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src/hotspot/share/code/vtableStubs.hpp

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 69 
 70 // VtableStubs creates the code stubs for compiled calls through vtables.
 71 // There is one stub per (vtable index, args_size) pair, and the stubs are
 72 // never deallocated. They don't need to be GCed because they contain no oops.
 73 class VtableStub;
 74 
 75 class VtableStubs : AllStatic {
 76  public:                                         // N must be public (some compilers need this for _table)
 77   enum {
 78     N    = 256,                                  // size of stub table; must be power of two
 79     mask = N - 1
 80   };
 81 
 82  private:
 83   friend class VtableStub;
 84   static VtableStub* _table[N];                  // table of existing stubs
 85   static int         _number_of_vtable_stubs;    // number of stubs created so far (for statistics)
 86   static int         _vtab_stub_size;            // current size estimate for vtable stub (quasi-constant)
 87   static int         _itab_stub_size;            // current size estimate for itable stub (quasi-constant)
 88 
 89   static VtableStub* create_vtable_stub(int vtable_index);
 90   static VtableStub* create_itable_stub(int vtable_index);
 91   static VtableStub* lookup            (bool is_vtable_stub, int vtable_index);
 92   static void        enter             (bool is_vtable_stub, int vtable_index, VtableStub* s);
 93   static inline uint hash              (bool is_vtable_stub, int vtable_index);
 94   static address     find_stub         (bool is_vtable_stub, int vtable_index);
 95   static void        bookkeeping(MacroAssembler* masm, outputStream* out, VtableStub* s,
 96                                  address npe_addr, address ame_addr,   bool is_vtable_stub,
 97                                  int     index,    int     slop_bytes, int  index_dependent_slop);
 98   static int         code_size_limit(bool is_vtable_stub);
 99   static void        check_and_set_size_limit(bool is_vtable_stub,
100                                               int   code_size,
101                                               int   padding);
102 
103  public:
104   static address     find_vtable_stub(int vtable_index) { return find_stub(true,  vtable_index); }
105   static address     find_itable_stub(int itable_index) { return find_stub(false, itable_index); }
106 
107   static VtableStub* entry_point(address pc);                        // vtable stub entry point for a pc
108   static bool        contains(address pc);                           // is pc within any stub?
109   static VtableStub* stub_containing(address pc);                    // stub containing pc or NULL
110   static int         number_of_vtable_stubs() { return _number_of_vtable_stubs; }
111   static void        initialize();
112   static void        vtable_stub_do(void f(VtableStub*));            // iterates over all vtable stubs
113 };
114 
115 
116 class VtableStub {
117  private:
118   friend class VtableStubs;
119 
120   static address _chunk;             // For allocation
121   static address _chunk_end;         // For allocation
122   static VMReg   _receiver_location; // Where to find receiver
123 
124   VtableStub*    _next;              // Pointer to next entry in hash table
125   const short    _index;             // vtable index
126   short          _ame_offset;        // Where an AbstractMethodError might occur
127   short          _npe_offset;        // Where a NullPointerException might occur
128   bool           _is_vtable_stub;    // True if vtable stub, false, is itable stub


129   /* code follows here */            // The vtableStub code
130 
131   void* operator new(size_t size, int code_size) throw();
132 
133   VtableStub(bool is_vtable_stub, int index)
134         : _next(NULL), _index(index), _ame_offset(-1), _npe_offset(-1),
135           _is_vtable_stub(is_vtable_stub) {}
136   VtableStub* next() const                       { return _next; }
137   int index() const                              { return _index; }
138   static VMReg receiver_location()               { return _receiver_location; }
139   void set_next(VtableStub* n)                   { _next = n; }
140 
141  public:
142   address code_begin() const                     { return (address)(this + 1); }
143   address code_end() const                       { return code_begin() + VtableStubs::code_size_limit(_is_vtable_stub); }
