1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.cpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,469 @@
1.4 +/*
1.5 + * Copyright 2003-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +# include "incls/_precompiled.incl"
1.29 +# include "incls/_asPSYoungGen.cpp.incl"
1.30 +
1.31 +ASPSYoungGen::ASPSYoungGen(size_t init_byte_size,
1.32 + size_t minimum_byte_size,
1.33 + size_t byte_size_limit) :
1.34 + PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit),
1.35 + _gen_size_limit(byte_size_limit) {
1.36 +}
1.37 +
1.38 +
1.39 +ASPSYoungGen::ASPSYoungGen(PSVirtualSpace* vs,
1.40 + size_t init_byte_size,
1.41 + size_t minimum_byte_size,
1.42 + size_t byte_size_limit) :
1.43 + //PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit),
1.44 + PSYoungGen(vs->committed_size(), minimum_byte_size, byte_size_limit),
1.45 + _gen_size_limit(byte_size_limit) {
1.46 +
1.47 + assert(vs->committed_size() == init_byte_size, "Cannot replace with");
1.48 +
1.49 + _virtual_space = vs;
1.50 +}
1.51 +
1.52 +void ASPSYoungGen::initialize_virtual_space(ReservedSpace rs,
1.53 + size_t alignment) {
1.54 + assert(_init_gen_size != 0, "Should have a finite size");
1.55 + _virtual_space = new PSVirtualSpaceHighToLow(rs, alignment);
1.56 + if (!_virtual_space->expand_by(_init_gen_size)) {
1.57 + vm_exit_during_initialization("Could not reserve enough space for "
1.58 + "object heap");
1.59 + }
1.60 +}
1.61 +
1.62 +void ASPSYoungGen::initialize(ReservedSpace rs, size_t alignment) {
1.63 + initialize_virtual_space(rs, alignment);
1.64 + initialize_work();
1.65 +}
1.66 +
1.67 +size_t ASPSYoungGen::available_for_expansion() {
1.68 +
1.69 + size_t current_committed_size = virtual_space()->committed_size();
1.70 + assert((gen_size_limit() >= current_committed_size),
1.71 + "generation size limit is wrong");
1.72 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.73 + size_t result = gen_size_limit() - current_committed_size;
1.74 + size_t result_aligned = align_size_down(result, heap->young_gen_alignment());
1.75 + return result_aligned;
1.76 +}
1.77 +
1.78 +// Return the number of bytes the young gen is willing give up.
1.79 +//
1.80 +// Future implementations could check the survivors and if to_space is in the
1.81 +// right place (below from_space), take a chunk from to_space.
1.82 +size_t ASPSYoungGen::available_for_contraction() {
1.83 +
1.84 + size_t uncommitted_bytes = virtual_space()->uncommitted_size();
1.85 + if (uncommitted_bytes != 0) {
1.86 + return uncommitted_bytes;
1.87 + }
1.88 +
1.89 + if (eden_space()->is_empty()) {
1.90 + // Respect the minimum size for eden and for the young gen as a whole.
1.91 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.92 + const size_t eden_alignment = heap->intra_generation_alignment();
1.93 + const size_t gen_alignment = heap->young_gen_alignment();
1.94 +
1.95 + assert(eden_space()->capacity_in_bytes() >= eden_alignment,
1.96 + "Alignment is wrong");
1.97 + size_t eden_avail = eden_space()->capacity_in_bytes() - eden_alignment;
1.98 + eden_avail = align_size_down(eden_avail, gen_alignment);
1.99 +
1.100 + assert(virtual_space()->committed_size() >= min_gen_size(),
1.101 + "minimum gen size is wrong");
1.102 + size_t gen_avail = virtual_space()->committed_size() - min_gen_size();
1.103 + assert(virtual_space()->is_aligned(gen_avail), "not aligned");
1.104 +
1.105 + const size_t max_contraction = MIN2(eden_avail, gen_avail);
1.106 + // See comment for ASPSOldGen::available_for_contraction()
1.107 + // for reasons the "increment" fraction is used.
