1 #ifdef USE_PRAGMA_IDENT_SRC
2 #pragma ident "@(#)oopMap.cpp 1.153 07/09/28 10:23:20 JVM"
3 #endif
4 /*
5 * Copyright 1998-2007 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 # include "incls/_precompiled.incl"
29 # include "incls/_oopMap.cpp.incl"
30
31 // OopMapStream
32
33 OopMapStream::OopMapStream(OopMap* oop_map) {
34 if(oop_map->omv_data() == NULL) {
35 _stream = new CompressedReadStream(oop_map->write_stream()->buffer());
36 } else {
37 _stream = new CompressedReadStream(oop_map->omv_data());
38 }
39 _mask = OopMapValue::type_mask_in_place;
40 _size = oop_map->omv_count();
41 _position = 0;
42 _valid_omv = false;
43 }
44
45
46 OopMapStream::OopMapStream(OopMap* oop_map, int oop_types_mask) {
47 if(oop_map->omv_data() == NULL) {
48 _stream = new CompressedReadStream(oop_map->write_stream()->buffer());
49 } else {
50 _stream = new CompressedReadStream(oop_map->omv_data());
51 }
52 _mask = oop_types_mask;
53 _size = oop_map->omv_count();
54 _position = 0;
55 _valid_omv = false;
56 }
57
58
59 void OopMapStream::find_next() {
60 while(_position++ < _size) {
61 _omv.read_from(_stream);
62 if(((int)_omv.type() & _mask) > 0) {
63 _valid_omv = true;
64 return;
65 }
66 }
67 _valid_omv = false;
68 }
69
70
71 // OopMap
72
73 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
74 // slots to hold 4-byte values like ints and floats in the LP64 build.
75 OopMap::OopMap(int frame_size, int arg_count) {
76 // OopMaps are usually quite so small, so pick a small initial size
77 set_write_stream(new CompressedWriteStream(32));
78 set_omv_data(NULL);
79 set_omv_count(0);
80
81 #ifdef ASSERT
82 _locs_length = VMRegImpl::stack2reg(0)->value() + frame_size + arg_count;
83 _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
84 for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
85 #endif
86 }
87
88
89 OopMap::OopMap(OopMap::DeepCopyToken, OopMap* source) {
90 // This constructor does a deep copy
91 // of the source OopMap.
92 set_write_stream(new CompressedWriteStream(source->omv_count() * 2));
93 set_omv_data(NULL);
94 set_omv_count(0);
95 set_offset(source->offset());
96
97 #ifdef ASSERT
98 _locs_length = source->_locs_length;
99 _locs_used = NEW_RESOURCE_ARRAY(OopMapValue::oop_types, _locs_length);
100 for(int i = 0; i < _locs_length; i++) _locs_used[i] = OopMapValue::unused_value;
101 #endif
102
103 // We need to copy the entries too.
104 for (OopMapStream oms(source); !oms.is_done(); oms.next()) {
105 OopMapValue omv = oms.current();
106 omv.write_on(write_stream());
107 increment_count();
108 }
109 }
110
111
112 OopMap* OopMap::deep_copy() {
113 return new OopMap(_deep_copy_token, this);
114 }
115
116
117 void OopMap::copy_to(address addr) {
118 memcpy(addr,this,sizeof(OopMap));
119 memcpy(addr + sizeof(OopMap),write_stream()->buffer(),write_stream()->position());
120 OopMap* new_oop = (OopMap*)addr;
121 new_oop->set_omv_data_size(write_stream()->position());
122 new_oop->set_omv_data((unsigned char *)(addr + sizeof(OopMap)));
123 new_oop->set_write_stream(NULL);
124 }
125
126
127 int OopMap::heap_size() const {
128 int size = sizeof(OopMap);
129 int align = sizeof(void *) - 1;
130 if(write_stream() != NULL) {
131 size += write_stream()->position();
132 } else {
133 size += omv_data_size();
134 }
135 // Align to a reasonable ending point
136 size = ((size+align) & ~align);
137 return size;
138 }
139
140 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
141 // slots to hold 4-byte values like ints and floats in the LP64 build.
