1 /*
2 * Copyright (c) 1997, 2018, 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_VM_CODE_NMETHOD_HPP
26 #define SHARE_VM_CODE_NMETHOD_HPP
27
28 #include "code/compiledMethod.hpp"
29
30 class DepChange;
31 class DirectiveSet;
32
33 // nmethods (native methods) are the compiled code versions of Java methods.
34 //
35 // An nmethod contains:
36 // - header (the nmethod structure)
37 // [Relocation]
38 // - relocation information
39 // - constant part (doubles, longs and floats used in nmethod)
40 // - oop table
41 // [Code]
42 // - code body
43 // - exception handler
44 // - stub code
45 // [Debugging information]
46 // - oop array
47 // - data array
48 // - pcs
49 // [Exception handler table]
50 // - handler entry point array
51 // [Implicit Null Pointer exception table]
52 // - implicit null table array
53
54 class nmethod : public CompiledMethod {
55 friend class VMStructs;
56 friend class JVMCIVMStructs;
57 friend class NMethodSweeper;
58 friend class CodeCache; // scavengable oops
59 private:
60
61 // Shared fields for all nmethod's
62 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
63 jmethodID _jmethod_id; // Cache of method()->jmethod_id()
64
65 #if INCLUDE_JVMCI
66 // A weak reference to an InstalledCode object associated with
67 // this nmethod.
68 jweak _jvmci_installed_code;
69
70 // A weak reference to a SpeculationLog object associated with
71 // this nmethod.
72 jweak _speculation_log;
73
74 // Determines whether this nmethod is unloaded when the
75 // referent in _jvmci_installed_code is cleared. This
76 // will be false if the referent is initialized to a
77 // HotSpotNMethod object whose isDefault field is true.
78 // That is, installed code other than a "default"
79 // HotSpotNMethod causes nmethod unloading.
80 // This field is ignored once _jvmci_installed_code is NULL.
81 bool _jvmci_installed_code_triggers_invalidation;
82 #endif
83
84 // To support simple linked-list chaining of nmethods:
85 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
86
87 static nmethod* volatile _oops_do_mark_nmethods;
88 nmethod* volatile _oops_do_mark_link;
89
90 // offsets for entry points
91 address _entry_point; // entry point with class check
92 address _verified_entry_point; // entry point without class check
93 address _osr_entry_point; // entry point for on stack replacement
94
95 // Offsets for different nmethod parts
96 int _exception_offset;
97 // Offset of the unwind handler if it exists
98 int _unwind_handler_offset;
99
100 int _consts_offset;
101 int _stub_offset;
102 int _oops_offset; // offset to where embedded oop table begins (inside data)
103 int _metadata_offset; // embedded meta data table
104 int _scopes_data_offset;
105 int _scopes_pcs_offset;
106 int _dependencies_offset;
107 int _handler_table_offset;
108 int _nul_chk_table_offset;
109 int _nmethod_end_offset;
110
111 int code_offset() const { return (address) code_begin() - header_begin(); }
112
113 // location in frame (offset for sp) that deopt can store the original
114 // pc during a deopt.
115 int _orig_pc_offset;
116
117 int _compile_id; // which compilation made this nmethod
118 int _comp_level; // compilation level
119
120 // protected by CodeCache_lock
121 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
122
123 // used by jvmti to track if an unload event has been posted for this nmethod.
124 bool _unload_reported;
125
126 // Protected by Patching_lock
127 volatile signed char _state; // {not_installed, in_use, not_entrant, zombie, unloaded}
128
129 #ifdef ASSERT
130 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
131 #endif
132
133 jbyte _scavenge_root_state;
134
135 #if INCLUDE_RTM_OPT
136 // RTM state at compile time. Used during deoptimization to decide
137 // whether to restart collecting RTM locking abort statistic again.
