1 /*
2 * Copyright (c) 1997, 2022, 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 *
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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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 class JvmtiThreadState;
34
35 // nmethods (native methods) are the compiled code versions of Java methods.
36 //
37 // An nmethod contains:
38 // - header (the nmethod structure)
39 // [Relocation]
40 // - relocation information
41 // - constant part (doubles, longs and floats used in nmethod)
42 // - oop table
43 // [Code]
44 // - code body
45 // - exception handler
46 // - stub code
47 // [Debugging information]
48 // - oop array
49 // - data array
50 // - pcs
51 // [Exception handler table]
52 // - handler entry point array
53 // [Implicit Null Pointer exception table]
54 // - implicit null table array
55 // [Speculations]
56 // - encoded speculations array
57 // [JVMCINMethodData]
58 // - meta data for JVMCI compiled nmethod
59
60 #if INCLUDE_JVMCI
61 class FailedSpeculation;
62 class JVMCINMethodData;
63 #endif
64
65 class nmethod : public CompiledMethod {
66 friend class VMStructs;
67 friend class JVMCIVMStructs;
68 friend class NMethodSweeper;
69 friend class CodeCache; // scavengable oops
70 friend class JVMCINMethodData;
71
72 private:
73 // Shared fields for all nmethod's
74 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
75
76 // To support simple linked-list chaining of nmethods:
77 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
78
79 // STW two-phase nmethod root processing helpers.
80 //
81 // When determining liveness of a given nmethod to do code cache unloading,
82 // some collectors need to do different things depending on whether the nmethods
83 // need to absolutely be kept alive during root processing; "strong"ly reachable
84 // nmethods are known to be kept alive at root processing, but the liveness of
85 // "weak"ly reachable ones is to be determined later.
86 //
87 // We want to allow strong and weak processing of nmethods by different threads
88 // at the same time without heavy synchronization. Additional constraints are
89 // to make sure that every nmethod is processed a minimal amount of time, and
90 // nmethods themselves are always iterated at most once at a particular time.
91 //
92 // Note that strong processing work must be a superset of weak processing work
93 // for this code to work.
94 //
95 // We store state and claim information in the _oops_do_mark_link member, using
96 // the two LSBs for the state and the remaining upper bits for linking together
97 // nmethods that were already visited.
98 // The last element is self-looped, i.e. points to itself to avoid some special
99 // "end-of-list" sentinel value.
100 //
101 // _oops_do_mark_link special values:
102 //
103 // _oops_do_mark_link == NULL: the nmethod has not been visited at all yet, i.e.
104 // is Unclaimed.
105 //
106 // For other values, its lowest two bits indicate the following states of the nmethod:
107 //
108 // weak_request (WR): the nmethod has been claimed by a thread for weak processing
109 // weak_done (WD): weak processing has been completed for this nmethod.
110 // strong_request (SR): the nmethod has been found to need strong processing while
111 // being weak processed.
112 // strong_done (SD): strong processing has been completed for this nmethod .
113 //
114 // The following shows the _only_ possible progressions of the _oops_do_mark_link
115 // pointer.
116 //
117 // Given
118 // N as the nmethod
119 // X the current next value of _oops_do_mark_link
120 //
121 // Unclaimed (C)-> N|WR (C)-> X|WD: the nmethod has been processed weakly by
122 // a single thread.
123 // Unclaimed (C)-> N|WR (C)-> X|WD (O)-> X|SD: after weak processing has been
124 // completed (as above) another thread found that the nmethod needs strong
125 // processing after all.
126 // Unclaimed (C)-> N|WR (O)-> N|SR (C)-> X|SD: during weak processing another
127 // thread finds that the nmethod needs strong processing, marks it as such and
128 // terminates. The original thread completes strong processing.
129 // Unclaimed (C)-> N|SD (C)-> X|SD: the nmethod has been processed strongly from
130 // the beginning by a single thread.
131 //
132 // "|" describes the concatenation of bits in _oops_do_mark_link.
133 //
134 // The diagram also describes the threads responsible for changing the nmethod to
135 // the next state by marking the _transition_ with (C) and (O), which mean "current"
136 // and "other" thread respectively.
