1 /*
2 * Copyright (c) 1998, 2016, 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_VM_CODE_CODEBLOB_HPP
26 #define SHARE_VM_CODE_CODEBLOB_HPP
27
28 #include "asm/codeBuffer.hpp"
29 #include "compiler/compilerDefinitions.hpp"
30 #include "compiler/oopMap.hpp"
31 #include "runtime/frame.hpp"
32 #include "runtime/handles.hpp"
33 #include "utilities/macros.hpp"
34
35 // CodeBlob Types
36 // Used in the CodeCache to assign CodeBlobs to different CodeHeaps
37 struct CodeBlobType {
38 enum {
39 MethodNonProfiled = 0, // Execution level 1 and 4 (non-profiled) nmethods (including native nmethods)
40 MethodProfiled = 1, // Execution level 2 and 3 (profiled) nmethods
41 NonNMethod = 2, // Non-nmethods like Buffers, Adapters and Runtime Stubs
42 All = 3, // All types (No code cache segmentation)
43 Pregenerated = 4, // Special blobs, managed by CodeCacheExtensions
44 NumTypes = 5 // Number of CodeBlobTypes
45 };
46 };
47
48 // CodeBlob - superclass for all entries in the CodeCache.
49 //
50 // Subtypes are:
51 // CompiledMethod : Compiled Java methods (include method that calls to native code)
52 // nmethod : JIT Compiled Java methods
53 // RuntimeBlob : Non-compiled method code; generated glue code
54 // RuntimeStub : Call to VM runtime methods
55 // DeoptimizationBlob : Used for deoptimization
56 // ExceptionBlob : Used for stack unrolling
57 // SafepointBlob : Used to handle illegal instruction exceptions
58 //
59 //
60 // Layout:
61 // - header
62 // - relocation
63 // - content space
64 // - instruction space
65 // - data space
66
67
68 class CodeBlobLayout;
69
70 class CodeBlob VALUE_OBJ_CLASS_SPEC {
71 friend class VMStructs;
72 friend class JVMCIVMStructs;
73 friend class CodeCacheDumper;
74
75 protected:
76
77 const CompilerType _type; // CompilerType
78 int _size; // total size of CodeBlob in bytes
79 int _header_size; // size of header (depends on subclass)
80 int _frame_complete_offset; // instruction offsets in [0.._frame_complete_offset) have
81 // not finished setting up their frame. Beware of pc's in
82 // that range. There is a similar range(s) on returns
83 // which we don't detect.
84 int _data_offset; // offset to where data region begins
85 int _frame_size; // size of stack frame
86
87 address _code_begin;
88 address _code_end;
89 address _content_begin; // address to where content region begins (this includes consts, insts, stubs)
90 // address _content_end - not required, for all CodeBlobs _code_end == _content_end for now
91 address _data_end;
92 address _relocation_begin;
93 address _relocation_end;
94
95 ImmutableOopMapSet* _oop_maps; // OopMap for this CodeBlob
96 bool _caller_must_gc_arguments;
97 CodeStrings _strings;
98 const char* _name;
99 S390_ONLY(int _ctable_offset;)
100
101 CodeBlob(const char* name, CompilerType type, const CodeBlobLayout& layout, int frame_complete_offset, int frame_size, ImmutableOopMapSet* oop_maps, bool caller_must_gc_arguments);
102 CodeBlob(const char* name, CompilerType type, const CodeBlobLayout& layout, CodeBuffer* cb, int frame_complete_offset, int frame_size, OopMapSet* oop_maps, bool caller_must_gc_arguments);
103 public:
104 // Returns the space needed for CodeBlob
105 static unsigned int allocation_size(CodeBuffer* cb, int header_size);
106 static unsigned int align_code_offset(int offset);
107
108 // Deletion
109 virtual void flush();
110
111 // Typing
