1 /*
2 * Copyright (c) 1997, 2013, 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_NMETHOD_HPP
26 #define SHARE_VM_CODE_NMETHOD_HPP
27
28 #include "code/codeBlob.hpp"
29 #include "code/pcDesc.hpp"
30 #include "oops/metadata.hpp"
31
32 // This class is used internally by nmethods, to cache
33 // exception/pc/handler information.
34
35 class ExceptionCache : public CHeapObj<mtCode> {
36 friend class VMStructs;
37 private:
38 enum { cache_size = 16 };
39 Klass* _exception_type;
40 address _pc[cache_size];
41 address _handler[cache_size];
42 int _count;
43 ExceptionCache* _next;
44
45 address pc_at(int index) { assert(index >= 0 && index < count(),""); return _pc[index]; }
46 void set_pc_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _pc[index] = a; }
47 address handler_at(int index) { assert(index >= 0 && index < count(),""); return _handler[index]; }
48 void set_handler_at(int index, address a) { assert(index >= 0 && index < cache_size,""); _handler[index] = a; }
49 int count() { return _count; }
50 void increment_count() { _count++; }
51
52 public:
53
54 ExceptionCache(Handle exception, address pc, address handler);
55
56 Klass* exception_type() { return _exception_type; }
57 ExceptionCache* next() { return _next; }
58 void set_next(ExceptionCache *ec) { _next = ec; }
59
60 address match(Handle exception, address pc);
61 bool match_exception_with_space(Handle exception) ;
62 address test_address(address addr);
63 bool add_address_and_handler(address addr, address handler) ;
64 };
65
66
67 // cache pc descs found in earlier inquiries
68 class PcDescCache VALUE_OBJ_CLASS_SPEC {
69 friend class VMStructs;
70 private:
71 enum { cache_size = 4 };
72 PcDesc* _pc_descs[cache_size]; // last cache_size pc_descs found
73 public:
74 PcDescCache() { debug_only(_pc_descs[0] = NULL); }
75 void reset_to(PcDesc* initial_pc_desc);
76 PcDesc* find_pc_desc(int pc_offset, bool approximate);
77 void add_pc_desc(PcDesc* pc_desc);
78 PcDesc* last_pc_desc() { return _pc_descs[0]; }
79 };
80
81
82 // nmethods (native methods) are the compiled code versions of Java methods.
83 //
84 // An nmethod contains:
85 // - header (the nmethod structure)
86 // [Relocation]
87 // - relocation information
88 // - constant part (doubles, longs and floats used in nmethod)
89 // - oop table
90 // [Code]
91 // - code body
92 // - exception handler
93 // - stub code
94 // [Debugging information]
95 // - oop array
96 // - data array
97 // - pcs
98 // [Exception handler table]
99 // - handler entry point array
100 // [Implicit Null Pointer exception table]
101 // - implicit null table array
102
103 class Dependencies;
104 class ExceptionHandlerTable;
105 class ImplicitExceptionTable;
106 class AbstractCompiler;
107 class xmlStream;
108
109 class nmethod : public CodeBlob {
110 friend class VMStructs;
111 friend class NMethodSweeper;
112 friend class CodeCache; // scavengable oops
113 private:
114
115 // GC support to help figure out if an nmethod has been
116 // cleaned/unloaded by the current GC.
117 static unsigned char _global_unloading_clock;
118
119 // Shared fields for all nmethod's
120 Method* _method;
121 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
122 jmethodID _jmethod_id; // Cache of method()->jmethod_id()
123
124 // To support simple linked-list chaining of nmethods:
125 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
126
127 union {
128 // Used by G1 to chain nmethods.
129 nmethod* _unloading_next;
130 // Used by non-G1 GCs to chain nmethods.
131 nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods
132 };
133
134 static nmethod* volatile _oops_do_mark_nmethods;
135 nmethod* volatile _oops_do_mark_link;
136
137 AbstractCompiler* _compiler; // The compiler which compiled this nmethod
138
139 // offsets for entry points
140 address _entry_point; // entry point with class check
141 address _verified_entry_point; // entry point without class check
142 address _osr_entry_point; // entry point for on stack replacement
143
144 // Offsets for different nmethod parts
145 int _exception_offset;
146 // All deoptee's will resume execution at this location described by
147 // this offset.
