1 #ifdef USE_PRAGMA_IDENT_SRC 2 #pragma ident "@(#)asParNewGeneration.cpp 1.11 07/05/05 17:05:25 JVM" 3 #endif 4 /* 5 * Copyright 2005-2008 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/_asParNewGeneration.cpp.incl" 30 31 ASParNewGeneration::ASParNewGeneration(ReservedSpace rs, 32 size_t initial_byte_size, 33 size_t min_byte_size, 34 int level) : 35 ParNewGeneration(rs, initial_byte_size, level), 36 _min_gen_size(min_byte_size) {} 37 38 const char* ASParNewGeneration::name() const { 39 return "adaptive size par new generation"; 40 } 41 42 void ASParNewGeneration::adjust_desired_tenuring_threshold() { 43 assert(UseAdaptiveSizePolicy, 44 "Should only be used with UseAdaptiveSizePolicy"); 45 } 46 47 void ASParNewGeneration::resize(size_t eden_size, size_t survivor_size) { 48 // Resize the generation if needed. If the generation resize 49 // reports false, do not attempt to resize the spaces. 50 if (resize_generation(eden_size, survivor_size)) { 51 // Then we lay out the spaces inside the generation 52 resize_spaces(eden_size, survivor_size); 53 54 space_invariants(); 55 56 if (PrintAdaptiveSizePolicy && Verbose) { 57 gclog_or_tty->print_cr("Young generation size: " 58 "desired eden: " SIZE_FORMAT " survivor: " SIZE_FORMAT 59 " used: " SIZE_FORMAT " capacity: " SIZE_FORMAT 60 " gen limits: " SIZE_FORMAT " / " SIZE_FORMAT, 61 eden_size, survivor_size, used(), capacity(), 62 max_gen_size(), min_gen_size()); 63 } 64 } 65 } 66 67 size_t ASParNewGeneration::available_to_min_gen() { 68 assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant"); 69 return virtual_space()->committed_size() - min_gen_size(); 70 } 71 72 // This method assumes that from-space has live data and that 73 // any shrinkage of the young gen is limited by location of 74 // from-space. 75 size_t ASParNewGeneration::available_to_live() const { 76 #undef SHRINKS_AT_END_OF_EDEN 77 #ifdef SHRINKS_AT_END_OF_EDEN 78 size_t delta_in_survivor = 0; 79 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); 80 const size_t space_alignment = heap->intra_heap_alignment(); 81 const size_t gen_alignment = heap->object_heap_alignment(); 82 83 MutableSpace* space_shrinking = NULL; 84 if (from_space()->end() > to_space()->end()) { 85 space_shrinking = from_space(); 86 } else { 87 space_shrinking = to_space(); 88 } 89 90 // Include any space that is committed but not included in 91 // the survivor spaces. 92 assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(), 93 "Survivor space beyond high end"); 94 size_t unused_committed = pointer_delta(virtual_space()->high(), 95 space_shrinking->end(), sizeof(char)); 96 97 if (space_shrinking->is_empty()) { 98 // Don't let the space shrink to 0 99 assert(space_shrinking->capacity_in_bytes() >= space_alignment, 100 "Space is too small"); 101 delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment; 102 } else { 103 delta_in_survivor = pointer_delta(space_shrinking->end(), 104 space_shrinking->top(), 105 sizeof(char)); 106 } 107 108 size_t delta_in_bytes = unused_committed + delta_in_survivor; 109 delta_in_bytes = align_size_down(delta_in_bytes, gen_alignment); 110 return delta_in_bytes; 111 #else 112 // The only space available for shrinking is in to-space if it 113 // is above from-space. 