1 /*
2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 // This class is used internally by nmethods, to cache
26 // exception/pc/handler information.
27
28 class ExceptionCache : public CHeapObj {
29 friend class VMStructs;
30 private:
31 static address _unwind_handler;
32 enum { cache_size = 16 };
33 klassOop _exception_type;
34 address _pc[cache_size];
35 address _handler[cache_size];
36 int _count;
37 ExceptionCache* _next;
38
39 address pc_at(int index) { assert(index >= 0 && index < count(),""); return _pc[index]; }
40 void set_pc_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
41 address handler_at(int index) { assert(index >= 0 && index < count(),""); return _handler[index]; }
42 void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
43 int count() { return _count; }
44 void increment_count() { _count++; }
45
46 public:
47
48 ExceptionCache(Handle exception, address pc, address handler);
49
50 klassOop exception_type() { return _exception_type; }
51 klassOop* exception_type_addr() { return &_exception_type; }
52 ExceptionCache* next() { return _next; }
53 void set_next(ExceptionCache *ec) { _next = ec; }
54
55 address match(Handle exception, address pc);
56 bool match_exception_with_space(Handle exception) ;
57 address test_address(address addr);
58 bool add_address_and_handler(address addr, address handler) ;
59
60 static address unwind_handler() { return _unwind_handler; }
61 };
62
63
64 // cache pc descs found in earlier inquiries
65 class PcDescCache VALUE_OBJ_CLASS_SPEC {
66 friend class VMStructs;
67 private:
68 enum { cache_size = 4 };
69 PcDesc* _last_pc_desc; // most recent pc_desc found
70 PcDesc* _pc_descs[cache_size]; // last cache_size pc_descs found
71 public:
72 PcDescCache() { debug_only(_last_pc_desc = NULL); }
73 void reset_to(PcDesc* initial_pc_desc);
74 PcDesc* find_pc_desc(int pc_offset, bool approximate);
75 void add_pc_desc(PcDesc* pc_desc);
76 PcDesc* last_pc_desc() { return _last_pc_desc; }
77 };
78
79
80 // nmethods (native methods) are the compiled code versions of Java methods.
81
82 struct nmFlags {
83 friend class VMStructs;
84 unsigned int version:8; // version number (0 = first version)
85 unsigned int level:4; // optimization level
86 unsigned int age:4; // age (in # of sweep steps)
87
88 unsigned int state:2; // {alive, zombie, unloaded)
89
90 unsigned int isUncommonRecompiled:1; // recompiled because of uncommon trap?
91 unsigned int isToBeRecompiled:1; // to be recompiled as soon as it matures
92 unsigned int hasFlushedDependencies:1; // Used for maintenance of dependencies
93 unsigned int markedForReclamation:1; // Used by NMethodSweeper
94
95 unsigned int has_unsafe_access:1; // May fault due to unsafe access.
96
97 void clear();
98 };
99
100
101 // A nmethod contains:
102 // - header (the nmethod structure)
103 // [Relocation]
104 // - relocation information
105 // - constant part (doubles, longs and floats used in nmethod)
106 // [Code]
107 // - code body
108 // - exception handler
109 // - stub code
110 // [Debugging information]
111 // - oop array
112 // - data array
113 // - pcs
114 // [Exception handler table]
115 // - handler entry point array
116 // [Implicit Null Pointer exception table]
117 // - implicit null table array
118
119 class Dependencies;
120 class ExceptionHandlerTable;
121 class ImplicitExceptionTable;
122 class AbstractCompiler;
123 class xmlStream;
124
125 class nmethod : public CodeBlob {
126 friend class VMStructs;
127 friend class NMethodSweeper;
128 friend class CodeCache; // non-perm oops
129 private:
130 // Shared fields for all nmethod's
131 static int _zombie_instruction_size;
132
133 methodOop _method;
134 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
135
136 // To support simple linked-list chaining of nmethods:
137 nmethod* _osr_link; // from instanceKlass::osr_nmethods_head
138 nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods
139
140 static nmethod* volatile _oops_do_mark_nmethods;
141 nmethod* volatile _oops_do_mark_link;
142
143 AbstractCompiler* _compiler; // The compiler which compiled this nmethod
144
145 // Offsets for different nmethod parts
146 int _exception_offset;
147 // All deoptee's will resume execution at this location described by this offset
148 int _deoptimize_offset;
149 #ifdef HAVE_DTRACE_H
150 int _trap_offset;
151 #endif // def HAVE_DTRACE_H
152 int _stub_offset;
153 int _consts_offset;
154 int _scopes_data_offset;
155 int _scopes_pcs_offset;
156 int _dependencies_offset;
157 int _handler_table_offset;
158 int _nul_chk_table_offset;
159 int _nmethod_end_offset;
160
161 // location in frame (offset for sp) that deopt can store the original
162 // pc during a deopt.
