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 // The array elements MUST be volatile! Several threads may modify
73 // and read from the cache concurrently. find_pc_desc_internal has
74 // returned wrong results. C++ compiler (namely xlC12) may duplicate
75 // C++ field accesses if the elements are not volatile.
76 typedef PcDesc* PcDescPtr;
77 volatile PcDescPtr _pc_descs[cache_size]; // last cache_size pc_descs found
78 public:
79 PcDescCache() { debug_only(_pc_descs[0] = NULL); }
80 void reset_to(PcDesc* initial_pc_desc);
81 PcDesc* find_pc_desc(int pc_offset, bool approximate);
82 void add_pc_desc(PcDesc* pc_desc);
83 PcDesc* last_pc_desc() { return _pc_descs[0]; }
84 };
85
86
87 // nmethods (native methods) are the compiled code versions of Java methods.
88 //
89 // An nmethod contains:
90 // - header (the nmethod structure)
91 // [Relocation]
92 // - relocation information
93 // - constant part (doubles, longs and floats used in nmethod)
94 // - oop table
95 // [Code]
96 // - code body
97 // - exception handler
98 // - stub code
99 // [Debugging information]
100 // - oop array
101 // - data array
102 // - pcs
103 // [Exception handler table]
104 // - handler entry point array
105 // [Implicit Null Pointer exception table]
106 // - implicit null table array
107
108 class Dependencies;
109 class ExceptionHandlerTable;
110 class ImplicitExceptionTable;
111 class AbstractCompiler;
112 class xmlStream;
113
114 class nmethod : public CodeBlob {
115 friend class VMStructs;
116 friend class NMethodSweeper;
117 friend class CodeCache; // scavengable oops
118 private:
119
120 // GC support to help figure out if an nmethod has been
121 // cleaned/unloaded by the current GC.
122 static unsigned char _global_unloading_clock;
123
124 // Shared fields for all nmethod's
125 Method* _method;
126 int _entry_bci; // != InvocationEntryBci if this nmethod is an on-stack replacement method
127 jmethodID _jmethod_id; // Cache of method()->jmethod_id()
128
129 // To support simple linked-list chaining of nmethods:
130 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
131
132 union {
133 // Used by G1 to chain nmethods.
134 nmethod* _unloading_next;
135 // Used by non-G1 GCs to chain nmethods.
136 nmethod* _scavenge_root_link; // from CodeCache::scavenge_root_nmethods
137 };
138
139 static nmethod* volatile _oops_do_mark_nmethods;
140 nmethod* volatile _oops_do_mark_link;
141
142 AbstractCompiler* _compiler; // The compiler which compiled this nmethod
143
144 // offsets for entry points
145 address _entry_point; // entry point with class check
146 address _verified_entry_point; // entry point without class check
147 address _osr_entry_point; // entry point for on stack replacement
148
149 // Offsets for different nmethod parts
150 int _exception_offset;
151 // All deoptee's will resume execution at this location described by
152 // this offset.
153 int _deoptimize_offset;
154 // All deoptee's at a MethodHandle call site will resume execution
155 // at this location described by this offset.
156 int _deoptimize_mh_offset;
157 // Offset of the unwind handler if it exists
158 int _unwind_handler_offset;
159
160 #ifdef HAVE_DTRACE_H
161 int _trap_offset;
162 #endif // def HAVE_DTRACE_H
163 int _consts_offset;
164 int _stub_offset;
165 int _oops_offset; // offset to where embedded oop table begins (inside data)
166 int _metadata_offset; // embedded meta data table
167 int _scopes_data_offset;
168 int _scopes_pcs_offset;
169 int _dependencies_offset;
170 int _handler_table_offset;
171 int _nul_chk_table_offset;
172 int _nmethod_end_offset;
173
174 // location in frame (offset for sp) that deopt can store the original
175 // pc during a deopt.