114 if (to()->bottom() > from()->bottom()) { 115 const size_t alignment = os::vm_page_size(); 116 if (to()->capacity() < alignment) { 117 return 0; 118 } else { 119 return to()->capacity() - alignment; 120 } 121 } else { 122 return 0; 123 } 124 #endif 125 } 126 127 // Return the number of bytes available for resizing down the young 128 // generation. This is the minimum of 129 // input "bytes" 130 // bytes to the minimum young gen size 131 // bytes to the size currently being used + some small extra 132 size_t ASParNewGeneration::limit_gen_shrink (size_t bytes) { 133 // Allow shrinkage into the current eden but keep eden large enough 134 // to maintain the minimum young gen size 135 bytes = MIN3(bytes, available_to_min_gen(), available_to_live()); 136 return align_size_down(bytes, os::vm_page_size()); 137 } 138 139 // Note that the the alignment used is the OS page size as 140 // opposed to an alignment associated with the virtual space 141 // (as is done in the ASPSYoungGen/ASPSOldGen) 142 bool ASParNewGeneration::resize_generation(size_t eden_size, 143 size_t survivor_size) { 144 const size_t alignment = os::vm_page_size(); 145 size_t orig_size = virtual_space()->committed_size(); 146 bool size_changed = false; 147 148 // There used to be this guarantee there. 149 // guarantee ((eden_size + 2*survivor_size) <= _max_gen_size, "incorrect input arguments"); 150 // Code below forces this requirement. In addition the desired eden 151 // size and disired survivor sizes are desired goals and may 152 // exceed the total generation size. 153 154 assert(min_gen_size() <= orig_size && orig_size <= max_gen_size(), 155 "just checking"); 156 157 // Adjust new generation size 158 const size_t eden_plus_survivors = 159 align_size_up(eden_size + 2 * survivor_size, alignment); 160 size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_gen_size()), 161 min_gen_size()); 162 assert(desired_size <= max_gen_size(), "just checking"); 163 164 if (desired_size > orig_size) { 165 // Grow the generation 166 size_t change = desired_size - orig_size; 167 assert(change % alignment == 0, "just checking"); 168 if (expand(change)) { 169 return false; // Error if we fail to resize! 170 } 171 size_changed = true; 172 } else if (desired_size < orig_size) { 173 size_t desired_change = orig_size - desired_size; 174 assert(desired_change % alignment == 0, "just checking"); 175 176 desired_change = limit_gen_shrink(desired_change); 177 178 if (desired_change > 0) { 179 virtual_space()->shrink_by(desired_change); 180 reset_survivors_after_shrink(); 181 182 size_changed = true; 183 } 184 } else { 185 if (Verbose && PrintGC) { 186 if (orig_size == max_gen_size()) { 187 gclog_or_tty->print_cr("ASParNew generation size at maximum: " 188 SIZE_FORMAT "K", orig_size/K); 189 } else if (orig_size == min_gen_size()) { 190 gclog_or_tty->print_cr("ASParNew generation size at minium: " 191 SIZE_FORMAT "K", orig_size/K); 192 } 193 } 194 } 195 196 if (size_changed) { 197 MemRegion cmr((HeapWord*)virtual_space()->low(), 198 (HeapWord*)virtual_space()->high()); 199 GenCollectedHeap::heap()->barrier_set()->resize_covered_region(cmr); 200 201 if (Verbose && PrintGC) { 202 size_t current_size = virtual_space()->committed_size(); 203 gclog_or_tty->print_cr("ASParNew generation size changed: " 204 SIZE_FORMAT "K->" SIZE_FORMAT "K", 205 orig_size/K, current_size/K); 206 } 207 } 208 209 guarantee(eden_plus_survivors <= virtual_space()->committed_size() || 210 virtual_space()->committed_size() == max_gen_size(), "Sanity"); 211 212 return true; 213 } 214 215 void ASParNewGeneration::reset_survivors_after_shrink() { 216 217 GenCollectedHeap* gch = GenCollectedHeap::heap(); 218 HeapWord* new_end = (HeapWord*)virtual_space()->high(); 219 220 if (from()->end() > to()->end()) { 221 assert(new_end >= from()->end(), "Shrinking past from-space"); 222 } else { 223 assert(new_end >= to()->bottom(), "Shrink was too large"); 224 // Was there a shrink of the survivor space? 