138 RTMState _rtm_state;
139 #endif
140
141 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed
142 // and is not made into a zombie. However, once the nmethod is made into
143 // a zombie, it will be locked one final time if CompiledMethodUnload
144 // event processing needs to be done.
145 volatile jint _lock_count;
146
147 // not_entrant method removal. Each mark_sweep pass will update
148 // this mark to current sweep invocation count if it is seen on the
149 // stack. An not_entrant method can be removed when there are no
150 // more activations, i.e., when the _stack_traversal_mark is less than
151 // current sweep traversal index.
152 volatile long _stack_traversal_mark;
153
154 // The _hotness_counter indicates the hotness of a method. The higher
155 // the value the hotter the method. The hotness counter of a nmethod is
156 // set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
157 // is active while stack scanning (mark_active_nmethods()). The hotness
158 // counter is decreased (by 1) while sweeping.
159 int _hotness_counter;
160
161 // Local state used to keep track of whether unloading is happening or not
162 volatile uint8_t _is_unloading_state;
163
164 // These are used for compiled synchronized native methods to
165 // locate the owner and stack slot for the BasicLock so that we can
166 // properly revoke the bias of the owner if necessary. They are
167 // needed because there is no debug information for compiled native
168 // wrappers and the oop maps are insufficient to allow
169 // frame::retrieve_receiver() to work. Currently they are expected
170 // to be byte offsets from the Java stack pointer for maximum code
171 // sharing between platforms. Note that currently biased locking
172 // will never cause Class instances to be biased but this code
173 // handles the static synchronized case as well.
174 // JVMTI's GetLocalInstance() also uses these offsets to find the receiver
175 // for non-static native wrapper frames.
176 ByteSize _native_receiver_sp_offset;
177 ByteSize _native_basic_lock_sp_offset;
178
179 friend class nmethodLocker;
180
181 // For native wrappers
182 nmethod(Method* method,
183 CompilerType type,
184 int nmethod_size,
185 int compile_id,
186 CodeOffsets* offsets,
187 CodeBuffer *code_buffer,
188 int frame_size,
189 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
190 ByteSize basic_lock_sp_offset, /* synchronized natives only */
191 OopMapSet* oop_maps);
192
193 // Creation support
194 nmethod(Method* method,
195 CompilerType type,
196 int nmethod_size,
197 int compile_id,
198 int entry_bci,
199 CodeOffsets* offsets,
200 int orig_pc_offset,
201 DebugInformationRecorder *recorder,
202 Dependencies* dependencies,
203 CodeBuffer *code_buffer,
204 int frame_size,
205 OopMapSet* oop_maps,
206 ExceptionHandlerTable* handler_table,
207 ImplicitExceptionTable* nul_chk_table,
208 AbstractCompiler* compiler,
209 int comp_level
210 #if INCLUDE_JVMCI
211 , jweak installed_code,
212 jweak speculation_log
213 #endif
214 );
215
216 // helper methods
217 void* operator new(size_t size, int nmethod_size, int comp_level) throw();
218
219 const char* reloc_string_for(u_char* begin, u_char* end);
220 // Returns true if this thread changed the state of the nmethod or
221 // false if another thread performed the transition.