142 void OopMap::set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional) {
143
144 assert(reg->value() < _locs_length, "too big reg value for stack size");
145 assert( _locs_used[reg->value()] == OopMapValue::unused_value, "cannot insert twice" );
146 debug_only( _locs_used[reg->value()] = x; )
147
148 OopMapValue o(reg, x);
149
150 if(x == OopMapValue::callee_saved_value) {
151 // This can never be a stack location, so we don't need to transform it.
152 assert(optional->is_reg(), "Trying to callee save a stack location");
153 o.set_content_reg(optional);
154 } else if(x == OopMapValue::derived_oop_value) {
155 o.set_content_reg(optional);
156 }
157
158 o.write_on(write_stream());
159 increment_count();
160 }
161
162
163 void OopMap::set_oop(VMReg reg) {
164 set_xxx(reg, OopMapValue::oop_value, VMRegImpl::Bad());
165 }
166
167
168 void OopMap::set_value(VMReg reg) {
169 // At this time, we only need value entries in our OopMap when ZapDeadCompiledLocals is active.
170 if (ZapDeadCompiledLocals)
171 set_xxx(reg, OopMapValue::value_value, VMRegImpl::Bad());
172 }
173
174
175 void OopMap::set_dead(VMReg reg) {
176 // At this time, we only need dead entries in our OopMap when ZapDeadCompiledLocals is active.
177 if (ZapDeadCompiledLocals) {
178 set_xxx(reg, OopMapValue::dead_value, VMRegImpl::Bad());
179 }
180 }
181
182
183 void OopMap::set_callee_saved(VMReg reg, VMReg caller_machine_register ) {
184 set_xxx(reg, OopMapValue::callee_saved_value, caller_machine_register);
185 }
186
187
188 void OopMap::set_derived_oop(VMReg reg, VMReg derived_from_local_register ) {
189 if( reg == derived_from_local_register ) {
190 // Actually an oop, derived shares storage with base,
191 set_oop(reg);
192 } else {
193 set_xxx(reg, OopMapValue::derived_oop_value, derived_from_local_register);
194 }
195 }
196
197 void OopMap::set_stack_obj(VMReg reg) {
198 set_xxx(reg, OopMapValue::stack_obj, VMRegImpl::Bad());
199 }
200
201 // OopMapSet
202
203 OopMapSet::OopMapSet() {
204 set_om_size(MinOopMapAllocation);
205 set_om_count(0);
206 OopMap** temp = NEW_RESOURCE_ARRAY(OopMap*, om_size());
207 set_om_data(temp);
208 }
209
210
211 void OopMapSet::grow_om_data() {
212 int new_size = om_size() * 2;
213 OopMap** new_data = NEW_RESOURCE_ARRAY(OopMap*, new_size);
214 memcpy(new_data,om_data(),om_size() * sizeof(OopMap*));
215 set_om_size(new_size);
216 set_om_data(new_data);
217 }
218
219
220 void OopMapSet::copy_to(address addr) {
221 address temp = addr;
222 int align = sizeof(void *) - 1;
223 // Copy this
224 memcpy(addr,this,sizeof(OopMapSet));
225 temp += sizeof(OopMapSet);
226 temp = (address)((intptr_t)(temp + align) & ~align);
227 // Do the needed fixups to the new OopMapSet
228 OopMapSet* new_set = (OopMapSet*)addr;
229 new_set->set_om_data((OopMap**)temp);
230 // Allow enough space for the OopMap pointers
231 temp += (om_count() * sizeof(OopMap*));
232
233 for(int i=0; i < om_count(); i++) {
234 OopMap* map = at(i);
235 map->copy_to((address)temp);
236 new_set->set(i,(OopMap*)temp);
237 temp += map->heap_size();
238 }
239 // This "locks" the OopMapSet
240 new_set->set_om_size(-1);
241 }
242
243
244 void OopMapSet::add_gc_map(int pc_offset, OopMap *map ) {
245 assert(om_size() != -1,"Cannot grow a fixed OopMapSet");
246
247 if(om_count() >= om_size()) {
248 grow_om_data();
249 }
250 map->set_offset(pc_offset);
251
252 #ifdef ASSERT
253 if(om_count() > 0) {
254 OopMap* last = at(om_count()-1);
255 if (last->offset() == map->offset() ) {
256 fatal("OopMap inserted twice");
257 }
258 if(last->offset() > map->offset()) {
259 tty->print_cr( "WARNING, maps not sorted: pc[%d]=%d, pc[%d]=%d",