148 int _deoptimize_offset;
149 // All deoptee's at a MethodHandle call site will resume execution
150 // at this location described by this offset.
151 int _deoptimize_mh_offset;
152 // Offset of the unwind handler if it exists
153 int _unwind_handler_offset;
154
155 #ifdef HAVE_DTRACE_H
156 int _trap_offset;
157 #endif // def HAVE_DTRACE_H
158 int _consts_offset;
159 int _stub_offset;
160 int _oops_offset; // offset to where embedded oop table begins (inside data)
161 int _metadata_offset; // embedded meta data table
162 int _scopes_data_offset;
163 int _scopes_pcs_offset;
164 int _dependencies_offset;
165 int _handler_table_offset;
166 int _nul_chk_table_offset;
167 int _nmethod_end_offset;
168
169 // location in frame (offset for sp) that deopt can store the original
170 // pc during a deopt.
171 int _orig_pc_offset;
172
173 int _compile_id; // which compilation made this nmethod
174 int _comp_level; // compilation level
175
176 // protected by CodeCache_lock
177 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
178
179 bool _marked_for_reclamation; // Used by NMethodSweeper (set only by sweeper)
180 bool _marked_for_deoptimization; // Used for stack deoptimization
181
182 // used by jvmti to track if an unload event has been posted for this nmethod.
183 bool _unload_reported;
184
185 // set during construction
186 unsigned int _has_unsafe_access:1; // May fault due to unsafe access.
187 unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes?
188 unsigned int _lazy_critical_native:1; // Lazy JNI critical native
189 unsigned int _has_wide_vectors:1; // Preserve wide vectors at safepoints
190
191 // Protected by Patching_lock
192 volatile unsigned char _state; // {alive, not_entrant, zombie, unloaded}
193
194 volatile unsigned char _unloading_clock; // Incremented after GC unloaded/cleaned the nmethod
195
196 #ifdef ASSERT
197 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
198 #endif
199
200 enum { in_use = 0, // executable nmethod
201 not_entrant = 1, // marked for deoptimization but activations may still exist,
202 // will be transformed to zombie when all activations are gone
203 zombie = 2, // no activations exist, nmethod is ready for purge
204 unloaded = 3 }; // there should be no activations, should not be called,
205 // will be transformed to zombie immediately
206
207 jbyte _scavenge_root_state;
208
209 #if INCLUDE_RTM_OPT
210 // RTM state at compile time. Used during deoptimization to decide
211 // whether to restart collecting RTM locking abort statistic again.
212 RTMState _rtm_state;
213 #endif
214
215 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed
216 // and is not made into a zombie. However, once the nmethod is made into
217 // a zombie, it will be locked one final time if CompiledMethodUnload
218 // event processing needs to be done.
219 volatile jint _lock_count;
220
221 // not_entrant method removal. Each mark_sweep pass will update
222 // this mark to current sweep invocation count if it is seen on the
223 // stack. An not_entrant method can be removed when there are no
224 // more activations, i.e., when the _stack_traversal_mark is less than
225 // current sweep traversal index.
226 long _stack_traversal_mark;
227
228 // The _hotness_counter indicates the hotness of a method. The higher
229 // the value the hotter the method. The hotness counter of a nmethod is
230 // set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
231 // is active while stack scanning (mark_active_nmethods()). The hotness
232 // counter is decreased (by 1) while sweeping.
233 int _hotness_counter;
234
235 ExceptionCache *_exception_cache;
236 PcDescCache _pc_desc_cache;
237
238 // These are used for compiled synchronized native methods to
239 // locate the owner and stack slot for the BasicLock so that we can
240 // properly revoke the bias of the owner if necessary. They are
241 // needed because there is no debug information for compiled native
242 // wrappers and the oop maps are insufficient to allow
243 // frame::retrieve_receiver() to work. Currently they are expected
244 // to be byte offsets from the Java stack pointer for maximum code
245 // sharing between platforms. Note that currently biased locking
246 // will never cause Class instances to be biased but this code
247 // handles the static synchronized case as well.
248 // JVMTI's GetLocalInstance() also uses these offsets to find the receiver
249 // for non-static native wrapper frames.
