1 /*
   2  * Copyright (c) 2015, 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 #ifndef SHARE_CODE_COMPILEDMETHOD_HPP
  26 #define SHARE_CODE_COMPILEDMETHOD_HPP
  27 
  28 #include "code/codeBlob.hpp"
  29 #include "code/pcDesc.hpp"
  30 #include "oops/metadata.hpp"
  31 
  32 class Dependencies;
  33 class ExceptionHandlerTable;
  34 class ImplicitExceptionTable;
  35 class AbstractCompiler;
  36 class xmlStream;
  37 class CompiledStaticCall;
  38 class NativeCallWrapper;
  39 class ScopeDesc;
  40 class CompiledIC;
  41 class MetadataClosure;
  42 
  43 // This class is used internally by nmethods, to cache
  44 // exception/pc/handler information.
  45 
  46 class ExceptionCache : public CHeapObj<mtCode> {
  47   friend class VMStructs;
  48  private:
  49   enum { cache_size = 16 };
  50   Klass*   _exception_type;
  51   address  _pc[cache_size];
  52   address  _handler[cache_size];
  53   volatile int _count;
  54   ExceptionCache* volatile _next;
  55   ExceptionCache* _purge_list_next;
  56 
  57   inline address pc_at(int index);
  58   void set_pc_at(int index, address a)      { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
  59 
  60   inline address handler_at(int index);
  61   void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
  62 
  63   inline int count();
  64   // increment_count is only called under lock, but there may be concurrent readers.
  65   void increment_count();
  66 
  67  public:
  68 
  69   ExceptionCache(Handle exception, address pc, address handler);
  70 
  71   Klass*    exception_type()                { return _exception_type; }
  72   ExceptionCache* next();
  73   void      set_next(ExceptionCache *ec);
  74   ExceptionCache* purge_list_next()                 { return _purge_list_next; }
  75   void      set_purge_list_next(ExceptionCache *ec) { _purge_list_next = ec; }
  76 
  77   address match(Handle exception, address pc);
  78   bool    match_exception_with_space(Handle exception) ;
  79   address test_address(address addr);
  80   bool    add_address_and_handler(address addr, address handler) ;
  81 };
  82 
  83 class nmethod;
  84 
  85 // cache pc descs found in earlier inquiries
  86 class PcDescCache {
  87   friend class VMStructs;
  88  private:
  89   enum { cache_size = 4 };
  90   // The array elements MUST be volatile! Several threads may modify
  91   // and read from the cache concurrently. find_pc_desc_internal has
  92   // returned wrong results. C++ compiler (namely xlC12) may duplicate
  93   // C++ field accesses if the elements are not volatile.
  94   typedef PcDesc* PcDescPtr;
  95   volatile PcDescPtr _pc_descs[cache_size]; // last cache_size pc_descs found
  96  public:
  97   PcDescCache() { debug_only(_pc_descs[0] = NULL); }
  98   void    reset_to(PcDesc* initial_pc_desc);
  99   PcDesc* find_pc_desc(int pc_offset, bool approximate);
 100   void    add_pc_desc(PcDesc* pc_desc);
 101   PcDesc* last_pc_desc() { return _pc_descs[0]; }
 102 };
 103 
 104 class PcDescSearch {
 105 private:
 106   address _code_begin;
 107   PcDesc* _lower;
 108   PcDesc* _upper;
 109 public:
 110   PcDescSearch(address code, PcDesc* lower, PcDesc* upper) :
 111     _code_begin(code), _lower(lower), _upper(upper)
 112   {
 113   }
 114 
 115   address code_begin() const { return _code_begin; }
 116   PcDesc* scopes_pcs_begin() const { return _lower; }
 117   PcDesc* scopes_pcs_end() const { return _upper; }
 118 };
 119 
 120 class PcDescContainer {
 121 private:
 122   PcDescCache _pc_desc_cache;
 123 public:
 124   PcDescContainer() {}
 125 
 126   PcDesc* find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search);
 127   void    reset_to(PcDesc* initial_pc_desc) { _pc_desc_cache.reset_to(initial_pc_desc); }
 128 
 129   PcDesc* find_pc_desc(address pc, bool approximate, const PcDescSearch& search) {
 130     address base_address = search.code_begin();
 131     PcDesc* desc = _pc_desc_cache.last_pc_desc();
 132     if (desc != NULL && desc->pc_offset() == pc - base_address) {
 133       return desc;
 134     }
 135     return find_pc_desc_internal(pc, approximate, search);
 136   }
 137 };
 138 
 139 
 140 class CompiledMethod : public CodeBlob {
 141   friend class VMStructs;
 142   friend class NMethodSweeper;
 143 
 144   void init_defaults();
 145 protected:
 146   enum MarkForDeoptimizationStatus {
 147     not_marked,
 148     deoptimize,
 149     deoptimize_noupdate
 150   };
 151 
 152   MarkForDeoptimizationStatus _mark_for_deoptimization_status; // Used for stack deoptimization
 153 
 154   bool _is_far_code; // Code is far from CodeCache.
