--- old/src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp 2015-05-13 13:57:33.870902970 +0200 +++ /dev/null 2015-03-18 17:10:38.111854831 +0100 @@ -1,953 +0,0 @@ -/* - * 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_implementation/parallelScavenge/parallelScavengeHeap.hpp" -#include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp" -#include "gc_implementation/parallelScavenge/psScavenge.hpp" -#include "gc_implementation/parallelScavenge/psYoungGen.hpp" -#include "gc_implementation/shared/gcUtil.hpp" -#include "gc_implementation/shared/mutableNUMASpace.hpp" -#include "gc_implementation/shared/spaceDecorator.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(); - - 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 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 (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; -} - -#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); - } - - if (TraceZapUnusedHeapArea) { - // s1 - gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") " - "New region: [" PTR_FORMAT ", " PTR_FORMAT ")", - p2i(s1->bottom()), p2i(s1->end()), - p2i(s1MR.start()), p2i(s1MR.end())); - gclog_or_tty->print_cr(" 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 - gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") " - "New region: [" PTR_FORMAT ", " PTR_FORMAT ")", - p2i(s2->bottom()), p2i(s2->end()), - p2i(s2MR.start()), p2i(s2MR.end())); - gclog_or_tty->print_cr(" 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; - } - - 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, - p2i(eden_space()->bottom()), - p2i(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, - p2i(from_space()->bottom()), - p2i(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, - 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()) { - 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::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; - 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()) { - // 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, - p2i(eden_start), - p2i(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, - p2i(from_start), - p2i(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, - p2i(to_start), - p2i(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, - p2i(eden_start), - p2i(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, - p2i(to_start), - p2i(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, - 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 PrintAdaptiveSizePolicy 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!"); - - if (PrintAdaptiveSizePolicy) { - ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); - 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::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 { - 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::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 --- /dev/null 2015-03-18 17:10:38.111854831 +0100 +++ new/src/share/vm/gc/parallel/psYoungGen.cpp 2015-05-13 13:57:33.687895376 +0200 @@ -0,0 +1,953 @@ +/* + * 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 "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(); + + 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 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 (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; +} + +#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); + } + + if (TraceZapUnusedHeapArea) { + // s1 + gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") " + "New region: [" PTR_FORMAT ", " PTR_FORMAT ")", + p2i(s1->bottom()), p2i(s1->end()), + p2i(s1MR.start()), p2i(s1MR.end())); + gclog_or_tty->print_cr(" 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 + gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") " + "New region: [" PTR_FORMAT ", " PTR_FORMAT ")", + p2i(s2->bottom()), p2i(s2->end()), + p2i(s2MR.start()), p2i(s2MR.end())); + gclog_or_tty->print_cr(" 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; + } + + 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, + p2i(eden_space()->bottom()), + p2i(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, + p2i(from_space()->bottom()), + p2i(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, + 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()) { + 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::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; + 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()) { + // 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, + p2i(eden_start), + p2i(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, + p2i(from_start), + p2i(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, + p2i(to_start), + p2i(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, + p2i(eden_start), + p2i(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, + p2i(to_start), + p2i(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, + 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 PrintAdaptiveSizePolicy 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!"); + + if (PrintAdaptiveSizePolicy) { + ParallelScavengeHeap* heap = ParallelScavengeHeap::heap(); + 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::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 { + 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::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