| /* |
| * Copyright (c) 2001, 2014, 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" |
| |
| PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
| |
| PSYoungGen::PSYoungGen(size_t initial_size, |
| size_t min_size, |
| size_t max_size) : |
| _init_gen_size(initial_size), |
| _min_gen_size(min_size), |
| _max_gen_size(max_size) |
| {} |
| |
| void PSYoungGen::initialize_virtual_space(ReservedSpace rs, size_t alignment) { |
| assert(_init_gen_size != 0, "Should have a finite size"); |
| _virtual_space = new PSVirtualSpace(rs, alignment); |
| if (!virtual_space()->expand_by(_init_gen_size)) { |
| vm_exit_during_initialization("Could not reserve enough space for " |
| "object heap"); |
| } |
| } |
| |
| void PSYoungGen::initialize(ReservedSpace rs, size_t alignment) { |
| initialize_virtual_space(rs, alignment); |
| initialize_work(); |
| } |
| |
| void PSYoungGen::initialize_work() { |
| |
| _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(), |
| (HeapWord*)virtual_space()->high_boundary()); |
| |
| MemRegion cmr((HeapWord*)virtual_space()->low(), |
| (HeapWord*)virtual_space()->high()); |
| Universe::heap()->barrier_set()->resize_covered_region(cmr); |
| |
| if (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, _virtual_space); |
| |
| // Compute maximum space sizes for performance counters |
| ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::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 reachs its maximum size. At this point, |
| // the size of a survivor space is max_survivor_size. |
| max_eden_size = size - 2 * max_survivor_size; |
| } |
| |
| _eden_counters = new SpaceCounters("eden", 0, max_eden_size, _eden_space, |
| _gen_counters); |
| _from_counters = new SpaceCounters("s0", 1, max_survivor_size, _from_space, |
| _gen_counters); |
| _to_counters = new SpaceCounters("s1", 2, max_survivor_size, _to_space, |
| _gen_counters); |
| |
| compute_initial_space_boundaries(); |
| } |
| |
| void PSYoungGen::compute_initial_space_boundaries() { |
| ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
| assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
| |
| // Compute sizes |
| size_t alignment = heap->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*)Universe::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 disired survivor sizes are desired goals and may |
| // exceed the total generation size. |
| |
| assert(min_gen_size() <= orig_size && orig_size <= max_size(), "just checking"); |
| |
| // Adjust new generation size |
| const size_t eden_plus_survivors = |
| align_size_up(eden_size + 2 * survivor_size, alignment); |
| size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_size()), |
| min_gen_size()); |
| assert(desired_size <= max_size(), "just checking"); |
| |
| if (desired_size > orig_size) { |
| // Grow the generation |
| size_t change = desired_size - orig_size; |
| assert(change % alignment == 0, "just checking"); |
| 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 ")", |
| s1->bottom(), s1->end(), s1MR.start(), s1MR.end()); |
| gclog_or_tty->print_cr(" Mangle before: [" PTR_FORMAT ", " |
| PTR_FORMAT ") Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")", |
| delta1_left.start(), delta1_left.end(), delta1_right.start(), |
| delta1_right.end()); |
| |
| // s2 |
| gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") " |
| "New region: [" PTR_FORMAT ", " PTR_FORMAT ")", |
| s2->bottom(), s2->end(), s2MR.start(), s2MR.end()); |
| gclog_or_tty->print_cr(" Mangle before: [" PTR_FORMAT ", " |
| PTR_FORMAT ") Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")", |
| delta2_left.start(), delta2_left.end(), delta2_right.start(), |
| 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, |
| eden_space()->bottom(), |
| eden_space()->end(), |
| pointer_delta(eden_space()->end(), |
| eden_space()->bottom(), |
| sizeof(char))); |
| gclog_or_tty->print_cr(" from: [" PTR_FORMAT ".." PTR_FORMAT ") " |
| SIZE_FORMAT, |
| from_space()->bottom(), |
| from_space()->end(), |
| pointer_delta(from_space()->end(), |
| from_space()->bottom(), |
| sizeof(char))); |
| gclog_or_tty->print_cr(" to: [" PTR_FORMAT ".." PTR_FORMAT ") " |
| SIZE_FORMAT, |
| to_space()->bottom(), |
| to_space()->end(), |
| pointer_delta( to_space()->end(), |
| to_space()->bottom(), |
| sizeof(char))); |
| } |
