1 /*
2 * Copyright (c) 1997, 2019, 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_CODE_NMETHOD_HPP
26 #define SHARE_CODE_NMETHOD_HPP
27
28 #include "code/compiledMethod.hpp"
29
30 class DepChange;
31 class DirectiveSet;
32 class DebugInformationRecorder;
33
34 // nmethods (native methods) are the compiled code versions of Java methods.
35 //
36 // An nmethod contains:
37 // - header (the nmethod structure)
38 // [Relocation]
39 // - relocation information
40 // - constant part (doubles, longs and floats used in nmethod)
41 // - oop table
42 // [Code]
43 // - code body
44 // - exception handler
45 // - stub code
46 // [Debugging information]
47 // - oop array
48 // - data array
49 // - pcs
50 // [Exception handler table]
51 // - handler entry point array
52 // [Implicit Null Pointer exception table]
53 // - implicit null table array
54 // [Speculations]
55 // - encoded speculations array
56 // [JVMCINMethodData]
57 // - meta data for JVMCI compiled nmethod
58
59 #if INCLUDE_JVMCI
60 class FailedSpeculation;
61 class JVMCINMethodData;
62 #endif
63
64 class nmethod : public CompiledMethod {
65 friend class VMStructs;
66 friend class JVMCIVMStructs;
67 friend class NMethodSweeper;
68 friend class CodeCache; // scavengable oops
69 friend class JVMCINMethodData;
70 private:
71
72 // Shared fields for all nmethod's
73 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
74 jmethodID _jmethod_id; // Cache of method()->jmethod_id()
75
76 // To support simple linked-list chaining of nmethods:
77 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
78
79 static nmethod* volatile _oops_do_mark_nmethods;
80 nmethod* volatile _oops_do_mark_link;
81
82 // offsets for entry points
83 address _entry_point; // entry point with class check
84 address _verified_entry_point; // entry point without class check
85 address _osr_entry_point; // entry point for on stack replacement
86
87 // Offsets for different nmethod parts
88 int _exception_offset;
89 // Offset of the unwind handler if it exists
90 int _unwind_handler_offset;
91
92 int _consts_offset;
93 int _stub_offset;
94 int _oops_offset; // offset to where embedded oop table begins (inside data)
95 int _metadata_offset; // embedded meta data table
96 int _scopes_data_offset;
97 int _scopes_pcs_offset;
98 int _dependencies_offset;
99 int _handler_table_offset;
100 int _nul_chk_table_offset;
101 #if INCLUDE_JVMCI
102 int _speculations_offset;
103 int _jvmci_data_offset;
104 #endif
105 int _nmethod_end_offset;
106
107 int code_offset() const { return (address) code_begin() - header_begin(); }
108
109 // location in frame (offset for sp) that deopt can store the original
110 // pc during a deopt.
111 int _orig_pc_offset;
112
113 int _compile_id; // which compilation made this nmethod
114 int _comp_level; // compilation level
115
116 // protected by CodeCache_lock
117 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
118
119 // used by jvmti to track if an unload event has been posted for this nmethod.
120 bool _unload_reported;
121
122 // Protected by Patching_lock
123 volatile signed char _state; // {not_installed, in_use, not_entrant, zombie, unloaded}
124
125 #ifdef ASSERT
126 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
127 #endif
128
129 #if INCLUDE_RTM_OPT
130 // RTM state at compile time. Used during deoptimization to decide
131 // whether to restart collecting RTM locking abort statistic again.
132 RTMState _rtm_state;
133 #endif
134
135 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed
136 // and is not made into a zombie. However, once the nmethod is made into
137 // a zombie, it will be locked one final time if CompiledMethodUnload
138 // event processing needs to be done.
139 volatile jint _lock_count;
140
141 // not_entrant method removal. Each mark_sweep pass will update
142 // this mark to current sweep invocation count if it is seen on the
143 // stack. An not_entrant method can be removed when there are no
144 // more activations, i.e., when the _stack_traversal_mark is less than
145 // current sweep traversal index.
146 volatile long _stack_traversal_mark;
147
148 // The _hotness_counter indicates the hotness of a method. The higher
149 // the value the hotter the method. The hotness counter of a nmethod is
150 // set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
151 // is active while stack scanning (mark_active_nmethods()). The hotness
152 // counter is decreased (by 1) while sweeping.
