1 /*
2 * Copyright (c) 1997, 2026, 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.
22 *
23 */
24
25 #ifndef SHARE_CODE_NMETHOD_HPP
26 #define SHARE_CODE_NMETHOD_HPP
27
28 #include "code/codeBlob.hpp"
29 #include "code/pcDesc.hpp"
30 #include "compiler/compilerDefinitions.hpp"
31 #include "oops/metadata.hpp"
32 #include "oops/method.hpp"
33 #include "runtime/mutexLocker.hpp"
34
35 class AbstractCompiler;
36 class CompiledDirectCall;
37 class CompiledIC;
38 class CompiledICData;
39 class CompileTask;
40 class DepChange;
41 class Dependencies;
42 class DirectiveSet;
43 class DebugInformationRecorder;
44 class ExceptionHandlerTable;
45 class ImplicitExceptionTable;
46 class JvmtiThreadState;
47 class MetadataClosure;
48 class NativeCallWrapper;
49 class OopIterateClosure;
50 class ScopeDesc;
51 class xmlStream;
52
53 // This class is used internally by nmethods, to cache
54 // exception/pc/handler information.
55
56 class ExceptionCache : public CHeapObj<mtCode> {
57 friend class VMStructs;
58 private:
59 enum { cache_size = 16 };
60 Klass* _exception_type;
61 address _pc[cache_size];
62 address _handler[cache_size];
63 volatile int _count;
64 ExceptionCache* volatile _next;
65 ExceptionCache* _purge_list_next;
66
67 inline address pc_at(int index);
68 void set_pc_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
69
70 inline address handler_at(int index);
71 void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
72
73 inline int count();
74 // increment_count is only called under lock, but there may be concurrent readers.
75 void increment_count();
76
77 public:
78
79 ExceptionCache(Handle exception, address pc, address handler);
80
81 Klass* exception_type() { return _exception_type; }
82 ExceptionCache* next();
83 void set_next(ExceptionCache *ec);
84 ExceptionCache* purge_list_next() { return _purge_list_next; }
85 void set_purge_list_next(ExceptionCache *ec) { _purge_list_next = ec; }
86
87 address match(Handle exception, address pc);
88 bool match_exception_with_space(Handle exception) ;
89 address test_address(address addr);
90 bool add_address_and_handler(address addr, address handler) ;
91 };
92
93 // cache pc descs found in earlier inquiries
94 class PcDescCache {
95 private:
96 enum { cache_size = 4 };
97 // The array elements MUST be volatile! Several threads may modify
98 // and read from the cache concurrently. find_pc_desc_internal has
99 // returned wrong results. C++ compiler (namely xlC12) may duplicate
100 // C++ field accesses if the elements are not volatile.
101 typedef PcDesc* PcDescPtr;
102 volatile PcDescPtr _pc_descs[cache_size]; // last cache_size pc_descs found
103 public:
104 PcDescCache() { DEBUG_ONLY(_pc_descs[0] = nullptr); }
105 void init_to(PcDesc* initial_pc_desc);
106 PcDesc* find_pc_desc(int pc_offset, bool approximate);
107 void add_pc_desc(PcDesc* pc_desc);
108 PcDesc* last_pc_desc() { return _pc_descs[0]; }
109 };
110
111 class PcDescContainer : public CHeapObj<mtCode> {
112 private:
113 PcDescCache _pc_desc_cache;
114 public:
115 PcDescContainer(PcDesc* initial_pc_desc) { _pc_desc_cache.init_to(initial_pc_desc); }
116
117 PcDesc* find_pc_desc_internal(address pc, bool approximate, address code_begin,
118 PcDesc* lower, PcDesc* upper);
119
120 PcDesc* find_pc_desc(address pc, bool approximate, address code_begin, PcDesc* lower, PcDesc* upper)
121 #ifdef PRODUCT
122 {
123 PcDesc* desc = _pc_desc_cache.last_pc_desc();
124 assert(desc != nullptr, "PcDesc cache should be initialized already");
125 if (desc->pc_offset() == (pc - code_begin)) {
126 // Cached value matched
127 return desc;
128 }
129 return find_pc_desc_internal(pc, approximate, code_begin, lower, upper);
130 }
131 #endif
132 ;
133 };
134
135 // nmethods (native methods) are the compiled code versions of Java methods.
136 //
137 // An nmethod contains:
138 // - Header (the nmethod structure)
139 // - Constant part (doubles, longs and floats used in nmethod)
140 // - Code part:
141 // - Code body
142 // - Exception handler
143 // - Stub code
144 // - OOP table
145 //
146 // As a CodeBlob, an nmethod references [mutable data] allocated on the C heap:
147 // - CodeBlob relocation data
148 // - Metainfo
149 // - JVMCI data
150 //
151 // An nmethod references [immutable data] allocated on C heap:
152 // - Dependency assertions data
153 // - Implicit null table array
154 // - Handler entry point array
155 // - Debugging information:
156 // - Scopes data array
157 // - Scopes pcs array
158 // - JVMCI speculations array
159 // - Nmethod reference counter
160
161 #if INCLUDE_JVMCI
162 class FailedSpeculation;
163 class JVMCINMethodData;
164 #endif
165
166 class nmethod : public CodeBlob {
167 friend class VMStructs;
168 friend class JVMCIVMStructs;
169 friend class CodeCache; // scavengable oops
170 friend class JVMCINMethodData;
171 friend class DeoptimizationScope;
172
173 #define ImmutableDataRefCountSize ((int)sizeof(int))
174
175 private:
176
177 // Used to track in which deoptimize handshake this method will be deoptimized.
178 uint64_t _deoptimization_generation;
179
180 uint64_t _gc_epoch;
181
182 Method* _method;
183
184 // To reduce header size union fields which usages do not overlap.
