1 /*
2 * Copyright (c) 2005, 2010, 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_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp"
27 #include "gc_implementation/concurrentMarkSweep/cmsGCAdaptivePolicyCounters.hpp"
28 #include "gc_implementation/parNew/asParNewGeneration.hpp"
29 #include "gc_implementation/parNew/parNewGeneration.hpp"
30 #include "gc_implementation/shared/markSweep.inline.hpp"
31 #include "gc_implementation/shared/spaceDecorator.hpp"
32 #include "memory/defNewGeneration.inline.hpp"
33 #include "memory/referencePolicy.hpp"
34 #include "oops/markOop.inline.hpp"
35 #include "oops/oop.pcgc.inline.hpp"
36
37 ASParNewGeneration::ASParNewGeneration(ReservedSpace rs,
38 size_t initial_byte_size,
39 size_t min_byte_size,
40 int level) :
41 ParNewGeneration(rs, initial_byte_size, level),
42 _min_gen_size(min_byte_size) {}
43
44 const char* ASParNewGeneration::name() const {
45 return "adaptive size par new generation";
46 }
47
48 void ASParNewGeneration::adjust_desired_tenuring_threshold() {
49 assert(UseAdaptiveSizePolicy,
50 "Should only be used with UseAdaptiveSizePolicy");
51 }
52
53 void ASParNewGeneration::resize(size_t eden_size, size_t survivor_size) {
54 // Resize the generation if needed. If the generation resize
55 // reports false, do not attempt to resize the spaces.
56 if (resize_generation(eden_size, survivor_size)) {
57 // Then we lay out the spaces inside the generation
58 resize_spaces(eden_size, survivor_size);
59
60 space_invariants();
61
62 if (PrintAdaptiveSizePolicy && Verbose) {
63 gclog_or_tty->print_cr("Young generation size: "
64 "desired eden: " SIZE_FORMAT " survivor: " SIZE_FORMAT
65 " used: " SIZE_FORMAT " capacity: " SIZE_FORMAT
66 " gen limits: " SIZE_FORMAT " / " SIZE_FORMAT,
67 eden_size, survivor_size, used(), capacity(),
68 max_gen_size(), min_gen_size());
69 }
70 }
71 }
72
73 size_t ASParNewGeneration::available_to_min_gen() {
74 assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant");
75 return virtual_space()->committed_size() - min_gen_size();
76 }
77
78 // This method assumes that from-space has live data and that
79 // any shrinkage of the young gen is limited by location of
80 // from-space.
81 size_t ASParNewGeneration::available_to_live() const {
82 #undef SHRINKS_AT_END_OF_EDEN
83 #ifdef SHRINKS_AT_END_OF_EDEN
84 size_t delta_in_survivor = 0;
85 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
86 const size_t space_alignment = heap->intra_heap_alignment();
87 const size_t gen_alignment = heap->object_heap_alignment();
88
89 MutableSpace* space_shrinking = NULL;
90 if (from_space()->end() > to_space()->end()) {
91 space_shrinking = from_space();
92 } else {
93 space_shrinking = to_space();
94 }
95
96 // Include any space that is committed but not included in
97 // the survivor spaces.
98 assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(),
99 "Survivor space beyond high end");
100 size_t unused_committed = pointer_delta(virtual_space()->high(),
101 space_shrinking->end(), sizeof(char));
102
103 if (space_shrinking->is_empty()) {
104 // Don't let the space shrink to 0
105 assert(space_shrinking->capacity_in_bytes() >= space_alignment,
106 "Space is too small");
107 delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment;
108 } else {
109 delta_in_survivor = pointer_delta(space_shrinking->end(),
110 space_shrinking->top(),
111 sizeof(char));
112 }
113
114 size_t delta_in_bytes = unused_committed + delta_in_survivor;
115 delta_in_bytes = align_size_down(delta_in_bytes, gen_alignment);
116 return delta_in_bytes;
117 #else
118 // The only space available for shrinking is in to-space if it
119 // is above from-space.
