src/share/vm/gc_implementation/parNew/asParNewGeneration.cpp

Tue, 13 Apr 2010 13:52:10 -0700

author
jmasa
date
Tue, 13 Apr 2010 13:52:10 -0700
changeset 1822
0bfd3fb24150
parent 704
850fdf70db2b
child 1844
cff162798819
permissions
-rw-r--r--

6858496: Clear all SoftReferences before an out-of-memory due to GC overhead limit.
Summary: Ensure a full GC that clears SoftReferences before throwing an out-of-memory
Reviewed-by: ysr, jcoomes

duke@435 1 /*
xdono@631 2 * Copyright 2005-2008 Sun Microsystems, Inc. All Rights Reserved.
duke@435 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435 4 *
duke@435 5 * This code is free software; you can redistribute it and/or modify it
duke@435 6 * under the terms of the GNU General Public License version 2 only, as
duke@435 7 * published by the Free Software Foundation.
duke@435 8 *
duke@435 9 * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435 12 * version 2 for more details (a copy is included in the LICENSE file that
duke@435 13 * accompanied this code).
duke@435 14 *
duke@435 15 * You should have received a copy of the GNU General Public License version
duke@435 16 * 2 along with this work; if not, write to the Free Software Foundation,
duke@435 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435 18 *
duke@435 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435 20 * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435 21 * have any questions.
duke@435 22 *
duke@435 23 */
duke@435 24
duke@435 25 # include "incls/_precompiled.incl"
duke@435 26 # include "incls/_asParNewGeneration.cpp.incl"
duke@435 27
duke@435 28 ASParNewGeneration::ASParNewGeneration(ReservedSpace rs,
duke@435 29 size_t initial_byte_size,
duke@435 30 size_t min_byte_size,
duke@435 31 int level) :
duke@435 32 ParNewGeneration(rs, initial_byte_size, level),
duke@435 33 _min_gen_size(min_byte_size) {}
duke@435 34
duke@435 35 const char* ASParNewGeneration::name() const {
duke@435 36 return "adaptive size par new generation";
duke@435 37 }
duke@435 38
duke@435 39 void ASParNewGeneration::adjust_desired_tenuring_threshold() {
duke@435 40 assert(UseAdaptiveSizePolicy,
duke@435 41 "Should only be used with UseAdaptiveSizePolicy");
duke@435 42 }
duke@435 43
duke@435 44 void ASParNewGeneration::resize(size_t eden_size, size_t survivor_size) {
duke@435 45 // Resize the generation if needed. If the generation resize
duke@435 46 // reports false, do not attempt to resize the spaces.
duke@435 47 if (resize_generation(eden_size, survivor_size)) {
duke@435 48 // Then we lay out the spaces inside the generation
duke@435 49 resize_spaces(eden_size, survivor_size);
duke@435 50
duke@435 51 space_invariants();
duke@435 52
duke@435 53 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 54 gclog_or_tty->print_cr("Young generation size: "
duke@435 55 "desired eden: " SIZE_FORMAT " survivor: " SIZE_FORMAT
duke@435 56 " used: " SIZE_FORMAT " capacity: " SIZE_FORMAT
duke@435 57 " gen limits: " SIZE_FORMAT " / " SIZE_FORMAT,
duke@435 58 eden_size, survivor_size, used(), capacity(),
duke@435 59 max_gen_size(), min_gen_size());
duke@435 60 }
duke@435 61 }
duke@435 62 }
duke@435 63
duke@435 64 size_t ASParNewGeneration::available_to_min_gen() {
duke@435 65 assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant");
duke@435 66 return virtual_space()->committed_size() - min_gen_size();
duke@435 67 }
duke@435 68
duke@435 69 // This method assumes that from-space has live data and that
duke@435 70 // any shrinkage of the young gen is limited by location of
duke@435 71 // from-space.