176 int _orig_pc_offset;
177
178 int _compile_id; // which compilation made this nmethod
179 int _comp_level; // compilation level
180
181 // protected by CodeCache_lock
182 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
183
184 bool _marked_for_reclamation; // Used by NMethodSweeper (set only by sweeper)
185 bool _marked_for_deoptimization; // Used for stack deoptimization
186
187 // used by jvmti to track if an unload event has been posted for this nmethod.
188 bool _unload_reported;
189
190 // set during construction
191 unsigned int _has_unsafe_access:1; // May fault due to unsafe access.
192 unsigned int _has_method_handle_invokes:1; // Has this method MethodHandle invokes?
193 unsigned int _lazy_critical_native:1; // Lazy JNI critical native
194 unsigned int _has_wide_vectors:1; // Preserve wide vectors at safepoints
195
196 // Protected by Patching_lock
197 volatile unsigned char _state; // {alive, not_entrant, zombie, unloaded}
198
199 volatile unsigned char _unloading_clock; // Incremented after GC unloaded/cleaned the nmethod
200
201 #ifdef ASSERT
202 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
203 #endif
204
205 enum { in_use = 0, // executable nmethod
206 not_entrant = 1, // marked for deoptimization but activations may still exist,
207 // will be transformed to zombie when all activations are gone
208 zombie = 2, // no activations exist, nmethod is ready for purge
209 unloaded = 3 }; // there should be no activations, should not be called,
210 // will be transformed to zombie immediately
211
212 jbyte _scavenge_root_state;
213
214 #if INCLUDE_RTM_OPT
215 // RTM state at compile time. Used during deoptimization to decide
216 // whether to restart collecting RTM locking abort statistic again.
217 RTMState _rtm_state;
218 #endif
219
220 // Nmethod Flushing lock. If non-zero, then the nmethod is not removed
221 // and is not made into a zombie. However, once the nmethod is made into
222 // a zombie, it will be locked one final time if CompiledMethodUnload
223 // event processing needs to be done.
224 jint _lock_count;
225
226 // not_entrant method removal. Each mark_sweep pass will update
227 // this mark to current sweep invocation count if it is seen on the
228 // stack. An not_entrant method can be removed when there are no
229 // more activations, i.e., when the _stack_traversal_mark is less than
230 // current sweep traversal index.
231 long _stack_traversal_mark;
232
233 // The _hotness_counter indicates the hotness of a method. The higher
234 // the value the hotter the method. The hotness counter of a nmethod is
235 // set to [(ReservedCodeCacheSize / (1024 * 1024)) * 2] each time the method
236 // is active while stack scanning (mark_active_nmethods()). The hotness
237 // counter is decreased (by 1) while sweeping.
238 int _hotness_counter;
239
240 ExceptionCache *_exception_cache;
241 PcDescCache _pc_desc_cache;
242
243 // These are used for compiled synchronized native methods to
244 // locate the owner and stack slot for the BasicLock so that we can
245 // properly revoke the bias of the owner if necessary. They are
246 // needed because there is no debug information for compiled native
247 // wrappers and the oop maps are insufficient to allow
248 // frame::retrieve_receiver() to work. Currently they are expected
249 // to be byte offsets from the Java stack pointer for maximum code
250 // sharing between platforms. Note that currently biased locking
251 // will never cause Class instances to be biased but this code
252 // handles the static synchronized case as well.
253 // JVMTI's GetLocalInstance() also uses these offsets to find the receiver
254 // for non-static native wrapper frames.
