1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   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.
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   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).
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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  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.
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  24 
  25 #ifndef SHARE_CODE_NMETHOD_HPP
  26 #define SHARE_CODE_NMETHOD_HPP
  27 
  28 #include "code/codeBlob.hpp"
  29 #include "code/pcDesc.hpp"
  30 #include "compiler/compilerDefinitions.hpp"
  31 #include "oops/metadata.hpp"
  32 #include "oops/method.hpp"
  33 
  34 class AbstractCompiler;
  35 class CompiledDirectCall;
  36 class CompiledIC;
  37 class CompiledICData;
  38 class CompileTask;
  39 class DepChange;
  40 class Dependencies;
  41 class DirectiveSet;
  42 class DebugInformationRecorder;
  43 class ExceptionHandlerTable;
  44 class ImplicitExceptionTable;
  45 class JvmtiThreadState;
  46 class MetadataClosure;
  47 class NativeCallWrapper;
  48 class OopIterateClosure;
  49 class ScopeDesc;
  50 class xmlStream;
  51 
  52 // This class is used internally by nmethods, to cache
  53 // exception/pc/handler information.
  54 
  55 class ExceptionCache : public CHeapObj<mtCode> {
  56   friend class VMStructs;
  57  private:
  58   enum { cache_size = 16 };
  59   Klass*   _exception_type;
  60   address  _pc[cache_size];
  61   address  _handler[cache_size];
  62   volatile int _count;
  63   ExceptionCache* volatile _next;
  64   ExceptionCache* _purge_list_next;
  65 
  66   inline address pc_at(int index);
  67   void set_pc_at(int index, address a)      { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
  68 
  69   inline address handler_at(int index);
  70   void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
  71 
  72   inline int count();
  73   // increment_count is only called under lock, but there may be concurrent readers.
  74   void increment_count();
  75 
  76  public:
  77 
  78   ExceptionCache(Handle exception, address pc, address handler);
  79 
  80   Klass*    exception_type()                { return _exception_type; }
  81   ExceptionCache* next();
  82   void      set_next(ExceptionCache *ec);
  83   ExceptionCache* purge_list_next()                 { return _purge_list_next; }
  84   void      set_purge_list_next(ExceptionCache *ec) { _purge_list_next = ec; }
  85 
  86   address match(Handle exception, address pc);
  87   bool    match_exception_with_space(Handle exception) ;
  88   address test_address(address addr);
  89   bool    add_address_and_handler(address addr, address handler) ;
  90 };
  91 
  92 // cache pc descs found in earlier inquiries
  93 class PcDescCache {
  94   friend class VMStructs;
  95  private:
  96   enum { cache_size = 4 };
  97   // The array elements MUST be volatile! Several threads may modify
  98   // and read from the cache concurrently. find_pc_desc_internal has
  99   // returned wrong results. C++ compiler (namely xlC12) may duplicate
 100   // C++ field accesses if the elements are not volatile.
 101   typedef PcDesc* PcDescPtr;
 102   volatile PcDescPtr _pc_descs[cache_size]; // last cache_size pc_descs found
 103  public:
 104   PcDescCache() { debug_only(_pc_descs[0] = nullptr); }
 105   void    init_to(PcDesc* initial_pc_desc);
 106   PcDesc* find_pc_desc(int pc_offset, bool approximate);
 107   void    add_pc_desc(PcDesc* pc_desc);
 108   PcDesc* last_pc_desc() { return _pc_descs[0]; }
 109 };
 110 
 111 class PcDescContainer : public CHeapObj<mtCode> {
 112 private:
 113   PcDescCache _pc_desc_cache;
 114 public:
 115   PcDescContainer(PcDesc* initial_pc_desc) { _pc_desc_cache.init_to(initial_pc_desc); }
 116 
 117   PcDesc* find_pc_desc_internal(address pc, bool approximate, address code_begin,
 118                                 PcDesc* lower, PcDesc* upper);
 119 
 120   PcDesc* find_pc_desc(address pc, bool approximate, address code_begin, PcDesc* lower, PcDesc* upper)
 121 #ifdef PRODUCT
 122   {
 123     PcDesc* desc = _pc_desc_cache.last_pc_desc();
 124     assert(desc != nullptr, "PcDesc cache should be initialized already");
 125     if (desc->pc_offset() == (pc - code_begin)) {
 126       // Cached value matched
 127       return desc;
 128     }
 129     return find_pc_desc_internal(pc, approximate, code_begin, lower, upper);
 130   }
 131 #endif
 132   ;
 133 };
 134 
 135 // nmethods (native methods) are the compiled code versions of Java methods.
 136 //
 137 // An nmethod contains:
 138 //  - header                 (the nmethod structure)
 139 //  [Relocation]
 140 //  - relocation information
 141 //  - constant part          (doubles, longs and floats used in nmethod)
 142 //  - oop table
 143 //  [Code]
 144 //  - code body
 145 //  - exception handler
 146 //  - stub code
 147 //  [Debugging information]
 148 //  - oop array
 149 //  - data array
 150 //  - pcs
 151 //  [Exception handler table]
 152 //  - handler entry point array
 153 //  [Implicit Null Pointer exception table]
 154 //  - implicit null table array
 155 //  [Speculations]
 156 //  - encoded speculations array
 157 //  [JVMCINMethodData]
 158 //  - meta data for JVMCI compiled nmethod
 159 
 160 #if INCLUDE_JVMCI
 161 class FailedSpeculation;
 162 class JVMCINMethodData;
 163 #endif
 164 
 165 class nmethod : public CodeBlob {
 166   friend class VMStructs;
 167   friend class JVMCIVMStructs;
 168   friend class CodeCache;  // scavengable oops
 169   friend class JVMCINMethodData;
 170   friend class DeoptimizationScope;
 171 
 172  private:
 173 
 174   // Used to track in which deoptimize handshake this method will be deoptimized.
