1 /*
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  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  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).
 14  *
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 18  *
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 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 #include "oops/method.hpp"
 32 
 33 class Dependencies;
 34 class ExceptionHandlerTable;
 35 class ImplicitExceptionTable;
 36 class AbstractCompiler;
 37 class xmlStream;
 38 class CompiledDirectCall;
 39 class NativeCallWrapper;
 40 class ScopeDesc;
 41 class CompiledIC;
 42 class MetadataClosure;
 43 
 44 // This class is used internally by nmethods, to cache
 45 // exception/pc/handler information.
 46 
 47 class ExceptionCache : public CHeapObj<mtCode> {
 48   friend class VMStructs;
 49  private:
 50   enum { cache_size = 16 };
 51   Klass*   _exception_type;
 52   address  _pc[cache_size];
 53   address  _handler[cache_size];
 54   volatile int _count;
 55   ExceptionCache* volatile _next;
 56   ExceptionCache* _purge_list_next;
 57 
 58   inline address pc_at(int index);
 59   void set_pc_at(int index, address a)      { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
 60 
 61   inline address handler_at(int index);
 62   void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
 63 
 64   inline int count();
 65   // increment_count is only called under lock, but there may be concurrent readers.
 66   void increment_count();
 67 
 68  public:
 69 
 70   ExceptionCache(Handle exception, address pc, address handler);
 71 
 72   Klass*    exception_type()                { return _exception_type; }
 73   ExceptionCache* next();
 74   void      set_next(ExceptionCache *ec);
 75   ExceptionCache* purge_list_next()                 { return _purge_list_next; }
 76   void      set_purge_list_next(ExceptionCache *ec) { _purge_list_next = ec; }
 77 
 78   address match(Handle exception, address pc);
 79   bool    match_exception_with_space(Handle exception) ;
 80   address test_address(address addr);
 81   bool    add_address_and_handler(address addr, address handler) ;
 82 };
 83 
 84 class nmethod;
 85 
 86 // cache pc descs found in earlier inquiries
 87 class PcDescCache {
 88   friend class VMStructs;
 89  private:
 90   enum { cache_size = 4 };
 91   // The array elements MUST be volatile! Several threads may modify
 92   // and read from the cache concurrently. find_pc_desc_internal has
 93   // returned wrong results. C++ compiler (namely xlC12) may duplicate
 94   // C++ field accesses if the elements are not volatile.
 95   typedef PcDesc* PcDescPtr;
 96   volatile PcDescPtr _pc_descs[cache_size]; // last cache_size pc_descs found
 97  public:
 98   PcDescCache() { debug_only(_pc_descs[0] = nullptr); }
 99   void    reset_to(PcDesc* initial_pc_desc);
100   PcDesc* find_pc_desc(int pc_offset, bool approximate);
101   void    add_pc_desc(PcDesc* pc_desc);
102   PcDesc* last_pc_desc() { return _pc_descs[0]; }
103 };
104 
105 class PcDescSearch {
106 private:
107   address _code_begin;
108   PcDesc* _lower;
109   PcDesc* _upper;
110 public:
111   PcDescSearch(address code, PcDesc* lower, PcDesc* upper) :
112     _code_begin(code), _lower(lower), _upper(upper)
113   {
114   }
115 
116   address code_begin() const { return _code_begin; }
117   PcDesc* scopes_pcs_begin() const { return _lower; }
118   PcDesc* scopes_pcs_end() const { return _upper; }
119 };
120 
121 class PcDescContainer {
122 private:
123   PcDescCache _pc_desc_cache;
124 public:
125   PcDescContainer() {}
126 
127   PcDesc* find_pc_desc_internal(address pc, bool approximate, const PcDescSearch& search);
128   void    reset_to(PcDesc* initial_pc_desc) { _pc_desc_cache.reset_to(initial_pc_desc); }
129 
130   PcDesc* find_pc_desc(address pc, bool approximate, const PcDescSearch& search) {
131     address base_address = search.code_begin();
132     PcDesc* desc = _pc_desc_cache.last_pc_desc();
133     if (desc != nullptr && desc->pc_offset() == pc - base_address) {
134       return desc;
135     }
136     return find_pc_desc_internal(pc, approximate, search);
137   }
138 };
139 
140 
141 class CompiledMethod : public CodeBlob {
142   friend class VMStructs;
143   friend class DeoptimizationScope;
144   void init_defaults();
145 protected:
146   enum DeoptimizationStatus : u1 {
147     not_marked,
148     deoptimize,
149     deoptimize_noupdate,
150     deoptimize_done
151   };
152 
153   volatile DeoptimizationStatus _deoptimization_status; // Used for stack deoptimization
154   // Used to track in which deoptimize handshake this method will be deoptimized.
