1 /*
2 * Copyright (c) 2016, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "gc/shared/gcLocker.hpp"
27 #include "memory/vtBuffer.hpp"
28 #include "oops/oop.inline.hpp"
29 #include "oops/valueKlass.hpp"
30 #include "runtime/frame.hpp"
31 #include "runtime/thread.hpp"
32 #include "utilities/globalDefinitions.hpp"
33 #include "utilities/ticks.hpp"
34 #include "utilities/ticks.inline.hpp"
35 #if INCLUDE_ALL_GCS
36 #include "gc/g1/g1SATBCardTableModRefBS.hpp"
37 #endif // INCLUDE_ALL_GCS
38
39
40 VTBufferChunk* VTBuffer::_free_list = NULL;
41 Mutex* VTBuffer::_pool_lock = new Mutex(Mutex::leaf, "VTBuffer::_pool_lock", true, Monitor::_safepoint_check_never);
42 int VTBuffer::_pool_counter = 0;
43 int VTBuffer::_max_pool_counter = 0;
44 int VTBuffer::_total_allocated = 0;
45 int VTBuffer::_total_deallocated = 0;
46 int VTBuffer::_total_failed = 0;
47
48 void VTBufferChunk::zap(void* start) {
49 assert(this == (VTBufferChunk*)((intptr_t)start & chunk_mask()), "start must be in current chunk");
50 if (ZapVTBufferChunks) {
51 size_t size = chunk_size() - ((char*)start - (char*)this);
52 memset((char*)start, 0, size);
53 }
54 }
55
56 oop VTBuffer::allocate_value(ValueKlass* k, TRAPS) {
57 assert(THREAD->is_Java_thread(), "Only JavaThreads have a buffer for value types");
58 JavaThread* thread = (JavaThread*)THREAD;
59 if (thread->vt_alloc_ptr() == NULL) {
60 if (!allocate_vt_chunk(thread)) {
61 return NULL; // will trigger fall back strategy: allocation in Java heap
62 }
63 }
64 assert(thread->vt_alloc_ptr() != NULL, "should not be null if chunk allocation was successful");
65 int allocation_size_in_bytes = k->size_helper() * HeapWordSize;
66 if ((char*)thread->vt_alloc_ptr() + allocation_size_in_bytes >= thread->vt_alloc_limit()) {
67 if (allocation_size_in_bytes > (int)VTBufferChunk::max_alloc_size()) {
68 // Too big to be allocated in a buffer
69 return NULL;
70 }
71 VTBufferChunk* next = VTBufferChunk::chunk(thread->vt_alloc_ptr())->next();
72 if (next != NULL) {
73 thread->set_vt_alloc_ptr(next->first_alloc());
74 thread->set_vt_alloc_limit(next->alloc_limit());
75 } else {
76 if (!allocate_vt_chunk(thread)) {
77 return NULL; // will trigger fall back strategy: allocation in Java heap
78 }
79 }
80 }
81 assert((char*)thread->vt_alloc_ptr() + allocation_size_in_bytes < thread->vt_alloc_limit(),"otherwise the logic above is wrong");
82 oop new_vt = (oop)thread->vt_alloc_ptr();
83 int allocation_size_in_words = k->size_helper();
84 thread->increment_vtchunk_total_memory_buffered(allocation_size_in_words * HeapWordSize);
85 int increment = align_object_size(allocation_size_in_words);
86 void* new_ptr = (char*)thread->vt_alloc_ptr() + increment * HeapWordSize;
87 new_ptr = MIN2(new_ptr, thread->vt_alloc_limit());
88 assert(VTBufferChunk::chunk(new_ptr) == VTBufferChunk::chunk(thread->vt_alloc_ptr()),
89 "old and new alloc ptr must be in the same chunk");
90 thread->set_vt_alloc_ptr(new_ptr);
91 // the value and its header must be initialized before being returned!!!