 175   uint64_t  _deoptimization_generation;
 176 
 177   uint64_t  _gc_epoch;
 178 
 179   Method*   _method;
 180 
 181   // To reduce header size union fields which usages do not overlap.
 182   union {
 183     // To support simple linked-list chaining of nmethods:
 184     nmethod*  _osr_link; // from InstanceKlass::osr_nmethods_head
 185     struct {
 186       // These are used for compiled synchronized native methods to
 187       // locate the owner and stack slot for the BasicLock. They are
 188       // needed because there is no debug information for compiled native
 189       // wrappers and the oop maps are insufficient to allow
 190       // frame::retrieve_receiver() to work. Currently they are expected
 191       // to be byte offsets from the Java stack pointer for maximum code
 192       // sharing between platforms. JVMTI's GetLocalInstance() uses these
 193       // offsets to find the receiver for non-static native wrapper frames.
 194       ByteSize _native_receiver_sp_offset;
 195       ByteSize _native_basic_lock_sp_offset;
 196     };
 197   };
 198 
 199   // nmethod's read-only data
 200   address _immutable_data;
 201 
 202   PcDescContainer* _pc_desc_container;
 203   ExceptionCache* volatile _exception_cache;
 204 
 205   void* _gc_data;
 206 
 207   struct oops_do_mark_link; // Opaque data type.
 208   static nmethod*    volatile _oops_do_mark_nmethods;
 209   oops_do_mark_link* volatile _oops_do_mark_link;
 210 
 211   CompiledICData* _compiled_ic_data;
 212 
 213   // offsets for entry points
 214   address  _osr_entry_point;       // entry point for on stack replacement
 215   uint16_t _entry_offset;          // entry point with class check
 216   uint16_t _verified_entry_offset; // entry point without class check
 217   // TODO: can these be uint16_t, seem rely on -1 CodeOffset, can change later...
 218   address _inline_entry_point;              // inline type entry point (unpack all inline type args) with class check
 219   address _verified_inline_entry_point;     // inline type entry point (unpack all inline type args) without class check
 220   address _verified_inline_ro_entry_point;  // inline type entry point (unpack receiver only) without class check
 221   int      _entry_bci;             // != InvocationEntryBci if this nmethod is an on-stack replacement method
 222   int      _immutable_data_size;
 223 
 224   // _consts_offset == _content_offset because SECT_CONSTS is first in code buffer
 225 
 226   int _skipped_instructions_size;
 227 
 228   int _stub_offset;
 229 
 230   // Offsets for different stubs section parts
 231   int _exception_offset;
 232   // All deoptee's will resume execution at this location described by
 233   // this offset.
 234   int _deopt_handler_offset;
 235   // All deoptee's at a MethodHandle call site will resume execution
 236   // at this location described by this offset.
 237   int _deopt_mh_handler_offset;
 238   // Offset (from insts_end) of the unwind handler if it exists
 239   int16_t  _unwind_handler_offset;
 240   // Number of arguments passed on the stack
 241   uint16_t _num_stack_arg_slots;
 242 
 243   // Offsets in mutable data section
 244   // _oops_offset == _data_offset,  offset where embedded oop table begins (inside data)
 245   uint16_t _metadata_offset; // embedded meta data table
 246 #if INCLUDE_JVMCI
 247   uint16_t _jvmci_data_offset;
 248 #endif
 249 
 250   // Offset in immutable data section
 251   // _dependencies_offset == 0
 252   uint16_t _nul_chk_table_offset;
 253   uint16_t _handler_table_offset; // This table could be big in C1 code
 254   int      _scopes_pcs_offset;
 255   int      _scopes_data_offset;
 256 #if INCLUDE_JVMCI
 257   int      _speculations_offset;
 258 #endif
 259 
 260   // location in frame (offset for sp) that deopt can store the original
 261   // pc during a deopt.
 262   int _orig_pc_offset;
 263 
 264   int          _compile_id;            // which compilation made this nmethod
 265   CompLevel    _comp_level;            // compilation level (s1)
 266   CompilerType _compiler_type;         // which compiler made this nmethod (u1)
 267 
 268   // Local state used to keep track of whether unloading is happening or not
 269   volatile uint8_t _is_unloading_state;
 270 
 271   // Protected by NMethodState_lock
 272   volatile signed char _state;         // {not_installed, in_use, not_entrant}
 273 
 274   // set during construction
 275   uint8_t _has_unsafe_access:1,        // May fault due to unsafe access.
 276           _has_method_handle_invokes:1,// Has this method MethodHandle invokes?
