compiled_by_c1()) {
 933       tty->cr();
 934       tty->print_cr("============================= C1-compiled nmethod ==============================");
 935     }
 936     if (is_compiled_by_jvmci()) {
 937       tty->cr();
 938       tty->print_cr("=========================== JVMCI-compiled nmethod =============================");
 939     }
 940     tty->print_cr("----------------------------------- Assembly -----------------------------------");
 941     decode2(tty);
 942 #if defined(SUPPORT_DATA_STRUCTS)
 943     if (AbstractDisassembler::show_structs()) {
 944       // Print the oops from the underlying CodeBlob as well.
 945       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 946       print_oops(tty);
 947       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 948       print_metadata(tty);
 949       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 950       print_pcs();
 951       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 952       if (oop_maps() != NULL) {
 953         tty->print("oop maps:"); // oop_maps()->print_on(tty) outputs a cr() at the beginning
 954         oop_maps()->print_on(tty);
 955         tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 956       }
 957     }
 958 #endif
 959   } else {
 960     print(); // print the header part only.
 961   }
 962 
 963 #if defined(SUPPORT_DATA_STRUCTS)
 964   if (AbstractDisassembler::show_structs()) {
 965     if (printmethod || PrintDebugInfo || CompilerOracle::has_option_string(_method, "PrintDebugInfo")) {
 966       print_scopes();
 967       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 968     }
 969     if (printmethod || PrintRelocations || CompilerOracle::has_option_string(_method, "PrintRelocations")) {
 970       print_relocations();
 971       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 972     }
 973     if (printmethod || PrintDependencies || CompilerOracle::has_option_string(_method, "PrintDependencies")) {
 974       print_dependencies();
 975       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 976     }
 977     if (printmethod || PrintExceptionHandlers) {
 978       print_handler_table();
 979       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 980       print_nul_chk_table();
 981       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 982     }
 983 
 984     if (printmethod) {
 985       print_recorded_oops();
 986       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 987       print_recorded_metadata();
 988       tty->print_cr("- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ");
 989     }
 990   }
 991 #endif
 992 
 993   if (xtty != NULL) {
 994     xtty->tail("print_nmethod");
 995   }
 996 }
 997 
 998 
 999 // Promote one word from an assembly-time handle to a live embedded oop.
1000 inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
1001   if (handle == NULL ||
1002       // As a special case, IC oops are initialized to 1 or -1.
1003       handle == (jobject) Universe::non_oop_word()) {
1004     (*dest) = (oop) handle;
1005   } else {
1006     (*dest) = JNIHandles::resolve_non_null(handle);
1007   }
1008 }
1009 
1010 
1011 // Have to have the same name because it's called by a template
1012 void nmethod::copy_values(GrowableArray<jobject>* array) {
1013   int length = array->length();
1014   assert((address)(oops_begin() + length) <= (address)oops_end(), "oops big enough");
1015   oop* dest = oops_begin();
1016   for (int index = 0 ; index < length; index++) {
1017     initialize_immediate_oop(&dest[index], array->at(index));
1018   }
1019 
1020   // Now we can fix up all the oops in the code.  We need to do this
1021   // in the code because the assembler uses jobjects as placeholders.
1022   // The code and relocations have already been initialized by the
1023   // CodeBlob constructor, so it is valid even at this early point to
1024   // iterate over relocations and patch the code.
1025   fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
1026 }
1027 
1028 void nmethod::copy_values(GrowableArray<Metadata*>* array) {
1029   int length = array->length();
1030   assert((address)(metadata_begin() + length) <= (address)metadata_end(), "big enough");
1031   Metadata** dest = metadata_begin();
1032   for (int index = 0 ; index < length; index++) {
1033     dest[index] = array->at(index);
1034   }
1035 }
1036 
1037 void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
1038   // re-patch all oop-bearing instructions, just in case some oops moved
1039   RelocIterator iter(this, begin, end);
1040   while (iter.next()) {
1041     if (iter.type() == relocInfo::oop_type) {
1042       oop_Relocation* reloc = iter.oop_reloc();
1043       if (initialize_immediates && reloc->oop_is_immediate()) {
1044         oop* dest = reloc->oop_addr();
1045         initialize_immediate_oop(dest, (jobject) *dest);
1046       }
1047       // Refresh the oop-related bits of this instruction.
1048       reloc->fix_oop_relocation();
1049     } else if (iter.type() == relocInfo::metadata_type) {
1050       metadata_Relocation* reloc = iter.metadata_reloc();
1051       reloc->fix_metadata_relocation();
1052     }
1053   }
1054 }
1055 
1056 
1057 void nmethod::verify_clean_inline_caches() {
1058   assert(CompiledICLocker::is_safe(this), "mt unsafe call");
1059 
1060   ResourceMark rm;
1061   RelocIterator iter(this, oops_reloc_begin());
1062   while(iter.next()) {
1063     switch(iter.type()) {
1064       case relocInfo::virtual_call_type:
1065       case relocInfo::opt_virtual_call_type: {
1066         CompiledIC *ic = CompiledIC_at(&iter);
1067         // Ok, to lookup references to zombies here
1068         CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
1069         assert(cb != NULL, "destination not in CodeBlob?");
1070         nmethod* nm = cb->as_nmethod_or_null();
1071         if( nm != NULL ) {
1072           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
1073           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
1074             assert(ic->is_clean(), "IC should be clean");
1075           }
1076         }
1077         break;
1078       }
1079       case relocInfo::static_call_type: {
1080         CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
1081         CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
1082         assert(cb != NULL, "destination not in CodeBlob?");
1083         nmethod* nm = cb->as_nmethod_or_null();
1084         if( nm != NULL ) {
1085           // Verify that inline caches pointing to both zombie and not_entrant methods are clean
1086           if (!nm->is_in_use() || (nm->method()->code() != nm)) {
1087             assert(csc->is_clean(), "IC should be clean");
1088           }
1089         }
1090         break;
1091       }
1092       default:
1093         break;
1094     }
1095   }
1096 }
1097 
1098 // This is a private interface with the sweeper.
1099 void nmethod::mark_as_seen_on_stack() {
1100   assert(is_alive(), "Must be an alive method");
1101   // Set the traversal mark to ensure that the sweeper does 2
1102   // cleaning passes before moving to zombie.
1103   set_stack_traversal_mark(NMethodSweeper::traversal_count());
1104 }
1105 
1106 // Tell if a non-entrant method can be converted to a zombie (i.e.,
1107 // there are no activations on the stack, not in use by the VM,
1108 // and not in use by the ServiceThread)
1109 bool nmethod::can_convert_to_zombie() {
1110   // Note that this is called when the sweeper has observed the nmethod to be
1111   // not_entrant. However, with concurrent code cache unloading, the state
1112   // might have moved on to unloaded if it is_unloading(), due to racing
1113   // concurrent GC threads.
1114   assert(is_not_entrant() || is_unloading(), "must be a non-entrant method");
1115 
1116   // Since the nmethod sweeper only does partial sweep the sweeper's traversal
1117   // count can be greater than the stack traversal count before it hits the
1118   // nmethod for the second time.
1119   // If an is_unloading() nmethod is still not_entrant, then it is not safe to
1120   // convert it to zombie due to GC unloading interactions. However, if it
1121   // has become unloaded, then it is okay to convert such nmethods to zombie.
1122   return stack_traversal_mark() + 1 < NMethodSweeper::traversal_count() &&
1123          !is_locked_by_vm() && (!is_unloading() || is_unloaded());
1124 }
1125 
1126 void nmethod::inc_decompile_count() {
1127   if (!is_compiled_by_c2() && !is_compiled_by_jvmci()) return;
1128   // Could be gated by ProfileTraps, but do not bother...
1129   Method* m = method();
1130   if (m == NULL)  return;
1131   MethodData* mdo = m->method_data();
1132   if (mdo == NULL)  return;
1133   // There is a benign race here.  See comments in methodData.hpp.
1134   mdo->inc_decompile_count();
1135 }
1136 
1137 void nmethod::make_unloaded() {
1138   post_compiled_method_unload();
1139 
1140   // This nmethod is being unloaded, make sure that dependencies
1141   // recorded in instanceKlasses get flushed.
1142   // Since this work is being done during a GC, defer deleting dependencies from the
1143   // InstanceKlass.
1144   assert(Universe::heap()->is_gc_active() || Thread::current()->is_ConcurrentGC_thread(),
1145          "should only be called during gc");
1146   flush_dependencies(/*delete_immediately*/false);
1147 
1148   // Break cycle between nmethod & method
1149   LogTarget(Trace, class, unload, nmethod) lt;
1150   if (lt.is_enabled()) {
1151     LogStream ls(lt);
1152     ls.print("making nmethod " INTPTR_FORMAT
1153              " unloadable, Method*(" INTPTR_FORMAT
1154              ") ",
1155              p2i(this), p2i(_method));
1156      ls.cr();
1157   }
1158   // Unlink the osr method, so we do not look this up again
1159   if (is_osr_method()) {
1160     // Invalidate the osr nmethod only once
1161     if (is_in_use()) {
1162       invalidate_osr_method();
1163     }
1164 #ifdef ASSERT
1165     if (method() != NULL) {
1166       // Make sure osr nmethod is invalidated, i.e. not on the list
1167       bool found = method()->method_holder()->remove_osr_nmethod(this);
1168       assert(!found, "osr nmethod should have been invalidated");
1169     }
1170 #endif
1171   }
1172 
1173   // If _method is already NULL the Method* is about to be unloaded,
1174   // so we don't have to break the cycle. Note that it is possible to
1175   // have the Method* live here, in case we unload the nmethod because
1176   // it is pointing to some oop (other than the Method*) being unloaded.
1177   if (_method != NULL) {
1178     // OSR methods point to the Method*, but the Method* does not
1179     // point back!
1180     if (_method->code() == this) {
1181       _method->clear_code(); // Break a cycle
1182     }
1183   }
1184 
1185   // Make the class unloaded - i.e., change state and notify sweeper
1186   assert(SafepointSynchronize::is_at_safepoint() || Thread::current()->is_ConcurrentGC_thread(),
1187          "must be at safepoint");
1188 
1189   {
1190     // Clear ICStubs and release any CompiledICHolders.
1191     CompiledICLocker ml(this);
1192     clear_ic_callsites();
1193   }
1194 
1195   // Unregister must be done before the state change
1196   {
1197     MutexLocker ml(SafepointSynchronize::is_at_safepoint() ? NULL : CodeCache_lock,
1198                      Mutex::_no_safepoint_check_flag);
1199     Universe::heap()->unregister_nmethod(this);
1200     CodeCache::unregister_old_nmethod(this);
1201   }
1202 
1203   // Clear the method of this dead nmethod
1204   set_method(NULL);
1205 
1206   // Log the unloading.
1207   log_state_change();
1208 
1209   // The Method* is gone at this point
1210   assert(_method == NULL, "Tautology");
1211 
1212   set_osr_link(NULL);
1213   NMethodSweeper::report_state_change(this);
1214 
1215   // The release is only needed for compile-time ordering, as accesses
1216   // into the nmethod after the store are not safe due to the sweeper
1217   // being allowed to free it when the store is observed, during
1218   // concurrent nmethod unloading. Therefore, there is no need for
1219   // acquire on the loader side.