222 bool make_not_entrant_or_zombie(int state);
223 bool make_entrant() { Unimplemented(); return false; }
224 void inc_decompile_count();
225
226 // Inform external interfaces that a compiled method has been unloaded
227 void post_compiled_method_unload();
228
229 // Initailize fields to their default values
230 void init_defaults();
231
232 // Offsets
233 int content_offset() const { return content_begin() - header_begin(); }
234 int data_offset() const { return _data_offset; }
235
236 address header_end() const { return (address) header_begin() + header_size(); }
237
238 public:
239 // create nmethod with entry_bci
240 static nmethod* new_nmethod(const methodHandle& method,
241 int compile_id,
242 int entry_bci,
243 CodeOffsets* offsets,
244 int orig_pc_offset,
245 DebugInformationRecorder* recorder,
246 Dependencies* dependencies,
247 CodeBuffer *code_buffer,
248 int frame_size,
249 OopMapSet* oop_maps,
250 ExceptionHandlerTable* handler_table,
251 ImplicitExceptionTable* nul_chk_table,
252 AbstractCompiler* compiler,
253 int comp_level
254 #if INCLUDE_JVMCI
255 , jweak installed_code = NULL,
256 jweak speculation_log = NULL
257 #endif
258 );
259
260 static nmethod* new_native_nmethod(const methodHandle& method,
261 int compile_id,
262 CodeBuffer *code_buffer,
263 int vep_offset,
264 int frame_complete,
265 int frame_size,
266 ByteSize receiver_sp_offset,
267 ByteSize basic_lock_sp_offset,
268 OopMapSet* oop_maps);
269
270 // type info
271 bool is_nmethod() const { return true; }
272 bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
273
274 // boundaries for different parts
275 address consts_begin () const { return header_begin() + _consts_offset ; }
276 address consts_end () const { return code_begin() ; }
277 address stub_begin () const { return header_begin() + _stub_offset ; }
278 address stub_end () const { return header_begin() + _oops_offset ; }
279 address exception_begin () const { return header_begin() + _exception_offset ; }
280 address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; }
281 oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; }
282 oop* oops_end () const { return (oop*) (header_begin() + _metadata_offset) ; }
283
284 Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
285 Metadata** metadata_end () const { return (Metadata**) _scopes_data_begin; }
286
287 address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
288 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
289 PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; }
290 address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
291 address dependencies_end () const { return header_begin() + _handler_table_offset ; }
292 address handler_table_begin () const { return header_begin() + _handler_table_offset ; }
293 address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
294 address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; }
295 address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
296
297 // Sizes
298 int oops_size () const { return (address) oops_end () - (address) oops_begin (); }
299 int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); }
300 int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
301
302 int oops_count() const { assert(oops_size() % oopSize == 0, ""); return (oops_size() / oopSize) + 1; }
303 int metadata_count() const { assert(metadata_size() % wordSize == 0, ""); return (metadata_size() / wordSize) + 1; }
304
305 int total_size () const;
306
307 void dec_hotness_counter() { _hotness_counter--; }
308 void set_hotness_counter(int val) { _hotness_counter = val; }
309 int hotness_counter() const { return _hotness_counter; }
310
311 // Containment
312 bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
313 bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); }
314 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
315 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
316
317 // entry points
318 address entry_point() const { return _entry_point; } // normal entry point
319 address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
320
321 // flag accessing and manipulation
322 bool is_not_installed() const { return _state == not_installed; }
323 bool is_in_use() const { return _state <= in_use; }
324 bool is_alive() const { return _state < zombie; }
325 bool is_not_entrant() const { return _state == not_entrant; }
326 bool is_zombie() const { return _state == zombie; }
327 bool is_unloaded() const { return _state == unloaded; }
328
329 void clear_unloading_state();
330 virtual bool is_unloading();
331 virtual void do_unloading(bool unloading_occurred);
332
333 #if INCLUDE_RTM_OPT
334 // rtm state accessing and manipulating
335 RTMState rtm_state() const { return _rtm_state; }
336 void set_rtm_state(RTMState state) { _rtm_state = state; }
337 #endif
338
339 void make_in_use() { _state = in_use; }
340 // Make the nmethod non entrant. The nmethod will continue to be
341 // alive. It is used when an uncommon trap happens. Returns true
342 // if this thread changed the state of the nmethod or false if
343 // another thread performed the transition.