 277           _has_wide_vectors:1,         // Preserve wide vectors at safepoints
 278           _has_monitors:1,             // Fastpath monitor detection for continuations
 279           _has_flushed_dependencies:1, // Used for maintenance of dependencies (under CodeCache_lock)
 280           _is_unlinked:1,              // mark during class unloading
 281           _load_reported:1;            // used by jvmti to track if an event has been posted for this nmethod
 282 
 283   enum DeoptimizationStatus : u1 {
 284     not_marked,
 285     deoptimize,
 286     deoptimize_noupdate,
 287     deoptimize_done
 288   };
 289 
 290   volatile DeoptimizationStatus _deoptimization_status; // Used for stack deoptimization
 291 
 292   DeoptimizationStatus deoptimization_status() const {
 293     return Atomic::load(&_deoptimization_status);
 294   }
 295 
 296   // Initialize fields to their default values
 297   void init_defaults(CodeBuffer *code_buffer, CodeOffsets* offsets);
 298 
 299   // Post initialization
 300   void post_init();
 301 
 302   // For native wrappers
 303   nmethod(Method* method,
 304           CompilerType type,
 305           int nmethod_size,
 306           int compile_id,
 307           CodeOffsets* offsets,
 308           CodeBuffer *code_buffer,
 309           int frame_size,
 310           ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
 311           ByteSize basic_lock_sp_offset,       /* synchronized natives only */
 312           OopMapSet* oop_maps);
 313 
 314   // For normal JIT compiled code
 315   nmethod(Method* method,
 316           CompilerType type,
 317           int nmethod_size,
 318           int immutable_data_size,
 319           int compile_id,
 320           int entry_bci,
 321           address immutable_data,
 322           CodeOffsets* offsets,
 323           int orig_pc_offset,
 324           DebugInformationRecorder *recorder,
 325           Dependencies* dependencies,
 326           CodeBuffer *code_buffer,
 327           int frame_size,
 328           OopMapSet* oop_maps,
 329           ExceptionHandlerTable* handler_table,
 330           ImplicitExceptionTable* nul_chk_table,
 331           AbstractCompiler* compiler,
 332           CompLevel comp_level
 333 #if INCLUDE_JVMCI
 334           , char* speculations = nullptr,
 335           int speculations_len = 0,
 336           JVMCINMethodData* jvmci_data = nullptr
 337 #endif
 338           );
 339 
 340   // helper methods
 341   void* operator new(size_t size, int nmethod_size, int comp_level) throw();
 342 
 343   // For method handle intrinsics: Try MethodNonProfiled, MethodProfiled and NonNMethod.
 344   // Attention: Only allow NonNMethod space for special nmethods which don't need to be
 345   // findable by nmethod iterators! In particular, they must not contain oops!
 346   void* operator new(size_t size, int nmethod_size, bool allow_NonNMethod_space) throw();
 347 
 348   const char* reloc_string_for(u_char* begin, u_char* end);
 349 
 350   bool try_transition(signed char new_state);
 351 
 352   // Returns true if this thread changed the state of the nmethod or
 353   // false if another thread performed the transition.
 354   bool make_entrant() { Unimplemented(); return false; }
 355   void inc_decompile_count();
 356 
 357   // Inform external interfaces that a compiled method has been unloaded
 358   void post_compiled_method_unload();
 359 
 360   PcDesc* find_pc_desc(address pc, bool approximate) {
 361     if (_pc_desc_container == nullptr) return nullptr; // native method
 362     return _pc_desc_container->find_pc_desc(pc, approximate, code_begin(), scopes_pcs_begin(), scopes_pcs_end());
 363   }
 364 
 365   // STW two-phase nmethod root processing helpers.
 366   //
 367   // When determining liveness of a given nmethod to do code cache unloading,
 368   // some collectors need to do different things depending on whether the nmethods
 369   // need to absolutely be kept alive during root processing; "strong"ly reachable
 370   // nmethods are known to be kept alive at root processing, but the liveness of
 371   // "weak"ly reachable ones is to be determined later.
 372   //
 373   // We want to allow strong and weak processing of nmethods by different threads
 374   // at the same time without heavy synchronization. Additional constraints are
 375   // to make sure that every nmethod is processed a minimal amount of time, and
 376   // nmethods themselves are always iterated at most once at a particular time.
 377   //
 378   // Note that strong processing work must be a superset of weak processing work
 379   // for this code to work.
 380   //
 381   // We store state and claim information in the _oops_do_mark_link member, using
 382   // the two LSBs for the state and the remaining upper bits for linking together
 383   // nmethods that were already visited.
 384   // The last element is self-looped, i.e. points to itself to avoid some special
 385   // "end-of-list" sentinel value.
 386   //
 387   // _oops_do_mark_link special values:
 388   //
 389   //   _oops_do_mark_link == nullptr: the nmethod has not been visited at all yet, i.e.
 390   //      is Unclaimed.
 391   //
 392   // For other values, its lowest two bits indicate the following states of the nmethod:
 393   //
 394   //   weak_request (WR): the nmethod has been claimed by a thread for weak processing
 395   //   weak_done (WD): weak processing has been completed for this nmethod.
 396   //   strong_request (SR): the nmethod has been found to need strong processing while
 397   //       being weak processed.
 398   //   strong_done (SD): strong processing has been completed for this nmethod .
 399   //
 400   // The following shows the _only_ possible progressions of the _oops_do_mark_link
 401   // pointer.
 402   //
 403   // Given
 404   //   N as the nmethod
 405   //   X the current next value of _oops_do_mark_link
 406   //
 407   // Unclaimed (C)-> N|WR (C)-> X|WD: the nmethod has been processed weakly by
 408   //   a single thread.
 409   // Unclaimed (C)-> N|WR (C)-> X|WD (O)-> X|SD: after weak processing has been
 410   //   completed (as above) another thread found that the nmethod needs strong
 411   //   processing after all.
 412   // Unclaimed (C)-> N|WR (O)-> N|SR (C)-> X|SD: during weak processing another
 413   //   thread finds that the nmethod needs strong processing, marks it as such and
 414   //   terminates. The original thread completes strong processing.
 415   // Unclaimed (C)-> N|SD (C)-> X|SD: the nmethod has been processed strongly from
 416   //   the beginning by a single thread.
 417   //
 418   // "|" describes the concatenation of bits in _oops_do_mark_link.
 419   //
 420   // The diagram also describes the threads responsible for changing the nmethod to
 421   // the next state by marking the _transition_ with (C) and (O), which mean "current"
 422   // and "other" thread respectively.
 423   //
 424 
 425   // States used for claiming nmethods during root processing.
