1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parNew/asParNewGeneration.cpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,657 @@
1.4 +/*
1.5 + * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#include "precompiled.hpp"
1.29 +#include "gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp"
1.30 +#include "gc_implementation/concurrentMarkSweep/cmsGCAdaptivePolicyCounters.hpp"
1.31 +#include "gc_implementation/parNew/asParNewGeneration.hpp"
1.32 +#include "gc_implementation/parNew/parNewGeneration.hpp"
1.33 +#include "gc_implementation/shared/markSweep.inline.hpp"
1.34 +#include "gc_implementation/shared/spaceDecorator.hpp"
1.35 +#include "memory/defNewGeneration.inline.hpp"
1.36 +#include "memory/referencePolicy.hpp"
1.37 +#include "oops/markOop.inline.hpp"
1.38 +#include "oops/oop.pcgc.inline.hpp"
1.39 +
1.40 +ASParNewGeneration::ASParNewGeneration(ReservedSpace rs,
1.41 + size_t initial_byte_size,
1.42 + size_t min_byte_size,
1.43 + int level) :
1.44 + ParNewGeneration(rs, initial_byte_size, level),
1.45 + _min_gen_size(min_byte_size) {}
1.46 +
1.47 +const char* ASParNewGeneration::name() const {
1.48 + return "adaptive size par new generation";
1.49 +}
1.50 +
1.51 +void ASParNewGeneration::adjust_desired_tenuring_threshold() {
1.52 + assert(UseAdaptiveSizePolicy,
1.53 + "Should only be used with UseAdaptiveSizePolicy");
1.54 +}
1.55 +
1.56 +void ASParNewGeneration::resize(size_t eden_size, size_t survivor_size) {
1.57 + // Resize the generation if needed. If the generation resize
1.58 + // reports false, do not attempt to resize the spaces.
1.59 + if (resize_generation(eden_size, survivor_size)) {
1.60 + // Then we lay out the spaces inside the generation
1.61 + resize_spaces(eden_size, survivor_size);
1.62 +
1.63 + space_invariants();
1.64 +
1.65 + if (PrintAdaptiveSizePolicy && Verbose) {
1.66 + gclog_or_tty->print_cr("Young generation size: "
1.67 + "desired eden: " SIZE_FORMAT " survivor: " SIZE_FORMAT
1.68 + " used: " SIZE_FORMAT " capacity: " SIZE_FORMAT
1.69 + " gen limits: " SIZE_FORMAT " / " SIZE_FORMAT,
1.70 + eden_size, survivor_size, used(), capacity(),
1.71 + max_gen_size(), min_gen_size());
1.72 + }
1.73 + }
1.74 +}
1.75 +
1.76 +size_t ASParNewGeneration::available_to_min_gen() {
1.77 + assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant");
1.78 + return virtual_space()->committed_size() - min_gen_size();
1.79 +}
1.80 +
1.81 +// This method assumes that from-space has live data and that
1.82 +// any shrinkage of the young gen is limited by location of
1.83 +// from-space.
1.84 +size_t ASParNewGeneration::available_to_live() const {
1.85 +#undef SHRINKS_AT_END_OF_EDEN
1.86 +#ifdef SHRINKS_AT_END_OF_EDEN
1.87 + size_t delta_in_survivor = 0;
1.88 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.89 + const size_t space_alignment = heap->intra_heap_alignment();
1.90 + const size_t gen_alignment = heap->object_heap_alignment();
1.91 +
1.92 + MutableSpace* space_shrinking = NULL;
1.93 + if (from_space()->end() > to_space()->end()) {
1.94 + space_shrinking = from_space();
1.95 + } else {
1.96 + space_shrinking = to_space();
1.97 + }
1.98 +
1.99 + // Include any space that is committed but not included in
1.100 + // the survivor spaces.
