1 /* 2 * Copyright (c) 1997, 2012, 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_NMETHOD_HPP 26 #define SHARE_VM_CODE_NMETHOD_HPP 27 28 #include "code/codeBlob.hpp" 29 #include "code/pcDesc.hpp" 30 #include "oops/metadata.hpp" 31 32 // This class is used internally by nmethods, to cache 33 // exception/pc/handler information. 34 35 class ExceptionCache : public CHeapObj<mtCode> { 36 friend class VMStructs; 37 private: 38 enum { cache_size = 16 }; 39 Klass* _exception_type; 40 address _pc[cache_size]; 41 address _handler[cache_size]; 42 int _count; 43 ExceptionCache* _next; 44 45 address pc_at(int index) { assert(index >= 0 && index < count(),""); return _pc[index]; } 46 void set_pc_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _pc[index] = a; } 47 address handler_at(int index) { assert(index >= 0 && index < count(),""); return _handler[index]; } 48 void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; } 49 int count() { return _count; } 50 void increment_count() { _count++; } 51 52 public: 53 54 ExceptionCache(Handle exception, address pc, address handler); 55 56 Klass* exception_type() { return _exception_type; } 57 ExceptionCache* next() { return _next; } 58 void set_next(ExceptionCache *ec) { _next = ec; } 59 60 address match(Handle exception, address pc); 61 bool match_exception_with_space(Handle exception) ; 62 address test_address(address addr); 63 bool add_address_and_handler(address addr, address handler) ; 64 }; 65 66 67 // cache pc descs found in earlier inquiries 68 class PcDescCache VALUE_OBJ_CLASS_SPEC { 69 friend class VMStructs; 70 private: 71 enum { cache_size = 4 }; 72 PcDesc* _pc_descs[cache_size]; // last cache_size pc_descs found 73 public: 74 PcDescCache() { debug_only(_pc_descs[0] = NULL); } 75 void reset_to(PcDesc* initial_pc_desc); 76 PcDesc* find_pc_desc(int pc_offset, bool approximate); 77 void add_pc_desc(PcDesc* pc_desc); 78 PcDesc* last_pc_desc() { return _pc_descs[0]; } 79 }; 80 81 82 // nmethods (native methods) are the compiled code versions of Java methods. 83 // 84 // An nmethod contains: 85 // - header (the nmethod structure) 86 // [Relocation] 87 // - relocation information 88 // - constant part (doubles, longs and floats used in nmethod) 89 // - oop table 90 // [Code] 91 // - code body 92 // - exception handler 93 // - stub code 94 // [Debugging information] 95 // - oop array 96 // - data array 97 // - pcs 98 // [Exception handler table] 99 // - handler entry point array 100 // [Implicit Null Pointer exception table] 101 // - implicit null table array 102 103 class Dependencies; 104 class ExceptionHandlerTable; 105 class ImplicitExceptionTable; 106 class AbstractCompiler; 107 class xmlStream; 108 109 class nmethod : public CodeBlob { 110 friend class VMStructs; 111 friend class NMethodSweeper; 112 friend class CodeCache; // scavengable oops 113 private: 114 // Shared fields for all nmethod's 115 Method* _method; 116 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method 117 jmethodID _jmethod_id; // Cache of method()->jmethod_id() 118 119 // To support simple linked-list chaining of nmethods: 120 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head 121 nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods 122 nmethod* _saved_nmethod_link; // from CodeCache::speculatively_disconnect 123 124 static nmethod* volatile _oops_do_mark_nmethods; 125 nmethod* volatile _oops_do_mark_link; 126 127 AbstractCompiler* _compiler; // The compiler which compiled this nmethod 128 129 // offsets for entry points 130 address _entry_point; // entry point with class check 131 address _verified_entry_point; // entry point without class check 132 address _osr_entry_point; // entry point for on stack replacement 133 134 // Offsets for different nmethod parts 135 int _exception_offset; 136 // All deoptee's will resume execution at this location described by 137 // this offset. 138 int _deoptimize_offset; 139 // All deoptee's at a MethodHandle call site will resume execution 140 // at this location described by this offset. 