1 /*
   2  * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_CODE_COMPILEDMETHOD_HPP
  26 #define SHARE_VM_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 
  40 // This class is used internally by nmethods, to cache
  41 // exception/pc/handler information.
  42 
  43 class ExceptionCache : public CHeapObj<mtCode> {
  44   friend class VMStructs;
  45  private:
  46   enum { cache_size = 16 };
  47   Klass*   _exception_type;
  48   address  _pc[cache_size];
  49   address  _handler[cache_size];
  50   volatile int _count;
  51   ExceptionCache* _next;
  52 
  53   inline address pc_at(int index);
  54   void set_pc_at(int index, address a)      { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
  55 
  56   inline address handler_at(int index);
  57   void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
  58 
  59   inline int count();
  60   // increment_count is only called under lock, but there may be concurrent readers.
  61   void increment_count();
  62 
  63  public:
  64 
  65   ExceptionCache(Handle exception, address pc, address handler);
  66 
  67   Klass*    exception_type()                { return _exception_type; }
  68   ExceptionCache* next()                    { return _next; }
  69   void      set_next(ExceptionCache *ec)    { _next = ec; }
  70 
  71   address match(Handle exception, address pc);
  72   bool    match_exception_with_space(Handle exception) ;
  73   address test_address(address addr);
  74   bool    add_address_and_handler(address addr, address handler) ;
  75 };
  76 
  77 class nmethod;
  78 
  79 // cache pc descs found in earlier inquiries
  80 class PcDescCache {
  81   friend class VMStructs;
  82  private:
  83   enum { cache_size = 4 };
  84   // The array elements MUST be volatile! Several threads may modify
  85   // and read from the cache concurrently. find_pc_desc_internal has
  86   // returned wrong results. C++ compiler (namely xlC12) may duplicate
  87   // C++ field accesses if the elements are not volatile.
  88   typedef PcDesc* PcDescPtr;
  89   volatile PcDescPtr _pc_descs[cache_size]; // last cache_size pc_descs found
  90  public:
  91   PcDescCache() { debug_only(_pc_descs[0] = NULL); }
  92   void    reset_to(PcDesc* initial_pc_desc);
  93   PcDesc* find_pc_desc(int pc_offset, bool approximate);
  94   void    add_pc_desc(PcDesc* pc_desc);
  95   PcDesc* last_pc_desc() { return _pc_descs[0]; }
  96 };
  97 
  98 class PcDescSearch {
  99 private:
 100   address _code_begin;
 101   PcDesc* _lower;
 102   PcDesc* _upper;
 103 public:
 104   PcDescSearch(address code, PcDesc* lower, PcDesc* upper) :
 105     _code_begin(code), _lower(lower), _upper(upper)
 106   {
 107   }
 108 
 109   address code_begin() const { return _code_begin; }
 110   PcDesc* scopes_pcs_begin() const { return _lower; }
 111   PcDesc* scopes_pcs_end() const { return _upper; }
 112 };
 113 
 114 class PcDescContainer {
 115 private:
 116   PcDescCache _pc_desc_cache;
 117 public:
 118   PcDescContainer() {}
 119 
 120   PcDesc* find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search);
 121   void    reset_to(PcDesc* initial_pc_desc) { _pc_desc_cache.reset_to(initial_pc_desc); }
 122 
 123   PcDesc* find_pc_desc(address pc, bool approximate, const PcDescSearch& search) {
 124     address base_address = search.code_begin();
 125     PcDesc* desc = _pc_desc_cache.last_pc_desc();
 126     if (desc != NULL && desc->pc_offset() == pc - base_address) {
 127       return desc;
 128     }
 129     return find_pc_desc_internal(pc, approximate, search);
 130   }
 131 };
 132 
 133 
 134 class CompiledMethod : public CodeBlob {
 135   friend class VMStructs;
 136   friend class NMethodSweeper;
 137 
 138   void init_defaults();
 139 protected:
 140   enum MarkForDeoptimizationStatus {
 141     not_marked,
 142     deoptimize,
 143     deoptimize_noupdate
 144   };
 145 
 146   MarkForDeoptimizationStatus _mark_for_deoptimization_status; // Used for stack deoptimization
 147 
 148   bool _is_far_code; // Code is far from CodeCache.
 149                      // Have to use far call instructions to call it from code in CodeCache.
