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 *
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,
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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 _native_invokers_offset;
211 int _handler_table_offset;
212 int _nul_chk_table_offset;
213 #if INCLUDE_JVMCI
214 int _speculations_offset;
215 int _jvmci_data_offset;
216 #endif
217 int _nmethod_end_offset;
218
219 int code_offset() const { return (address) code_begin() - header_begin(); }
220
221 // location in frame (offset for sp) that deopt can store the original
222 // pc during a deopt.
223 int _orig_pc_offset;
224
225 int _compile_id; // which compilation made this nmethod
226 int _comp_level; // compilation level
227
228 // protected by CodeCache_lock
229 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
230
231 // used by jvmti to track if an event has been posted for this nmethod.
232 bool _unload_reported;
233 bool _load_reported;
234
235 // Protected by CompiledMethod_lock
236 volatile signed char _state; // {not_installed, in_use, not_entrant, zombie, unloaded}
237
238 #ifdef ASSERT
239 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
240 #endif
241
242 #if INCLUDE_RTM_OPT
243 // RTM state at compile time. Used during deoptimization to decide
244 // whether to restart collecting RTM locking abort statistic again.
245 RTMState _rtm_state;
246 #endif
247
248 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed
249 // and is not made into a zombie. However, once the nmethod is made into
250 // a zombie, it will be locked one final time if CompiledMethodUnload
251 // event processing needs to be done.
252 volatile jint _lock_count;
253
254 // not_entrant method removal. Each mark_sweep pass will update
255 // this mark to current sweep invocation count if it is seen on the
256 // stack. An not_entrant method can be removed when there are no
257 // more activations, i.e., when the _stack_traversal_mark is less than
258 // current sweep traversal index.
259 volatile int64_t _stack_traversal_mark;
260
261 // The _hotness_counter indicates the hotness of a method. The higher
262 // the value the hotter the method. The hotness counter of a nmethod is
263 // set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
264 // is active while stack scanning (do_stack_scanning()). The hotness
265 // counter is decreased (by 1) while sweeping.
266 int _hotness_counter;
267
268 // Local state used to keep track of whether unloading is happening or not
269 volatile uint8_t _is_unloading_state;
270
271 // These are used for compiled synchronized native methods to
272 // locate the owner and stack slot for the BasicLock. They are
273 // needed because there is no debug information for compiled native
274 // wrappers and the oop maps are insufficient to allow
275 // frame::retrieve_receiver() to work. Currently they are expected
276 // to be byte offsets from the Java stack pointer for maximum code
277 // sharing between platforms. JVMTI's GetLocalInstance() uses these
278 // offsets to find the receiver for non-static native wrapper frames.
279 ByteSize _native_receiver_sp_offset;
280 ByteSize _native_basic_lock_sp_offset;
281
282 friend class nmethodLocker;
283
284 // For native wrappers
285 nmethod(Method* method,
286 CompilerType type,
287 int nmethod_size,
288 int compile_id,
289 CodeOffsets* offsets,
290 CodeBuffer *code_buffer,
291 int frame_size,
292 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
293 ByteSize basic_lock_sp_offset, /* synchronized natives only */
294 OopMapSet* oop_maps);
295
296 // Creation support
297 nmethod(Method* method,
298 CompilerType type,
299 int nmethod_size,
300 int compile_id,
301 int entry_bci,
302 CodeOffsets* offsets,
303 int orig_pc_offset,
304 DebugInformationRecorder *recorder,
305 Dependencies* dependencies,
306 CodeBuffer *code_buffer,
307 int frame_size,
308 OopMapSet* oop_maps,
309 ExceptionHandlerTable* handler_table,
310 ImplicitExceptionTable* nul_chk_table,
311 AbstractCompiler* compiler,
312 int comp_level,
313 const GrowableArrayView<RuntimeStub*>& native_invokers
314 #if INCLUDE_JVMCI
315 , char* speculations,
316 int speculations_len,
317 int jvmci_data_size
318 #endif
319 );
320
321 // helper methods
322 void* operator new(size_t size, int nmethod_size, int comp_level) throw();
323
324 const char* reloc_string_for(u_char* begin, u_char* end);
325
326 bool try_transition(int new_state);
327
328 // Returns true if this thread changed the state of the nmethod or
329 // false if another thread performed the transition.