1.108 + PSAdaptiveSizePolicy* policy = heap->size_policy();
1.109 + size_t result = policy->eden_increment_aligned_down(max_contraction);
1.110 + size_t result_aligned = align_size_down(result, gen_alignment);
1.111 + if (PrintAdaptiveSizePolicy && Verbose) {
1.112 + gclog_or_tty->print_cr("ASPSYoungGen::available_for_contraction: %d K",
1.113 + result_aligned/K);
1.114 + gclog_or_tty->print_cr(" max_contraction %d K", max_contraction/K);
1.115 + gclog_or_tty->print_cr(" eden_avail %d K", eden_avail/K);
1.116 + gclog_or_tty->print_cr(" gen_avail %d K", gen_avail/K);
1.117 + }
1.118 + return result_aligned;
1.119 +
1.120 + }
1.121 +
1.122 + return 0;
1.123 +}
1.124 +
1.125 +// The current implementation only considers to the end of eden.
1.126 +// If to_space is below from_space, to_space is not considered.
1.127 +// to_space can be.
1.128 +size_t ASPSYoungGen::available_to_live() {
1.129 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.130 + const size_t alignment = heap->intra_generation_alignment();
1.131 +
1.132 + // Include any space that is committed but is not in eden.
1.133 + size_t available = pointer_delta(eden_space()->bottom(),
1.134 + virtual_space()->low(),
1.135 + sizeof(char));
1.136 +
1.137 + const size_t eden_capacity = eden_space()->capacity_in_bytes();
1.138 + if (eden_space()->is_empty() && eden_capacity > alignment) {
1.139 + available += eden_capacity - alignment;
1.140 + }
1.141 + return available;
1.142 +}
1.143 +
1.144 +// Similar to PSYoungGen::resize_generation() but
1.145 +// allows sum of eden_size and 2 * survivor_size to exceed _max_gen_size
1.146 +// expands at the low end of the virtual space
1.147 +// moves the boundary between the generations in order to expand
1.148 +// some additional diagnostics
1.149 +// If no additional changes are required, this can be deleted
1.150 +// and the changes factored back into PSYoungGen::resize_generation().
1.151 +bool ASPSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
1.152 + const size_t alignment = virtual_space()->alignment();
1.153 + size_t orig_size = virtual_space()->committed_size();
1.154 + bool size_changed = false;
1.155 +
1.156 + // There used to be a guarantee here that
1.157 + // (eden_size + 2*survivor_size) <= _max_gen_size
1.158 + // This requirement is enforced by the calculation of desired_size
1.159 + // below. It may not be true on entry since the size of the
1.160 + // eden_size is no bounded by the generation size.
1.161 +
1.162 + assert(max_size() == reserved().byte_size(), "max gen size problem?");
1.163 + assert(min_gen_size() <= orig_size && orig_size <= max_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, gen_size_limit()),
1.170 + min_gen_size());
1.171 + assert(desired_size <= gen_size_limit(), "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 + if (!virtual_space()->expand_by(change)) {
1.177 + return false;
1.178 + }
1.179 + size_changed = true;
1.180 + } else if (desired_size < orig_size) {
1.181 + size_t desired_change = orig_size - desired_size;
1.182 +
1.183 + // How much is available for shrinking.