 426   static const uint claim_weak_request_tag = 0;
 427   static const uint claim_weak_done_tag = 1;
 428   static const uint claim_strong_request_tag = 2;
 429   static const uint claim_strong_done_tag = 3;
 430 
 431   static oops_do_mark_link* mark_link(nmethod* nm, uint tag) {
 432     assert(tag <= claim_strong_done_tag, "invalid tag %u", tag);
 433     assert(is_aligned(nm, 4), "nmethod pointer must have zero lower two LSB");
 434     return (oops_do_mark_link*)(((uintptr_t)nm & ~0x3) | tag);
 435   }
 436 
 437   static uint extract_state(oops_do_mark_link* link) {
 438     return (uint)((uintptr_t)link & 0x3);
 439   }
 440 
 441   static nmethod* extract_nmethod(oops_do_mark_link* link) {
 442     return (nmethod*)((uintptr_t)link & ~0x3);
 443   }
 444 
 445   void oops_do_log_change(const char* state);
 446 
 447   static bool oops_do_has_weak_request(oops_do_mark_link* next) {
 448     return extract_state(next) == claim_weak_request_tag;
 449   }
 450 
 451   static bool oops_do_has_any_strong_state(oops_do_mark_link* next) {
 452     return extract_state(next) >= claim_strong_request_tag;
 453   }
 454 
 455   // Attempt Unclaimed -> N|WR transition. Returns true if successful.
 456   bool oops_do_try_claim_weak_request();
 457 
 458   // Attempt Unclaimed -> N|SD transition. Returns the current link.
 459   oops_do_mark_link* oops_do_try_claim_strong_done();
 460   // Attempt N|WR -> X|WD transition. Returns nullptr if successful, X otherwise.
 461   nmethod* oops_do_try_add_to_list_as_weak_done();
 462 
 463   // Attempt X|WD -> N|SR transition. Returns the current link.
 464   oops_do_mark_link* oops_do_try_add_strong_request(oops_do_mark_link* next);
 465   // Attempt X|WD -> X|SD transition. Returns true if successful.
 466   bool oops_do_try_claim_weak_done_as_strong_done(oops_do_mark_link* next);
 467 
 468   // Do the N|SD -> X|SD transition.
 469   void oops_do_add_to_list_as_strong_done();
 470 
 471   // Sets this nmethod as strongly claimed (as part of N|SD -> X|SD and N|SR -> X|SD
 472   // transitions).
 473   void oops_do_set_strong_done(nmethod* old_head);
 474 
 475 public:
 476   // create nmethod with entry_bci
 477   static nmethod* new_nmethod(const methodHandle& method,
 478                               int compile_id,
 479                               int entry_bci,
 480                               CodeOffsets* offsets,
 481                               int orig_pc_offset,
 482                               DebugInformationRecorder* recorder,
 483                               Dependencies* dependencies,
 484                               CodeBuffer *code_buffer,
 485                               int frame_size,
 486                               OopMapSet* oop_maps,
 487                               ExceptionHandlerTable* handler_table,
 488                               ImplicitExceptionTable* nul_chk_table,
 489                               AbstractCompiler* compiler,
 490                               CompLevel comp_level
 491 #if INCLUDE_JVMCI
 492                               , char* speculations = nullptr,
 493                               int speculations_len = 0,
 494                               JVMCINMethodData* jvmci_data = nullptr
 495 #endif
 496   );
 497 
 498   static nmethod* new_native_nmethod(const methodHandle& method,
 499                                      int compile_id,
 500                                      CodeBuffer *code_buffer,
 501                                      int vep_offset,
 502                                      int frame_complete,
 503                                      int frame_size,
 504                                      ByteSize receiver_sp_offset,
 505                                      ByteSize basic_lock_sp_offset,
 506                                      OopMapSet* oop_maps,
 507                                      int exception_handler = -1);
 508 
 509   Method* method       () const { return _method; }
 510   bool is_native_method() const { return _method != nullptr && _method->is_native(); }
 511   bool is_java_method  () const { return _method != nullptr && !_method->is_native(); }
 512   bool is_osr_method   () const { return _entry_bci != InvocationEntryBci; }
 513 
 514   // Compiler task identification.  Note that all OSR methods
 515   // are numbered in an independent sequence if CICountOSR is true,
 516   // and native method wrappers are also numbered independently if
 517   // CICountNative is true.