1220   OrderAccess::release_store(&_state, (signed char)unloaded);
1221 
1222 #if INCLUDE_JVMCI
1223   // Clear the link between this nmethod and a HotSpotNmethod mirror
1224   JVMCINMethodData* nmethod_data = jvmci_nmethod_data();
1225   if (nmethod_data != NULL) {
1226     nmethod_data->invalidate_nmethod_mirror(this);
1227     nmethod_data->clear_nmethod_mirror(this);
1228   }
1229 #endif
1230 }
1231 
1232 void nmethod::invalidate_osr_method() {
1233   assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
1234   // Remove from list of active nmethods
1235   if (method() != NULL) {
1236     method()->method_holder()->remove_osr_nmethod(this);
1237   }
1238 }
1239 
1240 void nmethod::log_state_change() const {
1241   if (LogCompilation) {
1242     if (xtty != NULL) {
1243       ttyLocker ttyl;  // keep the following output all in one block
1244       if (_state == unloaded) {
1245         xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
1246                          os::current_thread_id());
1247       } else {
1248         xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
1249                          os::current_thread_id(),
1250                          (_state == zombie ? " zombie='1'" : ""));
1251       }
1252       log_identity(xtty);
1253       xtty->stamp();
1254       xtty->end_elem();
1255     }
1256   }
1257 
1258   const char *state_msg = _state == zombie ? "made zombie" : "made not entrant";
1259   CompileTask::print_ul(this, state_msg);
1260   if (PrintCompilation && _state != unloaded) {
1261     print_on(tty, state_msg);
1262   }
1263 }
1264 
1265 void nmethod::unlink_from_method(bool acquire_lock) {
1266   // We need to check if both the _code and _from_compiled_code_entry_point
1267   // refer to this nmethod because there is a race in setting these two fields
1268   // in Method* as seen in bugid 4947125.
1269   // If the vep() points to the zombie nmethod, the memory for the nmethod
1270   // could be flushed and the compiler and vtable stubs could still call
1271   // through it.
1272   if (method() != NULL && (method()->code() == this ||
1273                            method()->from_compiled_entry() == verified_entry_point())) {
1274     method()->clear_code(acquire_lock);
1275   }
1276 }
1277 
1278 /**
1279  * Common functionality for both make_not_entrant and make_zombie
1280  */
1281 bool nmethod::make_not_entrant_or_zombie(int state) {
1282   assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
1283   assert(!is_zombie(), "should not already be a zombie");
1284 
1285   if (_state == state) {
1286     // Avoid taking the lock if already in required state.
1287     // This is safe from races because the state is an end-state,
1288     // which the nmethod cannot back out of once entered.
1289     // No need for fencing either.
1290     return false;
1291   }
1292 
1293   // Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
1294   nmethodLocker nml(this);
1295   methodHandle the_method(method());
1296   // This can be called while the system is already at a safepoint which is ok
1297   NoSafepointVerifier nsv(true, !SafepointSynchronize::is_at_safepoint());
1298 
1299   // during patching, depending on the nmethod state we must notify the GC that
1300   // code has been unloaded, unregistering it. We cannot do this right while
1301   // holding the Patching_lock because we need to use the CodeCache_lock. This
1302   // would be prone to deadlocks.
1303   // This flag is used to remember whether we need to later lock and unregister.
1304   bool nmethod_needs_unregister = false;
1305 
1306   {
1307     // invalidate osr nmethod before acquiring the patching lock since
1308     // they both acquire leaf locks and we don't want a deadlock.
1309     // This logic is equivalent to the logic below for patching the
1310     // verified entry point of regular methods. We check that the
1311     // nmethod is in use to ensure that it is invalidated only once.
1312     if (is_osr_method() && is_in_use()) {
1313       // this effectively makes the osr nmethod not entrant
1314       invalidate_osr_method();
1315     }
1316 
1317     // Enter critical section.  Does not block for safepoint.
1318     MutexLocker pl(Patching_lock, Mutex::_no_safepoint_check_flag);
1319 
1320     if (_state == state) {
1321       // another thread already performed this transition so nothing
1322       // to do, but return false to indicate this.
1323       return false;
1324     }
1325 
1326     // The caller can be calling the method statically or through an inline
1327     // cache call.
1328     if (!is_osr_method() && !is_not_entrant()) {
1329       NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
1330                   SharedRuntime::get_handle_wrong_method_stub());
1331     }
1332 
1333     if (is_in_use() && update_recompile_counts()) {
1334       // It's a true state change, so mark the method as decompiled.
1335       // Do it only for transition from alive.
1336       inc_decompile_count();
1337     }
1338 
1339     // If the state is becoming a zombie, signal to unregister the nmethod with
1340     // the heap.
1341     // This nmethod may have already been unloaded during a full GC.
1342     if ((state == zombie) && !is_unloaded()) {
1343       nmethod_needs_unregister = true;
1344     }
1345 
1346     // Must happen before state change. Otherwise we have a race condition in
1347     // nmethod::can_not_entrant_be_converted(). I.e., a method can immediately
1348     // transition its state from 'not_entrant' to 'zombie' without having to wait
1349     // for stack scanning.
1350     if (state == not_entrant) {
1351       mark_as_seen_on_stack();
1352       OrderAccess::storestore(); // _stack_traversal_mark and _state
1353     }
1354 
1355     // Change state
1356     _state = state;
1357 
1358     // Log the transition once
1359     log_state_change();
1360 
1361     // Remove nmethod from method.
1362     unlink_from_method(false /* already owns Patching_lock */);
1363   } // leave critical region under Patching_lock
1364 
1365 #if INCLUDE_JVMCI
1366   // Invalidate can't occur while holding the Patching lock
1367   JVMCINMethodData* nmethod_data = jvmci_nmethod_data();
1368   if (nmethod_data != NULL) {
1369     nmethod_data->invalidate_nmethod_mirror(this);
1370   }
1371 #endif
1372 
1373 #ifdef ASSERT
1374   if (is_osr_method() && method() != NULL) {
1375     // Make sure osr nmethod is invalidated, i.e. not on the list
1376     bool found = method()->method_holder()->remove_osr_nmethod(this);
1377     assert(!found, "osr nmethod should have been invalidated");
1378   }
1379 #endif
1380 
1381   // When the nmethod becomes zombie it is no longer alive so the
1382   // dependencies must be flushed.  nmethods in the not_entrant
1383   // state will be flushed later when the transition to zombie
1384   // happens or they get unloaded.
1385   if (state == zombie) {
1386     {
1387       // Flushing dependencies must be done before any possible
1388       // safepoint can sneak in, otherwise the oops used by the
1389       // dependency logic could have become stale.
1390       MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1391       if (nmethod_needs_unregister) {
1392         Universe::heap()->unregister_nmethod(this);
1393         CodeCache::unregister_old_nmethod(this);
1394       }
1395       flush_dependencies(/*delete_immediately*/true);
1396     }
1397 
1398 #if INCLUDE_JVMCI
1399     // Now that the nmethod has been unregistered, it's
1400     // safe to clear the HotSpotNmethod mirror oop.
1401     if (nmethod_data != NULL) {
1402       nmethod_data->clear_nmethod_mirror(this);
1403     }
1404 #endif
1405 
1406     // Clear ICStubs to prevent back patching stubs of zombie or flushed
1407     // nmethods during the next safepoint (see ICStub::finalize), as well
1408     // as to free up CompiledICHolder resources.
1409     {
1410       CompiledICLocker ml(this);
1411       clear_ic_callsites();
1412     }
1413 
1414     // zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
1415     // event and it hasn't already been reported for this nmethod then
1416     // report it now. The event may have been reported earlier if the GC
1417     // marked it for unloading). JvmtiDeferredEventQueue support means
1418     // we no longer go to a safepoint here.
1419     post_compiled_method_unload();
1420 
1421 #ifdef ASSERT
1422     // It's no longer safe to access the oops section since zombie
1423     // nmethods aren't scanned for GC.
1424     _oops_are_stale = true;
1425 #endif
1426      // the Method may be reclaimed by class unloading now that the
1427      // nmethod is in zombie state
1428     set_method(NULL);
1429   } else {
1430     assert(state == not_entrant, "other cases may need to be handled differently");
1431   }
1432 
1433   if (TraceCreateZombies && state == zombie) {
1434     ResourceMark m;
1435     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");
1436   }
1437 
1438   NMethodSweeper::report_state_change(this);
1439   return true;
1440 }
1441 
1442 void nmethod::flush() {
1443   MutexLocker mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
1444   // Note that there are no valid oops in the nmethod anymore.
1445   assert(!is_osr_method() || is_unloaded() || is_zombie(),
1446          "osr nmethod must be unloaded or zombie before flushing");
1447   assert(is_zombie() || is_osr_method(), "must be a zombie method");
1448   assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
1449   assert_locked_or_safepoint(CodeCache_lock);
1450 
1451   // completely deallocate this method
1452   Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, p2i(this));
1453   if (PrintMethodFlushing) {
1454     tty->print_cr("*flushing %s nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT
1455                   "/Free CodeCache:" SIZE_FORMAT "Kb",
1456                   is_osr_method() ? "osr" : "",_compile_id, p2i(this), CodeCache::blob_count(),
1457                   CodeCache::unallocated_capacity(CodeCache::get_code_blob_type(this))/1024);
1458   }
1459 
1460   // We need to deallocate any ExceptionCache data.
1461   // Note that we do not need to grab the nmethod lock for this, it
1462   // better be thread safe if we're disposing of it!
1463   ExceptionCache* ec = exception_cache();
1464   set_exception_cache(NULL);
1465   while(ec != NULL) {
1466     ExceptionCache* next = ec->next();
1467     delete ec;
1468     ec = next;
1469   }
1470 
1471   Universe::heap()->flush_nmethod(this);
1472 
1473   CodeBlob::flush();
1474   CodeCache::free(this);
1475 }
1476 
1477 oop nmethod::oop_at(int index) const {
1478   if (index == 0) {
1479     return NULL;
1480   }
1481   return NativeAccess<AS_NO_KEEPALIVE>::oop_load(oop_addr_at(index));
1482 }
1483 
1484 //
1485 // Notify all classes this nmethod is dependent on that it is no
1486 // longer dependent. This should only be called in two situations.
1487 // First, when a nmethod transitions to a zombie all dependents need
1488 // to be clear.  Since zombification happens at a safepoint there's no
1489 // synchronization issues.  The second place is a little more tricky.
1490 // During phase 1 of mark sweep class unloading may happen and as a
1491 // result some nmethods may get unloaded.  In this case the flushing
1492 // of dependencies must happen during phase 1 since after GC any
1493 // dependencies in the unloaded nmethod won't be updated, so
1494 // traversing the dependency information in unsafe.  In that case this
1495 // function is called with a boolean argument and this function only
1496 // notifies instanceKlasses that are reachable
1497 
1498 void nmethod::flush_dependencies(bool delete_immediately) {
1499   DEBUG_ONLY(bool called_by_gc = Universe::heap()->is_gc_active() || Thread::current()->is_ConcurrentGC_thread();)
1500   assert(called_by_gc != delete_immediately,
1501   "delete_immediately is false if and only if we are called during GC");
1502   if (!has_flushed_dependencies()) {
1503     set_has_flushed_dependencies();
1504     for (Dependencies::DepStream deps(this); deps.next(); ) {
1505       if (deps.type() == Dependencies::call_site_target_value) {
1506         // CallSite dependencies are managed on per-CallSite instance basis.
1507         oop call_site = deps.argument_oop(0);
1508         if (delete_immediately) {
1509           assert_locked_or_safepoint(CodeCache_lock);
1510           MethodHandles::remove_dependent_nmethod(call_site, this);
1511         } else {
1512           MethodHandles::clean_dependency_context(call_site);
1513         }
1514       } else {
1515         Klass* klass = deps.context_type();
1516         if (klass == NULL) {
1517           continue;  // ignore things like evol_method
1518         }
1519         // During GC delete_immediately is false, and liveness
1520         // of dependee determines class that needs to be updated.
1521         if (delete_immediately) {
1522           assert_locked_or_safepoint(CodeCache_lock);
1523           InstanceKlass::cast(klass)->remove_dependent_nmethod(this);
1524         } else if (klass->is_loader_alive()) {
1525           // The GC may clean dependency contexts concurrently and in parallel.