185 union {
186 // To support simple linked-list chaining of nmethods:
187 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
188 struct {
189 // These are used for compiled synchronized native methods to
190 // locate the owner and stack slot for the BasicLock. They are
191 // needed because there is no debug information for compiled native
192 // wrappers and the oop maps are insufficient to allow
193 // frame::retrieve_receiver() to work. Currently they are expected
194 // to be byte offsets from the Java stack pointer for maximum code
195 // sharing between platforms. JVMTI's GetLocalInstance() uses these
196 // offsets to find the receiver for non-static native wrapper frames.
197 ByteSize _native_receiver_sp_offset;
198 ByteSize _native_basic_lock_sp_offset;
199 };
200 };
201
202 // nmethod's read-only data
203 address _immutable_data;
204
205 PcDescContainer* _pc_desc_container;
206 ExceptionCache* volatile _exception_cache;
207
208 void* _gc_data;
209
210 struct oops_do_mark_link; // Opaque data type.
211 static nmethod* volatile _oops_do_mark_nmethods;
212 oops_do_mark_link* volatile _oops_do_mark_link;
213
214 CompiledICData* _compiled_ic_data;
215
216 // offsets for entry points
217 address _osr_entry_point; // entry point for on stack replacement
218 uint16_t _entry_offset; // entry point with class check
219 uint16_t _verified_entry_offset; // entry point without class check
220 uint16_t _inline_entry_offset; // inline type entry point (unpack all inline type args) with class check
221 uint16_t _verified_inline_entry_offset; // inline type entry point (unpack all inline type args) without class check
222 uint16_t _verified_inline_ro_entry_offset; // inline type entry point (unpack receiver only) without class check
223 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
224 int _immutable_data_size;
225
226 // _consts_offset == _content_offset because SECT_CONSTS is first in code buffer
227
228 int _skipped_instructions_size;
229
230 int _stub_offset;
231
232 // Offsets for different stubs section parts
233 int _exception_offset;
234 // All deoptee's will resume execution at this location described by
235 // this offset.
236 int _deopt_handler_entry_offset;
237 // Offset (from insts_end) of the unwind handler if it exists
238 int16_t _unwind_handler_offset;
239 // Number of arguments passed on the stack
240 uint16_t _num_stack_arg_slots;
241
242 #if INCLUDE_JVMCI
243 // _metadata_size is not specific to JVMCI. In the non-JVMCI case, it can be derived as:
244 // _metadata_size = mutable_data_size - relocation_size
245 int _metadata_size;
246 #endif
247
248 // Offset in immutable data section
249 // _dependencies_offset == 0
250 uint16_t _nul_chk_table_offset;
251 uint16_t _handler_table_offset; // This table could be big in C1 code
252 int _scopes_pcs_offset;
253 int _scopes_data_offset;
254 #if INCLUDE_JVMCI
255 int _speculations_offset;
256 #endif
257 int _immutable_data_ref_count_offset;
258
259 // location in frame (offset for sp) that deopt can store the original
260 // pc during a deopt.
261 int _orig_pc_offset;
262
263 int _compile_id; // which compilation made this nmethod
264 CompLevel _comp_level; // compilation level (s1)
265 CompilerType _compiler_type; // which compiler made this nmethod (u1)
266
267 // Local state used to keep track of whether unloading is happening or not
268 volatile uint8_t _is_unloading_state;
269
270 // Protected by NMethodState_lock
271 volatile signed char _state; // {not_installed, in_use, not_entrant}
272
273 // set during construction
274 uint8_t _has_unsafe_access:1, // May fault due to unsafe access.
275 _has_wide_vectors:1, // Preserve wide vectors at safepoints
276 _has_monitors:1, // Fastpath monitor detection for continuations
277 _has_scoped_access:1, // used by for shared scope closure (scopedMemoryAccess.cpp)
278 _has_flushed_dependencies:1, // Used for maintenance of dependencies (under CodeCache_lock)
279 _is_unlinked:1, // mark during class unloading
280 _load_reported:1; // used by jvmti to track if an event has been posted for this nmethod
281
282 enum DeoptimizationStatus : u1 {
283 not_marked,
284 deoptimize,
285 deoptimize_noupdate,
286 deoptimize_done
287 };
288
289 volatile DeoptimizationStatus _deoptimization_status; // Used for stack deoptimization
290
291 DeoptimizationStatus deoptimization_status() const {
292 return AtomicAccess::load(&_deoptimization_status);
293 }
294
295 // Initialize fields to their default values
296 void init_defaults(CodeBuffer *code_buffer, CodeOffsets* offsets);
297
298 // Post initialization
299 void post_init();
300
301 // For native wrappers
302 nmethod(Method* method,
303 CompilerType type,
304 int nmethod_size,
305 int compile_id,
306 CodeOffsets* offsets,
307 CodeBuffer *code_buffer,
308 int frame_size,
309 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
310 ByteSize basic_lock_sp_offset, /* synchronized natives only */
311 OopMapSet* oop_maps,
312 int mutable_data_size);
313
314 // For normal JIT compiled code
315 nmethod(Method* method,
316 CompilerType type,
317 int nmethod_size,
318 int immutable_data_size,
319 int mutable_data_size,
320 int compile_id,
321 int entry_bci,
322 address immutable_data,
323 CodeOffsets* offsets,
324 int orig_pc_offset,
325 DebugInformationRecorder *recorder,
326 Dependencies* dependencies,
327 CodeBuffer *code_buffer,
328 int frame_size,
329 OopMapSet* oop_maps,
330 ExceptionHandlerTable* handler_table,
331 ImplicitExceptionTable* nul_chk_table,
332 AbstractCompiler* compiler,
333 CompLevel comp_level
334 #if INCLUDE_JVMCI
335 , char* speculations = nullptr,
336 int speculations_len = 0,
337 JVMCINMethodData* jvmci_data = nullptr
338 #endif
339 );
340
341 nmethod(const nmethod &nm);
342
343 // helper methods
344 void* operator new(size_t size, int nmethod_size, int comp_level) throw();
345 void* operator new(size_t size, int nmethod_size, CodeBlobType code_blob_type) throw();
346
347 // For method handle intrinsics: Try MethodNonProfiled, MethodProfiled and NonNMethod.