 150   // set during construction
 151   unsigned int _has_unsafe_access:1;         // May fault due to unsafe access.
 152   unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes?
 153   unsigned int _lazy_critical_native:1;      // Lazy JNI critical native
 154   unsigned int _has_wide_vectors:1;          // Preserve wide vectors at safepoints
 155 
 156   Method*   _method;
 157   address _scopes_data_begin;
 158   // All deoptee's will resume execution at this location described by
 159   // this address.
 160   address _deopt_handler_begin;
 161   // All deoptee's at a MethodHandle call site will resume execution
 162   // at this location described by this offset.
 163   address _deopt_mh_handler_begin;
 164 
 165   PcDescContainer _pc_desc_container;
 166   ExceptionCache * volatile _exception_cache;
 167 
 168   virtual void flush() = 0;
 169 protected:
 170   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);
 171   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);
 172 
 173 public:
 174   virtual bool is_compiled() const                { return true; }
 175 
 176   bool  has_unsafe_access() const                 { return _has_unsafe_access; }
 177   void  set_has_unsafe_access(bool z)             { _has_unsafe_access = z; }
 178 
 179   bool  has_method_handle_invokes() const         { return _has_method_handle_invokes; }
 180   void  set_has_method_handle_invokes(bool z)     { _has_method_handle_invokes = z; }
 181 
 182   bool  is_lazy_critical_native() const           { return _lazy_critical_native; }
 183   void  set_lazy_critical_native(bool z)          { _lazy_critical_native = z; }
 184 
 185   bool  has_wide_vectors() const                  { return _has_wide_vectors; }
 186   void  set_has_wide_vectors(bool z)              { _has_wide_vectors = z; }
 187 
 188   enum { not_installed = -1, // in construction, only the owner doing the construction is
 189                              // allowed to advance state
 190          in_use        = 0,  // executable nmethod
 191          not_used      = 1,  // not entrant, but revivable
 192          not_entrant   = 2,  // marked for deoptimization but activations may still exist,
 193                              // will be transformed to zombie when all activations are gone
 194          zombie        = 3,  // no activations exist, nmethod is ready for purge
 195          unloaded      = 4   // there should be no activations, should not be called,
 196                              // will be transformed to zombie immediately
 197   };
 198 
 199   virtual bool  is_in_use() const = 0;
 200   virtual int   comp_level() const = 0;
 201   virtual int   compile_id() const = 0;
 202 
 203   virtual address verified_entry_point() const = 0;
 204   virtual void log_identity(xmlStream* log) const = 0;
 205   virtual void log_state_change() const = 0;
 206   virtual bool make_not_used() = 0;
 207   virtual bool make_not_entrant() = 0;
 208   virtual bool make_entrant() = 0;
 209   virtual address entry_point() const = 0;
 210   virtual bool make_zombie() = 0;
 211   virtual bool is_osr_method() const = 0;
 212   virtual int osr_entry_bci() const = 0;
 213   Method* method() const                          { return _method; }
 214   virtual void print_pcs() = 0;
 215   bool is_native_method() const { return _method != NULL && _method->is_native(); }
 216   bool is_java_method() const { return _method != NULL && !_method->is_native(); }
 217 
 218   // ScopeDesc retrieval operation
 219   PcDesc* pc_desc_at(address pc)   { return find_pc_desc(pc, false); }
 220   // pc_desc_near returns the first PcDesc at or after the given pc.
 221   PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
 222 
 223   // ScopeDesc for an instruction
 224   ScopeDesc* scope_desc_at(address pc);
 225   ScopeDesc* scope_desc_near(address pc);
 226 
 227   bool is_at_poll_return(address pc);
 228   bool is_at_poll_or_poll_return(address pc);
 229 
 230   bool  is_marked_for_deoptimization() const      { return _mark_for_deoptimization_status != not_marked; }
 231   void  mark_for_deoptimization(bool inc_recompile_counts = true) {
 232     _mark_for_deoptimization_status = (inc_recompile_counts ? deoptimize : deoptimize_noupdate);
 233   }
 234   bool update_recompile_counts() const {
 235     // Update recompile counts when either the update is explicitly requested (deoptimize)
 236     // or the nmethod is not marked for deoptimization at all (not_marked).
 237     // The latter happens during uncommon traps when deoptimized nmethod is made not entrant.