255 ByteSize _native_receiver_sp_offset;
256 ByteSize _native_basic_lock_sp_offset;
257
258 friend class nmethodLocker;
259
260 // For native wrappers
261 nmethod(Method* method,
262 int nmethod_size,
263 int compile_id,
264 CodeOffsets* offsets,
265 CodeBuffer *code_buffer,
266 int frame_size,
267 ByteSize basic_lock_owner_sp_offset, /* synchronized natives only */
268 ByteSize basic_lock_sp_offset, /* synchronized natives only */
269 OopMapSet* oop_maps);
270
271 #ifdef HAVE_DTRACE_H
272 // For native wrappers
273 nmethod(Method* method,
274 int nmethod_size,
275 CodeOffsets* offsets,
276 CodeBuffer *code_buffer,
277 int frame_size);
278 #endif // def HAVE_DTRACE_H
279
280 // Creation support
281 nmethod(Method* method,
282 int nmethod_size,
283 int compile_id,
284 int entry_bci,
285 CodeOffsets* offsets,
286 int orig_pc_offset,
287 DebugInformationRecorder *recorder,
288 Dependencies* dependencies,
289 CodeBuffer *code_buffer,
290 int frame_size,
291 OopMapSet* oop_maps,
292 ExceptionHandlerTable* handler_table,
293 ImplicitExceptionTable* nul_chk_table,
294 AbstractCompiler* compiler,
295 int comp_level);
296
297 // helper methods
298 void* operator new(size_t size, int nmethod_size) throw();
299
300 const char* reloc_string_for(u_char* begin, u_char* end);
301 // Returns true if this thread changed the state of the nmethod or
302 // false if another thread performed the transition.
303 bool make_not_entrant_or_zombie(unsigned int state);
304 void inc_decompile_count();
305
306 // Used to manipulate the exception cache
307 void add_exception_cache_entry(ExceptionCache* new_entry);
308 ExceptionCache* exception_cache_entry_for_exception(Handle exception);
309
310 // Inform external interfaces that a compiled method has been unloaded
311 void post_compiled_method_unload();
312
313 // Initailize fields to their default values
314 void init_defaults();
315
316 public:
317 // create nmethod with entry_bci
318 static nmethod* new_nmethod(methodHandle method,
319 int compile_id,
320 int entry_bci,
321 CodeOffsets* offsets,
322 int orig_pc_offset,
323 DebugInformationRecorder* recorder,
324 Dependencies* dependencies,
325 CodeBuffer *code_buffer,
326 int frame_size,
327 OopMapSet* oop_maps,
328 ExceptionHandlerTable* handler_table,
329 ImplicitExceptionTable* nul_chk_table,
330 AbstractCompiler* compiler,
331 int comp_level);
332
333 static nmethod* new_native_nmethod(methodHandle method,
334 int compile_id,
335 CodeBuffer *code_buffer,
336 int vep_offset,
337 int frame_complete,
338 int frame_size,
339 ByteSize receiver_sp_offset,
340 ByteSize basic_lock_sp_offset,
341 OopMapSet* oop_maps);
342
343 #ifdef HAVE_DTRACE_H
344 // The method we generate for a dtrace probe has to look
345 // like an nmethod as far as the rest of the system is concerned
346 // which is somewhat unfortunate.
