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

Wed, 28 May 2008 21:06:24 -0700

author
coleenp
date
Wed, 28 May 2008 21:06:24 -0700
changeset 602
feeb96a45707
parent 448
183f41cf8bfe
child 631
d1605aabd0a1
child 698
12eea04c8b06
permissions
-rw-r--r--

6696264: assert("narrow oop can never be zero") for GCBasher & ParNewGC
Summary: decouple set_klass() with zeroing the gap when compressed.
Reviewed-by: kvn, ysr, jrose

duke@435 1 /*
duke@435 2 * Copyright 2005-2006 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");
duke@435 165 if (!virtual_space()->expand_by(change)) {
duke@435 166 return false; // Error if we fail to resize!
duke@435 167 }
duke@435 168
duke@435 169 size_changed = true;
duke@435 170 } else if (desired_size < orig_size) {
duke@435 171 size_t desired_change = orig_size - desired_size;
duke@435 172 assert(desired_change % alignment == 0, "just checking");
duke@435 173
duke@435 174 desired_change = limit_gen_shrink(desired_change);
duke@435 175
duke@435 176 if (desired_change > 0) {
duke@435 177 virtual_space()->shrink_by(desired_change);
duke@435 178 reset_survivors_after_shrink();
duke@435 179
duke@435 180 size_changed = true;
duke@435 181 }
duke@435 182 } else {
duke@435 183 if (Verbose && PrintGC) {
duke@435 184 if (orig_size == max_gen_size()) {
duke@435 185 gclog_or_tty->print_cr("ASParNew generation size at maximum: "
duke@435 186 SIZE_FORMAT "K", orig_size/K);
duke@435 187 } else if (orig_size == min_gen_size()) {
duke@435 188 gclog_or_tty->print_cr("ASParNew generation size at minium: "
duke@435 189 SIZE_FORMAT "K", orig_size/K);
duke@435 190 }
duke@435 191 }
duke@435 192 }
duke@435 193
duke@435 194 if (size_changed) {
duke@435 195 MemRegion cmr((HeapWord*)virtual_space()->low(),
duke@435 196 (HeapWord*)virtual_space()->high());
duke@435 197 GenCollectedHeap::heap()->barrier_set()->resize_covered_region(cmr);
duke@435 198
duke@435 199 if (Verbose && PrintGC) {
duke@435 200 size_t current_size = virtual_space()->committed_size();
duke@435 201 gclog_or_tty->print_cr("ASParNew generation size changed: "
duke@435 202 SIZE_FORMAT "K->" SIZE_FORMAT "K",
duke@435 203 orig_size/K, current_size/K);
duke@435 204 }
duke@435 205 }
duke@435 206
duke@435 207 guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
duke@435 208 virtual_space()->committed_size() == max_gen_size(), "Sanity");
duke@435 209
duke@435 210 return true;
duke@435 211 }
duke@435 212
duke@435 213 void ASParNewGeneration::reset_survivors_after_shrink() {
duke@435 214
duke@435 215 GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435 216 HeapWord* new_end = (HeapWord*)virtual_space()->high();
duke@435 217
duke@435 218 if (from()->end() > to()->end()) {
duke@435 219 assert(new_end >= from()->end(), "Shrinking past from-space");
duke@435 220 } else {
duke@435 221 assert(new_end >= to()->bottom(), "Shrink was too large");
duke@435 222 // Was there a shrink of the survivor space?