250 ByteSize _native_receiver_sp_offset;
251 ByteSize _native_basic_lock_sp_offset;
252
253 friend class nmethodLocker;
254
255 // For native wrappers
256 nmethod(Method* method,
257 int nmethod_size,
258 int compile_id,
259 CodeOffsets* offsets,
260 CodeBuffer *code_buffer,
261 int frame_size,
262 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
263 ByteSize basic_lock_sp_offset, /* synchronized natives only */
264 OopMapSet* oop_maps);
265
266 #ifdef HAVE_DTRACE_H
267 // For native wrappers
268 nmethod(Method* method,
269 int nmethod_size,
270 CodeOffsets* offsets,
271 CodeBuffer *code_buffer,
272 int frame_size);
273 #endif // def HAVE_DTRACE_H
274
275 // Creation support
276 nmethod(Method* method,
277 int nmethod_size,
278 int compile_id,
279 int entry_bci,
280 CodeOffsets* offsets,
281 int orig_pc_offset,
282 DebugInformationRecorder *recorder,
283 Dependencies* dependencies,
284 CodeBuffer *code_buffer,
285 int frame_size,
286 OopMapSet* oop_maps,
287 ExceptionHandlerTable* handler_table,
288 ImplicitExceptionTable* nul_chk_table,
289 AbstractCompiler* compiler,
290 int comp_level);
291
292 // helper methods
293 void* operator new(size_t size, int nmethod_size) throw();
294
295 const char* reloc_string_for(u_char* begin, u_char* end);
296 // Returns true if this thread changed the state of the nmethod or
297 // false if another thread performed the transition.
298 bool make_not_entrant_or_zombie(unsigned int state);
299 void inc_decompile_count();
300
301 // Used to manipulate the exception cache
302 void add_exception_cache_entry(ExceptionCache* new_entry);
303 ExceptionCache* exception_cache_entry_for_exception(Handle exception);
304
305 // Inform external interfaces that a compiled method has been unloaded
306 void post_compiled_method_unload();
307
308 // Initailize fields to their default values
309 void init_defaults();
310
311 public:
312 // create nmethod with entry_bci
313 static nmethod* new_nmethod(methodHandle method,
314 int compile_id,
315 int entry_bci,
316 CodeOffsets* offsets,
317 int orig_pc_offset,
318 DebugInformationRecorder* recorder,
319 Dependencies* dependencies,
320 CodeBuffer *code_buffer,
321 int frame_size,
322 OopMapSet* oop_maps,
323 ExceptionHandlerTable* handler_table,
324 ImplicitExceptionTable* nul_chk_table,
325 AbstractCompiler* compiler,
326 int comp_level);
327
328 static nmethod* new_native_nmethod(methodHandle method,
329 int compile_id,
330 CodeBuffer *code_buffer,
331 int vep_offset,
332 int frame_complete,
333 int frame_size,
334 ByteSize receiver_sp_offset,
335 ByteSize basic_lock_sp_offset,
336 OopMapSet* oop_maps);
337
338 #ifdef HAVE_DTRACE_H
339 // The method we generate for a dtrace probe has to look
340 // like an nmethod as far as the rest of the system is concerned
341 // which is somewhat unfortunate.