 518   int compile_id() const { return _compile_id; }
 519   const char* compile_kind() const;
 520 
 521   inline bool  is_compiled_by_c1   () const { return _compiler_type == compiler_c1; }
 522   inline bool  is_compiled_by_c2   () const { return _compiler_type == compiler_c2; }
 523   inline bool  is_compiled_by_jvmci() const { return _compiler_type == compiler_jvmci; }
 524   CompilerType compiler_type       () const { return _compiler_type; }
 525   const char*  compiler_name       () const;
 526 
 527   // boundaries for different parts
 528   address consts_begin          () const { return           content_begin(); }
 529   address consts_end            () const { return           code_begin()   ; }
 530   address insts_begin           () const { return           code_begin()   ; }
 531   address insts_end             () const { return           header_begin() + _stub_offset             ; }
 532   address stub_begin            () const { return           header_begin() + _stub_offset             ; }
 533   address stub_end              () const { return           data_begin()   ; }
 534   address exception_begin       () const { return           header_begin() + _exception_offset        ; }
 535   address deopt_handler_begin   () const { return           header_begin() + _deopt_handler_offset    ; }
 536   address deopt_mh_handler_begin() const { return           header_begin() + _deopt_mh_handler_offset ; }
 537   address unwind_handler_begin  () const { return _unwind_handler_offset != -1 ? (insts_end() - _unwind_handler_offset) : nullptr; }
 538 
 539   // mutable data
 540   oop*    oops_begin            () const { return (oop*)        data_begin(); }
 541   oop*    oops_end              () const { return (oop*)       (data_begin() + _metadata_offset)      ; }
 542   Metadata** metadata_begin     () const { return (Metadata**) (data_begin() + _metadata_offset)      ; }
 543 #if INCLUDE_JVMCI
 544   Metadata** metadata_end       () const { return (Metadata**) (data_begin() + _jvmci_data_offset)    ; }
 545   address jvmci_data_begin      () const { return               data_begin() + _jvmci_data_offset     ; }
 546   address jvmci_data_end        () const { return               data_end(); }
 547 #else
 548   Metadata** metadata_end       () const { return (Metadata**)  data_end(); }
 549 #endif
 550 
 551   // immutable data
 552   address immutable_data_begin  () const { return           _immutable_data; }
 553   address immutable_data_end    () const { return           _immutable_data + _immutable_data_size ; }
 554   address dependencies_begin    () const { return           _immutable_data; }
 555   address dependencies_end      () const { return           _immutable_data + _nul_chk_table_offset; }
 556   address nul_chk_table_begin   () const { return           _immutable_data + _nul_chk_table_offset; }
 557   address nul_chk_table_end     () const { return           _immutable_data + _handler_table_offset; }
 558   address handler_table_begin   () const { return           _immutable_data + _handler_table_offset; }
 559   address handler_table_end     () const { return           _immutable_data + _scopes_pcs_offset   ; }
 560   PcDesc* scopes_pcs_begin      () const { return (PcDesc*)(_immutable_data + _scopes_pcs_offset)  ; }
 561   PcDesc* scopes_pcs_end        () const { return (PcDesc*)(_immutable_data + _scopes_data_offset) ; }
 562   address scopes_data_begin     () const { return           _immutable_data + _scopes_data_offset  ; }
 563 
 564 #if INCLUDE_JVMCI
 565   address scopes_data_end       () const { return           _immutable_data + _speculations_offset ; }
 566   address speculations_begin    () const { return           _immutable_data + _speculations_offset ; }
 567   address speculations_end      () const { return            immutable_data_end(); }
 568 #else
 569   address scopes_data_end       () const { return            immutable_data_end(); }
 570 #endif
 571 
 572   // Sizes
 573   int immutable_data_size() const { return _immutable_data_size; }
 574   int consts_size        () const { return int(          consts_end       () -           consts_begin       ()); }
 575   int insts_size         () const { return int(          insts_end        () -           insts_begin        ()); }
 576   int stub_size          () const { return int(          stub_end         () -           stub_begin         ()); }
 577   int oops_size          () const { return int((address) oops_end         () - (address) oops_begin         ()); }
 578   int metadata_size      () const { return int((address) metadata_end     () - (address) metadata_begin     ()); }
 579   int scopes_data_size   () const { return int(          scopes_data_end  () -           scopes_data_begin  ()); }
 580   int scopes_pcs_size    () const { return int((intptr_t)scopes_pcs_end   () - (intptr_t)scopes_pcs_begin   ()); }
 581   int dependencies_size  () const { return int(          dependencies_end () -           dependencies_begin ()); }
 582   int handler_table_size () const { return int(          handler_table_end() -           handler_table_begin()); }
 583   int nul_chk_table_size () const { return int(          nul_chk_table_end() -           nul_chk_table_begin()); }
 584 #if INCLUDE_JVMCI
 585   int speculations_size  () const { return int(          speculations_end () -           speculations_begin ()); }
 586   int jvmci_data_size    () const { return int(          jvmci_data_end   () -           jvmci_data_begin   ()); }
 587 #endif
 588 
 589   int     oops_count() const { assert(oops_size() % oopSize == 0, "");  return (oops_size() / oopSize) + 1; }
 590   int metadata_count() const { assert(metadata_size() % wordSize == 0, ""); return (metadata_size() / wordSize) + 1; }
 591 
 592   int skipped_instructions_size () const { return _skipped_instructions_size; }
 593   int total_size() const;
 594 
 595   // Containment
 596   bool consts_contains         (address addr) const { return consts_begin       () <= addr && addr < consts_end       (); }
 597   // Returns true if a given address is in the 'insts' section. The method
 598   // insts_contains_inclusive() is end-inclusive.
 599   bool insts_contains          (address addr) const { return insts_begin        () <= addr && addr < insts_end        (); }
 600   bool insts_contains_inclusive(address addr) const { return insts_begin        () <= addr && addr <= insts_end       (); }
 601   bool stub_contains           (address addr) const { return stub_begin         () <= addr && addr < stub_end         (); }
 602   bool oops_contains           (oop*    addr) const { return oops_begin         () <= addr && addr < oops_end         (); }
 603   bool metadata_contains       (Metadata** addr) const { return metadata_begin  () <= addr && addr < metadata_end     (); }
 604   bool scopes_data_contains    (address addr) const { return scopes_data_begin  () <= addr && addr < scopes_data_end  (); }
 605   bool scopes_pcs_contains     (PcDesc* addr) const { return scopes_pcs_begin   () <= addr && addr < scopes_pcs_end   (); }
 606   bool handler_table_contains  (address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
 607   bool nul_chk_table_contains  (address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
 608 
 609   // entry points
 610   address entry_point() const          { return code_begin() + _entry_offset;          } // normal entry point
 611   address verified_entry_point() const { return code_begin() + _verified_entry_offset; } // if klass is correct
 612   address inline_entry_point() const              { return _inline_entry_point; }             // inline type entry point (unpack all inline type args)
 613   address verified_inline_entry_point() const     { return _verified_inline_entry_point; }    // inline type entry point (unpack all inline type args) without class check
 614   address verified_inline_ro_entry_point() const  { return _verified_inline_ro_entry_point; } // inline type entry point (only unpack receiver) without class check
 615 
 616   enum : signed char { not_installed = -1, // in construction, only the owner doing the construction is
 617                                            // allowed to advance state
 618                        in_use        = 0,  // executable nmethod
 619                        not_entrant   = 1   // marked for deoptimization but activations may still exist
 620   };
 621 
 622   // flag accessing and manipulation
 623   bool is_not_installed() const        { return _state == not_installed; }
 624   bool is_in_use() const               { return _state <= in_use; }
 625   bool is_not_entrant() const          { return _state == not_entrant; }
 626   int  get_state() const               { return _state; }
 627 
 628   void clear_unloading_state();
 629   // Heuristically deduce an nmethod isn't worth keeping around
 630   bool is_cold();
 631   bool is_unloading();
 632   void do_unloading(bool unloading_occurred);
 633 
 634   bool make_in_use() {
 635     return try_transition(in_use);
 636   }
 637   // Make the nmethod non entrant. The nmethod will continue to be
 638   // alive.  It is used when an uncommon trap happens.  Returns true
 639   // if this thread changed the state of the nmethod or false if
 640   // another thread performed the transition.