duke@435 223 if (new_end < to()->end()) {
duke@435 224 MemRegion mr(to()->bottom(), new_end);
duke@435 225 to()->initialize(mr, false /* clear */);
duke@435 226 }
duke@435 227 }
duke@435 228 }
duke@435 229 void ASParNewGeneration::resize_spaces(size_t requested_eden_size,
duke@435 230 size_t requested_survivor_size) {
duke@435 231 assert(UseAdaptiveSizePolicy, "sanity check");
duke@435 232 assert(requested_eden_size > 0 && requested_survivor_size > 0,
duke@435 233 "just checking");
duke@435 234 CollectedHeap* heap = Universe::heap();
duke@435 235 assert(heap->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
duke@435 236
duke@435 237
duke@435 238 // We require eden and to space to be empty
duke@435 239 if ((!eden()->is_empty()) || (!to()->is_empty())) {
duke@435 240 return;
duke@435 241 }
duke@435 242
duke@435 243 size_t cur_eden_size = eden()->capacity();
duke@435 244
duke@435 245 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 246 gclog_or_tty->print_cr("ASParNew::resize_spaces(requested_eden_size: "
duke@435 247 SIZE_FORMAT
duke@435 248 ", requested_survivor_size: " SIZE_FORMAT ")",
duke@435 249 requested_eden_size, requested_survivor_size);
duke@435 250 gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435 251 SIZE_FORMAT,
duke@435 252 eden()->bottom(),
duke@435 253 eden()->end(),
duke@435 254 pointer_delta(eden()->end(),
duke@435 255 eden()->bottom(),
duke@435 256 sizeof(char)));
duke@435 257 gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435 258 SIZE_FORMAT,
duke@435 259 from()->bottom(),
duke@435 260 from()->end(),
duke@435 261 pointer_delta(from()->end(),
duke@435 262 from()->bottom(),
duke@435 263 sizeof(char)));
duke@435 264 gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435 265 SIZE_FORMAT,
duke@435 266 to()->bottom(),
duke@435 267 to()->end(),
duke@435 268 pointer_delta( to()->end(),
duke@435 269 to()->bottom(),
duke@435 270 sizeof(char)));
duke@435 271 }
duke@435 272
duke@435 273 // There's nothing to do if the new sizes are the same as the current
duke@435 274 if (requested_survivor_size == to()->capacity() &&
duke@435 275 requested_survivor_size == from()->capacity() &&
duke@435 276 requested_eden_size == eden()->capacity()) {
duke@435 277 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 278 gclog_or_tty->print_cr(" capacities are the right sizes, returning");
duke@435 279 }
duke@435 280 return;
duke@435 281 }
duke@435 282
duke@435 283 char* eden_start = (char*)eden()->bottom();
duke@435 284 char* eden_end = (char*)eden()->end();
duke@435 285 char* from_start = (char*)from()->bottom();
duke@435 286 char* from_end = (char*)from()->end();
duke@435 287 char* to_start = (char*)to()->bottom();
duke@435 288 char* to_end = (char*)to()->end();
duke@435 289
duke@435 290 const size_t alignment = os::vm_page_size();
duke@435 291 const bool maintain_minimum =
duke@435 292 (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
duke@435 293
duke@435 294 // Check whether from space is below to space
duke@435 295 if (from_start < to_start) {
duke@435 296 // Eden, from, to
duke@435 297 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 298 gclog_or_tty->print_cr(" Eden, from, to:");
duke@435 299 }
duke@435 300
duke@435 301 // Set eden
duke@435 302 // "requested_eden_size" is a goal for the size of eden
duke@435 303 // and may not be attainable. "eden_size" below is
duke@435 304 // calculated based on the location of from-space and
duke@435 305 // the goal for the size of eden. from-space is
duke@435 306 // fixed in place because it contains live data.
duke@435 307 // The calculation is done this way to avoid 32bit
duke@435 308 // overflow (i.e., eden_start + requested_eden_size
duke@435 309 // may too large for representation in 32bits).
duke@435 310 size_t eden_size;
duke@435 311 if (maintain_minimum) {
duke@435 312 // Only make eden larger than the requested size if
duke@435 313 // the minimum size of the generation has to be maintained.
duke@435 314 // This could be done in general but policy at a higher
duke@435 315 // level is determining a requested size for eden and that
duke@435 316 // should be honored unless there is a fundamental reason.