120 if (to()->bottom() > from()->bottom()) {
121 const size_t alignment = os::vm_page_size();
122 if (to()->capacity() < alignment) {
123 return 0;
124 } else {
125 return to()->capacity() - alignment;
126 }
127 } else {
128 return 0;
129 }
130 #endif
131 }
132
133 // Return the number of bytes available for resizing down the young
134 // generation. This is the minimum of
135 // input "bytes"
136 // bytes to the minimum young gen size
137 // bytes to the size currently being used + some small extra
138 size_t ASParNewGeneration::limit_gen_shrink (size_t bytes) {
139 // Allow shrinkage into the current eden but keep eden large enough
140 // to maintain the minimum young gen size
141 bytes = MIN3(bytes, available_to_min_gen(), available_to_live());
142 return align_size_down(bytes, os::vm_page_size());
143 }
144
145 // Note that the the alignment used is the OS page size as
146 // opposed to an alignment associated with the virtual space
147 // (as is done in the ASPSYoungGen/ASPSOldGen)
148 bool ASParNewGeneration::resize_generation(size_t eden_size,
149 size_t survivor_size) {
150 const size_t alignment = os::vm_page_size();
151 size_t orig_size = virtual_space()->committed_size();
152 bool size_changed = false;
153
154 // There used to be this guarantee there.
155 // guarantee ((eden_size + 2*survivor_size) <= _max_gen_size, "incorrect input arguments");
156 // Code below forces this requirement. In addition the desired eden
157 // size and disired survivor sizes are desired goals and may
158 // exceed the total generation size.
159
160 assert(min_gen_size() <= orig_size && orig_size <= max_gen_size(),
161 "just checking");
162
163 // Adjust new generation size
164 const size_t eden_plus_survivors =
165 align_size_up(eden_size + 2 * survivor_size, alignment);
166 size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_gen_size()),
167 min_gen_size());
168 assert(desired_size <= max_gen_size(), "just checking");
169
170 if (desired_size > orig_size) {
171 // Grow the generation
172 size_t change = desired_size - orig_size;
173 assert(change % alignment == 0, "just checking");
174 if (expand(change)) {
175 return false; // Error if we fail to resize!
176 }
177 size_changed = true;
178 } else if (desired_size < orig_size) {
179 size_t desired_change = orig_size - desired_size;
180 assert(desired_change % alignment == 0, "just checking");
181
182 desired_change = limit_gen_shrink(desired_change);
183
184 if (desired_change > 0) {
185 virtual_space()->shrink_by(desired_change);
186 reset_survivors_after_shrink();
187
188 size_changed = true;
189 }
190 } else {
191 if (Verbose && PrintGC) {
192 if (orig_size == max_gen_size()) {
193 gclog_or_tty->print_cr("ASParNew generation size at maximum: "
194 SIZE_FORMAT "K", orig_size/K);
195 } else if (orig_size == min_gen_size()) {
196 gclog_or_tty->print_cr("ASParNew generation size at minium: "
197 SIZE_FORMAT "K", orig_size/K);
198 }
199 }
200 }
201
202 if (size_changed) {
203 MemRegion cmr((HeapWord*)virtual_space()->low(),
204 (HeapWord*)virtual_space()->high());
205 GenCollectedHeap::heap()->barrier_set()->resize_covered_region(cmr);
206
207 if (Verbose && PrintGC) {
208 size_t current_size = virtual_space()->committed_size();
209 gclog_or_tty->print_cr("ASParNew generation size changed: "
210 SIZE_FORMAT "K->" SIZE_FORMAT "K",
211 orig_size/K, current_size/K);
212 }
213 }
214
215 guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
216 virtual_space()->committed_size() == max_gen_size(), "Sanity");
217
218 return true;
219 }
220
221 void ASParNewGeneration::reset_survivors_after_shrink() {
222
223 GenCollectedHeap* gch = GenCollectedHeap::heap();
224 HeapWord* new_end = (HeapWord*)virtual_space()->high();
225
226 if (from()->end() > to()->end()) {
227 assert(new_end >= from()->end(), "Shrinking past from-space");
228 } else {
229 assert(new_end >= to()->bottom(), "Shrink was too large");
230 // Was there a shrink of the survivor space?
