1 /*
2 * Copyright (c) 2002, 2011, 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 *
230
231 void PSPromotionManager::flush_labs() {
232 assert(stacks_empty(), "Attempt to flush lab with live stack");
233
234 // If either promotion lab fills up, we can flush the
235 // lab but not refill it, so check first.
236 assert(!_young_lab.is_flushed() || _young_gen_is_full, "Sanity");
237 if (!_young_lab.is_flushed())
238 _young_lab.flush();
239
240 assert(!_old_lab.is_flushed() || _old_gen_is_full, "Sanity");
241 if (!_old_lab.is_flushed())
242 _old_lab.flush();
243
244 // Let PSScavenge know if we overflowed
245 if (_young_gen_is_full) {
246 PSScavenge::set_survivor_overflow(true);
247 }
248 }
249
250 //
251 // This method is pretty bulky. It would be nice to split it up
252 // into smaller submethods, but we need to be careful not to hurt
253 // performance.
254 //
255
256 oop PSPromotionManager::copy_to_survivor_space(oop o) {
257 assert(PSScavenge::should_scavenge(&o), "Sanity");
258
259 oop new_obj = NULL;
260
261 // NOTE! We must be very careful with any methods that access the mark
262 // in o. There may be multiple threads racing on it, and it may be forwarded
263 // at any time. Do not use oop methods for accessing the mark!
264 markOop test_mark = o->mark();
265
266 // The same test as "o->is_forwarded()"
267 if (!test_mark->is_marked()) {
268 bool new_obj_is_tenured = false;
269 size_t new_obj_size = o->size();
270
271 // Find the objects age, MT safe.
272 int age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
273 test_mark->displaced_mark_helper()->age() : test_mark->age();
274
275 // Try allocating obj in to-space (unless too old)
276 if (age < PSScavenge::tenuring_threshold()) {
277 new_obj = (oop) _young_lab.allocate(new_obj_size);
278 if (new_obj == NULL && !_young_gen_is_full) {
279 // Do we allocate directly, or flush and refill?
280 if (new_obj_size > (YoungPLABSize / 2)) {
281 // Allocate this object directly
282 new_obj = (oop)young_space()->cas_allocate(new_obj_size);
283 } else {
284 // Flush and fill
285 _young_lab.flush();
286
287 HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
288 if (lab_base != NULL) {
289 _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
290 // Try the young lab allocation again.
291 new_obj = (oop) _young_lab.allocate(new_obj_size);
292 } else {
293 _young_gen_is_full = true;
294 }
295 }
296 }
297 }
298
299 // Otherwise try allocating obj tenured
300 if (new_obj == NULL) {
301 #ifndef PRODUCT
302 if (Universe::heap()->promotion_should_fail()) {
303 return oop_promotion_failed(o, test_mark);
304 }
305 #endif // #ifndef PRODUCT
306
307 new_obj = (oop) _old_lab.allocate(new_obj_size);
308 new_obj_is_tenured = true;
309
310 if (new_obj == NULL) {
311 if (!_old_gen_is_full) {
312 // Do we allocate directly, or flush and refill?
313 if (new_obj_size > (OldPLABSize / 2)) {
314 // Allocate this object directly
315 new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
316 } else {
317 // Flush and fill
318 _old_lab.flush();
319
320 HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
321 if(lab_base != NULL) {
322 _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
323 // Try the old lab allocation again.
324 new_obj = (oop) _old_lab.allocate(new_obj_size);
325 }
326 }
327 }
328
329 // This is the promotion failed test, and code handling.
330 // The code belongs here for two reasons. It is slightly
331 // different thatn the code below, and cannot share the
332 // CAS testing code. Keeping the code here also minimizes
333 // the impact on the common case fast path code.
334
335 if (new_obj == NULL) {
336 _old_gen_is_full = true;
337 return oop_promotion_failed(o, test_mark);
338 }
339 }
340 }
341
342 assert(new_obj != NULL, "allocation should have succeeded");
343
344 // Copy obj
345 Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);
346
347 // Now we have to CAS in the header.
348 if (o->cas_forward_to(new_obj, test_mark)) {
349 // We won any races, we "own" this object.