duke@435 72 size_t ASParNewGeneration::available_to_live() const {
duke@435 73 #undef SHRINKS_AT_END_OF_EDEN
duke@435 74 #ifdef SHRINKS_AT_END_OF_EDEN
duke@435 75 size_t delta_in_survivor = 0;
duke@435 76 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
jmasa@448 77 const size_t space_alignment = heap->intra_heap_alignment();
jmasa@448 78 const size_t gen_alignment = heap->object_heap_alignment();
duke@435 79
duke@435 80 MutableSpace* space_shrinking = NULL;
duke@435 81 if (from_space()->end() > to_space()->end()) {
duke@435 82 space_shrinking = from_space();
duke@435 83 } else {
duke@435 84 space_shrinking = to_space();
duke@435 85 }
duke@435 86
duke@435 87 // Include any space that is committed but not included in
duke@435 88 // the survivor spaces.
duke@435 89 assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(),
duke@435 90 "Survivor space beyond high end");
duke@435 91 size_t unused_committed = pointer_delta(virtual_space()->high(),
duke@435 92 space_shrinking->end(), sizeof(char));
duke@435 93
duke@435 94 if (space_shrinking->is_empty()) {
duke@435 95 // Don't let the space shrink to 0
duke@435 96 assert(space_shrinking->capacity_in_bytes() >= space_alignment,
duke@435 97 "Space is too small");
duke@435 98 delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment;
duke@435 99 } else {
duke@435 100 delta_in_survivor = pointer_delta(space_shrinking->end(),
duke@435 101 space_shrinking->top(),
duke@435 102 sizeof(char));
duke@435 103 }
duke@435 104
duke@435 105 size_t delta_in_bytes = unused_committed + delta_in_survivor;
duke@435 106 delta_in_bytes = align_size_down(delta_in_bytes, gen_alignment);
duke@435 107 return delta_in_bytes;
duke@435 108 #else
duke@435 109 // The only space available for shrinking is in to-space if it
duke@435 110 // is above from-space.
duke@435 111 if (to()->bottom() > from()->bottom()) {
duke@435 112 const size_t alignment = os::vm_page_size();
duke@435 113 if (to()->capacity() < alignment) {
duke@435 114 return 0;
duke@435 115 } else {
duke@435 116 return to()->capacity() - alignment;
duke@435 117 }
duke@435 118 } else {
duke@435 119 return 0;
duke@435 120 }
duke@435 121 #endif
duke@435 122 }
duke@435 123
duke@435 124 // Return the number of bytes available for resizing down the young
duke@435 125 // generation. This is the minimum of
duke@435 126 // input "bytes"
duke@435 127 // bytes to the minimum young gen size
duke@435 128 // bytes to the size currently being used + some small extra
duke@435 129 size_t ASParNewGeneration::limit_gen_shrink (size_t bytes) {
duke@435 130 // Allow shrinkage into the current eden but keep eden large enough
duke@435 131 // to maintain the minimum young gen size
duke@435 132 bytes = MIN3(bytes, available_to_min_gen(), available_to_live());
duke@435 133 return align_size_down(bytes, os::vm_page_size());
duke@435 134 }
duke@435 135
duke@435 136 // Note that the the alignment used is the OS page size as
duke@435 137 // opposed to an alignment associated with the virtual space
duke@435 138 // (as is done in the ASPSYoungGen/ASPSOldGen)
duke@435 139 bool ASParNewGeneration::resize_generation(size_t eden_size,
duke@435 140 size_t survivor_size) {
duke@435 141 const size_t alignment = os::vm_page_size();
duke@435 142 size_t orig_size = virtual_space()->committed_size();
duke@435 143 bool size_changed = false;
duke@435 144
duke@435 145 // There used to be this guarantee there.
duke@435 146 // guarantee ((eden_size + 2*survivor_size) <= _max_gen_size, "incorrect input arguments");
duke@435 147 // Code below forces this requirement. In addition the desired eden
duke@435 148 // size and disired survivor sizes are desired goals and may
duke@435 149 // exceed the total generation size.