231 if (new_end < to()->end()) {
232 MemRegion mr(to()->bottom(), new_end);
233 to()->initialize(mr,
234 SpaceDecorator::DontClear,
235 SpaceDecorator::DontMangle);
236 }
237 }
238 }
239 void ASParNewGeneration::resize_spaces(size_t requested_eden_size,
240 size_t requested_survivor_size) {
241 assert(UseAdaptiveSizePolicy, "sanity check");
242 assert(requested_eden_size > 0 && requested_survivor_size > 0,
243 "just checking");
244 CollectedHeap* heap = Universe::heap();
245 assert(heap->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
246
247
248 // We require eden and to space to be empty
249 if ((!eden()->is_empty()) || (!to()->is_empty())) {
250 return;
251 }
252
253 size_t cur_eden_size = eden()->capacity();
254
255 if (PrintAdaptiveSizePolicy && Verbose) {
256 gclog_or_tty->print_cr("ASParNew::resize_spaces(requested_eden_size: "
257 SIZE_FORMAT
258 ", requested_survivor_size: " SIZE_FORMAT ")",
259 requested_eden_size, requested_survivor_size);
260 gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") "
261 SIZE_FORMAT,
262 eden()->bottom(),
263 eden()->end(),
264 pointer_delta(eden()->end(),
265 eden()->bottom(),
266 sizeof(char)));
267 gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") "
268 SIZE_FORMAT,
269 from()->bottom(),
270 from()->end(),
271 pointer_delta(from()->end(),
272 from()->bottom(),
273 sizeof(char)));
274 gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") "
275 SIZE_FORMAT,
276 to()->bottom(),
277 to()->end(),
278 pointer_delta( to()->end(),
279 to()->bottom(),
280 sizeof(char)));
281 }
282
283 // There's nothing to do if the new sizes are the same as the current
284 if (requested_survivor_size == to()->capacity() &&
285 requested_survivor_size == from()->capacity() &&
286 requested_eden_size == eden()->capacity()) {
287 if (PrintAdaptiveSizePolicy && Verbose) {
288 gclog_or_tty->print_cr(" capacities are the right sizes, returning");
289 }
290 return;
291 }
292
293 char* eden_start = (char*)eden()->bottom();
294 char* eden_end = (char*)eden()->end();
295 char* from_start = (char*)from()->bottom();
296 char* from_end = (char*)from()->end();
297 char* to_start = (char*)to()->bottom();
298 char* to_end = (char*)to()->end();
299
300 const size_t alignment = os::vm_page_size();
301 const bool maintain_minimum =
302 (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
303
304 // Check whether from space is below to space
305 if (from_start < to_start) {
306 // Eden, from, to
307 if (PrintAdaptiveSizePolicy && Verbose) {
308 gclog_or_tty->print_cr(" Eden, from, to:");
309 }
310
311 // Set eden
312 // "requested_eden_size" is a goal for the size of eden
313 // and may not be attainable. "eden_size" below is
314 // calculated based on the location of from-space and
315 // the goal for the size of eden. from-space is
316 // fixed in place because it contains live data.
317 // The calculation is done this way to avoid 32bit
318 // overflow (i.e., eden_start + requested_eden_size
319 // may too large for representation in 32bits).
320 size_t eden_size;
321 if (maintain_minimum) {
322 // Only make eden larger than the requested size if
323 // the minimum size of the generation has to be maintained.
324 // This could be done in general but policy at a higher
325 // level is determining a requested size for eden and that
326 // should be honored unless there is a fundamental reason.
327 eden_size = pointer_delta(from_start,
328 eden_start,
329 sizeof(char));
330 } else {
331 eden_size = MIN2(requested_eden_size,
332 pointer_delta(from_start, eden_start, sizeof(char)));
333 }
334
335 eden_size = align_size_down(eden_size, alignment);
336 eden_end = eden_start + eden_size;
337 assert(eden_end >= eden_start, "addition overflowed");
338
339 // To may resize into from space as long as it is clear of live data.