348 // Attention: Only allow NonNMethod space for special nmethods which don't need to be
349 // findable by nmethod iterators! In particular, they must not contain oops!
350 void* operator new(size_t size, int nmethod_size, bool allow_NonNMethod_space) throw();
351
352 const char* reloc_string_for(u_char* begin, u_char* end);
353
354 bool try_transition(signed char new_state);
355
356 // Returns true if this thread changed the state of the nmethod or
357 // false if another thread performed the transition.
358 bool make_entrant() { Unimplemented(); return false; }
359 void inc_decompile_count();
360
361 // Inform external interfaces that a compiled method has been unloaded
362 void post_compiled_method_unload();
363
364 PcDesc* find_pc_desc(address pc, bool approximate) {
365 if (_pc_desc_container == nullptr) return nullptr; // native method
366 return _pc_desc_container->find_pc_desc(pc, approximate, code_begin(), scopes_pcs_begin(), scopes_pcs_end());
367 }
368
369 // STW two-phase nmethod root processing helpers.
370 //
371 // When determining liveness of a given nmethod to do code cache unloading,
372 // some collectors need to do different things depending on whether the nmethods
373 // need to absolutely be kept alive during root processing; "strong"ly reachable
374 // nmethods are known to be kept alive at root processing, but the liveness of
375 // "weak"ly reachable ones is to be determined later.
376 //
377 // We want to allow strong and weak processing of nmethods by different threads
378 // at the same time without heavy synchronization. Additional constraints are
379 // to make sure that every nmethod is processed a minimal amount of time, and
380 // nmethods themselves are always iterated at most once at a particular time.
381 //
382 // Note that strong processing work must be a superset of weak processing work
383 // for this code to work.
384 //
385 // We store state and claim information in the _oops_do_mark_link member, using
386 // the two LSBs for the state and the remaining upper bits for linking together
387 // nmethods that were already visited.
388 // The last element is self-looped, i.e. points to itself to avoid some special
389 // "end-of-list" sentinel value.
390 //
391 // _oops_do_mark_link special values:
392 //
393 // _oops_do_mark_link == nullptr: the nmethod has not been visited at all yet, i.e.
394 // is Unclaimed.
395 //
396 // For other values, its lowest two bits indicate the following states of the nmethod:
397 //
398 // weak_request (WR): the nmethod has been claimed by a thread for weak processing
399 // weak_done (WD): weak processing has been completed for this nmethod.
400 // strong_request (SR): the nmethod has been found to need strong processing while
401 // being weak processed.
402 // strong_done (SD): strong processing has been completed for this nmethod .
403 //
404 // The following shows the _only_ possible progressions of the _oops_do_mark_link
405 // pointer.
406 //
407 // Given
408 // N as the nmethod
409 // X the current next value of _oops_do_mark_link
410 //
411 // Unclaimed (C)-> N|WR (C)-> X|WD: the nmethod has been processed weakly by
412 // a single thread.
413 // Unclaimed (C)-> N|WR (C)-> X|WD (O)-> X|SD: after weak processing has been
414 // completed (as above) another thread found that the nmethod needs strong
415 // processing after all.
416 // Unclaimed (C)-> N|WR (O)-> N|SR (C)-> X|SD: during weak processing another
417 // thread finds that the nmethod needs strong processing, marks it as such and
418 // terminates. The original thread completes strong processing.
419 // Unclaimed (C)-> N|SD (C)-> X|SD: the nmethod has been processed strongly from
420 // the beginning by a single thread.
421 //
422 // "|" describes the concatenation of bits in _oops_do_mark_link.
423 //
424 // The diagram also describes the threads responsible for changing the nmethod to
425 // the next state by marking the _transition_ with (C) and (O), which mean "current"
426 // and "other" thread respectively.
427 //
428
429 // States used for claiming nmethods during root processing.
430 static const uint claim_weak_request_tag = 0;
431 static const uint claim_weak_done_tag = 1;
432 static const uint claim_strong_request_tag = 2;
433 static const uint claim_strong_done_tag = 3;
434
435 static oops_do_mark_link* mark_link(nmethod* nm, uint tag) {
436 assert(tag <= claim_strong_done_tag, "invalid tag %u", tag);
437 assert(is_aligned(nm, 4), "nmethod pointer must have zero lower two LSB");
438 return (oops_do_mark_link*)(((uintptr_t)nm & ~0x3) | tag);
439 }
440
441 static uint extract_state(oops_do_mark_link* link) {
442 return (uint)((uintptr_t)link & 0x3);
443 }
444
445 static nmethod* extract_nmethod(oops_do_mark_link* link) {
446 return (nmethod*)((uintptr_t)link & ~0x3);
447 }
448
449 void oops_do_log_change(const char* state);
450
451 static bool oops_do_has_weak_request(oops_do_mark_link* next) {
452 return extract_state(next) == claim_weak_request_tag;
453 }
454
455 static bool oops_do_has_any_strong_state(oops_do_mark_link* next) {
456 return extract_state(next) >= claim_strong_request_tag;
457 }
458
459 // Attempt Unclaimed -> N|WR transition. Returns true if successful.
460 bool oops_do_try_claim_weak_request();
461
462 // Attempt Unclaimed -> N|SD transition. Returns the current link.
463 oops_do_mark_link* oops_do_try_claim_strong_done();
464 // Attempt N|WR -> X|WD transition. Returns nullptr if successful, X otherwise.
465 nmethod* oops_do_try_add_to_list_as_weak_done();
466
467 // Attempt X|WD -> N|SR transition. Returns the current link.
468 oops_do_mark_link* oops_do_try_add_strong_request(oops_do_mark_link* next);
469 // Attempt X|WD -> X|SD transition. Returns true if successful.