155   uint64_t                      _deoptimization_generation;
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 _has_wide_vectors:1;          // Preserve wide vectors at safepoints
161   unsigned int _has_monitors:1;              // Fastpath monitor detection for continuations
162   unsigned int _preloaded:1;
163   unsigned int _has_clinit_barriers:1;
164 
165   Method*   _method;
166   address _scopes_data_begin;
167   // All deoptee's will resume execution at this location described by
168   // this address.
169   address _deopt_handler_begin;
170   // All deoptee's at a MethodHandle call site will resume execution
171   // at this location described by this offset.
172   address _deopt_mh_handler_begin;
173 
174   PcDescContainer _pc_desc_container;
175   ExceptionCache * volatile _exception_cache;
176 
177   void* _gc_data;
178 
179   virtual void purge(bool free_code_cache_data, bool unregister_nmethod) = 0;
180 
181 private:
182   DeoptimizationStatus deoptimization_status() const {
183     return Atomic::load(&_deoptimization_status);
184   }
185 
186 protected:
187   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, bool compiled);
188   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, bool compiled);
189 
190 public:
191   // Only used by unit test.
192   CompiledMethod() {}
193 
194   template<typename T>
195   T* gc_data() const                              { return reinterpret_cast<T*>(_gc_data); }
196   template<typename T>
197   void set_gc_data(T* gc_data)                    { _gc_data = reinterpret_cast<void*>(gc_data); }
198 
199   bool  has_unsafe_access() const                 { return _has_unsafe_access; }
200   void  set_has_unsafe_access(bool z)             { _has_unsafe_access = z; }
201 
202   bool  has_monitors() const                      { return _has_monitors; }
203   void  set_has_monitors(bool z)                  { _has_monitors = z; }
204 
205   bool  has_method_handle_invokes() const         { return _has_method_handle_invokes; }
206   void  set_has_method_handle_invokes(bool z)     { _has_method_handle_invokes = z; }
207 
208   bool  has_wide_vectors() const                  { return _has_wide_vectors; }
209   void  set_has_wide_vectors(bool z)              { _has_wide_vectors = z; }
210 
211   bool  has_clinit_barriers() const               { return _has_clinit_barriers; }
212   void  set_has_clinit_barriers(bool z)           { _has_clinit_barriers = z; }
213 
214   bool  preloaded() const                         { return _preloaded; }
215   void  set_preloaded(bool z)                     { _preloaded = z; }
216 
217   enum : signed char { not_installed = -1, // in construction, only the owner doing the construction is
218                                            // allowed to advance state
219                        in_use        = 0,  // executable nmethod
220                        not_used      = 1,  // not entrant, but revivable
221                        not_entrant   = 2,  // marked for deoptimization but activations may still exist
222   };
223 
224   virtual bool  is_in_use() const = 0;
225   virtual int   comp_level() const = 0;
226   virtual int   compile_id() const = 0;
227   virtual bool  is_scc() const = 0;
228 
229   virtual address verified_entry_point() const = 0;
230   virtual void log_identity(xmlStream* log) const = 0;
231   virtual void log_state_change() const = 0;
232   virtual bool make_not_used() = 0;
233   virtual bool make_not_entrant(bool make_not_entrant = true) = 0;
234   virtual bool make_entrant() = 0;
235   virtual address entry_point() const = 0;
236   virtual bool is_osr_method() const = 0;
237   virtual int osr_entry_bci() const = 0;
238   Method* method() const                          { return _method; }
239   virtual void print_pcs_on(outputStream* st) = 0;
240   bool is_native_method() const { return _method != nullptr && _method->is_native(); }
241   bool is_java_method() const { return _method != nullptr && !_method->is_native(); }
242 
243   // ScopeDesc retrieval operation
244   PcDesc* pc_desc_at(address pc)   { return find_pc_desc(pc, false); }
245   // pc_desc_near returns the first PcDesc at or after the given pc.
