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 _verified_value_entry_point; // value type entry point without class check
94 address _osr_entry_point; // entry point for on stack replacement
95
96 // Offsets for different nmethod parts
97 int _exception_offset;
98 // Offset of the unwind handler if it exists
99 int _unwind_handler_offset;
100
101 int _consts_offset;
102 int _stub_offset;
103 int _oops_offset; // offset to where embedded oop table begins (inside data)
104 int _metadata_offset; // embedded meta data table
105 int _scopes_data_offset;
106 int _scopes_pcs_offset;
107 int _dependencies_offset;
108 int _handler_table_offset;
109 int _nul_chk_table_offset;
110 int _nmethod_end_offset;
111
112 int code_offset() const { return (address) code_begin() - header_begin(); }
113
114 // location in frame (offset for sp) that deopt can store the original
115 // pc during a deopt.
116 int _orig_pc_offset;
117
118 int _compile_id; // which compilation made this nmethod
119 int _comp_level; // compilation level
120
121 // protected by CodeCache_lock
122 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
123
124 // used by jvmti to track if an unload event has been posted for this nmethod.
125 bool _unload_reported;
126
127 // Protected by Patching_lock
128 volatile signed char _state; // {not_installed, in_use, not_entrant, zombie, unloaded}
129
130 #ifdef ASSERT
131 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
132 #endif
133
134 jbyte _scavenge_root_state;
135
136 #if INCLUDE_RTM_OPT
137 // RTM state at compile time. Used during deoptimization to decide
138 // whether to restart collecting RTM locking abort statistic again.
139 RTMState _rtm_state;
140 #endif
141
142 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed
143 // and is not made into a zombie. However, once the nmethod is made into
144 // a zombie, it will be locked one final time if CompiledMethodUnload
145 // event processing needs to be done.
146 volatile jint _lock_count;
147
148 // not_entrant method removal. Each mark_sweep pass will update
149 // this mark to current sweep invocation count if it is seen on the
150 // stack. An not_entrant method can be removed when there are no
151 // more activations, i.e., when the _stack_traversal_mark is less than
152 // current sweep traversal index.
153 volatile long _stack_traversal_mark;
154
155 // The _hotness_counter indicates the hotness of a method. The higher
156 // the value the hotter the method. The hotness counter of a nmethod is
157 // set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
158 // is active while stack scanning (mark_active_nmethods()). The hotness
159 // counter is decreased (by 1) while sweeping.
160 int _hotness_counter;
161
162 // Local state used to keep track of whether unloading is happening or not
163 volatile uint8_t _is_unloading_state;
164
165 // These are used for compiled synchronized native methods to
166 // locate the owner and stack slot for the BasicLock so that we can
167 // properly revoke the bias of the owner if necessary. They are
168 // needed because there is no debug information for compiled native
169 // wrappers and the oop maps are insufficient to allow
170 // frame::retrieve_receiver() to work. Currently they are expected
171 // to be byte offsets from the Java stack pointer for maximum code
172 // sharing between platforms. Note that currently biased locking
173 // will never cause Class instances to be biased but this code
174 // handles the static synchronized case as well.
175 // JVMTI's GetLocalInstance() also uses these offsets to find the receiver
176 // for non-static native wrapper frames.
177 ByteSize _native_receiver_sp_offset;
178 ByteSize _native_basic_lock_sp_offset;
179
180 friend class nmethodLocker;
181
182 // For native wrappers
183 nmethod(Method* method,
184 CompilerType type,
185 int nmethod_size,
186 int compile_id,
187 CodeOffsets* offsets,
188 CodeBuffer *code_buffer,
189 int frame_size,
190 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
191 ByteSize basic_lock_sp_offset, /* synchronized natives only */
192 OopMapSet* oop_maps);
193
194 // Creation support
195 nmethod(Method* method,
196 CompilerType type,
197 int nmethod_size,
198 int compile_id,
199 int entry_bci,
200 CodeOffsets* offsets,
201 int orig_pc_offset,
202 DebugInformationRecorder *recorder,
203 Dependencies* dependencies,
204 CodeBuffer *code_buffer,
205 int frame_size,
206 OopMapSet* oop_maps,
207 ExceptionHandlerTable* handler_table,
208 ImplicitExceptionTable* nul_chk_table,
209 AbstractCompiler* compiler,
210 int comp_level
211 #if INCLUDE_JVMCI
212 , jweak installed_code,
213 jweak speculation_log
214 #endif
215 );
216
217 // helper methods
218 void* operator new(size_t size, int nmethod_size, int comp_level) throw();
219
220 const char* reloc_string_for(u_char* begin, u_char* end);
221 // Returns true if this thread changed the state of the nmethod or
222 // false if another thread performed the transition.