141 int _deoptimize_mh_offset; 142 // Offset of the unwind handler if it exists 143 int _unwind_handler_offset; 144 145 #ifdef HAVE_DTRACE_H 146 int _trap_offset; 147 #endif // def HAVE_DTRACE_H 148 int _consts_offset; 149 int _stub_offset; 150 int _oops_offset; // offset to where embedded oop table begins (inside data) 151 int _metadata_offset; // embedded meta data table 152 int _scopes_data_offset; 153 int _scopes_pcs_offset; 154 int _dependencies_offset; 155 int _handler_table_offset; 156 int _nul_chk_table_offset; 157 int _nmethod_end_offset; 158 159 // location in frame (offset for sp) that deopt can store the original 160 // pc during a deopt. 161 int _orig_pc_offset; 162 163 int _compile_id; // which compilation made this nmethod 164 int _comp_level; // compilation level 165 166 // protected by CodeCache_lock 167 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock) 168 bool _speculatively_disconnected; // Marked for potential unload 169 170 bool _marked_for_reclamation; // Used by NMethodSweeper (set only by sweeper) 171 bool _marked_for_deoptimization; // Used for stack deoptimization 172 173 // used by jvmti to track if an unload event has been posted for this nmethod. 174 bool _unload_reported; 175 176 // set during construction 177 unsigned int _has_unsafe_access:1; // May fault due to unsafe access. 178 unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes? 179 unsigned int _lazy_critical_native:1; // Lazy JNI critical native 180 unsigned int _has_wide_vectors:1; // Preserve wide vectors at safepoints 181 182 // Protected by Patching_lock 183 unsigned char _state; // {alive, not_entrant, zombie, unloaded} 184 185 #ifdef ASSERT 186 bool _oops_are_stale; // indicates that it's no longer safe to access oops section 187 #endif 188 189 enum { alive = 0, 190 not_entrant = 1, // uncommon trap has happened but activations may still exist 191 zombie = 2, 192 unloaded = 3 }; 193 194 195 jbyte _scavenge_root_state; 196 197 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed 198 // and is not made into a zombie. However, once the nmethod is made into 199 // a zombie, it will be locked one final time if CompiledMethodUnload 200 // event processing needs to be done. 201 jint _lock_count; 202 203 // not_entrant method removal. Each mark_sweep pass will update 204 // this mark to current sweep invocation count if it is seen on the 205 // stack. An not_entrant method can be removed when there are no 206 // more activations, i.e., when the _stack_traversal_mark is less than 207 // current sweep traversal index. 208 long _stack_traversal_mark; 209 210 // The _hotness_counter indicates the hotness of a method. The higher 211 // the value the hotter the method. The hotness counter of a nmethod is 212 // set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method 213 // is active while stack scanning (mark_active_nmethods()). The hotness 214 // counter is decreased (by 1) while sweeping. 215 int _hotness_counter; 216 217 ExceptionCache *_exception_cache; 218 PcDescCache _pc_desc_cache; 219 220 // These are used for compiled synchronized native methods to 221 // locate the owner and stack slot for the BasicLock so that we can 222 // properly revoke the bias of the owner if necessary. They are 223 // needed because there is no debug information for compiled native 224 // wrappers and the oop maps are insufficient to allow 225 // frame::retrieve_receiver() to work. Currently they are expected 226 // to be byte offsets from the Java stack pointer for maximum code 227 // sharing between platforms. Note that currently biased locking 228 // will never cause Class instances to be biased but this code 229 // handles the static synchronized case as well. 230 // JVMTI's GetLocalInstance() also uses these offsets to find the receiver 231 // for non-static native wrapper frames. 232 ByteSize _native_receiver_sp_offset; 233 ByteSize _native_basic_lock_sp_offset; 234 235 friend class nmethodLocker; 236 237 // For native wrappers 238 nmethod(Method* method, 239 int nmethod_size, 240 int compile_id, 241 CodeOffsets* offsets, 242 CodeBuffer *code_buffer, 243 int frame_size, 244 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */ 245 ByteSize basic_lock_sp_offset, /* synchronized natives only */ 246 OopMapSet* oop_maps); 247 248 #ifdef HAVE_DTRACE_H 249 // For native wrappers 250 nmethod(Method* method, 251 int nmethod_size, 252 CodeOffsets* offsets, 253 CodeBuffer *code_buffer, 254 int frame_size); 255 #endif // def HAVE_DTRACE_H 256 257 // Creation support 258 nmethod(Method* method, 