diff -r 000000000000 -r a61af66fc99e src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,811 @@ +/* + * Copyright 2001-2007 Sun Microsystems, Inc. All Rights Reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +# include "incls/_precompiled.incl" +# include "incls/_psYoungGen.cpp.incl" + +PSYoungGen::PSYoungGen(size_t initial_size, + size_t min_size, + size_t max_size) : + _init_gen_size(initial_size), + _min_gen_size(min_size), + _max_gen_size(max_size) +{} + +void PSYoungGen::initialize_virtual_space(ReservedSpace rs, size_t alignment) { + assert(_init_gen_size != 0, "Should have a finite size"); + _virtual_space = new PSVirtualSpace(rs, alignment); + if (!_virtual_space->expand_by(_init_gen_size)) { + vm_exit_during_initialization("Could not reserve enough space for " + "object heap"); + } +} + +void PSYoungGen::initialize(ReservedSpace rs, size_t alignment) { + initialize_virtual_space(rs, alignment); + initialize_work(); +} + +void PSYoungGen::initialize_work() { + + _reserved = MemRegion((HeapWord*)_virtual_space->low_boundary(), + (HeapWord*)_virtual_space->high_boundary()); + + MemRegion cmr((HeapWord*)_virtual_space->low(), + (HeapWord*)_virtual_space->high()); + Universe::heap()->barrier_set()->resize_covered_region(cmr); + + if (UseNUMA) { + _eden_space = new MutableNUMASpace(); + } else { + _eden_space = new MutableSpace(); + } + _from_space = new MutableSpace(); + _to_space = new MutableSpace(); + + if (_eden_space == NULL || _from_space == NULL || _to_space == NULL) { + vm_exit_during_initialization("Could not allocate a young gen space"); + } + + // Allocate the mark sweep views of spaces + _eden_mark_sweep = + new PSMarkSweepDecorator(_eden_space, NULL, MarkSweepDeadRatio); + _from_mark_sweep = + new PSMarkSweepDecorator(_from_space, NULL, MarkSweepDeadRatio); + _to_mark_sweep = + new PSMarkSweepDecorator(_to_space, NULL, MarkSweepDeadRatio); + + if (_eden_mark_sweep == NULL || + _from_mark_sweep == NULL || + _to_mark_sweep == NULL) { + vm_exit_during_initialization("Could not complete allocation" + " of the young generation"); + } + + // Generation Counters - generation 0, 3 subspaces + _gen_counters = new PSGenerationCounters("new", 0, 3, _virtual_space); + + // Compute maximum space sizes for performance counters + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + size_t alignment = heap->intra_generation_alignment(); + size_t size = _virtual_space->reserved_size(); + + size_t max_survivor_size; + size_t max_eden_size; + + if (UseAdaptiveSizePolicy) { + max_survivor_size = size / MinSurvivorRatio; + + // round the survivor space size down to the nearest alignment + // and make sure its size is greater than 0. + max_survivor_size = align_size_down(max_survivor_size, alignment); + max_survivor_size = MAX2(max_survivor_size, alignment); + + // set the maximum size of eden to be the size of the young gen + // less two times the minimum survivor size. The minimum survivor + // size for UseAdaptiveSizePolicy is one alignment. + max_eden_size = size - 2 * alignment; + } else { + max_survivor_size = size / InitialSurvivorRatio; + + // round the survivor space size down to the nearest alignment + // and make sure its size is greater than 0. + max_survivor_size = align_size_down(max_survivor_size, alignment); + max_survivor_size = MAX2(max_survivor_size, alignment); + + // set the maximum size of eden to be the size of the young gen + // less two times the survivor size when the generation is 100% + // committed. The minimum survivor size for -UseAdaptiveSizePolicy + // is dependent on the committed portion (current capacity) of the + // generation - the less space committed, the smaller the survivor + // space, possibly as small as an alignment. However, we are interested + // in the case where the young generation is 100% committed, as this + // is the point where eden reachs its maximum size. At this point, + // the size of a survivor