| |
| // There's nothing to do if the new sizes are the same as the current |
| if (requested_survivor_size == to_space()->capacity_in_bytes() && |
| requested_survivor_size == from_space()->capacity_in_bytes() && |
| requested_eden_size == eden_space()->capacity_in_bytes()) { |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr(" capacities are the right sizes, returning"); |
| } |
| return; |
| } |
| |
| char* eden_start = (char*)eden_space()->bottom(); |
| char* eden_end = (char*)eden_space()->end(); |
| char* from_start = (char*)from_space()->bottom(); |
| char* from_end = (char*)from_space()->end(); |
| char* to_start = (char*)to_space()->bottom(); |
| char* to_end = (char*)to_space()->end(); |
| |
| ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap(); |
| const size_t alignment = heap->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()) { |
| assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
| |
| // Calculate the minimum offset possible for from_end |
| size_t from_size = pointer_delta(from_space()->top(), from_start, sizeof(char)); |
| |
| // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME! |
| if (from_size == 0) { |
| from_size = alignment; |
| } else { |
| from_size = align_size_up(from_size, alignment); |
| } |
| |
| from_end = from_start + from_size; |
| assert(from_end > from_start, "addition overflow or from_size problem"); |
| |
| guarantee(from_end <= (char*)from_space()->end(), "from_end moved to the right"); |
| |
| // Now update to_start with the new from_end |
| to_start = MAX2(from_end, to_start); |
| } |
| |
| guarantee(to_start != to_end, "to space is zero sized"); |
| |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr(" [eden_start .. eden_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| eden_start, |
| eden_end, |
| pointer_delta(eden_end, eden_start, sizeof(char))); |
| gclog_or_tty->print_cr(" [from_start .. from_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| from_start, |
| from_end, |
| pointer_delta(from_end, from_start, sizeof(char))); |
| gclog_or_tty->print_cr(" [ to_start .. to_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| to_start, |
| to_end, |
| pointer_delta( to_end, to_start, sizeof(char))); |
| } |
| } else { |
| // Eden, to, from |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr(" Eden, to, from:"); |
| } |
| |
| // To space gets priority over eden resizing. Note that we position |
| // to space as if we were able to resize from space, even though from |
| // space is not modified. |
| // Giving eden priority was tried and gave poorer performance. |
| to_end = (char*)pointer_delta(virtual_space()->high(), |
| (char*)requested_survivor_size, |
| sizeof(char)); |
| to_end = MIN2(to_end, from_start); |
| to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size, |
| sizeof(char)); |
| // if the space sizes are to be increased by several times then |
| // 'to_start' will point beyond the young generation. In this case |
| // 'to_start' should be adjusted. |
| to_start = MAX2(to_start, eden_start + alignment); |
| |
| // Compute how big eden can be, then adjust end. |
| // See comments above on calculating eden_end. |
| size_t eden_size; |
| if (maintain_minimum) { |
| eden_size = pointer_delta(to_start, eden_start, sizeof(char)); |
| } else { |
| eden_size = MIN2(requested_eden_size, |
| pointer_delta(to_start, eden_start, sizeof(char))); |
| } |
| eden_end = eden_start + eden_size; |
| assert(eden_end >= eden_start, "addition overflowed"); |
| |
| // Could choose to not let eden shrink |
| // to_start = MAX2(to_start, eden_end); |
| |
| // Don't let eden shrink down to 0 or less. |
| eden_end = MAX2(eden_end, eden_start + alignment); |
| to_start = MAX2(to_start, eden_end); |
| |
| if (PrintAdaptiveSizePolicy && Verbose) { |
| gclog_or_tty->print_cr(" [eden_start .. eden_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| eden_start, |
| eden_end, |
| pointer_delta(eden_end, eden_start, sizeof(char))); |
| gclog_or_tty->print_cr(" [ to_start .. to_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| to_start, |
| to_end, |
| pointer_delta( to_end, to_start, sizeof(char))); |
| gclog_or_tty->print_cr(" [from_start .. from_end): " |
| "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT, |
| from_start, |
| from_end, |