259 int nmethod_size, 260 int compile_id, 261 int entry_bci, 262 CodeOffsets* offsets, 263 int orig_pc_offset, 264 DebugInformationRecorder *recorder, 265 Dependencies* dependencies, 266 CodeBuffer *code_buffer, 267 int frame_size, 268 OopMapSet* oop_maps, 269 ExceptionHandlerTable* handler_table, 270 ImplicitExceptionTable* nul_chk_table, 271 AbstractCompiler* compiler, 272 int comp_level); 273 274 // helper methods 275 void* operator new(size_t size, int nmethod_size); 276 277 const char* reloc_string_for(u_char* begin, u_char* end); 278 // Returns true if this thread changed the state of the nmethod or 279 // false if another thread performed the transition. 280 bool make_not_entrant_or_zombie(unsigned int state); 281 void inc_decompile_count(); 282 283 // Used to manipulate the exception cache 284 void add_exception_cache_entry(ExceptionCache* new_entry); 285 ExceptionCache* exception_cache_entry_for_exception(Handle exception); 286 287 // Inform external interfaces that a compiled method has been unloaded 288 void post_compiled_method_unload(); 289 290 // Initailize fields to their default values 291 void init_defaults(); 292 293 public: 294 // create nmethod with entry_bci 295 static nmethod* new_nmethod(methodHandle method, 296 int compile_id, 297 int entry_bci, 298 CodeOffsets* offsets, 299 int orig_pc_offset, 300 DebugInformationRecorder* recorder, 301 Dependencies* dependencies, 302 CodeBuffer *code_buffer, 303 int frame_size, 304 OopMapSet* oop_maps, 305 ExceptionHandlerTable* handler_table, 306 ImplicitExceptionTable* nul_chk_table, 307 AbstractCompiler* compiler, 308 int comp_level); 309 310 static nmethod* new_native_nmethod(methodHandle method, 311 int compile_id, 312 CodeBuffer *code_buffer, 313 int vep_offset, 314 int frame_complete, 315 int frame_size, 316 ByteSize receiver_sp_offset, 317 ByteSize basic_lock_sp_offset, 318 OopMapSet* oop_maps); 319 320 #ifdef HAVE_DTRACE_H 321 // The method we generate for a dtrace probe has to look 322 // like an nmethod as far as the rest of the system is concerned 323 // which is somewhat unfortunate. 324 static nmethod* new_dtrace_nmethod(methodHandle method, 325 CodeBuffer *code_buffer, 326 int vep_offset, 327 int trap_offset, 328 int frame_complete, 329 int frame_size); 330 331 int trap_offset() const { return _trap_offset; } 332 address trap_address() const { return insts_begin() + _trap_offset; } 333 334 #endif // def HAVE_DTRACE_H 335 336 // accessors 337 Method* method() const { return _method; } 338 AbstractCompiler* compiler() const { return _compiler; } 339 340 // type info 341 bool is_nmethod() const { return true; } 342 bool is_java_method() const { return !method()->is_native(); } 343 bool is_native_method() const { return method()->is_native(); } 344 bool is_osr_method() const { return _entry_bci != InvocationEntryBci; } 345 346 bool is_compiled_by_c1() const; 347 bool is_compiled_by_c2() const; 348 bool is_compiled_by_shark() const; 349 350 // boundaries for different parts 351 address consts_begin () const { return header_begin() + _consts_offset ; } 352 address consts_end () const { return header_begin() + code_offset() ; } 353 address insts_begin () const { return header_begin() + code_offset() ; } 354 address insts_end () const { return header_begin() + _stub_offset ; } 355 address stub_begin () const { return header_begin() + _stub_offset ; } 356 address stub_end () const { return header_begin() + _oops_offset ; } 357 address exception_begin () const { return header_begin() + _exception_offset ; } 358 address deopt_handler_begin () const { return header_begin() + _deoptimize_offset ; } 359 address deopt_mh_handler_begin() const { return header_begin() + _deoptimize_mh_offset ; } 360 address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; } 361 oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; } 362 oop* oops_end () const { return (oop*) (header_begin() + _metadata_offset) ; } 363 364 Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; } 365 Metadata** metadata_end () const { return (Metadata**) (header_begin() + _scopes_data_offset) ; } 366 367 address scopes_data_begin () const { return header_begin() + _scopes_data_offset ; } 368 address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; } 369 