330 bool make_not_entrant_or_zombie(int state);
331 bool make_entrant() { Unimplemented(); return false; }
332 void inc_decompile_count();
333
334 // Inform external interfaces that a compiled method has been unloaded
335 void post_compiled_method_unload();
336
337 // Initialize fields to their default values
338 void init_defaults();
339
340 // Offsets
341 int content_offset() const { return content_begin() - header_begin(); }
342 int data_offset() const { return _data_offset; }
343
344 address header_end() const { return (address) header_begin() + header_size(); }
345
346 public:
347 // create nmethod with entry_bci
348 static nmethod* new_nmethod(const methodHandle& method,
349 int compile_id,
350 int entry_bci,
351 CodeOffsets* offsets,
352 int orig_pc_offset,
353 DebugInformationRecorder* recorder,
354 Dependencies* dependencies,
355 CodeBuffer *code_buffer,
356 int frame_size,
357 OopMapSet* oop_maps,
358 ExceptionHandlerTable* handler_table,
359 ImplicitExceptionTable* nul_chk_table,
360 AbstractCompiler* compiler,
361 int comp_level,
362 const GrowableArrayView<RuntimeStub*>& native_invokers = GrowableArrayView<RuntimeStub*>::EMPTY
363 #if INCLUDE_JVMCI
364 , char* speculations = NULL,
365 int speculations_len = 0,
366 int nmethod_mirror_index = -1,
367 const char* nmethod_mirror_name = NULL,
368 FailedSpeculation** failed_speculations = NULL
369 #endif
370 );
371
372 // Only used for unit tests.
373 nmethod()
374 : CompiledMethod(),
375 _is_unloading_state(0),
376 _native_receiver_sp_offset(in_ByteSize(-1)),
377 _native_basic_lock_sp_offset(in_ByteSize(-1)) {}
378
379
380 static nmethod* new_native_nmethod(const methodHandle& method,
381 int compile_id,
382 CodeBuffer *code_buffer,
383 int vep_offset,
384 int frame_complete,
385 int frame_size,
386 ByteSize receiver_sp_offset,
387 ByteSize basic_lock_sp_offset,
388 OopMapSet* oop_maps);
389
390 // type info
391 bool is_nmethod() const { return true; }
392 bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
393
394 // boundaries for different parts
395 address consts_begin () const { return header_begin() + _consts_offset ; }
396 address consts_end () const { return code_begin() ; }
397 address stub_begin () const { return header_begin() + _stub_offset ; }
398 address stub_end () const { return header_begin() + _oops_offset ; }
399 address exception_begin () const { return header_begin() + _exception_offset ; }
400 address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; }
401 oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; }
402 oop* oops_end () const { return (oop*) (header_begin() + _metadata_offset) ; }
403
404 Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
405 Metadata** metadata_end () const { return (Metadata**) _scopes_data_begin; }
406
407 address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
408 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
409 PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; }
410 address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
411 address dependencies_end () const { return header_begin() + _native_invokers_offset ; }
412 RuntimeStub** native_invokers_begin() const { return (RuntimeStub**)(header_begin() + _native_invokers_offset) ; }
413 RuntimeStub** native_invokers_end () const { return (RuntimeStub**)(header_begin() + _handler_table_offset); }
414 address handler_table_begin () const { return header_begin() + _handler_table_offset ; }
415 address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
416 address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; }
417 #if INCLUDE_JVMCI
418 address nul_chk_table_end () const { return header_begin() + _speculations_offset ; }
419 address speculations_begin () const { return header_begin() + _speculations_offset ; }
420 address speculations_end () const { return header_begin() + _jvmci_data_offset ; }
421 address jvmci_data_begin () const { return header_begin() + _jvmci_data_offset ; }
422 address jvmci_data_end () const { return header_begin() + _nmethod_end_offset ; }
423 #else
424 address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
425 #endif
426
427 // Sizes
428 int oops_size () const { return (address) oops_end () - (address) oops_begin (); }
429 int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); }
430 int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
431 #if INCLUDE_JVMCI
432 int speculations_size () const { return speculations_end () - speculations_begin (); }
433 int jvmci_data_size () const { return jvmci_data_end () - jvmci_data_begin (); }
434 #endif
435
436 int oops_count() const { assert(oops_size() % oopSize == 0, ""); return (oops_size() / oopSize) + 1; }
437 int metadata_count() const { assert(metadata_size() % wordSize == 0, ""); return (metadata_size() / wordSize) + 1; }
438
439 int total_size () const;
440
441 void dec_hotness_counter() { _hotness_counter--; }
442 void set_hotness_counter(int val) { _hotness_counter = val; }
443 int hotness_counter() const { return _hotness_counter; }
444
445 // Containment
446 bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
447 bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); }
448 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
449 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
450
451 // entry points
452 address entry_point() const { return _entry_point; } // normal entry point
453 address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
454
455 // flag accessing and manipulation
456 bool is_not_installed() const { return _state == not_installed; }
457 bool is_in_use() const { return _state <= in_use; }
458 bool is_alive() const { return _state < unloaded; }
459 bool is_not_entrant() const { return _state == not_entrant; }
460 bool is_zombie() const { return _state == zombie; }
461 bool is_unloaded() const { return _state == unloaded; }
462
463 void clear_unloading_state();
464 virtual bool is_unloading();
465 virtual void do_unloading(bool unloading_occurred);
466
467 #if INCLUDE_RTM_OPT
468 // rtm state accessing and manipulating
469 RTMState rtm_state() const { return _rtm_state; }
470 void set_rtm_state(RTMState state) { _rtm_state = state; }
471 #endif
472
473 bool make_in_use() {
474 return try_transition(in_use);
475 }
476 // Make the nmethod non entrant. The nmethod will continue to be
477 // alive. It is used when an uncommon trap happens. Returns true
478 // if this thread changed the state of the nmethod or false if
479 // another thread performed the transition.