112 virtual bool is_buffer_blob() const { return false; }
113 virtual bool is_nmethod() const { return false; }
114 virtual bool is_runtime_stub() const { return false; }
115 virtual bool is_deoptimization_stub() const { return false; }
116 virtual bool is_uncommon_trap_stub() const { return false; }
117 virtual bool is_exception_stub() const { return false; }
118 virtual bool is_safepoint_stub() const { return false; }
119 virtual bool is_adapter_blob() const { return false; }
120 virtual bool is_method_handles_adapter_blob() const { return false; }
121 virtual bool is_compiled() const { return false; }
122
123 inline bool is_compiled_by_c1() const { return _type == compiler_c1; };
124 inline bool is_compiled_by_c2() const { return _type == compiler_c2; };
125 inline bool is_compiled_by_jvmci() const { return _type == compiler_jvmci; };
126 inline bool is_compiled_by_shark() const { return _type == compiler_shark; };
127 const char* compiler_name() const;
128
129 // Casting
130 nmethod* as_nmethod_or_null() { return is_nmethod() ? (nmethod*) this : NULL; }
131 nmethod* as_nmethod() { assert(is_nmethod(), "must be nmethod"); return (nmethod*) this; }
132 CompiledMethod* as_compiled_method_or_null() { return is_compiled() ? (CompiledMethod*) this : NULL; }
133 CompiledMethod* as_compiled_method() { assert(is_compiled(), "must be compiled"); return (CompiledMethod*) this; }
134
135 // Boundaries
136 address header_begin() const { return (address) this; }
137 relocInfo* relocation_begin() const { return (relocInfo*) _relocation_begin; };
138 relocInfo* relocation_end() const { return (relocInfo*) _relocation_end; }
139 address content_begin() const { return _content_begin; }
140 address content_end() const { return _code_end; } // _code_end == _content_end is true for all types of blobs for now, it is also checked in the constructor
141 address code_begin() const { return _code_begin; }
142 address code_end() const { return _code_end; }
143 address data_end() const { return _data_end; }
144
145 // This field holds the beginning of the const section in the old code buffer.
146 // It is needed to fix relocations of pc-relative loads when resizing the
147 // the constant pool or moving it.
148 S390_ONLY(address ctable_begin() const { return header_begin() + _ctable_offset; })
149 void set_ctable_begin(address ctable) { S390_ONLY(_ctable_offset = ctable - header_begin();) }
150
151 // Sizes
152 int size() const { return _size; }
153 int header_size() const { return _header_size; }
154 int relocation_size() const { return (address) relocation_end() - (address) relocation_begin(); }
155 int content_size() const { return content_end() - content_begin(); }
156 int code_size() const { return code_end() - code_begin(); }
157
158 // Containment
159 bool blob_contains(address addr) const { return header_begin() <= addr && addr < data_end(); }
160 bool code_contains(address addr) const { return code_begin() <= addr && addr < code_end(); }
161 bool contains(address addr) const { return content_begin() <= addr && addr < content_end(); }
162 bool is_frame_complete_at(address addr) const { return code_contains(addr) && addr >= code_begin() + _frame_complete_offset; }
163
164 // CodeCache support: really only used by the nmethods, but in order to get
165 // asserts and certain bookkeeping to work in the CodeCache they are defined
166 // virtual here.