duke@435 150
duke@435 151 assert(min_gen_size() <= orig_size && orig_size <= max_gen_size(),
duke@435 152 "just checking");
duke@435 153
duke@435 154 // Adjust new generation size
duke@435 155 const size_t eden_plus_survivors =
duke@435 156 align_size_up(eden_size + 2 * survivor_size, alignment);
duke@435 157 size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_gen_size()),
duke@435 158 min_gen_size());
duke@435 159 assert(desired_size <= max_gen_size(), "just checking");
duke@435 160
duke@435 161 if (desired_size > orig_size) {
duke@435 162 // Grow the generation
duke@435 163 size_t change = desired_size - orig_size;
duke@435 164 assert(change % alignment == 0, "just checking");
jmasa@698 165 if (expand(change)) {
duke@435 166 return false; // Error if we fail to resize!
duke@435 167 }
duke@435 168 size_changed = true;
duke@435 169 } else if (desired_size < orig_size) {
duke@435 170 size_t desired_change = orig_size - desired_size;
duke@435 171 assert(desired_change % alignment == 0, "just checking");
duke@435 172
duke@435 173 desired_change = limit_gen_shrink(desired_change);
duke@435 174
duke@435 175 if (desired_change > 0) {
duke@435 176 virtual_space()->shrink_by(desired_change);
duke@435 177 reset_survivors_after_shrink();
duke@435 178
duke@435 179 size_changed = true;
duke@435 180 }
duke@435 181 } else {
duke@435 182 if (Verbose && PrintGC) {
duke@435 183 if (orig_size == max_gen_size()) {
duke@435 184 gclog_or_tty->print_cr("ASParNew generation size at maximum: "
duke@435 185 SIZE_FORMAT "K", orig_size/K);
duke@435 186 } else if (orig_size == min_gen_size()) {
duke@435 187 gclog_or_tty->print_cr("ASParNew generation size at minium: "
duke@435 188 SIZE_FORMAT "K", orig_size/K);
duke@435 189 }
duke@435 190 }
duke@435 191 }
duke@435 192
duke@435 193 if (size_changed) {
duke@435 194 MemRegion cmr((HeapWord*)virtual_space()->low(),
duke@435 195 (HeapWord*)virtual_space()->high());
duke@435 196 GenCollectedHeap::heap()->barrier_set()->resize_covered_region(cmr);
duke@435 197
duke@435 198 if (Verbose && PrintGC) {
duke@435 199 size_t current_size = virtual_space()->committed_size();
duke@435 200 gclog_or_tty->print_cr("ASParNew generation size changed: "
duke@435 201 SIZE_FORMAT "K->" SIZE_FORMAT "K",
duke@435 202 orig_size/K, current_size/K);
duke@435 203 }
duke@435 204 }
duke@435 205
duke@435 206 guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
duke@435 207 virtual_space()->committed_size() == max_gen_size(), "Sanity");
duke@435 208
duke@435 209 return true;
duke@435 210 }
duke@435 211
duke@435 212 void ASParNewGeneration::reset_survivors_after_shrink() {
duke@435 213
duke@435 214 GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435 215 HeapWord* new_end = (HeapWord*)virtual_space()->high();
duke@435 216
duke@435 217 if (from()->end() > to()->end()) {
duke@435 218 assert(new_end >= from()->end(), "Shrinking past from-space");
duke@435 219 } else {
duke@435 220 assert(new_end >= to()->bottom(), "Shrink was too large");
duke@435 221 // Was there a shrink of the survivor space?