163 int _orig_pc_offset;
164
165 int _compile_id; // which compilation made this nmethod
166 int _comp_level; // compilation level
167
168 // offsets for entry points
169 address _entry_point; // entry point with class check
170 address _verified_entry_point; // entry point without class check
171 address _osr_entry_point; // entry point for on stack replacement
172
173 nmFlags flags; // various flags to keep track of nmethod state
174 bool _markedForDeoptimization; // Used for stack deoptimization
175 enum { alive = 0,
176 not_entrant = 1, // uncommon trap has happened but activations may still exist
177 zombie = 2,
178 unloaded = 3 };
179
180 // used by jvmti to track if an unload event has been posted for this nmethod.
181 bool _unload_reported;
182
183 jbyte _scavenge_root_state;
184
185 NOT_PRODUCT(bool _has_debug_info; )
186
187 // Nmethod Flushing lock (if non-zero, then the nmethod is not removed)
188 jint _lock_count;
189
190 // not_entrant method removal. Each mark_sweep pass will update
191 // this mark to current sweep invocation count if it is seen on the
192 // stack. An not_entrant method can be removed when there is no
193 // more activations, i.e., when the _stack_traversal_mark is less than
194 // current sweep traversal index.
195 long _stack_traversal_mark;
196
197 ExceptionCache *_exception_cache;
198 PcDescCache _pc_desc_cache;
199
200 // These are only used for compiled synchronized native methods to
201 // locate the owner and stack slot for the BasicLock so that we can
202 // properly revoke the bias of the owner if necessary. They are
203 // needed because there is no debug information for compiled native
204 // wrappers and the oop maps are insufficient to allow
205 // frame::retrieve_receiver() to work. Currently they are expected
206 // to be byte offsets from the Java stack pointer for maximum code
207 // sharing between platforms. Note that currently biased locking
208 // will never cause Class instances to be biased but this code
209 // handles the static synchronized case as well.
210 ByteSize _compiled_synchronized_native_basic_lock_owner_sp_offset;
211 ByteSize _compiled_synchronized_native_basic_lock_sp_offset;
212
213 friend class nmethodLocker;
214
215 // For native wrappers
216 nmethod(methodOop method,
217 int nmethod_size,
218 CodeOffsets* offsets,
219 CodeBuffer *code_buffer,
220 int frame_size,
221 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
222 ByteSize basic_lock_sp_offset, /* synchronized natives only */
223 OopMapSet* oop_maps);
224
225 #ifdef HAVE_DTRACE_H
226 // For native wrappers
227 nmethod(methodOop method,
228 int nmethod_size,
229 CodeOffsets* offsets,
230 CodeBuffer *code_buffer,
231 int frame_size);
232 #endif // def HAVE_DTRACE_H
233
234 // Creation support
235 nmethod(methodOop method,
236 int nmethod_size,
237 int compile_id,
238 int entry_bci,
239 CodeOffsets* offsets,
240 int orig_pc_offset,
241 DebugInformationRecorder *recorder,
242 Dependencies* dependencies,
243 CodeBuffer *code_buffer,
244 int frame_size,
245 OopMapSet* oop_maps,
246 ExceptionHandlerTable* handler_table,
247 ImplicitExceptionTable* nul_chk_table,
248 AbstractCompiler* compiler,
249 int comp_level);
250
251 // helper methods
252 void* operator new(size_t size, int nmethod_size);
253
254 const char* reloc_string_for(u_char* begin, u_char* end);
255 void make_not_entrant_or_zombie(int state);
256 void inc_decompile_count();
257
258 // used to check that writes to nmFlags are done consistently.