167 virtual bool is_zombie() const { return false; }
168 virtual bool is_locked_by_vm() const { return false; }
169
170 virtual bool is_unloaded() const { return false; }
171 virtual bool is_not_entrant() const { return false; }
172
173 // GC support
174 virtual bool is_alive() const = 0;
175
176 // OopMap for frame
177 ImmutableOopMapSet* oop_maps() const { return _oop_maps; }
178 void set_oop_maps(OopMapSet* p);
179 const ImmutableOopMap* oop_map_for_return_address(address return_address);
180 virtual void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f) = 0;
181
182 // Frame support
183 int frame_size() const { return _frame_size; }
184 void set_frame_size(int size) { _frame_size = size; }
185
186 // Returns true, if the next frame is responsible for GC'ing oops passed as arguments
187 bool caller_must_gc_arguments(JavaThread* thread) const { return _caller_must_gc_arguments; }
188
189 // Naming
190 const char* name() const { return _name; }
191 void set_name(const char* name) { _name = name; }
192
193 // Debugging
194 virtual void verify() = 0;
195 virtual void print() const { print_on(tty); };
196 virtual void print_on(outputStream* st) const;
197 virtual void print_value_on(outputStream* st) const;
198 void print_code();
199
200 // Print the comment associated with offset on stream, if there is one
201 virtual void print_block_comment(outputStream* stream, address block_begin) const {
202 intptr_t offset = (intptr_t)(block_begin - code_begin());
203 _strings.print_block_comment(stream, offset);
204 }
205
206 // Transfer ownership of comments to this CodeBlob
207 void set_strings(CodeStrings& strings) {
208 _strings.assign(strings);
209 }
210
211 static ByteSize name_field_offset() {
212 return byte_offset_of(CodeBlob, _name);
213 }
214
215 static ByteSize oop_maps_field_offset() {
216 return byte_offset_of(CodeBlob, _oop_maps);
217 }
218 };
219
220 class CodeBlobLayout : public StackObj {
221 private:
222 int _size;
223 int _header_size;
224 int _relocation_size;
225 int _content_offset;
226 int _code_offset;
227 int _data_offset;
228 address _code_begin;
229 address _code_end;
230 address _content_begin;
231 address _content_end;
232 address _data_end;
233 address _relocation_begin;
234 address _relocation_end;
235
236 public:
237 CodeBlobLayout(address code_begin, address code_end, address content_begin, address content_end, address data_end, address relocation_begin, address relocation_end) :
238 _size(0),
239 _header_size(0),
240 _relocation_size(0),
241 _content_offset(0),
242 _code_offset(0),
243 _data_offset(0),
244 _content_begin(content_begin),
245 _content_end(content_end),
246 _code_begin(code_begin),
247 _code_end(code_end),
248 _data_end(data_end),
249 _relocation_begin(relocation_begin),
250 _relocation_end(relocation_end)
251 {
252 }
253
254 CodeBlobLayout(const address start, int size, int header_size, int relocation_size, int data_offset) :
255 _size(size),
256 _header_size(header_size),
257 _relocation_size(relocation_size),
258 _content_offset(CodeBlob::align_code_offset(_header_size + _relocation_size)),
259 _code_offset(_content_offset),
260 _data_offset(data_offset)
261 {
262 assert(_relocation_size == round_to(_relocation_size, oopSize), "unaligned size");
263
264 _code_begin = (address) start + _code_offset;
265 _code_end = (address) start + _data_offset;
266
267 _content_begin = (address) start + _content_offset;
268 _content_end = (address) start + _data_offset;
269
270 _data_end = (address) start + _size;
271 _relocation_begin = (address) start + _header_size;
272 _relocation_end = _relocation_begin + _relocation_size;
273 }
274
275 CodeBlobLayout(const address start, int size, int header_size, const CodeBuffer* cb) :
276 _size(size),
277 _header_size(header_size),
278 _relocation_size(round_to(cb->total_relocation_size(), oopSize)),
279 _content_offset(CodeBlob::align_code_offset(_header_size + _relocation_size)),
280 _code_offset(_content_offset + cb->total_offset_of(cb->insts())),
281 _data_offset(_content_offset + round_to(cb->total_content_size(), oopSize))
282 {
283 assert(_relocation_size == round_to(_relocation_size, oopSize), "unaligned size");
284
285 _code_begin = (address) start + _code_offset;
286 _code_end = (address) start + _data_offset;
287
288 _content_begin = (address) start + _content_offset;
289 _content_end = (address) start + _data_offset;
290
291 _data_end = (address) start + _size;
292 _relocation_begin = (address) start + _header_size;
293 _relocation_end = _relocation_begin + _relocation_size;
294 }
295
296 int size() const { return _size; }
297 int header_size() const { return _header_size; }
298 int relocation_size() const { return _relocation_size; }
299 int content_offset() const { return _content_offset; }
300 int code_offset() const { return _code_offset; }
301 int data_offset() const { return _data_offset; }
302 address code_begin() const { return _code_begin; }
303 address code_end() const { return _code_end; }
304 address data_end() const { return _data_end; }
305 address relocation_begin() const { return _relocation_begin; }
306 address relocation_end() const { return _relocation_end; }
307 address content_begin() const { return _content_begin; }
308 address content_end() const { return _content_end; }
309 };
310
311
312 class RuntimeBlob : public CodeBlob {
313 friend class VMStructs;
314 public:
315
316 // Creation
317 // a) simple CodeBlob
318 // frame_complete is the offset from the beginning of the instructions
319 // to where the frame setup (from stackwalk viewpoint) is complete.