246   PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
247 
248   // ScopeDesc for an instruction
249   ScopeDesc* scope_desc_at(address pc);
250   ScopeDesc* scope_desc_near(address pc);
251 
252   bool is_at_poll_return(address pc);
253   bool is_at_poll_or_poll_return(address pc);
254 
255   bool  is_marked_for_deoptimization() const { return deoptimization_status() != not_marked; }
256   bool  has_been_deoptimized() const { return deoptimization_status() == deoptimize_done; }
257   void  set_deoptimized_done();
258 
259   virtual void  make_deoptimized() { assert(false, "not supported"); };
260 
261   bool update_recompile_counts() const {
262     // Update recompile counts when either the update is explicitly requested (deoptimize)
263     // or the nmethod is not marked for deoptimization at all (not_marked).
264     // The latter happens during uncommon traps when deoptimized nmethod is made not entrant.
265     DeoptimizationStatus status = deoptimization_status();
266     return status != deoptimize_noupdate && status != deoptimize_done;
267   }
268 
269   // tells whether frames described by this nmethod can be deoptimized
270   // note: native wrappers cannot be deoptimized.
271   bool can_be_deoptimized() const { return is_java_method(); }
272 
273   virtual oop oop_at(int index) const = 0;
274   virtual Metadata* metadata_at(int index) const = 0;
275 
276   address scopes_data_begin() const { return _scopes_data_begin; }
277   virtual address scopes_data_end() const = 0;
278   int scopes_data_size() const { return int(scopes_data_end() - scopes_data_begin()); }
279 
280   virtual PcDesc* scopes_pcs_begin() const = 0;
281   virtual PcDesc* scopes_pcs_end() const = 0;
282   int scopes_pcs_size() const { return int((intptr_t) scopes_pcs_end() - (intptr_t) scopes_pcs_begin()); }
283 
284   address insts_begin() const { return code_begin(); }
285   address insts_end() const { return stub_begin(); }
286   // Returns true if a given address is in the 'insts' section. The method
287   // insts_contains_inclusive() is end-inclusive.
288   bool insts_contains(address addr) const { return insts_begin() <= addr && addr < insts_end(); }
289   bool insts_contains_inclusive(address addr) const { return insts_begin() <= addr && addr <= insts_end(); }
290 
291   int insts_size() const { return int(insts_end() - insts_begin()); }
292 
293   virtual address consts_begin() const = 0;
294   virtual address consts_end() const = 0;
295   bool consts_contains(address addr) const { return consts_begin() <= addr && addr < consts_end(); }
296   int consts_size() const { return int(consts_end() - consts_begin()); }
297 
298   virtual int skipped_instructions_size() const = 0;
299 
300   virtual address stub_begin() const = 0;
301   virtual address stub_end() const = 0;
302   bool stub_contains(address addr) const { return stub_begin() <= addr && addr < stub_end(); }
303   int stub_size() const { return int(stub_end() - stub_begin()); }
304 
305   virtual address handler_table_begin() const = 0;
306   virtual address handler_table_end() const = 0;
307   bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
308   int handler_table_size() const { return int(handler_table_end() - handler_table_begin()); }
309 
310   virtual address exception_begin() const = 0;
311 
312   virtual address nul_chk_table_begin() const = 0;
313   virtual address nul_chk_table_end() const = 0;
314   bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
315   int nul_chk_table_size() const { return int(nul_chk_table_end() - nul_chk_table_begin()); }
316 
317   virtual oop* oop_addr_at(int index) const = 0;
318   virtual Metadata** metadata_addr_at(int index) const = 0;
319 
320 protected:
321   // Exception cache support
322   // Note: _exception_cache may be read and cleaned concurrently.