 238     return _mark_for_deoptimization_status != deoptimize_noupdate;
 239   }
 240 
 241   static bool nmethod_access_is_safe(nmethod* nm);
 242 
 243   // tells whether frames described by this nmethod can be deoptimized
 244   // note: native wrappers cannot be deoptimized.
 245   bool can_be_deoptimized() const { return is_java_method(); }
 246 
 247   virtual oop oop_at(int index) const = 0;
 248   virtual Metadata* metadata_at(int index) const = 0;
 249 
 250   address scopes_data_begin() const { return _scopes_data_begin; }
 251   virtual address scopes_data_end() const = 0;
 252   int scopes_data_size() const { return scopes_data_end() - scopes_data_begin(); }
 253 
 254   virtual PcDesc* scopes_pcs_begin() const = 0;
 255   virtual PcDesc* scopes_pcs_end() const = 0;
 256   int scopes_pcs_size() const { return (intptr_t) scopes_pcs_end() - (intptr_t) scopes_pcs_begin(); }
 257 
 258   address insts_begin() const { return code_begin(); }
 259   address insts_end() const { return stub_begin(); }
 260   // Returns true if a given address is in the 'insts' section. The method
 261   // insts_contains_inclusive() is end-inclusive.
 262   bool insts_contains(address addr) const { return insts_begin() <= addr && addr < insts_end(); }
 263   bool insts_contains_inclusive(address addr) const { return insts_begin() <= addr && addr <= insts_end(); }
 264 
 265   int insts_size() const { return insts_end() - insts_begin(); }
 266 
 267   virtual address consts_begin() const = 0;
 268   virtual address consts_end() const = 0;
 269   bool consts_contains(address addr) const { return consts_begin() <= addr && addr < consts_end(); }
 270   int consts_size() const { return consts_end() - consts_begin(); }
 271 
 272   virtual address stub_begin() const = 0;
 273   virtual address stub_end() const = 0;
 274   bool stub_contains(address addr) const { return stub_begin() <= addr && addr < stub_end(); }
 275   int stub_size() const { return stub_end() - stub_begin(); }
 276 
 277   virtual address handler_table_begin() const = 0;
 278   virtual address handler_table_end() const = 0;
 279   bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
 280   int handler_table_size() const { return handler_table_end() - handler_table_begin(); }
 281 
 282   virtual address exception_begin() const = 0;
 283 
 284   virtual address nul_chk_table_begin() const = 0;
 285   virtual address nul_chk_table_end() const = 0;
 286   bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
 287   int nul_chk_table_size() const { return nul_chk_table_end() - nul_chk_table_begin(); }
 288 
 289   virtual oop* oop_addr_at(int index) const = 0;
 290   virtual Metadata** metadata_addr_at(int index) const = 0;
 291   virtual void    set_original_pc(const frame* fr, address pc) = 0;
 292 
 293   // Exception cache support
 294   // Note: _exception_cache may be read concurrently. We rely on memory_order_consume here.
 295   ExceptionCache* exception_cache() const         { return _exception_cache; }
 296   void set_exception_cache(ExceptionCache *ec)    { _exception_cache = ec; }
 297   void release_set_exception_cache(ExceptionCache *ec);
 298   address handler_for_exception_and_pc(Handle exception, address pc);
 299   void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
 300   void clean_exception_cache();
 301 
 302   void add_exception_cache_entry(ExceptionCache* new_entry);
 303   ExceptionCache* exception_cache_entry_for_exception(Handle exception);
 304 
 305   // MethodHandle
 306   bool is_method_handle_return(address return_pc);
 307   address deopt_mh_handler_begin() const  { return _deopt_mh_handler_begin; }
 308 
 309   address deopt_handler_begin() const { return _deopt_handler_begin; }
 310   virtual address get_original_pc(const frame* fr) = 0;
 311   // Deopt
 312   // Return true is the PC is one would expect if the frame is being deopted.