duke@435 222 if (new_end < to()->end()) {
duke@435 223 MemRegion mr(to()->bottom(), new_end);
jmasa@698 224 to()->initialize(mr,
jmasa@698 225 SpaceDecorator::DontClear,
jmasa@698 226 SpaceDecorator::DontMangle);
duke@435 227 }
duke@435 228 }
duke@435 229 }
duke@435 230 void ASParNewGeneration::resize_spaces(size_t requested_eden_size,
duke@435 231 size_t requested_survivor_size) {
duke@435 232 assert(UseAdaptiveSizePolicy, "sanity check");
duke@435 233 assert(requested_eden_size > 0 && requested_survivor_size > 0,
duke@435 234 "just checking");
duke@435 235 CollectedHeap* heap = Universe::heap();
duke@435 236 assert(heap->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
duke@435 237
duke@435 238
duke@435 239 // We require eden and to space to be empty
duke@435 240 if ((!eden()->is_empty()) || (!to()->is_empty())) {
duke@435 241 return;
duke@435 242 }
duke@435 243
duke@435 244 size_t cur_eden_size = eden()->capacity();
duke@435 245
duke@435 246 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 247 gclog_or_tty->print_cr("ASParNew::resize_spaces(requested_eden_size: "
duke@435 248 SIZE_FORMAT
duke@435 249 ", requested_survivor_size: " SIZE_FORMAT ")",
duke@435 250 requested_eden_size, requested_survivor_size);
duke@435 251 gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435 252 SIZE_FORMAT,
duke@435 253 eden()->bottom(),
duke@435 254 eden()->end(),
duke@435 255 pointer_delta(eden()->end(),
duke@435 256 eden()->bottom(),
duke@435 257 sizeof(char)));
duke@435 258 gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435 259 SIZE_FORMAT,
duke@435 260 from()->bottom(),
duke@435 261 from()->end(),
duke@435 262 pointer_delta(from()->end(),
duke@435 263 from()->bottom(),
duke@435 264 sizeof(char)));
duke@435 265 gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435 266 SIZE_FORMAT,
duke@435 267 to()->bottom(),
duke@435 268 to()->end(),
duke@435 269 pointer_delta( to()->end(),
duke@435 270 to()->bottom(),
duke@435 271 sizeof(char)));
duke@435 272 }
duke@435 273
duke@435 274 // There's nothing to do if the new sizes are the same as the current
duke@435 275 if (requested_survivor_size == to()->capacity() &&
duke@435 276 requested_survivor_size == from()->capacity() &&
duke@435 277 requested_eden_size == eden()->capacity()) {
duke@435 278 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 279 gclog_or_tty->print_cr(" capacities are the right sizes, returning");
duke@435 280 }
duke@435 281 return;
duke@435 282 }
duke@435 283
duke@435 284 char* eden_start = (char*)eden()->bottom();
duke@435 285 char* eden_end = (char*)eden()->end();
duke@435 286 char* from_start = (char*)from()->bottom();
duke@435 287 char* from_end = (char*)from()->end();
duke@435 288 char* to_start = (char*)to()->bottom();
duke@435 289 char* to_end = (char*)to()->end();
duke@435 290
duke@435 291 const size_t alignment = os::vm_page_size();
duke@435 292 const bool maintain_minimum =
duke@435 293 (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
duke@435 294
duke@435 295 // Check whether from space is below to space
duke@435 296 if (from_start < to_start) {
duke@435 297 // Eden, from, to
duke@435 298 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 299 gclog_or_tty->print_cr(" Eden, from, to:");
duke@435 300 }
duke@435 301
duke@435 302 // Set eden
duke@435 303 // "requested_eden_size" is a goal for the size of eden
duke@435 304 // and may not be attainable. "eden_size" below is
duke@435 305 // calculated based on the location of from-space and
duke@435 306 // the goal for the size of eden. from-space is
duke@435 307 // fixed in place because it contains live data.
duke@435 308 // The calculation is done this way to avoid 32bit
duke@435 309 // overflow (i.e., eden_start + requested_eden_size
duke@435 310 // may too large for representation in 32bits).
duke@435 311 size_t eden_size;
duke@435 312 if (maintain_minimum) {
duke@435 313 // Only make eden larger than the requested size if
duke@435 314 // the minimum size of the generation has to be maintained.
duke@435 315 // This could be done in general but policy at a higher
duke@435 316 // level is determining a requested size for eden and that
duke@435 317 // should be honored unless there is a fundamental reason.