320 RuntimeBlob(const char* name, int header_size, int size, int frame_complete, int locs_size);
321
322 // b) full CodeBlob
323 RuntimeBlob(
324 const char* name,
325 CodeBuffer* cb,
326 int header_size,
327 int size,
328 int frame_complete,
329 int frame_size,
330 OopMapSet* oop_maps,
331 bool caller_must_gc_arguments = false
332 );
333
334 // GC support
335 virtual bool is_alive() const = 0;
336
337 void verify();
338
339 // OopMap for frame
340 virtual void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f) { ShouldNotReachHere(); }
341
342 // Debugging
343 void print() const { print_on(tty); }
344 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
345 virtual void print_value_on(outputStream* st) const { CodeBlob::print_value_on(st); }
346
347 // Deal with Disassembler, VTune, Forte, JvmtiExport, MemoryService.
348 static void trace_new_stub(RuntimeBlob* blob, const char* name1, const char* name2 = "");
349 };
350
351 class WhiteBox;
352 //----------------------------------------------------------------------------------------------------
353 // BufferBlob: used to hold non-relocatable machine code such as the interpreter, stubroutines, etc.
354
355 class BufferBlob: public RuntimeBlob {
356 friend class VMStructs;
357 friend class AdapterBlob;
358 friend class MethodHandlesAdapterBlob;
359 friend class WhiteBox;
360
361 private:
362 // Creation support
363 BufferBlob(const char* name, int size);
364 BufferBlob(const char* name, int size, CodeBuffer* cb);
365
366 void* operator new(size_t s, unsigned size) throw();
367
368 public:
369 // Creation
370 static BufferBlob* create(const char* name, int buffer_size);
371 static BufferBlob* create(const char* name, CodeBuffer* cb);
372
373 static void free(BufferBlob* buf);
374
375 // Typing
376 virtual bool is_buffer_blob() const { return true; }
377
378 // GC/Verification support
379 void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f) { /* nothing to do */ }
380 bool is_alive() const { return true; }
381
382 void verify();
383 void print_on(outputStream* st) const;
384 void print_value_on(outputStream* st) const;
385 };
386
387
388 //----------------------------------------------------------------------------------------------------
389 // AdapterBlob: used to hold C2I/I2C adapters
390
391 class AdapterBlob: public BufferBlob {
392 private:
393 AdapterBlob(int size, CodeBuffer* cb);
394
395 public:
396 // Creation
397 static AdapterBlob* create(CodeBuffer* cb);
398
399 // Typing
400 virtual bool is_adapter_blob() const { return true; }
401 };
402
403
404 //----------------------------------------------------------------------------------------------------
405 // MethodHandlesAdapterBlob: used to hold MethodHandles adapters
406
407 class MethodHandlesAdapterBlob: public BufferBlob {
408 private:
409 MethodHandlesAdapterBlob(int size) : BufferBlob("MethodHandles adapters", size) {}
410
411 public:
412 // Creation
413 static MethodHandlesAdapterBlob* create(int buffer_size);
414
415 // Typing
416 virtual bool is_method_handles_adapter_blob() const { return true; }
417 };
418
419
420 //----------------------------------------------------------------------------------------------------
421 // RuntimeStub: describes stubs used by compiled code to call a (static) C++ runtime routine
422
423 class RuntimeStub: public RuntimeBlob {
424 friend class VMStructs;
425 private:
426 // Creation support
427 RuntimeStub(
428 const char* name,
429 CodeBuffer* cb,
430 int size,
431 int frame_complete,
432 int frame_size,
433 OopMapSet* oop_maps,
434 bool caller_must_gc_arguments
435 );
436
437 void* operator new(size_t s, unsigned size) throw();
438
439 public:
440 // Creation