344 bool make_not_entrant() {
345 assert(!method()->is_method_handle_intrinsic(), "Cannot make MH intrinsic not entrant");
346 return make_not_entrant_or_zombie(not_entrant);
347 }
348 bool make_not_used() { return make_not_entrant(); }
349 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
350
351 // used by jvmti to track if the unload event has been reported
352 bool unload_reported() { return _unload_reported; }
353 void set_unload_reported() { _unload_reported = true; }
354
355 int get_state() const {
356 return _state;
357 }
358
359 void make_unloaded();
360
361 bool has_dependencies() { return dependencies_size() != 0; }
362 void flush_dependencies(bool delete_immediately);
363 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
364 void set_has_flushed_dependencies() {
365 assert(!has_flushed_dependencies(), "should only happen once");
366 _has_flushed_dependencies = 1;
367 }
368
369 int comp_level() const { return _comp_level; }
370
371 // Support for oops in scopes and relocs:
372 // Note: index 0 is reserved for null.
373 oop oop_at(int index) const;
374 oop* oop_addr_at(int index) const { // for GC
375 // relocation indexes are biased by 1 (because 0 is reserved)
376 assert(index > 0 && index <= oops_count(), "must be a valid non-zero index");
377 assert(!_oops_are_stale, "oops are stale");
378 return &oops_begin()[index - 1];
379 }
380
381 // Support for meta data in scopes and relocs:
382 // Note: index 0 is reserved for null.
383 Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
384 Metadata** metadata_addr_at(int index) const { // for GC
385 // relocation indexes are biased by 1 (because 0 is reserved)
386 assert(index > 0 && index <= metadata_count(), "must be a valid non-zero index");
387 return &metadata_begin()[index - 1];
388 }
389
390 void copy_values(GrowableArray<jobject>* oops);
391 void copy_values(GrowableArray<Metadata*>* metadata);
392
393 // Relocation support
394 private:
395 void fix_oop_relocations(address begin, address end, bool initialize_immediates);
396 inline void initialize_immediate_oop(oop* dest, jobject handle);
397
398 public:
399 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
400 void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); }
401
402 // Scavengable oop support
403 bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; }
404 protected:
405 enum { sl_on_list = 0x01, sl_marked = 0x10 };
406 void set_on_scavenge_root_list() { _scavenge_root_state = sl_on_list; }
407 void clear_on_scavenge_root_list() { _scavenge_root_state = 0; }
408 // assertion-checking and pruning logic uses the bits of _scavenge_root_state
409 #ifndef PRODUCT
410 void set_scavenge_root_marked() { _scavenge_root_state |= sl_marked; }
411 void clear_scavenge_root_marked() { _scavenge_root_state &= ~sl_marked; }
412 bool scavenge_root_not_marked() { return (_scavenge_root_state &~ sl_on_list) == 0; }
413 // N.B. there is no positive marked query, and we only use the not_marked query for asserts.
414 #endif //PRODUCT
415 nmethod* scavenge_root_link() const { return _scavenge_root_link; }
416 void set_scavenge_root_link(nmethod *n) { _scavenge_root_link = n; }
417
418 public:
419
420 // Sweeper support
421 long stack_traversal_mark() { return _stack_traversal_mark; }
422 void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
423
424 // implicit exceptions support
425 address continuation_for_implicit_exception(address pc);
426
427 // On-stack replacement support
428 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
429 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
430 void invalidate_osr_method();
431 nmethod* osr_link() const { return _osr_link; }
432 void set_osr_link(nmethod *n) { _osr_link = n; }
433
434 // Verify calls to dead methods have been cleaned.
435 void verify_clean_inline_caches();
436
437 // unlink and deallocate this nmethod
438 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
439 // expected to use any other private methods/data in this class.
440
441 protected:
442 void flush();
443
444 public:
445 // When true is returned, it is unsafe to remove this nmethod even if
446 // it is a zombie, since the VM or the ServiceThread might still be
447 // using it.