342 static nmethod* new_dtrace_nmethod(methodHandle method,
343 CodeBuffer *code_buffer,
344 int vep_offset,
345 int trap_offset,
346 int frame_complete,
347 int frame_size);
348
349 int trap_offset() const { return _trap_offset; }
350 address trap_address() const { return insts_begin() + _trap_offset; }
351
352 #endif // def HAVE_DTRACE_H
353
354 // accessors
355 Method* method() const { return _method; }
356 AbstractCompiler* compiler() const { return _compiler; }
357
358 // type info
359 bool is_nmethod() const { return true; }
360 bool is_java_method() const { return !method()->is_native(); }
361 bool is_native_method() const { return method()->is_native(); }
362 bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
363
364 bool is_compiled_by_c1() const;
365 bool is_compiled_by_c2() const;
366 bool is_compiled_by_shark() const;
367
368 // boundaries for different parts
369 address consts_begin () const { return header_begin() + _consts_offset ; }
370 address consts_end () const { return header_begin() + code_offset() ; }
371 address insts_begin () const { return header_begin() + code_offset() ; }
372 address insts_end () const { return header_begin() + _stub_offset ; }
373 address stub_begin () const { return header_begin() + _stub_offset ; }
374 address stub_end () const { return header_begin() + _oops_offset ; }
375 address exception_begin () const { return header_begin() + _exception_offset ; }
376 address deopt_handler_begin () const { return header_begin() + _deoptimize_offset ; }
377 address deopt_mh_handler_begin() const { return header_begin() + _deoptimize_mh_offset ; }
378 address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; }
379 oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; }
380 oop* oops_end () const { return (oop*) (header_begin() + _metadata_offset) ; }
381
382 Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
383 Metadata** metadata_end () const { return (Metadata**) (header_begin() + _scopes_data_offset) ; }
384
385 address scopes_data_begin () const { return header_begin() + _scopes_data_offset ; }
386 address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
387 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
388 PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; }
389 address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
390 address dependencies_end () const { return header_begin() + _handler_table_offset ; }
391 address handler_table_begin () const { return header_begin() + _handler_table_offset ; }
392 address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
393 address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; }
394 address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
395
396 // Sizes
397 int consts_size () const { return consts_end () - consts_begin (); }
398 int insts_size () const { return insts_end () - insts_begin (); }
399 int stub_size () const { return stub_end () - stub_begin (); }
400 int oops_size () const { return (address) oops_end () - (address) oops_begin (); }
401 int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); }
402 int scopes_data_size () const { return scopes_data_end () - scopes_data_begin (); }
403 int scopes_pcs_size () const { return (intptr_t) scopes_pcs_end () - (intptr_t) scopes_pcs_begin (); }
404 int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
405 int handler_table_size() const { return handler_table_end() - handler_table_begin(); }
406 int nul_chk_table_size() const { return nul_chk_table_end() - nul_chk_table_begin(); }
407
408 int total_size () const;
409
410 void dec_hotness_counter() { _hotness_counter--; }
411 void set_hotness_counter(int val) { _hotness_counter = val; }
412 int hotness_counter() const { return _hotness_counter; }
413
414 // Containment
415 bool consts_contains (address addr) const { return consts_begin () <= addr && addr < consts_end (); }
416 bool insts_contains (address addr) const { return insts_begin () <= addr && addr < insts_end (); }
417 bool stub_contains (address addr) const { return stub_begin () <= addr && addr < stub_end (); }
418 bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
419 bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); }
420 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
421 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
422 bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
423 bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
424
425 // entry points
426 address entry_point() const { return _entry_point; } // normal entry point
427 address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
428
429 // flag accessing and manipulation
430 bool is_in_use() const { return _state == in_use; }
431 bool is_alive() const { return _state == in_use || _state == not_entrant; }
432 bool is_not_entrant() const { return _state == not_entrant; }
433 bool is_zombie() const { return _state == zombie; }
434 bool is_unloaded() const { return _state == unloaded; }
435
436 #if INCLUDE_RTM_OPT
437 // rtm state accessing and manipulating
438 RTMState rtm_state() const { return _rtm_state; }
439 void set_rtm_state(RTMState state) { _rtm_state = state; }
440 #endif
441
442 // Make the nmethod non entrant. The nmethod will continue to be
443 // alive. It is used when an uncommon trap happens. Returns true
444 // if this thread changed the state of the nmethod or false if
445 // another thread performed the transition.
446 bool make_not_entrant() { return make_not_entrant_or_zombie(not_entrant); }
447 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
448
449 // used by jvmti to track if the unload event has been reported
450 bool unload_reported() { return _unload_reported; }
451 void set_unload_reported() { _unload_reported = true; }
452
453 void set_unloading_next(nmethod* next) { _unloading_next = next; }
454 nmethod* unloading_next() { return _unloading_next; }
455
456 static unsigned char global_unloading_clock() { return _global_unloading_clock; }
457 static void increase_unloading_clock();
458
459 void set_unloading_clock(unsigned char unloading_clock);
460 unsigned char unloading_clock();
461
462 bool is_marked_for_deoptimization() const { return _marked_for_deoptimization; }
463 void mark_for_deoptimization() { _marked_for_deoptimization = true; }
464
465 void make_unloaded(BoolObjectClosure* is_alive, oop cause);
466
467 bool has_dependencies() { return dependencies_size() != 0; }
468 void flush_dependencies(BoolObjectClosure* is_alive);
469 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
470 void set_has_flushed_dependencies() {
471 assert(!has_flushed_dependencies(), "should only happen once");
472 _has_flushed_dependencies = 1;
473 }
474
475 bool is_marked_for_reclamation() const { return _marked_for_reclamation; }
476 void mark_for_reclamation() { _marked_for_reclamation = 1; }
477
478 bool has_unsafe_access() const { return _has_unsafe_access; }
479 void set_has_unsafe_access(bool z) { _has_unsafe_access = z; }
480
481 bool has_method_handle_invokes() const { return _has_method_handle_invokes; }
482 void set_has_method_handle_invokes(bool z) { _has_method_handle_invokes = z; }
483
484 bool is_lazy_critical_native() const { return _lazy_critical_native; }
485 void set_lazy_critical_native(bool z) { _lazy_critical_native = z; }
486
487 bool has_wide_vectors() const { return _has_wide_vectors; }
488 void set_has_wide_vectors(bool z) { _has_wide_vectors = z; }
489
490 int comp_level() const { return _comp_level; }
491
492 // Support for oops in scopes and relocs:
493 // Note: index 0 is reserved for null.