153 int _hotness_counter;
154
155 // Local state used to keep track of whether unloading is happening or not
156 volatile uint8_t _is_unloading_state;
157
158 // These are used for compiled synchronized native methods to
159 // locate the owner and stack slot for the BasicLock so that we can
160 // properly revoke the bias of the owner if necessary. They are
161 // needed because there is no debug information for compiled native
162 // wrappers and the oop maps are insufficient to allow
163 // frame::retrieve_receiver() to work. Currently they are expected
164 // to be byte offsets from the Java stack pointer for maximum code
165 // sharing between platforms. Note that currently biased locking
166 // will never cause Class instances to be biased but this code
167 // handles the static synchronized case as well.
168 // JVMTI's GetLocalInstance() also uses these offsets to find the receiver
169 // for non-static native wrapper frames.
170 ByteSize _native_receiver_sp_offset;
171 ByteSize _native_basic_lock_sp_offset;
172
173 friend class nmethodLocker;
174
175 // For native wrappers
176 nmethod(Method* method,
177 CompilerType type,
178 int nmethod_size,
179 int compile_id,
180 CodeOffsets* offsets,
181 CodeBuffer *code_buffer,
182 int frame_size,
183 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
184 ByteSize basic_lock_sp_offset, /* synchronized natives only */
185 OopMapSet* oop_maps);
186
187 // Creation support
188 nmethod(Method* method,
189 CompilerType type,
190 int nmethod_size,
191 int compile_id,
192 int entry_bci,
193 CodeOffsets* offsets,
194 int orig_pc_offset,
195 DebugInformationRecorder *recorder,
196 Dependencies* dependencies,
197 CodeBuffer *code_buffer,
198 int frame_size,
199 OopMapSet* oop_maps,
200 ExceptionHandlerTable* handler_table,
201 ImplicitExceptionTable* nul_chk_table,
202 AbstractCompiler* compiler,
203 int comp_level
204 #if INCLUDE_JVMCI
205 , char* speculations,
206 int speculations_len,
207 int jvmci_data_size
208 #endif
209 );
210
211 // helper methods
212 void* operator new(size_t size, int nmethod_size, int comp_level) throw();
213
214 const char* reloc_string_for(u_char* begin, u_char* end);
215
216 bool try_transition(int new_state);
217
218 // Returns true if this thread changed the state of the nmethod or
219 // false if another thread performed the transition.
220 bool make_not_entrant_or_zombie(int state);
221 bool make_entrant() { Unimplemented(); return false; }
222 void inc_decompile_count();
223
224 // Inform external interfaces that a compiled method has been unloaded
225 void post_compiled_method_unload();
226
227 // Initailize fields to their default values
228 void init_defaults();
229
230 // Offsets
231 int content_offset() const { return content_begin() - header_begin(); }
232 int data_offset() const { return _data_offset; }
233
234 address header_end() const { return (address) header_begin() + header_size(); }
235
236 public:
237 // create nmethod with entry_bci
238 static nmethod* new_nmethod(const methodHandle& method,
239 int compile_id,
240 int entry_bci,
241 CodeOffsets* offsets,
242 int orig_pc_offset,
243 DebugInformationRecorder* recorder,
244 Dependencies* dependencies,
245 CodeBuffer *code_buffer,
246 int frame_size,
247 OopMapSet* oop_maps,
248 ExceptionHandlerTable* handler_table,
249 ImplicitExceptionTable* nul_chk_table,
250 AbstractCompiler* compiler,
251 int comp_level
252 #if INCLUDE_JVMCI
253 , char* speculations = NULL,
254 int speculations_len = 0,
255 int nmethod_mirror_index = -1,
256 const char* nmethod_mirror_name = NULL,
257 FailedSpeculation** failed_speculations = NULL
258 #endif
259 );
260
261 // Only used for unit tests.