340 // From space must remain page aligned, though, so we need to do some
341 // extra calculations.
342
343 // First calculate an optimal to-space
344 to_end = (char*)virtual_space()->high();
345 to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
346 sizeof(char));
347
348 // Does the optimal to-space overlap from-space?
349 if (to_start < (char*)from()->end()) {
350 // Calculate the minimum offset possible for from_end
351 size_t from_size = pointer_delta(from()->top(), from_start, sizeof(char));
352
353 // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
354 if (from_size == 0) {
355 from_size = alignment;
356 } else {
357 from_size = align_size_up(from_size, alignment);
358 }
359
360 from_end = from_start + from_size;
361 assert(from_end > from_start, "addition overflow or from_size problem");
362
363 guarantee(from_end <= (char*)from()->end(), "from_end moved to the right");
364
365 // Now update to_start with the new from_end
366 to_start = MAX2(from_end, to_start);
367 } else {
368 // If shrinking, move to-space down to abut the end of from-space
369 // so that shrinking will move to-space down. If not shrinking
370 // to-space is moving up to allow for growth on the next expansion.
371 if (requested_eden_size <= cur_eden_size) {
372 to_start = from_end;
373 if (to_start + requested_survivor_size > to_start) {
374 to_end = to_start + requested_survivor_size;
375 }
376 }
377 // else leave to_end pointing to the high end of the virtual space.
378 }
379
380 guarantee(to_start != to_end, "to space is zero sized");
381
382 if (PrintAdaptiveSizePolicy && Verbose) {
383 gclog_or_tty->print_cr(" [eden_start .. eden_end): "
384 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
385 eden_start,
386 eden_end,
387 pointer_delta(eden_end, eden_start, sizeof(char)));
388 gclog_or_tty->print_cr(" [from_start .. from_end): "
389 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
390 from_start,
391 from_end,
392 pointer_delta(from_end, from_start, sizeof(char)));
393 gclog_or_tty->print_cr(" [ to_start .. to_end): "
394 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
395 to_start,
396 to_end,
397 pointer_delta( to_end, to_start, sizeof(char)));
398 }
399 } else {
400 // Eden, to, from
401 if (PrintAdaptiveSizePolicy && Verbose) {
402 gclog_or_tty->print_cr(" Eden, to, from:");
403 }
404
405 // Calculate the to-space boundaries based on
406 // the start of from-space.
407 to_end = from_start;
408 to_start = (char*)pointer_delta(from_start,
409 (char*)requested_survivor_size,
410 sizeof(char));
411 // Calculate the ideal eden boundaries.
412 // eden_end is already at the bottom of the generation
413 assert(eden_start == virtual_space()->low(),
414 "Eden is not starting at the low end of the virtual space");
415 if (eden_start + requested_eden_size >= eden_start) {
416 eden_end = eden_start + requested_eden_size;
417 } else {
418 eden_end = to_start;
419 }
420
421 // Does eden intrude into to-space? to-space
422 // gets priority but eden is not allowed to shrink
423 // to 0.
424 if (eden_end > to_start) {
425 eden_end = to_start;
426 }
427
428 // Don't let eden shrink down to 0 or less.
429 eden_end = MAX2(eden_end, eden_start + alignment);
430 assert(eden_start + alignment >= eden_start, "Overflow");
431
432 size_t eden_size;
433 if (maintain_minimum) {
434 // Use all the space available.
435 eden_end = MAX2(eden_end, to_start);
436 eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
437 eden_size = MIN2(eden_size, cur_eden_size);
438 } else {
439 eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
440 }
441 eden_size = align_size_down(eden_size, alignment);
442 assert(maintain_minimum || eden_size <= requested_eden_size,
443 "Eden size is too large");
444 assert(eden_size >= alignment, "Eden size is too small");
445 eden_end = eden_start + eden_size;
446
447 // Move to-space down to eden.