225 if (new_end < to()->end()) { 226 MemRegion mr(to()->bottom(), new_end); 227 to()->initialize(mr, 228 SpaceDecorator::DontClear, 229 SpaceDecorator::DontMangle); 230 } 231 } 232 } 233 void ASParNewGeneration::resize_spaces(size_t requested_eden_size, 234 size_t requested_survivor_size) { 235 assert(UseAdaptiveSizePolicy, "sanity check"); 236 assert(requested_eden_size > 0 && requested_survivor_size > 0, 237 "just checking"); 238 CollectedHeap* heap = Universe::heap(); 239 assert(heap->kind() == CollectedHeap::GenCollectedHeap, "Sanity"); 240 241 242 // We require eden and to space to be empty 243 if ((!eden()->is_empty()) || (!to()->is_empty())) { 244 return; 245 } 246 247 size_t cur_eden_size = eden()->capacity(); 248 249 if (PrintAdaptiveSizePolicy && Verbose) { 250 gclog_or_tty->print_cr("ASParNew::resize_spaces(requested_eden_size: " 251 SIZE_FORMAT 252 ", requested_survivor_size: " SIZE_FORMAT ")", 253 requested_eden_size, requested_survivor_size); 254 gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") " 255 SIZE_FORMAT, 256 eden()->bottom(), 257 eden()->end(), 258 pointer_delta(eden()->end(), 259 eden()->bottom(), 260 sizeof(char))); 261 gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") " 262 SIZE_FORMAT, 263 from()->bottom(), 264 from()->end(), 265 pointer_delta(from()->end(), 266 from()->bottom(), 267 sizeof(char))); 268 gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") " 269 SIZE_FORMAT, 270 to()->bottom(), 271 to()->end(), 272 pointer_delta( to()->end(), 273 to()->bottom(), 274 sizeof(char))); 275 } 276 277 // There's nothing to do if the new sizes are the same as the current 278 if (requested_survivor_size == to()->capacity() && 279 requested_survivor_size == from()->capacity() && 280 requested_eden_size == eden()->capacity()) { 281 if (PrintAdaptiveSizePolicy && Verbose) { 282 gclog_or_tty->print_cr(" capacities are the right sizes, returning"); 283 } 284 return; 285 } 286 287 char* eden_start = (char*)eden()->bottom(); 288 char* eden_end = (char*)eden()->end(); 289 char* from_start = (char*)from()->bottom(); 290 char* from_end = (char*)from()->end(); 291 char* to_start = (char*)to()->bottom(); 292 char* to_end = (char*)to()->end(); 293 294 const size_t alignment = os::vm_page_size(); 295 const bool maintain_minimum = 296 (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size(); 297 298 // Check whether from space is below to space 299 if (from_start < to_start) { 300 // Eden, from, to 301 if (PrintAdaptiveSizePolicy && Verbose) { 302 gclog_or_tty->print_cr(" Eden, from, to:"); 303 } 304 305 // Set eden 306 // "requested_eden_size" is a goal for the size of eden 307 // and may not be attainable. "eden_size" below is 308 // calculated based on the location of from-space and 309 // the goal for the size of eden. from-space is 310 // fixed in place because it contains live data. 311 // The calculation is done this way to avoid 32bit 312 // overflow (i.e., eden_start + requested_eden_size 313 // may too large for representation in 32bits). 314 size_t eden_size; 315 if (maintain_minimum) { 316 // Only make eden larger than the requested size if 317 // the minimum size of the generation has to be maintained. 318 // This could be done in general but policy at a higher 319 // level is determining a requested size for eden and that 320 // should be honored unless there is a fundamental reason. 321 eden_size = pointer_delta(from_start, 322 eden_start, 323 sizeof(char)); 324 } else { 325 eden_size = MIN2(requested_eden_size, 326 pointer_delta(from_start, eden_start, sizeof(char))); 327 } 328 329 eden_size = align_size_down(eden_size, alignment); 330 eden_end = eden_start + eden_size; 331 assert(eden_end >= eden_start, "addition overflowed") 332 333 // To may resize into from space as long as it is clear of live data. 334 // From space must remain page aligned, though, so we need to do some 335 // extra calculations. 336 337 // First calculate an optimal to-space 338 to_end = (char*)virtual_space()->high(); 339 to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size, 340 sizeof(char)); 341 342 // Does the optimal to-space overlap from-space? 