duke@435 318 eden_size = pointer_delta(from_start,
duke@435 319 eden_start,
duke@435 320 sizeof(char));
duke@435 321 } else {
duke@435 322 eden_size = MIN2(requested_eden_size,
duke@435 323 pointer_delta(from_start, eden_start, sizeof(char)));
duke@435 324 }
duke@435 325
duke@435 326 eden_size = align_size_down(eden_size, alignment);
duke@435 327 eden_end = eden_start + eden_size;
duke@435 328 assert(eden_end >= eden_start, "addition overflowed")
duke@435 329
duke@435 330 // To may resize into from space as long as it is clear of live data.
duke@435 331 // From space must remain page aligned, though, so we need to do some
duke@435 332 // extra calculations.
duke@435 333
duke@435 334 // First calculate an optimal to-space
duke@435 335 to_end = (char*)virtual_space()->high();
duke@435 336 to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
duke@435 337 sizeof(char));
duke@435 338
duke@435 339 // Does the optimal to-space overlap from-space?
duke@435 340 if (to_start < (char*)from()->end()) {
duke@435 341 // Calculate the minimum offset possible for from_end
duke@435 342 size_t from_size = pointer_delta(from()->top(), from_start, sizeof(char));
duke@435 343
duke@435 344 // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
duke@435 345 if (from_size == 0) {
duke@435 346 from_size = alignment;
duke@435 347 } else {
duke@435 348 from_size = align_size_up(from_size, alignment);
duke@435 349 }
duke@435 350
duke@435 351 from_end = from_start + from_size;
duke@435 352 assert(from_end > from_start, "addition overflow or from_size problem");
duke@435 353
duke@435 354 guarantee(from_end <= (char*)from()->end(), "from_end moved to the right");
duke@435 355
duke@435 356 // Now update to_start with the new from_end
duke@435 357 to_start = MAX2(from_end, to_start);
duke@435 358 } else {
duke@435 359 // If shrinking, move to-space down to abut the end of from-space
duke@435 360 // so that shrinking will move to-space down. If not shrinking
duke@435 361 // to-space is moving up to allow for growth on the next expansion.
duke@435 362 if (requested_eden_size <= cur_eden_size) {
duke@435 363 to_start = from_end;
duke@435 364 if (to_start + requested_survivor_size > to_start) {
duke@435 365 to_end = to_start + requested_survivor_size;
duke@435 366 }
duke@435 367 }
duke@435 368 // else leave to_end pointing to the high end of the virtual space.
duke@435 369 }
duke@435 370
duke@435 371 guarantee(to_start != to_end, "to space is zero sized");
duke@435 372
duke@435 373 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 374 gclog_or_tty->print_cr(" [eden_start .. eden_end): "
duke@435 375 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 376 eden_start,
duke@435 377 eden_end,
duke@435 378 pointer_delta(eden_end, eden_start, sizeof(char)));
duke@435 379 gclog_or_tty->print_cr(" [from_start .. from_end): "
duke@435 380 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 381 from_start,
duke@435 382 from_end,
duke@435 383 pointer_delta(from_end, from_start, sizeof(char)));
duke@435 384 gclog_or_tty->print_cr(" [ to_start .. to_end): "
duke@435 385 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 386 to_start,
duke@435 387 to_end,
duke@435 388 pointer_delta( to_end, to_start, sizeof(char)));
duke@435 389 }
duke@435 390 } else {
duke@435 391 // Eden, to, from
duke@435 392 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 393 gclog_or_tty->print_cr(" Eden, to, from:");
duke@435 394 }
duke@435 395
duke@435 396 // Calculate the to-space boundaries based on
duke@435 397 // the start of from-space.
duke@435 398 to_end = from_start;
duke@435 399 to_start = (char*)pointer_delta(from_start,
duke@435 400 (char*)requested_survivor_size,
duke@435 401 sizeof(char));
duke@435 402 // Calculate the ideal eden boundaries.
duke@435 403 // eden_end is already at the bottom of the generation
duke@435 404 assert(eden_start == virtual_space()->low(),
duke@435 405 "Eden is not starting at the low end of the virtual space");
duke@435 406 if (eden_start + requested_eden_size >= eden_start) {
duke@435 407 eden_end = eden_start + requested_eden_size;
duke@435 408 } else {
duke@435 409 eden_end = to_start;
duke@435 410 }
duke@435 411
duke@435 412 // Does eden intrude into to-space? to-space
duke@435 413 // gets priority but eden is not allowed to shrink
duke@435 414 // to 0.