448 if (requested_eden_size < cur_eden_size) {
449 to_start = eden_end;
450 if (to_start + requested_survivor_size > to_start) {
451 to_end = MIN2(from_start, to_start + requested_survivor_size);
452 } else {
453 to_end = from_start;
454 }
455 }
456
457 // eden_end may have moved so again make sure
458 // the to-space and eden don't overlap.
459 to_start = MAX2(eden_end, to_start);
460
461 // from-space
462 size_t from_used = from()->used();
463 if (requested_survivor_size > from_used) {
464 if (from_start + requested_survivor_size >= from_start) {
465 from_end = from_start + requested_survivor_size;
466 }
467 if (from_end > virtual_space()->high()) {
468 from_end = virtual_space()->high();
469 }
470 }
471
472 assert(to_start >= eden_end, "to-space should be above eden");
473 if (PrintAdaptiveSizePolicy && Verbose) {
474 gclog_or_tty->print_cr(" [eden_start .. eden_end): "
475 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
476 eden_start,
477 eden_end,
478 pointer_delta(eden_end, eden_start, sizeof(char)));
479 gclog_or_tty->print_cr(" [ to_start .. to_end): "
480 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
481 to_start,
482 to_end,
483 pointer_delta( to_end, to_start, sizeof(char)));
484 gclog_or_tty->print_cr(" [from_start .. from_end): "
485 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
486 from_start,
487 from_end,
488 pointer_delta(from_end, from_start, sizeof(char)));
489 }
490 }
491
492
493 guarantee((HeapWord*)from_start <= from()->bottom(),
494 "from start moved to the right");
495 guarantee((HeapWord*)from_end >= from()->top(),
496 "from end moved into live data");
497 assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
498 assert(is_object_aligned((intptr_t)from_start), "checking alignment");
499 assert(is_object_aligned((intptr_t)to_start), "checking alignment");
500
501 MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
502 MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end);
503 MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
504
505 // Let's make sure the call to initialize doesn't reset "top"!
506 HeapWord* old_from_top = from()->top();
507
508 // For PrintAdaptiveSizePolicy block below
509 size_t old_from = from()->capacity();
510 size_t old_to = to()->capacity();
511
512 // If not clearing the spaces, do some checking to verify that
513 // the spaces are already mangled.
514
515 // Must check mangling before the spaces are reshaped. Otherwise,
516 // the bottom or end of one space may have moved into another
517 // a failure of the check may not correctly indicate which space
518 // is not properly mangled.
519 if (ZapUnusedHeapArea) {
520 HeapWord* limit = (HeapWord*) virtual_space()->high();
521 eden()->check_mangled_unused_area(limit);
522 from()->check_mangled_unused_area(limit);
523 to()->check_mangled_unused_area(limit);
524 }
525
526 // The call to initialize NULL's the next compaction space
527 eden()->initialize(edenMR,
528 SpaceDecorator::Clear,
529 SpaceDecorator::DontMangle);
530 eden()->set_next_compaction_space(from());
531 to()->initialize(toMR ,
532 SpaceDecorator::Clear,
533 SpaceDecorator::DontMangle);
534 from()->initialize(fromMR,
535 SpaceDecorator::DontClear,
536 SpaceDecorator::DontMangle);
537
538 assert(from()->top() == old_from_top, "from top changed!");
539
540 if (PrintAdaptiveSizePolicy) {
541 GenCollectedHeap* gch = GenCollectedHeap::heap();
542 assert(gch->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
543
544 gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
545 "collection: %d "
546 "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
547 "(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
548 gch->total_collections(),
549 old_from, old_to,
550 from()->capacity(),
551 to()->capacity());
552 gclog_or_tty->cr();
553 }
554 }
555
556 void ASParNewGeneration::compute_new_size() {
557 GenCollectedHeap* gch = GenCollectedHeap::heap();