| pointer_delta(from_end, from_start, sizeof(char))); |
| } |
| } |
| |
| |
| guarantee((HeapWord*)from_start <= from_space()->bottom(), |
| "from start moved to the right"); |
| guarantee((HeapWord*)from_end >= from_space()->top(), |
| "from end moved into live data"); |
| assert(is_object_aligned((intptr_t)eden_start), "checking alignment"); |
| assert(is_object_aligned((intptr_t)from_start), "checking alignment"); |
| assert(is_object_aligned((intptr_t)to_start), "checking alignment"); |
| |
| MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end); |
| MemRegion toMR ((HeapWord*)to_start, (HeapWord*)to_end); |
| MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end); |
| |
| // Let's make sure the call to initialize doesn't reset "top"! |
| HeapWord* old_from_top = from_space()->top(); |
| |
| // For PrintAdaptiveSizePolicy block below |
| size_t old_from = from_space()->capacity_in_bytes(); |
| size_t old_to = to_space()->capacity_in_bytes(); |
| |
| 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*)Universe::heap(); |
| assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity"); |
| |
| gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: " |
| "collection: %d " |
| "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> " |
| "(" SIZE_FORMAT ", " SIZE_FORMAT ") ", |
| heap->total_collections(), |
| old_from, old_to, |
| from_space()->capacity_in_bytes(), |
| to_space()->capacity_in_bytes()); |
| gclog_or_tty->cr(); |
| } |
| } |
| |
| void PSYoungGen::swap_spaces() { |
| MutableSpace* s = from_space(); |
| _from_space = to_space(); |
| _to_space = s; |
| |
| // Now update the decorators. |
| PSMarkSweepDecorator* md = from_mark_sweep(); |
| _from_mark_sweep = to_mark_sweep(); |
| _to_mark_sweep = md; |
| |
| assert(from_mark_sweep()->space() == from_space(), "Sanity"); |
| assert(to_mark_sweep()->space() == to_space(), "Sanity"); |
| } |
| |
| size_t PSYoungGen::capacity_in_bytes() const { |
| return eden_space()->capacity_in_bytes() |
| + from_space()->capacity_in_bytes(); // to_space() is only used during scavenge |
| } |
| |
| |
| size_t PSYoungGen::used_in_bytes() const { |
| return eden_space()->used_in_bytes() |
| + from_space()->used_in_bytes(); // to_space() is only used during scavenge |
| } |
| |
| |
| size_t PSYoungGen::free_in_bytes() const { |
| return eden_space()->free_in_bytes() |
| + from_space()->free_in_bytes(); // to_space() is only used during scavenge |
| } |
| |
| size_t PSYoungGen::capacity_in_words() const { |
| return eden_space()->capacity_in_words() |
| + from_space()->capacity_in_words(); // to_space() is only used during scavenge |
| } |
| |
| |
| size_t PSYoungGen::used_in_words() const { |
| return eden_space()->used_in_words() |
| + from_space()->used_in_words(); // to_space() is only used during scavenge |
| } |
| |
| |
| size_t PSYoungGen::free_in_words() const { |
| return eden_space()->free_in_words() |
| + from_space()->free_in_words(); // to_space() is only used during scavenge |
| } |
| |
| void PSYoungGen::object_iterate(ObjectClosure* blk) { |
| eden_space()->object_iterate(blk); |
| from_space()->object_iterate(blk); |
| to_space()->object_iterate(blk); |
| } |
| |
| void PSYoungGen::precompact() { |
| eden_mark_sweep()->precompact(); |
| from_mark_sweep()->precompact(); |
| to_mark_sweep()->precompact(); |
| } |
| |
| void PSYoungGen::adjust_pointers() { |
| eden_mark_sweep()->adjust_pointers(); |
| from_mark_sweep()->adjust_pointers(); |
| to_mark_sweep()->adjust_pointers(); |
| } |
| |
| void PSYoungGen::compact() { |
| eden_mark_sweep()->compact(ZapUnusedHeapArea); |
| from_mark_sweep()->compact(ZapUnusedHeapArea); |
| // Mark sweep stores preserved markOops in to space, don't disturb! |
| to_mark_sweep()->compact(false); |
| } |
| |
| void PSYoungGen::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*)Universe::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()); |
| Universe::heap()->barrier_set()->resize_covered_region(cmr); |
| space_invariants(); |
| } |
| |
| |
| |
| void PSYoungGen::update_counters() { |
| if (UsePerfData) { |
| _eden_counters->update_all(); |
| _from_counters->update_all(); |
| _to_counters->update_all(); |
| _gen_counters->update_all(); |
| } |
| } |
| |
| void PSYoungGen::verify() { |
| 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 |