92 memset(((char*)(oopDesc*)new_vt), 0, allocation_size_in_bytes);
93 new_vt->set_klass(k);
94 assert(((intptr_t)(oopDesc*)k->java_mirror() & (intptr_t)VTBuffer::mark_mask) == 0, "Checking least significant bits are available");
95 new_vt->set_mark(markOop(k->java_mirror()));
96 if (UseG1GC) {
97 G1SATBCardTableModRefBS::enqueue(k->java_mirror());
98 }
99 return new_vt;
100 }
101
102 bool VTBuffer::allocate_vt_chunk(JavaThread* thread) {
103 VTBufferChunk* new_chunk = NULL;
104 // Trying local cache;
105 if (thread->local_free_chunk() != NULL) {
106 new_chunk = thread->local_free_chunk();
107 thread->set_local_free_chunk(NULL);
108 } else {
109 // Trying global pool
110 MutexLockerEx ml(_pool_lock, Mutex::_no_safepoint_check_flag);
111 if (_free_list != NULL) {
112 new_chunk = _free_list;
113 _free_list = new_chunk->next();
114 if (_free_list != NULL) {
115 _free_list->set_prev(NULL);
116 }
117 new_chunk->set_next(NULL);
118 _pool_counter--;
119 } else {
120 // A new chunk has to be allocated
121 // Hold _pool_lock to maintain counters
122 if ((_total_allocated + 1) <= ValueTypesBufferMaxMemory) {
123 // Allocate new chunk only if total size for buffer
124 // memory is below its max size
125 new_chunk = new VTBufferChunk(thread);
126 _total_allocated += new_chunk == NULL ? 0 : 1;
127 }
128 }
129 }
130 if (new_chunk == NULL) {
131 _total_failed++;
132 thread->increment_vtchunk_failed();
133 return false; // allocation failed
134 }
135 VTBufferChunk* current = thread->current_chunk();
136 assert(new_chunk->owner() == thread || new_chunk->owner()== NULL, "Sanity check");
137 assert(new_chunk->index() == -1, "Sanity check");
138 new_chunk->set_owner(thread);
139 if(current != NULL) {
140 new_chunk->set_prev(current);
141 new_chunk->set_index(current->index() + 1);
142 current->set_next(new_chunk);
143 } else {
144 new_chunk->set_index(0);
145 }
146 thread->increment_vtchunk_in_use();
147 thread->set_vt_alloc_ptr(new_chunk->first_alloc());
148 thread->set_vt_alloc_limit(new_chunk->alloc_limit());
149 return true; // allocation was successful
150 }
151
152 void VTBuffer::recycle_chunk(JavaThread* thread, VTBufferChunk* chunk) {
153 if (thread->local_free_chunk() == NULL) {
154 chunk->set_prev(NULL);
155 chunk->set_next(NULL);
156 chunk->set_index(-1);
157 chunk->zap(chunk->first_alloc());
158 thread->set_local_free_chunk(chunk);
159 } else {
160 return_vt_chunk(thread, chunk);
161 }
162 thread->decrement_vtchunk_in_use();
163 }
164
165 // This is the main way to recycle VTBuffer memory, it is called from
166 // remove_activation() when an interpreter frame is about to be removed
167 // from the stack. All memory used in the context of this frame is freed,
168 // and the vt_alloc_ptr is restored to the value it had when the frame
169 // was created (modulo a possible adjustment if a value is being returned)
170 void VTBuffer::recycle_vtbuffer(JavaThread* thread, void* alloc_ptr) {
171 address current_ptr = (address)thread->vt_alloc_ptr();
172 assert(current_ptr != NULL, "Should not reach here if NULL");
173 VTBufferChunk* current_chunk = VTBufferChunk::chunk(current_ptr);
174 assert(current_chunk->owner() == thread, "Sanity check");
175 address previous_ptr = (address)alloc_ptr;
176 if (previous_ptr == NULL) {
177 // vt_alloc_ptr has not been initialized in this frame
178 // let's initialize it to the first_alloc() value of the first chunk
179 VTBufferChunk* first_chunk = current_chunk;
180 while (first_chunk->prev() != NULL) {
181 first_chunk = first_chunk->prev();
182 }
183 previous_ptr = (address)first_chunk->first_alloc();
184 }
185 assert(previous_ptr != NULL, "Should not reach here if NULL");
186 VTBufferChunk* previous_chunk = VTBufferChunk::chunk(previous_ptr);