470 bool oops_do_try_claim_weak_done_as_strong_done(oops_do_mark_link* next);
471
472 // Do the N|SD -> X|SD transition.
473 void oops_do_add_to_list_as_strong_done();
474
475 // Sets this nmethod as strongly claimed (as part of N|SD -> X|SD and N|SR -> X|SD
476 // transitions).
477 void oops_do_set_strong_done(nmethod* old_head);
478
479 public:
480 // If you change anything in this enum please patch
481 // vmStructs_jvmci.cpp accordingly.
482 enum class InvalidationReason : s1 {
483 NOT_INVALIDATED = -1,
484 C1_CODEPATCH,
485 C1_DEOPTIMIZE,
486 C1_DEOPTIMIZE_FOR_PATCHING,
487 C1_PREDICATE_FAILED_TRAP,
488 CI_REPLAY,
489 UNLOADING,
490 UNLOADING_COLD,
491 JVMCI_INVALIDATE,
492 JVMCI_MATERIALIZE_VIRTUAL_OBJECT,
493 JVMCI_REPLACED_WITH_NEW_CODE,
494 JVMCI_REPROFILE,
495 MARKED_FOR_DEOPTIMIZATION,
496 MISSING_EXCEPTION_HANDLER,
497 NOT_USED,
498 OSR_INVALIDATION_BACK_BRANCH,
499 OSR_INVALIDATION_FOR_COMPILING_WITH_C1,
500 OSR_INVALIDATION_OF_LOWER_LEVEL,
501 SET_NATIVE_FUNCTION,
502 UNCOMMON_TRAP,
503 WHITEBOX_DEOPTIMIZATION,
504 ZOMBIE,
505 RELOCATED,
506 INVALIDATION_REASONS_COUNT
507 };
508
509
510 static const char* invalidation_reason_to_string(InvalidationReason invalidation_reason) {
511 switch (invalidation_reason) {
512 case InvalidationReason::C1_CODEPATCH:
513 return "C1 code patch";
514 case InvalidationReason::C1_DEOPTIMIZE:
515 return "C1 deoptimized";
516 case InvalidationReason::C1_DEOPTIMIZE_FOR_PATCHING:
517 return "C1 deoptimize for patching";
518 case InvalidationReason::C1_PREDICATE_FAILED_TRAP:
519 return "C1 predicate failed trap";
520 case InvalidationReason::CI_REPLAY:
521 return "CI replay";
522 case InvalidationReason::JVMCI_INVALIDATE:
523 return "JVMCI invalidate";
524 case InvalidationReason::JVMCI_MATERIALIZE_VIRTUAL_OBJECT:
525 return "JVMCI materialize virtual object";
526 case InvalidationReason::JVMCI_REPLACED_WITH_NEW_CODE:
527 return "JVMCI replaced with new code";
528 case InvalidationReason::JVMCI_REPROFILE:
529 return "JVMCI reprofile";
530 case InvalidationReason::MARKED_FOR_DEOPTIMIZATION:
531 return "marked for deoptimization";
532 case InvalidationReason::MISSING_EXCEPTION_HANDLER:
533 return "missing exception handler";
534 case InvalidationReason::NOT_USED:
535 return "not used";
536 case InvalidationReason::OSR_INVALIDATION_BACK_BRANCH:
537 return "OSR invalidation back branch";
538 case InvalidationReason::OSR_INVALIDATION_FOR_COMPILING_WITH_C1:
539 return "OSR invalidation for compiling with C1";
540 case InvalidationReason::OSR_INVALIDATION_OF_LOWER_LEVEL:
541 return "OSR invalidation of lower level";
542 case InvalidationReason::SET_NATIVE_FUNCTION:
543 return "set native function";
544 case InvalidationReason::UNCOMMON_TRAP:
545 return "uncommon trap";
546 case InvalidationReason::WHITEBOX_DEOPTIMIZATION:
547 return "whitebox deoptimization";
548 case InvalidationReason::ZOMBIE:
549 return "zombie";
550 case InvalidationReason::RELOCATED:
551 return "relocated";
552 default: {
553 assert(false, "Unhandled reason");
554 return "Unknown";
555 }
556 }
557 }
558
559 // create nmethod with entry_bci
560 static nmethod* new_nmethod(const methodHandle& method,
561 int compile_id,
562 int entry_bci,
563 CodeOffsets* offsets,
564 int orig_pc_offset,
565 DebugInformationRecorder* recorder,
566 Dependencies* dependencies,
567 CodeBuffer *code_buffer,
568 int frame_size,
569 OopMapSet* oop_maps,
570 ExceptionHandlerTable* handler_table,
571 ImplicitExceptionTable* nul_chk_table,
572 AbstractCompiler* compiler,
573 CompLevel comp_level
574 #if INCLUDE_JVMCI
575 , char* speculations = nullptr,
576 int speculations_len = 0,
577 JVMCINMethodData* jvmci_data = nullptr
578 #endif
579 );
580
581 // Relocate the nmethod to the code heap identified by code_blob_type.
582 // Returns nullptr if the code heap does not have enough space, the
583 // nmethod is unrelocatable, or the nmethod is invalidated during relocation,
584 // otherwise the relocated nmethod. The original nmethod will be marked not entrant.
585 nmethod* relocate(CodeBlobType code_blob_type);
586
587 static nmethod* new_native_nmethod(const methodHandle& method,
588 int compile_id,
589 CodeBuffer *code_buffer,
590 int vep_offset,
591 int frame_complete,
592 int frame_size,
593 ByteSize receiver_sp_offset,
594 ByteSize basic_lock_sp_offset,
595 OopMapSet* oop_maps,
596 int exception_handler = -1);
597
598 Method* method () const { return _method; }
599 bool is_native_method() const { return _method != nullptr && _method->is_native(); }
600 bool is_java_method () const { return _method != nullptr && !_method->is_native(); }
601 bool is_osr_method () const { return _entry_bci != InvocationEntryBci; }
602
603 bool is_relocatable();
604
605 // Compiler task identification. Note that all OSR methods
606 // are numbered in an independent sequence if CICountOSR is true,
607 // and native method wrappers are also numbered independently if
608 // CICountNative is true.