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); } 370 PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; } 371 address dependencies_begin () const { return header_begin() + _dependencies_offset ; } 372 address dependencies_end () const { return header_begin() + _handler_table_offset ; } 373 address handler_table_begin () const { return header_begin() + _handler_table_offset ; } 374 address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; } 375 address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; } 376 address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; } 377 378 // Sizes 379 int consts_size () const { return consts_end () - consts_begin (); } 380 int insts_size () const { return insts_end () - insts_begin (); } 381 int stub_size () const { return stub_end () - stub_begin (); } 382 int oops_size () const { return (address) oops_end () - (address) oops_begin (); } 383 int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); } 384 int scopes_data_size () const { return scopes_data_end () - scopes_data_begin (); } 385 int scopes_pcs_size () const { return (intptr_t) scopes_pcs_end () - (intptr_t) scopes_pcs_begin (); } 386 int dependencies_size () const { return dependencies_end () - dependencies_begin (); } 387 int handler_table_size() const { return handler_table_end() - handler_table_begin(); } 388 int nul_chk_table_size() const { return nul_chk_table_end() - nul_chk_table_begin(); } 389 390 int total_size () const; 391 392 // Hotness counter accessor methods 393 void dec_hotness_counter(int val) { _hotness_counter-= val; } 394 void set_hotness_counter(int val) { _hotness_counter = val; } 395 int get_hotness_counter() const { return _hotness_counter; } 396 397 // Containment 398 bool consts_contains (address addr) const { return consts_begin () <= addr && addr < consts_end (); } 399 bool insts_contains (address addr) const { return insts_begin () <= addr && addr < insts_end (); } 400 bool stub_contains (address addr) const { return stub_begin () <= addr && addr < stub_end (); } 401 bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); } 402 bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); } 403 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); } 404 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); } 405 bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); } 406 bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); } 407 408 // entry points 409 address entry_point() const { return _entry_point; } // normal entry point 410 address verified_entry_point() const { return _verified_entry_point; } // if klass is correct 411 412 // flag accessing and manipulation 413 bool is_in_use() const { return _state == alive; } 414 bool is_alive() const { return _state == alive || _state == not_entrant; } 415 bool is_not_entrant() const { return _state == not_entrant; } 416 bool is_zombie() const { return _state == zombie; } 417 bool is_unloaded() const { return _state == unloaded; } 418 419 // Make the nmethod non entrant. The nmethod will continue to be 420 // alive. It is used when an uncommon trap happens. Returns true 421 // if this thread changed the state of the nmethod or false if 422 // another thread performed the transition. 423 bool make_not_entrant() { return make_not_entrant_or_zombie(not_entrant); } 424 bool make_zombie() { return make_not_entrant_or_zombie(zombie); } 425 426 // used by jvmti to track if the unload event has been reported 427 bool unload_reported() { return _unload_reported; } 428 void set_unload_reported() { _unload_reported = true; } 429 430 bool is_marked_for_deoptimization() const { return _marked_for_deoptimization; } 431 void mark_for_deoptimization() { _marked_for_deoptimization = true; } 432 433 void make_unloaded(BoolObjectClosure* is_alive, oop cause); 434 435 bool has_dependencies() { return dependencies_size() != 0; } 436 void flush_dependencies(BoolObjectClosure* is_alive); 437 bool has_flushed_dependencies() { return _has_flushed_dependencies; } 438 void set_has_flushed_dependencies() { 439 assert(!has_flushed_dependencies(), "should only happen once"); 440 _has_flushed_dependencies = 1; 441 } 442 443 bool is_marked_for_reclamation() const { return _marked_for_reclamation; } 444 void mark_for_reclamation() { _marked_for_reclamation = 1; } 445 446 