Mon, 07 Jul 2014 10:12:40 +0200
8049421: G1 Class Unloading after completing a concurrent mark cycle
Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
Contributed-by: stefan.karlsson@oracle.com, mikael.gerdin@oracle.com
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 */
25 #ifndef SHARE_VM_CODE_NMETHOD_HPP
26 #define SHARE_VM_CODE_NMETHOD_HPP
28 #include "code/codeBlob.hpp"
29 #include "code/pcDesc.hpp"
30 #include "oops/metadata.hpp"
32 // This class is used internally by nmethods, to cache
33 // exception/pc/handler information.
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;
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++; }
52 public:
54 ExceptionCache(Handle exception, address pc, address handler);
56 Klass* exception_type() { return _exception_type; }
57 ExceptionCache* next() { return _next; }
58 void set_next(ExceptionCache *ec) { _next = ec; }
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 };
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 };
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
108 class Dependencies;
109 class ExceptionHandlerTable;
110 class ImplicitExceptionTable;
111 class AbstractCompiler;
112 class xmlStream;
114 class nmethod : public CodeBlob {
115 friend class VMStructs;
116 friend class NMethodSweeper;
117 friend class CodeCache; // scavengable oops
118 private:
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;
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()
129 // To support simple linked-list chaining of nmethods:
130 nmethod* _osr_link; // from InstanceKlass::osr_nmethods_head
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 };
139 static nmethod* volatile _oops_do_mark_nmethods;
140 nmethod* volatile _oops_do_mark_link;
142 AbstractCompiler* _compiler; // The compiler which compiled this nmethod
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
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;
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;
174 // location in frame (offset for sp) that deopt can store the original
175 // pc during a deopt.
176 int _orig_pc_offset;
178 int _compile_id; // which compilation made this nmethod
179 int _comp_level; // compilation level
181 // protected by CodeCache_lock
182 bool _has_flushed_dependencies; // Used for maintenance of dependencies (CodeCache_lock)
184 bool _marked_for_reclamation; // Used by NMethodSweeper (set only by sweeper)
185 bool _marked_for_deoptimization; // Used for stack deoptimization
187 // used by jvmti to track if an unload event has been posted for this nmethod.
188 bool _unload_reported;
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
196 // Protected by Patching_lock
197 volatile unsigned char _state; // {alive, not_entrant, zombie, unloaded}
199 volatile unsigned char _unloading_clock; // Incremented after GC unloaded/cleaned the nmethod
201 #ifdef ASSERT
202 bool _oops_are_stale; // indicates that it's no longer safe to access oops section
203 #endif
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
212 jbyte _scavenge_root_state;
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
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;
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;
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;
240 ExceptionCache *_exception_cache;
241 PcDescCache _pc_desc_cache;
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;
258 friend class nmethodLocker;
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);
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
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);
297 // helper methods
298 void* operator new(size_t size, int nmethod_size) throw();
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();
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);
310 // Inform external interfaces that a compiled method has been unloaded
311 void post_compiled_method_unload();
313 // Initailize fields to their default values
314 void init_defaults();
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);
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);
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);
354 int trap_offset() const { return _trap_offset; }
355 address trap_address() const { return insts_begin() + _trap_offset; }
357 #endif // def HAVE_DTRACE_H
359 // accessors
360 Method* method() const { return _method; }
361 AbstractCompiler* compiler() const { return _compiler; }
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; }
369 bool is_compiled_by_c1() const;
370 bool is_compiled_by_c2() const;
371 bool is_compiled_by_shark() const;
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) ; }
387 Metadata** metadata_begin () const { return (Metadata**) (header_begin() + _metadata_offset) ; }
388 Metadata** metadata_end () const { return (Metadata**) (header_begin() + _scopes_data_offset) ; }
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 ; }
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(); }
413 int total_size () const;
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; }
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(); }
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
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; }
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
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() { return make_not_entrant_or_zombie(not_entrant); }
452 bool make_zombie() { return make_not_entrant_or_zombie(zombie); }
454 // used by jvmti to track if the unload event has been reported
455 bool unload_reported() { return _unload_reported; }
456 void set_unload_reported() { _unload_reported = true; }
458 void set_unloading_next(nmethod* next) { _unloading_next = next; }
459 nmethod* unloading_next() { return _unloading_next; }
461 static unsigned char global_unloading_clock() { return _global_unloading_clock; }
462 static void increase_unloading_clock();
464 void set_unloading_clock(unsigned char unloading_clock);
465 unsigned char unloading_clock();
467 bool is_marked_for_deoptimization() const { return _marked_for_deoptimization; }
468 void mark_for_deoptimization() { _marked_for_deoptimization = true; }
470 void make_unloaded(BoolObjectClosure* is_alive, oop cause);
472 bool has_dependencies() { return dependencies_size() != 0; }
473 void flush_dependencies(BoolObjectClosure* is_alive);
474 bool has_flushed_dependencies() { return _has_flushed_dependencies; }
475 void set_has_flushed_dependencies() {
476 assert(!has_flushed_dependencies(), "should only happen once");
477 _has_flushed_dependencies = 1;
478 }
480 bool is_marked_for_reclamation() const { return _marked_for_reclamation; }
481 void mark_for_reclamation() { _marked_for_reclamation = 1; }
483 bool has_unsafe_access() const { return _has_unsafe_access; }
484 void set_has_unsafe_access(bool z) { _has_unsafe_access = z; }
486 bool has_method_handle_invokes() const { return _has_method_handle_invokes; }
487 void set_has_method_handle_invokes(bool z) { _has_method_handle_invokes = z; }
489 bool is_lazy_critical_native() const { return _lazy_critical_native; }
490 void set_lazy_critical_native(bool z) { _lazy_critical_native = z; }
492 bool has_wide_vectors() const { return _has_wide_vectors; }
493 void set_has_wide_vectors(bool z) { _has_wide_vectors = z; }
495 int comp_level() const { return _comp_level; }
497 // Support for oops in scopes and relocs:
498 // Note: index 0 is reserved for null.