duke@435 317 eden_size = pointer_delta(from_start,
duke@435 318 eden_start,
duke@435 319 sizeof(char));
duke@435 320 } else {
duke@435 321 eden_size = MIN2(requested_eden_size,
duke@435 322 pointer_delta(from_start, eden_start, sizeof(char)));
duke@435 323 }
duke@435 324
duke@435 325 // tty->print_cr("eden_size before: " SIZE_FORMAT, eden_size);
duke@435 326 eden_size = align_size_down(eden_size, alignment);
duke@435 327 // tty->print_cr("eden_size after: " SIZE_FORMAT, eden_size);
duke@435 328 eden_end = eden_start + eden_size;
duke@435 329 assert(eden_end >= eden_start, "addition overflowed")
duke@435 330
duke@435 331 // To may resize into from space as long as it is clear of live data.
duke@435 332 // From space must remain page aligned, though, so we need to do some
duke@435 333 // extra calculations.
duke@435 334
duke@435 335 // First calculate an optimal to-space
duke@435 336 to_end = (char*)virtual_space()->high();
duke@435 337 to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
duke@435 338 sizeof(char));
duke@435 339
duke@435 340 // Does the optimal to-space overlap from-space?
duke@435 341 if (to_start < (char*)from()->end()) {
duke@435 342 // Calculate the minimum offset possible for from_end
duke@435 343 size_t from_size = pointer_delta(from()->top(), from_start, sizeof(char));
duke@435 344
duke@435 345 // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
duke@435 346 if (from_size == 0) {
duke@435 347 from_size = alignment;
duke@435 348 } else {
duke@435 349 from_size = align_size_up(from_size, alignment);
duke@435 350 }
duke@435 351
duke@435 352 from_end = from_start + from_size;
duke@435 353 assert(from_end > from_start, "addition overflow or from_size problem");
duke@435 354
duke@435 355 guarantee(from_end <= (char*)from()->end(), "from_end moved to the right");
duke@435 356
duke@435 357 // Now update to_start with the new from_end
duke@435 358 to_start = MAX2(from_end, to_start);
duke@435 359 } else {
duke@435 360 // If shrinking, move to-space down to abut the end of from-space
duke@435 361 // so that shrinking will move to-space down. If not shrinking
duke@435 362 // to-space is moving up to allow for growth on the next expansion.
duke@435 363 if (requested_eden_size <= cur_eden_size) {
duke@435 364 to_start = from_end;
duke@435 365 if (to_start + requested_survivor_size > to_start) {
duke@435 366 to_end = to_start + requested_survivor_size;
duke@435 367 }
duke@435 368 }
duke@435 369 // else leave to_end pointing to the high end of the virtual space.
duke@435 370 }
duke@435 371
duke@435 372 guarantee(to_start != to_end, "to space is zero sized");
duke@435 373
duke@435 374 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 375 gclog_or_tty->print_cr(" [eden_start .. eden_end): "
duke@435 376 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 377 eden_start,
duke@435 378 eden_end,
duke@435 379 pointer_delta(eden_end, eden_start, sizeof(char)));
duke@435 380 gclog_or_tty->print_cr(" [from_start .. from_end): "
duke@435 381 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 382 from_start,
duke@435 383 from_end,
duke@435 384 pointer_delta(from_end, from_start, sizeof(char)));
duke@435 385 gclog_or_tty->print_cr(" [ to_start .. to_end): "
duke@435 386 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 387 to_start,
duke@435 388 to_end,
duke@435 389 pointer_delta( to_end, to_start, sizeof(char)));
duke@435 390 }
duke@435 391 } else {
duke@435 392 // Eden, to, from
duke@435 393 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 394 gclog_or_tty->print_cr(" Eden, to, from:");
duke@435 395 }
duke@435 396
duke@435 397 // Calculate the to-space boundaries based on
duke@435 398 // the start of from-space.