609 int compile_id() const { return _compile_id; }
610 const char* compile_kind() const;
611
612 inline bool is_compiled_by_c1 () const { return _compiler_type == compiler_c1; }
613 inline bool is_compiled_by_c2 () const { return _compiler_type == compiler_c2; }
614 inline bool is_compiled_by_jvmci() const { return _compiler_type == compiler_jvmci; }
615 CompilerType compiler_type () const { return _compiler_type; }
616 const char* compiler_name () const;
617
618 // boundaries for different parts
619 address consts_begin () const { return content_begin(); }
620 address consts_end () const { return code_begin() ; }
621 address insts_begin () const { return code_begin() ; }
622 address insts_end () const { return header_begin() + _stub_offset ; }
623 address stub_begin () const { return header_begin() + _stub_offset ; }
624 address stub_end () const { return code_end() ; }
625 address exception_begin () const { return header_begin() + _exception_offset ; }
626 address deopt_handler_entry () const { return header_begin() + _deopt_handler_entry_offset ; }
627 address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (insts_end() - _unwind_handler_offset) : nullptr; }
628 oop* oops_begin () const { return (oop*) data_begin(); }
629 oop* oops_end () const { return (oop*) data_end(); }
630
631 // mutable data
632 Metadata** metadata_begin () const { return (Metadata**) (mutable_data_begin() + _relocation_size); }
633 #if INCLUDE_JVMCI
634 Metadata** metadata_end () const { return (Metadata**) (mutable_data_begin() + _relocation_size + _metadata_size); }
635 address jvmci_data_begin () const { return mutable_data_begin() + _relocation_size + _metadata_size; }
636 address jvmci_data_end () const { return mutable_data_end(); }
637 #else
638 Metadata** metadata_end () const { return (Metadata**) mutable_data_end(); }
639 #endif
640
641 // immutable data
642 address immutable_data_begin () const { return _immutable_data; }
643 address immutable_data_end () const { return _immutable_data + _immutable_data_size ; }
644 address dependencies_begin () const { return _immutable_data; }
645 address dependencies_end () const { return _immutable_data + _nul_chk_table_offset; }
646 address nul_chk_table_begin () const { return _immutable_data + _nul_chk_table_offset; }
647 address nul_chk_table_end () const { return _immutable_data + _handler_table_offset; }
648 address handler_table_begin () const { return _immutable_data + _handler_table_offset; }
649 address handler_table_end () const { return _immutable_data + _scopes_pcs_offset ; }
650 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(_immutable_data + _scopes_pcs_offset) ; }
651 PcDesc* scopes_pcs_end () const { return (PcDesc*)(_immutable_data + _scopes_data_offset) ; }
652 address scopes_data_begin () const { return _immutable_data + _scopes_data_offset ; }
653
654 #if INCLUDE_JVMCI
655 address scopes_data_end () const { return _immutable_data + _speculations_offset ; }
656 address speculations_begin () const { return _immutable_data + _speculations_offset ; }
657 address speculations_end () const { return _immutable_data + _immutable_data_ref_count_offset ; }
658 #else
659 address scopes_data_end () const { return _immutable_data + _immutable_data_ref_count_offset ; }
660 #endif
661 address immutable_data_ref_count_begin () const { return _immutable_data + _immutable_data_ref_count_offset ; }
662
663 // Sizes
664 int immutable_data_size() const { return _immutable_data_size; }
665 int consts_size () const { return int( consts_end () - consts_begin ()); }
666 int insts_size () const { return int( insts_end () - insts_begin ()); }
667 int stub_size () const { return int( stub_end () - stub_begin ()); }
668 int oops_size () const { return int((address) oops_end () - (address) oops_begin ()); }
669 int metadata_size () const { return int((address) metadata_end () - (address) metadata_begin ()); }
670 int scopes_data_size () const { return int( scopes_data_end () - scopes_data_begin ()); }
671 int scopes_pcs_size () const { return int((intptr_t)scopes_pcs_end () - (intptr_t)scopes_pcs_begin ()); }
672 int dependencies_size () const { return int( dependencies_end () - dependencies_begin ()); }
673 int handler_table_size () const { return int( handler_table_end() - handler_table_begin()); }
674 int nul_chk_table_size () const { return int( nul_chk_table_end() - nul_chk_table_begin()); }
675 #if INCLUDE_JVMCI
676 int speculations_size () const { return int( speculations_end () - speculations_begin ()); }
677 int jvmci_data_size () const { return int( jvmci_data_end () - jvmci_data_begin ()); }
678 #endif
679
680 int oops_count() const { assert(oops_size() % oopSize == 0, ""); return (oops_size() / oopSize) + 1; }
681 int metadata_count() const { assert(metadata_size() % wordSize == 0, ""); return (metadata_size() / wordSize) + 1; }
682
683 int skipped_instructions_size () const { return _skipped_instructions_size; }
684 int total_size() const;
685
686 // Containment
687 bool consts_contains (address addr) const { return consts_begin () <= addr && addr < consts_end (); }
688 // Returns true if a given address is in the 'insts' section. The method
689 // insts_contains_inclusive() is end-inclusive.