347 static nmethod* new_dtrace_nmethod(methodHandle method,
348 CodeBuffer *code_buffer,
349 int vep_offset,
350 int trap_offset,
351 int frame_complete,
352 int frame_size);
353
354 int trap_offset() const { return _trap_offset; }
355 address trap_address() const { return insts_begin() + _trap_offset; }
356
357 #endif // def HAVE_DTRACE_H
358
359 // accessors
360 Method* method() const { return _method; }
361 AbstractCompiler* compiler() const { return _compiler; }
362
363 // type info
364 bool is_nmethod() const { return true; }
365 bool is_java_method() const { return !method()->is_native(); }
366 bool is_native_method() const { return method()->is_native(); }
367 bool is_osr_method() const { return _entry_bci != InvocationEntryBci; }
368
369 bool is_compiled_by_c1() const;
370 bool is_compiled_by_c2() const;
371 bool is_compiled_by_shark() const;
372
373 // boundaries for different parts
374 address consts_begin () const { return header_begin() + _consts_offset ; }
375 address consts_end () const { return header_begin() + code_offset() ; }
376 address insts_begin () const { return header_begin() + code_offset() ; }
377 address insts_end () const { return header_begin() + _stub_offset ; }
378 address stub_begin () const { return header_begin() + _stub_offset ; }
379 address stub_end () const { return header_begin() + _oops_offset ; }
380 address exception_begin () const { return header_begin() + _exception_offset ; }
381 address deopt_handler_begin () const { return header_begin() + _deoptimize_offset ; }
382 address deopt_mh_handler_begin() const { return header_begin() + _deoptimize_mh_offset ; }
383 address unwind_handler_begin () const { return _unwind_handler_offset != -1 ? (header_begin() + _unwind_handler_offset) : NULL; }
384 oop* oops_begin () const { return (oop*) (header_begin() + _oops_offset) ; }
385 oop* oops_end () const { return (oop*) (header_begin() + _metadata_offset) ; }
386
387 Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
388 Metadata** metadata_end () const { return (Metadata**) (header_begin() + _scopes_data_offset) ; }
389
390 address scopes_data_begin () const { return header_begin() + _scopes_data_offset ; }
391 address scopes_data_end () const { return header_begin() + _scopes_pcs_offset ; }
392 PcDesc* scopes_pcs_begin () const { return (PcDesc*)(header_begin() + _scopes_pcs_offset ); }
393 PcDesc* scopes_pcs_end () const { return (PcDesc*)(header_begin() + _dependencies_offset) ; }
394 address dependencies_begin () const { return header_begin() + _dependencies_offset ; }
395 address dependencies_end () const { return header_begin() + _handler_table_offset ; }
396 address handler_table_begin () const { return header_begin() + _handler_table_offset ; }
397 address handler_table_end () const { return header_begin() + _nul_chk_table_offset ; }
398 address nul_chk_table_begin () const { return header_begin() + _nul_chk_table_offset ; }
399 address nul_chk_table_end () const { return header_begin() + _nmethod_end_offset ; }
400
401 // Sizes
402 int consts_size () const { return consts_end () - consts_begin (); }
403 int insts_size () const { return insts_end () - insts_begin (); }
404 int stub_size () const { return stub_end () - stub_begin (); }
405 int oops_size () const { return (address) oops_end () - (address) oops_begin (); }
406 int metadata_size () const { return (address) metadata_end () - (address) metadata_begin (); }
407 int scopes_data_size () const { return scopes_data_end () - scopes_data_begin (); }
408 int scopes_pcs_size () const { return (intptr_t) scopes_pcs_end () - (intptr_t) scopes_pcs_begin (); }
409 int dependencies_size () const { return dependencies_end () - dependencies_begin (); }
410 int handler_table_size() const { return handler_table_end() - handler_table_begin(); }
411 int nul_chk_table_size() const { return nul_chk_table_end() - nul_chk_table_begin(); }
412
413 int total_size () const;
414
415 void dec_hotness_counter() { _hotness_counter--; }
416 void set_hotness_counter(int val) { _hotness_counter = val; }
417 int hotness_counter() const { return _hotness_counter; }
418
419 // Containment
420 bool consts_contains (address addr) const { return consts_begin () <= addr && addr < consts_end (); }
421 bool insts_contains (address addr) const { return insts_begin () <= addr && addr < insts_end (); }
422 bool stub_contains (address addr) const { return stub_begin () <= addr && addr < stub_end (); }