space is max_survivor_size. + max_eden_size = size - 2 * max_survivor_size; + } + + _eden_counters = new SpaceCounters("eden", 0, max_eden_size, _eden_space, + _gen_counters); + _from_counters = new SpaceCounters("s0", 1, max_survivor_size, _from_space, + _gen_counters); + _to_counters = new SpaceCounters("s1", 2, max_survivor_size, _to_space, + _gen_counters); + + compute_initial_space_boundaries(); +} + +void PSYoungGen::compute_initial_space_boundaries() { + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + + // Compute sizes + size_t alignment = heap->intra_generation_alignment(); + size_t size = _virtual_space->committed_size(); + + size_t survivor_size = size / InitialSurvivorRatio; + survivor_size = align_size_down(survivor_size, alignment); + // ... but never less than an alignment + survivor_size = MAX2(survivor_size, alignment); + + // Young generation is eden + 2 survivor spaces + size_t eden_size = size - (2 * survivor_size); + + // Now go ahead and set 'em. + set_space_boundaries(eden_size, survivor_size); + space_invariants(); + + if (UsePerfData) { + _eden_counters->update_capacity(); + _from_counters->update_capacity(); + _to_counters->update_capacity(); + } +} + +void PSYoungGen::set_space_boundaries(size_t eden_size, size_t survivor_size) { + assert(eden_size < _virtual_space->committed_size(), "just checking"); + assert(eden_size > 0 && survivor_size > 0, "just checking"); + + // Initial layout is Eden, to, from. After swapping survivor spaces, + // that leaves us with Eden, from, to, which is step one in our two + // step resize-with-live-data procedure. + char *eden_start = _virtual_space->low(); + char *to_start = eden_start + eden_size; + char *from_start = to_start + survivor_size; + char *from_end = from_start + survivor_size; + + assert(from_end == _virtual_space->high(), "just checking"); + assert(is_object_aligned((intptr_t)eden_start), "checking alignment"); + assert(is_object_aligned((intptr_t)to_start), "checking alignment"); + assert(is_object_aligned((intptr_t)from_start), "checking alignment"); + + MemRegion eden_mr((HeapWord*)eden_start, (HeapWord*)to_start); + MemRegion to_mr ((HeapWord*)to_start, (HeapWord*)from_start); + MemRegion from_mr((HeapWord*)from_start, (HeapWord*)from_end); + + eden_space()->initialize(eden_mr, true); + to_space()->initialize(to_mr , true); + from_space()->initialize(from_mr, true); +} + +#ifndef PRODUCT +void PSYoungGen::space_invariants() { + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + const size_t alignment = heap->intra_generation_alignment(); + + // Currently, our eden size cannot shrink to zero + guarantee(eden_space()->capacity_in_bytes() >= alignment, "eden too small"); + guarantee(from_space()->capacity_in_bytes() >= alignment, "from too small"); + guarantee(to_space()->capacity_in_bytes() >= alignment, "to too small"); + + // Relationship of spaces to each other + char* eden_start = (char*)eden_space()->bottom(); + char* eden_end = (char*)eden_space()->end(); + char* from_start = (char*)from_space()->bottom(); + char* from_end = (char*)from_space()->end(); + char* to_start = (char*)to_space()->bottom(); + char* to_end = (char*)to_space()->end(); + + guarantee(eden_start >= _virtual_space->low(), "eden bottom"); + guarantee(eden_start < eden_end, "eden space consistency"); + guarantee(from_start < from_end, "from space consistency"); + guarantee(to_start < to_end, "to space consistency"); + + // Check whether from space is below to space + if (from_start < to_start) { + // Eden, from, to + guarantee(eden_end <= from_start, "eden/from boundary"); + guarantee(from_end <= to_start, "from/to boundary"); + guarantee(to_end <= _virtual_space->high(), "to end"); + } else { + // Eden, to, from + guarantee(eden_end <= to_start, "eden/to boundary"); + guarantee(to_end <= from_start, "to/from boundary"); + guarantee(from_end <= _virtual_space->high(), "from end"); + } + + // More