1.184 + size_t available_bytes = limit_gen_shrink(desired_change);
1.185 + size_t change = MIN2(desired_change, available_bytes);
1.186 + virtual_space()->shrink_by(change);
1.187 + size_changed = true;
1.188 + } else {
1.189 + if (Verbose && PrintGC) {
1.190 + if (orig_size == gen_size_limit()) {
1.191 + gclog_or_tty->print_cr("ASPSYoung generation size at maximum: "
1.192 + SIZE_FORMAT "K", orig_size/K);
1.193 + } else if (orig_size == min_gen_size()) {
1.194 + gclog_or_tty->print_cr("ASPSYoung generation size at minium: "
1.195 + SIZE_FORMAT "K", orig_size/K);
1.196 + }
1.197 + }
1.198 + }
1.199 +
1.200 + if (size_changed) {
1.201 + reset_after_change();
1.202 + if (Verbose && PrintGC) {
1.203 + size_t current_size = virtual_space()->committed_size();
1.204 + gclog_or_tty->print_cr("ASPSYoung generation size changed: "
1.205 + SIZE_FORMAT "K->" SIZE_FORMAT "K",
1.206 + orig_size/K, current_size/K);
1.207 + }
1.208 + }
1.209 +
1.210 + guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
1.211 + virtual_space()->committed_size() == max_size(), "Sanity");
1.212 +
1.213 + return true;
1.214 +}
1.215 +
1.216 +// Similar to PSYoungGen::resize_spaces() but
1.217 +// eden always starts at the low end of the committed virtual space
1.218 +// current implementation does not allow holes between the spaces
1.219 +// _young_generation_boundary has to be reset because it changes.
1.220 +// so additional verification
1.221 +void ASPSYoungGen::resize_spaces(size_t requested_eden_size,
1.222 + size_t requested_survivor_size) {
1.223 + assert(requested_eden_size > 0 && requested_survivor_size > 0,
1.224 + "just checking");
1.225 +
1.226 + space_invariants();
1.227 +
1.228 + // We require eden and to space to be empty
1.229 + if ((!eden_space()->is_empty()) || (!to_space()->is_empty())) {
1.230 + return;
1.231 + }
1.232 +
1.233 + if (PrintAdaptiveSizePolicy && Verbose) {
1.234 + gclog_or_tty->print_cr("PSYoungGen::resize_spaces(requested_eden_size: "
1.235 + SIZE_FORMAT
1.236 + ", requested_survivor_size: " SIZE_FORMAT ")",
1.237 + requested_eden_size, requested_survivor_size);
1.238 + gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") "
1.239 + SIZE_FORMAT,
1.240 + eden_space()->bottom(),
1.241 + eden_space()->end(),
1.242 + pointer_delta(eden_space()->end(),
1.243 + eden_space()->bottom(),
1.244 + sizeof(char)));
1.245 + gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") "
1.246 + SIZE_FORMAT,
1.247 + from_space()->bottom(),
1.248 + from_space()->end(),
1.249 + pointer_delta(from_space()->end(),
1.250 + from_space()->bottom(),
1.251 + sizeof(char)));
1.252 + gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") "
1.253 + SIZE_FORMAT,
1.254 + to_space()->bottom(),
1.255 + to_space()->end(),
1.256 + pointer_delta( to_space()->end(),
1.257 + to_space()->bottom(),
1.258 + sizeof(char)));
1.259 + }
1.260 +
1.261 + // There's nothing to do if the new sizes are the same as the current
1.262 + if (requested_survivor_size == to_space()->capacity_in_bytes() &&
1.263 + requested_survivor_size == from_space()->capacity_in_bytes() &&
1.264 + requested_eden_size == eden_space()->capacity_in_bytes()) {
1.265 + if (PrintAdaptiveSizePolicy && Verbose) {
1.266 + gclog_or_tty->print_cr(" capacities are the right sizes, returning");
1.267 + }
1.268 + return;
1.269 + }
1.270 +
1.271 + char* eden_start = (char*)virtual_space()->low();
1.272 + char* eden_end = (char*)eden_space()->end();
1.273 + char* from_start = (char*)from_space()->bottom();
1.274 + char* from_end = (char*)from_space()->end();
1.275 + char* to_start = (char*)to_space()->bottom();
1.276 + char* to_end = (char*)to_space()->end();
1.277 +
1.278 + assert(eden_start < from_start, "Cannot push into from_space");
1.279 +
1.280 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.281 + const size_t alignment = heap->intra_generation_alignment();
1.282 +
1.283 + // Check whether from space is below to space
1.284 + if (from_start < to_start) {
1.285 + // Eden, from, to
1.286 + if (PrintAdaptiveSizePolicy && Verbose) {
1.287 + gclog_or_tty->print_cr(" Eden, from, to:");
1.288 + }
1.289 +
1.290 + // Set eden
1.291 + // Compute how big eden can be, then adjust end.