259 static void check_safepoint() PRODUCT_RETURN;
260
261 // Used to manipulate the exception cache
262 void add_exception_cache_entry(ExceptionCache* new_entry);
263 ExceptionCache* exception_cache_entry_for_exception(Handle exception);
264
265 // Inform external interfaces that a compiled method has been unloaded
266 inline void post_compiled_method_unload();
267
268 public:
269 // create nmethod with entry_bci
270 static nmethod* new_nmethod(methodHandle method,
271 int compile_id,
272 int entry_bci,
273 CodeOffsets* offsets,
274 int orig_pc_offset,
275 DebugInformationRecorder* recorder,
276 Dependencies* dependencies,
277 CodeBuffer *code_buffer,
278 int frame_size,
279 OopMapSet* oop_maps,
280 ExceptionHandlerTable* handler_table,
281 ImplicitExceptionTable* nul_chk_table,
282 AbstractCompiler* compiler,
283 int comp_level);
284
285 static nmethod* new_native_nmethod(methodHandle method,
286 CodeBuffer *code_buffer,
287 int vep_offset,
288 int frame_complete,
289 int frame_size,
290 ByteSize receiver_sp_offset,
291 ByteSize basic_lock_sp_offset,
292 OopMapSet* oop_maps);
293
294 #ifdef HAVE_DTRACE_H
295 // The method we generate for a dtrace probe has to look
296 // like an nmethod as far as the rest of the system is concerned
297 // which is somewhat unfortunate.
298 static nmethod* new_dtrace_nmethod(methodHandle method,
299 CodeBuffer *code_buffer,
300 int vep_offset,
301 int trap_offset,
302 int frame_complete,
303 int frame_size);
304
305 int trap_offset() const { return _trap_offset; }
306 address trap_address() const { return code_begin() + _trap_offset; }
307
308 #endif // def HAVE_DTRACE_H
309
310 // accessors
311 methodOop method() const { return _method; }
312 AbstractCompiler* compiler() const { return _compiler; }
313
314 #ifndef PRODUCT
315 bool has_debug_info() const { return _has_debug_info; }
316 void set_has_debug_info(bool f) { _has_debug_info = false; }
317 #endif // NOT PRODUCT
318
319 // type info
320 bool is_nmethod() const { return true; }
321 bool is_java_method() const { return !method()->is_native(); }
322 bool is_native_method() const { return method()->is_native(); }
323 bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
324
325 bool is_compiled_by_c1() const;
326 bool is_compiled_by_c2() const;
327
328 // boundaries for different parts
329 address code_begin () const { return _entry_point; }
330 address code_end () const { return header_begin() + _stub_offset ; }
331 address exception_begin () const { return header_begin() + _exception_offset ; }
332 address deopt_handler_begin() const { return header_begin() + _deoptimize_offset ; }
333 address stub_begin () const { return header_begin() + _stub_offset ; }
334 address stub_end () const { return header_begin() + _consts_offset ; }
335 address consts_begin () const { return header_begin() + _consts_offset ; }
336 address consts_end () const { return header_begin() + _scopes_data_offset ; }
337 address scopes_data_begin () const { return header_begin() + _scopes_data_offset ; }
338 address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
339 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
340 PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset); }
341 address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
342 address dependencies_end () const { return header_begin() + _handler_table_offset ; }
343 address handler_table_begin() const { return header_begin() + _handler_table_offset ; }
344 address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
345 address nul_chk_table_begin() const { return header_begin() + _nul_chk_table_offset ; }
346 address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
347
348 int code_size () const { return code_end () - code_begin (); }
349 int stub_size () const { return stub_end () - stub_begin (); }
350 int consts_size () const { return consts_end () - consts_begin (); }
351 int scopes_data_size () const { return scopes_data_end () - scopes_data_begin (); }