duke@435 415 if (eden_end > to_start) {
duke@435 416 eden_end = to_start;
duke@435 417 }
duke@435 418
duke@435 419 // Don't let eden shrink down to 0 or less.
duke@435 420 eden_end = MAX2(eden_end, eden_start + alignment);
duke@435 421 assert(eden_start + alignment >= eden_start, "Overflow");
duke@435 422
duke@435 423 size_t eden_size;
duke@435 424 if (maintain_minimum) {
duke@435 425 // Use all the space available.
duke@435 426 eden_end = MAX2(eden_end, to_start);
duke@435 427 eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
duke@435 428 eden_size = MIN2(eden_size, cur_eden_size);
duke@435 429 } else {
duke@435 430 eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
duke@435 431 }
duke@435 432 eden_size = align_size_down(eden_size, alignment);
duke@435 433 assert(maintain_minimum || eden_size <= requested_eden_size,
duke@435 434 "Eden size is too large");
duke@435 435 assert(eden_size >= alignment, "Eden size is too small");
duke@435 436 eden_end = eden_start + eden_size;
duke@435 437
duke@435 438 // Move to-space down to eden.
duke@435 439 if (requested_eden_size < cur_eden_size) {
duke@435 440 to_start = eden_end;
duke@435 441 if (to_start + requested_survivor_size > to_start) {
duke@435 442 to_end = MIN2(from_start, to_start + requested_survivor_size);
duke@435 443 } else {
duke@435 444 to_end = from_start;
duke@435 445 }
duke@435 446 }
duke@435 447
duke@435 448 // eden_end may have moved so again make sure
duke@435 449 // the to-space and eden don't overlap.
duke@435 450 to_start = MAX2(eden_end, to_start);
duke@435 451
duke@435 452 // from-space
duke@435 453 size_t from_used = from()->used();
duke@435 454 if (requested_survivor_size > from_used) {
duke@435 455 if (from_start + requested_survivor_size >= from_start) {
duke@435 456 from_end = from_start + requested_survivor_size;
duke@435 457 }
duke@435 458 if (from_end > virtual_space()->high()) {
duke@435 459 from_end = virtual_space()->high();
duke@435 460 }
duke@435 461 }
duke@435 462
duke@435 463 assert(to_start >= eden_end, "to-space should be above eden");
duke@435 464 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 465 gclog_or_tty->print_cr(" [eden_start .. eden_end): "
duke@435 466 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 467 eden_start,
duke@435 468 eden_end,
duke@435 469 pointer_delta(eden_end, eden_start, sizeof(char)));
duke@435 470 gclog_or_tty->print_cr(" [ to_start .. to_end): "
duke@435 471 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 472 to_start,
duke@435 473 to_end,
duke@435 474 pointer_delta( to_end, to_start, sizeof(char)));
duke@435 475 gclog_or_tty->print_cr(" [from_start .. from_end): "
duke@435 476 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 477 from_start,
duke@435 478 from_end,
duke@435 479 pointer_delta(from_end, from_start, sizeof(char)));
duke@435 480 }
duke@435 481 }
duke@435 482
duke@435 483
duke@435 484 guarantee((HeapWord*)from_start <= from()->bottom(),
duke@435 485 "from start moved to the right");
duke@435 486 guarantee((HeapWord*)from_end >= from()->top(),
duke@435 487 "from end moved into live data");
duke@435 488 assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
duke@435 489 assert(is_object_aligned((intptr_t)from_start), "checking alignment");
duke@435 490 assert(is_object_aligned((intptr_t)to_start), "checking alignment");
duke@435 491
duke@435 492 MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
duke@435 493 MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end);
duke@435 494 MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
duke@435 495
duke@435 496 // Let's make sure the call to initialize doesn't reset "top"!