1.292 + // See comment in PSYoungGen::resize_spaces() on
1.293 + // calculating eden_end.
1.294 + const size_t eden_size = MIN2(requested_eden_size,
1.295 + pointer_delta(from_start,
1.296 + eden_start,
1.297 + sizeof(char)));
1.298 + eden_end = eden_start + eden_size;
1.299 + assert(eden_end >= eden_start, "addition overflowed")
1.300 +
1.301 + // To may resize into from space as long as it is clear of live data.
1.302 + // From space must remain page aligned, though, so we need to do some
1.303 + // extra calculations.
1.304 +
1.305 + // First calculate an optimal to-space
1.306 + to_end = (char*)virtual_space()->high();
1.307 + to_start = (char*)pointer_delta(to_end,
1.308 + (char*)requested_survivor_size,
1.309 + sizeof(char));
1.310 +
1.311 + // Does the optimal to-space overlap from-space?
1.312 + if (to_start < (char*)from_space()->end()) {
1.313 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.314 +
1.315 + // Calculate the minimum offset possible for from_end
1.316 + size_t from_size =
1.317 + pointer_delta(from_space()->top(), from_start, sizeof(char));
1.318 +
1.319 + // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
1.320 + if (from_size == 0) {
1.321 + from_size = alignment;
1.322 + } else {
1.323 + from_size = align_size_up(from_size, alignment);
1.324 + }
1.325 +
1.326 + from_end = from_start + from_size;
1.327 + assert(from_end > from_start, "addition overflow or from_size problem");
1.328 +
1.329 + guarantee(from_end <= (char*)from_space()->end(),
1.330 + "from_end moved to the right");
1.331 +
1.332 + // Now update to_start with the new from_end
1.333 + to_start = MAX2(from_end, to_start);
1.334 + }
1.335 +
1.336 + guarantee(to_start != to_end, "to space is zero sized");
1.337 +
1.338 + if (PrintAdaptiveSizePolicy && Verbose) {
1.339 + gclog_or_tty->print_cr(" [eden_start .. eden_end): "
1.340 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.341 + eden_start,
1.342 + eden_end,
1.343 + pointer_delta(eden_end, eden_start, sizeof(char)));
1.344 + gclog_or_tty->print_cr(" [from_start .. from_end): "
1.345 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.346 + from_start,
1.347 + from_end,
1.348 + pointer_delta(from_end, from_start, sizeof(char)));
1.349 + gclog_or_tty->print_cr(" [ to_start .. to_end): "
1.350 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.351 + to_start,
1.352 + to_end,
1.353 + pointer_delta( to_end, to_start, sizeof(char)));
1.354 + }
1.355 + } else {
1.356 + // Eden, to, from
1.357 + if (PrintAdaptiveSizePolicy && Verbose) {
1.358 + gclog_or_tty->print_cr(" Eden, to, from:");
1.359 + }
1.360 +
1.361 + // To space gets priority over eden resizing. Note that we position
1.362 + // to space as if we were able to resize from space, even though from
1.363 + // space is not modified.
1.364 + // Giving eden priority was tried and gave poorer performance.
1.365 + to_end = (char*)pointer_delta(virtual_space()->high(),
1.366 + (char*)requested_survivor_size,
1.367 + sizeof(char));
1.368 + to_end = MIN2(to_end, from_start);
1.369 + to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
1.370 + sizeof(char));
1.371 + // if the space sizes are to be increased by several times then
1.372 + // 'to_start' will point beyond the young generation. In this case
1.373 + // 'to_start' should be adjusted.
1.374 + to_start = MAX2(to_start, eden_start + alignment);
1.375 +
1.376 + // Compute how big eden can be, then adjust end.
1.377 + // See comment in PSYoungGen::resize_spaces() on
1.378 + // calculating eden_end.
1.379 + const size_t eden_size = MIN2(requested_eden_size,
1.380 + pointer_delta(to_start,
1.381 + eden_start,
1.382 + sizeof(char)));
1.383 + eden_end = eden_start + eden_size;
1.384 + assert(eden_end >= eden_start, "addition overflowed")
1.385 +
1.386 + // Don't let eden shrink down to 0 or less.