494 oop oop_at(int index) const { return index == 0 ? (oop) NULL: *oop_addr_at(index); }
495 oop* oop_addr_at(int index) const { // for GC
496 // relocation indexes are biased by 1 (because 0 is reserved)
497 assert(index > 0 && index <= oops_size(), "must be a valid non-zero index");
498 assert(!_oops_are_stale, "oops are stale");
499 return &oops_begin()[index - 1];
500 }
501
502 // Support for meta data in scopes and relocs:
503 // Note: index 0 is reserved for null.
504 Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
505 Metadata** metadata_addr_at(int index) const { // for GC
506 // relocation indexes are biased by 1 (because 0 is reserved)
507 assert(index > 0 && index <= metadata_size(), "must be a valid non-zero index");
508 return &metadata_begin()[index - 1];
509 }
510
511 void copy_values(GrowableArray<jobject>* oops);
512 void copy_values(GrowableArray<Metadata*>* metadata);
513
514 // Relocation support
515 private:
516 void fix_oop_relocations(address begin, address end, bool initialize_immediates);
517 inline void initialize_immediate_oop(oop* dest, jobject handle);
518
519 public:
520 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
521 void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); }
522 void verify_oop_relocations();
523
524 bool is_at_poll_return(address pc);
525 bool is_at_poll_or_poll_return(address pc);
526
527 // Scavengable oop support
528 bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; }
529 protected:
530 enum { sl_on_list = 0x01, sl_marked = 0x10 };
531 void set_on_scavenge_root_list() { _scavenge_root_state = sl_on_list; }
532 void clear_on_scavenge_root_list() { _scavenge_root_state = 0; }
533 // assertion-checking and pruning logic uses the bits of _scavenge_root_state
534 #ifndef PRODUCT
535 void set_scavenge_root_marked() { _scavenge_root_state |= sl_marked; }
536 void clear_scavenge_root_marked() { _scavenge_root_state &= ~sl_marked; }
537 bool scavenge_root_not_marked() { return (_scavenge_root_state &~ sl_on_list) == 0; }
538 // N.B. there is no positive marked query, and we only use the not_marked query for asserts.
539 #endif //PRODUCT
540 nmethod* scavenge_root_link() const { return _scavenge_root_link; }
541 void set_scavenge_root_link(nmethod *n) { _scavenge_root_link = n; }
542
543 public:
544
545 // Sweeper support
546 long stack_traversal_mark() { return _stack_traversal_mark; }
547 void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
548
549 // Exception cache support
550 ExceptionCache* exception_cache() const { return _exception_cache; }
551 void set_exception_cache(ExceptionCache *ec) { _exception_cache = ec; }
552 address handler_for_exception_and_pc(Handle exception, address pc);
553 void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
554 void clean_exception_cache(BoolObjectClosure* is_alive);
555
556 // implicit exceptions support
557 address continuation_for_implicit_exception(address pc);
558
559 // On-stack replacement support
560 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
561 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
562 void invalidate_osr_method();
563 nmethod* osr_link() const { return _osr_link; }
564 void set_osr_link(nmethod *n) { _osr_link = n; }
565
566 // tells whether frames described by this nmethod can be deoptimized
567 // note: native wrappers cannot be deoptimized.