bool has_unsafe_access() const { return _has_unsafe_access; } 447 void set_has_unsafe_access(bool z) { _has_unsafe_access = z; } 448 449 bool has_method_handle_invokes() const { return _has_method_handle_invokes; } 450 void set_has_method_handle_invokes(bool z) { _has_method_handle_invokes = z; } 451 452 bool is_speculatively_disconnected() const { return _speculatively_disconnected; } 453 void set_speculatively_disconnected(bool z) { _speculatively_disconnected = z; } 454 455 bool is_lazy_critical_native() const { return _lazy_critical_native; } 456 void set_lazy_critical_native(bool z) { _lazy_critical_native = z; } 457 458 bool has_wide_vectors() const { return _has_wide_vectors; } 459 void set_has_wide_vectors(bool z) { _has_wide_vectors = z; } 460 461 int comp_level() const { return _comp_level; } 462 463 // Support for oops in scopes and relocs: 464 // Note: index 0 is reserved for null. 465 oop oop_at(int index) const { return index == 0 ? (oop) NULL: *oop_addr_at(index); } 466 oop* oop_addr_at(int index) const { // for GC 467 // relocation indexes are biased by 1 (because 0 is reserved) 468 assert(index > 0 && index <= oops_size(), "must be a valid non-zero index"); 469 assert(!_oops_are_stale, "oops are stale"); 470 return &oops_begin()[index - 1]; 471 } 472 473 // Support for meta data in scopes and relocs: 474 // Note: index 0 is reserved for null. 475 Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); } 476 Metadata** metadata_addr_at(int index) const { // for GC 477 // relocation indexes are biased by 1 (because 0 is reserved) 478 assert(index > 0 && index <= metadata_size(), "must be a valid non-zero index"); 479 return &metadata_begin()[index - 1]; 480 } 481 482 void copy_values(GrowableArray<jobject>* oops); 483 void copy_values(GrowableArray<Metadata*>* metadata); 484 485 // Relocation support 486 private: 487 void fix_oop_relocations(address begin, address end, bool initialize_immediates); 488 inline void initialize_immediate_oop(oop* dest, jobject handle); 489 490 public: 491 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); } 492 void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); } 493 void verify_oop_relocations(); 494 495 bool is_at_poll_return(address pc); 496 bool is_at_poll_or_poll_return(address pc); 497 498 // Scavengable oop support 499 bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; } 500 protected: 501 enum { sl_on_list = 0x01, sl_marked = 0x10 }; 502 void set_on_scavenge_root_list() { _scavenge_root_state = sl_on_list; } 503 void clear_on_scavenge_root_list() { _scavenge_root_state = 0; } 504 // assertion-checking and pruning logic uses the bits of _scavenge_root_state 505 #ifndef PRODUCT 506 void set_scavenge_root_marked() { _scavenge_root_state |= sl_marked; } 507 void clear_scavenge_root_marked() { _scavenge_root_state &= ~sl_marked; } 508 bool scavenge_root_not_marked() { return (_scavenge_root_state &~ sl_on_list) == 0; } 509 // N.B. there is no positive marked query, and we only use the not_marked query for asserts. 510 #endif //PRODUCT 511 nmethod* scavenge_root_link() const { return _scavenge_root_link; } 512 void set_scavenge_root_link(nmethod *n) { _scavenge_root_link = n; } 513 514 nmethod* saved_nmethod_link() const { return _saved_nmethod_link; } 515 void set_saved_nmethod_link(nmethod *n) { _saved_nmethod_link = n; } 516 517 public: 518 519 // Sweeper support 520 long stack_traversal_mark() { return _stack_traversal_mark; } 521 void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; } 522 523 // Exception cache support 524 ExceptionCache* exception_cache() const { return _exception_cache; } 525 void set_exception_cache(ExceptionCache *ec) { _exception_cache = ec; } 526 address handler_for_exception_and_pc(Handle exception, address pc); 527 void add_handler_for_exception_and_pc(Handle exception, address pc, address handler); 528 void remove_from_exception_cache(ExceptionCache* ec); 529 530 // implicit exceptions support 531 address continuation_for_implicit_exception(address pc); 532 533 // On-stack replacement support 534 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; } 535 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; } 536 void invalidate_osr_method(); 537 nmethod* osr_link() const { return _osr_link; } 538 void set_osr_link(nmethod *n) { _osr_link = n; } 539 540 // tells whether frames described by this nmethod can be deoptimized 541 // note: native wrappers cannot be deoptimized. 