187 assert(previous_chunk->owner() == thread, "Sanity check");
188 if (current_ptr == previous_ptr) return;
189 assert(current_chunk != previous_chunk || current_ptr >= previous_ptr, "Sanity check");
190 VTBufferChunk* del = previous_chunk->next();
191 previous_chunk->set_next(NULL);
192 thread->set_vt_alloc_ptr(previous_ptr);
193 previous_chunk->zap(previous_ptr);
194 thread->set_vt_alloc_limit(previous_chunk->alloc_limit());
195 while (del != NULL) {
196 VTBufferChunk* temp = del->next();
197 VTBuffer::recycle_chunk(thread, del);
198 del = temp;
199 }
200 }
201
202 void VTBuffer::return_vt_chunk(JavaThread* thread, VTBufferChunk* chunk) {
203 chunk->set_prev(NULL);
204 chunk->set_owner(NULL);
205 chunk->set_index(-1);
206 chunk->zap(chunk->first_alloc());
207 MutexLockerEx ml(_pool_lock, Mutex::_no_safepoint_check_flag);
208 if (_pool_counter < _max_free_list) {
209 if (_free_list != NULL) {
210 chunk->set_next(_free_list);
211 _free_list->set_prev(chunk);
212 _free_list = chunk;
213 } else {
214 chunk->set_next(NULL);
215 _free_list = chunk;
216 }
217 _pool_counter++;
218 if (_pool_counter > _max_pool_counter) {
219 _max_pool_counter = _pool_counter;
220 }
221 } else {
222 delete chunk;
223 _total_deallocated++;
224 }
225 thread->increment_vtchunk_returned();
226 }
227
228 bool VTBuffer::value_belongs_to_frame(oop p, frame* f) {
229 return is_value_allocated_after(p, f->interpreter_frame_vt_alloc_ptr());
230 }
231
232 bool VTBuffer::is_value_allocated_after(oop p, void* a) {
233 // Test if value p has been allocated after alloc ptr a
234 int p_chunk_idx = VTBufferChunk::chunk(p)->index();
235 int frame_first_chunk_idx;
236 if (a != NULL) {
237 frame_first_chunk_idx = VTBufferChunk::chunk(a)->index();
238 } else {
239 frame_first_chunk_idx = 0;
240 }
241 if (p_chunk_idx == frame_first_chunk_idx) {
242 return (intptr_t*)p >= a;
243 } else {
244 return p_chunk_idx > frame_first_chunk_idx;
245 }
246 }
247
248 void VTBuffer::fix_frame_vt_alloc_ptr(frame f, VTBufferChunk* chunk) {
249 assert(f.is_interpreted_frame(), "recycling can only be triggered from interpreted frames");
250 assert(chunk != NULL, "Should not be called if null");
251 while (chunk->prev() != NULL) {
252 chunk = chunk->prev();
253 }
254 f.interpreter_frame_set_vt_alloc_ptr((intptr_t*)chunk->first_alloc());
255 }
256
257 extern "C" {
258 static int compare_reloc_entries(const void* void_a, const void* void_b) {
259 struct VT_relocation_entry* entry_a = (struct VT_relocation_entry*)void_a;
260 struct VT_relocation_entry* entry_b = (struct VT_relocation_entry*)void_b;
261 if (entry_a->chunk_index == entry_b->chunk_index) {
262 if (entry_a->old_ptr < entry_b->old_ptr) {
263 return -1;
264 } else {
265 return 1;
266 }
267 } else {
268 if (entry_a->chunk_index < entry_b->chunk_index) {
269 return -1;
270 } else {
271 return 1;
272 }
273 }
274 }
275 }
276
277 void dump_reloc_table(struct VT_relocation_entry* table, int nelem, bool print_new_ptr) {
278 ResourceMark rm;
279 for (int i = 0; i < nelem; i++) {
280 InstanceKlass* ik = InstanceKlass::cast(((oop)table[i].old_ptr)->klass());
281 tty->print("%d:\t%p\t%d\t%s\t%x", i, table[i].old_ptr, table[i].chunk_index,
282 ik->name()->as_C_string(), ik->size_helper() * HeapWordSize);
283 if (print_new_ptr) {
284 tty->print_cr("\t%p\t%d\n", table[i].new_ptr, VTBufferChunk::chunk(table[i].new_ptr)->index());
285 } else {
286 tty->print_cr("");
287 }
288 }
289 }
290
291 // Relocate value 'old' after value 'previous'
292 address VTBuffer::relocate_value(address old, address previous, int previous_size_in_words) {
293 InstanceKlass* ik_old = InstanceKlass::cast(((oop)old)->klass());
294 assert(ik_old->is_value(), "Sanity check");
295 VTBufferChunk* chunk = VTBufferChunk::chunk(previous);