568 bool can_be_deoptimized() const { return is_java_method(); }
569
570 // Inline cache support
571 void clear_inline_caches();
572 void cleanup_inline_caches();
573 bool inlinecache_check_contains(address addr) const {
574 return (addr >= code_begin() && addr < verified_entry_point());
575 }
576
577 // Verify calls to dead methods have been cleaned.
578 void verify_clean_inline_caches();
579 // Verify and count cached icholder relocations.
580 int verify_icholder_relocations();
581 // Check that all metadata is still alive
582 void verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive);
583
584 // unlink and deallocate this nmethod
585 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
586 // expected to use any other private methods/data in this class.
587
588 protected:
589 void flush();
590
591 public:
592 // When true is returned, it is unsafe to remove this nmethod even if
593 // it is a zombie, since the VM or the ServiceThread might still be
594 // using it.
595 bool is_locked_by_vm() const { return _lock_count >0; }
596
597 // See comment at definition of _last_seen_on_stack
598 void mark_as_seen_on_stack();
599 bool can_not_entrant_be_converted();
600
601 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
602 void set_method(Method* method) { _method = method; }
603
604 // GC support
605 bool stub_contains_dead_metadata(BoolObjectClosure* is_alive, address stub);
606 void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
607 // The parallel versions are used by G1.
608 bool do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred);
609 void do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred);
610 // Unload a nmethod if the *root object is dead.
611 bool can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred);
612
613 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
614 OopClosure* f);
615 void oops_do(OopClosure* f) { oops_do(f, false); }
616 void oops_do(OopClosure* f, bool allow_zombie);
617 bool detect_scavenge_root_oops();
618 void verify_scavenge_root_oops() PRODUCT_RETURN;
619
620 bool test_set_oops_do_mark();
621 static void oops_do_marking_prologue();
622 static void oops_do_marking_epilogue();
623 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
624 bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }
625
626 // ScopeDesc for an instruction
627 ScopeDesc* scope_desc_at(address pc);
628
629 private:
630 ScopeDesc* scope_desc_in(address begin, address end);
631
632 address* orig_pc_addr(const frame* fr) { return (address*) ((address)fr->unextended_sp() + _orig_pc_offset); }
633
634 PcDesc* find_pc_desc_internal(address pc, bool approximate);
635
636 PcDesc* find_pc_desc(address pc, bool approximate) {
637 PcDesc* desc = _pc_desc_cache.last_pc_desc();
638 if (desc != NULL && desc->pc_offset() == pc - code_begin()) {
639 return desc;
640 }
641 return find_pc_desc_internal(pc, approximate);
642 }
643
644 public:
645 // ScopeDesc retrieval operation
646 PcDesc* pc_desc_at(address pc) { return find_pc_desc(pc, false); }
647 // pc_desc_near returns the first PcDesc at or after the givne pc.
648 PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
649
650 public:
651 // copying of debugging information
652 void copy_scopes_pcs(PcDesc* pcs, int count);
653 void copy_scopes_data(address buffer, int size);
654
655 // Deopt
656 // Return true is the PC is one would expect if the frame is being deopted.
657 bool is_deopt_pc (address pc) { return is_deopt_entry(pc) || is_deopt_mh_entry(pc); }
658 bool is_deopt_entry (address pc) { return pc == deopt_handler_begin(); }
659 bool is_deopt_mh_entry(address pc) { return pc == deopt_mh_handler_begin(); }
660 // Accessor/mutator for the original pc of a frame before a frame was deopted.