223 bool make_not_entrant_or_zombie(int state);
224 bool make_entrant() { Unimplemented(); return false; }
225 void inc_decompile_count();
226
227 // Inform external interfaces that a compiled method has been unloaded
228 void post_compiled_method_unload();
229
230 // Initailize fields to their default values
231 void init_defaults();
232
233 // Offsets
234 int content_offset() const { return content_begin() - header_begin(); }
235 int data_offset() const { return _data_offset; }
236
237 address header_end() const { return (address) header_begin() + header_size(); }
238
239 public:
240 // create nmethod with entry_bci
241 static nmethod* new_nmethod(const methodHandle& method,
242 int compile_id,
243 int entry_bci,
244 CodeOffsets* offsets,
245 int orig_pc_offset,
246 DebugInformationRecorder* recorder,
247 Dependencies* dependencies,
248 CodeBuffer *code_buffer,
249 int frame_size,
250 OopMapSet* oop_maps,
251 ExceptionHandlerTable* handler_table,
252 ImplicitExceptionTable* nul_chk_table,
253 AbstractCompiler* compiler,
254 int comp_level
255 #if INCLUDE_JVMCI
256 , jweak installed_code = NULL,
257 jweak speculation_log = NULL
258 #endif
259 );
260
261 static nmethod* new_native_nmethod(const methodHandle& method,
262 int compile_id,
263 CodeBuffer *code_buffer,
264 int vep_offset,
265 int frame_complete,
266 int frame_size,
267 ByteSize receiver_sp_offset,
268 ByteSize basic_lock_sp_offset,
269 OopMapSet* oop_maps);
270
271 // type info
272 bool is_nmethod() const { return true; }
273 bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
274
275 // boundaries for different parts
276 address consts_begin () const { return header_begin() + _consts_offset ; }
277 address consts_end () const { return code_begin() ; }
278 address stub_begin () const { return header_begin() + _stub_offset ; }
279 address stub_end () const { return header_begin() + _oops_offset ; }
280 address exception_begin () const { return header_begin() + _exception_offset ; }
281 address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; }
282 oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; }
283 oop* oops_end () const { return (oop*) (header_begin() + _metadata_offset) ; }
284
285 Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
286 Metadata** metadata_end () const { return (Metadata**) _scopes_data_begin; }
287
288 address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
289 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
290 PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; }
291 address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
292 address dependencies_end () const { return header_begin() + _handler_table_offset ; }
293 address handler_table_begin () const { return header_begin() + _handler_table_offset ; }
294 address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
295 address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; }
296 address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
297
298 // Sizes
299 int oops_size () const { return (address) oops_end () - (address) oops_begin (); }
300 int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); }
301 int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
302
303 int oops_count() const { assert(oops_size() % oopSize == 0, ""); return (oops_size() / oopSize) + 1; }
304 int metadata_count() const { assert(metadata_size() % wordSize == 0, ""); return (metadata_size() / wordSize) + 1; }
305
306 int total_size () const;
307
308 void dec_hotness_counter() { _hotness_counter--; }
309 void set_hotness_counter(int val) { _hotness_counter = val; }
310 int hotness_counter() const { return _hotness_counter; }
311
312 // Containment
313 bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
314 bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); }
315 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
316 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
317
318 // entry points
319 address entry_point() const { return _entry_point; } // normal entry point
320 address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
321 address verified_value_entry_point() const { return _verified_value_entry_point; } // pass value type args as oops
322
323 // flag accessing and manipulation
324 bool is_not_installed() const { return _state == not_installed; }
325 bool is_in_use() const { return _state <= in_use; }
326 bool is_alive() const { return _state < zombie; }
327 bool is_not_entrant() const { return _state == not_entrant; }
328 bool is_zombie() const { return _state == zombie; }
329 bool is_unloaded() const { return _state == unloaded; }
330
331 void clear_unloading_state();
332 virtual bool is_unloading();
333 virtual void do_unloading(bool unloading_occurred);
334
335 #if INCLUDE_RTM_OPT
336 // rtm state accessing and manipulating
337 RTMState rtm_state() const { return _rtm_state; }
338 void set_rtm_state(RTMState state) { _rtm_state = state; }
339 #endif
340
341 void make_in_use() { _state = in_use; }
342 // Make the nmethod non entrant. The nmethod will continue to be
343 // alive. It is used when an uncommon trap happens. Returns true
344 // if this thread changed the state of the nmethod or false if
345 // another thread performed the transition.