1.101 + assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(),
1.102 + "Survivor space beyond high end");
1.103 + size_t unused_committed = pointer_delta(virtual_space()->high(),
1.104 + space_shrinking->end(), sizeof(char));
1.105 +
1.106 + if (space_shrinking->is_empty()) {
1.107 + // Don't let the space shrink to 0
1.108 + assert(space_shrinking->capacity_in_bytes() >= space_alignment,
1.109 + "Space is too small");
1.110 + delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment;
1.111 + } else {
1.112 + delta_in_survivor = pointer_delta(space_shrinking->end(),
1.113 + space_shrinking->top(),
1.114 + sizeof(char));
1.115 + }
1.116 +
1.117 + size_t delta_in_bytes = unused_committed + delta_in_survivor;
1.118 + delta_in_bytes = align_size_down(delta_in_bytes, gen_alignment);
1.119 + return delta_in_bytes;
1.120 +#else
1.121 + // The only space available for shrinking is in to-space if it
1.122 + // is above from-space.
1.123 + if (to()->bottom() > from()->bottom()) {
1.124 + const size_t alignment = os::vm_page_size();
1.125 + if (to()->capacity() < alignment) {
1.126 + return 0;
1.127 + } else {
1.128 + return to()->capacity() - alignment;
1.129 + }
1.130 + } else {
1.131 + return 0;
1.132 + }
1.133 +#endif
1.134 +}
1.135 +
1.136 +// Return the number of bytes available for resizing down the young
1.137 +// generation. This is the minimum of
1.138 +// input "bytes"
1.139 +// bytes to the minimum young gen size
1.140 +// bytes to the size currently being used + some small extra
1.141 +size_t ASParNewGeneration::limit_gen_shrink (size_t bytes) {
1.142 + // Allow shrinkage into the current eden but keep eden large enough
1.143 + // to maintain the minimum young gen size
1.144 + bytes = MIN3(bytes, available_to_min_gen(), available_to_live());
1.145 + return align_size_down(bytes, os::vm_page_size());
1.146 +}
1.147 +
1.148 +// Note that the the alignment used is the OS page size as
1.149 +// opposed to an alignment associated with the virtual space
1.150 +// (as is done in the ASPSYoungGen/ASPSOldGen)
1.151 +bool ASParNewGeneration::resize_generation(size_t eden_size,
1.152 + size_t survivor_size) {
1.153 + const size_t alignment = os::vm_page_size();
1.154 + size_t orig_size = virtual_space()->committed_size();
1.155 + bool size_changed = false;
1.156 +
1.157 + // There used to be this guarantee there.
1.158 + // guarantee ((eden_size + 2*survivor_size) <= _max_gen_size, "incorrect input arguments");
1.159 + // Code below forces this requirement. In addition the desired eden
1.160 + // size and disired survivor sizes are desired goals and may
1.161 + // exceed the total generation size.
1.162 +
1.163 + assert(min_gen_size() <= orig_size && orig_size <= max_gen_size(),
1.164 + "just checking");
1.165 +
1.166 + // Adjust new generation size
1.167 + const size_t eden_plus_survivors =
1.168 + align_size_up(eden_size + 2 * survivor_size, alignment);
1.169 + size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_gen_size()),
1.170 + min_gen_size());
1.171 + assert(desired_size <= max_gen_size(), "just checking");
1.172 +
1.173 + if (desired_size > orig_size) {
1.174 + // Grow the generation
1.175 + size_t change = desired_size - orig_size;
1.176 + assert(change % alignment == 0, "just checking");
1.177 + if (expand(change)) {
1.178 + return false; // Error if we fail to resize!