499 oop oop_at(int index) const { return index == 0 ? (oop) NULL: *oop_addr_at(index); }
500 oop* oop_addr_at(int index) const { // for GC
501 // relocation indexes are biased by 1 (because 0 is reserved)
502 assert(index > 0 && index <= oops_size(), "must be a valid non-zero index");
503 assert(!_oops_are_stale, "oops are stale");
504 return &oops_begin()[index - 1];
505 }
507 // Support for meta data in scopes and relocs:
508 // Note: index 0 is reserved for null.
509 Metadata* metadata_at(int index) const { return index == 0 ? NULL: *metadata_addr_at(index); }
510 Metadata** metadata_addr_at(int index) const { // for GC
511 // relocation indexes are biased by 1 (because 0 is reserved)
512 assert(index > 0 && index <= metadata_size(), "must be a valid non-zero index");
513 return &metadata_begin()[index - 1];
514 }
516 void copy_values(GrowableArray<jobject>* oops);
517 void copy_values(GrowableArray<Metadata*>* metadata);
519 // Relocation support
520 private:
521 void fix_oop_relocations(address begin, address end, bool initialize_immediates);
522 inline void initialize_immediate_oop(oop* dest, jobject handle);
524 public:
525 void fix_oop_relocations(address begin, address end) { fix_oop_relocations(begin, end, false); }
526 void fix_oop_relocations() { fix_oop_relocations(NULL, NULL, false); }
527 void verify_oop_relocations();
529 bool is_at_poll_return(address pc);
530 bool is_at_poll_or_poll_return(address pc);
532 // Scavengable oop support
533 bool on_scavenge_root_list() const { return (_scavenge_root_state & 1) != 0; }
534 protected:
535 enum { sl_on_list = 0x01, sl_marked = 0x10 };
536 void set_on_scavenge_root_list() { _scavenge_root_state = sl_on_list; }
537 void clear_on_scavenge_root_list() { _scavenge_root_state = 0; }
538 // assertion-checking and pruning logic uses the bits of _scavenge_root_state
539 #ifndef PRODUCT
540 void set_scavenge_root_marked() { _scavenge_root_state |= sl_marked; }
541 void clear_scavenge_root_marked() { _scavenge_root_state &= ~sl_marked; }
542 bool scavenge_root_not_marked() { return (_scavenge_root_state &~ sl_on_list) == 0; }
543 // N.B. there is no positive marked query, and we only use the not_marked query for asserts.
544 #endif //PRODUCT
545 nmethod* scavenge_root_link() const { return _scavenge_root_link; }
546 void set_scavenge_root_link(nmethod *n) { _scavenge_root_link = n; }
548 public:
550 // Sweeper support
551 long stack_traversal_mark() { return _stack_traversal_mark; }
552 void set_stack_traversal_mark(long l) { _stack_traversal_mark = l; }
554 // Exception cache support
555 ExceptionCache* exception_cache() const { return _exception_cache; }
556 void set_exception_cache(ExceptionCache *ec) { _exception_cache = ec; }
557 address handler_for_exception_and_pc(Handle exception, address pc);
558 void add_handler_for_exception_and_pc(Handle exception, address pc, address handler);
559 void clean_exception_cache(BoolObjectClosure* is_alive);
561 // implicit exceptions support
562 address continuation_for_implicit_exception(address pc);
564 // On-stack replacement support
565 int osr_entry_bci() const { assert(is_osr_method(), "wrong kind of nmethod"); return _entry_bci; }
566 address osr_entry() const { assert(is_osr_method(), "wrong kind of nmethod"); return _osr_entry_point; }
567 void invalidate_osr_method();
568 nmethod* osr_link() const { return _osr_link; }
569 void set_osr_link(nmethod *n) { _osr_link = n; }
571 // tells whether frames described by this nmethod can be deoptimized
572 // note: native wrappers cannot be deoptimized.