checks that the virtual space is consistent with the spaces + assert(_virtual_space->committed_size() >= + (eden_space()->capacity_in_bytes() + + to_space()->capacity_in_bytes() + + from_space()->capacity_in_bytes()), "Committed size is inconsistent"); + assert(_virtual_space->committed_size() <= _virtual_space->reserved_size(), + "Space invariant"); + char* eden_top = (char*)eden_space()->top(); + char* from_top = (char*)from_space()->top(); + char* to_top = (char*)to_space()->top(); + assert(eden_top <= _virtual_space->high(), "eden top"); + assert(from_top <= _virtual_space->high(), "from top"); + assert(to_top <= _virtual_space->high(), "to top"); + + _virtual_space->verify(); +} +#endif + +void PSYoungGen::resize(size_t eden_size, size_t survivor_size) { + // Resize the generation if needed. If the generation resize + // reports false, do not attempt to resize the spaces. + if (resize_generation(eden_size, survivor_size)) { + // Then we lay out the spaces inside the generation + resize_spaces(eden_size, survivor_size); + + space_invariants(); + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("Young generation size: " + "desired eden: " SIZE_FORMAT " survivor: " SIZE_FORMAT + " used: " SIZE_FORMAT " capacity: " SIZE_FORMAT + " gen limits: " SIZE_FORMAT " / " SIZE_FORMAT, + eden_size, survivor_size, used_in_bytes(), capacity_in_bytes(), + _max_gen_size, min_gen_size()); + } + } +} + + +bool PSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) { + const size_t alignment = _virtual_space->alignment(); + size_t orig_size = _virtual_space->committed_size(); + bool size_changed = false; + + // There used to be this guarantee there. + // guarantee ((eden_size + 2*survivor_size) <= _max_gen_size, "incorrect input arguments"); + // Code below forces this requirement. In addition the desired eden + // size and disired survivor sizes are desired goals and may + // exceed the total generation size. + + assert(min_gen_size() <= orig_size && orig_size <= max_size(), "just checking"); + + // Adjust new generation size + const size_t eden_plus_survivors = + align_size_up(eden_size + 2 * survivor_size, alignment); + size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_size()), + min_gen_size()); + assert(desired_size <= max_size(), "just checking"); + + if (desired_size > orig_size) { + // Grow the generation + size_t change = desired_size - orig_size; + assert(change % alignment == 0, "just checking"); + if (!_virtual_space->expand_by(change)) { + return false; // Error if we fail to resize! + } + + size_changed = true; + } else if (desired_size < orig_size) { + size_t desired_change = orig_size - desired_size; + assert(desired_change % alignment == 0, "just checking"); + + desired_change = limit_gen_shrink(desired_change); + + if (desired_change > 0) { + virtual_space()->shrink_by(desired_change); + reset_survivors_after_shrink(); + + size_changed = true; + } + } else { + if (Verbose && PrintGC) { + if (orig_size == gen_size_limit()) { + gclog_or_tty->print_cr("PSYoung generation size at maximum: " + SIZE_FORMAT "K", orig_size/K); + } else if (orig_size == min_gen_size()) { + gclog_or_tty->print_cr("PSYoung generation size at minium: " + SIZE_FORMAT "K", orig_size/K); + } + } + } + + if (size_changed) { + post_resize(); + + if (Verbose && PrintGC) { + size_t current_size = _virtual_space->committed_size(); + gclog_or_tty->print_cr("PSYoung generation size changed: " + SIZE_FORMAT "K->" SIZE_FORMAT "K", + orig_size/K, current_size/K); + } + } + + guarantee(eden_plus_survivors <= _virtual_space->committed_size() || + _virtual_space->committed_size() == max_size(), "Sanity"); + + return true; +} + + +void PSYoungGen::resize_spaces(size_t requested_eden_size, + size_t requested_survivor_size) { + assert(UseAdaptiveSizePolicy, "sanity check"); + assert(requested_eden_size > 0 && requested_survivor_size > 0, + "just checking"); + + // We require eden and to space