260 om_count(),last->offset(),om_count()+1,map->offset());
261 }
262 }
263 #endif // ASSERT
264
265 set(om_count(),map);
266 increment_count();
267 }
268
269
270 int OopMapSet::heap_size() const {
271 // The space we use
272 int size = sizeof(OopMap);
273 int align = sizeof(void *) - 1;
274 size = ((size+align) & ~align);
275 size += om_count() * sizeof(OopMap*);
276
277 // Now add in the space needed for the indivdiual OopMaps
278 for(int i=0; i < om_count(); i++) {
279 size += at(i)->heap_size();
280 }
281 // We don't need to align this, it will be naturally pointer aligned
282 return size;
283 }
284
285
286 OopMap* OopMapSet::singular_oop_map() {
287 guarantee(om_count() == 1, "Make sure we only have a single gc point");
288 return at(0);
289 }
290
291
292 OopMap* OopMapSet::find_map_at_offset(int pc_offset) const {
293 int i, len = om_count();
294 assert( len > 0, "must have pointer maps" );
295
296 // Scan through oopmaps. Stop when current offset is either equal or greater
297 // than the one we are looking for.
298 for( i = 0; i < len; i++) {
299 if( at(i)->offset() >= pc_offset )
300 break;
301 }
302
303 assert( i < len, "oopmap not found" );
304
305 OopMap* m = at(i);
306 assert( m->offset() == pc_offset, "oopmap not found" );
307 return m;
308 }
309
310 class DoNothingClosure: public OopClosure {
311 public: void do_oop(oop* p) {}
312 };
313 static DoNothingClosure do_nothing;
314
315 static void add_derived_oop(oop* base, oop* derived) {
316 #ifndef TIERED
317 COMPILER1_PRESENT(ShouldNotReachHere();)
318 #endif // TIERED
319 #ifdef COMPILER2
320 DerivedPointerTable::add(derived, base);
321 #endif // COMPILER2
322 }
323
324
325 #ifndef PRODUCT
326 static void trace_codeblob_maps(const frame *fr, const RegisterMap *reg_map) {
327 // Print oopmap and regmap
328 tty->print_cr("------ ");
329 CodeBlob* cb = fr->cb();
330 OopMapSet* maps = cb->oop_maps();
331 OopMap* map = cb->oop_map_for_return_address(fr->pc());
332 map->print();
333 if( cb->is_nmethod() ) {
334 nmethod* nm = (nmethod*)cb;
335 // native wrappers have no scope data, it is implied
336 if (nm->is_native_method()) {
337 tty->print("bci: 0 (native)");
338 } else {
339 ScopeDesc* scope = nm->scope_desc_at(fr->pc());
340 tty->print("bci: %d ",scope->bci());
341 }
342 }
343 tty->cr();
344 fr->print_on(tty);
345 tty->print(" ");
346 cb->print_value_on(tty); tty->cr();
347 reg_map->print();
348 tty->print_cr("------ ");
349
350 }
351 #endif // PRODUCT
352
353 void OopMapSet::oops_do(const frame *fr, const RegisterMap* reg_map, OopClosure* f) {
354 // add derived oops to a table
355 all_do(fr, reg_map, f, add_derived_oop, &do_nothing, &do_nothing);
356 }
357
358
359 void OopMapSet::all_do(const frame *fr, const RegisterMap *reg_map,
360 OopClosure* oop_fn, void derived_oop_fn(oop*, oop*),
361 OopClosure* value_fn, OopClosure* dead_fn) {
362 CodeBlob* cb = fr->cb();
363 {
364 assert(cb != NULL, "no codeblob");
365 }
366
367 NOT_PRODUCT(if (TraceCodeBlobStacks) trace_codeblob_maps(fr, reg_map);)
368
369 OopMapSet* maps = cb->oop_maps();
370 OopMap* map = cb->oop_map_for_return_address(fr->pc());
371 assert(map != NULL, " no ptr map found");
372
373 // handle derived pointers first (otherwise base pointer may be
374 // changed before derived pointer offset has been collected)
375 OopMapValue omv;
376 {
377 OopMapStream oms(map,OopMapValue::derived_oop_value);
378 if (!oms.is_done()) {
379 #ifndef TIERED
380 COMPILER1_PRESENT(ShouldNotReachHere();)
381 #endif // !TIERED
382 // Protect the operation on the derived pointers. This
383 // protects the addition of derived pointers to the shared
384 // derived pointer table in DerivedPointerTable::add().