262 nmethod()
263 : CompiledMethod(),
264 _is_unloading_state(0),
265 _native_receiver_sp_offset(in_ByteSize(-1)),
266 _native_basic_lock_sp_offset(in_ByteSize(-1)) {}
267
268
269 static nmethod* new_native_nmethod(const methodHandle& method,
270 int compile_id,
271 CodeBuffer *code_buffer,
272 int vep_offset,
273 int frame_complete,
274 int frame_size,
275 ByteSize receiver_sp_offset,
276 ByteSize basic_lock_sp_offset,
277 OopMapSet* oop_maps);
278
279 // type info
280 bool is_nmethod() const { return true; }
281 bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
282
283 // boundaries for different parts
284 address consts_begin () const { return header_begin() + _consts_offset ; }
285 address consts_end () const { return code_begin() ; }
286 address stub_begin () const { return header_begin() + _stub_offset ; }
287 address stub_end () const { return header_begin() + _oops_offset ; }
288 address exception_begin () const { return header_begin() + _exception_offset ; }
289 address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; }
290 oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; }
291 oop* oops_end () const { return (oop*) (header_begin() + _metadata_offset) ; }
292
293 Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
294 Metadata** metadata_end () const { return (Metadata**) _scopes_data_begin; }
295
296 address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
297 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
298 PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; }
299 address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
300 address dependencies_end () const { return header_begin() + _handler_table_offset ; }
301 address handler_table_begin () const { return header_begin() + _handler_table_offset ; }
302 address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
303 address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; }
304 #if INCLUDE_JVMCI
305 address nul_chk_table_end () const { return header_begin() + _speculations_offset ; }
306 address speculations_begin () const { return header_begin() + _speculations_offset ; }
307 address speculations_end () const { return header_begin() + _jvmci_data_offset ; }
308 address jvmci_data_begin () const { return header_begin() + _jvmci_data_offset ; }
309 address jvmci_data_end () const { return header_begin() + _nmethod_end_offset ; }
310 #else
311 address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
312 #endif
313
314 // Sizes
315 int oops_size () const { return (address) oops_end () - (address) oops_begin (); }
316 int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); }
317 int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
318 #if INCLUDE_JVMCI
319 int speculations_size () const { return speculations_end () - speculations_begin (); }
320 int jvmci_data_size () const { return jvmci_data_end () - jvmci_data_begin (); }
321 #endif
322
323 int oops_count() const { assert(oops_size() % oopSize == 0, ""); return (oops_size() / oopSize) + 1; }
324 int metadata_count() const { assert(metadata_size() % wordSize == 0, ""); return (metadata_size() / wordSize) + 1; }
325
326 int total_size () const;
327
328 void dec_hotness_counter() { _hotness_counter--; }
329 void set_hotness_counter(int val) { _hotness_counter = val; }
330 int hotness_counter() const { return _hotness_counter; }
331
332 // Containment
333 bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
334 bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); }
335 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
336 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
337
338 // entry points
339 address entry_point() const { return _entry_point; } // normal entry point
340 address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
341
342 // flag accessing and manipulation
343 bool is_not_installed() const { return _state == not_installed; }
344 bool is_in_use() const { return _state <= in_use; }
345 bool is_alive() const { return _state < unloaded; }
346 bool is_not_entrant() const { return _state == not_entrant; }
347 bool is_zombie() const { return _state == zombie; }
348 bool is_unloaded() const { return _state == unloaded; }
349
350 void clear_unloading_state();
351 virtual bool is_unloading();
352 virtual void do_unloading(bool unloading_occurred);
353
354 #if INCLUDE_RTM_OPT
355 // rtm state accessing and manipulating
356 RTMState rtm_state() const { return _rtm_state; }
357 void set_rtm_state(RTMState state) { _rtm_state = state; }
358 #endif
359
360 void make_in_use() { _state = in_use; }
361 // Make the nmethod non entrant. The nmethod will continue to be
362 // alive. It is used when an uncommon trap happens. Returns true
363 // if this thread changed the state of the nmethod or false if
364 // another thread performed the transition.
365 bool make_not_entrant() {
366 assert(!method()->is_method_handle_intrinsic(), "Cannot make MH intrinsic not entrant");
367 return make_not_entrant_or_zombie(not_entrant);
368 }
369 bool make_not_used() { return make_not_entrant(); }
370 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
371
372 // used by jvmti to track if the unload event has been reported
373 bool unload_reported() { return _unload_reported; }
374 void set_unload_reported() { _unload_reported = true; }
375
376 int get_state() const {
377 return _state;
378 }
379
380 void make_unloaded();
381
382 bool has_dependencies() { return dependencies_size() != 0; }
383 void print_dependencies() PRODUCT_RETURN;
384 void flush_dependencies(bool delete_immediately);
385 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
386 void set_has_flushed_dependencies() {
387 assert(!has_flushed_dependencies(), "should only happen once");
388 _has_flushed_dependencies = 1;
389 }
390
391 int comp_level() const { return _comp_level; }
392
393 void unlink_from_method(bool acquire_lock);
394
395 // Support for oops in scopes and relocs:
396 // Note: index 0 is reserved for null.
397 oop oop_at(int index) const;
398 oop oop_at_phantom(int index) const; // phantom reference
399 oop* oop_addr_at(int index) const { // for GC
400 // relocation indexes are biased by 1 (because 0 is reserved)
401 assert(index > 0 && index <= oops_count(), "must be a valid non-zero index");
402 assert(!_oops_are_stale, "oops are stale");
403 return &oops_begin()[index - 1];
404 }
405
406 // Support for meta data in scopes and relocs:
407 // Note: index 0 is reserved for null.