to be empty + if ((!eden_space()->is_empty()) || (!to_space()->is_empty())) { + return; + } + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr("PSYoungGen::resize_spaces(requested_eden_size: " + SIZE_FORMAT + ", requested_survivor_size: " SIZE_FORMAT ")", + requested_eden_size, requested_survivor_size); + gclog_or_tty->print_cr(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") " + SIZE_FORMAT, + eden_space()->bottom(), + eden_space()->end(), + pointer_delta(eden_space()->end(), + eden_space()->bottom(), + sizeof(char))); + gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") " + SIZE_FORMAT, + from_space()->bottom(), + from_space()->end(), + pointer_delta(from_space()->end(), + from_space()->bottom(), + sizeof(char))); + gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") " + SIZE_FORMAT, + to_space()->bottom(), + to_space()->end(), + pointer_delta( to_space()->end(), + to_space()->bottom(), + sizeof(char))); + } + + // There's nothing to do if the new sizes are the same as the current + if (requested_survivor_size == to_space()->capacity_in_bytes() && + requested_survivor_size == from_space()->capacity_in_bytes() && + requested_eden_size == eden_space()->capacity_in_bytes()) { + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr(" capacities are the right sizes, returning"); + } + return; + } + + char* eden_start = (char*)eden_space()->bottom(); + char* eden_end = (char*)eden_space()->end(); + char* from_start = (char*)from_space()->bottom(); + char* from_end = (char*)from_space()->end(); + char* to_start = (char*)to_space()->bottom(); + char* to_end = (char*)to_space()->end(); + + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + const size_t alignment = heap->intra_generation_alignment(); + const bool maintain_minimum = + (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size(); + + // Check whether from space is below to space + if (from_start < to_start) { + // Eden, from, to + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr(" Eden, from, to:"); + } + + // Set eden + // "requested_eden_size" is a goal for the size of eden + // and may not be attainable. "eden_size" below is + // calculated based on the location of from-space and + // the goal for the size of eden. from-space is + // fixed in place because it contains live data. + // The calculation is done this way to avoid 32bit + // overflow (i.e., eden_start + requested_eden_size + // may too large for representation in 32bits). + size_t eden_size; + if (maintain_minimum) { + // Only make eden larger than the requested size if + // the minimum size of the generation has to be maintained. + // This could be done in general but policy at a higher + // level is determining a requested size for eden and that + // should be honored unless there is a fundamental reason. + eden_size = pointer_delta(from_start, + eden_start, + sizeof(char)); + } else { + eden_size = MIN2(requested_eden_size, + pointer_delta(from_start, eden_start, sizeof(char))); + } + + eden_end = eden_start + eden_size; + assert(eden_end >= eden_start, "addition overflowed") + + // To may resize into from space as long as it is clear of live data. + // From space must remain page aligned, though, so we need to do some + // extra calculations. + + // First calculate an optimal to-space + to_end = (char*)_virtual_space->high(); + to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size, + sizeof(char)); + + // Does the optimal to-space overlap from-space? + if (to_start < (char*)from_space()->end()) { + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + + // Calculate the minimum offset possible for from_end + size_t from_size = pointer_delta(from_space()->top(), from_start, sizeof(char)); + + // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME! + if (from_size == 0) { + from_size = alignment; + } else { + from_size = align_size_up(from_size, alignment); + } + + from_end = from_start + from_size; + assert(from_end > from_start, "addition overflow or from_size problem"); + + guarantee(from_end <= (char*)from_space()->end(), "from_end moved to the right"); + + // Now update to_start with the new from_end + to_start = MAX2(from_end, to_start); + } + + guarantee(to_start != to_end, "to space is zero sized"); + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr(" [eden_start .. eden_end): " + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, + eden_start, + eden_end, + pointer_delta(eden_end, eden_start, sizeof(char))); + gclog_or_tty->print_cr(" [from_start .. from_end): " + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, + from_start, + from_end, + pointer_delta(from_end, from_start, sizeof(char))); + gclog_or_tty->print_cr(" [ to_start .. to_end): " + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, + to_start, + to_end, + pointer_delta( to_end, to_start, sizeof(char))); + } + } else { + // Eden, to, from + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr(" Eden, to, from:"); + } + + // To space gets priority over eden resizing. Note that we position + // to space as if we were able to resize from space, even though from + // space is not modified. + // Giving eden priority was tried and gave poorer performance. + to_end = (char*)pointer_delta(_virtual_space->high(), + (char*)requested_survivor_size, + sizeof(char)); + to_end = MIN2(to_end, from_start); + to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size, + sizeof(char)); + // if the space sizes are to be increased by several times then + // 'to_start' will point beyond the young generation. In this case + // 'to_start' should be adjusted. + to_start = MAX2(to_start, eden_start + alignment); + + // Compute how big eden can be, then adjust end. + // See comments above on calculating eden_end. + size_t eden_size; + if (maintain_minimum) { + eden_size = pointer_delta(to_start, eden_start, sizeof(char)); + } else { + eden_size = MIN2(requested_eden_size, + pointer_delta(to_start, eden_start, sizeof(char))); + } + eden_end = eden_start + eden_size; + assert(eden_end >= eden_start, "addition overflowed") + + // Could choose to not let eden shrink + // to_start = MAX2(to_start, eden_end); + + // Don't let eden shrink down to 0 or less. + eden_end = MAX2(eden_end, eden_start + alignment); + to_start = MAX2(to_start, eden_end); + + if (PrintAdaptiveSizePolicy && Verbose) { + gclog_or_tty->print_cr(" [eden_start .. eden_end): " + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, + eden_start, + eden_end, + pointer_delta(eden_end, eden_start, sizeof(char))); + gclog_or_tty->print_cr(" [ to_start .. to_end): " + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, + to_start, + to_end, + pointer_delta( to_end, to_start, sizeof(char))); + gclog_or_tty->print_cr(" [from_start .. from_end): " + "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, + from_start, + from_end, + pointer_delta(from_end, from_start, sizeof(char))); + } + } + + + guarantee((HeapWord*)from_start <= from_space()->bottom(), + "from start moved to the right"); + guarantee((HeapWord*)from_end >= from_space()->top(), + "from end moved into live data"); + assert(is_object_aligned((intptr_t)eden_start), "checking alignment"); + assert(is_object_aligned((intptr_t)from_start), "checking alignment"); + assert(is_object_aligned((intptr_t)to_start), "checking alignment"); + + MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end); + MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end); + MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end); + + // Let's make sure the call to initialize doesn't reset "top"! + HeapWord* old_from_top = from_space()->top(); + + // For PrintAdaptiveSizePolicy block below + size_t old_from = from_space()->capacity_in_bytes(); + size_t old_to = to_space()->capacity_in_bytes(); + + eden_space()->initialize(edenMR, true); + to_space()->initialize(toMR , true); + from_space()->initialize(fromMR, false); // Note, not cleared! + + assert(from_space()->top() == old_from_top, "from top changed!"); + + if (PrintAdaptiveSizePolicy) { + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); + + gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: " + "collection: %d " + "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> " + "(" SIZE_FORMAT ", " SIZE_FORMAT ") ", + heap->total_collections(), + old_from, old_to, + from_space()->capacity_in_bytes(), + to_space()->capacity_in_bytes()); + gclog_or_tty->cr(); + } +} + +void PSYoungGen::swap_spaces() { + MutableSpace* s = from_space(); + _from_space = to_space(); + _to_space = s; + + // Now update the decorators. + PSMarkSweepDecorator* md = from_mark_sweep(); + _from_mark_sweep = to_mark_sweep(); + _to_mark_sweep = md; + + assert(from_mark_sweep()->space() == from_space(), "Sanity"); + assert(to_mark_sweep()->space() == to_space(), "Sanity"); +} + +size_t PSYoungGen::capacity_in_bytes() const { + return eden_space()->capacity_in_bytes() + + from_space()->capacity_in_bytes(); // to_space() is only used during scavenge +} + + +size_t PSYoungGen::used_in_bytes() const { + return eden_space()->used_in_bytes() + + from_space()->used_in_bytes(); // to_space() is only used during scavenge +} + + +size_t PSYoungGen::free_in_bytes() const { + return eden_space()->free_in_bytes() + + from_space()->free_in_bytes(); // to_space() is only used during scavenge +} + +size_t PSYoungGen::capacity_in_words() const { + return eden_space()->capacity_in_words() + + from_space()->capacity_in_words(); // to_space() is only used during scavenge +} + + +size_t PSYoungGen::used_in_words() const { + return eden_space()->used_in_words() + + from_space()->used_in_words(); // to_space() is only used during scavenge +} + + +size_t PSYoungGen::free_in_words() const { + return eden_space()->free_in_words() + + from_space()->free_in_words(); // to_space() is only used during scavenge +} + +void PSYoungGen::object_iterate(ObjectClosure* blk) { + eden_space()->object_iterate(blk); + from_space()->object_iterate(blk); + to_space()->object_iterate(blk); +} + +void PSYoungGen::precompact() { + eden_mark_sweep()->precompact(); + from_mark_sweep()->precompact(); + to_mark_sweep()->precompact(); +} + +void PSYoungGen::adjust_pointers() { + eden_mark_sweep()->adjust_pointers(); + from_mark_sweep()->adjust_pointers(); + to_mark_sweep()->adjust_pointers(); +} + +void PSYoungGen::compact() { + eden_mark_sweep()->compact(ZapUnusedHeapArea); + from_mark_sweep()->compact(ZapUnusedHeapArea); + // Mark sweep stores preserved markOops in to space, don't disturb! + to_mark_sweep()->compact(false); +} + +void PSYoungGen::move_and_update(ParCompactionManager* cm) { + PSParallelCompact::move_and_update(cm, PSParallelCompact::eden_space_id); + PSParallelCompact::move_and_update(cm, PSParallelCompact::from_space_id); + PSParallelCompact::move_and_update(cm, PSParallelCompact::to_space_id); +} + +void PSYoungGen::print() const { print_on(tty); } +void PSYoungGen::print_on(outputStream* st) const { + st->print(" %-15s", "PSYoungGen"); + if (PrintGCDetails && Verbose) { + st->print(" total " SIZE_FORMAT ", used " SIZE_FORMAT, + capacity_in_bytes(), used_in_bytes()); + } else { + st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K", + capacity_in_bytes()/K, used_in_bytes()/K); + } + _virtual_space->print_space_boundaries_on(st); + st->print(" eden"); eden_space()->print_on(st); + st->print(" from"); from_space()->print_on(st); + st->print(" to "); to_space()->print_on(st); +} + +void PSYoungGen::print_used_change(size_t prev_used) const { + gclog_or_tty->print(" [%s:", name()); + gclog_or_tty->print(" " SIZE_FORMAT "K" + "->" SIZE_FORMAT "K" + "(" SIZE_FORMAT "K)", + prev_used / K, used_in_bytes() / K, + capacity_in_bytes() / K); + gclog_or_tty->print("]"); +} + +size_t PSYoungGen::available_for_expansion() { + ShouldNotReachHere(); + return 