duke@435 497 HeapWord* old_from_top = from()->top();
duke@435 498
duke@435 499 // For PrintAdaptiveSizePolicy block below
duke@435 500 size_t old_from = from()->capacity();
duke@435 501 size_t old_to = to()->capacity();
duke@435 502
jmasa@698 503 // If not clearing the spaces, do some checking to verify that
jmasa@698 504 // the spaces are already mangled.
jmasa@698 505
jmasa@698 506 // Must check mangling before the spaces are reshaped. Otherwise,
jmasa@698 507 // the bottom or end of one space may have moved into another
jmasa@698 508 // a failure of the check may not correctly indicate which space
jmasa@698 509 // is not properly mangled.
jmasa@698 510 if (ZapUnusedHeapArea) {
jmasa@698 511 HeapWord* limit = (HeapWord*) virtual_space()->high();
jmasa@698 512 eden()->check_mangled_unused_area(limit);
jmasa@698 513 from()->check_mangled_unused_area(limit);
jmasa@698 514 to()->check_mangled_unused_area(limit);
jmasa@698 515 }
jmasa@698 516
duke@435 517 // The call to initialize NULL's the next compaction space
jmasa@698 518 eden()->initialize(edenMR,
jmasa@698 519 SpaceDecorator::Clear,
jmasa@698 520 SpaceDecorator::DontMangle);
duke@435 521 eden()->set_next_compaction_space(from());
jmasa@698 522 to()->initialize(toMR ,
jmasa@698 523 SpaceDecorator::Clear,
jmasa@698 524 SpaceDecorator::DontMangle);
jmasa@698 525 from()->initialize(fromMR,
jmasa@698 526 SpaceDecorator::DontClear,
jmasa@698 527 SpaceDecorator::DontMangle);
duke@435 528
duke@435 529 assert(from()->top() == old_from_top, "from top changed!");
duke@435 530
duke@435 531 if (PrintAdaptiveSizePolicy) {
duke@435 532 GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435 533 assert(gch->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
duke@435 534
duke@435 535 gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
duke@435 536 "collection: %d "
duke@435 537 "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
duke@435 538 "(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
duke@435 539 gch->total_collections(),
duke@435 540 old_from, old_to,
duke@435 541 from()->capacity(),
duke@435 542 to()->capacity());
duke@435 543 gclog_or_tty->cr();
duke@435 544 }
duke@435 545 }
duke@435 546
duke@435 547 void ASParNewGeneration::compute_new_size() {
duke@435 548 GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435 549 assert(gch->kind() == CollectedHeap::GenCollectedHeap,
duke@435 550 "not a CMS generational heap");
duke@435 551
duke@435 552
duke@435 553 CMSAdaptiveSizePolicy* size_policy =
duke@435 554 (CMSAdaptiveSizePolicy*)gch->gen_policy()->size_policy();
duke@435 555 assert(size_policy->is_gc_cms_adaptive_size_policy(),
duke@435 556 "Wrong type of size policy");
duke@435 557
duke@435 558 size_t survived = from()->used();
duke@435 559 if (!survivor_overflow()) {
duke@435 560 // Keep running averages on how much survived
duke@435 561 size_policy->avg_survived()->sample(survived);
duke@435 562 } else {
duke@435 563 size_t promoted =
duke@435 564 (size_t) next_gen()->gc_stats()->avg_promoted()->last_sample();
duke@435 565 assert(promoted < gch->capacity(), "Conversion problem?");
duke@435 566 size_t survived_guess = survived + promoted;
duke@435 567 size_policy->avg_survived()->sample(survived_guess);
duke@435 568 }
duke@435 569
duke@435 570 size_t survivor_limit = max_survivor_size();
duke@435 571 _tenuring_threshold =
duke@435 572 size_policy->compute_survivor_space_size_and_threshold(
duke@435 573 _survivor_overflow,
duke@435 574 _tenuring_threshold,
duke@435 575 survivor_limit);
duke@435 576 size_policy->avg_young_live()->sample(used());