352 int scopes_pcs_size () const { return (intptr_t)scopes_pcs_end () - (intptr_t)scopes_pcs_begin (); }
353 int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
354 int handler_table_size() const { return handler_table_end() - handler_table_begin(); }
355 int nul_chk_table_size() const { return nul_chk_table_end() - nul_chk_table_begin(); }
356
357 int total_size () const;
358
359 bool code_contains (address addr) const { return code_begin () <= addr && addr < code_end (); }
360 bool stub_contains (address addr) const { return stub_begin () <= addr && addr < stub_end (); }
361 bool consts_contains (address addr) const { return consts_begin () <= addr && addr < consts_end (); }
362 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
363 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
364 bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
365 bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
366
367 // entry points
368 address entry_point() const { return _entry_point; } // normal entry point
369 address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
370
371 // flag accessing and manipulation
372 bool is_in_use() const { return flags.state == alive; }
373 bool is_alive() const { return flags.state == alive || flags.state == not_entrant; }
374 bool is_not_entrant() const { return flags.state == not_entrant; }
375 bool is_zombie() const { return flags.state == zombie; }
376 bool is_unloaded() const { return flags.state == unloaded; }
377
378 // Make the nmethod non entrant. The nmethod will continue to be alive.
379 // It is used when an uncommon trap happens.
380 void make_not_entrant() { make_not_entrant_or_zombie(not_entrant); }
381 void make_zombie() { make_not_entrant_or_zombie(zombie); }
382
383 // used by jvmti to track if the unload event has been reported
384 bool unload_reported() { return _unload_reported; }
385 void set_unload_reported() { _unload_reported = true; }
386
387 bool is_marked_for_deoptimization() const { return _markedForDeoptimization; }
388 void mark_for_deoptimization() { _markedForDeoptimization = true; }
389
390 void make_unloaded(BoolObjectClosure* is_alive, oop cause);
391
392 bool has_dependencies() { return dependencies_size() != 0; }
393 void flush_dependencies(BoolObjectClosure* is_alive);
394 bool has_flushed_dependencies() { return flags.hasFlushedDependencies; }
395 void set_has_flushed_dependencies() {
396 check_safepoint();
397 assert(!has_flushed_dependencies(), "should only happen once");
398 flags.hasFlushedDependencies = 1;
399 }
400
401 bool is_marked_for_reclamation() const { return flags.markedForReclamation; }
402 void mark_for_reclamation() { check_safepoint(); flags.markedForReclamation = 1; }
403 void unmark_for_reclamation() { check_safepoint(); flags.markedForReclamation = 0; }
404
405 bool has_unsafe_access() const { return flags.has_unsafe_access; }
406 void set_has_unsafe_access(bool z) { flags.has_unsafe_access = z; }
407
408 int level() const { return flags.level; }
409 void set_level(int newLevel) { check_safepoint(); flags.level = newLevel; }
410
411 int comp_level() const { return _comp_level; }
412
413 int version() const { return flags.version; }
414 void set_version(int v);
415
416 // Non-perm oop support
417 bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; }
418 protected:
419 enum { npl_on_list = 0x01, npl_marked = 0x10 };
420 void set_on_scavenge_root_list() { _scavenge_root_state = npl_on_list; }
421 void clear_on_scavenge_root_list() { _scavenge_root_state = 0; }
422 // assertion-checking and pruning logic uses the bits of _scavenge_root_state
423 #ifndef PRODUCT
424 void set_scavenge_root_marked() { _scavenge_root_state |= npl_marked; }
425 void clear_scavenge_root_marked() { _scavenge_root_state &= ~npl_marked; }
426 bool scavenge_root_not_marked() { return (_scavenge_root_state &~ npl_on_list) == 0; }
427 // N.B. there is no positive marked query, and we only use the not_marked query for asserts.