441 static RuntimeStub* new_runtime_stub(
442 const char* stub_name,
443 CodeBuffer* cb,
444 int frame_complete,
445 int frame_size,
446 OopMapSet* oop_maps,
447 bool caller_must_gc_arguments
448 );
449
450 // Typing
451 bool is_runtime_stub() const { return true; }
452
453 address entry_point() const { return code_begin(); }
454
455 // GC/Verification support
456 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) { /* nothing to do */ }
457 bool is_alive() const { return true; }
458
459 void verify();
460 void print_on(outputStream* st) const;
461 void print_value_on(outputStream* st) const;
462 };
463
464
465 //----------------------------------------------------------------------------------------------------
466 // Super-class for all blobs that exist in only one instance. Implements default behaviour.
467
468 class SingletonBlob: public RuntimeBlob {
469 friend class VMStructs;
470
471 protected:
472 void* operator new(size_t s, unsigned size) throw();
473
474 public:
475 SingletonBlob(
476 const char* name,
477 CodeBuffer* cb,
478 int header_size,
479 int size,
480 int frame_size,
481 OopMapSet* oop_maps
482 )
483 : RuntimeBlob(name, cb, header_size, size, CodeOffsets::frame_never_safe, frame_size, oop_maps)
484 {};
485
486 address entry_point() { return code_begin(); }
487
488 bool is_alive() const { return true; }
489
490 // GC/Verification support
491 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) { /* nothing to do */ }
492 void verify(); // does nothing
493 void print_on(outputStream* st) const;
494 void print_value_on(outputStream* st) const;
495 };
496
497
498 //----------------------------------------------------------------------------------------------------
499 // DeoptimizationBlob
500
501 class DeoptimizationBlob: public SingletonBlob {
502 friend class VMStructs;
503 friend class JVMCIVMStructs;
504 private:
505 int _unpack_offset;
506 int _unpack_with_exception;
507 int _unpack_with_reexecution;
508
509 int _unpack_with_exception_in_tls;
510
511 #if INCLUDE_JVMCI
512 // Offsets when JVMCI calls uncommon_trap.
513 int _uncommon_trap_offset;
514 int _implicit_exception_uncommon_trap_offset;
515 #endif
516
517 // Creation support
518 DeoptimizationBlob(
519 CodeBuffer* cb,
520 int size,
521 OopMapSet* oop_maps,
522 int unpack_offset,
523 int unpack_with_exception_offset,
524 int unpack_with_reexecution_offset,
525 int frame_size
526 );
527
528 public:
529 // Creation
530 static DeoptimizationBlob* create(
531 CodeBuffer* cb,
532 OopMapSet* oop_maps,
533 int unpack_offset,
534 int unpack_with_exception_offset,
535 int unpack_with_reexecution_offset,
536 int frame_size
537 );
538
539 // Typing
540 bool is_deoptimization_stub() const { return true; }
541 bool exception_address_is_unpack_entry(address pc) const {
542 address unpack_pc = unpack();
543 return (pc == unpack_pc || (pc + frame::pc_return_offset) == unpack_pc);
544 }
545
546 // GC for args
547 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) { /* Nothing to do */ }
548
549 // Printing
550 void print_value_on(outputStream* st) const;
551
552 address unpack() const { return code_begin() + _unpack_offset; }
553 address unpack_with_exception() const { return code_begin() + _unpack_with_exception; }
554 address unpack_with_reexecution() const { return code_begin() + _unpack_with_reexecution; }
555
556 // Alternate entry point for C1 where the exception and issuing pc
557 // are in JavaThread::_exception_oop and JavaThread::_exception_pc
558 // instead of being in registers. This is needed because C1 doesn't
559 // model exception paths in a way that keeps these registers free so
560 // there may be live values in those registers during deopt.