1.179 + }
1.180 + size_changed = true;
1.181 + } else if (desired_size < orig_size) {
1.182 + size_t desired_change = orig_size - desired_size;
1.183 + assert(desired_change % alignment == 0, "just checking");
1.184 +
1.185 + desired_change = limit_gen_shrink(desired_change);
1.186 +
1.187 + if (desired_change > 0) {
1.188 + virtual_space()->shrink_by(desired_change);
1.189 + reset_survivors_after_shrink();
1.190 +
1.191 + size_changed = true;
1.192 + }
1.193 + } else {
1.194 + if (Verbose && PrintGC) {
1.195 + if (orig_size == max_gen_size()) {
1.196 + gclog_or_tty->print_cr("ASParNew generation size at maximum: "
1.197 + SIZE_FORMAT "K", orig_size/K);
1.198 + } else if (orig_size == min_gen_size()) {
1.199 + gclog_or_tty->print_cr("ASParNew generation size at minium: "
1.200 + SIZE_FORMAT "K", orig_size/K);
1.201 + }
1.202 + }
1.203 + }
1.204 +
1.205 + if (size_changed) {
1.206 + MemRegion cmr((HeapWord*)virtual_space()->low(),
1.207 + (HeapWord*)virtual_space()->high());
1.208 + GenCollectedHeap::heap()->barrier_set()->resize_covered_region(cmr);
1.209 +
1.210 + if (Verbose && PrintGC) {
1.211 + size_t current_size = virtual_space()->committed_size();
1.212 + gclog_or_tty->print_cr("ASParNew generation size changed: "
1.213 + SIZE_FORMAT "K->" SIZE_FORMAT "K",
1.214 + orig_size/K, current_size/K);
1.215 + }
1.216 + }
1.217 +
1.218 + guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
1.219 + virtual_space()->committed_size() == max_gen_size(), "Sanity");
1.220 +
1.221 + return true;
1.222 +}
1.223 +
1.224 +void ASParNewGeneration::reset_survivors_after_shrink() {
1.225 +
1.226 + GenCollectedHeap* gch = GenCollectedHeap::heap();
1.227 + HeapWord* new_end = (HeapWord*)virtual_space()->high();
1.228 +
1.229 + if (from()->end() > to()->end()) {
1.230 + assert(new_end >= from()->end(), "Shrinking past from-space");
1.231 + } else {
1.232 + assert(new_end >= to()->bottom(), "Shrink was too large");
1.233 + // Was there a shrink of the survivor space?
1.234 + if (new_end < to()->end()) {
1.235 + MemRegion mr(to()->bottom(), new_end);
1.236 + to()->initialize(mr,
1.237 + SpaceDecorator::DontClear,
1.238 + SpaceDecorator::DontMangle);
1.239 + }
1.240 + }
1.241 +}
1.242 +void ASParNewGeneration::resize_spaces(size_t requested_eden_size,
1.243 + size_t requested_survivor_size) {
1.244 + assert(UseAdaptiveSizePolicy, "sanity check");
1.245 + assert(requested_eden_size > 0 && requested_survivor_size > 0,
1.246 + "just checking");
1.247 + CollectedHeap* heap = Universe::heap();
1.248 + assert(heap->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
1.249 +
1.250 +
1.251 + // We require eden and to space to be empty
1.252 + if ((!eden()->is_empty()) || (!to()->is_empty())) {
1.253 + return;
1.254 + }
1.255 +
1.256 + size_t cur_eden_size = eden()->capacity();
1.257 +
1.258 + if (PrintAdaptiveSizePolicy && Verbose) {
1.259 + gclog_or_tty->print_cr("ASParNew::resize_spaces(requested_eden_size: "
1.260 + SIZE_FORMAT
1.261 + ", requested_survivor_size: " SIZE_FORMAT ")",
1.262 + requested_eden_size, requested_survivor_size);
1.263 + gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") "
1.264 + SIZE_FORMAT,
1.265 + p2i(eden()->bottom()),
1.266 + p2i(eden()->end()),
1.267 + pointer_delta(eden()->end(),
1.268 + eden()->bottom(),
1.269 + sizeof(char)));
1.270 + gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") "
1.271 + SIZE_FORMAT,
1.272 + p2i(from()->bottom()),
1.273 + p2i(from()->end()),
1.274 + pointer_delta(from()->end(),
1.275 + from()->bottom(),
1.276 + sizeof(char)));
1.277 + gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") "
1.278 + SIZE_FORMAT,
1.279 + p2i(to()->bottom()),
1.280 + p2i(to()->end()),
1.281 + pointer_delta( to()->end(),
1.282 + to()->bottom(),
1.283 + sizeof(char)));
1.284 + }
1.285 +
1.286 + // There's nothing to do if the new sizes are the same as the current
1.287 + if (requested_survivor_size == to()->capacity() &&
1.288 + requested_survivor_size == from()->capacity() &&
1.289 + requested_eden_size == eden()->capacity()) {
1.290 + if (PrintAdaptiveSizePolicy && Verbose) {
1.291 + gclog_or_tty->print_cr(" capacities are the right sizes, returning");
1.292 + }
1.293 + return;
1.294 + }
1.295 +
1.296 + char* eden_start = (char*)eden()->bottom();
1.297 + char* eden_end = (char*)eden()->end();
1.298 + char* from_start = (char*)from()->bottom();
1.299 + char* from_end = (char*)from()->end();
1.300 + char* to_start = (char*)to()->bottom();
1.301 + char* to_end = (char*)to()->end();
1.302 +
1.303 + const size_t alignment = os::vm_page_size();
1.304 + const bool maintain_minimum =
1.305 + (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
1.306 +
1.307 + // Check whether from space is below to space
1.308 + if (from_start < to_start) {
1.309 + // Eden, from, to
1.310 + if (PrintAdaptiveSizePolicy && Verbose) {
1.311 + gclog_or_tty->print_cr(" Eden, from, to:");
1.312 + }
1.313 +
1.314 + // Set eden
1.315 + // "requested_eden_size" is a goal for the size of eden
1.316 + // and may not be attainable. "eden_size" below is
1.317 + // calculated based on the location of from-space and
1.318 + // the goal for the size of eden. from-space is
1.319 + // fixed in place because it contains live data.