428 #endif //PRODUCT
429 nmethod* scavenge_root_link() const { return _scavenge_root_link; }
430 void set_scavenge_root_link(nmethod *n) { _scavenge_root_link = n; }
431
432 public:
433
434 // Sweeper support
435 long stack_traversal_mark() { return _stack_traversal_mark; }
436 void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
437
438 // Exception cache support
439 ExceptionCache* exception_cache() const { return _exception_cache; }
440 void set_exception_cache(ExceptionCache *ec) { _exception_cache = ec; }
441 address handler_for_exception_and_pc(Handle exception, address pc);
442 void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
443 void remove_from_exception_cache(ExceptionCache* ec);
444
445 // implicit exceptions support
446 address continuation_for_implicit_exception(address pc);
447
448 // On-stack replacement support
449 int osr_entry_bci() const { assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod"); return _entry_bci; }
450 address osr_entry() const { assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod"); return _osr_entry_point; }
451 void invalidate_osr_method();
452 nmethod* osr_link() const { return _osr_link; }
453 void set_osr_link(nmethod *n) { _osr_link = n; }
454
455 // tells whether frames described by this nmethod can be deoptimized
456 // note: native wrappers cannot be deoptimized.
457 bool can_be_deoptimized() const { return is_java_method(); }
458
459 // Inline cache support
460 void clear_inline_caches();
461 void cleanup_inline_caches();
462 bool inlinecache_check_contains(address addr) const {
463 return (addr >= instructions_begin() && addr < verified_entry_point());
464 }
465
466 // unlink and deallocate this nmethod
467 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
468 // expected to use any other private methods/data in this class.
469
470 protected:
471 void flush();
472
473 public:
474 // If returning true, it is unsafe to remove this nmethod even though it is a zombie
475 // nmethod, since the VM might have a reference to it. Should only be called from a safepoint.
476 bool is_locked_by_vm() const { return _lock_count >0; }
477
478 // See comment at definition of _last_seen_on_stack
479 void mark_as_seen_on_stack();
480 bool can_not_entrant_be_converted();
481
482 // Evolution support. We make old (discarded) compiled methods point to new methodOops.
483 void set_method(methodOop method) { _method = method; }
484
485 // GC support
486 void do_unloading(BoolObjectClosure* is_alive, OopClosure* keep_alive,
487 bool unloading_occurred);
488 bool can_unload(BoolObjectClosure* is_alive, OopClosure* keep_alive,
489 oop* root, bool unloading_occurred);
490
491 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
492 OopClosure* f);
493 virtual void oops_do(OopClosure* f) { oops_do(f, false); }
494 void oops_do(OopClosure* f, bool do_strong_roots_only);
495 bool detect_scavenge_root_oops();
496 void verify_scavenge_root_oops() PRODUCT_RETURN;
497
498 bool test_set_oops_do_mark();
499 static void oops_do_marking_prologue();
500 static void oops_do_marking_epilogue();
501 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
502 DEBUG_ONLY(bool test_oops_do_mark() { return _oops_do_mark_link != NULL; })
503
504 // ScopeDesc for an instruction
505 ScopeDesc* scope_desc_at(address pc);
506
507 private:
508 ScopeDesc* scope_desc_in(address begin, address end);
509
510 address* orig_pc_addr(const frame* fr ) { return (address*) ((address)fr->unextended_sp() + _orig_pc_offset); }
511
512 PcDesc* find_pc_desc_internal(address pc, bool approximate);
513
514 PcDesc* find_pc_desc(address pc, bool approximate) {
515 PcDesc* desc = _pc_desc_cache.last_pc_desc();
516 if (desc != NULL && desc->pc_offset() == pc - instructions_begin()) {
517 return desc;
518 }
519 return find_pc_desc_internal(pc, approximate);
520 }
521
522 public:
523 // ScopeDesc retrieval operation
524 PcDesc* pc_desc_at(address pc) { return find_pc_desc(pc, false); }
525 // pc_desc_near returns the first PcDesc at or after the givne pc.
526 PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
527
528 public:
529 // copying of debugging information
530 void copy_scopes_pcs(PcDesc* pcs, int count);
531 void copy_scopes_data(address buffer, int size);
532
533 // deopt
534 // return true is the pc is one would expect if the frame is being deopted.