408 Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
409 Metadata** metadata_addr_at(int index) const { // for GC
410 // relocation indexes are biased by 1 (because 0 is reserved)
411 assert(index > 0 && index <= metadata_count(), "must be a valid non-zero index");
412 return &metadata_begin()[index - 1];
413 }
414
415 void copy_values(GrowableArray<jobject>* oops);
416 void copy_values(GrowableArray<Metadata*>* metadata);
417
418 // Relocation support
419 private:
420 void fix_oop_relocations(address begin, address end, bool initialize_immediates);
421 inline void initialize_immediate_oop(oop* dest, jobject handle);
422
423 public:
424 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
425 void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); }
426
427 // Sweeper support
428 long stack_traversal_mark() { return _stack_traversal_mark; }
429 void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
430
431 // On-stack replacement support
432 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
433 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
434 void invalidate_osr_method();
435 nmethod* osr_link() const { return _osr_link; }
436 void set_osr_link(nmethod *n) { _osr_link = n; }
437
438 // Verify calls to dead methods have been cleaned.
439 void verify_clean_inline_caches();
440
441 // unlink and deallocate this nmethod
442 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
443 // expected to use any other private methods/data in this class.
444
445 protected:
446 void flush();
447
448 public:
449 // When true is returned, it is unsafe to remove this nmethod even if
450 // it is a zombie, since the VM or the ServiceThread might still be
451 // using it.
452 bool is_locked_by_vm() const { return _lock_count >0; }
453
454 // See comment at definition of _last_seen_on_stack
455 void mark_as_seen_on_stack();
456 bool can_convert_to_zombie();
457
458 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
459 void set_method(Method* method) { _method = method; }
460
461 #if INCLUDE_JVMCI
462 // Gets the JVMCI name of this nmethod.
463 const char* jvmci_name();
464
465 // Records the pending failed speculation in the
466 // JVMCI speculation log associated with this nmethod.
467 void update_speculation(JavaThread* thread);
468
469 // Gets the data specific to a JVMCI compiled method.
470 // This returns a non-NULL value iff this nmethod was
471 // compiled by the JVMCI compiler.
472 JVMCINMethodData* jvmci_nmethod_data() const {
473 return jvmci_data_size() == 0 ? NULL : (JVMCINMethodData*) jvmci_data_begin();
474 }
475 #endif
476
477 public:
478 void oops_do(OopClosure* f) { oops_do(f, false); }
479 void oops_do(OopClosure* f, bool allow_dead);
480
481 bool test_set_oops_do_mark();
482 static void oops_do_marking_prologue();
483 static void oops_do_marking_epilogue();
484 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
485 bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }
486
487 private:
488 ScopeDesc* scope_desc_in(address begin, address end);
489
490 address* orig_pc_addr(const frame* fr);
491
492 public:
493 // copying of debugging information
494 void copy_scopes_pcs(PcDesc* pcs, int count);
495 void copy_scopes_data(address buffer, int size);
496
497 // Accessor/mutator for the original pc of a frame before a frame was deopted.
498 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
499 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
500
501 // jvmti support:
502 void post_compiled_method_load_event();
503 jmethodID get_and_cache_jmethod_id();
504
505 // verify operations
506 void verify();
507 void verify_scopes();
508 void verify_interrupt_point(address interrupt_point);
509
510 // Disassemble this nmethod with additional debug information, e.g. information about blocks.
511 void decode2(outputStream* st) const;
512 void print_constant_pool(outputStream* st);
513
514 // Avoid hiding of parent's 'decode(outputStream*)' method.
515 void decode(outputStream* st) const { decode2(st); } // just delegate here.
516
517 // printing support
518 void print() const;
519 void print(outputStream* st) const;
520 void print_code();
521
522 #if defined(SUPPORT_DATA_STRUCTS)
523 // print output in opt build for disassembler library
524 void print_relocations() PRODUCT_RETURN;
525 void print_pcs() { print_pcs_on(tty); }
526 void print_pcs_on(outputStream* st);
527 void print_scopes() { print_scopes_on(tty); }
528 void print_scopes_on(outputStream* st) PRODUCT_RETURN;
529 void print_value_on(outputStream* st) const;
530 void print_handler_table();
531 void print_nul_chk_table();
532 void print_recorded_oops();
533 void print_recorded_metadata();
534
535 void print_oops(outputStream* st); // oops from the underlying CodeBlob.
536 void print_metadata(outputStream* st); // metadata in metadata pool.