661 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
662 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
663
664 static address get_deopt_original_pc(const frame* fr);
665
666 // MethodHandle
667 bool is_method_handle_return(address return_pc);
668
669 // jvmti support:
670 void post_compiled_method_load_event();
671 jmethodID get_and_cache_jmethod_id();
672
673 // verify operations
674 void verify();
675 void verify_scopes();
676 void verify_interrupt_point(address interrupt_point);
677
678 // printing support
679 void print() const;
680 void print_code();
681 void print_relocations() PRODUCT_RETURN;
682 void print_pcs() PRODUCT_RETURN;
683 void print_scopes() PRODUCT_RETURN;
684 void print_dependencies() PRODUCT_RETURN;
685 void print_value_on(outputStream* st) const PRODUCT_RETURN;
686 void print_calls(outputStream* st) PRODUCT_RETURN;
687 void print_handler_table() PRODUCT_RETURN;
688 void print_nul_chk_table() PRODUCT_RETURN;
689 void print_nmethod(bool print_code);
690
691 // need to re-define this from CodeBlob else the overload hides it
692 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
693 void print_on(outputStream* st, const char* msg) const;
694
695 // Logging
696 void log_identity(xmlStream* log) const;
697 void log_new_nmethod() const;
698 void log_state_change() const;
699
700 // Prints block-level comments, including nmethod specific block labels:
701 virtual void print_block_comment(outputStream* stream, address block_begin) const {
702 print_nmethod_labels(stream, block_begin);
703 CodeBlob::print_block_comment(stream, block_begin);
704 }
705 void print_nmethod_labels(outputStream* stream, address block_begin) const;
706
707 // Prints a comment for one native instruction (reloc info, pc desc)
708 void print_code_comment_on(outputStream* st, int column, address begin, address end);
709 static void print_statistics() PRODUCT_RETURN;
710
711 // Compiler task identification. Note that all OSR methods
712 // are numbered in an independent sequence if CICountOSR is true,
713 // and native method wrappers are also numbered independently if
714 // CICountNative is true.
715 int compile_id() const { return _compile_id; }
716 const char* compile_kind() const;
717
718 // For debugging
719 // CompiledIC* IC_at(char* p) const;
720 // PrimitiveIC* primitiveIC_at(char* p) const;
721 oop embeddedOop_at(address p);
722
723 // tells if any of this method's dependencies have been invalidated
724 // (this is expensive!)
725 static void check_all_dependencies(DepChange& changes);
726
727 // tells if this compiled method is dependent on the given changes,
728 // and the changes have invalidated it
729 bool check_dependency_on(DepChange& changes);
730
731 // Evolution support. Tells if this compiled method is dependent on any of
732 // methods m() of class dependee, such that if m() in dependee is replaced,
733 // this compiled method will have to be deoptimized.
734 bool is_evol_dependent_on(Klass* dependee);
735
736 // Fast breakpoint support. Tells if this compiled method is
737 // dependent on the given method. Returns true if this nmethod
738 // corresponds to the given method as well.
739 bool is_dependent_on_method(Method* dependee);
740
741 // is it ok to patch at address?
742 bool is_patchable_at(address instr_address);
743
744 // UseBiasedLocking support
745 ByteSize native_receiver_sp_offset() {
746 return _native_receiver_sp_offset;
747 }
748 ByteSize native_basic_lock_sp_offset() {
749 return _native_basic_lock_sp_offset;
750 }
751
752 // support for code generation
753 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
754 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
755 static int entry_bci_offset() { return offset_of(nmethod, _entry_bci); }
756
757 // RedefineClasses support. Mark metadata in nmethods as on_stack so that
758 // redefine classes doesn't purge it.
759 static void mark_on_stack(nmethod* nm) {
760 nm->metadata_do(Metadata::mark_on_stack);
761 }
762 void metadata_do(void f(Metadata*));
763 };
764
765 // Locks an nmethod so its code will not get removed and it will not
766 // be made into a zombie, even if it is a not_entrant method. After the
767 // nmethod becomes a zombie, if CompiledMethodUnload event processing
768 // needs to be done, then lock_nmethod() is used directly to keep the
769 // generated code from being reused too early.
770 class nmethodLocker : public StackObj {
771 nmethod* _nm;
772
773 public:
774
775 // note: nm can be NULL
776 // Only JvmtiDeferredEvent::compiled_method_unload_event()
777 // should pass zombie_ok == true.
778 static void lock_nmethod(nmethod* nm, bool zombie_ok = false);
779 static void unlock_nmethod(nmethod* nm); // (ditto)
780
781 nmethodLocker(address pc); // derive nm from pc
782 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
783 nmethodLocker() { _nm = NULL; }
784 ~nmethodLocker() { unlock_nmethod(_nm); }
785
786 nmethod* code() { return _nm; }
787 void set_code(nmethod* new_nm) {
788 unlock_nmethod(_nm); // note: This works even if _nm==new_nm.
789 _nm = new_nm;
790 lock_nmethod(_nm);
791 }
792 };
793
794 #endif // SHARE_VM_CODE_NMETHOD_HPP