137 //
138 struct oops_do_mark_link; // Opaque data type.
139
140 // States used for claiming nmethods during root processing.
141 static const uint claim_weak_request_tag = 0;
142 static const uint claim_weak_done_tag = 1;
143 static const uint claim_strong_request_tag = 2;
144 static const uint claim_strong_done_tag = 3;
145
146 static oops_do_mark_link* mark_link(nmethod* nm, uint tag) {
147 assert(tag <= claim_strong_done_tag, "invalid tag %u", tag);
148 assert(is_aligned(nm, 4), "nmethod pointer must have zero lower two LSB");
149 return (oops_do_mark_link*)(((uintptr_t)nm & ~0x3) | tag);
150 }
151
152 static uint extract_state(oops_do_mark_link* link) {
153 return (uint)((uintptr_t)link & 0x3);
154 }
155
156 static nmethod* extract_nmethod(oops_do_mark_link* link) {
157 return (nmethod*)((uintptr_t)link & ~0x3);
158 }
159
160 void oops_do_log_change(const char* state);
161
162 static bool oops_do_has_weak_request(oops_do_mark_link* next) {
163 return extract_state(next) == claim_weak_request_tag;
164 }
165
166 static bool oops_do_has_any_strong_state(oops_do_mark_link* next) {
167 return extract_state(next) >= claim_strong_request_tag;
168 }
169
170 // Attempt Unclaimed -> N|WR transition. Returns true if successful.
171 bool oops_do_try_claim_weak_request();
172
173 // Attempt Unclaimed -> N|SD transition. Returns the current link.
174 oops_do_mark_link* oops_do_try_claim_strong_done();
175 // Attempt N|WR -> X|WD transition. Returns NULL if successful, X otherwise.
176 nmethod* oops_do_try_add_to_list_as_weak_done();
177
178 // Attempt X|WD -> N|SR transition. Returns the current link.
179 oops_do_mark_link* oops_do_try_add_strong_request(oops_do_mark_link* next);
180 // Attempt X|WD -> X|SD transition. Returns true if successful.
181 bool oops_do_try_claim_weak_done_as_strong_done(oops_do_mark_link* next);
182
183 // Do the N|SD -> X|SD transition.
184 void oops_do_add_to_list_as_strong_done();
185
186 // Sets this nmethod as strongly claimed (as part of N|SD -> X|SD and N|SR -> X|SD
187 // transitions).
188 void oops_do_set_strong_done(nmethod* old_head);
189
190 static nmethod* volatile _oops_do_mark_nmethods;
191 oops_do_mark_link* volatile _oops_do_mark_link;
192
193 // offsets for entry points
194 address _entry_point; // entry point with class check
195 address _verified_entry_point; // entry point without class check
196 address _osr_entry_point; // entry point for on stack replacement
197
198 // Offsets for different nmethod parts
199 int _exception_offset;
200 // Offset of the unwind handler if it exists
201 int _unwind_handler_offset;
202
203 int _consts_offset;
204 int _stub_offset;
205 int _oops_offset; // offset to where embedded oop table begins (inside data)
206 int _metadata_offset; // embedded meta data table
207 int _scopes_data_offset;
208 int _scopes_pcs_offset;
209 int _dependencies_offset;
210 int _handler_table_offset;
211 int _nul_chk_table_offset;
212 #if INCLUDE_JVMCI
213 int _speculations_offset;
214 int _jvmci_data_offset;
215 #endif
216 int _nmethod_end_offset;
217
218 int code_offset() const { return (address) code_begin() - header_begin(); }
219
220 // location in frame (offset for sp) that deopt can store the original
221 // pc during a deopt.
222 int _orig_pc_offset;
223
224 int _compile_id; // which compilation made this nmethod
225 int _comp_level; // compilation level
226
227 // protected by CodeCache_lock
228 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
229
230 // used by jvmti to track if an event has been posted for this nmethod.
231 bool _unload_reported;
232 bool _load_reported;
233
234 // Protected by CompiledMethod_lock
235 volatile signed char _state; // {not_installed, in_use, not_entrant, zombie, unloaded}
236
237 #ifdef ASSERT
238 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
239 #endif
240
241 #if INCLUDE_RTM_OPT
242 // RTM state at compile time. Used during deoptimization to decide
243 // whether to restart collecting RTM locking abort statistic again.
