1 /* 2 * Copyright (c) 1998, 2009, 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 // Interface for generating the frame map for compiled code. A frame map 26 // describes for a specific pc whether each register and frame stack slot is: 27 // Oop - A GC root for current frame 28 // Value - Live non-oop, non-float value: int, either half of double 29 // Dead - Dead; can be Zapped for debugging 30 // CalleeXX - Callee saved; also describes which caller register is saved 31 // DerivedXX - A derived oop; original oop is described. 32 // 33 // OopMapValue describes a single OopMap entry 34 35 class frame; 36 class RegisterMap; 37 class DerivedPointerEntry; 38 39 class OopMapValue: public StackObj { 40 friend class VMStructs; 41 private: 42 short _value; 43 int value() const { return _value; } 44 void set_value(int value) { _value = value; } 45 short _content_reg; 46 47 public: 48 // Constants 49 enum { type_bits = 5, 50 register_bits = BitsPerShort - type_bits }; 51 52 enum { type_shift = 0, 53 register_shift = type_bits }; 54 55 enum { type_mask = right_n_bits(type_bits), 56 type_mask_in_place = type_mask << type_shift, 57 register_mask = right_n_bits(register_bits), 58 register_mask_in_place = register_mask << register_shift }; 59 60 enum oop_types { // must fit in type_bits 61 unused_value =0, // powers of 2, for masking OopMapStream 62 oop_value = 1, 63 value_value = 2, 64 narrowoop_value = 4, 65 callee_saved_value = 8, 66 derived_oop_value= 16 }; 67 68 // Constructors 69 OopMapValue () { set_value(0); set_content_reg(VMRegImpl::Bad()); } 70 OopMapValue (VMReg reg, oop_types t) { set_reg_type(reg,t); } 71 OopMapValue (VMReg reg, oop_types t, VMReg reg2) { set_reg_type(reg,t); set_content_reg(reg2); } 72 OopMapValue (CompressedReadStream* stream) { read_from(stream); } 73 74 // Archiving 75 void write_on(CompressedWriteStream* stream) { 76 stream->write_int(value()); 77 if(is_callee_saved() || is_derived_oop()) { 78 stream->write_int(content_reg()->value()); 79 } 80 } 81 82 void read_from(CompressedReadStream* stream) { 83 set_value(stream->read_int()); 84 if(is_callee_saved() || is_derived_oop()) { 85 set_content_reg(VMRegImpl::as_VMReg(stream->read_int(), true)); 86 } 87 } 88 89 // Querying 90 bool is_oop() { return mask_bits(value(), type_mask_in_place) == oop_value; } 91 bool is_value() { return mask_bits(value(), type_mask_in_place) == value_value; } 92 bool is_narrowoop() { return mask_bits(value(), type_mask_in_place) == narrowoop_value; } 93 bool is_callee_saved() { return mask_bits(value(), type_mask_in_place) == callee_saved_value; } 94 bool is_derived_oop() { return mask_bits(value(), type_mask_in_place) == derived_oop_value; } 95 96 void set_oop() { set_value((value() & register_mask_in_place) | oop_value); } 97 void set_value() { set_value((value() & register_mask_in_place) | value_value); } 98 void set_narrowoop() { set_value((value() & register_mask_in_place) | narrowoop_value); } 99 void set_callee_saved() { set_value((value() & register_mask_in_place) | callee_saved_value); } 100 void set_derived_oop() { set_value((value() & register_mask_in_place) | derived_oop_value); } 101 102 VMReg reg() const { return VMRegImpl::as_VMReg(mask_bits(value(), register_mask_in_place) >> register_shift); } 103 oop_types type() const { return (oop_types)mask_bits(value(), type_mask_in_place); } 104 105 static bool legal_vm_reg_name(VMReg p) { 106 return (p->value() == (p->value() & register_mask)); 107 } 108 109 void set_reg_type(VMReg p, oop_types t) { 110 set_value((p->value() << register_shift) | t); 111 assert(reg() == p, "sanity check" ); 112 assert(type() == t, "sanity check" ); 113 } 114 115 116 VMReg content_reg() const { return VMRegImpl::as_VMReg(_content_reg, true); } 117 void set_content_reg(VMReg r) { _content_reg = r->value(); } 118 119 // Physical location queries 120 bool is_register_loc() { return reg()->is_reg(); } 121 bool is_stack_loc() { return reg()->is_stack(); } 122 123 // Returns offset from sp. 124 int stack_offset() { 125 assert(is_stack_loc(), "must be stack location"); 126 return reg()->reg2stack(); 127 } 128 129 void print_on(outputStream* st) const; 130 void print() const { print_on(tty); } 131 }; 132 133 134 class OopMap: public ResourceObj { 135 friend class OopMapStream; 136 friend class VMStructs; 137 private: 138 int _pc_offset; 139 int _omv_count; 140 int _omv_data_size; 141 unsigned char* _omv_data; 142 CompressedWriteStream* _write_stream; 143 144 debug_only( OopMapValue::oop_types* _locs_used; int _locs_length;) 145 146 // Accessors 147 unsigned char* omv_data() const { return _omv_data; } 148 void set_omv_data(unsigned char* value) { _omv_data = value; } 149 int omv_data_size() const { return _omv_data_size; } 150 void set_omv_data_size(int value) { _omv_data_size = value; } 151 int omv_count() const { return _omv_count; } 152 void set_omv_count(int value) { _omv_count = value; } 153 void increment_count() { _omv_count++; } 154 CompressedWriteStream* write_stream() const { return _write_stream; } 155 void set_write_stream(CompressedWriteStream* value) { _write_stream = value; } 156 157 private: 158 enum DeepCopyToken { _deep_copy_token }; 159 OopMap(DeepCopyToken, OopMap* source); // used only by deep_copy 160 161 public: 162 OopMap(int frame_size, int arg_count); 163 164 // pc-offset handling 165 int offset() const { return _pc_offset; } 166 void set_offset(int o) { _pc_offset = o; } 167 168 // Check to avoid double insertion 169 debug_only(OopMapValue::oop_types locs_used( int indx ) { return _locs_used[indx]; }) 170 171 // Construction 172 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd 173 // slots to hold 4-byte values like ints and floats in the LP64 build. 