537 #else
538 // void print_pcs() PRODUCT_RETURN;
539 void print_pcs() { return; }
540 #endif
541
542 void print_calls(outputStream* st) PRODUCT_RETURN;
543 static void print_statistics() PRODUCT_RETURN;
544
545 void maybe_print_nmethod(DirectiveSet* directive);
546 void print_nmethod(bool print_code);
547
548 // need to re-define this from CodeBlob else the overload hides it
549 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
550 void print_on(outputStream* st, const char* msg) const;
551
552 // Logging
553 void log_identity(xmlStream* log) const;
554 void log_new_nmethod() const;
555 void log_state_change() const;
556
557 // Prints block-level comments, including nmethod specific block labels:
558 virtual void print_block_comment(outputStream* stream, address block_begin) const {
559 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
560 print_nmethod_labels(stream, block_begin);
561 CodeBlob::print_block_comment(stream, block_begin);
562 #endif
563 }
564 bool has_block_comment(address block_begin) {
565 return CodeBlob::has_block_comment(block_begin);
566 }
567 void print_nmethod_labels(outputStream* stream, address block_begin, bool print_section_labels=true) const;
568 const char* nmethod_section_label(address pos) const;
569
570 // returns whether this nmethod has code comments.
571 bool has_code_comment(address begin, address end);
572 // Prints a comment for one native instruction (reloc info, pc desc)
573 void print_code_comment_on(outputStream* st, int column, address begin, address end);
574
575 // Compiler task identification. Note that all OSR methods
576 // are numbered in an independent sequence if CICountOSR is true,
577 // and native method wrappers are also numbered independently if
578 // CICountNative is true.
579 virtual int compile_id() const { return _compile_id; }
580 const char* compile_kind() const;
581
582 // tells if any of this method's dependencies have been invalidated
583 // (this is expensive!)
584 static void check_all_dependencies(DepChange& changes);
585
586 // tells if this compiled method is dependent on the given changes,
587 // and the changes have invalidated it
588 bool check_dependency_on(DepChange& changes);
589
590 // Fast breakpoint support. Tells if this compiled method is
591 // dependent on the given method. Returns true if this nmethod
592 // corresponds to the given method as well.
593 virtual bool is_dependent_on_method(Method* dependee);
594
595 // is it ok to patch at address?
596 bool is_patchable_at(address instr_address);
597
598 // UseBiasedLocking support
599 ByteSize native_receiver_sp_offset() {
600 return _native_receiver_sp_offset;
601 }
602 ByteSize native_basic_lock_sp_offset() {
603 return _native_basic_lock_sp_offset;
604 }
605
606 // support for code generation
607 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
608 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
609 static int state_offset() { return offset_of(nmethod, _state); }
610
611 virtual void metadata_do(MetadataClosure* f);
612
613 NativeCallWrapper* call_wrapper_at(address call) const;
614 NativeCallWrapper* call_wrapper_before(address return_pc) const;
615 address call_instruction_address(address pc) const;
616
617 virtual CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) const;
618 virtual CompiledStaticCall* compiledStaticCall_at(address addr) const;
619 virtual CompiledStaticCall* compiledStaticCall_before(address addr) const;
620 };
621
622 // Locks an nmethod so its code will not get removed and it will not
623 // be made into a zombie, even if it is a not_entrant method. After the
624 // nmethod becomes a zombie, if CompiledMethodUnload event processing
625 // needs to be done, then lock_nmethod() is used directly to keep the
626 // generated code from being reused too early.
627 class nmethodLocker : public StackObj {
628 CompiledMethod* _nm;
629
630 public:
631
632 // note: nm can be NULL
633 // Only JvmtiDeferredEvent::compiled_method_unload_event()
634 // should pass zombie_ok == true.
635 static void lock_nmethod(CompiledMethod* nm, bool zombie_ok = false);
636 static void unlock_nmethod(CompiledMethod* nm); // (ditto)
637
638 nmethodLocker(address pc); // derive nm from pc
639 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
640 nmethodLocker(CompiledMethod *nm) {
641 _nm = nm;
642 lock(_nm);
643 }
644
645 static void lock(CompiledMethod* method) {
646 if (method == NULL) return;
647 lock_nmethod(method);
648 }
649
650 static void unlock(CompiledMethod* method) {
651 if (method == NULL) return;
652 unlock_nmethod(method);
653 }
654
655 nmethodLocker() { _nm = NULL; }
656 ~nmethodLocker() {
657 unlock(_nm);
658 }
659
660 CompiledMethod* code() { return _nm; }
661 void set_code(CompiledMethod* new_nm) {
662 unlock(_nm); // note: This works even if _nm==new_nm.
663 _nm = new_nm;
664 lock(_nm);
665 }
666 };
667
668 #endif // SHARE_CODE_NMETHOD_HPP