343 if (to_start < (char*)from()->end()) { 344 // Calculate the minimum offset possible for from_end 345 size_t from_size = pointer_delta(from()->top(), from_start, sizeof(char)); 346 347 // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME! 348 if (from_size == 0) { 349 from_size = alignment; 350 } else { 351 from_size = align_size_up(from_size, alignment); 352 } 353 354 from_end = from_start + from_size; 355 assert(from_end > from_start, "addition overflow or from_size problem"); 356 357 guarantee(from_end <= (char*)from()->end(), "from_end moved to the right"); 358 359 // Now update to_start with the new from_end 360 to_start = MAX2(from_end, to_start); 361 } else { 362 // If shrinking, move to-space down to abut the end of from-space 363 // so that shrinking will move to-space down. If not shrinking 364 // to-space is moving up to allow for growth on the next expansion. 365 if (requested_eden_size <= cur_eden_size) { 366 to_start = from_end; 367 if (to_start + requested_survivor_size > to_start) { 368 to_end = to_start + requested_survivor_size; 369 } 370 } 371 // else leave to_end pointing to the high end of the virtual space. 372 } 373 374 guarantee(to_start != to_end, "to space is zero sized"); 375 376 if (PrintAdaptiveSizePolicy && Verbose) { 377 gclog_or_tty->print_cr(" [eden_start .. eden_end): " 378 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, 379 eden_start, 380 eden_end, 381 pointer_delta(eden_end, eden_start, sizeof(char))); 382 gclog_or_tty->print_cr(" [from_start .. from_end): " 383 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, 384 from_start, 385 from_end, 386 pointer_delta(from_end, from_start, sizeof(char))); 387 gclog_or_tty->print_cr(" [ to_start .. to_end): " 388 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, 389 to_start, 390 to_end, 391 pointer_delta( to_end, to_start, sizeof(char))); 392 } 393 } else { 394 // Eden, to, from 395 if (PrintAdaptiveSizePolicy && Verbose) { 396 gclog_or_tty->print_cr(" Eden, to, from:"); 397 } 398 399 // Calculate the to-space boundaries based on 400 // the start of from-space. 401 to_end = from_start; 402 to_start = (char*)pointer_delta(from_start, 403 (char*)requested_survivor_size, 404 sizeof(char)); 405 // Calculate the ideal eden boundaries. 406 // eden_end is already at the bottom of the generation 407 assert(eden_start == virtual_space()->low(), 408 "Eden is not starting at the low end of the virtual space"); 409 if (eden_start + requested_eden_size >= eden_start) { 410 eden_end = eden_start + requested_eden_size; 411 } else { 412 eden_end = to_start; 413 } 414 415 // Does eden intrude into to-space? to-space 416 // gets priority but eden is not allowed to shrink 417 // to 0. 418 if (eden_end > to_start) { 419 eden_end = to_start; 420 } 421 422 // Don't let eden shrink down to 0 or less. 423 eden_end = MAX2(eden_end, eden_start + alignment); 424 assert(eden_start + alignment >= eden_start, "Overflow"); 425 426 size_t eden_size; 427 if (maintain_minimum) { 428 // Use all the space available. 429 eden_end = MAX2(eden_end, to_start); 430 eden_size = pointer_delta(eden_end, eden_start, sizeof(char)); 431 eden_size = MIN2(eden_size, cur_eden_size); 432 } else { 433 eden_size = pointer_delta(eden_end, eden_start, sizeof(char)); 434 } 435 eden_size = align_size_down(eden_size, alignment); 436 assert(maintain_minimum || eden_size <= requested_eden_size, 437 "Eden size is too large"); 438 assert(eden_size >= alignment, "Eden size is too small"); 439 eden_end = eden_start + eden_size; 440 441 // Move to-space down to eden. 442 if (requested_eden_size < cur_eden_size) { 443 to_start = eden_end; 444 if (to_start + requested_survivor_size > to_start) { 445 to_end = MIN2(from_start, to_start + requested_survivor_size); 446 } else { 447 to_end = from_start; 448 } 449 } 450 451 // eden_end may have moved so again make sure 452 // the to-space and eden don't overlap. 