1526           InstanceKlass::cast(klass)->clean_dependency_context();
1527         }
1528       }
1529     }
1530   }
1531 }
1532 
1533 // ------------------------------------------------------------------
1534 // post_compiled_method_load_event
1535 // new method for install_code() path
1536 // Transfer information from compilation to jvmti
1537 void nmethod::post_compiled_method_load_event() {
1538 
1539   Method* moop = method();
1540   HOTSPOT_COMPILED_METHOD_LOAD(
1541       (char *) moop->klass_name()->bytes(),
1542       moop->klass_name()->utf8_length(),
1543       (char *) moop->name()->bytes(),
1544       moop->name()->utf8_length(),
1545       (char *) moop->signature()->bytes(),
1546       moop->signature()->utf8_length(),
1547       insts_begin(), insts_size());
1548 
1549   if (JvmtiExport::should_post_compiled_method_load() ||
1550       JvmtiExport::should_post_compiled_method_unload()) {
1551     get_and_cache_jmethod_id();
1552   }
1553 
1554   if (JvmtiExport::should_post_compiled_method_load()) {
1555     // Let the Service thread (which is a real Java thread) post the event
1556     MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
1557     JvmtiDeferredEventQueue::enqueue(
1558       JvmtiDeferredEvent::compiled_method_load_event(this));
1559   }
1560 }
1561 
1562 jmethodID nmethod::get_and_cache_jmethod_id() {
1563   if (_jmethod_id == NULL) {
1564     // Cache the jmethod_id since it can no longer be looked up once the
1565     // method itself has been marked for unloading.
1566     _jmethod_id = method()->jmethod_id();
1567   }
1568   return _jmethod_id;
1569 }
1570 
1571 void nmethod::post_compiled_method_unload() {
1572   if (unload_reported()) {
1573     // During unloading we transition to unloaded and then to zombie
1574     // and the unloading is reported during the first transition.
1575     return;
1576   }
1577 
1578   assert(_method != NULL && !is_unloaded(), "just checking");
1579   DTRACE_METHOD_UNLOAD_PROBE(method());
1580 
1581   // If a JVMTI agent has enabled the CompiledMethodUnload event then
1582   // post the event. Sometime later this nmethod will be made a zombie
1583   // by the sweeper but the Method* will not be valid at that point.
1584   // If the _jmethod_id is null then no load event was ever requested
1585   // so don't bother posting the unload.  The main reason for this is
1586   // that the jmethodID is a weak reference to the Method* so if
1587   // it's being unloaded there's no way to look it up since the weak
1588   // ref will have been cleared.
1589   if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
1590     assert(!unload_reported(), "already unloaded");
1591     JvmtiDeferredEvent event =
1592       JvmtiDeferredEvent::compiled_method_unload_event(this,
1593           _jmethod_id, insts_begin());
1594     MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
1595     JvmtiDeferredEventQueue::enqueue(event);
1596   }
1597 
1598   // The JVMTI CompiledMethodUnload event can be enabled or disabled at
1599   // any time. As the nmethod is being unloaded now we mark it has
1600   // having the unload event reported - this will ensure that we don't
1601   // attempt to report the event in the unlikely scenario where the
1602   // event is enabled at the time the nmethod is made a zombie.
1603   set_unload_reported();
1604 }
1605 
1606 // Iterate over metadata calling this function.   Used by RedefineClasses
1607 void nmethod::metadata_do(MetadataClosure* f) {
1608   {
1609     // Visit all immediate references that are embedded in the instruction stream.
1610     RelocIterator iter(this, oops_reloc_begin());
1611     while (iter.next()) {
1612       if (iter.type() == relocInfo::metadata_type ) {
1613         metadata_Relocation* r = iter.metadata_reloc();
1614         // In this metadata, we must only follow those metadatas directly embedded in
1615         // the code.  Other metadatas (oop_index>0) are seen as part of
1616         // the metadata section below.
1617         assert(1 == (r->metadata_is_immediate()) +
1618                (r->metadata_addr() >= metadata_begin() && r->metadata_addr() < metadata_end()),
1619                "metadata must be found in exactly one place");
1620         if (r->metadata_is_immediate() && r->metadata_value() != NULL) {
1621           Metadata* md = r->metadata_value();
1622           if (md != _method) f->do_metadata(md);
1623         }
1624       } else if (iter.type() == relocInfo::virtual_call_type) {
1625         // Check compiledIC holders associated with this nmethod
1626         ResourceMark rm;
1627         CompiledIC *ic = CompiledIC_at(&iter);
1628         if (ic->is_icholder_call()) {
1629           CompiledICHolder* cichk = ic->cached_icholder();
1630           f->do_metadata(cichk->holder_metadata());
1631           f->do_metadata(cichk->holder_klass());
1632         } else {
1633           Metadata* ic_oop = ic->cached_metadata();
1634           if (ic_oop != NULL) {
1635             f->do_metadata(ic_oop);
1636           }
1637         }
1638       }
1639     }
1640   }
1641 
1642   // Visit the metadata section
1643   for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
1644     if (*p == Universe::non_oop_word() || *p == NULL)  continue;  // skip non-oops
1645     Metadata* md = *p;
1646     f->do_metadata(md);
1647   }
1648 
1649   // Visit metadata not embedded in the other places.
1650   if (_method != NULL) f->do_metadata(_method);
1651 }
1652 
1653 // The _is_unloading_state encodes a tuple comprising the unloading cycle
1654 // and the result of IsUnloadingBehaviour::is_unloading() fpr that cycle.
1655 // This is the bit layout of the _is_unloading_state byte: 00000CCU
1656 // CC refers to the cycle, which has 2 bits, and U refers to the result of
1657 // IsUnloadingBehaviour::is_unloading() for that unloading cycle.
1658 
1659 class IsUnloadingState: public AllStatic {
1660   static const uint8_t _is_unloading_mask = 1;
1661   static const uint8_t _is_unloading_shift = 0;
1662   static const uint8_t _unloading_cycle_mask = 6;
1663   static const uint8_t _unloading_cycle_shift = 1;
1664 
1665   static uint8_t set_is_unloading(uint8_t state, bool value) {
1666     state &= ~_is_unloading_mask;
1667     if (value) {
1668       state |= 1 << _is_unloading_shift;
1669     }
1670     assert(is_unloading(state) == value, "unexpected unloading cycle overflow");
1671     return state;
1672   }
1673 
1674   static uint8_t set_unloading_cycle(uint8_t state, uint8_t value) {
1675     state &= ~_unloading_cycle_mask;
1676     state |= value << _unloading_cycle_shift;
1677     assert(unloading_cycle(state) == value, "unexpected unloading cycle overflow");
1678     return state;
1679   }
1680 
1681 public:
1682   static bool is_unloading(uint8_t state) { return (state & _is_unloading_mask) >> _is_unloading_shift == 1; }
1683   static uint8_t unloading_cycle(uint8_t state) { return (state & _unloading_cycle_mask) >> _unloading_cycle_shift; }
1684 
1685   static uint8_t create(bool is_unloading, uint8_t unloading_cycle) {
1686     uint8_t state = 0;
1687     state = set_is_unloading(state, is_unloading);
1688     state = set_unloading_cycle(state, unloading_cycle);
1689     return state;
1690   }
1691 };
1692 
1693 bool nmethod::is_unloading() {
1694   uint8_t state = RawAccess<MO_RELAXED>::load(&_is_unloading_state);
1695   bool state_is_unloading = IsUnloadingState::is_unloading(state);
1696   uint8_t state_unloading_cycle = IsUnloadingState::unloading_cycle(state);
1697   if (state_is_unloading) {
1698     return true;
1699   }
1700   uint8_t current_cycle = CodeCache::unloading_cycle();
1701   if (state_unloading_cycle == current_cycle) {
1702     return false;
1703   }
1704 
1705   // The IsUnloadingBehaviour is responsible for checking if there are any dead
1706   // oops in the CompiledMethod, by calling oops_do on it.
1707   state_unloading_cycle = current_cycle;
1708 
1709   if (is_zombie()) {
1710     // Zombies without calculated unloading epoch are never unloading due to GC.
1711 
1712     // There are no races where a previously observed is_unloading() nmethod
1713     // suddenly becomes not is_unloading() due to here being observed as zombie.
1714 
1715     // With STW unloading, all is_alive() && is_unloading() nmethods are unlinked
1716     // and unloaded in the safepoint. That makes races where an nmethod is first
1717     // observed as is_alive() && is_unloading() and subsequently observed as
1718     // is_zombie() impossible.
1719 
1720     // With concurrent unloading, all references to is_unloading() nmethods are
1721     // first unlinked (e.g. IC caches and dependency contexts). Then a global
1722     // handshake operation is performed with all JavaThreads before finally
1723     // unloading the nmethods. The sweeper never converts is_alive() && is_unloading()
1724     // nmethods to zombies; it waits for them to become is_unloaded(). So before
1725     // the global handshake, it is impossible for is_unloading() nmethods to
1726     // racingly become is_zombie(). And is_unloading() is calculated for all is_alive()
1727     // nmethods before taking that global handshake, meaning that it will never
1728     // be recalculated after the handshake.
1729 
1730     // After that global handshake, is_unloading() nmethods are only observable
1731     // to the iterators, and they will never trigger recomputation of the cached
1732     // is_unloading_state, and hence may not suffer from such races.
1733 
1734     state_is_unloading = false;
1735   } else {
1736     state_is_unloading = IsUnloadingBehaviour::current()->is_unloading(this);
1737   }
1738 
1739   state = IsUnloadingState::create(state_is_unloading, state_unloading_cycle);
1740 
1741   RawAccess<MO_RELAXED>::store(&_is_unloading_state, state);
1742 
1743   return state_is_unloading;
1744 }
1745 
1746 void nmethod::clear_unloading_state() {
1747   uint8_t state = IsUnloadingState::create(false, CodeCache::unloading_cycle());
1748   RawAccess<MO_RELAXED>::store(&_is_unloading_state, state);
1749 }
1750 
1751 
1752 // This is called at the end of the strong tracing/marking phase of a
1753 // GC to unload an nmethod if it contains otherwise unreachable
1754 // oops.
1755 
1756 void nmethod::do_unloading(bool unloading_occurred) {
1757   // Make sure the oop's ready to receive visitors
1758   assert(!is_zombie() && !is_unloaded(),
1759          "should not call follow on zombie or unloaded nmethod");
1760 
1761   if (is_unloading()) {
1762     make_unloaded();
1763   } else {
1764     guarantee(unload_nmethod_caches(unloading_occurred),
1765               "Should not need transition stubs");
1766   }
1767 }
1768 
1769 void nmethod::oops_do(OopClosure* f, bool allow_zombie) {
1770   // make sure the oops ready to receive visitors
1771   assert(allow_zombie || !is_zombie(), "should not call follow on zombie nmethod");
1772   assert(!is_unloaded(), "should not call follow on unloaded nmethod");
1773 
1774   // Prevent extra code cache walk for platforms that don't have immediate oops.
1775   if (relocInfo::mustIterateImmediateOopsInCode()) {
1776     RelocIterator iter(this, oops_reloc_begin());
1777 
1778     while (iter.next()) {
1779       if (iter.type() == relocInfo::oop_type ) {
1780         oop_Relocation* r = iter.oop_reloc();
1781         // In this loop, we must only follow those oops directly embedded in
1782         // the code.  Other oops (oop_index>0) are seen as part of scopes_oops.
1783         assert(1 == (r->oop_is_immediate()) +
1784                (r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
1785                "oop must be found in exactly one place");
1786         if (r->oop_is_immediate() && r->oop_value() != NULL) {
1787           f->do_oop(r->oop_addr());
1788         }
1789       }
1790     }
1791   }
1792 
1793   // Scopes
1794   // This includes oop constants not inlined in the code stream.
1795   for (oop* p = oops_begin(); p < oops_end(); p++) {
1796     if (*p == Universe::non_oop_word())  continue;  // skip non-oops
1797     f->do_oop(p);
1798   }
1799 }
1800 
1801 #define NMETHOD_SENTINEL ((nmethod*)badAddress)
1802 
1803 nmethod* volatile nmethod::_oops_do_mark_nmethods;
1804 
1805 // An nmethod is "marked" if its _mark_link is set non-null.