144   address entry_point() const                    { return code_begin(); }
145   static int entry_offset()                      { return sizeof(class VtableStub); }
146 
147   bool matches(bool is_vtable_stub, int index) const {
148     return _index == index && _is_vtable_stub == is_vtable_stub;
149   }
150   bool contains(address pc) const                { return code_begin() <= pc && pc < code_end(); }
151 
152  private:
153   void set_exception_points(address npe_addr, address ame_addr) {
154     _npe_offset = npe_addr - code_begin();
155     _ame_offset = ame_addr - code_begin();
156     assert(is_abstract_method_error(ame_addr),   "offset must be correct");
157     assert(is_null_pointer_exception(npe_addr),  "offset must be correct");
158     assert(!is_abstract_method_error(npe_addr),  "offset must be correct");
159     assert(!is_null_pointer_exception(ame_addr), "offset must be correct");
160   }
161 
162   // platform-dependent routines
163   static int  pd_code_alignment();
164   // CNC: Removed because vtable stubs are now made with an ideal graph
165   // static bool pd_disregard_arg_size();
166 
167   static void align_chunk() {
168     uintptr_t off = (uintptr_t)( _chunk + sizeof(VtableStub) ) % pd_code_alignment();
169     if (off != 0)  _chunk += pd_code_alignment() - off;
170   }
171 
172  public:
173   // Query
174   bool is_itable_stub()                          { return !_is_vtable_stub; }
175   bool is_vtable_stub()                          { return  _is_vtable_stub; }

176   bool is_abstract_method_error(address epc)     { return epc == code_begin()+_ame_offset; }
177   bool is_null_pointer_exception(address epc)    { return epc == code_begin()+_npe_offset; }
178 
179   void print_on(outputStream* st) const;
180   void print() const;
181 
182 };
183 
184 #endif // SHARE_CODE_VTABLESTUBS_HPP

 69 
 70 // VtableStubs creates the code stubs for compiled calls through vtables.
 71 // There is one stub per (vtable index, args_size) pair, and the stubs are
 72 // never deallocated. They don't need to be GCed because they contain no oops.
 73 class VtableStub;
 74 
 75 class VtableStubs : AllStatic {
 76  public:                                         // N must be public (some compilers need this for _table)
 77   enum {
 78     N    = 256,                                  // size of stub table; must be power of two
 79     mask = N - 1
 80   };
 81 
 82  private:
 83   friend class VtableStub;
 84   static VtableStub* _table[N];                  // table of existing stubs
 85   static int         _number_of_vtable_stubs;    // number of stubs created so far (for statistics)
 86   static int         _vtab_stub_size;            // current size estimate for vtable stub (quasi-constant)
 87   static int         _itab_stub_size;            // current size estimate for itable stub (quasi-constant)
 88 
 89   static VtableStub* create_vtable_stub(int vtable_index, bool caller_is_c1);
 90   static VtableStub* create_itable_stub(int vtable_index, bool caller_is_c1);
 91   static VtableStub* lookup            (bool is_vtable_stub, int vtable_index, bool caller_is_c1);
 92   static void        enter             (bool is_vtable_stub, int vtable_index, bool caller_is_c1, VtableStub* s);
 93   static inline uint hash              (bool is_vtable_stub, int vtable_index, bool caller_is_c1);
 94   static address     find_stub         (bool is_vtable_stub, int vtable_index, bool caller_is_c1);
 95   static void        bookkeeping(MacroAssembler* masm, outputStream* out, VtableStub* s,
 96                                  address npe_addr, address ame_addr,   bool is_vtable_stub,
 97                                  int     index,    int     slop_bytes, int  index_dependent_slop);
 98   static int         code_size_limit(bool is_vtable_stub);
 99   static void        check_and_set_size_limit(bool is_vtable_stub,
100                                               int   code_size,
101                                               int   padding);
102 
103  public:
104   static address     find_vtable_stub(int vtable_index, bool caller_is_c1) { return find_stub(true,  vtable_index, caller_is_c1); }
105   static address     find_itable_stub(int itable_index, bool caller_is_c1) { return find_stub(false, itable_index, caller_is_c1); }
106 
107   static VtableStub* entry_point(address pc);                        // vtable stub entry point for a pc
108   static bool        contains(address pc);                           // is pc within any stub?