448 bool is_locked_by_vm() const { return _lock_count >0; }
449
450 // See comment at definition of _last_seen_on_stack
451 void mark_as_seen_on_stack();
452 bool can_convert_to_zombie();
453
454 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
455 void set_method(Method* method) { _method = method; }
456
457 #if INCLUDE_JVMCI
458 // Gets the InstalledCode object associated with this nmethod
459 // which may be NULL if this nmethod was not compiled by JVMCI
460 // or the weak reference has been cleared.
461 oop jvmci_installed_code();
462
463 // Copies the value of the name field in the InstalledCode
464 // object (if any) associated with this nmethod into buf.
465 // Returns the value of buf if it was updated otherwise NULL.
466 char* jvmci_installed_code_name(char* buf, size_t buflen) const;
467
468 // Updates the state of the InstalledCode (if any) associated with
469 // this nmethod based on the current value of _state.
470 void maybe_invalidate_installed_code();
471
472 // Deoptimizes the nmethod (if any) in the address field of a given
473 // InstalledCode object. The address field is zeroed upon return.
474 static void invalidate_installed_code(Handle installed_code, TRAPS);
475
476 // Gets the SpeculationLog object associated with this nmethod
477 // which may be NULL if this nmethod was not compiled by JVMCI
478 // or the weak reference has been cleared.
479 oop speculation_log();
480
481 private:
482 // Deletes the weak reference (if any) to the InstalledCode object
483 // associated with this nmethod.
484 void clear_jvmci_installed_code();
485
486 // Deletes the weak reference (if any) to the SpeculationLog object
487 // associated with this nmethod.
488 void clear_speculation_log();
489
490 public:
491 #endif
492
493 public:
494 void oops_do(OopClosure* f) { oops_do(f, false); }
495 void oops_do(OopClosure* f, bool allow_zombie);
496 bool detect_scavenge_root_oops();
497 void verify_scavenge_root_oops() PRODUCT_RETURN;
498
499 bool test_set_oops_do_mark();
500 static void oops_do_marking_prologue();
501 static void oops_do_marking_epilogue();
502 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
503 bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }
504
505 private:
506 ScopeDesc* scope_desc_in(address begin, address end);
507
508 address* orig_pc_addr(const frame* fr);
509
510 public:
511 // copying of debugging information
512 void copy_scopes_pcs(PcDesc* pcs, int count);
513 void copy_scopes_data(address buffer, int size);
514
515 // Accessor/mutator for the original pc of a frame before a frame was deopted.
516 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
517 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
518
519 // jvmti support:
520 void post_compiled_method_load_event();
521 jmethodID get_and_cache_jmethod_id();
522
523 // verify operations
524 void verify();
525 void verify_scopes();
526 void verify_interrupt_point(address interrupt_point);
527
528 // printing support
529 void print() const;
530 void print_relocations() PRODUCT_RETURN;
531 void print_pcs() PRODUCT_RETURN;
532 void print_scopes() PRODUCT_RETURN;
533 void print_dependencies() PRODUCT_RETURN;
534 void print_value_on(outputStream* st) const PRODUCT_RETURN;
535 void print_calls(outputStream* st) PRODUCT_RETURN;
536 void print_handler_table() PRODUCT_RETURN;
537 void print_nul_chk_table() PRODUCT_RETURN;
538 void print_recorded_oops() PRODUCT_RETURN;
539 void print_recorded_metadata() PRODUCT_RETURN;
540
541 void maybe_print_nmethod(DirectiveSet* directive);
542 void print_nmethod(bool print_code);
543
544 // need to re-define this from CodeBlob else the overload hides it
545 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
546 void print_on(outputStream* st, const char* msg) const;
547
548 // Logging
549 void log_identity(xmlStream* log) const;
550 void log_new_nmethod() const;
551 void log_state_change() const;
552
553 // Prints block-level comments, including nmethod specific block labels:
554 virtual void print_block_comment(outputStream* stream, address block_begin) const {
555 print_nmethod_labels(stream, block_begin);
556 CodeBlob::print_block_comment(stream, block_begin);
557 }
558 void print_nmethod_labels(outputStream* stream, address block_begin) const;
559
560 // Prints a comment for one native instruction (reloc info, pc desc)
561 void print_code_comment_on(outputStream* st, int column, address begin, address end);
562 static void print_statistics() PRODUCT_RETURN;
563
564 // Compiler task identification. Note that all OSR methods
565 // are numbered in an independent sequence if CICountOSR is true,
566 // and native method wrappers are also numbered independently if
567 // CICountNative is true.