453 to_start = MAX2(eden_end, to_start); 454 455 // from-space 456 size_t from_used = from()->used(); 457 if (requested_survivor_size > from_used) { 458 if (from_start + requested_survivor_size >= from_start) { 459 from_end = from_start + requested_survivor_size; 460 } 461 if (from_end > virtual_space()->high()) { 462 from_end = virtual_space()->high(); 463 } 464 } 465 466 assert(to_start >= eden_end, "to-space should be above eden"); 467 if (PrintAdaptiveSizePolicy && Verbose) { 468 gclog_or_tty->print_cr(" [eden_start .. eden_end): " 469 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, 470 eden_start, 471 eden_end, 472 pointer_delta(eden_end, eden_start, sizeof(char))); 473 gclog_or_tty->print_cr(" [ to_start .. to_end): " 474 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, 475 to_start, 476 to_end, 477 pointer_delta( to_end, to_start, sizeof(char))); 478 gclog_or_tty->print_cr(" [from_start .. from_end): " 479 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, 480 from_start, 481 from_end, 482 pointer_delta(from_end, from_start, sizeof(char))); 483 } 484 } 485 486 487 guarantee((HeapWord*)from_start <= from()->bottom(), 488 "from start moved to the right"); 489 guarantee((HeapWord*)from_end >= from()->top(), 490 "from end moved into live data"); 491 assert(is_object_aligned((intptr_t)eden_start), "checking alignment"); 492 assert(is_object_aligned((intptr_t)from_start), "checking alignment"); 493 assert(is_object_aligned((intptr_t)to_start), "checking alignment"); 494 495 MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end); 496 MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end); 497 MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end); 498 499 // Let's make sure the call to initialize doesn't reset "top"! 500 HeapWord* old_from_top = from()->top(); 501 502 // For PrintAdaptiveSizePolicy block below 503 size_t old_from = from()->capacity(); 504 size_t old_to = to()->capacity(); 505 506 // If not clearing the spaces, do some checking to verify that 507 // the spaces are already mangled. 508 509 // Must check mangling before the spaces are reshaped. Otherwise, 510 // the bottom or end of one space may have moved into another 511 // a failure of the check may not correctly indicate which space 512 // is not properly mangled. 513 if (ZapUnusedHeapArea) { 514 HeapWord* limit = (HeapWord*) virtual_space()->high(); 515 eden()->check_mangled_unused_area(limit); 516 from()->check_mangled_unused_area(limit); 517 to()->check_mangled_unused_area(limit); 518 } 519 520 // The call to initialize NULL's the next compaction space 521 eden()->initialize(edenMR, 522 SpaceDecorator::Clear, 523 SpaceDecorator::DontMangle); 524 eden()->set_next_compaction_space(from()); 525 to()->initialize(toMR , 526 SpaceDecorator::Clear, 527 SpaceDecorator::DontMangle); 528 from()->initialize(fromMR, 529 SpaceDecorator::DontClear, 530 SpaceDecorator::DontMangle); 531 532 assert(from()->top() == old_from_top, "from top changed!"); 533 534 if (PrintAdaptiveSizePolicy) { 535 GenCollectedHeap* gch = GenCollectedHeap::heap(); 536 assert(gch->kind() == CollectedHeap::GenCollectedHeap, "Sanity"); 537 538 gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: " 539 "collection: %d " 540 "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> " 541 "(" SIZE_FORMAT ", " SIZE_FORMAT ") ", 542 gch->total_collections(), 543 old_from, old_to, 544 from()->capacity(), 545 to()->capacity()); 546 gclog_or_tty->cr(); 547 } 548 } 549 550 void ASParNewGeneration::compute_new_size() { 551 GenCollectedHeap* gch = GenCollectedHeap::heap(); 552 assert(gch->kind() == CollectedHeap::GenCollectedHeap, 553 "not a CMS generational heap"); 554 