/* * Copyright (c) 2001, 2015, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "gc/parallel/mutableNUMASpace.hpp" #include "gc/parallel/parallelScavengeHeap.hpp" #include "gc/parallel/psMarkSweepDecorator.hpp" #include "gc/parallel/psScavenge.hpp" #include "gc/parallel/psYoungGen.hpp" #include "gc/shared/gcUtil.hpp" #include "gc/shared/spaceDecorator.hpp" #include "logging/log.hpp" #include "oops/oop.inline.hpp" #include "runtime/java.hpp" 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()); ParallelScavengeHeap::heap()->barrier_set()->resize_covered_region(cmr); if (ZapUnusedHeapArea) { // Mangle newly committed space immediately because it // can be done here more simply that after the new // spaces have been computed. SpaceMangler::mangle_region(cmr); } if (UseNUMA) { _eden_space = new MutableNUMASpace(virtual_space()->alignment()); } else { _eden_space = new MutableSpace(virtual_space()->alignment()); } _from_space = new MutableSpace(virtual_space()->alignment()); _to_space = new MutableSpace(virtual_space()->alignment()); 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, _min_gen_size, _max_gen_size, _virtual_space); // Compute maximum space sizes for performance counters ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); size_t alignment = heap->space_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 reaches 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::heap(); // Compute sizes size_t alignment = heap->space_alignment(); size_t size = virtual_space()->committed_size(); assert(size >= 3 * alignment, "Young space is not large enough for eden + 2 survivors"); 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, ZapUnusedHeapArea); to_space()->initialize(to_mr , true, ZapUnusedHeapArea); from_space()->initialize(from_mr, true, ZapUnusedHeapArea); } #ifndef PRODUCT void PSYoungGen::space_invariants() { ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); const size_t alignment = heap->space_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(); log_trace(gc, ergo)("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 desired 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"); HeapWord* prev_high = (HeapWord*) virtual_space()->high(); if (!virtual_space()->expand_by(change)) { return false; // Error if we fail to resize! } if (ZapUnusedHeapArea) { // Mangle newly committed space immediately because it // can be done here more simply that after the new // spaces have been computed. HeapWord* new_high = (HeapWord*) virtual_space()->high(); MemRegion mangle_region(prev_high, new_high); SpaceMangler::mangle_region(mangle_region); } 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 (orig_size == gen_size_limit()) { log_trace(gc)("PSYoung generation size at maximum: " SIZE_FORMAT "K", orig_size/K); } else if (orig_size == min_gen_size()) { log_trace(gc)("PSYoung generation size at minium: " SIZE_FORMAT "K", orig_size/K); } } if (size_changed) { post_resize(); log_trace(gc)("PSYoung generation size changed: " SIZE_FORMAT "K->" SIZE_FORMAT "K", orig_size/K, virtual_space()->committed_size()/K); } guarantee(eden_plus_survivors <= virtual_space()->committed_size() || virtual_space()->committed_size() == max_size(), "Sanity"); return true; } #ifndef PRODUCT // In the numa case eden is not mangled so a survivor space // moving into a region previously occupied by a survivor // may find an unmangled region. Also in the PS case eden // to-space and from-space may not touch (i.e., there may be // gaps between them due to movement while resizing the // spaces). Those gaps must be mangled. void PSYoungGen::mangle_survivors(MutableSpace* s1, MemRegion s1MR, MutableSpace* s2, MemRegion s2MR) { // Check eden and gap between eden and from-space, in deciding // what to mangle in from-space. Check the gap between from-space // and to-space when deciding what to mangle. // // +--------+ +----+ +---+ // | eden | |s1 | |s2 | // +--------+ +----+ +---+ // +-------+ +-----+ // |s1MR | |s2MR | // +-------+ +-----+ // All of survivor-space is properly mangled so find the // upper bound on the mangling for any portion above current s1. HeapWord* delta_end = MIN2(s1->bottom(), s1MR.end()); MemRegion delta1_left; if (s1MR.start() < delta_end) { delta1_left = MemRegion(s1MR.start(), delta_end); s1->mangle_region(delta1_left); } // Find any portion to the right of the current s1. HeapWord* delta_start = MAX2(s1->end(), s1MR.start()); MemRegion delta1_right; if (delta_start < s1MR.end()) { delta1_right = MemRegion(delta_start, s1MR.end()); s1->mangle_region(delta1_right); } // Similarly for the second survivor space except that // any of the new region that overlaps with the current // region of the first survivor space has already been // mangled. delta_end = MIN2(s2->bottom(), s2MR.end()); delta_start = MAX2(s2MR.start(), s1->end()); MemRegion delta2_left; if (s2MR.start() < delta_end) { delta2_left = MemRegion(s2MR.start(), delta_end); s2->mangle_region(delta2_left); } delta_start = MAX2(s2->end(), s2MR.start()); MemRegion delta2_right; if (delta_start < s2MR.end()) { s2->mangle_region(delta2_right); } // s1 log_develop(gc)("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") " "New region: [" PTR_FORMAT ", " PTR_FORMAT ")", p2i(s1->bottom()), p2i(s1->end()), p2i(s1MR.start()), p2i(s1MR.end())); log_develop(gc)(" Mangle before: [" PTR_FORMAT ", " PTR_FORMAT ") Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")", p2i(delta1_left.start()), p2i(delta1_left.end()), p2i(delta1_right.start()), p2i(delta1_right.end())); // s2 log_develop(gc)("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") " "New region: [" PTR_FORMAT ", " PTR_FORMAT ")", p2i(s2->bottom()), p2i(s2->end()), p2i(s2MR.start()), p2i(s2MR.end())); log_develop(gc)(" Mangle before: [" PTR_FORMAT ", " PTR_FORMAT ") Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")", p2i(delta2_left.start()), p2i(delta2_left.end()), p2i(delta2_right.start()), p2i(delta2_right.end())); } #endif // NOT PRODUCT 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; } log_trace(gc, ergo)("PSYoungGen::resize_spaces(requested_eden_size: " SIZE_FORMAT ", requested_survivor_size: " SIZE_FORMAT ")", requested_eden_size, requested_survivor_size); log_trace(gc, ergo)(" eden: [" PTR_FORMAT ".." PTR_FORMAT ") " SIZE_FORMAT, p2i(eden_space()->bottom()), p2i(eden_space()->end()), pointer_delta(eden_space()->end(), eden_space()->bottom(), sizeof(char))); log_trace(gc, ergo)(" from: [" PTR_FORMAT ".." PTR_FORMAT ") " SIZE_FORMAT, p2i(from_space()->bottom()), p2i(from_space()->end()), pointer_delta(from_space()->end(), from_space()->bottom(), sizeof(char))); log_trace(gc, ergo)(" to: [" PTR_FORMAT ".." PTR_FORMAT ") " SIZE_FORMAT, p2i(to_space()->bottom()), p2i(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()) { log_trace(gc, ergo)(" 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::heap(); const size_t alignment = heap->space_alignment(); const bool maintain_minimum = (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size(); bool eden_from_to_order = from_start < to_start; // Check whether from space is below to space if (eden_from_to_order) { // Eden, from, to eden_from_to_order = true; log_trace(gc, ergo)(" 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()) { // 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"); log_trace(gc, ergo)(" [eden_start .. eden_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, p2i(eden_start), p2i(eden_end), pointer_delta(eden_end, eden_start, sizeof(char))); log_trace(gc, ergo)(" [from_start .. from_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, p2i(from_start), p2i(from_end), pointer_delta(from_end, from_start, sizeof(char))); log_trace(gc, ergo)(" [ to_start .. to_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, p2i(to_start), p2i(to_end), pointer_delta( to_end, to_start, sizeof(char))); } else { // Eden, to, from log_trace(gc, ergo)(" 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); log_trace(gc, ergo)(" [eden_start .. eden_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, p2i(eden_start), p2i(eden_end), pointer_delta(eden_end, eden_start, sizeof(char))); log_trace(gc, ergo)(" [ to_start .. to_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, p2i(to_start), p2i(to_end), pointer_delta( to_end, to_start, sizeof(char))); log_trace(gc, ergo)(" [from_start .. from_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, p2i(from_start), p2i(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 logging block below size_t old_from = from_space()->capacity_in_bytes(); size_t old_to = to_space()->capacity_in_bytes(); if (ZapUnusedHeapArea) { // NUMA is a special case because a numa space is not mangled // in order to not prematurely bind its address to memory to // the wrong memory (i.e., don't want the GC thread to first // touch the memory). The survivor spaces are not numa // spaces and are mangled. if (UseNUMA) { if (eden_from_to_order) { mangle_survivors(from_space(), fromMR, to_space(), toMR); } else { mangle_survivors(to_space(), toMR, from_space(), fromMR); } } // If not mangling the spaces, do some checking to verify that // the spaces are already mangled. // The spaces should be correctly mangled at this point so // do some checking here. Note that they are not being mangled // in the calls to initialize(). // Must check mangling before the spaces are reshaped. Otherwise, // the bottom or end of one space may have moved into an area // covered by another space and a failure of the check may // not correctly indicate which space is not properly mangled. HeapWord* limit = (HeapWord*) virtual_space()->high(); eden_space()->check_mangled_unused_area(limit); from_space()->check_mangled_unused_area(limit); to_space()->check_mangled_unused_area(limit); } // When an existing space is being initialized, it is not // mangled because the space has been previously mangled. eden_space()->initialize(edenMR, SpaceDecorator::Clear, SpaceDecorator::DontMangle); to_space()->initialize(toMR, SpaceDecorator::Clear, SpaceDecorator::DontMangle); from_space()->initialize(fromMR, SpaceDecorator::DontClear, SpaceDecorator::DontMangle); assert(from_space()->top() == old_from_top, "from top changed!"); log_trace(gc, ergo)("AdaptiveSizePolicy::survivor space sizes: collection: %d (" SIZE_FORMAT ", " SIZE_FORMAT ") -> (" SIZE_FORMAT ", " SIZE_FORMAT ") ", ParallelScavengeHeap::heap()->total_collections(), old_from, old_to, from_space()->capacity_in_bytes(), to_space()->capacity_in_bytes()); } 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::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); } // Note that a space is not printed before the [NAME: void PSYoungGen::print_used_change(size_t prev_used) const { log_info(gc, heap)("%s: " SIZE_FORMAT "K->" SIZE_FORMAT "K(" SIZE_FORMAT "K)", name(), prev_used / K, used_in_bytes() / K, capacity_in_bytes() / K); } 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::heap(); const size_t space_alignment = heap->space_alignment(); const size_t gen_alignment = heap->generation_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, SpaceDecorator::DontClear, SpaceDecorator::Mangle); } } // 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()); ParallelScavengeHeap::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() { eden_space()->verify(); from_space()->verify(); to_space()->verify(); } #ifndef PRODUCT void PSYoungGen::record_spaces_top() { assert(ZapUnusedHeapArea, "Not mangling unused space"); eden_space()->set_top_for_allocations(); from_space()->set_top_for_allocations(); to_space()->set_top_for_allocations(); } #endif