573 bool can_be_deoptimized() const { return is_java_method(); }
575 // Inline cache support
576 void clear_inline_caches();
577 void cleanup_inline_caches();
578 bool inlinecache_check_contains(address addr) const {
579 return (addr >= code_begin() && addr < verified_entry_point());
580 }
582 // Verify calls to dead methods have been cleaned.
583 void verify_clean_inline_caches();
584 // Verify and count cached icholder relocations.
585 int verify_icholder_relocations();
586 // Check that all metadata is still alive
587 void verify_metadata_loaders(address low_boundary, BoolObjectClosure* is_alive);
589 // unlink and deallocate this nmethod
590 // Only NMethodSweeper class is expected to use this. NMethodSweeper is not
591 // expected to use any other private methods/data in this class.
593 protected:
594 void flush();
596 public:
597 // When true is returned, it is unsafe to remove this nmethod even if
598 // it is a zombie, since the VM or the ServiceThread might still be
599 // using it.
600 bool is_locked_by_vm() const { return _lock_count >0; }
602 // See comment at definition of _last_seen_on_stack
603 void mark_as_seen_on_stack();
604 bool can_not_entrant_be_converted();
606 // Evolution support. We make old (discarded) compiled methods point to new Method*s.
607 void set_method(Method* method) { _method = method; }
609 // GC support
610 void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred);
611 // The parallel versions are used by G1.
612 bool do_unloading_parallel(BoolObjectClosure* is_alive, bool unloading_occurred);
613 void do_unloading_parallel_postponed(BoolObjectClosure* is_alive, bool unloading_occurred);
614 // Unload a nmethod if the *root object is dead.
615 bool can_unload(BoolObjectClosure* is_alive, oop* root, bool unloading_occurred);
617 void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
618 OopClosure* f);
619 void oops_do(OopClosure* f) { oops_do(f, false); }
620 void oops_do(OopClosure* f, bool allow_zombie);
621 bool detect_scavenge_root_oops();
622 void verify_scavenge_root_oops() PRODUCT_RETURN;
624 bool test_set_oops_do_mark();
625 static void oops_do_marking_prologue();
626 static void oops_do_marking_epilogue();
627 static bool oops_do_marking_is_active() { return _oops_do_mark_nmethods != NULL; }
628 bool test_oops_do_mark() { return _oops_do_mark_link != NULL; }
630 // ScopeDesc for an instruction
631 ScopeDesc* scope_desc_at(address pc);
633 private:
634 ScopeDesc* scope_desc_in(address begin, address end);
636 address* orig_pc_addr(const frame* fr) { return (address*) ((address)fr->unextended_sp() + _orig_pc_offset); }
638 PcDesc* find_pc_desc_internal(address pc, bool approximate);
640 PcDesc* find_pc_desc(address pc, bool approximate) {
641 PcDesc* desc = _pc_desc_cache.last_pc_desc();
642 if (desc != NULL && desc->pc_offset() == pc - code_begin()) {
643 return desc;
644 }
645 return find_pc_desc_internal(pc, approximate);
646 }
648 public:
649 // ScopeDesc retrieval operation
650 PcDesc* pc_desc_at(address pc) { return find_pc_desc(pc, false); }
651 // pc_desc_near returns the first PcDesc at or after the givne pc.
652 PcDesc* pc_desc_near(address pc) { return find_pc_desc(pc, true); }
654 public:
655 // copying of debugging information
656 void copy_scopes_pcs(PcDesc* pcs, int count);
657 void copy_scopes_data(address buffer, int size);
659 // Deopt
660 // Return true is the PC is one would expect if the frame is being deopted.
661 bool is_deopt_pc (address pc) { return is_deopt_entry(pc) || is_deopt_mh_entry(pc); }
662 bool is_deopt_entry (address pc) { return pc == deopt_handler_begin(); }
663 bool is_deopt_mh_entry(address pc) { return pc == deopt_mh_handler_begin(); }
664 // Accessor/mutator for the original pc of a frame before a frame was deopted.