535 bool is_deopt_pc(address pc);
536 // Accessor/mutator for the original pc of a frame before a frame was deopted.
537 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
538 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
539
540 // jvmti support:
541 void post_compiled_method_load_event();
542
543 // verify operations
544 void verify();
545 void verify_scopes();
546 void verify_interrupt_point(address interrupt_point);
547
548 // printing support
549 void print() const;
550 void print_code();
551 void print_relocations() PRODUCT_RETURN;
552 void print_pcs() PRODUCT_RETURN;
553 void print_scopes() PRODUCT_RETURN;
554 void print_dependencies() PRODUCT_RETURN;
555 void print_value_on(outputStream* st) const PRODUCT_RETURN;
556 void print_calls(outputStream* st) PRODUCT_RETURN;
557 void print_handler_table() PRODUCT_RETURN;
558 void print_nul_chk_table() PRODUCT_RETURN;
559 void print_nmethod(bool print_code);
560
561 void print_on(outputStream* st, const char* title) const;
562
563 // Logging
564 void log_identity(xmlStream* log) const;
565 void log_new_nmethod() const;
566 void log_state_change(int state) const;
567
568 // Prints a comment for one native instruction (reloc info, pc desc)
569 void print_code_comment_on(outputStream* st, int column, address begin, address end);
570 static void print_statistics() PRODUCT_RETURN;
571
572 // Compiler task identification. Note that all OSR methods
573 // are numbered in an independent sequence if CICountOSR is true,
574 // and native method wrappers are also numbered independently if
575 // CICountNative is true.
576 int compile_id() const { return _compile_id; }
577 const char* compile_kind() const;
578
579 // For debugging
580 // CompiledIC* IC_at(char* p) const;
581 // PrimitiveIC* primitiveIC_at(char* p) const;
582 oop embeddedOop_at(address p);
583
584 // tells if any of this method's dependencies have been invalidated
585 // (this is expensive!)
586 bool check_all_dependencies();
587
588 // tells if this compiled method is dependent on the given changes,
589 // and the changes have invalidated it
590 bool check_dependency_on(DepChange& changes);
591
592 // Evolution support. Tells if this compiled method is dependent on any of
593 // methods m() of class dependee, such that if m() in dependee is replaced,
594 // this compiled method will have to be deoptimized.
595 bool is_evol_dependent_on(klassOop dependee);
596
597 // Fast breakpoint support. Tells if this compiled method is
598 // dependent on the given method. Returns true if this nmethod
599 // corresponds to the given method as well.
600 bool is_dependent_on_method(methodOop dependee);
601
602 // is it ok to patch at address?
603 bool is_patchable_at(address instr_address);
604
605 // UseBiasedLocking support
606 ByteSize compiled_synchronized_native_basic_lock_owner_sp_offset() {
607 return _compiled_synchronized_native_basic_lock_owner_sp_offset;
608 }
609 ByteSize compiled_synchronized_native_basic_lock_sp_offset() {
610 return _compiled_synchronized_native_basic_lock_sp_offset;
611 }
612
613 // support for code generation
614 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
615 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
616 static int entry_bci_offset() { return offset_of(nmethod, _entry_bci); }
617
618 };
619
620 // Locks an nmethod so its code will not get removed, even if it is a zombie/not_entrant method
621 class nmethodLocker : public StackObj {
622 nmethod* _nm;
623
624 static void lock_nmethod(nmethod* nm); // note: nm can be NULL
625 static void unlock_nmethod(nmethod* nm); // (ditto)
626
627 public:
628 nmethodLocker(address pc); // derive nm from pc
629 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
630 nmethodLocker() { _nm = NULL; }
631 ~nmethodLocker() { unlock_nmethod(_nm); }
632
633 nmethod* code() { return _nm; }
634 void set_code(nmethod* new_nm) {
635 unlock_nmethod(_nm); // note: This works even if _nm==new_nm.
636 _nm = new_nm;
637 lock_nmethod(_nm);
638 }
639 };