346 bool make_not_entrant() {
347 assert(!method()->is_method_handle_intrinsic(), "Cannot make MH intrinsic not entrant");
348 return make_not_entrant_or_zombie(not_entrant);
349 }
350 bool make_not_used() { return make_not_entrant(); }
351 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
352
353 // used by jvmti to track if the unload event has been reported
354 bool unload_reported() { return _unload_reported; }
355 void set_unload_reported() { _unload_reported = true; }
356
357 int get_state() const {
358 return _state;
359 }
360
361 void make_unloaded();
362
363 bool has_dependencies() { return dependencies_size() != 0; }
364 void flush_dependencies(bool delete_immediately);
365 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
366 void set_has_flushed_dependencies() {
367 assert(!has_flushed_dependencies(), "should only happen once");
368 _has_flushed_dependencies = 1;
369 }
370
371 int comp_level() const { return _comp_level; }
372
373 // Support for oops in scopes and relocs:
374 // Note: index 0 is reserved for null.
375 oop oop_at(int index) const;
376 oop* oop_addr_at(int index) const { // for GC
377 // relocation indexes are biased by 1 (because 0 is reserved)
378 assert(index > 0 && index <= oops_count(), "must be a valid non-zero index");
379 assert(!_oops_are_stale, "oops are stale");
380 return &oops_begin()[index - 1];
381 }
382
383 // Support for meta data in scopes and relocs:
384 // Note: index 0 is reserved for null.
385 Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
386 Metadata** metadata_addr_at(int index) const { // for GC
387 // relocation indexes are biased by 1 (because 0 is reserved)
388 assert(index > 0 && index <= metadata_count(), "must be a valid non-zero index");
389 return &metadata_begin()[index - 1];
390 }
391
392 void copy_values(GrowableArray<jobject>* oops);
393 void copy_values(GrowableArray<Metadata*>* metadata);
394
395 // Relocation support
396 private:
397 void fix_oop_relocations(address begin, address end, bool initialize_immediates);
398 inline void initialize_immediate_oop(oop* dest, jobject handle);
399
400 public:
401 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
402 void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); }
403
404 // Scavengable oop support
405 bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; }
406 protected:
407 enum { sl_on_list = 0x01, sl_marked = 0x10 };
408 void set_on_scavenge_root_list() { _scavenge_root_state = sl_on_list; }
409 void clear_on_scavenge_root_list() { _scavenge_root_state = 0; }
410 // assertion-checking and pruning logic uses the bits of _scavenge_root_state
411 #ifndef PRODUCT
412 void set_scavenge_root_marked() { _scavenge_root_state |= sl_marked; }
413 void clear_scavenge_root_marked() { _scavenge_root_state &= ~sl_marked; }
414 bool scavenge_root_not_marked() { return (_scavenge_root_state &~ sl_on_list) == 0; }
415 // N.B. there is no positive marked query, and we only use the not_marked query for asserts.
416 #endif //PRODUCT
417 nmethod* scavenge_root_link() const { return _scavenge_root_link; }
418 void set_scavenge_root_link(nmethod *n) { _scavenge_root_link = n; }
419
420 public:
421
422 // Sweeper support
423 long stack_traversal_mark() { return _stack_traversal_mark; }
424 void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
425
426 // implicit exceptions support
427 address continuation_for_implicit_exception(address pc);
428
429 // On-stack replacement support
430 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
431 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
432 void invalidate_osr_method();
433 nmethod* osr_link() const { return _osr_link; }
434 void set_osr_link(nmethod *n) { _osr_link = n; }
435
436 // Verify calls to dead methods have been cleaned.