1.320 + // The calculation is done this way to avoid 32bit
1.321 + // overflow (i.e., eden_start + requested_eden_size
1.322 + // may too large for representation in 32bits).
1.323 + size_t eden_size;
1.324 + if (maintain_minimum) {
1.325 + // Only make eden larger than the requested size if
1.326 + // the minimum size of the generation has to be maintained.
1.327 + // This could be done in general but policy at a higher
1.328 + // level is determining a requested size for eden and that
1.329 + // should be honored unless there is a fundamental reason.
1.330 + eden_size = pointer_delta(from_start,
1.331 + eden_start,
1.332 + sizeof(char));
1.333 + } else {
1.334 + eden_size = MIN2(requested_eden_size,
1.335 + pointer_delta(from_start, eden_start, sizeof(char)));
1.336 + }
1.337 +
1.338 + eden_size = align_size_down(eden_size, alignment);
1.339 + eden_end = eden_start + eden_size;
1.340 + assert(eden_end >= eden_start, "addition overflowed");
1.341 +
1.342 + // To may resize into from space as long as it is clear of live data.
1.343 + // From space must remain page aligned, though, so we need to do some
1.344 + // extra calculations.
1.345 +
1.346 + // First calculate an optimal to-space
1.347 + to_end = (char*)virtual_space()->high();
1.348 + to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
1.349 + sizeof(char));
1.350 +
1.351 + // Does the optimal to-space overlap from-space?
1.352 + if (to_start < (char*)from()->end()) {
1.353 + // Calculate the minimum offset possible for from_end
1.354 + size_t from_size = pointer_delta(from()->top(), from_start, sizeof(char));
1.355 +
1.356 + // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
1.357 + if (from_size == 0) {
1.358 + from_size = alignment;
1.359 + } else {
1.360 + from_size = align_size_up(from_size, alignment);
1.361 + }
1.362 +
1.363 + from_end = from_start + from_size;
1.364 + assert(from_end > from_start, "addition overflow or from_size problem");
1.365 +
1.366 + guarantee(from_end <= (char*)from()->end(), "from_end moved to the right");
1.367 +
1.368 + // Now update to_start with the new from_end
1.369 + to_start = MAX2(from_end, to_start);
1.370 + } else {
1.371 + // If shrinking, move to-space down to abut the end of from-space
1.372 + // so that shrinking will move to-space down. If not shrinking
1.373 + // to-space is moving up to allow for growth on the next expansion.
1.374 + if (requested_eden_size <= cur_eden_size) {
1.375 + to_start = from_end;
1.376 + if (to_start + requested_survivor_size > to_start) {
1.377 + to_end = to_start + requested_survivor_size;
1.378 + }
1.379 + }
1.380 + // else leave to_end pointing to the high end of the virtual space.