1.387 + eden_end = MAX2(eden_end, eden_start + alignment);
1.388 + to_start = MAX2(to_start, eden_end);
1.389 +
1.390 + if (PrintAdaptiveSizePolicy && Verbose) {
1.391 + gclog_or_tty->print_cr(" [eden_start .. eden_end): "
1.392 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.393 + eden_start,
1.394 + eden_end,
1.395 + pointer_delta(eden_end, eden_start, sizeof(char)));
1.396 + gclog_or_tty->print_cr(" [ to_start .. to_end): "
1.397 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.398 + to_start,
1.399 + to_end,
1.400 + pointer_delta( to_end, to_start, sizeof(char)));
1.401 + gclog_or_tty->print_cr(" [from_start .. from_end): "
1.402 + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
1.403 + from_start,
1.404 + from_end,
1.405 + pointer_delta(from_end, from_start, sizeof(char)));
1.406 + }
1.407 + }
1.408 +
1.409 +
1.410 + guarantee((HeapWord*)from_start <= from_space()->bottom(),
1.411 + "from start moved to the right");
1.412 + guarantee((HeapWord*)from_end >= from_space()->top(),
1.413 + "from end moved into live data");
1.414 + assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
1.415 + assert(is_object_aligned((intptr_t)from_start), "checking alignment");
1.416 + assert(is_object_aligned((intptr_t)to_start), "checking alignment");
1.417 +
1.418 + MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
1.419 + MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end);
1.420 + MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
1.421 +
1.422 + // Let's make sure the call to initialize doesn't reset "top"!
1.423 + DEBUG_ONLY(HeapWord* old_from_top = from_space()->top();)
1.424 +
1.425 + // For PrintAdaptiveSizePolicy block below
1.426 + size_t old_from = from_space()->capacity_in_bytes();
1.427 + size_t old_to = to_space()->capacity_in_bytes();
1.428 +
1.429 + eden_space()->initialize(edenMR, true);
1.430 + to_space()->initialize(toMR , true);
1.431 + from_space()->initialize(fromMR, false); // Note, not cleared!
1.432 + PSScavenge::set_young_generation_boundary(eden_space()->bottom());
1.433 +
1.434 + assert(from_space()->top() == old_from_top, "from top changed!");
1.435 +
1.436 + if (PrintAdaptiveSizePolicy) {
1.437 + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
1.438 + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
1.439 +
1.440 + gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
1.441 + "collection: %d "
1.442 + "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
1.443 + "(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
1.444 + heap->total_collections(),
1.445 + old_from, old_to,
1.446 + from_space()->capacity_in_bytes(),
1.447 + to_space()->capacity_in_bytes());
1.448 + gclog_or_tty->cr();
1.449 + }
1.450 + space_invariants();
1.451 +}
1.452 +
1.453 +void ASPSYoungGen::reset_after_change() {
1.454 + assert_locked_or_safepoint(Heap_lock);
1.455 +
1.456 + _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
1.457 + (HeapWord*)virtual_space()->high_boundary());
1.458 + PSScavenge::reference_processor()->set_span(_reserved);
1.459 +
1.460 + HeapWord* new_eden_bottom = (HeapWord*)virtual_space()->low();
1.461 + HeapWord* eden_bottom = eden_space()->bottom();
1.462 + if (new_eden_bottom != eden_bottom) {
1.463 + MemRegion eden_mr(new_eden_bottom, eden_space()->end());
1.464 + eden_space()->initialize(eden_mr, true);
1.465 + PSScavenge::set_young_generation_boundary(eden_space()->bottom());
1.466 + }
1.467 + MemRegion cmr((HeapWord*)virtual_space()->low(),
1.468 + (HeapWord*)virtual_space()->high());
1.469 + Universe::heap()->barrier_set()->resize_covered_region(cmr);
1.470 +
1.471 + space_invariants();
1.472 +}