296 address next_alloc = previous + previous_size_in_words * HeapWordSize;
297 if(next_alloc + ik_old->size_helper() * HeapWordSize < chunk->alloc_limit()) {
298 // relocation can be performed in the same chunk
299 return next_alloc;
300 } else {
301 // relocation must be performed in the next chunk
302 VTBufferChunk* next_chunk = chunk->next();
303 assert(next_chunk != NULL, "Because we are compacting, there should be enough chunks");
304 return (address)next_chunk->first_alloc();
305 }
306 }
307
308 oop VTBuffer::relocate_return_value(JavaThread* thread, void* alloc_ptr, oop obj) {
309 assert(!Universe::heap()->is_in_reserved(obj), "This method should never be called on Java heap allocated values");
310 assert(obj->klass()->is_value(), "Sanity check");
311 if (!VTBuffer::is_value_allocated_after(obj, alloc_ptr)) return obj;
312 ValueKlass* vk = ValueKlass::cast(obj->klass());
313 address current_ptr = (address)thread->vt_alloc_ptr();
314 VTBufferChunk* current_chunk = VTBufferChunk::chunk(current_ptr);
315 address previous_ptr = (address)alloc_ptr;
316 if (previous_ptr == NULL) {
317 VTBufferChunk* c = VTBufferChunk::chunk(obj);
318 while (c->prev() != NULL) c = c->prev();
319 previous_ptr = (address)c->first_alloc();
320 }
321 VTBufferChunk* previous_chunk = VTBufferChunk::chunk(previous_ptr);
322 address dest;
323 if ((address)obj != previous_ptr) {
324 if (previous_chunk == current_chunk
325 && (previous_ptr + vk->size_helper() * HeapWordSize) < previous_chunk->alloc_limit()) {
326 dest = previous_ptr;
327 } else {
328 assert(previous_chunk->next() != NULL, "Should not happen");
329 dest = (address)previous_chunk->next()->first_alloc();
330 }
331 // Copying header
332 memcpy(dest, obj, vk->first_field_offset());
333 // Copying value content
334 vk->value_store(((char*)(address)obj) + vk->first_field_offset(),
335 dest + vk->first_field_offset(), false, true);
336 } else {
337 dest = (address)obj;
338 }
339 VTBufferChunk* last = VTBufferChunk::chunk(dest);
340 thread->set_vt_alloc_limit(last->alloc_limit());
341 void* new_alloc_ptr = MIN2((void*)(dest + vk->size_helper() * HeapWordSize), last->alloc_limit());
342 thread->set_vt_alloc_ptr(new_alloc_ptr);
343 assert(VTBufferChunk::chunk(thread->vt_alloc_limit()) == VTBufferChunk::chunk(thread->vt_alloc_ptr()), "Sanity check");
344 VTBufferChunk* del = last->next();
345 last->set_next(NULL);
346 while (del != NULL) {
347 VTBufferChunk* tmp = del->next();
348 VTBuffer::recycle_chunk(thread, del);
349 del = tmp;
350 }
351 return (oop)dest;
352 }
353
354 // This method is called to recycle VTBuffer memory when the VM has detected
355 // that too much memory is being consumed in the current frame context. This
356 // can only happen when the method contains at least one loop in which new
357 // values are created.
358 void VTBuffer::recycle_vt_in_frame(JavaThread* thread, frame* f) {
359 Ticks begin, end;
360 Ticks step1, step2, step3, step4, step5, step6, step7;
361 int returned_chunks = 0;
362
363 if (ReportVTBufferRecyclingTimes) {
364 begin = Ticks::now();
365 }
366 assert(f->is_interpreted_frame(), "only interpreted frames are using VT buffering so far");
367 ResourceMark rm(thread);
368
369 // 1 - allocate relocation table
370 Method* m = f->interpreter_frame_method();
371 int max_entries = m->max_locals() + m->max_stack();
372 VT_relocation_entry* reloc_table = NEW_RESOURCE_ARRAY_IN_THREAD(thread, struct VT_relocation_entry, max_entries);
373 int n_entries = 0;
374 if (ReportVTBufferRecyclingTimes) {
375 step1 = Ticks::now();
376 }
377
378 {
379 // No GC should occur during the phases 2->5
380 // either because the mark word (usually containing the pointer