1.381 + }
1.382 +
1.383 + guarantee(to_start != to_end, "to space is zero sized");
1.384 +
1.385 + if (PrintAdaptiveSizePolicy && Verbose) {
1.386 + gclog_or_tty->print_cr(" [eden_start .. eden_end): "
1.387 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.388 + p2i(eden_start),
1.389 + p2i(eden_end),
1.390 + pointer_delta(eden_end, eden_start, sizeof(char)));
1.391 + gclog_or_tty->print_cr(" [from_start .. from_end): "
1.392 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.393 + p2i(from_start),
1.394 + p2i(from_end),
1.395 + pointer_delta(from_end, from_start, sizeof(char)));
1.396 + gclog_or_tty->print_cr(" [ to_start .. to_end): "
1.397 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.398 + p2i(to_start),
1.399 + p2i(to_end),
1.400 + pointer_delta( to_end, to_start, sizeof(char)));
1.401 + }
1.402 + } else {
1.403 + // Eden, to, from
1.404 + if (PrintAdaptiveSizePolicy && Verbose) {
1.405 + gclog_or_tty->print_cr(" Eden, to, from:");
1.406 + }
1.407 +
1.408 + // Calculate the to-space boundaries based on
1.409 + // the start of from-space.
1.410 + to_end = from_start;
1.411 + to_start = (char*)pointer_delta(from_start,
1.412 + (char*)requested_survivor_size,
1.413 + sizeof(char));
1.414 + // Calculate the ideal eden boundaries.
1.415 + // eden_end is already at the bottom of the generation
1.416 + assert(eden_start == virtual_space()->low(),
1.417 + "Eden is not starting at the low end of the virtual space");
1.418 + if (eden_start + requested_eden_size >= eden_start) {
1.419 + eden_end = eden_start + requested_eden_size;
1.420 + } else {
1.421 + eden_end = to_start;
1.422 + }
1.423 +
1.424 + // Does eden intrude into to-space? to-space
1.425 + // gets priority but eden is not allowed to shrink
1.426 + // to 0.
1.427 + if (eden_end > to_start) {
1.428 + eden_end = to_start;
1.429 + }
1.430 +
1.431 + // Don't let eden shrink down to 0 or less.
1.432 + eden_end = MAX2(eden_end, eden_start + alignment);
1.433 + assert(eden_start + alignment >= eden_start, "Overflow");
1.434 +
1.435 + size_t eden_size;
1.436 + if (maintain_minimum) {
1.437 + // Use all the space available.
1.438 + eden_end = MAX2(eden_end, to_start);
1.439 + eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
1.440 + eden_size = MIN2(eden_size, cur_eden_size);
1.441 + } else {
1.442 + eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
1.443 + }
1.444 + eden_size = align_size_down(eden_size, alignment);
1.445 + assert(maintain_minimum || eden_size <= requested_eden_size,
1.446 + "Eden size is too large");
1.447 + assert(eden_size >= alignment, "Eden size is too small");
1.448 + eden_end = eden_start + eden_size;
1.449 +
1.450 + // Move to-space down to eden.
1.451 + if (requested_eden_size < cur_eden_size) {
1.452 + to_start = eden_end;
1.453 + if (to_start + requested_survivor_size > to_start) {
1.454 + to_end = MIN2(from_start, to_start + requested_survivor_size);
1.455 + } else {
1.456 + to_end = from_start;
1.457 + }
1.458 + }
1.459 +
1.460 + // eden_end may have moved so again make sure
1.461 + // the to-space and eden don't overlap.