duke@435 399 to_end = from_start;
duke@435 400 to_start = (char*)pointer_delta(from_start,
duke@435 401 (char*)requested_survivor_size,
duke@435 402 sizeof(char));
duke@435 403 // Calculate the ideal eden boundaries.
duke@435 404 // eden_end is already at the bottom of the generation
duke@435 405 assert(eden_start == virtual_space()->low(),
duke@435 406 "Eden is not starting at the low end of the virtual space");
duke@435 407 if (eden_start + requested_eden_size >= eden_start) {
duke@435 408 eden_end = eden_start + requested_eden_size;
duke@435 409 } else {
duke@435 410 eden_end = to_start;
duke@435 411 }
duke@435 412
duke@435 413 // Does eden intrude into to-space? to-space
duke@435 414 // gets priority but eden is not allowed to shrink
duke@435 415 // to 0.
duke@435 416 if (eden_end > to_start) {
duke@435 417 eden_end = to_start;
duke@435 418 }
duke@435 419
duke@435 420 // Don't let eden shrink down to 0 or less.
duke@435 421 eden_end = MAX2(eden_end, eden_start + alignment);
duke@435 422 assert(eden_start + alignment >= eden_start, "Overflow");
duke@435 423
duke@435 424 size_t eden_size;
duke@435 425 if (maintain_minimum) {
duke@435 426 // Use all the space available.
duke@435 427 eden_end = MAX2(eden_end, to_start);
duke@435 428 eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
duke@435 429 eden_size = MIN2(eden_size, cur_eden_size);
duke@435 430 } else {
duke@435 431 eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
duke@435 432 }
duke@435 433 eden_size = align_size_down(eden_size, alignment);
duke@435 434 assert(maintain_minimum || eden_size <= requested_eden_size,
duke@435 435 "Eden size is too large");
duke@435 436 assert(eden_size >= alignment, "Eden size is too small");
duke@435 437 eden_end = eden_start + eden_size;
duke@435 438
duke@435 439 // Move to-space down to eden.
duke@435 440 if (requested_eden_size < cur_eden_size) {
duke@435 441 to_start = eden_end;
duke@435 442 if (to_start + requested_survivor_size > to_start) {
duke@435 443 to_end = MIN2(from_start, to_start + requested_survivor_size);
duke@435 444 } else {
duke@435 445 to_end = from_start;
duke@435 446 }
duke@435 447 }
duke@435 448
duke@435 449 // eden_end may have moved so again make sure
duke@435 450 // the to-space and eden don't overlap.
duke@435 451 to_start = MAX2(eden_end, to_start);
duke@435 452
duke@435 453 // from-space
duke@435 454 size_t from_used = from()->used();
duke@435 455 if (requested_survivor_size > from_used) {
duke@435 456 if (from_start + requested_survivor_size >= from_start) {
duke@435 457 from_end = from_start + requested_survivor_size;
duke@435 458 }
duke@435 459 if (from_end > virtual_space()->high()) {
duke@435 460 from_end = virtual_space()->high();
duke@435 461 }
duke@435 462 }
duke@435 463
duke@435 464 assert(to_start >= eden_end, "to-space should be above eden");
duke@435 465 if (PrintAdaptiveSizePolicy && Verbose) {
duke@435 466 gclog_or_tty->print_cr(" [eden_start .. eden_end): "
duke@435 467 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 468 eden_start,
duke@435 469 eden_end,
duke@435 470 pointer_delta(eden_end, eden_start, sizeof(char)));
duke@435 471 gclog_or_tty->print_cr(" [ to_start .. to_end): "
duke@435 472 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 473 to_start,
duke@435 474 to_end,
duke@435 475 pointer_delta( to_end, to_start, sizeof(char)));
duke@435 476 gclog_or_tty->print_cr(" [from_start .. from_end): "
duke@435 477 "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
duke@435 478 from_start,
duke@435 479 from_end,
duke@435 480 pointer_delta(from_end, from_start, sizeof(char)));
duke@435 481 }
duke@435 482 }
duke@435 483
duke@435 484
duke@435 485 guarantee((HeapWord*)from_start <= from()->bottom(),
duke@435 486 "from start moved to the right");
duke@435 487 guarantee((HeapWord*)from_end >= from()->top(),
duke@435 488 "from end moved into live data");
duke@435 489 assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
duke@435 490 assert(is_object_aligned((intptr_t)from_start), "checking alignment");
duke@435 491 assert(is_object_aligned((intptr_t)to_start), "checking alignment");
duke@435 492
duke@435 493 MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
duke@435 494 MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end);
duke@435 495 MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
duke@435 496
duke@435 497 // Let's make sure the call to initialize doesn't reset "top"!
