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