 641   bool  make_not_entrant();
 642   bool  make_not_used()    { return make_not_entrant(); }
 643 
 644   bool  is_marked_for_deoptimization() const { return deoptimization_status() != not_marked; }
 645   bool  has_been_deoptimized() const { return deoptimization_status() == deoptimize_done; }
 646   void  set_deoptimized_done();
 647 
 648   bool update_recompile_counts() const {
 649     // Update recompile counts when either the update is explicitly requested (deoptimize)
 650     // or the nmethod is not marked for deoptimization at all (not_marked).
 651     // The latter happens during uncommon traps when deoptimized nmethod is made not entrant.
 652     DeoptimizationStatus status = deoptimization_status();
 653     return status != deoptimize_noupdate && status != deoptimize_done;
 654   }
 655 
 656   // tells whether frames described by this nmethod can be deoptimized
 657   // note: native wrappers cannot be deoptimized.
 658   bool can_be_deoptimized() const { return is_java_method(); }
 659 
 660   bool has_dependencies()                         { return dependencies_size() != 0; }
 661   void print_dependencies_on(outputStream* out) PRODUCT_RETURN;
 662   void flush_dependencies();
 663 
 664   template<typename T>
 665   T* gc_data() const                              { return reinterpret_cast<T*>(_gc_data); }
 666   template<typename T>
 667   void set_gc_data(T* gc_data)                    { _gc_data = reinterpret_cast<void*>(gc_data); }
 668 
 669   bool  has_unsafe_access() const                 { return _has_unsafe_access; }
 670   void  set_has_unsafe_access(bool z)             { _has_unsafe_access = z; }
 671 
 672   bool  has_monitors() const                      { return _has_monitors; }
 673   void  set_has_monitors(bool z)                  { _has_monitors = z; }
 674 
 675   bool  has_method_handle_invokes() const         { return _has_method_handle_invokes; }
 676   void  set_has_method_handle_invokes(bool z)     { _has_method_handle_invokes = z; }
 677 
 678   bool  has_wide_vectors() const                  { return _has_wide_vectors; }
 679   void  set_has_wide_vectors(bool z)              { _has_wide_vectors = z; }
 680 
 681   bool  needs_stack_repair() const {
 682     if (is_compiled_by_c1()) {
 683       return method()->c1_needs_stack_repair();
 684     } else if (is_compiled_by_c2()) {
 685       return method()->c2_needs_stack_repair();
 686     } else {
 687       return false;
 688     }
 689   }
 690 
 691   bool  has_flushed_dependencies() const          { return _has_flushed_dependencies; }
 692   void  set_has_flushed_dependencies(bool z)      {
 693     assert(!has_flushed_dependencies(), "should only happen once");
 694     _has_flushed_dependencies = z;
 695   }
 696 
 697   bool  is_unlinked() const                       { return _is_unlinked; }
 698   void  set_is_unlinked()                         {
 699      assert(!_is_unlinked, "already unlinked");
 700       _is_unlinked = true;
 701   }
 702 
 703   int   comp_level() const                        { return _comp_level; }
 704 
 705   // Support for oops in scopes and relocs:
 706   // Note: index 0 is reserved for null.
 707   oop   oop_at(int index) const;
 708   oop   oop_at_phantom(int index) const; // phantom reference
 709   oop*  oop_addr_at(int index) const {  // for GC
 710     // relocation indexes are biased by 1 (because 0 is reserved)
 711     assert(index > 0 && index <= oops_count(), "must be a valid non-zero index");
 712     return &oops_begin()[index - 1];
 713   }
 714 
 715   // Support for meta data in scopes and relocs:
 716   // Note: index 0 is reserved for null.
 717   Metadata*   metadata_at(int index) const      { return index == 0 ? nullptr: *metadata_addr_at(index); }
 718   Metadata**  metadata_addr_at(int index) const {  // for GC
 719     // relocation indexes are biased by 1 (because 0 is reserved)
 720     assert(index > 0 && index <= metadata_count(), "must be a valid non-zero index");
 721     return &metadata_begin()[index - 1];
 722   }
 723 
 724   void copy_values(GrowableArray<jobject>* oops);
 725   void copy_values(GrowableArray<Metadata*>* metadata);
 726 
 727   // Relocation support
 728 private:
 729   void fix_oop_relocations(address begin, address end, bool initialize_immediates);
 730   inline void initialize_immediate_oop(oop* dest, jobject handle);
 731 
 732 protected:
 733   address oops_reloc_begin() const;
 734 
 735 public:
 736   void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
 737   void fix_oop_relocations()                           { fix_oop_relocations(nullptr, nullptr, false); }
 738 
 739   bool is_at_poll_return(address pc);
 740   bool is_at_poll_or_poll_return(address pc);
 741 
 742 protected:
 743   // Exception cache support
 744   // Note: _exception_cache may be read and cleaned concurrently.