1.462 + to_start = MAX2(eden_end, to_start);
1.463 +
1.464 + // from-space
1.465 + size_t from_used = from()->used();
1.466 + if (requested_survivor_size > from_used) {
1.467 + if (from_start + requested_survivor_size >= from_start) {
1.468 + from_end = from_start + requested_survivor_size;
1.469 + }
1.470 + if (from_end > virtual_space()->high()) {
1.471 + from_end = virtual_space()->high();
1.472 + }
1.473 + }
1.474 +
1.475 + assert(to_start >= eden_end, "to-space should be above eden");
1.476 + if (PrintAdaptiveSizePolicy && Verbose) {
1.477 + gclog_or_tty->print_cr(" [eden_start .. eden_end): "
1.478 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.479 + p2i(eden_start),
1.480 + p2i(eden_end),
1.481 + pointer_delta(eden_end, eden_start, sizeof(char)));
1.482 + gclog_or_tty->print_cr(" [ to_start .. to_end): "
1.483 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.484 + p2i(to_start),
1.485 + p2i(to_end),
1.486 + pointer_delta( to_end, to_start, sizeof(char)));
1.487 + gclog_or_tty->print_cr(" [from_start .. from_end): "
1.488 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.489 + p2i(from_start),
1.490 + p2i(from_end),
1.491 + pointer_delta(from_end, from_start, sizeof(char)));
1.492 + }
1.493 + }
1.494 +
1.495 +
1.496 + guarantee((HeapWord*)from_start <= from()->bottom(),
1.497 + "from start moved to the right");
1.498 + guarantee((HeapWord*)from_end >= from()->top(),
1.499 + "from end moved into live data");
1.500 + assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
1.501 + assert(is_object_aligned((intptr_t)from_start), "checking alignment");
1.502 + assert(is_object_aligned((intptr_t)to_start), "checking alignment");
1.503 +
1.504 + MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
1.505 + MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end);
1.506 + MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
1.507 +
1.508 + // Let's make sure the call to initialize doesn't reset "top"!
1.509 + HeapWord* old_from_top = from()->top();
1.510 +
1.511 + // For PrintAdaptiveSizePolicy block below
1.512 + size_t old_from = from()->capacity();
1.513 + size_t old_to = to()->capacity();
1.514 +
1.515 + // If not clearing the spaces, do some checking to verify that
1.516 + // the spaces are already mangled.
1.517 +
1.518 + // Must check mangling before the spaces are reshaped. Otherwise,
1.519 + // the bottom or end of one space may have moved into another
1.520 + // a failure of the check may not correctly indicate which space
1.521 + // is not properly mangled.
1.522 + if (ZapUnusedHeapArea) {
1.523 + HeapWord* limit = (HeapWord*) virtual_space()->high();
1.524 + eden()->check_mangled_unused_area(limit);
1.525 + from()->check_mangled_unused_area(limit);
1.526 + to()->check_mangled_unused_area(limit);
1.527 + }
1.528 +
1.529 + // The call to initialize NULL's the next compaction space
1.530 + eden()->initialize(edenMR,
1.531 + SpaceDecorator::Clear,
1.532 + SpaceDecorator::DontMangle);
1.533 + eden()->set_next_compaction_space(from());
1.534 + to()->initialize(toMR ,
1.535 + SpaceDecorator::Clear,
1.536 + SpaceDecorator::DontMangle);
1.537 + from()->initialize(fromMR,
1.538 + SpaceDecorator::DontClear,
1.539 + SpaceDecorator::DontMangle);
1.540 +
1.541 + assert(from()->top() == old_from_top, "from top changed!");
1.542 +
1.543 + if (PrintAdaptiveSizePolicy) {
1.544 + GenCollectedHeap* gch = GenCollectedHeap::heap();
1.545 + assert(gch->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
1.546 +
1.547 + gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
1.548 + "collection: %d "
1.549 + "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
1.550 + "(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
1.551 + gch->total_collections(),
1.552 + old_from, old_to,
1.553 + from()->capacity(),
1.554 + to()->capacity());
1.555 + gclog_or_tty->cr();
1.556 + }
1.557 +}
1.558 +
1.559 +void ASParNewGeneration::compute_new_size() {
1.560 + GenCollectedHeap* gch = GenCollectedHeap::heap();
1.561 + assert(gch->kind() == CollectedHeap::GenCollectedHeap,
1.562 + "not a CMS generational heap");
1.563 +
1.564 +
1.565 + CMSAdaptiveSizePolicy* size_policy =