480 bool make_not_entrant() {
481 assert(!method()->is_method_handle_intrinsic(), "Cannot make MH intrinsic not entrant");
482 return make_not_entrant_or_zombie(not_entrant);
483 }
484 bool make_not_used() { return make_not_entrant(); }
485 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
486
487 int get_state() const {
488 return _state;
489 }
490
491 void make_unloaded();
492
493 bool has_dependencies() { return dependencies_size() != 0; }
494 void print_dependencies() PRODUCT_RETURN;
495 void flush_dependencies(bool delete_immediately);
496 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
497 void set_has_flushed_dependencies() {
498 assert(!has_flushed_dependencies(), "should only happen once");
499 _has_flushed_dependencies = 1;
500 }
501
502 int comp_level() const { return _comp_level; }
503
504 void unlink_from_method();
505
506 // Support for oops in scopes and relocs:
507 // Note: index 0 is reserved for null.
508 oop oop_at(int index) const;
509 oop oop_at_phantom(int index) const; // phantom reference
510 oop* oop_addr_at(int index) const { // for GC
511 // relocation indexes are biased by 1 (because 0 is reserved)
512 assert(index > 0 && index <= oops_count(), "must be a valid non-zero index");
513 assert(!_oops_are_stale, "oops are stale");
514 return &oops_begin()[index - 1];
515 }
516
517 // Support for meta data in scopes and relocs:
518 // Note: index 0 is reserved for null.
519 Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
520 Metadata** metadata_addr_at(int index) const { // for GC
521 // relocation indexes are biased by 1 (because 0 is reserved)
522 assert(index > 0 && index <= metadata_count(), "must be a valid non-zero index");
523 return &metadata_begin()[index - 1];
524 }
525
526 void copy_values(GrowableArray<jobject>* oops);
527 void copy_values(GrowableArray<Metadata*>* metadata);
528
529 void free_native_invokers();
530
531 // Relocation support
532 private:
533 void fix_oop_relocations(address begin, address end, bool initialize_immediates);
534 inline void initialize_immediate_oop(oop* dest, jobject handle);
535
536 public:
537 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
538 void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); }
539
540 // Sweeper support
541 int64_t stack_traversal_mark() { return _stack_traversal_mark; }
542 void set_stack_traversal_mark(int64_t l) { _stack_traversal_mark = l; }
543
544 // On-stack replacement support
545 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
546 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
547 void invalidate_osr_method();
548 nmethod* osr_link() const { return _osr_link; }
549 void set_osr_link(nmethod *n) { _osr_link = n; }
550
551 // Verify calls to dead methods have been cleaned.
552 void verify_clean_inline_caches();
553
554 // unlink and deallocate this nmethod
555 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
556 // expected to use any other private methods/data in this class.
557
558 protected:
559 void flush();
560
561 public:
562 // When true is returned, it is unsafe to remove this nmethod even if
563 // it is a zombie, since the VM or the ServiceThread might still be
564 // using it.
565 bool is_locked_by_vm() const { return _lock_count >0; }
566
567 // See comment at definition of _last_seen_on_stack
568 void mark_as_seen_on_stack();
569 bool can_convert_to_zombie();
570
571 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
572 void set_method(Method* method) { _method = method; }
573
574 #if INCLUDE_JVMCI
575 // Gets the JVMCI name of this nmethod.