423 bool oops_contains (oop* addr) const { return oops_begin () <= addr && addr < oops_end (); }
424 bool metadata_contains (Metadata** addr) const { return metadata_begin () <= addr && addr < metadata_end (); }
425 bool scopes_data_contains (address addr) const { return scopes_data_begin () <= addr && addr < scopes_data_end (); }
426 bool scopes_pcs_contains (PcDesc* addr) const { return scopes_pcs_begin () <= addr && addr < scopes_pcs_end (); }
427 bool handler_table_contains(address addr) const { return handler_table_begin() <= addr && addr < handler_table_end(); }
428 bool nul_chk_table_contains(address addr) const { return nul_chk_table_begin() <= addr && addr < nul_chk_table_end(); }
429
430 // entry points
431 address entry_point() const { return _entry_point; } // normal entry point
432 address verified_entry_point() const { return _verified_entry_point; } // if klass is correct
433
434 // flag accessing and manipulation
435 bool is_in_use() const { return _state == in_use; }
436 bool is_alive() const { return _state == in_use || _state == not_entrant; }
437 bool is_not_entrant() const { return _state == not_entrant; }
438 bool is_zombie() const { return _state == zombie; }
439 bool is_unloaded() const { return _state == unloaded; }
440
441 #if INCLUDE_RTM_OPT
442 // rtm state accessing and manipulating
443 RTMState rtm_state() const { return _rtm_state; }
444 void set_rtm_state(RTMState state) { _rtm_state = state; }
445 #endif
446
447 // Make the nmethod non entrant. The nmethod will continue to be
448 // alive. It is used when an uncommon trap happens. Returns true
449 // if this thread changed the state of the nmethod or false if
450 // another thread performed the transition.
451 bool make_not_entrant() {
452 assert(!method()->is_method_handle_intrinsic(), "Cannot make MH intrinsic not entrant");
453 return make_not_entrant_or_zombie(not_entrant);
454 }
455 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
456
457 // used by jvmti to track if the unload event has been reported
458 bool unload_reported() { return _unload_reported; }
459 void set_unload_reported() { _unload_reported = true; }
460
461 void set_unloading_next(nmethod* next) { _unloading_next = next; }
462 nmethod* unloading_next() { return _unloading_next; }
463
464 static unsigned char global_unloading_clock() { return _global_unloading_clock; }
465 static void increase_unloading_clock();
466
467 void set_unloading_clock(unsigned char unloading_clock);
468 unsigned char unloading_clock();
469
470 bool is_marked_for_deoptimization() const { return _marked_for_deoptimization; }
471 void mark_for_deoptimization() { _marked_for_deoptimization = true; }
472
473 void make_unloaded(BoolObjectClosure* is_alive, oop cause);
474
475 bool has_dependencies() { return dependencies_size() != 0; }
476 void flush_dependencies(BoolObjectClosure* is_alive);
477 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
478 void set_has_flushed_dependencies() {
479 assert(!has_flushed_dependencies(), "should only happen once");
480 _has_flushed_dependencies = 1;
481 }
482
483 bool is_marked_for_reclamation() const { return _marked_for_reclamation; }
484 void mark_for_reclamation() { _marked_for_reclamation = 1; }
485
486 bool has_unsafe_access() const { return _has_unsafe_access; }
487 void set_has_unsafe_access(bool z) { _has_unsafe_access = z; }
488
489 bool has_method_handle_invokes() const { return _has_method_handle_invokes; }
490 void set_has_method_handle_invokes(bool z) { _has_method_handle_invokes = z; }
491
492 bool is_lazy_critical_native() const { return _lazy_critical_native; }
493 void set_lazy_critical_native(bool z) { _lazy_critical_native = z; }
494
495 bool has_wide_vectors() const { return _has_wide_vectors; }
496 void set_has_wide_vectors(bool z) { _has_wide_vectors = z; }
497
498 int comp_level() const { return _comp_level; }
499
500 // Support for oops in scopes and relocs:
501 // Note: index 0 is reserved for null.
502 oop oop_at(int index) const { return index == 0 ? (oop) NULL: *oop_addr_at(index); }
503 oop* oop_addr_at(int index) const { // for GC
504 // relocation indexes are biased by 1 (because 0 is reserved)
505 assert(index > 0 && index <= oops_size(), "must be a valid non-zero index");
506 assert(!_oops_are_stale, "oops are stale");
507 return &oops_begin()[index - 1];
508 }
509
510 // Support for meta data in scopes and relocs:
511 // Note: index 0 is reserved for null.