duke@435 498 HeapWord* old_from_top = from()->top();
duke@435 499
duke@435 500 // For PrintAdaptiveSizePolicy block below
duke@435 501 size_t old_from = from()->capacity();
duke@435 502 size_t old_to = to()->capacity();
duke@435 503
duke@435 504 // The call to initialize NULL's the next compaction space
duke@435 505 eden()->initialize(edenMR, true);
duke@435 506 eden()->set_next_compaction_space(from());
duke@435 507 to()->initialize(toMR , true);
duke@435 508 from()->initialize(fromMR, false); // Note, not cleared!
duke@435 509
duke@435 510 assert(from()->top() == old_from_top, "from top changed!");
duke@435 511
duke@435 512 if (PrintAdaptiveSizePolicy) {
duke@435 513 GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435 514 assert(gch->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
duke@435 515
duke@435 516 gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
duke@435 517 "collection: %d "
duke@435 518 "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
duke@435 519 "(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
duke@435 520 gch->total_collections(),
duke@435 521 old_from, old_to,
duke@435 522 from()->capacity(),
duke@435 523 to()->capacity());
duke@435 524 gclog_or_tty->cr();
duke@435 525 }
duke@435 526 }
duke@435 527
duke@435 528 void ASParNewGeneration::compute_new_size() {
duke@435 529 GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435 530 assert(gch->kind() == CollectedHeap::GenCollectedHeap,
duke@435 531 "not a CMS generational heap");
duke@435 532
duke@435 533
duke@435 534 CMSAdaptiveSizePolicy* size_policy =
duke@435 535 (CMSAdaptiveSizePolicy*)gch->gen_policy()->size_policy();
duke@435 536 assert(size_policy->is_gc_cms_adaptive_size_policy(),
duke@435 537 "Wrong type of size policy");
duke@435 538
duke@435 539 size_t survived = from()->used();
duke@435 540 if (!survivor_overflow()) {
duke@435 541 // Keep running averages on how much survived
duke@435 542 size_policy->avg_survived()->sample(survived);
duke@435 543 } else {
duke@435 544 size_t promoted =
duke@435 545 (size_t) next_gen()->gc_stats()->avg_promoted()->last_sample();
duke@435 546 assert(promoted < gch->capacity(), "Conversion problem?");
duke@435 547 size_t survived_guess = survived + promoted;
duke@435 548 size_policy->avg_survived()->sample(survived_guess);
duke@435 549 }
duke@435 550
duke@435 551 size_t survivor_limit = max_survivor_size();
duke@435 552 _tenuring_threshold =
duke@435 553 size_policy->compute_survivor_space_size_and_threshold(
duke@435 554 _survivor_overflow,
duke@435 555 _tenuring_threshold,
duke@435 556 survivor_limit);
duke@435 557 size_policy->avg_young_live()->sample(used());
duke@435 558 size_policy->avg_eden_live()->sample(eden()->used());
duke@435 559
duke@435 560 size_policy->compute_young_generation_free_space(eden()->capacity(),
duke@435 561 max_gen_size());
duke@435 562
duke@435 563 resize(size_policy->calculated_eden_size_in_bytes(),
duke@435 564 size_policy->calculated_survivor_size_in_bytes());
duke@435 565
duke@435 566 if (UsePerfData) {
duke@435 567 CMSGCAdaptivePolicyCounters* counters =