 155                      // Have to use far call instructions to call it from code in CodeCache.
 156 
 157   // set during construction
 158   unsigned int _has_unsafe_access:1;         // May fault due to unsafe access.
 159   unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes?
 160   unsigned int _lazy_critical_native:1;      // Lazy JNI critical native
 161   unsigned int _has_wide_vectors:1;          // Preserve wide vectors at safepoints
 162 
 163   Method*   _method;
 164   address _scopes_data_begin;
 165   // All deoptee's will resume execution at this location described by
 166   // this address.
 167   address _deopt_handler_begin;
 168   // All deoptee's at a MethodHandle call site will resume execution
 169   // at this location described by this offset.
 170   address _deopt_mh_handler_begin;
 171 
 172   PcDescContainer _pc_desc_container;
 173   ExceptionCache * volatile _exception_cache;
 174 
 175   void* _gc_data;
 176 
 177   virtual void flush() = 0;
 178 protected:
 179   CompiledMethod(Method* method, const char* name, CompilerType type, const CodeBlobLayout& layout, int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps, bool caller_must_gc_arguments);
 180   CompiledMethod(Method* method, const char* name, CompilerType type, int size, int header_size, CodeBuffer* cb, int frame_complete_offset, int frame_size, OopMapSet* oop_maps, bool caller_must_gc_arguments);
 181 
 182 public:
 183   // Only used by unit test.
 184   CompiledMethod() {}
 185 
 186   virtual bool is_compiled() const                { return true; }
 187 
 188   template<typename T>
 189   T* gc_data() const                              { return reinterpret_cast<T*>(_gc_data); }
 190   template<typename T>
 191   void set_gc_data(T* gc_data)                    { _gc_data = reinterpret_cast<void*>(gc_data); }
 192 
 193   bool  has_unsafe_access() const                 { return _has_unsafe_access; }
 194   void  set_has_unsafe_access(bool z)             { _has_unsafe_access = z; }
 195 
 196   bool  has_method_handle_invokes() const         { return _has_method_handle_invokes; }
 197   void  set_has_method_handle_invokes(bool z)     { _has_method_handle_invokes = z; }
 198 
 199   bool  is_lazy_critical_native() const           { return _lazy_critical_native; }
 200   void  set_lazy_critical_native(bool z)          { _lazy_critical_native = z; }
 201 
 202   bool  has_wide_vectors() const                  { return _has_wide_vectors; }
 203   void  set_has_wide_vectors(bool z)              { _has_wide_vectors = z; }
 204 
 205   enum { not_installed = -1, // in construction, only the owner doing the construction is
 206                              // allowed to advance state
 207          in_use        = 0,  // executable nmethod
 208          not_used      = 1,  // not entrant, but revivable
 209          not_entrant   = 2,  // marked for deoptimization but activations may still exist,
 210                              // will be transformed to zombie when all activations are gone
 211          unloaded      = 3,  // there should be no activations, should not be called, will be
 212                              // transformed to zombie by the sweeper, when not "locked in vm".
 213          zombie        = 4   // no activations exist, nmethod is ready for purge
 214   };
 215 
 216   virtual bool  is_in_use() const = 0;
 217   virtual int   comp_level() const = 0;
 218   virtual int   compile_id() const = 0;
 219 
 220   virtual address verified_entry_point() const = 0;
 221   virtual void log_identity(xmlStream* log) const = 0;
 222   virtual void log_state_change() const = 0;
 223   virtual bool make_not_used() = 0;
 224   virtual bool make_not_entrant() = 0;
 225   virtual bool make_entrant() = 0;
 226   virtual address entry_point() const = 0;
 227   virtual bool make_zombie() = 0;
 228   virtual bool is_osr_method() const = 0;
 229   virtual int osr_entry_bci() const = 0;
 230   Method* method() const                          { return _method; }
 231   virtual void print_pcs() = 0;
 232   bool is_native_method() const { return _method != NULL && _method->is_native(); }
 233   bool is_java_method() const { return _method != NULL && !_method->is_native(); }
 234 
 235   // ScopeDesc retrieval operation
 236   PcDesc* pc_desc_at(address pc)   { return find_pc_desc(pc, false); }
 237   // pc_desc_near returns the first PcDesc at or after the given pc.