437 void verify_clean_inline_caches();
438
439 // unlink and deallocate this nmethod
440 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
441 // expected to use any other private methods/data in this class.
442
443 protected:
444 void flush();
445
446 public:
447 // When true is returned, it is unsafe to remove this nmethod even if
448 // it is a zombie, since the VM or the ServiceThread might still be
449 // using it.
450 bool is_locked_by_vm() const { return _lock_count >0; }
451
452 // See comment at definition of _last_seen_on_stack
453 void mark_as_seen_on_stack();
454 bool can_convert_to_zombie();
455
456 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
457 void set_method(Method* method) { _method = method; }
458
459 #if INCLUDE_JVMCI
460 // Gets the InstalledCode object associated with this nmethod
461 // which may be NULL if this nmethod was not compiled by JVMCI
462 // or the weak reference has been cleared.
463 oop jvmci_installed_code();
464
465 // Copies the value of the name field in the InstalledCode
466 // object (if any) associated with this nmethod into buf.
467 // Returns the value of buf if it was updated otherwise NULL.
468 char* jvmci_installed_code_name(char* buf, size_t buflen) const;
469
470 // Updates the state of the InstalledCode (if any) associated with
471 // this nmethod based on the current value of _state.
472 void maybe_invalidate_installed_code();
473
474 // Deoptimizes the nmethod (if any) in the address field of a given
475 // InstalledCode object. The address field is zeroed upon return.
476 static void invalidate_installed_code(Handle installed_code, TRAPS);
477
478 // Gets the SpeculationLog object associated with this nmethod
479 // which may be NULL if this nmethod was not compiled by JVMCI
480 // or the weak reference has been cleared.
481 oop speculation_log();
482
483 private:
484 // Deletes the weak reference (if any) to the InstalledCode object
485 // associated with this nmethod.
486 void clear_jvmci_installed_code();
487
488 // Deletes the weak reference (if any) to the SpeculationLog object
489 // associated with this nmethod.
490 void clear_speculation_log();
491
492 public:
493 #endif
494
495 public:
496 void oops_do(OopClosure* f) { oops_do(f, false); }
497 void oops_do(OopClosure* f, bool allow_zombie);
498 bool detect_scavenge_root_oops();
499 void verify_scavenge_root_oops() PRODUCT_RETURN;
500
501 bool test_set_oops_do_mark();
502 static void oops_do_marking_prologue();
503 static void oops_do_marking_epilogue();
504 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
505 bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }
506
507 private:
508 ScopeDesc* scope_desc_in(address begin, address end);
509
510 address* orig_pc_addr(const frame* fr);
511
512 public:
513 // copying of debugging information
514 void copy_scopes_pcs(PcDesc* pcs, int count);
515 void copy_scopes_data(address buffer, int size);
516
517 // Accessor/mutator for the original pc of a frame before a frame was deopted.
518 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
519 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
520
521 // jvmti support:
522 void post_compiled_method_load_event();
523 jmethodID get_and_cache_jmethod_id();
524
525 // verify operations
526 void verify();
527 void verify_scopes();
528 void verify_interrupt_point(address interrupt_point);
529
530 // printing support
531 void print() const;
532 void print_relocations() PRODUCT_RETURN;
533 void print_pcs() PRODUCT_RETURN;
534 void print_scopes() PRODUCT_RETURN;
535 void print_dependencies() PRODUCT_RETURN;
536 void print_value_on(outputStream* st) const PRODUCT_RETURN;
537 void print_calls(outputStream* st) PRODUCT_RETURN;
538 void print_handler_table() PRODUCT_RETURN;
539 void print_nul_chk_table() PRODUCT_RETURN;
540 void print_recorded_oops() PRODUCT_RETURN;
541 void print_recorded_metadata() PRODUCT_RETURN;
542
543 void maybe_print_nmethod(DirectiveSet* directive);
544 void print_nmethod(bool print_code);
545
546 // need to re-define this from CodeBlob else the overload hides it
547 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
548 void print_on(outputStream* st, const char* msg) const;
549
550 // Logging
551 void log_identity(xmlStream* log) const;
552 void log_new_nmethod() const;
553 void log_state_change() const;
554
555 // Prints block-level comments, including nmethod specific block labels:
556 virtual void print_block_comment(outputStream* stream, address block_begin) const {
557 print_nmethod_labels(stream, block_begin);
558 CodeBlob::print_block_comment(stream, block_begin);
559 }
560 void print_nmethod_labels(outputStream* stream, address block_begin) const;
561
562 // Prints a comment for one native instruction (reloc info, pc desc)
563 void print_code_comment_on(outputStream* st, int column, address begin, address end);
564 static void print_statistics() PRODUCT_RETURN;
565
566 // Compiler task identification. Note that all OSR methods
567 // are numbered in an independent sequence if CICountOSR is true,
568 // and native method wrappers are also numbered independently if
569 // CICountNative is true.