568 virtual int compile_id() const { return _compile_id; }
569 const char* compile_kind() const;
570
571 // tells if any of this method's dependencies have been invalidated
572 // (this is expensive!)
573 static void check_all_dependencies(DepChange& changes);
574
575 // tells if this compiled method is dependent on the given changes,
576 // and the changes have invalidated it
577 bool check_dependency_on(DepChange& changes);
578
579 // Evolution support. Tells if this compiled method is dependent on any of
580 // methods m() of class dependee, such that if m() in dependee is replaced,
581 // this compiled method will have to be deoptimized.
582 bool is_evol_dependent_on(Klass* dependee);
583
584 // Fast breakpoint support. Tells if this compiled method is
585 // dependent on the given method. Returns true if this nmethod
586 // corresponds to the given method as well.
587 virtual bool is_dependent_on_method(Method* dependee);
588
589 // is it ok to patch at address?
590 bool is_patchable_at(address instr_address);
591
592 // UseBiasedLocking support
593 ByteSize native_receiver_sp_offset() {
594 return _native_receiver_sp_offset;
595 }
596 ByteSize native_basic_lock_sp_offset() {
597 return _native_basic_lock_sp_offset;
598 }
599
600 // support for code generation
601 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
602 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
603 static int state_offset() { return offset_of(nmethod, _state); }
604
605 virtual void metadata_do(void f(Metadata*));
606
607 NativeCallWrapper* call_wrapper_at(address call) const;
608 NativeCallWrapper* call_wrapper_before(address return_pc) const;
609 address call_instruction_address(address pc) const;
610
611 virtual CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) const;
612 virtual CompiledStaticCall* compiledStaticCall_at(address addr) const;
613 virtual CompiledStaticCall* compiledStaticCall_before(address addr) const;
614 };
615
616 // Locks an nmethod so its code will not get removed and it will not
617 // be made into a zombie, even if it is a not_entrant method. After the
618 // nmethod becomes a zombie, if CompiledMethodUnload event processing
619 // needs to be done, then lock_nmethod() is used directly to keep the
620 // generated code from being reused too early.
621 class nmethodLocker : public StackObj {
622 CompiledMethod* _nm;
623
624 public:
625
626 // note: nm can be NULL
627 // Only JvmtiDeferredEvent::compiled_method_unload_event()
628 // should pass zombie_ok == true.
629 static void lock_nmethod(CompiledMethod* nm, bool zombie_ok = false);
630 static void unlock_nmethod(CompiledMethod* nm); // (ditto)
631
632 nmethodLocker(address pc); // derive nm from pc
633 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
634 nmethodLocker(CompiledMethod *nm) {
635 _nm = nm;
636 lock(_nm);
637 }
638
639 static void lock(CompiledMethod* method) {
640 if (method == NULL) return;
641 lock_nmethod(method);
642 }
643
644 static void unlock(CompiledMethod* method) {
645 if (method == NULL) return;
646 unlock_nmethod(method);
647 }
648
649 nmethodLocker() { _nm = NULL; }
650 ~nmethodLocker() {
651 unlock(_nm);
652 }
653
654 CompiledMethod* code() { return _nm; }
655 void set_code(CompiledMethod* new_nm) {
656 unlock(_nm); // note: This works even if _nm==new_nm.
657 _nm = new_nm;
658 lock(_nm);
659 }
660 };
661
662 #endif // SHARE_VM_CODE_NMETHOD_HPP