555 556 CMSAdaptiveSizePolicy* size_policy = 557 (CMSAdaptiveSizePolicy*)gch->gen_policy()->size_policy(); 558 assert(size_policy->is_gc_cms_adaptive_size_policy(), 559 "Wrong type of size policy"); 560 561 size_t survived = from()->used(); 562 if (!survivor_overflow()) { 563 // Keep running averages on how much survived 564 size_policy->avg_survived()->sample(survived); 565 } else { 566 size_t promoted = 567 (size_t) next_gen()->gc_stats()->avg_promoted()->last_sample(); 568 assert(promoted < gch->capacity(), "Conversion problem?"); 569 size_t survived_guess = survived + promoted; 570 size_policy->avg_survived()->sample(survived_guess); 571 } 572 573 size_t survivor_limit = max_survivor_size(); 574 _tenuring_threshold = 575 size_policy->compute_survivor_space_size_and_threshold( 576 _survivor_overflow, 577 _tenuring_threshold, 578 survivor_limit); 579 size_policy->avg_young_live()->sample(used()); 580 size_policy->avg_eden_live()->sample(eden()->used()); 581 582 size_policy->compute_young_generation_free_space(eden()->capacity(), 583 max_gen_size()); 584 585 resize(size_policy->calculated_eden_size_in_bytes(), 586 size_policy->calculated_survivor_size_in_bytes()); 587 588 if (UsePerfData) { 589 CMSGCAdaptivePolicyCounters* counters = 590 (CMSGCAdaptivePolicyCounters*) gch->collector_policy()->counters(); 591 assert(counters->kind() == 592 GCPolicyCounters::CMSGCAdaptivePolicyCountersKind, 593 "Wrong kind of counters"); 594 counters->update_tenuring_threshold(_tenuring_threshold); 595 counters->update_survivor_overflowed(_survivor_overflow); 596 counters->update_young_capacity(capacity()); 597 } 598 } 599 600 601 #ifndef PRODUCT 602 // Changes from PSYoungGen version 603 // value of "alignment" 604 void ASParNewGeneration::space_invariants() { 605 const size_t alignment = os::vm_page_size(); 606 607 // Currently, our eden size cannot shrink to zero 608 guarantee(eden()->capacity() >= alignment, "eden too small"); 609 guarantee(from()->capacity() >= alignment, "from too small"); 610 guarantee(to()->capacity() >= alignment, "to too small"); 611 612 // Relationship of spaces to each other 613 char* eden_start = (char*)eden()->bottom(); 614 char* eden_end = (char*)eden()->end(); 615 char* from_start = (char*)from()->bottom(); 616 char* from_end = (char*)from()->end(); 617 char* to_start = (char*)to()->bottom(); 618 char* to_end = (char*)to()->end(); 619 620 guarantee(eden_start >= virtual_space()->low(), "eden bottom"); 621 guarantee(eden_start < eden_end, "eden space consistency"); 622 guarantee(from_start < from_end, "from space consistency"); 623 guarantee(to_start < to_end, "to space consistency"); 624 625 // Check whether from space is below to space 626 if (from_start < to_start) { 627 // Eden, from, to 628 guarantee(eden_end <= from_start, "eden/from boundary"); 629 guarantee(from_end <= to_start, "from/to boundary"); 630 guarantee(to_end <= virtual_space()->high(), "to end"); 631 } else { 632 // Eden, to, from 633 guarantee(eden_end <= to_start, "eden/to boundary"); 634 guarantee(to_end <= from_start, "to/from boundary"); 635 guarantee(from_end <= virtual_space()->high(), "from end"); 636 } 637 638 // More checks that the virtual space is consistent with the spaces 639 assert(virtual_space()->committed_size() >= 640 (eden()->capacity() + 641 to()->capacity() + 642 from()->capacity()), "Committed size is inconsistent"); 643 assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(), 644 "Space invariant"); 645 char* eden_top = (char*)eden()->top(); 646 char* from_top = (char*)from()->top(); 647 char* to_top = (char*)to()->top(); 648 assert(eden_top <= virtual_space()->high(), "eden top"); 649 assert(from_top <= virtual_space()->high(), "from top"); 650 assert(to_top <= virtual_space()->high(), "to top"); 651 } 652 #endif