244 RTMState _rtm_state;
245 #endif
246
247 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed
248 // and is not made into a zombie. However, once the nmethod is made into
249 // a zombie, it will be locked one final time if CompiledMethodUnload
250 // event processing needs to be done.
251 volatile jint _lock_count;
252
253 // not_entrant method removal. Each mark_sweep pass will update
254 // this mark to current sweep invocation count if it is seen on the
255 // stack. An not_entrant method can be removed when there are no
256 // more activations, i.e., when the _stack_traversal_mark is less than
257 // current sweep traversal index.
258 volatile int64_t _stack_traversal_mark;
259
260 // The _hotness_counter indicates the hotness of a method. The higher
261 // the value the hotter the method. The hotness counter of a nmethod is
262 // set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
263 // is active while stack scanning (do_stack_scanning()). The hotness
264 // counter is decreased (by 1) while sweeping.
265 int _hotness_counter;
266
267 // Local state used to keep track of whether unloading is happening or not
268 volatile uint8_t _is_unloading_state;
269
270 // These are used for compiled synchronized native methods to
271 // locate the owner and stack slot for the BasicLock. They are
272 // needed because there is no debug information for compiled native
273 // wrappers and the oop maps are insufficient to allow
274 // frame::retrieve_receiver() to work. Currently they are expected
275 // to be byte offsets from the Java stack pointer for maximum code
276 // sharing between platforms. JVMTI's GetLocalInstance() uses these
277 // offsets to find the receiver for non-static native wrapper frames.
278 ByteSize _native_receiver_sp_offset;
279 ByteSize _native_basic_lock_sp_offset;
280
281 friend class nmethodLocker;
282
283 // For native wrappers
284 nmethod(Method* method,
285 CompilerType type,
286 int nmethod_size,
287 int compile_id,
288 CodeOffsets* offsets,
289 CodeBuffer *code_buffer,
290 int frame_size,
291 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
292 ByteSize basic_lock_sp_offset, /* synchronized natives only */
293 OopMapSet* oop_maps);
294
295 // Creation support
296 nmethod(Method* method,
297 CompilerType type,
298 int nmethod_size,
299 int compile_id,
300 int entry_bci,
301 CodeOffsets* offsets,
302 int orig_pc_offset,
303 DebugInformationRecorder *recorder,
304 Dependencies* dependencies,
305 CodeBuffer *code_buffer,
306 int frame_size,
307 OopMapSet* oop_maps,
308 ExceptionHandlerTable* handler_table,
309 ImplicitExceptionTable* nul_chk_table,
310 AbstractCompiler* compiler,
311 int comp_level
312 #if INCLUDE_JVMCI
313 , char* speculations,
314 int speculations_len,
315 int jvmci_data_size
316 #endif
317 );
318
319 // helper methods
320 void* operator new(size_t size, int nmethod_size, int comp_level) throw();
321
322 const char* reloc_string_for(u_char* begin, u_char* end);
323
324 bool try_transition(int new_state);
325
326 // Returns true if this thread changed the state of the nmethod or
327 // false if another thread performed the transition.
328 bool make_not_entrant_or_zombie(int state);
329 bool make_entrant() { Unimplemented(); return false; }
330 void inc_decompile_count();
331
332 // Inform external interfaces that a compiled method has been unloaded
333 void post_compiled_method_unload();
334
335 // Initialize fields to their default values
336 void init_defaults();
337
338 // Offsets
339 int content_offset() const { return content_begin() - header_begin(); }
340 int data_offset() const { return _data_offset; }
341
342 address header_end() const { return (address) header_begin() + header_size(); }
343
344 public:
345 // create nmethod with entry_bci
346 static nmethod* new_nmethod(const methodHandle& method,
347 int compile_id,
348 int entry_bci,
349 CodeOffsets* offsets,
350 int orig_pc_offset,
351 DebugInformationRecorder* recorder,
352 Dependencies* dependencies,
353 CodeBuffer *code_buffer,
354 int frame_size,
355 OopMapSet* oop_maps,
356 ExceptionHandlerTable* handler_table,
357 ImplicitExceptionTable* nul_chk_table,
358 AbstractCompiler* compiler,
359 int comp_level
360 #if INCLUDE_JVMCI
361 , char* speculations = NULL,
362 int speculations_len = 0,
363 int nmethod_mirror_index = -1,
364 const char* nmethod_mirror_name = NULL,
365 FailedSpeculation** failed_speculations = NULL
366 #endif
367 );
368
369 // Only used for unit tests.