323   ExceptionCache* exception_cache() const         { return _exception_cache; }
324   ExceptionCache* exception_cache_acquire() const;
325   void set_exception_cache(ExceptionCache *ec)    { _exception_cache = ec; }
326 
327 public:
328   address handler_for_exception_and_pc(Handle exception, address pc);
329   void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
330   void clean_exception_cache();
331 
332   void add_exception_cache_entry(ExceptionCache* new_entry);
333   ExceptionCache* exception_cache_entry_for_exception(Handle exception);
334 
335   // MethodHandle
336   bool is_method_handle_return(address return_pc);
337   address deopt_mh_handler_begin() const  { return _deopt_mh_handler_begin; }
338 
339   address deopt_handler_begin() const { return _deopt_handler_begin; }
340   address* deopt_handler_begin_addr() { return &_deopt_handler_begin; }
341   // Deopt
342   // Return true is the PC is one would expect if the frame is being deopted.
343   inline bool is_deopt_pc(address pc);
344   inline bool is_deopt_mh_entry(address pc);
345   inline bool is_deopt_entry(address pc);
346 
347   // Accessor/mutator for the original pc of a frame before a frame was deopted.
348   address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
349   void    set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
350 
351   virtual int orig_pc_offset() = 0;
352 
353 private:
354   address* orig_pc_addr(const frame* fr);
355 
356 public:
357   virtual const char* compile_kind() const = 0;
358   virtual int get_state() const = 0;
359 
360   const char* state() const;
361 
362   bool inlinecache_check_contains(address addr) const {
363     return (addr >= code_begin() && addr < verified_entry_point());
364   }
365 
366   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f);
367 
368   // implicit exceptions support
369   address continuation_for_implicit_div0_exception(address pc) { return continuation_for_implicit_exception(pc, true); }
370   address continuation_for_implicit_null_exception(address pc) { return continuation_for_implicit_exception(pc, false); }
371 
372   static address get_deopt_original_pc(const frame* fr);
373 
374   // Inline cache support for class unloading and nmethod unloading
375  private:
376   void cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all);
377 
378   address continuation_for_implicit_exception(address pc, bool for_div0_check);
379 
380  public:
381   // Serial version used by whitebox test
382   void cleanup_inline_caches_whitebox();
383 
384   virtual void clear_inline_caches();
385 
386   // Execute nmethod barrier code, as if entering through nmethod call.
387   void run_nmethod_entry_barrier();
388 
389   void verify_oop_relocations();
390 
391   bool has_evol_metadata();
392 
393   // Fast breakpoint support. Tells if this compiled method is
394   // dependent on the given method. Returns true if this nmethod
395   // corresponds to the given method as well.
396   virtual bool is_dependent_on_method(Method* dependee) = 0;
397 
398   virtual address call_instruction_address(address pc) const = 0;
399 
400   Method* attached_method(address call_pc);
401   Method* attached_method_before_pc(address pc);
402 
403   virtual void metadata_do(MetadataClosure* f) = 0;
404 
405   // GC support
406  protected:
407   address oops_reloc_begin() const;
408 
409  public:
410   // GC unloading support
411   // Cleans unloaded klasses and unloaded nmethods in inline caches
412 
413   virtual bool is_unloading() = 0;
414 
415   void unload_nmethod_caches(bool class_unloading_occurred);
416   virtual void do_unloading(bool unloading_occurred) = 0;
417 
418 private:
419   PcDesc* find_pc_desc(address pc, bool approximate) {
420     return _pc_desc_container.find_pc_desc(pc, approximate, PcDescSearch(code_begin(), scopes_pcs_begin(), scopes_pcs_end()));
421   }
422 };
423 
424 #endif // SHARE_CODE_COMPILEDMETHOD_HPP