350 assert(new_obj == o->forwardee(), "Sanity");
351
352 // Increment age if obj still in new generation. Now that
353 // we're dealing with a markOop that cannot change, it is
354 // okay to use the non mt safe oop methods.
355 if (!new_obj_is_tenured) {
356 new_obj->incr_age();
357 assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
358 }
359
360 // Do the size comparison first with new_obj_size, which we
361 // already have. Hopefully, only a few objects are larger than
362 // _min_array_size_for_chunking, and most of them will be arrays.
363 // So, the is->objArray() test would be very infrequent.
364 if (new_obj_size > _min_array_size_for_chunking &&
365 new_obj->is_objArray() &&
366 PSChunkLargeArrays) {
367 // we'll chunk it
368 oop* const masked_o = mask_chunked_array_oop(o);
369 push_depth(masked_o);
370 TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
371 } else {
372 // we'll just push its contents
373 new_obj->push_contents(this);
374 }
375 } else {
376 // We lost, someone else "owns" this object
377 guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
378
379 // Try to deallocate the space. If it was directly allocated we cannot
380 // deallocate it, so we have to test. If the deallocation fails,
381 // overwrite with a filler object.
382 if (new_obj_is_tenured) {
383 if (!_old_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
384 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
385 }
386 } else if (!_young_lab.unallocate_object((HeapWord*) new_obj, new_obj_size)) {
387 CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
388 }
389
390 // don't update this before the unallocation!
391 new_obj = o->forwardee();
392 }
393 } else {
394 assert(o->is_forwarded(), "Sanity");
395 new_obj = o->forwardee();
396 }
397
398 #ifdef DEBUG
399 // This code must come after the CAS test, or it will print incorrect
400 // information.
401 if (TraceScavenge) {
402 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (" SIZE_FORMAT ")}",
403 PSScavenge::should_scavenge(&new_obj) ? "copying" : "tenuring",
404 new_obj->blueprint()->internal_name(), o, new_obj, new_obj->size());
405 }
406 #endif
407
408 return new_obj;
409 }
410
411 template <class T> void PSPromotionManager::process_array_chunk_work(
412 oop obj,
413 int start, int end) {
414 assert(start <= end, "invariant");
415 T* const base = (T*)objArrayOop(obj)->base();
416 T* p = base + start;
417 T* const chunk_end = base + end;
418 while (p < chunk_end) {
419 if (PSScavenge::should_scavenge(p)) {
420 claim_or_forward_depth(p);
421 }
422 ++p;
423 }
424 }
425
426 void PSPromotionManager::process_array_chunk(oop old) {
427 assert(PSChunkLargeArrays, "invariant");
428 assert(old->is_objArray(), "invariant");
429 assert(old->is_forwarded(), "invariant");
430
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1 /*
2 * Copyright (c) 2002, 2012, 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 *
230
231 void PSPromotionManager::flush_labs() {
232 assert(stacks_empty(), "Attempt to flush lab with live stack");
233
234 // If either promotion lab fills up, we can flush the
235 // lab but not refill it, so check first.
236 assert(!_young_lab.is_flushed() || _young_gen_is_full, "Sanity");
237 if (!_young_lab.is_flushed())
238 _young_lab.flush();
239
240 assert(!_old_lab.is_flushed() || _old_gen_is_full, "Sanity");
241 if (!_old_lab.is_flushed())
242 _old_lab.flush();
243
244 // Let PSScavenge know if we overflowed
245 if (_young_gen_is_full) {
246 PSScavenge::set_survivor_overflow(true);
247 }
248 }
249
250 template <class T> void PSPromotionManager::process_array_chunk_work(
251 oop obj,
252 int start, int end) {
253 assert(start <= end, "invariant");
254 T* const base = (T*)objArrayOop(obj)->base();
255 T* p = base + start;
256 T* const chunk_end = base + end;
257 while (p < chunk_end) {
258 if (PSScavenge::should_scavenge(p)) {
259 claim_or_forward_depth(p);
260 }
261 ++p;
262 }
263 }
264
265 void PSPromotionManager::process_array_chunk(oop old) {
266 assert(PSChunkLargeArrays, "invariant");
267 assert(old->is_objArray(), "invariant");
268 assert(old->is_forwarded(), "invariant");
269
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