370 nmethod()
371 : CompiledMethod(),
372 _is_unloading_state(0),
373 _native_receiver_sp_offset(in_ByteSize(-1)),
374 _native_basic_lock_sp_offset(in_ByteSize(-1)) {}
375
376
377 static nmethod* new_native_nmethod(const methodHandle& method,
378 int compile_id,
379 CodeBuffer *code_buffer,
380 int vep_offset,
381 int frame_complete,
382 int frame_size,
383 ByteSize receiver_sp_offset,
384 ByteSize basic_lock_sp_offset,
385 OopMapSet* oop_maps);
386
387 // type info
388 bool is_nmethod() const { return true; }
389 bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
390
391 // boundaries for different parts
392 address consts_begin () const { return header_begin() + _consts_offset ; }
393 address consts_end () const { return code_begin() ; }
394 address stub_begin () const { return header_begin() + _stub_offset ; }
395 address stub_end () const { return header_begin() + _oops_offset ; }
396 address exception_begin () const { return header_begin() + _exception_offset ; }
397 address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; }
398 oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; }
399 oop* oops_end () const { return (oop*) (header_begin() + _metadata_offset) ; }
400
401 Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
402 Metadata** metadata_end () const { return (Metadata**) _scopes_data_begin; }
403
404 address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
405 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
406 PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; }
407 address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
408 address dependencies_end () const { return header_begin() + _handler_table_offset ; }
409 address handler_table_begin () const { return header_begin() + _handler_table_offset ; }
410 address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
411 address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; }
412 #if INCLUDE_JVMCI
413 address nul_chk_table_end () const { return header_begin() + _speculations_offset ; }
414 address speculations_begin () const { return header_begin() + _speculations_offset ; }
415 address speculations_end () const { return header_begin() + _jvmci_data_offset ; }
416 address jvmci_data_begin () const { return header_begin() + _jvmci_data_offset ; }
417 address jvmci_data_end () const { return header_begin() + _nmethod_end_offset ; }
418 #else
419 address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
420 #endif
421
422 // Sizes
423 int oops_size () const { return (address) oops_end () - (address) oops_begin (); }
424 int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); }
425 int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
426 #if INCLUDE_JVMCI
427 int speculations_size () const { return speculations_end () - speculations_begin (); }
428 int jvmci_data_size () const { return jvmci_data_end () - jvmci_data_begin (); }
429 #endif
430
431 int oops_count() const { assert(oops_size() % oopSize == 0, ""); return (oops_size() / oopSize) + 1; }
432 int metadata_count() const { assert(metadata_size() % wordSize == 0, ""); return (metadata_size() / wordSize) + 1; }
433
434 int total_size () const;
435
436 void dec_hotness_counter() { _hotness_counter--; }
437 void set_hotness_counter(int val) { _hotness_counter = val; }
438 int hotness_counter() const { return _hotness_counter; }
439
440 // Containment
441 bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
442 bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); }
443 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
444 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
445
446 // entry points
447 address entry_point() const { return _entry_point; } // normal entry point
448 address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
449
450 // flag accessing and manipulation
451 bool is_not_installed() const { return _state == not_installed; }
452 bool is_in_use() const { return _state <= in_use; }
453 bool is_alive() const { return _state < unloaded; }
454 bool is_not_entrant() const { return _state == not_entrant; }
455 bool is_zombie() const { return _state == zombie; }
456 bool is_unloaded() const { return _state == unloaded; }
457
458 void clear_unloading_state();
459 virtual bool is_unloading();
460 virtual void do_unloading(bool unloading_occurred);
461
462 #if INCLUDE_RTM_OPT
463 // rtm state accessing and manipulating
464 RTMState rtm_state() const { return _rtm_state; }
465 void set_rtm_state(RTMState state) { _rtm_state = state; }
466 #endif
467
468 bool make_in_use() {
469 return try_transition(in_use);
470 }
471 // Make the nmethod non entrant. The nmethod will continue to be
472 // alive. It is used when an uncommon trap happens. Returns true
473 // if this thread changed the state of the nmethod or false if
474 // another thread performed the transition.