 313   inline bool is_deopt_pc(address pc);
 314   bool is_deopt_mh_entry(address pc) { return pc == deopt_mh_handler_begin(); }
 315   inline bool is_deopt_entry(address pc);
 316 
 317   virtual bool can_convert_to_zombie() = 0;
 318   virtual const char* compile_kind() const = 0;
 319   virtual int get_state() const = 0;
 320 
 321   const char* state() const;
 322 
 323   bool is_far_code() const { return _is_far_code; }
 324 
 325   bool inlinecache_check_contains(address addr) const {
 326     return (addr >= code_begin() && addr < verified_entry_point());
 327   }
 328 
 329   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f);
 330 
 331   // implicit exceptions support
 332   virtual address continuation_for_implicit_exception(address pc) { return NULL; }
 333 
 334   static address get_deopt_original_pc(const frame* fr);
 335 
 336   // GC unloading support
 337   // Cleans unloaded klasses and unloaded nmethods in inline caches
 338   bool unload_nmethod_caches(bool parallel, bool class_unloading_occurred);
 339 
 340   // Inline cache support for class unloading and nmethod unloading
 341  private:
 342   bool cleanup_inline_caches_impl(bool parallel, bool unloading_occurred, bool clean_all);
 343  public:
 344   bool cleanup_inline_caches(bool clean_all = false) {
 345     // Serial version used by sweeper and whitebox test
 346     return cleanup_inline_caches_impl(false, false, clean_all);
 347   }
 348 
 349   virtual void clear_inline_caches();
 350   void clear_ic_callsites();
 351 
 352   // Verify and count cached icholder relocations.
 353   int  verify_icholder_relocations();
 354   void verify_oop_relocations();
 355 
 356   virtual bool is_evol_dependent_on(Klass* dependee) = 0;
 357   // Fast breakpoint support. Tells if this compiled method is
 358   // dependent on the given method. Returns true if this nmethod
 359   // corresponds to the given method as well.
 360   virtual bool is_dependent_on_method(Method* dependee) = 0;
 361 
 362   virtual NativeCallWrapper* call_wrapper_at(address call) const = 0;
 363   virtual NativeCallWrapper* call_wrapper_before(address return_pc) const = 0;
 364   virtual address call_instruction_address(address pc) const = 0;
 365 
 366   virtual CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) const = 0;
 367   virtual CompiledStaticCall* compiledStaticCall_at(address addr) const = 0;
 368   virtual CompiledStaticCall* compiledStaticCall_before(address addr) const = 0;
 369 
 370   Method* attached_method(address call_pc);
 371   Method* attached_method_before_pc(address pc);
 372 
 373   virtual void metadata_do(void f(Metadata*)) = 0;
 374 
 375   // GC support
 376 
 377   void set_unloading_next(CompiledMethod* next) { _unloading_next = next; }
 378   CompiledMethod* unloading_next()              { return _unloading_next; }
 379 
 380  protected:
 381   address oops_reloc_begin() const;
 382  private:
 383   void static clean_ic_if_metadata_is_dead(CompiledIC *ic);
 384 
 385   void clean_ic_stubs();
 386 
 387  public:
 388   virtual void do_unloading(BoolObjectClosure* is_alive);
 389   //  The parallel versions are used by G1.
 390   virtual bool do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred);
 391   virtual void do_unloading_parallel_postponed();
 392 
 393   static unsigned char global_unloading_clock()   { return _global_unloading_clock; }
 394   static void increase_unloading_clock();
 395 
 396   void set_unloading_clock(unsigned char unloading_clock);
 397   unsigned char unloading_clock();
 398 
 399 protected:
 400   virtual bool do_unloading_oops(address low_boundary, BoolObjectClosure* is_alive) = 0;
 401 #if INCLUDE_JVMCI
 402   virtual bool do_unloading_jvmci() = 0;
 403 #endif
 404 
 405 private:
 406   // GC support to help figure out if an nmethod has been
 407   // cleaned/unloaded by the current GC.
 408   static unsigned char _global_unloading_clock;
 409 
 410   volatile unsigned char _unloading_clock;   // Incremented after GC unloaded/cleaned the nmethod
 411 
 412   PcDesc* find_pc_desc(address pc, bool approximate) {
 413     return _pc_desc_container.find_pc_desc(pc, approximate, PcDescSearch(code_begin(), scopes_pcs_begin(), scopes_pcs_end()));
 414   }
 415 
 416 protected:
 417   union {
 418     // Used by G1 to chain nmethods.
 419     CompiledMethod* _unloading_next;
 420     // Used by non-G1 GCs to chain nmethods.
 421     nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods
 422   };
 423 };
 424 
 425 #endif //SHARE_VM_CODE_COMPILEDMETHOD_HPP