1806 // Even if it is the end of the linked list, it will have a non-null link value,
1807 // as long as it is on the list.
1808 // This code must be MP safe, because it is used from parallel GC passes.
1809 bool nmethod::test_set_oops_do_mark() {
1810   assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
1811   if (_oops_do_mark_link == NULL) {
1812     // Claim this nmethod for this thread to mark.
1813     if (Atomic::replace_if_null(NMETHOD_SENTINEL, &_oops_do_mark_link)) {
1814       // Atomically append this nmethod (now claimed) to the head of the list:
1815       nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
1816       for (;;) {
1817         nmethod* required_mark_nmethods = observed_mark_nmethods;
1818         _oops_do_mark_link = required_mark_nmethods;
1819         observed_mark_nmethods =
1820           Atomic::cmpxchg(this, &_oops_do_mark_nmethods, required_mark_nmethods);
1821         if (observed_mark_nmethods == required_mark_nmethods)
1822           break;
1823       }
1824       // Mark was clear when we first saw this guy.
1825       LogTarget(Trace, gc, nmethod) lt;
1826       if (lt.is_enabled()) {
1827         LogStream ls(lt);
1828         CompileTask::print(&ls, this, "oops_do, mark", /*short_form:*/ true);
1829       }
1830       return false;
1831     }
1832   }
1833   // On fall through, another racing thread marked this nmethod before we did.
1834   return true;
1835 }
1836 
1837 void nmethod::oops_do_marking_prologue() {
1838   log_trace(gc, nmethod)("oops_do_marking_prologue");
1839   assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
1840   // We use cmpxchg instead of regular assignment here because the user
1841   // may fork a bunch of threads, and we need them all to see the same state.
1842   nmethod* observed = Atomic::cmpxchg(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, (nmethod*)NULL);
1843   guarantee(observed == NULL, "no races in this sequential code");
1844 }
1845 
1846 void nmethod::oops_do_marking_epilogue() {
1847   assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
1848   nmethod* cur = _oops_do_mark_nmethods;
1849   while (cur != NMETHOD_SENTINEL) {
1850     assert(cur != NULL, "not NULL-terminated");
1851     nmethod* next = cur->_oops_do_mark_link;
1852     cur->_oops_do_mark_link = NULL;
1853     DEBUG_ONLY(cur->verify_oop_relocations());
1854 
1855     LogTarget(Trace, gc, nmethod) lt;
1856     if (lt.is_enabled()) {
1857       LogStream ls(lt);
1858       CompileTask::print(&ls, cur, "oops_do, unmark", /*short_form:*/ true);
1859     }
1860     cur = next;
1861   }
1862   nmethod* required = _oops_do_mark_nmethods;
1863   nmethod* observed = Atomic::cmpxchg((nmethod*)NULL, &_oops_do_mark_nmethods, required);
1864   guarantee(observed == required, "no races in this sequential code");
1865   log_trace(gc, nmethod)("oops_do_marking_epilogue");
1866 }
1867 
1868 inline bool includes(void* p, void* from, void* to) {
1869   return from <= p && p < to;
1870 }
1871 
1872 
1873 void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
1874   assert(count >= 2, "must be sentinel values, at least");
1875 
1876 #ifdef ASSERT
1877   // must be sorted and unique; we do a binary search in find_pc_desc()
1878   int prev_offset = pcs[0].pc_offset();
1879   assert(prev_offset == PcDesc::lower_offset_limit,
1880          "must start with a sentinel");
1881   for (int i = 1; i < count; i++) {
1882     int this_offset = pcs[i].pc_offset();
1883     assert(this_offset > prev_offset, "offsets must be sorted");
1884     prev_offset = this_offset;
1885   }
1886   assert(prev_offset == PcDesc::upper_offset_limit,
1887          "must end with a sentinel");
1888 #endif //ASSERT
1889 
1890   // Search for MethodHandle invokes and tag the nmethod.
1891   for (int i = 0; i < count; i++) {
1892     if (pcs[i].is_method_handle_invoke()) {
1893       set_has_method_handle_invokes(true);
1894       break;
1895     }
1896   }
1897   assert(has_method_handle_invokes() == (_deopt_mh_handler_begin != NULL), "must have deopt mh handler");
1898 
1899   int size = count * sizeof(PcDesc);
1900   assert(scopes_pcs_size() >= size, "oob");
1901   memcpy(scopes_pcs_begin(), pcs, size);
1902 
1903   // Adjust the final sentinel downward.
1904   PcDesc* last_pc = &scopes_pcs_begin()[count-1];
1905   assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
1906   last_pc->set_pc_offset(content_size() + 1);
1907   for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
1908     // Fill any rounding gaps with copies of the last record.
1909     last_pc[1] = last_pc[0];
1910   }
1911   // The following assert could fail if sizeof(PcDesc) is not
1912   // an integral multiple of oopSize (the rounding term).
1913   // If it fails, change the logic to always allocate a multiple
1914   // of sizeof(PcDesc), and fill unused words with copies of *last_pc.
1915   assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
1916 }
1917 
1918 void nmethod::copy_scopes_data(u_char* buffer, int size) {
1919   assert(scopes_data_size() >= size, "oob");
1920   memcpy(scopes_data_begin(), buffer, size);
1921 }
1922 
1923 #ifdef ASSERT
1924 static PcDesc* linear_search(const PcDescSearch& search, int pc_offset, bool approximate) {
1925   PcDesc* lower = search.scopes_pcs_begin();
1926   PcDesc* upper = search.scopes_pcs_end();
1927   lower += 1; // exclude initial sentinel
1928   PcDesc* res = NULL;
1929   for (PcDesc* p = lower; p < upper; p++) {
1930     NOT_PRODUCT(--pc_nmethod_stats.pc_desc_tests);  // don't count this call to match_desc
1931     if (match_desc(p, pc_offset, approximate)) {
1932       if (res == NULL)
1933         res = p;
1934       else
1935         res = (PcDesc*) badAddress;
1936     }
1937   }
1938   return res;
1939 }
1940 #endif
1941 
1942 
1943 // Finds a PcDesc with real-pc equal to "pc"
1944 PcDesc* PcDescContainer::find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search) {
1945   address base_address = search.code_begin();
1946   if ((pc < base_address) ||
1947       (pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
1948     return NULL;  // PC is wildly out of range
1949   }
1950   int pc_offset = (int) (pc - base_address);
1951 
1952   // Check the PcDesc cache if it contains the desired PcDesc
1953   // (This as an almost 100% hit rate.)
1954   PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
1955   if (res != NULL) {
1956     assert(res == linear_search(search, pc_offset, approximate), "cache ok");
1957     return res;
1958   }
1959 
1960   // Fallback algorithm: quasi-linear search for the PcDesc
1961   // Find the last pc_offset less than the given offset.
1962   // The successor must be the required match, if there is a match at all.
1963   // (Use a fixed radix to avoid expensive affine pointer arithmetic.)
1964   PcDesc* lower = search.scopes_pcs_begin();
1965   PcDesc* upper = search.scopes_pcs_end();
1966   upper -= 1; // exclude final sentinel
1967   if (lower >= upper)  return NULL;  // native method; no PcDescs at all
1968 
1969 #define assert_LU_OK \
1970   /* invariant on lower..upper during the following search: */ \
1971   assert(lower->pc_offset() <  pc_offset, "sanity"); \
1972   assert(upper->pc_offset() >= pc_offset, "sanity")
1973   assert_LU_OK;
1974 
1975   // Use the last successful return as a split point.
1976   PcDesc* mid = _pc_desc_cache.last_pc_desc();
1977   NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1978   if (mid->pc_offset() < pc_offset) {
1979     lower = mid;
1980   } else {
1981     upper = mid;
1982   }
1983 
1984   // Take giant steps at first (4096, then 256, then 16, then 1)
1985   const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
1986   const int RADIX = (1 << LOG2_RADIX);
1987   for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
1988     while ((mid = lower + step) < upper) {
1989       assert_LU_OK;
1990       NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
1991       if (mid->pc_offset() < pc_offset) {
1992         lower = mid;
1993       } else {
1994         upper = mid;
1995         break;
1996       }
1997     }
1998     assert_LU_OK;
1999   }
2000 
2001   // Sneak up on the value with a linear search of length ~16.
2002   while (true) {
2003     assert_LU_OK;
2004     mid = lower + 1;
2005     NOT_PRODUCT(++pc_nmethod_stats.pc_desc_searches);
2006     if (mid->pc_offset() < pc_offset) {
2007       lower = mid;
2008     } else {
2009       upper = mid;
2010       break;
2011     }
2012   }
2013 #undef assert_LU_OK
2014 
2015   if (match_desc(upper, pc_offset, approximate)) {
2016     assert(upper == linear_search(search, pc_offset, approximate), "search ok");
2017     _pc_desc_cache.add_pc_desc(upper);
2018     return upper;
2019   } else {
2020     assert(NULL == linear_search(search, pc_offset, approximate), "search ok");
2021     return NULL;
2022   }
2023 }
2024 
2025 
2026 void nmethod::check_all_dependencies(DepChange& changes) {
2027   // Checked dependencies are allocated into this ResourceMark
2028   ResourceMark rm;
2029 
2030   // Turn off dependency tracing while actually testing dependencies.
2031   NOT_PRODUCT( FlagSetting fs(TraceDependencies, false) );
2032 
2033   typedef ResourceHashtable<DependencySignature, int, &DependencySignature::hash,
2034                             &DependencySignature::equals, 11027> DepTable;
2035 
2036   DepTable* table = new DepTable();
2037 
2038   // Iterate over live nmethods and check dependencies of all nmethods that are not
2039   // marked for deoptimization. A particular dependency is only checked once.
2040   NMethodIterator iter(NMethodIterator::only_alive_and_not_unloading);
2041   while(iter.next()) {
2042     nmethod* nm = iter.method();
2043     // Only notify for live nmethods
2044     if (!nm->is_marked_for_deoptimization()) {
2045       for (Dependencies::DepStream deps(nm); deps.next(); ) {
2046         // Construct abstraction of a dependency.
2047         DependencySignature* current_sig = new DependencySignature(deps);
2048 
2049         // Determine if dependency is already checked. table->put(...) returns
2050         // 'true' if the dependency is added (i.e., was not in the hashtable).
2051         if (table->put(*current_sig, 1)) {
2052           if (deps.check_dependency() != NULL) {
2053             // Dependency checking failed. Print out information about the failed
2054             // dependency and finally fail with an assert. We can fail here, since
2055             // dependency checking is never done in a product build.
2056             tty->print_cr("Failed dependency:");
2057             changes.print();
2058             nm->print();
2059             nm->print_dependencies();
2060             assert(false, "Should have been marked for deoptimization");
2061           }
2062         }
2063       }
2064     }
2065   }
2066 }
2067 
2068 bool nmethod::check_dependency_on(DepChange& changes) {
2069   // What has happened:
2070   // 1) a new class dependee has been added
2071   // 2) dependee and all its super classes have been marked
2072   bool found_check = false;  // set true if we are upset
2073   for (Dependencies::DepStream deps(this); deps.next(); ) {
2074     // Evaluate only relevant dependencies.
2075     if (deps.spot_check_dependency_at(changes) != NULL) {
2076       found_check = true;
2077       NOT_DEBUG(break);
2078     }
2079   }
2080   return found_check;
2081 }
2082 
2083 // Called from mark_for_deoptimization, when dependee is invalidated.