duke@435 577 size_policy->avg_eden_live()->sample(eden()->used());
duke@435 578
duke@435 579 size_policy->compute_young_generation_free_space(eden()->capacity(),
duke@435 580 max_gen_size());
duke@435 581
duke@435 582 resize(size_policy->calculated_eden_size_in_bytes(),
duke@435 583 size_policy->calculated_survivor_size_in_bytes());
duke@435 584
duke@435 585 if (UsePerfData) {
duke@435 586 CMSGCAdaptivePolicyCounters* counters =
duke@435 587 (CMSGCAdaptivePolicyCounters*) gch->collector_policy()->counters();
duke@435 588 assert(counters->kind() ==
duke@435 589 GCPolicyCounters::CMSGCAdaptivePolicyCountersKind,
duke@435 590 "Wrong kind of counters");
duke@435 591 counters->update_tenuring_threshold(_tenuring_threshold);
duke@435 592 counters->update_survivor_overflowed(_survivor_overflow);
duke@435 593 counters->update_young_capacity(capacity());
duke@435 594 }
duke@435 595 }
duke@435 596
duke@435 597
duke@435 598 #ifndef PRODUCT
duke@435 599 // Changes from PSYoungGen version
duke@435 600 // value of "alignment"
duke@435 601 void ASParNewGeneration::space_invariants() {
duke@435 602 const size_t alignment = os::vm_page_size();
duke@435 603
duke@435 604 // Currently, our eden size cannot shrink to zero
duke@435 605 guarantee(eden()->capacity() >= alignment, "eden too small");
duke@435 606 guarantee(from()->capacity() >= alignment, "from too small");
duke@435 607 guarantee(to()->capacity() >= alignment, "to too small");
duke@435 608
duke@435 609 // Relationship of spaces to each other
duke@435 610 char* eden_start = (char*)eden()->bottom();
duke@435 611 char* eden_end = (char*)eden()->end();
duke@435 612 char* from_start = (char*)from()->bottom();
duke@435 613 char* from_end = (char*)from()->end();
duke@435 614 char* to_start = (char*)to()->bottom();
duke@435 615 char* to_end = (char*)to()->end();
duke@435 616
duke@435 617 guarantee(eden_start >= virtual_space()->low(), "eden bottom");
duke@435 618 guarantee(eden_start < eden_end, "eden space consistency");
duke@435 619 guarantee(from_start < from_end, "from space consistency");
duke@435 620 guarantee(to_start < to_end, "to space consistency");
duke@435 621
duke@435 622 // Check whether from space is below to space
duke@435 623 if (from_start < to_start) {
duke@435 624 // Eden, from, to
duke@435 625 guarantee(eden_end <= from_start, "eden/from boundary");
duke@435 626 guarantee(from_end <= to_start, "from/to boundary");
duke@435 627 guarantee(to_end <= virtual_space()->high(), "to end");
duke@435 628 } else {
duke@435 629 // Eden, to, from
duke@435 630 guarantee(eden_end <= to_start, "eden/to boundary");
duke@435 631 guarantee(to_end <= from_start, "to/from boundary");
duke@435 632 guarantee(from_end <= virtual_space()->high(), "from end");
duke@435 633 }
duke@435 634
duke@435 635 // More checks that the virtual space is consistent with the spaces
duke@435 636 assert(virtual_space()->committed_size() >=
duke@435 637 (eden()->capacity() +
duke@435 638 to()->capacity() +
duke@435 639 from()->capacity()), "Committed size is inconsistent");
duke@435 640 assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
duke@435 641 "Space invariant");
duke@435 642 char* eden_top = (char*)eden()->top();
duke@435 643 char* from_top = (char*)from()->top();
duke@435 644 char* to_top = (char*)to()->top();
duke@435 645 assert(eden_top <= virtual_space()->high(), "eden top");
duke@435 646 assert(from_top <= virtual_space()->high(), "from top");
duke@435 647 assert(to_top <= virtual_space()->high(), "to top");
duke@435 648 }
duke@435 649 #endif

mercurial