174 void set_oop ( VMReg local); 175 void set_value( VMReg local); 176 void set_narrowoop(VMReg local); 177 void set_dead ( VMReg local); 178 void set_callee_saved( VMReg local, VMReg caller_machine_register ); 179 void set_derived_oop ( VMReg local, VMReg derived_from_local_register ); 180 void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional); 181 182 int heap_size() const; 183 void copy_to(address addr); 184 OopMap* deep_copy(); 185 186 bool has_derived_pointer() const PRODUCT_RETURN0; 187 188 bool legal_vm_reg_name(VMReg local) { 189 return OopMapValue::legal_vm_reg_name(local); 190 } 191 192 // Printing 193 void print_on(outputStream* st) const; 194 void print() const { print_on(tty); } 195 }; 196 197 198 class OopMapSet : public ResourceObj { 199 friend class VMStructs; 200 private: 201 int _om_count; 202 int _om_size; 203 OopMap** _om_data; 204 205 int om_count() const { return _om_count; } 206 void set_om_count(int value) { _om_count = value; } 207 void increment_count() { _om_count++; } 208 int om_size() const { return _om_size; } 209 void set_om_size(int value) { _om_size = value; } 210 OopMap** om_data() const { return _om_data; } 211 void set_om_data(OopMap** value) { _om_data = value; } 212 void grow_om_data(); 213 void set(int index,OopMap* value) { assert((index == 0) || ((index > 0) && (index < om_size())),"bad index"); _om_data[index] = value; } 214 215 public: 216 OopMapSet(); 217 218 // returns the number of OopMaps in this OopMapSet 219 int size() const { return _om_count; } 220 // returns the OopMap at a given index 221 OopMap* at(int index) const { assert((index >= 0) && (index <= om_count()),"bad index"); return _om_data[index]; } 222 223 // Collect OopMaps. 224 void add_gc_map(int pc, OopMap* map); 225 226 // Returns the only oop map. Used for reconstructing 227 // Adapter frames during deoptimization 228 OopMap* singular_oop_map(); 229 230 // returns OopMap in that is anchored to the pc 231 OopMap* find_map_at_offset(int pc_offset) const; 232 233 int heap_size() const; 234 void copy_to(address addr); 235 236 // Methods oops_do() and all_do() filter out NULL oops and 237 // oop == Universe::narrow_oop_base() before passing oops 238 // to closures. 239 240 // Iterates through frame for a compiled method 241 static void oops_do (const frame* fr, 242 const RegisterMap* reg_map, OopClosure* f); 243 static void update_register_map(const frame* fr, RegisterMap *reg_map); 244 245 // Iterates through frame for a compiled method for dead ones and values, too 246 static void all_do(const frame* fr, const RegisterMap* reg_map, 247 OopClosure* oop_fn, 248 void derived_oop_fn(oop* base, oop* derived), 249 OopClosure* value_fn); 250 251 // Printing 252 void print_on(outputStream* st) const; 253 void print() const { print_on(tty); } 254 }; 255 256 257 class OopMapStream : public StackObj { 258 private: 259 CompressedReadStream* _stream; 260 int _mask; 261 int _size; 262 int _position; 263 bool _valid_omv; 264 OopMapValue _omv; 265 void find_next(); 266 267 public: 268 OopMapStream(OopMap* oop_map); 269 OopMapStream(OopMap* oop_map, int oop_types_mask); 270 bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; } 271 void next() { find_next(); } 272 OopMapValue current() { return _omv; } 273 }; 274 275 276 // Derived pointer support. This table keeps track of all derived points on a 277 // stack. It is cleared before each scavenge/GC. During the traversal of all 278 // oops, it is filled in with references to all locations that contains a 279 // derived oop (assumed to be very few). When the GC is complete, the derived 280 // pointers are updated based on their base pointers new value and an offset. 281 #ifdef COMPILER2 282 class DerivedPointerTable : public AllStatic { 283 friend class VMStructs; 284 private: 285 static GrowableArray<DerivedPointerEntry*>* _list; 286 static bool _active; // do not record pointers for verify pass etc. 287 public: 288 static void clear(); // Called before scavenge/GC 289 static void add(oop *derived, oop *base); // Called during scavenge/GC 290 static void update_pointers(); // Called after scavenge/GC 291 static bool is_empty() { return _list == NULL || _list->is_empty(); } 292 static bool is_active() { return _active; } 293 static void set_active(bool value) { _active = value; } 294 }; 295 296 // A utility class to temporarily "deactivate" the DerivedPointerTable. 297 // (Note: clients are responsible for any MT-safety issues) 298 class DerivedPointerTableDeactivate: public StackObj { 299 private: 300 bool _active; 301 public: 302 DerivedPointerTableDeactivate() { 303 _active = DerivedPointerTable::is_active(); 304 if (_active) { 305 DerivedPointerTable::set_active(false); 306 } 307 } 308 309 ~DerivedPointerTableDeactivate() { 310 assert(!DerivedPointerTable::is_active(), 311 "Inconsistency: not MT-safe"); 312 if (_active) { 313 DerivedPointerTable::set_active(true); 314 } 315 } 316 }; 317 #endif // COMPILER2