576 const char* jvmci_name();
577
578 // Records the pending failed speculation in the
579 // JVMCI speculation log associated with this nmethod.
580 void update_speculation(JavaThread* thread);
581
582 // Gets the data specific to a JVMCI compiled method.
583 // This returns a non-NULL value iff this nmethod was
584 // compiled by the JVMCI compiler.
585 JVMCINMethodData* jvmci_nmethod_data() const {
586 return jvmci_data_size() == 0 ? NULL : (JVMCINMethodData*) jvmci_data_begin();
587 }
588 #endif
589
590 public:
591 void oops_do(OopClosure* f) { oops_do(f, false); }
592 void oops_do(OopClosure* f, bool allow_dead);
593
594 // All-in-one claiming of nmethods: returns true if the caller successfully claimed that
595 // nmethod.
596 bool oops_do_try_claim();
597
598 // Class containing callbacks for the oops_do_process_weak/strong() methods
599 // below.
600 class OopsDoProcessor {
601 public:
602 // Process the oops of the given nmethod based on whether it has been called
603 // in a weak or strong processing context, i.e. apply either weak or strong
604 // work on it.
605 virtual void do_regular_processing(nmethod* nm) = 0;
606 // Assuming that the oops of the given nmethod has already been its weak
607 // processing applied, apply the remaining strong processing part.
608 virtual void do_remaining_strong_processing(nmethod* nm) = 0;
609 };
610
611 // The following two methods do the work corresponding to weak/strong nmethod
612 // processing.
613 void oops_do_process_weak(OopsDoProcessor* p);
614 void oops_do_process_strong(OopsDoProcessor* p);
615
616 static void oops_do_marking_prologue();
617 static void oops_do_marking_epilogue();
618
619 private:
620 ScopeDesc* scope_desc_in(address begin, address end);
621
622 address* orig_pc_addr(const frame* fr);
623
624 // used by jvmti to track if the load and unload events has been reported
625 bool unload_reported() const { return _unload_reported; }
626 void set_unload_reported() { _unload_reported = true; }
627 bool load_reported() const { return _load_reported; }
628 void set_load_reported() { _load_reported = true; }
629
630 public:
631 // copying of debugging information
632 void copy_scopes_pcs(PcDesc* pcs, int count);
633 void copy_scopes_data(address buffer, int size);
634
635 // Accessor/mutator for the original pc of a frame before a frame was deopted.
636 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
637 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
638
639 // jvmti support:
640 void post_compiled_method_load_event(JvmtiThreadState* state = NULL);
641
642 // verify operations
643 void verify();
644 void verify_scopes();
645 void verify_interrupt_point(address interrupt_point);
646
647 // Disassemble this nmethod with additional debug information, e.g. information about blocks.
648 void decode2(outputStream* st) const;
649 void print_constant_pool(outputStream* st);
650
651 // Avoid hiding of parent's 'decode(outputStream*)' method.
652 void decode(outputStream* st) const { decode2(st); } // just delegate here.
653
654 // printing support
655 void print() const;
656 void print(outputStream* st) const;
657 void print_code();
658
659 #if defined(SUPPORT_DATA_STRUCTS)
660 // print output in opt build for disassembler library
661 void print_relocations() PRODUCT_RETURN;
662 void print_pcs() { print_pcs_on(tty); }
663 void print_pcs_on(outputStream* st);
664 void print_scopes() { print_scopes_on(tty); }
665 void print_scopes_on(outputStream* st) PRODUCT_RETURN;
666 void print_value_on(outputStream* st) const;
667 void print_native_invokers();
668 void print_handler_table();
669 void print_nul_chk_table();
670 void print_recorded_oop(int log_n, int index);
671 void print_recorded_oops();
672 void print_recorded_metadata();
673
674 void print_oops(outputStream* st); // oops from the underlying CodeBlob.
675 void print_metadata(outputStream* st); // metadata in metadata pool.