475 bool make_not_entrant() {
476 assert(!method()->is_method_handle_intrinsic(), "Cannot make MH intrinsic not entrant");
477 return make_not_entrant_or_zombie(not_entrant);
478 }
479 bool make_not_used() { return make_not_entrant(); }
480 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
481
482 int get_state() const {
483 return _state;
484 }
485
486 void make_unloaded();
487
488 bool has_dependencies() { return dependencies_size() != 0; }
489 void print_dependencies() PRODUCT_RETURN;
490 void flush_dependencies(bool delete_immediately);
491 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
492 void set_has_flushed_dependencies() {
493 assert(!has_flushed_dependencies(), "should only happen once");
494 _has_flushed_dependencies = 1;
495 }
496
497 int comp_level() const { return _comp_level; }
498
499 void unlink_from_method();
500
501 // Support for oops in scopes and relocs:
502 // Note: index 0 is reserved for null.
503 oop oop_at(int index) const;
504 oop oop_at_phantom(int index) const; // phantom reference
505 oop* oop_addr_at(int index) const { // for GC
506 // relocation indexes are biased by 1 (because 0 is reserved)
507 assert(index > 0 && index <= oops_count(), "must be a valid non-zero index");
508 assert(!_oops_are_stale, "oops are stale");
509 return &oops_begin()[index - 1];
510 }
511
512 // Support for meta data in scopes and relocs:
513 // Note: index 0 is reserved for null.
514 Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
515 Metadata** metadata_addr_at(int index) const { // for GC
516 // relocation indexes are biased by 1 (because 0 is reserved)
517 assert(index > 0 && index <= metadata_count(), "must be a valid non-zero index");
518 return &metadata_begin()[index - 1];
519 }
520
521 void copy_values(GrowableArray<jobject>* oops);
522 void copy_values(GrowableArray<Metadata*>* metadata);
523
524 // Relocation support
525 private:
526 void fix_oop_relocations(address begin, address end, bool initialize_immediates);
527 inline void initialize_immediate_oop(oop* dest, jobject handle);
528
529 public:
530 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
531 void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); }
532
533 // Sweeper support
534 int64_t stack_traversal_mark() { return _stack_traversal_mark; }
535 void set_stack_traversal_mark(int64_t l) { _stack_traversal_mark = l; }
536
537 // On-stack replacement support
538 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
539 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
540 void invalidate_osr_method();
541 nmethod* osr_link() const { return _osr_link; }
542 void set_osr_link(nmethod *n) { _osr_link = n; }
543
544 // Verify calls to dead methods have been cleaned.
545 void verify_clean_inline_caches();
546
547 // unlink and deallocate this nmethod
548 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
549 // expected to use any other private methods/data in this class.
550
551 protected:
552 void flush();
553
554 public:
555 // When true is returned, it is unsafe to remove this nmethod even if
556 // it is a zombie, since the VM or the ServiceThread might still be
557 // using it.
558 bool is_locked_by_vm() const { return _lock_count >0; }
559
560 // See comment at definition of _last_seen_on_stack
561 void mark_as_seen_on_stack();
562 bool can_convert_to_zombie();
563
564 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
565 void set_method(Method* method) { _method = method; }
566
567 #if INCLUDE_JVMCI
568 // Gets the JVMCI name of this nmethod.
569 const char* jvmci_name();
570
571 // Records the pending failed speculation in the
572 // JVMCI speculation log associated with this nmethod.
573 void update_speculation(JavaThread* thread);
574
575 // Gets the data specific to a JVMCI compiled method.
576 // This returns a non-NULL value iff this nmethod was
577 // compiled by the JVMCI compiler.