 745   ExceptionCache* exception_cache() const         { return _exception_cache; }
 746   ExceptionCache* exception_cache_acquire() const;
 747 
 748 public:
 749   address handler_for_exception_and_pc(Handle exception, address pc);
 750   void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
 751   void clean_exception_cache();
 752 
 753   void add_exception_cache_entry(ExceptionCache* new_entry);
 754   ExceptionCache* exception_cache_entry_for_exception(Handle exception);
 755 
 756 
 757   // MethodHandle
 758   bool is_method_handle_return(address return_pc);
 759   // Deopt
 760   // Return true is the PC is one would expect if the frame is being deopted.
 761   inline bool is_deopt_pc(address pc);
 762   inline bool is_deopt_mh_entry(address pc);
 763   inline bool is_deopt_entry(address pc);
 764 
 765   // Accessor/mutator for the original pc of a frame before a frame was deopted.
 766   address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
 767   void    set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
 768 
 769   const char* state() const;
 770 
 771   bool inlinecache_check_contains(address addr) const {
 772     return (addr >= code_begin() && addr < verified_entry_point());
 773   }
 774 
 775   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f);
 776 
 777   // implicit exceptions support
 778   address continuation_for_implicit_div0_exception(address pc) { return continuation_for_implicit_exception(pc, true); }
 779   address continuation_for_implicit_null_exception(address pc) { return continuation_for_implicit_exception(pc, false); }
 780 
 781   // Inline cache support for class unloading and nmethod unloading
 782  private:
 783   void cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all);
 784 
 785   address continuation_for_implicit_exception(address pc, bool for_div0_check);
 786 
 787  public:
 788   // Serial version used by whitebox test
 789   void cleanup_inline_caches_whitebox();
 790 
 791   void clear_inline_caches();
 792 
 793   // Execute nmethod barrier code, as if entering through nmethod call.
 794   void run_nmethod_entry_barrier();
 795 
 796   void verify_oop_relocations();
 797 
 798   bool has_evol_metadata();
 799 
 800   Method* attached_method(address call_pc);
 801   Method* attached_method_before_pc(address pc);
 802 
 803   // GC unloading support
 804   // Cleans unloaded klasses and unloaded nmethods in inline caches
 805 
 806   void unload_nmethod_caches(bool class_unloading_occurred);
 807 
 808   void unlink_from_method();
 809 
 810   // On-stack replacement support
 811   int      osr_entry_bci()    const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
 812   address  osr_entry()        const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
 813   nmethod* osr_link()         const { return _osr_link; }
 814   void     set_osr_link(nmethod *n) { _osr_link = n; }
 815   void     invalidate_osr_method();
 816 
 817   int num_stack_arg_slots(bool rounded = true) const {
 818     return rounded ? align_up(_num_stack_arg_slots, 2) : _num_stack_arg_slots;
 819   }
 820 
 821   // Verify calls to dead methods have been cleaned.
 822   void verify_clean_inline_caches();
 823 
 824   // Unlink this nmethod from the system
 825   void unlink();
 826 
 827   // Deallocate this nmethod - called by the GC
 828   void purge(bool unregister_nmethod);
 829 
 830   // See comment at definition of _last_seen_on_stack
 831   void mark_as_maybe_on_stack();
 832   bool is_maybe_on_stack();
 833 
 834   // Evolution support. We make old (discarded) compiled methods point to new Method*s.
 835   void set_method(Method* method) { _method = method; }
 836 
 837 #if INCLUDE_JVMCI
 838   // Gets the JVMCI name of this nmethod.
 839   const char* jvmci_name();
 840 
 841   // Records the pending failed speculation in the
 842   // JVMCI speculation log associated with this nmethod.
 843   void update_speculation(JavaThread* thread);
 844 
 845   // Gets the data specific to a JVMCI compiled method.
 846   // This returns a non-nullptr value iff this nmethod was
 847   // compiled by the JVMCI compiler.
 848   JVMCINMethodData* jvmci_nmethod_data() const {
 849     return jvmci_data_size() == 0 ? nullptr : (JVMCINMethodData*) jvmci_data_begin();
 850   }
 851 #endif
 852 
 853   void oops_do(OopClosure* f) { oops_do(f, false); }
 854   void oops_do(OopClosure* f, bool allow_dead);
 855 
 856   // All-in-one claiming of nmethods: returns true if the caller successfully claimed that
 857   // nmethod.
 858   bool oops_do_try_claim();
 859 
 860   // Loom support for following nmethods on the stack
 861   void follow_nmethod(OopIterateClosure* cl);
 862 
 863   // Class containing callbacks for the oops_do_process_weak/strong() methods
 864   // below.
 865   class OopsDoProcessor {
 866   public:
 867     // Process the oops of the given nmethod based on whether it has been called
 868     // in a weak or strong processing context, i.e. apply either weak or strong
 869     // work on it.
 870     virtual void do_regular_processing(nmethod* nm) = 0;
 871     // Assuming that the oops of the given nmethod has already been its weak
 872     // processing applied, apply the remaining strong processing part.
 873     virtual void do_remaining_strong_processing(nmethod* nm) = 0;
 874   };
 875 
 876   // The following two methods do the work corresponding to weak/strong nmethod
 877   // processing.