 238   PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
 239 
 240   // ScopeDesc for an instruction
 241   ScopeDesc* scope_desc_at(address pc);
 242   ScopeDesc* scope_desc_near(address pc);
 243 
 244   bool is_at_poll_return(address pc);
 245   bool is_at_poll_or_poll_return(address pc);
 246 
 247   bool  is_marked_for_deoptimization() const { return _mark_for_deoptimization_status != not_marked; }
 248   void  mark_for_deoptimization(bool inc_recompile_counts = true);
 249 
 250   bool update_recompile_counts() const {
 251     // Update recompile counts when either the update is explicitly requested (deoptimize)
 252     // or the nmethod is not marked for deoptimization at all (not_marked).
 253     // The latter happens during uncommon traps when deoptimized nmethod is made not entrant.
 254     return _mark_for_deoptimization_status != deoptimize_noupdate;
 255   }
 256 
 257   static bool nmethod_access_is_safe(nmethod* nm);
 258 
 259   // tells whether frames described by this nmethod can be deoptimized
 260   // note: native wrappers cannot be deoptimized.
 261   bool can_be_deoptimized() const { return is_java_method(); }
 262 
 263   virtual oop oop_at(int index) const = 0;
 264   virtual Metadata* metadata_at(int index) const = 0;
 265 
 266   address scopes_data_begin() const { return _scopes_data_begin; }
 267   virtual address scopes_data_end() const = 0;
 268   int scopes_data_size() const { return scopes_data_end() - scopes_data_begin(); }
 269 
 270   virtual PcDesc* scopes_pcs_begin() const = 0;
 271   virtual PcDesc* scopes_pcs_end() const = 0;
 272   int scopes_pcs_size() const { return (intptr_t) scopes_pcs_end() - (intptr_t) scopes_pcs_begin(); }
 273 
 274   address insts_begin() const { return code_begin(); }
 275   address insts_end() const { return stub_begin(); }
 276   // Returns true if a given address is in the 'insts' section. The method
 277   // insts_contains_inclusive() is end-inclusive.
 278   bool insts_contains(address addr) const { return insts_begin() <= addr && addr < insts_end(); }
 279   bool insts_contains_inclusive(address addr) const { return insts_begin() <= addr && addr <= insts_end(); }
 280 
 281   int insts_size() const { return insts_end() - insts_begin(); }
 282 
 283   virtual address consts_begin() const = 0;
 284   virtual address consts_end() const = 0;
 285   bool consts_contains(address addr) const { return consts_begin() <= addr && addr < consts_end(); }
 286   int consts_size() const { return consts_end() - consts_begin(); }
 287 
 288   virtual address stub_begin() const = 0;
 289   virtual address stub_end() const = 0;
 290   bool stub_contains(address addr) const { return stub_begin() <= addr && addr < stub_end(); }
 291   int stub_size() const { return stub_end() - stub_begin(); }
 292 
 293   virtual address handler_table_begin() const = 0;
 294   virtual address handler_table_end() const = 0;
 295   bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
 296   int handler_table_size() const { return handler_table_end() - handler_table_begin(); }
 297 
 298   virtual address exception_begin() const = 0;
 299 
 300   virtual address nul_chk_table_begin() const = 0;
 301   virtual address nul_chk_table_end() const = 0;
 302   bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
 303   int nul_chk_table_size() const { return nul_chk_table_end() - nul_chk_table_begin(); }
 304 
 305   virtual oop* oop_addr_at(int index) const = 0;
 306   virtual Metadata** metadata_addr_at(int index) const = 0;
 307   virtual void    set_original_pc(const frame* fr, address pc) = 0;
 308 
 309 protected:
 310   // Exception cache support
 311   // Note: _exception_cache may be read and cleaned concurrently.