512 Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
513 Metadata** metadata_addr_at(int index) const { // for GC
514 // relocation indexes are biased by 1 (because 0 is reserved)
515 assert(index > 0 && index <= metadata_size(), "must be a valid non-zero index");
516 return &metadata_begin()[index - 1];
517 }
518
519 void copy_values(GrowableArray<jobject>* oops);
520 void copy_values(GrowableArray<Metadata*>* metadata);
521
522 // Relocation support
523 private:
524 void fix_oop_relocations(address begin, address end, bool initialize_immediates);
525 inline void initialize_immediate_oop(oop* dest, jobject handle);
526
527 public:
528 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
529 void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); }
530 void verify_oop_relocations();
531
532 bool is_at_poll_return(address pc);
533 bool is_at_poll_or_poll_return(address pc);
534
535 // Scavengable oop support
536 bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; }
537 protected:
538 enum { sl_on_list = 0x01, sl_marked = 0x10 };
539 void set_on_scavenge_root_list() { _scavenge_root_state = sl_on_list; }
540 void clear_on_scavenge_root_list() { _scavenge_root_state = 0; }
541 // assertion-checking and pruning logic uses the bits of _scavenge_root_state
542 #ifndef PRODUCT
543 void set_scavenge_root_marked() { _scavenge_root_state |= sl_marked; }
544 void clear_scavenge_root_marked() { _scavenge_root_state &= ~sl_marked; }
545 bool scavenge_root_not_marked() { return (_scavenge_root_state &~ sl_on_list) == 0; }
546 // N.B. there is no positive marked query, and we only use the not_marked query for asserts.
547 #endif //PRODUCT
548 nmethod* scavenge_root_link() const { return _scavenge_root_link; }
549 void set_scavenge_root_link(nmethod *n) { _scavenge_root_link = n; }
550
551 public:
552
553 // Sweeper support
554 long stack_traversal_mark() { return _stack_traversal_mark; }
555 void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
556
557 // Exception cache support
558 ExceptionCache* exception_cache() const { return _exception_cache; }
559 void set_exception_cache(ExceptionCache *ec) { _exception_cache = ec; }
560 address handler_for_exception_and_pc(Handle exception, address pc);
561 void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
562 void clean_exception_cache(BoolObjectClosure* is_alive);
563
564 // implicit exceptions support
565 address continuation_for_implicit_exception(address pc);
566
567 // On-stack replacement support
568 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
569 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
570 void invalidate_osr_method();
571 nmethod* osr_link() const { return _osr_link; }
572 void set_osr_link(nmethod *n) { _osr_link = n; }
573
574 // tells whether frames described by this nmethod can be deoptimized
575 // note: native wrappers cannot be deoptimized.
576 bool can_be_deoptimized() const { return is_java_method(); }
577
578 // Inline cache support
579 void clear_inline_caches();
580 void cleanup_inline_caches();
581 bool inlinecache_check_contains(address addr) const {
582 return (addr >= code_begin() && addr < verified_entry_point());
583 }
584
585 // Verify calls to dead methods have been cleaned.
586 void verify_clean_inline_caches();
587 // Verify and count cached icholder relocations.
588 int verify_icholder_relocations();
589 // Check that all metadata is still alive
590 void verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive);
591
592 // unlink and deallocate this nmethod
593 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
594 // expected to use any other private methods/data in this class.
595
596 protected:
597 void flush();
598
599 public:
600 // When true is returned, it is unsafe to remove this nmethod even if
601 // it is a zombie, since the VM or the ServiceThread might still be
602 // using it.