0; +} + +size_t PSYoungGen::available_for_contraction() { + ShouldNotReachHere(); + return 0; +} + +size_t PSYoungGen::available_to_min_gen() { + assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant"); + return virtual_space()->committed_size() - min_gen_size(); +} + +// This method assumes that from-space has live data and that +// any shrinkage of the young gen is limited by location of +// from-space. +size_t PSYoungGen::available_to_live() { + size_t delta_in_survivor = 0; + ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); + const size_t space_alignment = heap->intra_generation_alignment(); + const size_t gen_alignment = heap->young_gen_alignment(); + + MutableSpace* space_shrinking = NULL; + if (from_space()->end() > to_space()->end()) { + space_shrinking = from_space(); + } else { + space_shrinking = to_space(); + } + + // Include any space that is committed but not included in + // the survivor spaces. + assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(), + "Survivor space beyond high end"); + size_t unused_committed = pointer_delta(virtual_space()->high(), + space_shrinking->end(), sizeof(char)); + + if (space_shrinking->is_empty()) { + // Don't let the space shrink to 0 + assert(space_shrinking->capacity_in_bytes() >= space_alignment, + "Space is too small"); + delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment; + } else { + delta_in_survivor = pointer_delta(space_shrinking->end(), + space_shrinking->top(), + sizeof(char)); + } + + size_t delta_in_bytes = unused_committed + delta_in_survivor; + delta_in_bytes = align_size_down(delta_in_bytes, gen_alignment); + return delta_in_bytes; +} + +// Return the number of bytes available for resizing down the young +// generation. This is the minimum of +// input "bytes" +// bytes to the minimum young gen size +// bytes to the size currently being used + some small extra +size_t PSYoungGen::limit_gen_shrink(size_t bytes) { + // Allow shrinkage into the current eden but keep eden large enough + // to maintain the minimum young gen size + bytes = MIN3(bytes, available_to_min_gen(), available_to_live()); + return align_size_down(bytes, virtual_space()->alignment()); +} + +void PSYoungGen::reset_after_change() { + ShouldNotReachHere(); +} + +void PSYoungGen::reset_survivors_after_shrink() { + _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(), + (HeapWord*)virtual_space()->high_boundary()); + PSScavenge::reference_processor()->set_span(_reserved); + + MutableSpace* space_shrinking = NULL; + if (from_space()->end() > to_space()->end()) { + space_shrinking = from_space(); + } else { + space_shrinking = to_space(); + } + + HeapWord* new_end = (HeapWord*)virtual_space()->high(); + assert(new_end >= space_shrinking->bottom(), "Shrink was too large"); + // Was there a shrink of the survivor space? + if (new_end < space_shrinking->end()) { + MemRegion mr(space_shrinking->bottom(), new_end); + space_shrinking->initialize(mr, false /* clear */); + } +} + +// This method currently does not expect to expand into eden (i.e., +// the virtual space boundaries is expected to be consistent +// with the eden boundaries.. +void PSYoungGen::post_resize() { + assert_locked_or_safepoint(Heap_lock); + assert((eden_space()->bottom() < to_space()->bottom()) && + (eden_space()->bottom() < from_space()->bottom()), + "Eden is assumed to be below the survivor spaces"); + + MemRegion cmr((HeapWord*)virtual_space()->low(), + (HeapWord*)virtual_space()->high()); + Universe::heap()->barrier_set()->resize_covered_region(cmr); + space_invariants(); +} + + + +void PSYoungGen::update_counters() { + if (UsePerfData) { + _eden_counters->update_all(); + _from_counters->update_all(); + _to_counters->update_all(); + _gen_counters->update_all(); + } +} + +void PSYoungGen::verify(bool allow_dirty) { + eden_space()->verify(allow_dirty); + from_space()->verify(allow_dirty); + to_space()->verify(allow_dirty); +}