109   static VtableStub* stub_containing(address pc);                    // stub containing pc or NULL
110   static int         number_of_vtable_stubs() { return _number_of_vtable_stubs; }
111   static void        initialize();
112   static void        vtable_stub_do(void f(VtableStub*));            // iterates over all vtable stubs
113 };
114 
115 
116 class VtableStub {
117  private:
118   friend class VtableStubs;
119 
120   static address _chunk;             // For allocation
121   static address _chunk_end;         // For allocation
122   static VMReg   _receiver_location; // Where to find receiver
123 
124   VtableStub*    _next;              // Pointer to next entry in hash table
125   const short    _index;             // vtable index
126   short          _ame_offset;        // Where an AbstractMethodError might occur
127   short          _npe_offset;        // Where a NullPointerException might occur
128   bool           _is_vtable_stub;    // True if vtable stub, false, is itable stub
129   bool           _caller_is_c1;      // True if this is for a caller compiled by C1,
130                                      // which doesn't scalarize parameters.
131   /* code follows here */            // The vtableStub code
132 
133   void* operator new(size_t size, int code_size) throw();
134 
135   VtableStub(bool is_vtable_stub, int index, bool caller_is_c1)
136         : _next(NULL), _index(index), _ame_offset(-1), _npe_offset(-1),
137           _is_vtable_stub(is_vtable_stub), _caller_is_c1(caller_is_c1) {}
138   VtableStub* next() const                       { return _next; }
139   int index() const                              { return _index; }
140   static VMReg receiver_location()               { return _receiver_location; }
141   void set_next(VtableStub* n)                   { _next = n; }
142 
143  public:
144   address code_begin() const                     { return (address)(this + 1); }
145   address code_end() const                       { return code_begin() + VtableStubs::code_size_limit(_is_vtable_stub); }
146   address entry_point() const                    { return code_begin(); }
147   static int entry_offset()                      { return sizeof(class VtableStub); }
148 
149   bool matches(bool is_vtable_stub, int index, bool caller_is_c1) const {
150     return _index == index && _is_vtable_stub == is_vtable_stub && _caller_is_c1 == caller_is_c1;
151   }
152   bool contains(address pc) const                { return code_begin() <= pc && pc < code_end(); }
153 
154  private:
155   void set_exception_points(address npe_addr, address ame_addr) {
156     _npe_offset = npe_addr - code_begin();
157     _ame_offset = ame_addr - code_begin();
158     assert(is_abstract_method_error(ame_addr),   "offset must be correct");
159     assert(is_null_pointer_exception(npe_addr),  "offset must be correct");
160     assert(!is_abstract_method_error(npe_addr),  "offset must be correct");
161     assert(!is_null_pointer_exception(ame_addr), "offset must be correct");
162   }
163 
164   // platform-dependent routines
165   static int  pd_code_alignment();
166   // CNC: Removed because vtable stubs are now made with an ideal graph
167   // static bool pd_disregard_arg_size();
168 
169   static void align_chunk() {
170     uintptr_t off = (uintptr_t)( _chunk + sizeof(VtableStub) ) % pd_code_alignment();
171     if (off != 0)  _chunk += pd_code_alignment() - off;
172   }
173 
174  public:
175   // Query
176   bool is_itable_stub()                          { return !_is_vtable_stub; }
177   bool is_vtable_stub()                          { return  _is_vtable_stub; }
178   bool caller_is_c1()                            { return  _caller_is_c1;   }
179   bool is_abstract_method_error(address epc)     { return epc == code_begin()+_ame_offset; }
180   bool is_null_pointer_exception(address epc)    { return epc == code_begin()+_npe_offset; }
181 
182   void print_on(outputStream* st) const;
183   void print() const;
184 
185 };
186 
187 #endif // SHARE_CODE_VTABLESTUBS_HPP
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