2084 bool nmethod::is_dependent_on_method(Method* dependee) {
2085   for (Dependencies::DepStream deps(this); deps.next(); ) {
2086     if (deps.type() != Dependencies::evol_method)
2087       continue;
2088     Method* method = deps.method_argument(0);
2089     if (method == dependee) return true;
2090   }
2091   return false;
2092 }
2093 
2094 
2095 bool nmethod::is_patchable_at(address instr_addr) {
2096   assert(insts_contains(instr_addr), "wrong nmethod used");
2097   if (is_zombie()) {
2098     // a zombie may never be patched
2099     return false;
2100   }
2101   return true;
2102 }
2103 
2104 
2105 address nmethod::continuation_for_implicit_exception(address pc) {
2106   // Exception happened outside inline-cache check code => we are inside
2107   // an active nmethod => use cpc to determine a return address
2108   int exception_offset = pc - code_begin();
2109   int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
2110 #ifdef ASSERT
2111   if (cont_offset == 0) {
2112     Thread* thread = Thread::current();
2113     ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
2114     HandleMark hm(thread);
2115     ResourceMark rm(thread);
2116     CodeBlob* cb = CodeCache::find_blob(pc);
2117     assert(cb != NULL && cb == this, "");
2118     ttyLocker ttyl;
2119     tty->print_cr("implicit exception happened at " INTPTR_FORMAT, p2i(pc));
2120     // Print all available nmethod info.
2121     print_nmethod(true);
2122     method()->print_codes();
2123   }
2124 #endif
2125   if (cont_offset == 0) {
2126     // Let the normal error handling report the exception
2127     return NULL;
2128   }
2129   return code_begin() + cont_offset;
2130 }
2131 
2132 
2133 void nmethod_init() {
2134   // make sure you didn't forget to adjust the filler fields
2135   assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
2136 }
2137 
2138 
2139 //-------------------------------------------------------------------------------------------
2140 
2141 
2142 // QQQ might we make this work from a frame??
2143 nmethodLocker::nmethodLocker(address pc) {
2144   CodeBlob* cb = CodeCache::find_blob(pc);
2145   guarantee(cb != NULL && cb->is_compiled(), "bad pc for a nmethod found");
2146   _nm = cb->as_compiled_method();
2147   lock_nmethod(_nm);
2148 }
2149 
2150 // Only JvmtiDeferredEvent::compiled_method_unload_event()
2151 // should pass zombie_ok == true.
2152 void nmethodLocker::lock_nmethod(CompiledMethod* cm, bool zombie_ok) {
2153   if (cm == NULL)  return;
2154   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2155   nmethod* nm = cm->as_nmethod();
2156   Atomic::inc(&nm->_lock_count);
2157   assert(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method: %p", nm);
2158 }
2159 
2160 void nmethodLocker::unlock_nmethod(CompiledMethod* cm) {
2161   if (cm == NULL)  return;
2162   if (cm->is_aot()) return;  // FIXME: Revisit once _lock_count is added to aot_method
2163   nmethod* nm = cm->as_nmethod();
2164   Atomic::dec(&nm->_lock_count);
2165   assert(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
2166 }
2167 
2168 
2169 // -----------------------------------------------------------------------------
2170 // Verification
2171 
2172 class VerifyOopsClosure: public OopClosure {
2173   nmethod* _nm;
2174   bool     _ok;
2175 public:
2176   VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
2177   bool ok() { return _ok; }
2178   virtual void do_oop(oop* p) {
2179     if (oopDesc::is_oop_or_null(*p)) return;
2180     // Print diagnostic information before calling print_nmethod().
2181     // Assertions therein might prevent call from returning.
2182     tty->print_cr("*** non-oop " PTR_FORMAT " found at " PTR_FORMAT " (offset %d)",
2183                   p2i(*p), p2i(p), (int)((intptr_t)p - (intptr_t)_nm));
2184     if (_ok) {
2185       _nm->print_nmethod(true);
2186       _ok = false;
2187     }
2188   }
2189   virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
2190 };
2191 
2192 void nmethod::verify() {
2193 
2194   // Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
2195   // seems odd.
2196 
2197   if (is_zombie() || is_not_entrant() || is_unloaded())
2198     return;
2199 
2200   // Make sure all the entry points are correctly aligned for patching.
2201   NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
2202 
2203   // assert(oopDesc::is_oop(method()), "must be valid");
2204 
2205   ResourceMark rm;
2206 
2207   if (!CodeCache::contains(this)) {
2208     fatal("nmethod at " INTPTR_FORMAT " not in zone", p2i(this));
2209   }
2210 
2211   if(is_native_method() )
2212     return;
2213 
2214   nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
2215   if (nm != this) {
2216     fatal("findNMethod did not find this nmethod (" INTPTR_FORMAT ")", p2i(this));
2217   }
2218 
2219   for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2220     if (! p->verify(this)) {
2221       tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", p2i(this));
2222     }
2223   }
2224 
2225   VerifyOopsClosure voc(this);
2226   oops_do(&voc);
2227   assert(voc.ok(), "embedded oops must be OK");
2228   Universe::heap()->verify_nmethod(this);
2229 
2230   verify_scopes();
2231 }
2232 
2233 
2234 void nmethod::verify_interrupt_point(address call_site) {
2235   // Verify IC only when nmethod installation is finished.
2236   if (!is_not_installed()) {
2237     if (CompiledICLocker::is_safe(this)) {
2238       CompiledIC_at(this, call_site);
2239       CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
2240     } else {
2241       CompiledICLocker ml_verify(this);
2242       CompiledIC_at(this, call_site);
2243     }
2244   }
2245 
2246   PcDesc* pd = pc_desc_at(nativeCall_at(call_site)->return_address());
2247   assert(pd != NULL, "PcDesc must exist");
2248   for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
2249                                      pd->obj_decode_offset(), pd->should_reexecute(), pd->rethrow_exception(),
2250                                      pd->return_oop());
2251        !sd->is_top(); sd = sd->sender()) {
2252     sd->verify();
2253   }
2254 }
2255 
2256 void nmethod::verify_scopes() {
2257   if( !method() ) return;       // Runtime stubs have no scope
2258   if (method()->is_native()) return; // Ignore stub methods.
2259   // iterate through all interrupt point
2260   // and verify the debug information is valid.
2261   RelocIterator iter((nmethod*)this);
2262   while (iter.next()) {
2263     address stub = NULL;
2264     switch (iter.type()) {
2265       case relocInfo::virtual_call_type:
2266         verify_interrupt_point(iter.addr());
2267         break;
2268       case relocInfo::opt_virtual_call_type:
2269         stub = iter.opt_virtual_call_reloc()->static_stub(false);
2270         verify_interrupt_point(iter.addr());
2271         break;
2272       case relocInfo::static_call_type:
2273         stub = iter.static_call_reloc()->static_stub(false);
2274         //verify_interrupt_point(iter.addr());
2275         break;
2276       case relocInfo::runtime_call_type:
2277       case relocInfo::runtime_call_w_cp_type: {
2278         address destination = iter.reloc()->value();
2279         // Right now there is no way to find out which entries support
2280         // an interrupt point.  It would be nice if we had this
2281         // information in a table.
2282         break;
2283       }
2284       default:
2285         break;
2286     }
2287     assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
2288   }
2289 }
2290 
2291 
2292 // -----------------------------------------------------------------------------
2293 // Printing operations
2294 
2295 void nmethod::print() const {
2296   ttyLocker ttyl;   // keep the following output all in one block
2297   print(tty);
2298 }
2299 
2300 void nmethod::print(outputStream* st) const {
2301   ResourceMark rm;
2302 
2303   st->print("Compiled method ");
2304 
2305   if (is_compiled_by_c1()) {
2306     st->print("(c1) ");
2307   } else if (is_compiled_by_c2()) {
2308     st->print("(c2) ");
2309   } else if (is_compiled_by_jvmci()) {
2310     st->print("(JVMCI) ");
2311   } else {
2312     st->print("(n/a) ");
2313   }
2314 
2315   print_on(tty, NULL);
2316 
2317   if (WizardMode) {
2318     st->print("((nmethod*) " INTPTR_FORMAT ") ", p2i(this));
2319     st->print(" for method " INTPTR_FORMAT , p2i(method()));
2320     st->print(" { ");
2321     st->print_cr("%s ", state());
2322     st->print_cr("}:");
2323   }
2324   if (size              () > 0) st->print_cr(" total in heap  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2325                                              p2i(this),
2326                                              p2i(this) + size(),
2327                                              size());
2328   if (relocation_size   () > 0) st->print_cr(" relocation     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2329                                              p2i(relocation_begin()),
2330                                              p2i(relocation_end()),
2331                                              relocation_size());
2332   if (consts_size       () > 0) st->print_cr(" constants      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2333                                              p2i(consts_begin()),
2334                                              p2i(consts_end()),
2335                                              consts_size());
2336   if (insts_size        () > 0) st->print_cr(" main code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2337                                              p2i(insts_begin()),
2338                                              p2i(insts_end()),
2339                                              insts_size());
2340   if (stub_size         () > 0) st->print_cr(" stub code      [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2341                                              p2i(stub_begin()),
2342                                              p2i(stub_end()),
2343                                              stub_size());
2344   if (oops_size         () > 0) st->print_cr(" oops           [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2345                                              p2i(oops_begin()),
2346                                              p2i(oops_end()),
2347                                              oops_size());
2348   if (metadata_size     () > 0) st->print_cr(" metadata       [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2349                                              p2i(metadata_begin()),
2350                                              p2i(metadata_end()),
2351                                              metadata_size());
2352   if (scopes_data_size  () > 0) st->print_cr(" scopes data    [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2353                                              p2i(scopes_data_begin()),
2354                                              p2i(scopes_data_end()),
2355                                              scopes_data_size());
2356   if (scopes_pcs_size   () > 0) st->print_cr(" scopes pcs     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2357                                              p2i(scopes_pcs_begin()),
2358                                              p2i(scopes_pcs_end()),
2359                                              scopes_pcs_size());
2360   if (dependencies_size () > 0) st->print_cr(" dependencies   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2361                                              p2i(dependencies_begin()),
2362                                              p2i(dependencies_end()),
2363                                              dependencies_size());
2364   if (handler_table_size() > 0) st->print_cr(" handler table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2365                                              p2i(handler_table_begin()),
2366                                              p2i(handler_table_end()),
2367                                              handler_table_size());
2368   if (nul_chk_table_size() > 0) st->print_cr(" nul chk table  [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2369                                              p2i(nul_chk_table_begin()),
2370                                              p2i(nul_chk_table_end()),
2371                                              nul_chk_table_size());
2372 #if INCLUDE_JVMCI
2373   if (speculations_size () > 0) st->print_cr(" speculations   [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2374                                              p2i(speculations_begin()),
2375                                              p2i(speculations_end()),
2376                                              speculations_size());
2377   if (jvmci_data_size   () > 0) st->print_cr(" JVMCI data     [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
2378                                              p2i(jvmci_data_begin()),
2379                                              p2i(jvmci_data_end()),
2380                                              jvmci_data_size());
2381 #endif
2382 }
2383 
2384 void nmethod::print_code() {
2385   HandleMark hm;
2386   ResourceMark m;
2387   ttyLocker ttyl;
2388   // Call the specialized decode method of this class.
2389   decode(tty);
2390 }
2391 
2392 #ifndef PRODUCT  // called InstanceKlass methods are available only then. Declared as PRODUCT_RETURN
2393 
2394 void nmethod::print_dependencies() {
2395   ResourceMark rm;
2396   ttyLocker ttyl;   // keep the following output all in one block
2397   tty->print_cr("Dependencies:");
2398   for (Dependencies::DepStream deps(this); deps.next(); ) {
2399     deps.print_dependency();
2400     Klass* ctxk = deps.context_type();
2401     if (ctxk != NULL) {
2402       if (ctxk->is_instance_klass() && InstanceKlass::cast(ctxk)->is_dependent_nmethod(this)) {
2403         tty->print_cr("   [nmethod<=klass]%s", ctxk->external_name());
2404       }
2405     }
2406     deps.log_dependency();  // put it into the xml log also
2407   }
2408 }
2409 #endif
2410 
2411 #if defined(SUPPORT_DATA_STRUCTS)
2412 
2413 // Print the oops from the underlying CodeBlob.