578 JVMCINMethodData* jvmci_nmethod_data() const {
579 return jvmci_data_size() == 0 ? NULL : (JVMCINMethodData*) jvmci_data_begin();
580 }
581 #endif
582
583 public:
584 void oops_do(OopClosure* f) { oops_do(f, false); }
585 void oops_do(OopClosure* f, bool allow_dead);
586
587 // All-in-one claiming of nmethods: returns true if the caller successfully claimed that
588 // nmethod.
589 bool oops_do_try_claim();
590
591 // Class containing callbacks for the oops_do_process_weak/strong() methods
592 // below.
593 class OopsDoProcessor {
594 public:
595 // Process the oops of the given nmethod based on whether it has been called
596 // in a weak or strong processing context, i.e. apply either weak or strong
597 // work on it.
598 virtual void do_regular_processing(nmethod* nm) = 0;
599 // Assuming that the oops of the given nmethod has already been its weak
600 // processing applied, apply the remaining strong processing part.
601 virtual void do_remaining_strong_processing(nmethod* nm) = 0;
602 };
603
604 // The following two methods do the work corresponding to weak/strong nmethod
605 // processing.
606 void oops_do_process_weak(OopsDoProcessor* p);
607 void oops_do_process_strong(OopsDoProcessor* p);
608
609 static void oops_do_marking_prologue();
610 static void oops_do_marking_epilogue();
611
612 private:
613 ScopeDesc* scope_desc_in(address begin, address end);
614
615 address* orig_pc_addr(const frame* fr);
616
617 // used by jvmti to track if the load and unload events has been reported
618 bool unload_reported() const { return _unload_reported; }
619 void set_unload_reported() { _unload_reported = true; }
620 bool load_reported() const { return _load_reported; }
621 void set_load_reported() { _load_reported = true; }
622
623 public:
624 // copying of debugging information
625 void copy_scopes_pcs(PcDesc* pcs, int count);
626 void copy_scopes_data(address buffer, int size);
627
628 // Accessor/mutator for the original pc of a frame before a frame was deopted.
629 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
630 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
631
632 // jvmti support:
633 void post_compiled_method_load_event(JvmtiThreadState* state = NULL);
634
635 // verify operations
636 void verify();
637 void verify_scopes();
638 void verify_interrupt_point(address interrupt_point);
639
640 // Disassemble this nmethod with additional debug information, e.g. information about blocks.
641 void decode2(outputStream* st) const;
642 void print_constant_pool(outputStream* st);
643
644 // Avoid hiding of parent's 'decode(outputStream*)' method.
645 void decode(outputStream* st) const { decode2(st); } // just delegate here.
646
647 // printing support
648 void print() const;
649 void print(outputStream* st) const;
650 void print_code();
651
652 #if defined(SUPPORT_DATA_STRUCTS)
653 // print output in opt build for disassembler library
654 void print_relocations() PRODUCT_RETURN;
655 void print_pcs() { print_pcs_on(tty); }
656 void print_pcs_on(outputStream* st);
657 void print_scopes() { print_scopes_on(tty); }
658 void print_scopes_on(outputStream* st) PRODUCT_RETURN;
659 void print_value_on(outputStream* st) const;
660 void print_handler_table();
661 void print_nul_chk_table();
662 void print_recorded_oop(int log_n, int index);
663 void print_recorded_oops();
664 void print_recorded_metadata();
665
666 void print_oops(outputStream* st); // oops from the underlying CodeBlob.
667 void print_metadata(outputStream* st); // metadata in metadata pool.
668 #else
669 // void print_pcs() PRODUCT_RETURN;
670 void print_pcs() { return; }
671 #endif
672
673 void print_calls(outputStream* st) PRODUCT_RETURN;
674 static void print_statistics() PRODUCT_RETURN;
675
676 void maybe_print_nmethod(DirectiveSet* directive);
677 void print_nmethod(bool print_code);
678
679 // need to re-define this from CodeBlob else the overload hides it
680 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
681 void print_on(outputStream* st, const char* msg) const;
682
683 // Logging
684 void log_identity(xmlStream* log) const;
685 void log_new_nmethod() const;
686 void log_state_change() const;
687
688 // Prints block-level comments, including nmethod specific block labels:
689 virtual void print_block_comment(outputStream* stream, address block_begin) const {
690 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
691 print_nmethod_labels(stream, block_begin);
692 CodeBlob::print_block_comment(stream, block_begin);
693 #endif
694 }
695
696 void print_nmethod_labels(outputStream* stream, address block_begin, bool print_section_labels=true) const;
697 const char* nmethod_section_label(address pos) const;
698
699 // returns whether this nmethod has code comments.