603 bool is_locked_by_vm() const { return _lock_count >0; }
604
605 // See comment at definition of _last_seen_on_stack
606 void mark_as_seen_on_stack();
607 bool can_not_entrant_be_converted();
608
609 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
610 void set_method(Method* method) { _method = method; }
611
612 // GC support
613 void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
614 // The parallel versions are used by G1.
615 bool do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred);
616 void do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred);
617
618 private:
619 // Unload a nmethod if the *root object is dead.
620 bool can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred);
621 bool unload_if_dead_at(RelocIterator *iter_at_oop, BoolObjectClosure* is_alive, bool unloading_occurred);
622
623 void mark_metadata_on_stack_at(RelocIterator* iter_at_metadata);
624 void mark_metadata_on_stack_non_relocs();
625
626 public:
627 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
628 OopClosure* f);
629 void oops_do(OopClosure* f) { oops_do(f, false); }
630 void oops_do(OopClosure* f, bool allow_zombie);
631 bool detect_scavenge_root_oops();
632 void verify_scavenge_root_oops() PRODUCT_RETURN;
633
634 bool test_set_oops_do_mark();
635 static void oops_do_marking_prologue();
636 static void oops_do_marking_epilogue();
637 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
638 bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }
639
640 // ScopeDesc for an instruction
641 ScopeDesc* scope_desc_at(address pc);
642
643 private:
644 ScopeDesc* scope_desc_in(address begin, address end);
645
646 address* orig_pc_addr(const frame* fr) { return (address*) ((address)fr->unextended_sp() + _orig_pc_offset); }
647
648 PcDesc* find_pc_desc_internal(address pc, bool approximate);
649
650 PcDesc* find_pc_desc(address pc, bool approximate) {
651 PcDesc* desc = _pc_desc_cache.last_pc_desc();
652 if (desc != NULL && desc->pc_offset() == pc - code_begin()) {
653 return desc;
654 }
655 return find_pc_desc_internal(pc, approximate);
656 }
657
658 public:
659 // ScopeDesc retrieval operation
660 PcDesc* pc_desc_at(address pc) { return find_pc_desc(pc, false); }
661 // pc_desc_near returns the first PcDesc at or after the givne pc.
662 PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
663
664 public:
665 // copying of debugging information
666 void copy_scopes_pcs(PcDesc* pcs, int count);
667 void copy_scopes_data(address buffer, int size);
668
669 // Deopt
670 // Return true is the PC is one would expect if the frame is being deopted.
671 bool is_deopt_pc (address pc) { return is_deopt_entry(pc) || is_deopt_mh_entry(pc); }
672 bool is_deopt_entry (address pc) { return pc == deopt_handler_begin(); }
673 bool is_deopt_mh_entry(address pc) { return pc == deopt_mh_handler_begin(); }
674 // Accessor/mutator for the original pc of a frame before a frame was deopted.
675 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
676 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
677
678 static address get_deopt_original_pc(const frame* fr);
679
680 // MethodHandle
681 bool is_method_handle_return(address return_pc);
682
683 // jvmti support:
684 void post_compiled_method_load_event();
685 jmethodID get_and_cache_jmethod_id();
686
687 // verify operations
688 void verify();
689 void verify_scopes();
690 void verify_interrupt_point(address interrupt_point);
691
692 // printing support
693 void print() const;
694 void print_code();
695 void print_relocations() PRODUCT_RETURN;
696 void print_pcs() PRODUCT_RETURN;
697 void print_scopes() PRODUCT_RETURN;
698 void print_dependencies() PRODUCT_RETURN;
699 void print_value_on(outputStream* st) const PRODUCT_RETURN;
700 void print_calls(outputStream* st) PRODUCT_RETURN;
701 void print_handler_table() PRODUCT_RETURN;
702 void print_nul_chk_table() PRODUCT_RETURN;
703 void print_nmethod(bool print_code);
704
705 // need to re-define this from CodeBlob else the overload hides it
706 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
707 void print_on(outputStream* st, const char* msg) const;
708
709 // Logging
710 void log_identity(xmlStream* log) const;
711 void log_new_nmethod() const;
712 void log_state_change() const;
713
714 // Prints block-level comments, including nmethod specific block labels:
715 virtual void print_block_comment(outputStream* stream, address block_begin) const {
716 print_nmethod_labels(stream, block_begin);
717 CodeBlob::print_block_comment(stream, block_begin);
718 }
719 void print_nmethod_labels(outputStream* stream, address block_begin) const;
720
721 // Prints a comment for one native instruction (reloc info, pc desc)
722 void print_code_comment_on(outputStream* st, int column, address begin, address end);
723 static void print_statistics() PRODUCT_RETURN;
724
725 // Compiler task identification. Note that all OSR methods
726 // are numbered in an independent sequence if CICountOSR is true,
727 // and native method wrappers are also numbered independently if
728 // CICountNative is true.