690 bool insts_contains (address addr) const { return insts_begin () <= addr && addr < insts_end (); }
691 bool insts_contains_inclusive(address addr) const { return insts_begin () <= addr && addr <= insts_end (); }
692 bool stub_contains (address addr) const { return stub_begin () <= addr && addr < stub_end (); }
693 bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
694 bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); }
695 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
696 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
697 bool handler_table_contains (address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
698 bool nul_chk_table_contains (address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
699
700 // entry points
701 address entry_point() const { return code_begin() + _entry_offset; } // normal entry point
702 address verified_entry_point() const { return code_begin() + _verified_entry_offset; } // if klass is correct
703 address inline_entry_point() const { return code_begin() + _inline_entry_offset; } // inline type entry point (unpack all inline type args)
704 address verified_inline_entry_point() const { return code_begin() + _verified_inline_entry_offset; } // inline type entry point (unpack all inline type args) without class check
705 address verified_inline_ro_entry_point() const { return code_begin() + _verified_inline_ro_entry_offset; } // inline type entry point (only unpack receiver) without class check
706
707 enum : signed char { not_installed = -1, // in construction, only the owner doing the construction is
708 // allowed to advance state
709 in_use = 0, // executable nmethod
710 not_entrant = 1 // marked for deoptimization but activations may still exist
711 };
712
713 // flag accessing and manipulation
714 bool is_not_installed() const { return _state == not_installed; }
715 bool is_in_use() const { return _state <= in_use; }
716 bool is_not_entrant() const { return _state == not_entrant; }
717 int get_state() const { return _state; }
718
719 void clear_unloading_state();
720 // Heuristically deduce an nmethod isn't worth keeping around
721 bool is_cold();
722 bool is_unloading();
723 void do_unloading(bool unloading_occurred);
724
725 bool make_in_use() {
726 return try_transition(in_use);
727 }
728 // Make the nmethod non entrant. The nmethod will continue to be
729 // alive. It is used when an uncommon trap happens. Returns true
730 // if this thread changed the state of the nmethod or false if
731 // another thread performed the transition.
732 bool make_not_entrant(InvalidationReason invalidation_reason);
733 bool make_not_used() { return make_not_entrant(InvalidationReason::NOT_USED); }
734
735 bool is_marked_for_deoptimization() const { return deoptimization_status() != not_marked; }
736 bool has_been_deoptimized() const { return deoptimization_status() == deoptimize_done; }
737 void set_deoptimized_done();
738
739 bool update_recompile_counts() const {
740 // Update recompile counts when either the update is explicitly requested (deoptimize)
741 // or the nmethod is not marked for deoptimization at all (not_marked).
742 // The latter happens during uncommon traps when deoptimized nmethod is made not entrant.
743 DeoptimizationStatus status = deoptimization_status();
744 return status != deoptimize_noupdate && status != deoptimize_done;
745 }
746
747 // tells whether frames described by this nmethod can be deoptimized
748 // note: native wrappers cannot be deoptimized.
749 bool can_be_deoptimized() const { return is_java_method(); }
750
751 bool has_dependencies() { return dependencies_size() != 0; }
752 void print_dependencies_on(outputStream* out) PRODUCT_RETURN;
753 void flush_dependencies();
754
755 template<typename T>
756 T* gc_data() const { return reinterpret_cast<T*>(_gc_data); }
757 template<typename T>
758 void set_gc_data(T* gc_data) { _gc_data = reinterpret_cast<void*>(gc_data); }
759
760 bool has_unsafe_access() const { return _has_unsafe_access; }
761 void set_has_unsafe_access(bool z) { _has_unsafe_access = z; }
762
763 bool has_monitors() const { return _has_monitors; }
764 void set_has_monitors(bool z) { _has_monitors = z; }
765
766 bool has_scoped_access() const { return _has_scoped_access; }
767 void set_has_scoped_access(bool z) { _has_scoped_access = z; }
768
769 bool has_wide_vectors() const { return _has_wide_vectors; }
770 void set_has_wide_vectors(bool z) { _has_wide_vectors = z; }
771
772 bool needs_stack_repair() const {
773 if (is_compiled_by_c1()) {
774 return method()->c1_needs_stack_repair();
775 } else if (is_compiled_by_c2()) {
776 return method()->c2_needs_stack_repair();
777 } else {
778 return false;
779 }
780 }
781
782 bool has_flushed_dependencies() const { return _has_flushed_dependencies; }
783 void set_has_flushed_dependencies(bool z) {
784 assert(!has_flushed_dependencies(), "should only happen once");
785 _has_flushed_dependencies = z;
786 }
787
788 bool is_unlinked() const { return _is_unlinked; }
789 void set_is_unlinked() {
790 assert(!_is_unlinked, "already unlinked");
791 _is_unlinked = true;
792 }
793
794 int comp_level() const { return _comp_level; }
795
796 // Support for oops in scopes and relocs:
797 // Note: index 0 is reserved for null.
798 oop oop_at(int index) const;
799 oop oop_at_phantom(int index) const; // phantom reference
800 oop* oop_addr_at(int index) const { // for GC
801 // relocation indexes are biased by 1 (because 0 is reserved)
802 assert(index > 0 && index <= oops_count(), "must be a valid non-zero index");
803 return &oops_begin()[index - 1];
804 }
805
806 // Support for meta data in scopes and relocs:
807 // Note: index 0 is reserved for null.
808 Metadata* metadata_at(int index) const { return index == 0 ? nullptr: *metadata_addr_at(index); }
809 Metadata** metadata_addr_at(int index) const { // for GC
810 // relocation indexes are biased by 1 (because 0 is reserved)
811 assert(index > 0 && index <= metadata_count(), "must be a valid non-zero index");
812 return &metadata_begin()[index - 1];
813 }
814
815 void copy_values(GrowableArray<jobject>* oops);
816 void copy_values(GrowableArray<Metadata*>* metadata);
817 void copy_values(GrowableArray<address>* metadata) {} // Nothing to do
818
819 // Relocation support
820 private:
821 void fix_oop_relocations(address begin, address end, bool initialize_immediates);
822 inline void initialize_immediate_oop(oop* dest, jobject handle);
823
824 protected:
825 address oops_reloc_begin() const;
826
827 public:
828 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
829 void fix_oop_relocations() { fix_oop_relocations(nullptr, nullptr, false); }
830
831 bool is_at_poll_return(address pc);
832 bool is_at_poll_or_poll_return(address pc);
833
834 protected:
835 // Exception cache support
836 // Note: _exception_cache may be read and cleaned concurrently.