570 virtual int compile_id() const { return _compile_id; }
571 const char* compile_kind() const;
572
573 // tells if any of this method's dependencies have been invalidated
574 // (this is expensive!)
575 static void check_all_dependencies(DepChange& changes);
576
577 // tells if this compiled method is dependent on the given changes,
578 // and the changes have invalidated it
579 bool check_dependency_on(DepChange& changes);
580
581 // Evolution support. Tells if this compiled method is dependent on any of
582 // methods m() of class dependee, such that if m() in dependee is replaced,
583 // this compiled method will have to be deoptimized.
584 bool is_evol_dependent_on(Klass* dependee);
585
586 // Fast breakpoint support. Tells if this compiled method is
587 // dependent on the given method. Returns true if this nmethod
588 // corresponds to the given method as well.
589 virtual bool is_dependent_on_method(Method* dependee);
590
591 // is it ok to patch at address?
592 bool is_patchable_at(address instr_address);
593
594 // UseBiasedLocking support
595 ByteSize native_receiver_sp_offset() {
596 return _native_receiver_sp_offset;
597 }
598 ByteSize native_basic_lock_sp_offset() {
599 return _native_basic_lock_sp_offset;
600 }
601
602 // support for code generation
603 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
604 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
605 static int state_offset() { return offset_of(nmethod, _state); }
606
607 virtual void metadata_do(void f(Metadata*));
608
609 NativeCallWrapper* call_wrapper_at(address call) const;
610 NativeCallWrapper* call_wrapper_before(address return_pc) const;
611 address call_instruction_address(address pc) const;
612
613 virtual CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) const;
614 virtual CompiledStaticCall* compiledStaticCall_at(address addr) const;
615 virtual CompiledStaticCall* compiledStaticCall_before(address addr) const;
616 };
617
618 // Locks an nmethod so its code will not get removed and it will not
619 // be made into a zombie, even if it is a not_entrant method. After the
620 // nmethod becomes a zombie, if CompiledMethodUnload event processing
621 // needs to be done, then lock_nmethod() is used directly to keep the
622 // generated code from being reused too early.
623 class nmethodLocker : public StackObj {
624 CompiledMethod* _nm;
625
626 public:
627
628 // note: nm can be NULL
629 // Only JvmtiDeferredEvent::compiled_method_unload_event()
630 // should pass zombie_ok == true.
631 static void lock_nmethod(CompiledMethod* nm, bool zombie_ok = false);
632 static void unlock_nmethod(CompiledMethod* nm); // (ditto)
633
634 nmethodLocker(address pc); // derive nm from pc
635 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
636 nmethodLocker(CompiledMethod *nm) {
637 _nm = nm;
638 lock(_nm);
639 }
640
641 static void lock(CompiledMethod* method) {
642 if (method == NULL) return;
643 lock_nmethod(method);
644 }
645
646 static void unlock(CompiledMethod* method) {
647 if (method == NULL) return;
648 unlock_nmethod(method);
649 }
650
651 nmethodLocker() { _nm = NULL; }
652 ~nmethodLocker() {
653 unlock(_nm);
654 }
655
656 CompiledMethod* code() { return _nm; }
657 void set_code(CompiledMethod* new_nm) {
658 unlock(_nm); // note: This works even if _nm==new_nm.
659 _nm = new_nm;
660 lock(_nm);
661 }
662 };
663
664 #endif // SHARE_VM_CODE_NMETHOD_HPP