 878   void oops_do_process_weak(OopsDoProcessor* p);
 879   void oops_do_process_strong(OopsDoProcessor* p);
 880 
 881   static void oops_do_marking_prologue();
 882   static void oops_do_marking_epilogue();
 883 
 884  private:
 885   ScopeDesc* scope_desc_in(address begin, address end);
 886 
 887   address* orig_pc_addr(const frame* fr);
 888 
 889   // used by jvmti to track if the load events has been reported
 890   bool  load_reported() const                     { return _load_reported; }
 891   void  set_load_reported()                       { _load_reported = true; }
 892 
 893  public:
 894   // ScopeDesc retrieval operation
 895   PcDesc* pc_desc_at(address pc)   { return find_pc_desc(pc, false); }
 896   // pc_desc_near returns the first PcDesc at or after the given pc.
 897   PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
 898 
 899   // ScopeDesc for an instruction
 900   ScopeDesc* scope_desc_at(address pc);
 901   ScopeDesc* scope_desc_near(address pc);
 902 
 903   // copying of debugging information
 904   void copy_scopes_pcs(PcDesc* pcs, int count);
 905   void copy_scopes_data(address buffer, int size);
 906 
 907   int orig_pc_offset() { return _orig_pc_offset; }
 908 
 909   // Post successful compilation
 910   void post_compiled_method(CompileTask* task);
 911 
 912   // jvmti support:
 913   void post_compiled_method_load_event(JvmtiThreadState* state = nullptr);
 914 
 915   // verify operations
 916   void verify() override;
 917   void verify_scopes();
 918   void verify_interrupt_point(address interrupt_point, bool is_inline_cache);
 919 
 920   // Disassemble this nmethod with additional debug information, e.g. information about blocks.
 921   void decode2(outputStream* st) const;
 922   void print_constant_pool(outputStream* st);
 923 
 924   // Avoid hiding of parent's 'decode(outputStream*)' method.
 925   void decode(outputStream* st) const { decode2(st); } // just delegate here.
 926 
 927   // printing support
 928   void print()                 const override;
 929   void print(outputStream* st) const;
 930   void print_code();
 931 
 932 #if defined(SUPPORT_DATA_STRUCTS)
 933   // print output in opt build for disassembler library
 934   void print_relocations()                        PRODUCT_RETURN;
 935   void print_pcs_on(outputStream* st);
 936   void print_scopes() { print_scopes_on(tty); }
 937   void print_scopes_on(outputStream* st)          PRODUCT_RETURN;
 938   void print_value_on(outputStream* st) const override;
 939   void print_handler_table();
 940   void print_nul_chk_table();
 941   void print_recorded_oop(int log_n, int index);
 942   void print_recorded_oops();
 943   void print_recorded_metadata();
 944 
 945   void print_oops(outputStream* st);     // oops from the underlying CodeBlob.
 946   void print_metadata(outputStream* st); // metadata in metadata pool.
 947 #else
 948   void print_pcs_on(outputStream* st) { return; }
 949 #endif
 950 
 951   void print_calls(outputStream* st)              PRODUCT_RETURN;
 952   static void print_statistics()                  PRODUCT_RETURN;
 953 
 954   void maybe_print_nmethod(const DirectiveSet* directive);
 955   void print_nmethod(bool print_code);
 956 
 957   // need to re-define this from CodeBlob else the overload hides it
 958   void print_on(outputStream* st) const override { CodeBlob::print_on(st); }
 959   void print_on(outputStream* st, const char* msg) const;
 960 
 961   // Logging
 962   void log_identity(xmlStream* log) const;
 963   void log_new_nmethod() const;
 964   void log_state_change() const;
 965 
 966   // Prints block-level comments, including nmethod specific block labels:
 967   void print_block_comment(outputStream* stream, address block_begin) const override {
 968 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 969     print_nmethod_labels(stream, block_begin);
 970     CodeBlob::print_block_comment(stream, block_begin);
 971 #endif
 972   }
 973 
 974   void print_nmethod_labels(outputStream* stream, address block_begin, bool print_section_labels=true) const;
 975   const char* nmethod_section_label(address pos) const;
 976 
 977   // returns whether this nmethod has code comments.
 978   bool has_code_comment(address begin, address end);
 979   // Prints a comment for one native instruction (reloc info, pc desc)
 980   void print_code_comment_on(outputStream* st, int column, address begin, address end);
 981 
 982   // tells if this compiled method is dependent on the given changes,
 983   // and the changes have invalidated it
 984   bool check_dependency_on(DepChange& changes);
 985 
 986   // Fast breakpoint support. Tells if this compiled method is
 987   // dependent on the given method. Returns true if this nmethod
 988   // corresponds to the given method as well.
 989   bool is_dependent_on_method(Method* dependee);
 990 
 991   // JVMTI's GetLocalInstance() support
 992   ByteSize native_receiver_sp_offset() {
 993     assert(is_native_method(), "sanity");
 994     return _native_receiver_sp_offset;
 995   }
 996   ByteSize native_basic_lock_sp_offset() {
 997     assert(is_native_method(), "sanity");
 998     return _native_basic_lock_sp_offset;
 999   }
1000 
1001   // support for code generation
1002   static ByteSize osr_entry_point_offset() { return byte_offset_of(nmethod, _osr_entry_point); }
1003   static ByteSize state_offset()           { return byte_offset_of(nmethod, _state); }
1004 
1005   void metadata_do(MetadataClosure* f);
1006 
1007   address call_instruction_address(address pc) const;
1008 
1009   void make_deoptimized();
1010   void finalize_relocations();
1011 };
1012 
1013 #endif // SHARE_CODE_NMETHOD_HPP