837 ExceptionCache* exception_cache() const { return _exception_cache; }
838 ExceptionCache* exception_cache_acquire() const;
839
840 public:
841 address handler_for_exception_and_pc(Handle exception, address pc);
842 void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
843 void clean_exception_cache();
844
845 void add_exception_cache_entry(ExceptionCache* new_entry);
846 ExceptionCache* exception_cache_entry_for_exception(Handle exception);
847
848
849 // Deopt
850 // Return true is the PC is one would expect if the frame is being deopted.
851 inline bool is_deopt_pc(address pc);
852 inline bool is_deopt_entry(address pc);
853
854 // Accessor/mutator for the original pc of a frame before a frame was deopted.
855 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
856 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
857
858 const char* state() const;
859
860 bool inlinecache_check_contains(address addr) const {
861 return (addr >= code_begin() && (addr < verified_entry_point() || addr < verified_inline_entry_point()));
862 }
863
864 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f);
865
866 // implicit exceptions support
867 address continuation_for_implicit_div0_exception(address pc) { return continuation_for_implicit_exception(pc, true); }
868 address continuation_for_implicit_null_exception(address pc) { return continuation_for_implicit_exception(pc, false); }
869
870 // Inline cache support for class unloading and nmethod unloading
871 private:
872 void cleanup_inline_caches_impl(bool unloading_occurred, bool clean_all);
873
874 address continuation_for_implicit_exception(address pc, bool for_div0_check);
875
876 public:
877 // Serial version used by whitebox test
878 void cleanup_inline_caches_whitebox();
879
880 void clear_inline_caches();
881
882 // Execute nmethod barrier code, as if entering through nmethod call.
883 void run_nmethod_entry_barrier();
884
885 void verify_oop_relocations();
886
887 bool has_evol_metadata();
888
889 Method* attached_method(address call_pc);
890 Method* attached_method_before_pc(address pc);
891
892 // GC unloading support
893 // Cleans unloaded klasses and unloaded nmethods in inline caches
894
895 void unload_nmethod_caches(bool class_unloading_occurred);
896
897 void unlink_from_method();
898
899 // On-stack replacement support
900 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
901 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
902 nmethod* osr_link() const { return _osr_link; }
903 void set_osr_link(nmethod *n) { _osr_link = n; }
904 void invalidate_osr_method();
905
906 int num_stack_arg_slots(bool rounded = true) const {
907 return rounded ? align_up(_num_stack_arg_slots, 2) : _num_stack_arg_slots;
908 }
909
910 // Verify calls to dead methods have been cleaned.
911 void verify_clean_inline_caches();
912
913 // Unlink this nmethod from the system
914 void unlink();
915
916 // Deallocate this nmethod - called by the GC
917 void purge(bool unregister_nmethod);
918
919 // See comment at definition of _last_seen_on_stack
920 void mark_as_maybe_on_stack();
921 bool is_maybe_on_stack();
922
923 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
924 void set_method(Method* method) { _method = method; }
925
926 #if INCLUDE_JVMCI
927 // Gets the JVMCI name of this nmethod.
928 const char* jvmci_name();
929
930 // Records the pending failed speculation in the
931 // JVMCI speculation log associated with this nmethod.
932 void update_speculation(JavaThread* thread);
933
934 // Gets the data specific to a JVMCI compiled method.
935 // This returns a non-nullptr value iff this nmethod was
936 // compiled by the JVMCI compiler.
937 JVMCINMethodData* jvmci_nmethod_data() const {
938 return jvmci_data_size() == 0 ? nullptr : (JVMCINMethodData*) jvmci_data_begin();
939 }
940
941 // Returns true if the runtime should NOT collect deoptimization profile for a JVMCI
942 // compiled method
943 bool jvmci_skip_profile_deopt() const;
944 #endif
945
946 void oops_do(OopClosure* f);
947
948 // All-in-one claiming of nmethods: returns true if the caller successfully claimed that
949 // nmethod.
950 bool oops_do_try_claim();
951
952 // Loom support for following nmethods on the stack
953 void follow_nmethod(OopIterateClosure* cl);
954
955 // Class containing callbacks for the oops_do_process_weak/strong() methods
956 // below.
957 class OopsDoProcessor {
958 public:
959 // Process the oops of the given nmethod based on whether it has been called
960 // in a weak or strong processing context, i.e. apply either weak or strong
961 // work on it.
962 virtual void do_regular_processing(nmethod* nm) = 0;
963 // Assuming that the oops of the given nmethod has already been its weak
964 // processing applied, apply the remaining strong processing part.
965 virtual void do_remaining_strong_processing(nmethod* nm) = 0;
966 };
967
968 // The following two methods do the work corresponding to weak/strong nmethod
969 // processing.
970 void oops_do_process_weak(OopsDoProcessor* p);
971 void oops_do_process_strong(OopsDoProcessor* p);
972
973 static void oops_do_marking_prologue();
974 static void oops_do_marking_epilogue();
975
976 private:
977 ScopeDesc* scope_desc_in(address begin, address end);
978
979 address* orig_pc_addr(const frame* fr);
980
981 // used by jvmti to track if the load events has been reported
982 bool load_reported() const { return _load_reported; }
983 void set_load_reported() { _load_reported = true; }
984
985 inline void init_immutable_data_ref_count() {
986 assert(is_not_installed(), "should be called in nmethod constructor");
987 *((int*)immutable_data_ref_count_begin()) = 1;
988 }
989
990 inline int inc_immutable_data_ref_count() {
991 assert_lock_strong(CodeCache_lock);
992 int* ref_count = (int*)immutable_data_ref_count_begin();
993 assert(*ref_count > 0, "Must be positive");
994 return ++(*ref_count);
995 }
996
997 inline int dec_immutable_data_ref_count() {
998 assert_lock_strong(CodeCache_lock);
999 int* ref_count = (int*)immutable_data_ref_count_begin();
1000 assert(*ref_count > 0, "Must be positive");
1001 return --(*ref_count);
1002 }
1003
1004 static void add_delayed_compiled_method_load_event(nmethod* nm) NOT_CDS_RETURN;
1005
1006 public:
1007 // ScopeDesc retrieval operation
1008 PcDesc* pc_desc_at(address pc) { return find_pc_desc(pc, false); }
1009 // pc_desc_near returns the first PcDesc at or after the given pc.