558 assert(gch->kind() == CollectedHeap::GenCollectedHeap,
559 "not a CMS generational heap");
560
561
562 CMSAdaptiveSizePolicy* size_policy =
563 (CMSAdaptiveSizePolicy*)gch->gen_policy()->size_policy();
564 assert(size_policy->is_gc_cms_adaptive_size_policy(),
565 "Wrong type of size policy");
566
567 size_t survived = from()->used();
568 if (!survivor_overflow()) {
569 // Keep running averages on how much survived
570 size_policy->avg_survived()->sample(survived);
571 } else {
572 size_t promoted =
573 (size_t) next_gen()->gc_stats()->avg_promoted()->last_sample();
574 assert(promoted < gch->capacity(), "Conversion problem?");
575 size_t survived_guess = survived + promoted;
576 size_policy->avg_survived()->sample(survived_guess);
577 }
578
579 size_t survivor_limit = max_survivor_size();
580 _tenuring_threshold =
581 size_policy->compute_survivor_space_size_and_threshold(
582 _survivor_overflow,
583 _tenuring_threshold,
584 survivor_limit);
585 size_policy->avg_young_live()->sample(used());
586 size_policy->avg_eden_live()->sample(eden()->used());
587
588 size_policy->compute_eden_space_size(eden()->capacity(),
589 max_gen_size());
590
591 resize(size_policy->calculated_eden_size_in_bytes(),
592 size_policy->calculated_survivor_size_in_bytes());
593
594 if (UsePerfData) {
595 CMSGCAdaptivePolicyCounters* counters =
596 (CMSGCAdaptivePolicyCounters*) gch->collector_policy()->counters();
597 assert(counters->kind() ==
598 GCPolicyCounters::CMSGCAdaptivePolicyCountersKind,
599 "Wrong kind of counters");
600 counters->update_tenuring_threshold(_tenuring_threshold);
601 counters->update_survivor_overflowed(_survivor_overflow);
602 counters->update_young_capacity(capacity());
603 }
604 }
605
606
607 #ifndef PRODUCT
608 // Changes from PSYoungGen version
609 // value of "alignment"
610 void ASParNewGeneration::space_invariants() {
611 const size_t alignment = os::vm_page_size();
612
613 // Currently, our eden size cannot shrink to zero
614 guarantee(eden()->capacity() >= alignment, "eden too small");
615 guarantee(from()->capacity() >= alignment, "from too small");
616 guarantee(to()->capacity() >= alignment, "to too small");
617
618 // Relationship of spaces to each other
619 char* eden_start = (char*)eden()->bottom();
620 char* eden_end = (char*)eden()->end();
621 char* from_start = (char*)from()->bottom();
622 char* from_end = (char*)from()->end();
623 char* to_start = (char*)to()->bottom();
624 char* to_end = (char*)to()->end();
625
626 guarantee(eden_start >= virtual_space()->low(), "eden bottom");
627 guarantee(eden_start < eden_end, "eden space consistency");
628 guarantee(from_start < from_end, "from space consistency");
629 guarantee(to_start < to_end, "to space consistency");
630
631 // Check whether from space is below to space
632 if (from_start < to_start) {
633 // Eden, from, to
634 guarantee(eden_end <= from_start, "eden/from boundary");
635 guarantee(from_end <= to_start, "from/to boundary");
636 guarantee(to_end <= virtual_space()->high(), "to end");
637 } else {
638 // Eden, to, from
639 guarantee(eden_end <= to_start, "eden/to boundary");
640 guarantee(to_end <= from_start, "to/from boundary");
641 guarantee(from_end <= virtual_space()->high(), "from end");
642 }
643
644 // More checks that the virtual space is consistent with the spaces
645 assert(virtual_space()->committed_size() >=
646 (eden()->capacity() +
647 to()->capacity() +
648 from()->capacity()), "Committed size is inconsistent");
649 assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
650 "Space invariant");
651 char* eden_top = (char*)eden()->top();
652 char* from_top = (char*)from()->top();
653 char* to_top = (char*)to()->top();
654 assert(eden_top <= virtual_space()->high(), "eden top");
655 assert(from_top <= virtual_space()->high(), "from top");
656 assert(to_top <= virtual_space()->high(), "to top");
657 }
658 #endif