665 address get_original_pc(const frame* fr) { return *orig_pc_addr(fr); }
666 void set_original_pc(const frame* fr, address pc) { *orig_pc_addr(fr) = pc; }
668 static address get_deopt_original_pc(const frame* fr);
670 // MethodHandle
671 bool is_method_handle_return(address return_pc);
673 // jvmti support:
674 void post_compiled_method_load_event();
675 jmethodID get_and_cache_jmethod_id();
677 // verify operations
678 void verify();
679 void verify_scopes();
680 void verify_interrupt_point(address interrupt_point);
682 // printing support
683 void print() const;
684 void print_code();
685 void print_relocations() PRODUCT_RETURN;
686 void print_pcs() PRODUCT_RETURN;
687 void print_scopes() PRODUCT_RETURN;
688 void print_dependencies() PRODUCT_RETURN;
689 void print_value_on(outputStream* st) const PRODUCT_RETURN;
690 void print_calls(outputStream* st) PRODUCT_RETURN;
691 void print_handler_table() PRODUCT_RETURN;
692 void print_nul_chk_table() PRODUCT_RETURN;
693 void print_nmethod(bool print_code);
695 // need to re-define this from CodeBlob else the overload hides it
696 virtual void print_on(outputStream* st) const { CodeBlob::print_on(st); }
697 void print_on(outputStream* st, const char* msg) const;
699 // Logging
700 void log_identity(xmlStream* log) const;
701 void log_new_nmethod() const;
702 void log_state_change() const;
704 // Prints block-level comments, including nmethod specific block labels:
705 virtual void print_block_comment(outputStream* stream, address block_begin) const {
706 print_nmethod_labels(stream, block_begin);
707 CodeBlob::print_block_comment(stream, block_begin);
708 }
709 void print_nmethod_labels(outputStream* stream, address block_begin) const;
711 // Prints a comment for one native instruction (reloc info, pc desc)
712 void print_code_comment_on(outputStream* st, int column, address begin, address end);
713 static void print_statistics() PRODUCT_RETURN;
715 // Compiler task identification. Note that all OSR methods
716 // are numbered in an independent sequence if CICountOSR is true,
717 // and native method wrappers are also numbered independently if
718 // CICountNative is true.
719 int compile_id() const { return _compile_id; }
720 const char* compile_kind() const;
722 // For debugging
723 // CompiledIC* IC_at(char* p) const;
724 // PrimitiveIC* primitiveIC_at(char* p) const;
725 oop embeddedOop_at(address p);
727 // tells if any of this method's dependencies have been invalidated
728 // (this is expensive!)
729 bool check_all_dependencies();
731 // tells if this compiled method is dependent on the given changes,
732 // and the changes have invalidated it
733 bool check_dependency_on(DepChange& changes);
735 // Evolution support. Tells if this compiled method is dependent on any of
736 // methods m() of class dependee, such that if m() in dependee is replaced,
737 // this compiled method will have to be deoptimized.
738 bool is_evol_dependent_on(Klass* dependee);
740 // Fast breakpoint support. Tells if this compiled method is
741 // dependent on the given method. Returns true if this nmethod
742 // corresponds to the given method as well.
743 bool is_dependent_on_method(Method* dependee);
745 // is it ok to patch at address?
746 bool is_patchable_at(address instr_address);
748 // UseBiasedLocking support
749 ByteSize native_receiver_sp_offset() {
750 return _native_receiver_sp_offset;
751 }
752 ByteSize native_basic_lock_sp_offset() {
753 return _native_basic_lock_sp_offset;
754 }
756 // support for code generation
757 static int verified_entry_point_offset() { return offset_of(nmethod, _verified_entry_point); }
758 static int osr_entry_point_offset() { return offset_of(nmethod, _osr_entry_point); }
759 static int entry_bci_offset() { return offset_of(nmethod, _entry_bci); }
761 // RedefineClasses support. Mark metadata in nmethods as on_stack so that
762 // redefine classes doesn't purge it.
763 static void mark_on_stack(nmethod* nm) {
764 nm->metadata_do(Metadata::mark_on_stack);
765 }
766 void metadata_do(void f(Metadata*));
767 };
769 // Locks an nmethod so its code will not get removed and it will not
770 // be made into a zombie, even if it is a not_entrant method. After the
771 // nmethod becomes a zombie, if CompiledMethodUnload event processing
772 // needs to be done, then lock_nmethod() is used directly to keep the
773 // generated code from being reused too early.
774 class nmethodLocker : public StackObj {
775 nmethod* _nm;
777 public:
779 // note: nm can be NULL
780 // Only JvmtiDeferredEvent::compiled_method_unload_event()
781 // should pass zombie_ok == true.
782 static void lock_nmethod(nmethod* nm, bool zombie_ok = false);
783 static void unlock_nmethod(nmethod* nm); // (ditto)
785 nmethodLocker(address pc); // derive nm from pc
786 nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); }
787 nmethodLocker() { _nm = NULL; }
788 ~nmethodLocker() { unlock_nmethod(_nm); }
790 nmethod* code() { return _nm; }
791 void set_code(nmethod* new_nm) {
792 unlock_nmethod(_nm); // note: This works even if _nm==new_nm.
793 _nm = new_nm;
794 lock_nmethod(_nm);
795 }
796 };
798 #endif // SHARE_VM_CODE_NMETHOD_HPP