 312   ExceptionCache* exception_cache() const         { return _exception_cache; }
 313   ExceptionCache* exception_cache_acquire() const;
 314   void set_exception_cache(ExceptionCache *ec)    { _exception_cache = ec; }
 315 
 316 public:
 317   address handler_for_exception_and_pc(Handle exception, address pc);
 318   void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
 319   void clean_exception_cache();
 320 
 321   void add_exception_cache_entry(ExceptionCache* new_entry);
 322   ExceptionCache* exception_cache_entry_for_exception(Handle exception);
 323 
 324   // MethodHandle
 325   bool is_method_handle_return(address return_pc);
 326   address deopt_mh_handler_begin() const  { return _deopt_mh_handler_begin; }
 327 
 328   address deopt_handler_begin() const { return _deopt_handler_begin; }
 329   virtual address get_original_pc(const frame* fr) = 0;
 330   // Deopt
 331   // Return true is the PC is one would expect if the frame is being deopted.
 332   inline bool is_deopt_pc(address pc);
 333   bool is_deopt_mh_entry(address pc) { return pc == deopt_mh_handler_begin(); }
 334   inline bool is_deopt_entry(address pc);
 335 
 336   virtual bool can_convert_to_zombie() = 0;
 337   virtual const char* compile_kind() const = 0;
 338   virtual int get_state() const = 0;
 339 
 340   const char* state() const;
 341 
 342   bool is_far_code() const { return _is_far_code; }
 343 
 344   bool inlinecache_check_contains(address addr) const {
 345     return (addr >= code_begin() && addr < verified_entry_point());
 346   }
 347 
 348   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f);
 349 
 350   // implicit exceptions support
 351   address continuation_for_implicit_div0_exception(address pc) { return continuation_for_implicit_exception(pc, true); }
 352   address continuation_for_implicit_null_exception(address pc) { return continuation_for_implicit_exception(pc, false); }
 353 
 354   static address get_deopt_original_pc(const frame* fr);
 355 
 356   // Inline cache support for class unloading and nmethod unloading
 357  private:
 358   bool cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all);
 359 
 360   address continuation_for_implicit_exception(address pc, bool for_div0_check);
 361 
 362  public:
 363   // Serial version used by sweeper and whitebox test
 364   void cleanup_inline_caches(bool clean_all);
 365 
 366   virtual void clear_inline_caches();
 367   void clear_ic_callsites();
 368 
 369   // Verify and count cached icholder relocations.
 370   int  verify_icholder_relocations();
 371   void verify_oop_relocations();
 372 
 373   bool has_evol_metadata();
 374 
 375   // Fast breakpoint support. Tells if this compiled method is
 376   // dependent on the given method. Returns true if this nmethod
 377   // corresponds to the given method as well.
 378   virtual bool is_dependent_on_method(Method* dependee) = 0;
 379 
 380   virtual NativeCallWrapper* call_wrapper_at(address call) const = 0;
 381   virtual NativeCallWrapper* call_wrapper_before(address return_pc) const = 0;
 382   virtual address call_instruction_address(address pc) const = 0;
 383 
 384   virtual CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) const = 0;
 385   virtual CompiledStaticCall* compiledStaticCall_at(address addr) const = 0;
 386   virtual CompiledStaticCall* compiledStaticCall_before(address addr) const = 0;
 387 
 388   Method* attached_method(address call_pc);
 389   Method* attached_method_before_pc(address pc);
 390 
 391   virtual void metadata_do(MetadataClosure* f) = 0;
 392 
 393   // GC support
 394  protected:
 395   address oops_reloc_begin() const;
 396 
 397  private:
 398   bool static clean_ic_if_metadata_is_dead(CompiledIC *ic);
 399 
 400  public:
 401   // GC unloading support
 402   // Cleans unloaded klasses and unloaded nmethods in inline caches
 403 
 404   virtual bool is_unloading() = 0;
 405 
 406   bool unload_nmethod_caches(bool class_unloading_occurred);
 407   virtual void do_unloading(bool unloading_occurred) = 0;
 408 
 409 private:
 410   PcDesc* find_pc_desc(address pc, bool approximate) {
 411     return _pc_desc_container.find_pc_desc(pc, approximate, PcDescSearch(code_begin(), scopes_pcs_begin(), scopes_pcs_end()));
 412   }
 413 };
 414 
 415 #endif // SHARE_CODE_COMPILEDMETHOD_HPP