542 bool can_be_deoptimized() const { return is_java_method(); } 543 544 // Inline cache support 545 void clear_inline_caches(); 546 void cleanup_inline_caches(); 547 bool inlinecache_check_contains(address addr) const { 548 return (addr >= code_begin() && addr < verified_entry_point()); 549 } 550 551 // Check that all metadata is still alive 552 void verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive); 553 554 // unlink and deallocate this nmethod 555 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not 556 // expected to use any other private methods/data in this class. 557 558 protected: 559 void flush(); 560 561 public: 562 // When true is returned, it is unsafe to remove this nmethod even if 563 // it is a zombie, since the VM or the ServiceThread might still be 564 // using it. 565 bool is_locked_by_vm() const { return _lock_count >0; } 566 567 // See comment at definition of _last_seen_on_stack 568 void mark_as_seen_on_stack(); 569 bool can_not_entrant_be_converted(); 570 571 // Evolution support. We make old (discarded) compiled methods point to new Method*s. 572 void set_method(Method* method) { _method = method; } 573 574 // GC support 575 void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred); 576 bool can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred); 577 578 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, 579 OopClosure* f); 580 void oops_do(OopClosure* f) { oops_do(f, false); } 581 void oops_do(OopClosure* f, bool allow_zombie); 582 bool detect_scavenge_root_oops(); 583 void verify_scavenge_root_oops() PRODUCT_RETURN; 584 585 bool test_set_oops_do_mark(); 586 static void oops_do_marking_prologue(); 587 static void oops_do_marking_epilogue(); 588 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; } 589 bool test_oops_do_mark() { return _oops_do_mark_link != NULL; } 590 591 // ScopeDesc for an instruction 592 ScopeDesc* scope_desc_at(address pc); 593 594 private: 595 ScopeDesc* scope_desc_in(address begin, address end); 596 597 address* orig_pc_addr(const frame* fr) { return (address*) ((address)fr->unextended_sp() + _orig_pc_offset); } 598 599 PcDesc* find_pc_desc_internal(address pc, bool approximate); 600 601 PcDesc* find_pc_desc(address pc, bool approximate) { 602 PcDesc* desc = _pc_desc_cache.last_pc_desc(); 603 if (desc != NULL && desc->pc_offset() == pc - code_begin()) { 604 return desc; 605 } 606 return find_pc_desc_internal(pc, approximate); 607 } 608 609 public: 610 // ScopeDesc retrieval operation 611 PcDesc* pc_desc_at(address pc) { return find_pc_desc(pc, false); } 612 // pc_desc_near returns the first PcDesc at or after the givne pc. 613 PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); } 614 615 public: 616 // copying of debugging information 617 void copy_scopes_pcs(PcDesc* pcs, int count); 618 void copy_scopes_data(address buffer, int size); 619 620 // Deopt 621 // Return true is the PC is one would expect if the frame is being deopted. 622 bool is_deopt_pc (address pc) { return is_deopt_entry(pc) || is_deopt_mh_entry(pc); } 623 bool is_deopt_entry (address pc) { return pc == deopt_handler_begin(); } 624 bool is_deopt_mh_entry(address pc) { return pc == deopt_mh_handler_begin(); } 625 // Accessor/mutator for the original pc of a frame before a frame was deopted. 626 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); } 627 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; } 628 629 static address get_deopt_original_pc(const frame* fr); 630 631 // MethodHandle 632 bool is_method_handle_return(address return_pc); 633 634 // jvmti support: 635 void post_compiled_method_load_event(); 636 jmethodID get_and_cache_jmethod_id(); 637 638 // verify operations 639 void verify(); 640 void verify_scopes(); 641 void verify_interrupt_point(address interrupt_point); 642 643 // printing support 644 void print() const; 645 void print_code(); 646 void print_relocations() PRODUCT_RETURN; 647 void print_pcs() PRODUCT_RETURN; 648 void print_scopes() PRODUCT_RETURN; 649 void print_dependencies() PRODUCT_RETURN; 650 void print_value_on(outputStream* st) const PRODUCT_RETURN; 651 void