1.566 + (CMSAdaptiveSizePolicy*)gch->gen_policy()->size_policy();
1.567 + assert(size_policy->is_gc_cms_adaptive_size_policy(),
1.568 + "Wrong type of size policy");
1.569 +
1.570 + size_t survived = from()->used();
1.571 + if (!survivor_overflow()) {
1.572 + // Keep running averages on how much survived
1.573 + size_policy->avg_survived()->sample(survived);
1.574 + } else {
1.575 + size_t promoted =
1.576 + (size_t) next_gen()->gc_stats()->avg_promoted()->last_sample();
1.577 + assert(promoted < gch->capacity(), "Conversion problem?");
1.578 + size_t survived_guess = survived + promoted;
1.579 + size_policy->avg_survived()->sample(survived_guess);
1.580 + }
1.581 +
1.582 + size_t survivor_limit = max_survivor_size();
1.583 + _tenuring_threshold =
1.584 + size_policy->compute_survivor_space_size_and_threshold(
1.585 + _survivor_overflow,
1.586 + _tenuring_threshold,
1.587 + survivor_limit);
1.588 + size_policy->avg_young_live()->sample(used());
1.589 + size_policy->avg_eden_live()->sample(eden()->used());
1.590 +
1.591 + size_policy->compute_eden_space_size(eden()->capacity(), max_gen_size());
1.592 +
1.593 + resize(size_policy->calculated_eden_size_in_bytes(),
1.594 + size_policy->calculated_survivor_size_in_bytes());
1.595 +
1.596 + if (UsePerfData) {
1.597 + CMSGCAdaptivePolicyCounters* counters =
1.598 + (CMSGCAdaptivePolicyCounters*) gch->collector_policy()->counters();
1.599 + assert(counters->kind() ==
1.600 + GCPolicyCounters::CMSGCAdaptivePolicyCountersKind,
1.601 + "Wrong kind of counters");
1.602 + counters->update_tenuring_threshold(_tenuring_threshold);
1.603 + counters->update_survivor_overflowed(_survivor_overflow);
1.604 + counters->update_young_capacity(capacity());
1.605 + }
1.606 +}
1.607 +
1.608 +
1.609 +#ifndef PRODUCT
1.610 +// Changes from PSYoungGen version
1.611 +// value of "alignment"
1.612 +void ASParNewGeneration::space_invariants() {
1.613 + const size_t alignment = os::vm_page_size();
1.614 +
1.615 + // Currently, our eden size cannot shrink to zero
1.616 + guarantee(eden()->capacity() >= alignment, "eden too small");
1.617 + guarantee(from()->capacity() >= alignment, "from too small");
1.618 + guarantee(to()->capacity() >= alignment, "to too small");
1.619 +
1.620 + // Relationship of spaces to each other
1.621 + char* eden_start = (char*)eden()->bottom();
1.622 + char* eden_end = (char*)eden()->end();
1.623 + char* from_start = (char*)from()->bottom();
1.624 + char* from_end = (char*)from()->end();
1.625 + char* to_start = (char*)to()->bottom();
1.626 + char* to_end = (char*)to()->end();
1.627 +
1.628 + guarantee(eden_start >= virtual_space()->low(), "eden bottom");
1.629 + guarantee(eden_start < eden_end, "eden space consistency");
1.630 + guarantee(from_start < from_end, "from space consistency");
1.631 + guarantee(to_start < to_end, "to space consistency");
1.632 +
1.633 + // Check whether from space is below to space
1.634 + if (from_start < to_start) {
1.635 + // Eden, from, to
1.636 + guarantee(eden_end <= from_start, "eden/from boundary");
1.637 + guarantee(from_end <= to_start, "from/to boundary");
1.638 + guarantee(to_end <= virtual_space()->high(), "to end");
1.639 + } else {
1.640 + // Eden, to, from
1.641 + guarantee(eden_end <= to_start, "eden/to boundary");
1.642 + guarantee(to_end <= from_start, "to/from boundary");
1.643 + guarantee(from_end <= virtual_space()->high(), "from end");
1.644 + }
1.645 +
1.646 + // More checks that the virtual space is consistent with the spaces
1.647 + assert(virtual_space()->committed_size() >=
1.648 + (eden()->capacity() +
1.649 + to()->capacity() +
1.650 + from()->capacity()), "Committed size is inconsistent");
1.651 + assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
1.652 + "Space invariant");
1.653 + char* eden_top = (char*)eden()->top();
1.654 + char* from_top = (char*)from()->top();
1.655 + char* to_top = (char*)to()->top();
1.656 + assert(eden_top <= virtual_space()->high(), "eden top");
1.657 + assert(from_top <= virtual_space()->high(), "from top");
1.658 + assert(to_top <= virtual_space()->high(), "to top");
1.659 +}
1.660 +#endif