385 MutexLockerEx x(DerivedPointerTableGC_lock, Mutex::_no_safepoint_check_flag);
386 do {
387 omv = oms.current();
388 oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
389 if ( loc != NULL ) {
390 oop *base_loc = fr->oopmapreg_to_location(omv.content_reg(), reg_map);
391 oop *derived_loc = loc;
392 derived_oop_fn(base_loc, derived_loc);
393 }
394 oms.next();
395 } while (!oms.is_done());
396 }
397 }
398
399 // We want dead, value and oop oop_types
400 int mask = OopMapValue::oop_value | OopMapValue::value_value | OopMapValue::dead_value;
401 {
402 for (OopMapStream oms(map,mask); !oms.is_done(); oms.next()) {
403 omv = oms.current();
404 oop* loc = fr->oopmapreg_to_location(omv.reg(),reg_map);
405 if ( loc != NULL ) {
406 if ( omv.type() == OopMapValue::oop_value ) {
407 #ifdef ASSERT
408 if (COMPILER2_PRESENT(!DoEscapeAnalysis &&) !Universe::heap()->is_in_or_null(*loc)) {
409 tty->print_cr("# Found non oop pointer. Dumping state at failure");
410 // try to dump out some helpful debugging information
411 trace_codeblob_maps(fr, reg_map);
412 omv.print();
413 tty->print_cr("loc = %p *loc = %p\n", loc, (address)*loc);
414 // do the real assert.
415 assert(Universe::heap()->is_in_or_null(*loc), "found non oop pointer");
416 }
417 #endif // ASSERT
418 oop_fn->do_oop(loc);
419 } else if ( omv.type() == OopMapValue::value_value ) {
420 value_fn->do_oop(loc);
421 } else if ( omv.type() == OopMapValue::dead_value ) {
422 dead_fn->do_oop(loc);
423 }
424 }
425 }
426 }
427
428 #ifdef COMPILER2
429 if (DoEscapeAnalysis) {
430 for (OopMapStream oms(map, OopMapValue::stack_obj); !oms.is_done(); oms.next()) {
431 omv = oms.current();
432 assert(omv.is_stack_loc(), "should refer to stack location");
433 oop loc = (oop) fr->oopmapreg_to_location(omv.reg(),reg_map);
434 oop_fn->do_oop(&loc);
435 }
436 }
437 #endif // COMPILER2
438 }
439
440
441 // Update callee-saved register info for the following frame
442 void OopMapSet::update_register_map(const frame *fr, RegisterMap *reg_map) {
443 ResourceMark rm;
444 CodeBlob* cb = fr->cb();
445 assert(cb != NULL, "no codeblob");
446
447 // Any reg might be saved by a safepoint handler (see generate_handler_blob).