676 #else
677 // void print_pcs() PRODUCT_RETURN;
678 void print_pcs() { return; }
679 #endif
680
681 void print_calls(outputStream* st) PRODUCT_RETURN;
682 static void print_statistics() PRODUCT_RETURN;
683
684 void maybe_print_nmethod(DirectiveSet* directive);
685 void print_nmethod(bool print_code);
686
687 // need to re-define this from CodeBlob else the overload hides it
688 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
689 void print_on(outputStream* st, const char* msg) const;
690
691 // Logging
692 void log_identity(xmlStream* log) const;
693 void log_new_nmethod() const;
694 void log_state_change() const;
695
696 // Prints block-level comments, including nmethod specific block labels:
697 virtual void print_block_comment(outputStream* stream, address block_begin) const {
698 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
699 print_nmethod_labels(stream, block_begin);
700 CodeBlob::print_block_comment(stream, block_begin);
701 #endif
702 }
703
704 void print_nmethod_labels(outputStream* stream, address block_begin, bool print_section_labels=true) const;
705 const char* nmethod_section_label(address pos) const;
706
707 // returns whether this nmethod has code comments.
708 bool has_code_comment(address begin, address end);
709 // Prints a comment for one native instruction (reloc info, pc desc)
710 void print_code_comment_on(outputStream* st, int column, address begin, address end);
711
712 // Compiler task identification. Note that all OSR methods
713 // are numbered in an independent sequence if CICountOSR is true,
714 // and native method wrappers are also numbered independently if
715 // CICountNative is true.
716 virtual int compile_id() const { return _compile_id; }
717 const char* compile_kind() const;
718
719 // tells if any of this method's dependencies have been invalidated
720 // (this is expensive!)
721 static void check_all_dependencies(DepChange& changes);
722
723 // tells if this compiled method is dependent on the given changes,
724 // and the changes have invalidated it
725 bool check_dependency_on(DepChange& changes);
726
727 // Fast breakpoint support. Tells if this compiled method is
728 // dependent on the given method. Returns true if this nmethod
729 // corresponds to the given method as well.
730 virtual bool is_dependent_on_method(Method* dependee);
731
732 // is it ok to patch at address?
733 bool is_patchable_at(address instr_address);
734
735 // JVMTI's GetLocalInstance() support
736 ByteSize native_receiver_sp_offset() {
737 return _native_receiver_sp_offset;
738 }
739 ByteSize native_basic_lock_sp_offset() {
740 return _native_basic_lock_sp_offset;
741 }
742
743 // support for code generation
744 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
745 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
746 static int state_offset() { return offset_of(nmethod, _state); }
747
748 virtual void metadata_do(MetadataClosure* f);
749
750 NativeCallWrapper* call_wrapper_at(address call) const;
751 NativeCallWrapper* call_wrapper_before(address return_pc) const;
752 address call_instruction_address(address pc) const;
753
754 virtual CompiledStaticCall* compiledStaticCall_at(Relocation* call_site) const;
755 virtual CompiledStaticCall* compiledStaticCall_at(address addr) const;
756 virtual CompiledStaticCall* compiledStaticCall_before(address addr) const;
757 };
758
759 // Locks an nmethod so its code will not get removed and it will not
760 // be made into a zombie, even if it is a not_entrant method. After the
761 // nmethod becomes a zombie, if CompiledMethodUnload event processing
762 // needs to be done, then lock_nmethod() is used directly to keep the
763 // generated code from being reused too early.
764 class nmethodLocker : public StackObj {
765 CompiledMethod* _nm;
766
767 public:
768
769 // note: nm can be NULL
770 // Only JvmtiDeferredEvent::compiled_method_unload_event()
771 // should pass zombie_ok == true.
772 static void lock_nmethod(CompiledMethod* nm, bool zombie_ok = false);
773 static void unlock_nmethod(CompiledMethod* nm); // (ditto)
774
775 nmethodLocker(address pc); // derive nm from pc
776 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
777 nmethodLocker(CompiledMethod *nm) {
778 _nm = nm;
779 lock(_nm);
780 }
781
782 static void lock(CompiledMethod* method, bool zombie_ok = false) {
783 if (method == NULL) return;
784 lock_nmethod(method, zombie_ok);
785 }
786
787 static void unlock(CompiledMethod* method) {
788 if (method == NULL) return;
789 unlock_nmethod(method);
790 }
791
792 nmethodLocker() { _nm = NULL; }
793 ~nmethodLocker() {
794 unlock(_nm);
795 }
796
797 CompiledMethod* code() { return _nm; }
798 void set_code(CompiledMethod* new_nm, bool zombie_ok = false) {
799 unlock(_nm); // note: This works even if _nm==new_nm.
800 _nm = new_nm;
801 lock(_nm, zombie_ok);
802 }
803 };
804
805 #endif // SHARE_CODE_NMETHOD_HPP