700 bool has_code_comment(address begin, address end);
701 // Prints a comment for one native instruction (reloc info, pc desc)
702 void print_code_comment_on(outputStream* st, int column, address begin, address end);
703
704 // Compiler task identification. Note that all OSR methods
705 // are numbered in an independent sequence if CICountOSR is true,
706 // and native method wrappers are also numbered independently if
707 // CICountNative is true.
708 virtual int compile_id() const { return _compile_id; }
709 const char* compile_kind() const;
710
711 // tells if any of this method's dependencies have been invalidated
712 // (this is expensive!)
713 static void check_all_dependencies(DepChange& changes);
714
715 // tells if this compiled method is dependent on the given changes,
716 // and the changes have invalidated it
717 bool check_dependency_on(DepChange& changes);
718
719 // Fast breakpoint support. Tells if this compiled method is
720 // dependent on the given method. Returns true if this nmethod
721 // corresponds to the given method as well.
722 virtual bool is_dependent_on_method(Method* dependee);
723
724 // is it ok to patch at address?
725 bool is_patchable_at(address instr_address);
726
727 // JVMTI's GetLocalInstance() support
728 ByteSize native_receiver_sp_offset() {
729 return _native_receiver_sp_offset;
730 }
731 ByteSize native_basic_lock_sp_offset() {
732 return _native_basic_lock_sp_offset;
733 }
734
735 // support for code generation
736 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
737 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
738 static int state_offset() { return offset_of(nmethod, _state); }
739
740 virtual void metadata_do(MetadataClosure* f);
741
742 NativeCallWrapper* call_wrapper_at(address call) const;
743 NativeCallWrapper* call_wrapper_before(address return_pc) const;
744 address call_instruction_address(address pc) const;
745
746 virtual CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) const;
747 virtual CompiledStaticCall* compiledStaticCall_at(address addr) const;
748 virtual CompiledStaticCall* compiledStaticCall_before(address addr) const;
749 };
750
751 // Locks an nmethod so its code will not get removed and it will not
752 // be made into a zombie, even if it is a not_entrant method. After the
753 // nmethod becomes a zombie, if CompiledMethodUnload event processing
754 // needs to be done, then lock_nmethod() is used directly to keep the
755 // generated code from being reused too early.
756 class nmethodLocker : public StackObj {
757 CompiledMethod* _nm;
758
759 public:
760
761 // note: nm can be NULL
762 // Only JvmtiDeferredEvent::compiled_method_unload_event()
763 // should pass zombie_ok == true.
764 static void lock_nmethod(CompiledMethod* nm, bool zombie_ok = false);
765 static void unlock_nmethod(CompiledMethod* nm); // (ditto)
766
767 nmethodLocker(address pc); // derive nm from pc
768 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
769 nmethodLocker(CompiledMethod *nm) {
770 _nm = nm;
771 lock(_nm);
772 }
773
774 static void lock(CompiledMethod* method, bool zombie_ok = false) {
775 if (method == NULL) return;
776 lock_nmethod(method, zombie_ok);
777 }
778
779 static void unlock(CompiledMethod* method) {
780 if (method == NULL) return;
781 unlock_nmethod(method);
782 }
783
784 nmethodLocker() { _nm = NULL; }
785 ~nmethodLocker() {
786 unlock(_nm);
787 }
788
789 CompiledMethod* code() { return _nm; }
790 void set_code(CompiledMethod* new_nm, bool zombie_ok = false) {
791 unlock(_nm); // note: This works even if _nm==new_nm.
792 _nm = new_nm;
793 lock(_nm, zombie_ok);
794 }
795 };
796
797 #endif // SHARE_CODE_NMETHOD_HPP