448 const int max_saved_on_entry_reg_count = ConcreteRegisterImpl::number_of_registers;
449 assert( reg_map->_update_for_id == NULL || fr->is_older(reg_map->_update_for_id),
450 "already updated this map; do not 'update' it twice!" );
451 debug_only(reg_map->_update_for_id = fr->id());
452
453 // Check if caller must update oop argument
454 assert((reg_map->include_argument_oops() ||
455 !cb->caller_must_gc_arguments(reg_map->thread())),
456 "include_argument_oops should already be set");
457
458 int nof_callee = 0;
459 oop* locs[2*max_saved_on_entry_reg_count+1];
460 VMReg regs[2*max_saved_on_entry_reg_count+1];
461 // ("+1" because max_saved_on_entry_reg_count might be zero)
462
463 // Scan through oopmap and find location of all callee-saved registers
464 // (we do not do update in place, since info could be overwritten)
465
466 address pc = fr->pc();
467
468 OopMap* map = cb->oop_map_for_return_address(pc);
469
470 assert(map != NULL, " no ptr map found");
471
472 OopMapValue omv;
473 for(OopMapStream oms(map,OopMapValue::callee_saved_value); !oms.is_done(); oms.next()) {
474 omv = oms.current();
475 assert(nof_callee < 2*max_saved_on_entry_reg_count, "overflow");
476 regs[nof_callee] = omv.content_reg();
477 locs[nof_callee] = fr->oopmapreg_to_location(omv.reg(),reg_map);
478 nof_callee++;
479 }
480
481 // Check that runtime stubs save all callee-saved registers
482 #ifdef COMPILER2
483 assert(cb->is_compiled_by_c1() || !cb->is_runtime_stub() ||
484 (nof_callee >= SAVED_ON_ENTRY_REG_COUNT || nof_callee >= C_SAVED_ON_ENTRY_REG_COUNT),
485 "must save all");
486 #endif // COMPILER2
487
488 // Copy found callee-saved register to reg_map
489 for(int i = 0; i < nof_callee; i++) {
490 reg_map->set_location(regs[i], (address)locs[i]);
491 }
492 }
493
494 //=============================================================================
495 // Non-Product code
496
497 #ifndef PRODUCT
498
499 bool OopMap::has_derived_pointer() const {
500 #ifndef TIERED
501 COMPILER1_PRESENT(return false);
502 #endif // !TIERED
503 #ifdef COMPILER2
504 OopMapStream oms((OopMap*)this,OopMapValue::derived_oop_value);
505 return oms.is_done();
506 #else
507 return false;
508 #endif // COMPILER2
509 }
510
511
512 void print_register_type(OopMapValue::oop_types x, VMReg optional) {
513 switch( x ) {
514 case OopMapValue::oop_value:
515 tty->print("Oop");
516 break;
517 case OopMapValue::value_value:
518 tty->print("Value" );
519 break;
520 case OopMapValue::dead_value:
521 tty->print("Dead" );
522 break;
523 case OopMapValue::callee_saved_value:
524 tty->print("Callers_" );
525 optional->print();
526 break;
527 case OopMapValue::derived_oop_value:
528 tty->print("Derived_oop_" );
529 optional->print();
530 break;
531 case OopMapValue::stack_obj:
532 tty->print("Stack");
533 break;
534 default:
535 ShouldNotReachHere();
536 }
537 }
538
539
540 void OopMapValue::print() const {
541 reg()->print();
542 tty->print("=");
543 print_register_type(type(),content_reg());
544 tty->print(" ");
545 }
546
547
548 void OopMap::print_on(outputStream* st) const {
549 OopMapValue omv;
550 for(OopMapStream oms((OopMap*)this); !oms.is_done(); oms.next()) {
551 omv = oms.current();
552 omv.print_on(st);
553 }
554 }
555
556
557 void OopMapSet::print_on(outputStream* st) const {
558 int i, len = om_count();
559
560 st->print_cr("OopMapSet contains %d OopMaps\n",len);
561
562 for( i = 0; i < len; i++) {
563 OopMap* m = at(i);
564 st->print_cr("OopMap #%d offset:%p",i,m->offset());
565 m->print_on(st);
566 st->print_cr("\n");
567 }
568 }
569 #endif // !PRODUCT
570
571
572 //------------------------------DerivedPointerTable---------------------------
573
574 #ifdef COMPILER2
575
576 class DerivedPointerEntry : public CHeapObj {
577 private:
578 oop* _location; // Location of derived pointer (also pointing to the base)
579 intptr_t _offset; // Offset from base pointer
580 public:
581 DerivedPointerEntry(oop* location, intptr_t offset) { _location = location; _offset = offset; }
582 oop* location() { return _location; }
583 intptr_t offset() { return _offset; }
584 };
585
586
587 GrowableArray<DerivedPointerEntry*>* DerivedPointerTable::_list = NULL;
588 bool DerivedPointerTable::_active = false;
589
590
591 void DerivedPointerTable::clear() {
592 // The first time, we create the list. Otherwise it should be
593 // empty. If not, then we have probably forgotton to call
594 // update_pointers after last GC/Scavenge.