561 void set_unpack_with_exception_in_tls_offset(int offset) {
562 _unpack_with_exception_in_tls = offset;
563 assert(code_contains(code_begin() + _unpack_with_exception_in_tls), "must be PC inside codeblob");
564 }
565 address unpack_with_exception_in_tls() const { return code_begin() + _unpack_with_exception_in_tls; }
566
567 #if INCLUDE_JVMCI
568 // Offsets when JVMCI calls uncommon_trap.
569 void set_uncommon_trap_offset(int offset) {
570 _uncommon_trap_offset = offset;
571 assert(contains(code_begin() + _uncommon_trap_offset), "must be PC inside codeblob");
572 }
573 address uncommon_trap() const { return code_begin() + _uncommon_trap_offset; }
574
575 void set_implicit_exception_uncommon_trap_offset(int offset) {
576 _implicit_exception_uncommon_trap_offset = offset;
577 assert(contains(code_begin() + _implicit_exception_uncommon_trap_offset), "must be PC inside codeblob");
578 }
579 address implicit_exception_uncommon_trap() const { return code_begin() + _implicit_exception_uncommon_trap_offset; }
580 #endif // INCLUDE_JVMCI
581 };
582
583
584 //----------------------------------------------------------------------------------------------------
585 // UncommonTrapBlob (currently only used by Compiler 2)
586
587 #ifdef COMPILER2
588
589 class UncommonTrapBlob: public SingletonBlob {
590 friend class VMStructs;
591 private:
592 // Creation support
593 UncommonTrapBlob(
594 CodeBuffer* cb,
595 int size,
596 OopMapSet* oop_maps,
597 int frame_size
598 );
599
600 public:
601 // Creation
602 static UncommonTrapBlob* create(
603 CodeBuffer* cb,
604 OopMapSet* oop_maps,
605 int frame_size
606 );
607
608 // GC for args
609 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) { /* nothing to do */ }
610
611 // Typing
612 bool is_uncommon_trap_stub() const { return true; }
613 };
614
615
616 //----------------------------------------------------------------------------------------------------
617 // ExceptionBlob: used for exception unwinding in compiled code (currently only used by Compiler 2)
618
619 class ExceptionBlob: public SingletonBlob {
620 friend class VMStructs;
621 private:
622 // Creation support
623 ExceptionBlob(
624 CodeBuffer* cb,
625 int size,
626 OopMapSet* oop_maps,
627 int frame_size
628 );
629
630 public:
631 // Creation
632 static ExceptionBlob* create(
633 CodeBuffer* cb,
634 OopMapSet* oop_maps,
635 int frame_size
636 );
637
638 // GC for args
639 void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f) { /* nothing to do */ }
640
641 // Typing
642 bool is_exception_stub() const { return true; }
643 };
644 #endif // COMPILER2
645
646
647 //----------------------------------------------------------------------------------------------------
648 // SafepointBlob: handles illegal_instruction exceptions during a safepoint
649
650 class SafepointBlob: public SingletonBlob {
651 friend class VMStructs;
652 private:
653 // Creation support
654 SafepointBlob(
655 CodeBuffer* cb,
656 int size,
657 OopMapSet* oop_maps,
658 int frame_size
659 );
660
661 public:
662 // Creation
663 static SafepointBlob* create(
664 CodeBuffer* cb,
665 OopMapSet* oop_maps,
666 int frame_size
667 );
668
669 // GC for args
670 void preserve_callee_argument_oops(frame fr, const RegisterMap* reg_map, OopClosure* f) { /* nothing to do */ }
671
672 // Typing
673 bool is_safepoint_stub() const { return true; }
674 };
675
676 #endif // SHARE_VM_CODE_CODEBLOB_HPP