729 int compile_id() const { return _compile_id; }
730 const char* compile_kind() const;
731
732 // For debugging
733 // CompiledIC* IC_at(char* p) const;
734 // PrimitiveIC* primitiveIC_at(char* p) const;
735 oop embeddedOop_at(address p);
736
737 // tells if any of this method's dependencies have been invalidated
738 // (this is expensive!)
739 bool check_all_dependencies();
740
741 // tells if this compiled method is dependent on the given changes,
742 // and the changes have invalidated it
743 bool check_dependency_on(DepChange& changes);
744
745 // Evolution support. Tells if this compiled method is dependent on any of
746 // methods m() of class dependee, such that if m() in dependee is replaced,
747 // this compiled method will have to be deoptimized.
748 bool is_evol_dependent_on(Klass* dependee);
749
750 // Fast breakpoint support. Tells if this compiled method is
751 // dependent on the given method. Returns true if this nmethod
752 // corresponds to the given method as well.
753 bool is_dependent_on_method(Method* dependee);
754
755 // is it ok to patch at address?
756 bool is_patchable_at(address instr_address);
757
758 // UseBiasedLocking support
759 ByteSize native_receiver_sp_offset() {
760 return _native_receiver_sp_offset;
761 }
762 ByteSize native_basic_lock_sp_offset() {
763 return _native_basic_lock_sp_offset;
764 }
765
766 // support for code generation
767 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
768 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
769 static int entry_bci_offset() { return offset_of(nmethod, _entry_bci); }
770
771 // RedefineClasses support. Mark metadata in nmethods as on_stack so that
772 // redefine classes doesn't purge it.
773 static void mark_on_stack(nmethod* nm) {
774 nm->metadata_do(Metadata::mark_on_stack);
775 }
776 void metadata_do(void f(Metadata*));
777 };
778
779 // Locks an nmethod so its code will not get removed and it will not
780 // be made into a zombie, even if it is a not_entrant method. After the
781 // nmethod becomes a zombie, if CompiledMethodUnload event processing
782 // needs to be done, then lock_nmethod() is used directly to keep the
783 // generated code from being reused too early.
784 class nmethodLocker : public StackObj {
785 nmethod* _nm;
786
787 public:
788
789 // note: nm can be NULL
790 // Only JvmtiDeferredEvent::compiled_method_unload_event()
791 // should pass zombie_ok == true.
792 static void lock_nmethod(nmethod* nm, bool zombie_ok = false);
793 static void unlock_nmethod(nmethod* nm); // (ditto)
794
795 nmethodLocker(address pc); // derive nm from pc
796 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
797 nmethodLocker() { _nm = NULL; }
798 ~nmethodLocker() { unlock_nmethod(_nm); }
799
800 nmethod* code() { return _nm; }
801 void set_code(nmethod* new_nm) {
802 unlock_nmethod(_nm); // note: This works even if _nm==new_nm.
803 _nm = new_nm;
804 lock_nmethod(_nm);
805 }
806 };
807
808 #endif // SHARE_VM_CODE_NMETHOD_HPP