381 // to the Java mirror) is used for marking, or because the values are being relocated
382 NoSafepointVerifier nsv;
383
384 // 2 - marking phase + populate relocation table
385 BufferedValuesMarking marking_closure = BufferedValuesMarking(f, reloc_table, max_entries, &n_entries);
386 f->buffered_values_interpreted_do(&marking_closure);
387 if (ReportVTBufferRecyclingTimes) {
388 step2 = Ticks::now();
389 }
390
391 if (n_entries > 0) {
392 // 3 - sort relocation table entries and compute compaction
393 qsort(reloc_table, n_entries, sizeof(struct VT_relocation_entry), compare_reloc_entries);
394 if (f->interpreter_frame_vt_alloc_ptr() == NULL) {
395 VTBufferChunk* chunk = VTBufferChunk::chunk(reloc_table[0].old_ptr);
396 while (chunk->prev() != NULL) chunk = chunk->prev();
397 //f->interpreter_frame_set_vt_alloc_ptr((intptr_t*)chunk->first_alloc());
398 reloc_table[0].new_ptr = (address)chunk->first_alloc();
399 } else {
400 reloc_table[0].new_ptr = (address)f->interpreter_frame_vt_alloc_ptr();
401 }
402 ((oop)reloc_table[0].old_ptr)->set_mark((markOop)reloc_table[0].new_ptr);
403 for (int i = 1; i < n_entries; i++) {
404 reloc_table[i].new_ptr = relocate_value(reloc_table[i].old_ptr, reloc_table[i-1].new_ptr,
405 InstanceKlass::cast(((oop)reloc_table[i-1].old_ptr)->klass())->size_helper());
406 ((oop)reloc_table[i].old_ptr)->set_mark((markOop)reloc_table[i].new_ptr);
407 }
408 if (ReportVTBufferRecyclingTimes) {
409 step3 = Ticks::now();
410 }
411
412 // 4 - update pointers
413 BufferedValuesPointersUpdate update_closure = BufferedValuesPointersUpdate(f);
414 f->buffered_values_interpreted_do(&update_closure);
415 if (ReportVTBufferRecyclingTimes) {
416 step4 = Ticks::now();
417 }
418
419 // 5 - relocate values
420 for (int i = 0; i < n_entries; i++) {
421 if (reloc_table[i].old_ptr != reloc_table[i].new_ptr) {
422 assert(VTBufferChunk::chunk(reloc_table[i].old_ptr)->owner() == Thread::current(), "Sanity check");
423 assert(VTBufferChunk::chunk(reloc_table[i].new_ptr)->owner() == Thread::current(), "Sanity check");
424 InstanceKlass* ik_old = InstanceKlass::cast(((oop)reloc_table[i].old_ptr)->klass());
425 // instead of memcpy, a value_store() might be required here
426 memcpy(reloc_table[i].new_ptr, reloc_table[i].old_ptr, ik_old->size_helper() * HeapWordSize);
427 }
428 // Restoring the mark word
429 ((oop)reloc_table[i].new_ptr)->set_mark(reloc_table[i].mark_word);
430 }
431 if (ReportVTBufferRecyclingTimes) {
432 step5 = Ticks::now();
433 }
434
435 oop last_oop = (oop)reloc_table[n_entries - 1].new_ptr;
436 assert(last_oop->is_value(), "sanity check");
437 assert(VTBufferChunk::chunk((address)last_oop)->owner() == Thread::current(), "Sanity check");
438 VTBufferChunk* last_chunk = VTBufferChunk::chunk(last_oop);
439 InstanceKlass* ik = InstanceKlass::cast(last_oop->klass());
440 thread->set_vt_alloc_limit(last_chunk->alloc_limit());
441 void* new_alloc_ptr = MIN2((void*)((address)last_oop + ik->size_helper() * HeapWordSize), thread->vt_alloc_limit());
442 thread->set_vt_alloc_ptr(new_alloc_ptr);
443 assert(VTBufferChunk::chunk(thread->vt_alloc_ptr())->owner() == Thread::current(), "Sanity check");
444 assert(VTBufferChunk::chunk(thread->vt_alloc_limit()) == VTBufferChunk::chunk(thread->vt_alloc_ptr()), "Sanity check");
445 if (ReportVTBufferRecyclingTimes) {
446 step6 = Ticks::now();
447 }
448
449 // 7 - free/return unused chunks
450 VTBufferChunk* last = VTBufferChunk::chunk(thread->vt_alloc_ptr());
451 VTBufferChunk* del = last->next();
452 last->set_next(NULL);
453 while (del != NULL) {
454 returned_chunks++;
455 VTBufferChunk* tmp = del->next();
456 VTBuffer::recycle_chunk(thread, del);
457 del = tmp;
458 }
459 if (ReportVTBufferRecyclingTimes) {
460 step7 = Ticks::now();
461 }
462 } else {