2414 void nmethod::print_oops(outputStream* st) {
2415   HandleMark hm;
2416   ResourceMark m;
2417   st->print("Oops:");
2418   if (oops_begin() < oops_end()) {
2419     st->cr();
2420     for (oop* p = oops_begin(); p < oops_end(); p++) {
2421       Disassembler::print_location((unsigned char*)p, (unsigned char*)oops_begin(), (unsigned char*)oops_end(), st, true, false);
2422       st->print("0x%016lx ", *((unsigned long*)p));
2423       if (*p == Universe::non_oop_word()) {
2424         st->print_cr("NON_OOP");
2425         continue;  // skip non-oops
2426       }
2427       if (*p == NULL) {
2428         st->print_cr("LUCY: NULL-oop");
2429         continue;  // skip non-oops
2430       }
2431       (*p)->print_value_on(st);
2432       st->cr();
2433     }
2434   } else {
2435     st->print_cr(" <list empty>");
2436   }
2437 }
2438 
2439 // Print metadata pool.
2440 void nmethod::print_metadata(outputStream* st) {
2441   HandleMark hm;
2442   ResourceMark m;
2443   st->print("Metadata:");
2444   if (metadata_begin() < metadata_end()) {
2445     st->cr();
2446     for (Metadata** p = metadata_begin(); p < metadata_end(); p++) {
2447       Disassembler::print_location((unsigned char*)p, (unsigned char*)metadata_begin(), (unsigned char*)metadata_end(), st, true, false);
2448       st->print("0x%016lx ", *((unsigned long*)p));
2449       if (*p && *p != Universe::non_oop_word()) {
2450         (*p)->print_value_on(st);
2451       }
2452       st->cr();
2453     }
2454   } else {
2455     st->print_cr(" <list empty>");
2456   }
2457 }
2458 
2459 #ifndef PRODUCT  // ScopeDesc::print_on() is available only then. Declared as PRODUCT_RETURN
2460 void nmethod::print_scopes_on(outputStream* st) {
2461   // Find the first pc desc for all scopes in the code and print it.
2462   ResourceMark rm;
2463   st->print("scopes:");
2464   if (scopes_pcs_begin() < scopes_pcs_end()) {
2465     st->cr();
2466     for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2467       if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
2468         continue;
2469 
2470       ScopeDesc* sd = scope_desc_at(p->real_pc(this));
2471       while (sd != NULL) {
2472         sd->print_on(st, p);  // print output ends with a newline
2473         sd = sd->sender();
2474       }
2475     }
2476   } else {
2477     st->print_cr(" <list empty>");
2478   }
2479 }
2480 #endif
2481 
2482 #ifndef PRODUCT  // RelocIterator does support printing only then.
2483 void nmethod::print_relocations() {
2484   ResourceMark m;       // in case methods get printed via the debugger
2485   tty->print_cr("relocations:");
2486   RelocIterator iter(this);
2487   iter.print();
2488 }
2489 #endif
2490 
2491 void nmethod::print_pcs_on(outputStream* st) {
2492   ResourceMark m;       // in case methods get printed via debugger
2493   st->print("pc-bytecode offsets:");
2494   if (scopes_pcs_begin() < scopes_pcs_end()) {
2495     st->cr();
2496     for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
2497       p->print_on(st, this);  // print output ends with a newline
2498     }
2499   } else {
2500     st->print_cr(" <list empty>");
2501   }
2502 }
2503 
2504 void nmethod::print_handler_table() {
2505   ExceptionHandlerTable(this).print();
2506 }
2507 
2508 void nmethod::print_nul_chk_table() {
2509   ImplicitExceptionTable(this).print(code_begin());
2510 }
2511 
2512 void nmethod::print_recorded_oops() {
2513   const int n = oops_count();
2514   const int log_n = (n<10) ? 1 : (n<100) ? 2 : (n<1000) ? 3 : (n<10000) ? 4 : 6;
2515   tty->print("Recorded oops:");
2516   if (n > 0) {
2517     tty->cr();
2518     for (int i = 0; i < n; i++) {
2519       oop o = oop_at(i);
2520       tty->print("#%*d: " INTPTR_FORMAT " ", log_n, i, p2i(o));
2521       if (o == (oop)Universe::non_oop_word()) {
2522         tty->print("non-oop word");
2523       } else if (o == NULL) {
2524         tty->print("LUCY NULL-oop");
2525       } else {
2526         o->print_value_on(tty);
2527       }
2528       tty->cr();
2529     }
2530   } else {
2531     tty->print_cr(" <list empty>");
2532   }
2533 }
2534 
2535 void nmethod::print_recorded_metadata() {
2536   const int n = metadata_count();
2537   const int log_n = (n<10) ? 1 : (n<100) ? 2 : (n<1000) ? 3 : (n<10000) ? 4 : 6;
2538   tty->print("Recorded metadata:");
2539   if (n > 0) {
2540     tty->cr();
2541     for (int i = 0; i < n; i++) {
2542       Metadata* m = metadata_at(i);
2543       tty->print("#%*d: " INTPTR_FORMAT " ", log_n, i, p2i(m));
2544       if (m == (Metadata*)Universe::non_oop_word()) {
2545         tty->print("non-metadata word");
2546       } else if (m == NULL) {
2547         tty->print("LUCY NULL-oop");
2548       } else {
2549         Metadata::print_value_on_maybe_null(tty, m);
2550       }
2551       tty->cr();
2552     }
2553   } else {
2554     tty->print_cr(" <list empty>");
2555   }
2556 }
2557 #endif
2558 
2559 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
2560 
2561 void nmethod::print_constant_pool(outputStream* st) {
2562   //-----------------------------------
2563   //---<  Print the constant pool  >---
2564   //-----------------------------------
2565   int consts_size = this->consts_size();
2566   if ( consts_size > 0 ) {
2567     unsigned char* cstart = this->consts_begin();
2568     unsigned char* cp     = cstart;
2569     unsigned char* cend   = cp + consts_size;
2570     unsigned int   bytes_per_line = 4;
2571     unsigned int   CP_alignment   = 8;
2572     unsigned int   n;
2573 
2574     st->cr();
2575 
2576     //---<  print CP header to make clear what's printed  >---
2577     if( ((uintptr_t)cp&(CP_alignment-1)) == 0 ) {
2578       n = bytes_per_line;
2579       st->print_cr("[Constant Pool]");
2580       Disassembler::print_location(cp, cstart, cend, st, true, true);
2581       Disassembler::print_hexdata(cp, n, st, true);
2582       st->cr();
2583     } else {
2584       n = (uintptr_t)cp&(bytes_per_line-1);
2585       st->print_cr("[Constant Pool (unaligned)]");
2586     }
2587 
2588     //---<  print CP contents, bytes_per_line at a time  >---
2589     while (cp < cend) {
2590       Disassembler::print_location(cp, cstart, cend, st, true, false);
2591       Disassembler::print_hexdata(cp, n, st, false);
2592       cp += n;
2593       n   = bytes_per_line;
2594       st->cr();
2595     }
2596 
2597     //---<  Show potential alignment gap between constant pool and code  >---
2598     cend = code_begin();
2599     if( cp < cend ) {
2600       n = 4;
2601       st->print_cr("[Code entry alignment]");
2602       while (cp < cend) {
2603         Disassembler::print_location(cp, cstart, cend, st, false, false);
2604         cp += n;
2605         st->cr();
2606       }
2607     }
2608   } else {
2609     st->print_cr("[Constant Pool (empty)]");
2610   }
2611   st->cr();
2612 }
2613 
2614 #endif
2615 
2616 // Disassemble this nmethod.
2617 // Print additional debug information, if requested. This could be code
2618 // comments, block comments, profiling counters, etc.
2619 // The undisassembled format is useful no disassembler library is available.
2620 // The resulting hex dump (with markers) can be disassembled later, or on
2621 // another system, when/where a disassembler library is available.
2622 void nmethod::decode2(outputStream* ost) const {
2623 
2624   // Called from frame::back_trace_with_decode without ResourceMark.
2625   ResourceMark rm;
2626 
2627   // Make sure we have a valid stream to print on.
2628   outputStream* st = ost ? ost : tty;
2629 
2630 #if defined(SUPPORT_ABSTRACT_ASSEMBLY) && ! defined(SUPPORT_ASSEMBLY)
2631   const bool use_compressed_format    = true;
2632   const bool compressed_with_comments = use_compressed_format && (AbstractDisassembler::show_comment() ||
2633                                                                   AbstractDisassembler::show_block_comment());
2634 #else
2635   const bool use_compressed_format    = Disassembler::is_abstract();
2636   const bool compressed_with_comments = use_compressed_format && (AbstractDisassembler::show_comment() ||
2637                                                                   AbstractDisassembler::show_block_comment());
2638 #endif
2639 
2640   st->cr();
2641   this->print(st);
2642   st->cr();
2643 
2644 #if defined(SUPPORT_ASSEMBLY)
2645   //----------------------------------
2646   //---<  Print real disassembly  >---
2647   //----------------------------------
2648   if (! use_compressed_format) {
2649     Disassembler::decode(const_cast<nmethod*>(this), st);
2650     return;
2651   }
2652 #endif
2653 
2654 #if defined(SUPPORT_ABSTRACT_ASSEMBLY)
2655 
2656   // Compressed undisassembled disassembly format.
2657   // The following stati are defined/supported:
2658   //   = 0 - currently at bol() position, nothing printed yet on current line.
2659   //   = 1 - currently at position after print_location().
2660   //   > 1 - in the midst of printing instruction stream bytes.
2661   int        compressed_format_idx    = 0;
2662   int        code_comment_column      = 0;
2663   const int  instr_maxlen             = Assembler::instr_maxlen();
2664   const uint tabspacing               = 8;
2665   unsigned char* start = this->code_begin();
2666   unsigned char* p     = this->code_begin();
2667   unsigned char* end   = this->code_end();
2668   unsigned char* pss   = p; // start of a code section (used for offsets)
2669 
2670   if ((start == NULL) || (end == NULL)) {
2671     st->print_cr("PrintAssembly not possible due to uninitialized section pointers");
2672     return;
2673   }
2674 #endif
2675 
2676 #if defined(SUPPORT_ABSTRACT_ASSEMBLY)
2677   //---<  plain abstract disassembly, no comments or anything, just section headers  >---
2678   if (use_compressed_format && ! compressed_with_comments) {
2679     const_cast<nmethod*>(this)->print_constant_pool(st);
2680 
2681     //---<  Open the output (Marker for post-mortem disassembler)  >---
2682     st->print_cr("[MachCode]");
2683     const char* header = NULL;
2684     address p0 = p;
2685     while (p < end) {
2686       address pp = p;
2687       while ((p < end) && (header == NULL)) {
2688         header = nmethod_section_label(p);
2689         pp  = p;
2690         p  += Assembler::instr_len(p);
2691       }
2692       if (pp > p0) {
2693         AbstractDisassembler::decode_range_abstract(p0, pp, start, end, st, Assembler::instr_maxlen());
2694         p0 = pp;
2695         p  = pp;
2696         header = NULL;
2697       } else if (header != NULL) {
2698         st->bol();
2699         st->print_cr("%s", header);
2700         header = NULL;
2701       }
2702     }
2703     //---<  Close the output (Marker for post-mortem disassembler)  >---
2704     st->bol();
2705     st->print_cr("[/MachCode]");
2706     return;
2707   }
2708 #endif
2709 
2710 #if defined(SUPPORT_ABSTRACT_ASSEMBLY)
2711   //---<  abstract disassembly with comments and section headers merged in  >---
2712   if (compressed_with_comments) {
2713     const_cast<nmethod*>(this)->print_constant_pool(st);
2714 
2715     //---<  Open the output (Marker for post-mortem disassembler)  >---
2716     st->print_cr("[MachCode]");
2717     while ((p < end) && (p != NULL)) {
2718       const int instruction_size_in_bytes = Assembler::instr_len(p);
2719 
2720       //---<  Block comments for nmethod. Interrupts instruction stream, if any.  >---
2721       // Outputs a bol() before and a cr() after, but only if a comment is printed.