1010 PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
1011
1012 // ScopeDesc for an instruction
1013 ScopeDesc* scope_desc_at(address pc);
1014 ScopeDesc* scope_desc_near(address pc);
1015
1016 // copying of debugging information
1017 void copy_scopes_pcs(PcDesc* pcs, int count);
1018 void copy_scopes_data(address buffer, int size);
1019
1020 int orig_pc_offset() { return _orig_pc_offset; }
1021
1022 // Post successful compilation
1023 void post_compiled_method(CompileTask* task);
1024
1025 // jvmti support:
1026 void post_compiled_method_load_event(JvmtiThreadState* state = nullptr);
1027
1028 // verify operations
1029 void verify();
1030 void verify_scopes();
1031 void verify_interrupt_point(address interrupt_point, bool is_inline_cache);
1032
1033 // Disassemble this nmethod with additional debug information, e.g. information about blocks.
1034 void decode2(outputStream* st) const;
1035 void print_constant_pool(outputStream* st);
1036
1037 // Avoid hiding of parent's 'decode(outputStream*)' method.
1038 void decode(outputStream* st) const { decode2(st); } // just delegate here.
1039
1040 // AOT cache support
1041 static void post_delayed_compiled_method_load_events() NOT_CDS_RETURN;
1042
1043 // printing support
1044 void print_on_impl(outputStream* st) const;
1045 void print_code();
1046 void print_value_on_impl(outputStream* st) const;
1047 void print_code_snippet(outputStream* st, address addr) const;
1048
1049 #if defined(SUPPORT_DATA_STRUCTS)
1050 // print output in opt build for disassembler library
1051 void print_relocations() PRODUCT_RETURN;
1052 void print_pcs_on(outputStream* st);
1053 void print_scopes() { print_scopes_on(tty); }
1054 void print_scopes_on(outputStream* st) PRODUCT_RETURN;
1055 void print_handler_table();
1056 void print_nul_chk_table();
1057 void print_recorded_oop(int log_n, int index);
1058 void print_recorded_oops();
1059 void print_recorded_metadata();
1060
1061 void print_oops(outputStream* st); // oops from the underlying CodeBlob.
1062 void print_metadata(outputStream* st); // metadata in metadata pool.
1063 #else
1064 void print_pcs_on(outputStream* st) { return; }
1065 #endif
1066
1067 void print_calls(outputStream* st) PRODUCT_RETURN;
1068 static void print_statistics() PRODUCT_RETURN;
1069
1070 void maybe_print_nmethod(const DirectiveSet* directive);
1071 void print_nmethod(bool print_code);
1072
1073 void print_on_with_msg(outputStream* st, const char* msg) const;
1074
1075 // Logging
1076 void log_identity(xmlStream* log) const;
1077 void log_new_nmethod() const;
1078 void log_relocated_nmethod(nmethod* original) const;
1079 void log_state_change(InvalidationReason invalidation_reason) const;
1080
1081 // Prints block-level comments, including nmethod specific block labels:
1082 void print_nmethod_labels(outputStream* stream, address block_begin, bool print_section_labels=true) const;
1083 const char* nmethod_section_label(address pos) const;
1084
1085 // returns whether this nmethod has code comments.
1086 bool has_code_comment(address begin, address end);
1087 // Prints a comment for one native instruction (reloc info, pc desc)
1088 void print_code_comment_on(outputStream* st, int column, address begin, address end);
1089
1090 // tells if this compiled method is dependent on the given changes,
1091 // and the changes have invalidated it
1092 bool check_dependency_on(DepChange& changes);
1093
1094 // Tells if this compiled method is dependent on the given method.
1095 // Returns true if this nmethod corresponds to the given method as well.
1096 // It is used for fast breakpoint support and updating the calling convention
1097 // in case of mismatch.
1098 bool is_dependent_on_method(Method* dependee);
1099
1100 // JVMTI's GetLocalInstance() support
1101 ByteSize native_receiver_sp_offset() {
1102 assert(is_native_method(), "sanity");
1103 return _native_receiver_sp_offset;
1104 }
1105 ByteSize native_basic_lock_sp_offset() {
1106 assert(is_native_method(), "sanity");
1107 return _native_basic_lock_sp_offset;
1108 }
1109
1110 // support for code generation
1111 static ByteSize osr_entry_point_offset() { return byte_offset_of(nmethod, _osr_entry_point); }
1112 static ByteSize state_offset() { return byte_offset_of(nmethod, _state); }
1113
1114 void metadata_do(MetadataClosure* f);
1115
1116 address call_instruction_address(address pc) const;
1117
1118 void make_deoptimized();
1119 void finalize_relocations();
1120
1121 class Vptr : public CodeBlob::Vptr {
1122 void print_on(const CodeBlob* instance, outputStream* st) const override {
1123 ttyLocker ttyl;
1124 instance->as_nmethod()->print_on_impl(st);
1125 }
1126 void print_value_on(const CodeBlob* instance, outputStream* st) const override {
1127 instance->as_nmethod()->print_value_on_impl(st);
1128 }
1129 };
1130
1131 static const Vptr _vpntr;
1132 };
1133
1134 struct NMethodMarkingScope : StackObj {
1135 NMethodMarkingScope() {
1136 nmethod::oops_do_marking_prologue();
1137 }
1138 ~NMethodMarkingScope() {
1139 nmethod::oops_do_marking_epilogue();
1140 }
1141 };
1142
1143 #endif // SHARE_CODE_NMETHOD_HPP