463 f->interpreter_frame_set_vt_alloc_ptr((intptr_t*)thread->vt_alloc_ptr());
464 }
465 }
466
467 // 8 - free relocation table
468 FREE_RESOURCE_ARRAY(struct VT_relocation_entry, reloc_table, max_entries);
469
470 if (ReportVTBufferRecyclingTimes) {
471 end = Ticks::now();
472 ResourceMark rm(thread);
473 tty->print_cr("VTBufferRecyling: %s : %s.%s %s : " JLONG_FORMAT "us",
474 thread->name(),
475 f->interpreter_frame_method()->klass_name()->as_C_string(),
476 f->interpreter_frame_method()->name()->as_C_string(),
477 f->interpreter_frame_method()->signature()->as_C_string(),
478 (end.value() - begin.value()) / 1000);
479 tty->print("Step1 : " JLONG_FORMAT "ns ", step1.value() - begin.value());
480 tty->print("Step2 : " JLONG_FORMAT "ns ", step2.value() - step1.value());
481 tty->print("Step3 : " JLONG_FORMAT "ns ", step3.value() - step2.value());
482 tty->print("Step4 : " JLONG_FORMAT "ns ", step4.value() - step3.value());
483 tty->print("Step5 : " JLONG_FORMAT "ns ", step5.value() - step4.value());
484 tty->print("Step6 : " JLONG_FORMAT "ns ", step6.value() - step5.value());
485 tty->print("Step7 : " JLONG_FORMAT "ns ", step7.value() - step6.value());
486 tty->print("Step8 : " JLONG_FORMAT "ns ", end.value() - step7.value());
487 tty->print_cr("Returned chunks: %d", returned_chunks);
488 }
489 }
490
491 void BufferedValuesMarking::do_buffered_value(oop* p) {
492 assert(!Universe::heap()->is_in_reserved_or_null(*p), "Sanity check");
493 if (VTBuffer::value_belongs_to_frame(*p, _frame)) {
494 if (!(*p)->mark()->is_marked()) {
495 assert(*_index < _size, "index outside of relocation table range");
496 _reloc_table[*_index].old_ptr = (address)*p;
497 _reloc_table[*_index].chunk_index = VTBufferChunk::chunk(*p)->index();
498 _reloc_table[*_index].mark_word = (*p)->mark();
499 *_index = (*_index) + 1;
500 (*p)->set_mark((*p)->mark()->set_marked());
501 }
502 }
503 }
504
505 void BufferedValuesPointersUpdate::do_buffered_value(oop* p) {
506 assert(!Universe::heap()->is_in_reserved_or_null(*p), "Sanity check");
507 // might be coded more efficiently just by checking mark word is not NULL
508 if (VTBuffer::value_belongs_to_frame(*p, _frame)) {
509 *p = (oop)(*p)->mark();
510 }
511 }
512
513 BufferedValuesDealiaser::BufferedValuesDealiaser(JavaThread* thread) {
514 Thread* current = Thread::current();
515 assert(current->buffered_values_dealiaser() == NULL, "Must not be used twice concurrently");
516 VTBuffer::Mark mark = VTBuffer::switch_mark(thread->current_vtbuffer_mark());
517 _target = thread;
518 _current_mark = mark;
519 thread->set_current_vtbuffer_mark(_current_mark);
520 current->_buffered_values_dealiaser = this;
521 }
522
523 void BufferedValuesDealiaser::oops_do(OopClosure* f, oop value) {
524
525 assert(VTBuffer::is_in_vt_buffer((oopDesc*)value), "Should only be called on buffered values");
526
527 intptr_t mark = *(intptr_t*)(value)->mark_addr();
528 if ((mark & VTBuffer::mark_mask) == _current_mark) {
529 return;
530 }
531
532 ValueKlass* vk = ValueKlass::cast(value->klass());
533
534 oop mirror = (oopDesc*)((intptr_t)value->mark() & (intptr_t)~VTBuffer::mark_mask);
535 assert(oopDesc::is_oop(mirror), "Sanity check");
536 value->set_mark((markOop)mirror);
537
538 vk->iterate_over_inside_oops(f, value);
539
540 intptr_t new_mark_word = ((intptr_t) (oopDesc*)(value->mark()))
541 | (intptr_t)_current_mark;
542 value->set_mark(markOop((oopDesc*)new_mark_word));
543 }
544
545 BufferedValuesDealiaser::~BufferedValuesDealiaser() {
546 assert(Thread::current()->buffered_values_dealiaser() != NULL, "Should not be NULL");
547 assert(_target->current_vtbuffer_mark() == _current_mark, "Must be the same");
548 Thread::current()->_buffered_values_dealiaser = NULL;
549 }