print_calls(outputStream* st) PRODUCT_RETURN; 652 void print_handler_table() PRODUCT_RETURN; 653 void print_nul_chk_table() PRODUCT_RETURN; 654 void print_nmethod(bool print_code); 655 656 // need to re-define this from CodeBlob else the overload hides it 657 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); } 658 void print_on(outputStream* st, const char* msg) const; 659 660 // Logging 661 void log_identity(xmlStream* log) const; 662 void log_new_nmethod() const; 663 void log_state_change() const; 664 665 // Prints block-level comments, including nmethod specific block labels: 666 virtual void print_block_comment(outputStream* stream, address block_begin) const { 667 print_nmethod_labels(stream, block_begin); 668 CodeBlob::print_block_comment(stream, block_begin); 669 } 670 void print_nmethod_labels(outputStream* stream, address block_begin) const; 671 672 // Prints a comment for one native instruction (reloc info, pc desc) 673 void print_code_comment_on(outputStream* st, int column, address begin, address end); 674 static void print_statistics() PRODUCT_RETURN; 675 676 // Compiler task identification. Note that all OSR methods 677 // are numbered in an independent sequence if CICountOSR is true, 678 // and native method wrappers are also numbered independently if 679 // CICountNative is true. 680 int compile_id() const { return _compile_id; } 681 const char* compile_kind() const; 682 683 // For debugging 684 // CompiledIC* IC_at(char* p) const; 685 // PrimitiveIC* primitiveIC_at(char* p) const; 686 oop embeddedOop_at(address p); 687 688 // tells if any of this method's dependencies have been invalidated 689 // (this is expensive!) 690 bool check_all_dependencies(); 691 692 // tells if this compiled method is dependent on the given changes, 693 // and the changes have invalidated it 694 bool check_dependency_on(DepChange& changes); 695 696 // Evolution support. Tells if this compiled method is dependent on any of 697 // methods m() of class dependee, such that if m() in dependee is replaced, 698 // this compiled method will have to be deoptimized. 699 bool is_evol_dependent_on(Klass* dependee); 700 701 // Fast breakpoint support. Tells if this compiled method is 702 // dependent on the given method. Returns true if this nmethod 703 // corresponds to the given method as well. 704 bool is_dependent_on_method(Method* dependee); 705 706 // is it ok to patch at address? 707 bool is_patchable_at(address instr_address); 708 709 // UseBiasedLocking support 710 ByteSize native_receiver_sp_offset() { 711 return _native_receiver_sp_offset; 712 } 713 ByteSize native_basic_lock_sp_offset() { 714 return _native_basic_lock_sp_offset; 715 } 716 717 // support for code generation 718 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); } 719 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); } 720 static int entry_bci_offset() { return offset_of(nmethod, _entry_bci); } 721 722 // RedefineClasses support. Mark metadata in nmethods as on_stack so that 723 // redefine classes doesn't purge it. 724 static void mark_on_stack(nmethod* nm) { 725 nm->metadata_do(Metadata::mark_on_stack); 726 } 727 void metadata_do(void f(Metadata*)); 728 }; 729 730 // Locks an nmethod so its code will not get removed and it will not 731 // be made into a zombie, even if it is a not_entrant method. After the 732 // nmethod becomes a zombie, if CompiledMethodUnload event processing 733 // needs to be done, then lock_nmethod() is used directly to keep the 734 // generated code from being reused too early. 735 class nmethodLocker : public StackObj { 736 nmethod* _nm; 737 738 public: 739 740 // note: nm can be NULL 741 // Only JvmtiDeferredEvent::compiled_method_unload_event() 742 // should pass zombie_ok == true. 743 static void lock_nmethod(nmethod* nm, bool zombie_ok = false); 744 static void unlock_nmethod(nmethod* nm); // (ditto) 745 746 nmethodLocker(address pc); // derive nm from pc 747 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); } 748 nmethodLocker() { _nm = NULL; } 749 ~nmethodLocker() { unlock_nmethod(_nm); } 750 751 nmethod* code() { return _nm; } 752 void set_code(nmethod* new_nm) { 753 unlock_nmethod(_nm); // note: This works even if _nm==new_nm. 754 _nm = new_nm; 755 lock_nmethod(_nm); 756 } 757 }; 758 759 #endif // SHARE_VM_CODE_NMETHOD_HPP