duke@435 568 (CMSGCAdaptivePolicyCounters*) gch->collector_policy()->counters();
duke@435 569 assert(counters->kind() ==
duke@435 570 GCPolicyCounters::CMSGCAdaptivePolicyCountersKind,
duke@435 571 "Wrong kind of counters");
duke@435 572 counters->update_tenuring_threshold(_tenuring_threshold);
duke@435 573 counters->update_survivor_overflowed(_survivor_overflow);
duke@435 574 counters->update_young_capacity(capacity());
duke@435 575 }
duke@435 576 }
duke@435 577
duke@435 578
duke@435 579 #ifndef PRODUCT
duke@435 580 // Changes from PSYoungGen version
duke@435 581 // value of "alignment"
duke@435 582 void ASParNewGeneration::space_invariants() {
duke@435 583 const size_t alignment = os::vm_page_size();
duke@435 584
duke@435 585 // Currently, our eden size cannot shrink to zero
duke@435 586 guarantee(eden()->capacity() >= alignment, "eden too small");
duke@435 587 guarantee(from()->capacity() >= alignment, "from too small");
duke@435 588 guarantee(to()->capacity() >= alignment, "to too small");
duke@435 589
duke@435 590 // Relationship of spaces to each other
duke@435 591 char* eden_start = (char*)eden()->bottom();
duke@435 592 char* eden_end = (char*)eden()->end();
duke@435 593 char* from_start = (char*)from()->bottom();
duke@435 594 char* from_end = (char*)from()->end();
duke@435 595 char* to_start = (char*)to()->bottom();
duke@435 596 char* to_end = (char*)to()->end();
duke@435 597
duke@435 598 guarantee(eden_start >= virtual_space()->low(), "eden bottom");
duke@435 599 guarantee(eden_start < eden_end, "eden space consistency");
duke@435 600 guarantee(from_start < from_end, "from space consistency");
duke@435 601 guarantee(to_start < to_end, "to space consistency");
duke@435 602
duke@435 603 // Check whether from space is below to space
duke@435 604 if (from_start < to_start) {
duke@435 605 // Eden, from, to
duke@435 606 guarantee(eden_end <= from_start, "eden/from boundary");
duke@435 607 guarantee(from_end <= to_start, "from/to boundary");
duke@435 608 guarantee(to_end <= virtual_space()->high(), "to end");
duke@435 609 } else {
duke@435 610 // Eden, to, from
duke@435 611 guarantee(eden_end <= to_start, "eden/to boundary");
duke@435 612 guarantee(to_end <= from_start, "to/from boundary");
duke@435 613 guarantee(from_end <= virtual_space()->high(), "from end");
duke@435 614 }
duke@435 615
duke@435 616 // More checks that the virtual space is consistent with the spaces
duke@435 617 assert(virtual_space()->committed_size() >=
duke@435 618 (eden()->capacity() +
duke@435 619 to()->capacity() +
duke@435 620 from()->capacity()), "Committed size is inconsistent");
duke@435 621 assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
duke@435 622 "Space invariant");
duke@435 623 char* eden_top = (char*)eden()->top();
duke@435 624 char* from_top = (char*)from()->top();
duke@435 625 char* to_top = (char*)to()->top();
duke@435 626 assert(eden_top <= virtual_space()->high(), "eden top");
duke@435 627 assert(from_top <= virtual_space()->high(), "from top");
duke@435 628 assert(to_top <= virtual_space()->high(), "to top");
duke@435 629 }
duke@435 630 #endif

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