2722       // Prints nmethod_section_label as well.
2723       if (AbstractDisassembler::show_block_comment()) {
2724         print_block_comment(st, p);
2725         if (st->position() == 0) {
2726           compressed_format_idx = 0;
2727         }
2728       }
2729 
2730       //---<  New location information after line break  >---
2731       if (compressed_format_idx == 0) {
2732         code_comment_column   = Disassembler::print_location(p, pss, end, st, false, false);
2733         compressed_format_idx = 1;
2734       }
2735 
2736       //---<  Code comment for current instruction. Address range [p..(p+len))  >---
2737       unsigned char* p_end = p + (ssize_t)instruction_size_in_bytes;
2738       S390_ONLY(if (p_end > end) p_end = end;) // avoid getting past the end
2739 
2740       if (AbstractDisassembler::show_comment() && const_cast<nmethod*>(this)->has_code_comment(p, p_end)) {
2741         //---<  interrupt instruction byte stream for code comment  >---
2742         if (compressed_format_idx > 1) {
2743           st->cr();  // interrupt byte stream
2744           st->cr();  // add an empty line
2745           code_comment_column = Disassembler::print_location(p, pss, end, st, false, false);
2746         }
2747         const_cast<nmethod*>(this)->print_code_comment_on(st, code_comment_column, p, p_end );
2748         st->bol();
2749         compressed_format_idx = 0;
2750       }
2751 
2752       //---<  New location information after line break  >---
2753       if (compressed_format_idx == 0) {
2754         code_comment_column   = Disassembler::print_location(p, pss, end, st, false, false);
2755         compressed_format_idx = 1;
2756       }
2757 
2758       //---<  Nicely align instructions for readability  >---
2759       if (compressed_format_idx > 1) {
2760         Disassembler::print_delimiter(st);
2761       }
2762 
2763       //---<  Now, finally, print the actual instruction bytes  >---
2764       unsigned char* p0 = p;
2765       p = Disassembler::decode_instruction_abstract(p, st, instruction_size_in_bytes, instr_maxlen);
2766       compressed_format_idx += p - p0;
2767 
2768       if (Disassembler::start_newline(compressed_format_idx-1)) {
2769         st->cr();
2770         compressed_format_idx = 0;
2771       }
2772     }
2773     //---<  Close the output (Marker for post-mortem disassembler)  >---
2774     st->bol();
2775     st->print_cr("[/MachCode]");
2776     return;
2777   }
2778 #endif
2779 }
2780 
2781 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
2782 
2783 const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
2784   RelocIterator iter(this, begin, end);
2785   bool have_one = false;
2786   while (iter.next()) {
2787     have_one = true;
2788     switch (iter.type()) {
2789         case relocInfo::none:                  return "no_reloc";
2790         case relocInfo::oop_type: {
2791           // Get a non-resizable resource-allocated stringStream.
2792           // Our callees make use of (nested) ResourceMarks.
2793           stringStream st(NEW_RESOURCE_ARRAY(char, 1024), 1024);
2794           oop_Relocation* r = iter.oop_reloc();
2795           oop obj = r->oop_value();
2796           st.print("oop(");
2797           if (obj == NULL) st.print("NULL");
2798           else obj->print_value_on(&st);
2799           st.print(")");
2800           return st.as_string();
2801         }
2802         case relocInfo::metadata_type: {
2803           stringStream st;
2804           metadata_Relocation* r = iter.metadata_reloc();
2805           Metadata* obj = r->metadata_value();
2806           st.print("metadata(");
2807           if (obj == NULL) st.print("NULL");
2808           else obj->print_value_on(&st);
2809           st.print(")");
2810           return st.as_string();
2811         }
2812         case relocInfo::runtime_call_type:
2813         case relocInfo::runtime_call_w_cp_type: {
2814           stringStream st;
2815           st.print("runtime_call");
2816           CallRelocation* r = (CallRelocation*)iter.reloc();
2817           address dest = r->destination();
2818           CodeBlob* cb = CodeCache::find_blob(dest);
2819           if (cb != NULL) {
2820             st.print(" %s", cb->name());
2821           } else {
2822             ResourceMark rm;
2823             const int buflen = 1024;
2824             char* buf = NEW_RESOURCE_ARRAY(char, buflen);
2825             int offset;
2826             if (os::dll_address_to_function_name(dest, buf, buflen, &offset)) {
2827               st.print(" %s", buf);
2828               if (offset != 0) {
2829                 st.print("+%d", offset);
2830               }
2831             }
2832           }
2833           return st.as_string();
2834         }
2835         case relocInfo::virtual_call_type: {
2836           stringStream st;
2837           st.print_raw("virtual_call");
2838           virtual_call_Relocation* r = iter.virtual_call_reloc();
2839           Method* m = r->method_value();
2840           if (m != NULL) {
2841             assert(m->is_method(), "");
2842             m->print_short_name(&st);
2843           }
2844           return st.as_string();
2845         }
2846         case relocInfo::opt_virtual_call_type: {
2847           stringStream st;
2848           st.print_raw("optimized virtual_call");
2849           opt_virtual_call_Relocation* r = iter.opt_virtual_call_reloc();
2850           Method* m = r->method_value();
2851           if (m != NULL) {
2852             assert(m->is_method(), "");
2853             m->print_short_name(&st);
2854           }
2855           return st.as_string();
2856         }
2857         case relocInfo::static_call_type: {
2858           stringStream st;
2859           st.print_raw("static_call");
2860           static_call_Relocation* r = iter.static_call_reloc();
2861           Method* m = r->method_value();
2862           if (m != NULL) {
2863             assert(m->is_method(), "");
2864             m->print_short_name(&st);
2865           }
2866           return st.as_string();
2867         }
2868         case relocInfo::static_stub_type:      return "static_stub";
2869         case relocInfo::external_word_type:    return "external_word";
2870         case relocInfo::internal_word_type:    return "internal_word";
2871         case relocInfo::section_word_type:     return "section_word";
2872         case relocInfo::poll_type:             return "poll";
2873         case relocInfo::poll_return_type:      return "poll_return";
2874         case relocInfo::trampoline_stub_type:  return "trampoline_stub";
2875         case relocInfo::type_mask:             return "type_bit_mask";
2876 
2877         default:
2878           break;
2879     }
2880   }
2881   return have_one ? "other" : NULL;
2882 }
2883 
2884 // Return a the last scope in (begin..end]
2885 ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
2886   PcDesc* p = pc_desc_near(begin+1);
2887   if (p != NULL && p->real_pc(this) <= end) {
2888     return new ScopeDesc(this, p->scope_decode_offset(),
2889                          p->obj_decode_offset(), p->should_reexecute(), p->rethrow_exception(),
2890                          p->return_oop());
2891   }
2892   return NULL;
2893 }
2894 
2895 const char* nmethod::nmethod_section_label(address pos) const {
2896   const char* label = NULL;
2897   if (pos == code_begin())                                              label = "[Instructions begin]";
2898   if (pos == entry_point())                                             label = "[Entry Point]";
2899   if (pos == verified_entry_point())                                    label = "[Verified Entry Point]";
2900   if (has_method_handle_invokes() && (pos == deopt_mh_handler_begin())) label = "[Deopt MH Handler Code]";
2901   if (pos == consts_begin() && pos != insts_begin())                    label = "[Constants]";
2902   // Check stub_code before checking exception_handler or deopt_handler.
2903   if (pos == this->stub_begin())                                        label = "[Stub Code]";
2904   if (JVMCI_ONLY(_exception_offset >= 0 &&) pos == exception_begin())           label = "[Exception Handler]";
2905   if (JVMCI_ONLY(_deopt_handler_begin != NULL &&) pos == deopt_handler_begin()) label = "[Deopt Handler Code]";
2906   return label;
2907 }
2908 
2909 void nmethod::print_nmethod_labels(outputStream* stream, address block_begin, bool print_section_labels) const {
2910   if (print_section_labels) {
2911     const char* label = nmethod_section_label(block_begin);
2912     if (label != NULL) {
2913       stream->bol();
2914       stream->print_cr("%s", label);
2915     }
2916   }
2917 
2918   if (block_begin == entry_point()) {
2919     methodHandle m = method();
2920     if (m.not_null()) {
2921       stream->print("  # ");
2922       m->print_value_on(stream);
2923       stream->cr();
2924     }
2925     if (m.not_null() && !is_osr_method()) {
2926       ResourceMark rm;
2927       int sizeargs = m->size_of_parameters();
2928       BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
2929       VMRegPair* regs   = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
2930       {
2931         int sig_index = 0;
2932         if (!m->is_static())
2933           sig_bt[sig_index++] = T_OBJECT; // 'this'
2934         for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
2935           BasicType t = ss.type();
2936           sig_bt[sig_index++] = t;
2937           if (type2size[t] == 2) {
2938             sig_bt[sig_index++] = T_VOID;
2939           } else {
2940             assert(type2size[t] == 1, "size is 1 or 2");
2941           }
2942         }
2943         assert(sig_index == sizeargs, "");
2944       }
2945       const char* spname = "sp"; // make arch-specific?
2946       intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
2947       int stack_slot_offset = this->frame_size() * wordSize;
2948       int tab1 = 14, tab2 = 24;
2949       int sig_index = 0;
2950       int arg_index = (m->is_static() ? 0 : -1);
2951       bool did_old_sp = false;
2952       for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
2953         bool at_this = (arg_index == -1);
2954         bool at_old_sp = false;
2955         BasicType t = (at_this ? T_OBJECT : ss.type());
2956         assert(t == sig_bt[sig_index], "sigs in sync");
2957         if (at_this)
2958           stream->print("  # this: ");
2959         else
2960           stream->print("  # parm%d: ", arg_index);
2961         stream->move_to(tab1);
2962         VMReg fst = regs[sig_index].first();
2963         VMReg snd = regs[sig_index].second();
2964         if (fst->is_reg()) {
2965           stream->print("%s", fst->name());
2966           if (snd->is_valid())  {
2967             stream->print(":%s", snd->name());
2968           }
2969         } else if (fst->is_stack()) {
2970           int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
2971           if (offset == stack_slot_offset)  at_old_sp = true;
2972           stream->print("[%s+0x%x]", spname, offset);
2973         } else {
2974           stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
2975         }
2976         stream->print(" ");
2977         stream->move_to(tab2);
2978         stream->print("= ");
2979         if (at_this) {
2980           m->method_holder()->print_value_on(stream);
2981         } else {
2982           bool did_name = false;
2983           if (!at_this && ss.is_object()) {
2984             Symbol* name = ss.as_symbol_or_null();
2985             if (name != NULL) {
2986               name->print_value_on(stream);
2987               did_name = true;
2988             }
2989           }
2990           if (!did_name)
2991             stream->print("%s", type2name(t));
2992         }
2993         if (at_old_sp) {
2994           stream->print("  (%s of caller)", spname);
2995           did_old_sp = true;
2996         }
2997         stream->cr();
2998         sig_index += type2size[t];
2999         arg_index += 1;
3000         if (!at_this)  ss.next();
3001       }
3002       if (!did_old_sp) {
3003         stream->print("  # ");
3004         stream->move_to(tab1);
3005         stream->print("[%s+0x%x]", spname, stack_slot_offset);
3006         stream->print("  (%s of caller)", spname);
3007         stream->cr();
3008       }
3009     }
3010   }
3011 }
3012 
3013 // Returns whether this nmethod has code comments.
3014 bool nmethod::has_code_comment(address begin, address end) {
3015   // scopes?