595 assert (!_active, "should not be active");
596 assert(_list == NULL || _list->length() == 0, "table not empty");
597 if (_list == NULL) {
598 _list = new (ResourceObj::C_HEAP) GrowableArray<DerivedPointerEntry*>(10, true); // Allocated on C heap
599 }
600 _active = true;
601 }
602
603
604 // Returns value of location as an int
605 intptr_t value_of_loc(oop *pointer) { return (intptr_t)(*pointer); }
606
607
608 void DerivedPointerTable::add(oop *derived_loc, oop *base_loc) {
609 assert(Universe::heap()->is_in_or_null(*base_loc), "not an oop");
610 assert(derived_loc != base_loc, "Base and derived in same location");
611 if (_active) {
612 assert(*derived_loc != (oop)base_loc, "location already added");
613 assert(_list != NULL, "list must exist");
614 intptr_t offset = value_of_loc(derived_loc) - value_of_loc(base_loc);
615 assert(offset >= -1000000, "wrong derived pointer info");
616
617 if (TraceDerivedPointers) {
618 tty->print_cr(
619 "Add derived pointer@" INTPTR_FORMAT
620 " - Derived: " INTPTR_FORMAT
621 " Base: " INTPTR_FORMAT " (@" INTPTR_FORMAT ") (Offset: %d)",
622 derived_loc, (address)*derived_loc, (address)*base_loc, base_loc, offset
623 );
624 }
625 // Set derived oop location to point to base.
626 *derived_loc = (oop)base_loc;
627 assert_lock_strong(DerivedPointerTableGC_lock);
628 DerivedPointerEntry *entry = new DerivedPointerEntry(derived_loc, offset);
629 _list->append(entry);
630 }
631 }
632
633
634 void DerivedPointerTable::update_pointers() {
635 assert(_list != NULL, "list must exist");
636 for(int i = 0; i < _list->length(); i++) {
637 DerivedPointerEntry* entry = _list->at(i);
638 oop* derived_loc = entry->location();
639 intptr_t offset = entry->offset();
640 // The derived oop was setup to point to location of base
641 oop base = **(oop**)derived_loc;
642 assert(Universe::heap()->is_in_or_null(base), "must be an oop");
643
644 *derived_loc = (oop)(((address)base) + offset);
645 assert(value_of_loc(derived_loc) - value_of_loc(&base) == offset, "sanity check");
646
647 if (TraceDerivedPointers) {
648 tty->print_cr("Updating derived pointer@" INTPTR_FORMAT
649 " - Derived: " INTPTR_FORMAT " Base: " INTPTR_FORMAT " (Offset: %d)",
650 derived_loc, (address)*derived_loc, (address)base, offset);
651 }
652
653 // Delete entry
654 delete entry;
655 _list->at_put(i, NULL);
656 }
657 // Clear list, so it is ready for next traversal (this is an invariant)
658 if (TraceDerivedPointers && !_list->is_empty()) {
659 tty->print_cr("--------------------------");
660 }
661 _list->clear();
662 _active = false;
663 }
664
665 #endif // COMPILER2