3016   ScopeDesc* sd  = scope_desc_in(begin, end);
3017   if (sd != NULL) return true;
3018 
3019   // relocations?
3020   const char* str = reloc_string_for(begin, end);
3021   if (str != NULL) return true;
3022 
3023   // implicit exceptions?
3024   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
3025   if (cont_offset != 0) return true;
3026 
3027   return false;
3028 }
3029 
3030 void nmethod::print_code_comment_on(outputStream* st, int column, address begin, address end) {
3031   // First, find an oopmap in (begin, end].
3032   // We use the odd half-closed interval so that oop maps and scope descs
3033   // which are tied to the byte after a call are printed with the call itself.
3034   address base = code_begin();
3035   ImmutableOopMapSet* oms = oop_maps();
3036   if (oms != NULL) {
3037     for (int i = 0, imax = oms->count(); i < imax; i++) {
3038       const ImmutableOopMapPair* pair = oms->pair_at(i);
3039       const ImmutableOopMap* om = pair->get_from(oms);
3040       address pc = base + pair->pc_offset();
3041       if (pc > begin) {
3042         if (pc <= end) {
3043           st->move_to(column, 6, 0);
3044           st->print("; ");
3045           om->print_on(st);
3046         }
3047         break;
3048       }
3049     }
3050   }
3051 
3052   // Print any debug info present at this pc.
3053   ScopeDesc* sd  = scope_desc_in(begin, end);
3054   if (sd != NULL) {
3055     st->move_to(column, 6, 0);
3056     if (sd->bci() == SynchronizationEntryBCI) {
3057       st->print(";*synchronization entry");
3058     } else if (sd->bci() == AfterBci) {
3059       st->print(";* method exit (unlocked if synchronized)");
3060     } else if (sd->bci() == UnwindBci) {
3061       st->print(";* unwind (locked if synchronized)");
3062     } else if (sd->bci() == AfterExceptionBci) {
3063       st->print(";* unwind (unlocked if synchronized)");
3064     } else if (sd->bci() == UnknownBci) {
3065       st->print(";* unknown");
3066     } else if (sd->bci() == InvalidFrameStateBci) {
3067       st->print(";* invalid frame state");
3068     } else {
3069       if (sd->method() == NULL) {
3070         st->print("method is NULL");
3071       } else if (sd->method()->is_native()) {
3072         st->print("method is native");
3073       } else {
3074         Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
3075         st->print(";*%s", Bytecodes::name(bc));
3076         switch (bc) {
3077         case Bytecodes::_invokevirtual:
3078         case Bytecodes::_invokespecial:
3079         case Bytecodes::_invokestatic:
3080         case Bytecodes::_invokeinterface:
3081           {
3082             Bytecode_invoke invoke(sd->method(), sd->bci());
3083             st->print(" ");
3084             if (invoke.name() != NULL)
3085               invoke.name()->print_symbol_on(st);
3086             else
3087               st->print("<UNKNOWN>");
3088             break;
3089           }
3090         case Bytecodes::_getfield:
3091         case Bytecodes::_putfield:
3092         case Bytecodes::_getstatic:
3093         case Bytecodes::_putstatic:
3094           {
3095             Bytecode_field field(sd->method(), sd->bci());
3096             st->print(" ");
3097             if (field.name() != NULL)
3098               field.name()->print_symbol_on(st);
3099             else
3100               st->print("<UNKNOWN>");
3101           }
3102         default:
3103           break;
3104         }
3105       }
3106       st->print(" {reexecute=%d rethrow=%d return_oop=%d}", sd->should_reexecute(), sd->rethrow_exception(), sd->return_oop());
3107     }
3108 
3109     // Print all scopes
3110     for (;sd != NULL; sd = sd->sender()) {
3111       st->move_to(column, 6, 0);
3112       st->print("; -");
3113       if (sd->should_reexecute()) {
3114         st->print(" (reexecute)");
3115       }
3116       if (sd->method() == NULL) {
3117         st->print("method is NULL");
3118       } else {
3119         sd->method()->print_short_name(st);
3120       }
3121       int lineno = sd->method()->line_number_from_bci(sd->bci());
3122       if (lineno != -1) {
3123         st->print("@%d (line %d)", sd->bci(), lineno);
3124       } else {
3125         st->print("@%d", sd->bci());
3126       }
3127       st->cr();
3128     }
3129   }
3130 
3131   // Print relocation information
3132   // Prevent memory leak: allocating without ResourceMark.
3133   ResourceMark rm;
3134   const char* str = reloc_string_for(begin, end);
3135   if (str != NULL) {
3136     if (sd != NULL) st->cr();
3137     st->move_to(column, 6, 0);
3138     st->print(";   {%s}", str);
3139   }
3140   int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
3141   if (cont_offset != 0) {
3142     st->move_to(column, 6, 0);
3143     st->print("; implicit exception: dispatches to " INTPTR_FORMAT, p2i(code_begin() + cont_offset));
3144   }
3145 
3146 }
3147 
3148 #endif
3149 
3150 class DirectNativeCallWrapper: public NativeCallWrapper {
3151 private:
3152   NativeCall* _call;
3153 
3154 public:
3155   DirectNativeCallWrapper(NativeCall* call) : _call(call) {}
3156 
3157   virtual address destination() const { return _call->destination(); }
3158   virtual address instruction_address() const { return _call->instruction_address(); }
3159   virtual address next_instruction_address() const { return _call->next_instruction_address(); }
3160   virtual address return_address() const { return _call->return_address(); }
3161 
3162   virtual address get_resolve_call_stub(bool is_optimized) const {
3163     if (is_optimized) {
3164       return SharedRuntime::get_resolve_opt_virtual_call_stub();
3165     }
3166     return SharedRuntime::get_resolve_virtual_call_stub();
3167   }
3168 
3169   virtual void set_destination_mt_safe(address dest) {
3170 #if INCLUDE_AOT
3171     if (UseAOT) {
3172       CodeBlob* callee = CodeCache::find_blob(dest);
3173       CompiledMethod* cm = callee->as_compiled_method_or_null();
3174       if (cm != NULL && cm->is_far_code()) {
3175         // Temporary fix, see JDK-8143106
3176         CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
3177         csc->set_to_far(methodHandle(cm->method()), dest);
3178         return;
3179       }
3180     }
3181 #endif
3182     _call->set_destination_mt_safe(dest);
3183   }
3184 
3185   virtual void set_to_interpreted(const methodHandle& method, CompiledICInfo& info) {
3186     CompiledDirectStaticCall* csc = CompiledDirectStaticCall::at(instruction_address());
3187 #if INCLUDE_AOT
3188     if (info.to_aot()) {
3189       csc->set_to_far(method, info.entry());
3190     } else
3191 #endif
3192     {
3193       csc->set_to_interpreted(method, info.entry());
3194     }
3195   }
3196 
3197   virtual void verify() const {
3198     // make sure code pattern is actually a call imm32 instruction
3199     _call->verify();
3200     _call->verify_alignment();
3201   }
3202 
3203   virtual void verify_resolve_call(address dest) const {
3204     CodeBlob* db = CodeCache::find_blob_unsafe(dest);
3205     assert(db != NULL && !db->is_adapter_blob(), "must use stub!");
3206   }
3207 
3208   virtual bool is_call_to_interpreted(address dest) const {
3209     CodeBlob* cb = CodeCache::find_blob(_call->instruction_address());
3210     return cb->contains(dest);
3211   }
3212 
3213   virtual bool is_safe_for_patching() const { return false; }
3214 
3215   virtual NativeInstruction* get_load_instruction(virtual_call_Relocation* r) const {
3216     return nativeMovConstReg_at(r->cached_value());
3217   }
3218 
3219   virtual void *get_data(NativeInstruction* instruction) const {
3220     return (void*)((NativeMovConstReg*) instruction)->data();
3221   }
3222 
3223   virtual void set_data(NativeInstruction* instruction, intptr_t data) {
3224     ((NativeMovConstReg*) instruction)->set_data(data);
3225   }
3226 };
3227 
3228 NativeCallWrapper* nmethod::call_wrapper_at(address call) const {
3229   return new DirectNativeCallWrapper((NativeCall*) call);
3230 }
3231 
3232 NativeCallWrapper* nmethod::call_wrapper_before(address return_pc) const {
3233   return new DirectNativeCallWrapper(nativeCall_before(return_pc));
3234 }
3235 
3236 address nmethod::call_instruction_address(address pc) const {
3237   if (NativeCall::is_call_before(pc)) {
3238     NativeCall *ncall = nativeCall_before(pc);
3239     return ncall->instruction_address();
3240   }
3241   return NULL;
3242 }
3243 
3244 CompiledStaticCall* nmethod::compiledStaticCall_at(Relocation* call_site) const {
3245   return CompiledDirectStaticCall::at(call_site);
3246 }
3247 
3248 CompiledStaticCall* nmethod::compiledStaticCall_at(address call_site) const {
3249   return CompiledDirectStaticCall::at(call_site);
3250 }
3251 
3252 CompiledStaticCall* nmethod::compiledStaticCall_before(address return_addr) const {
3253   return CompiledDirectStaticCall::before(return_addr);
3254 }
3255 
3256 #if defined(SUPPORT_DATA_STRUCTS)
3257 void nmethod::print_value_on(outputStream* st) const {
3258   st->print("nmethod");
3259   print_on(st, NULL);
3260 }
3261 #endif
3262 
3263 #ifndef PRODUCT
3264 
3265 void nmethod::print_calls(outputStream* st) {
3266   RelocIterator iter(this);
3267   while (iter.next()) {
3268     switch (iter.type()) {
3269     case relocInfo::virtual_call_type:
3270     case relocInfo::opt_virtual_call_type: {
3271       CompiledICLocker ml_verify(this);
3272       CompiledIC_at(&iter)->print();
3273       break;
3274     }
3275     case relocInfo::static_call_type:
3276       st->print_cr("Static call at " INTPTR_FORMAT, p2i(iter.reloc()->addr()));
3277       CompiledDirectStaticCall::at(iter.reloc())->print();
3278       break;
3279     default:
3280       break;
3281     }
3282   }
3283 }
3284 
3285 void nmethod::print_statistics() {
3286   ttyLocker ttyl;
3287   if (xtty != NULL)  xtty->head("statistics type='nmethod'");
3288   native_nmethod_stats.print_native_nmethod_stats();
3289 #ifdef COMPILER1
3290   c1_java_nmethod_stats.print_nmethod_stats("C1");
3291 #endif
3292 #ifdef COMPILER2
3293   c2_java_nmethod_stats.print_nmethod_stats("C2");
3294 #endif
3295 #if INCLUDE_JVMCI
3296   jvmci_java_nmethod_stats.print_nmethod_stats("JVMCI");
3297 #endif
3298   unknown_java_nmethod_stats.print_nmethod_stats("Unknown");
3299   DebugInformationRecorder::print_statistics();
3300 #ifndef PRODUCT
3301   pc_nmethod_stats.print_pc_stats();
3302 #endif
3303   Dependencies::print_statistics();
3304   if (xtty != NULL)  xtty->tail("statistics");
3305 }
3306 
3307 #endif // !PRODUCT
3308 
3309 #if INCLUDE_JVMCI
3310 void nmethod::update_speculation(JavaThread* thread) {
3311   jlong speculation = thread->pending_failed_speculation();
3312   if (speculation != 0) {
3313     guarantee(jvmci_nmethod_data() != NULL, "failed speculation in nmethod without failed speculation list");
3314     jvmci_nmethod_data()->add_failed_speculation(this, speculation);
3315     thread->set_pending_failed_speculation(0);
3316   }
3317 }
3318 
3319 const char* nmethod::jvmci_name() {
3320   if (jvmci_nmethod_data() != NULL) {
3321     return jvmci_nmethod_data()->name();
3322   }
3323   return NULL;
3324 }
3325 #endif