jdk-sandbox: comparison src/hotspot/share/gc/parallel/psYoungGen.cpp

equal deleted inserted replaced

-:4ebc2e2fb97c
+:71c04702a3d5
+/*
+* Copyright (c) 2001, 2015, Oracle and/or its affiliates. All rights reserved.
+* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+*
+* This code is free software; you can redistribute it and/or modify it
+* under the terms of the GNU General Public License version 2 only, as
+* published by the Free Software Foundation.
+*
+* This code is distributed in the hope that it will be useful, but WITHOUT
+* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+* version 2 for more details (a copy is included in the LICENSE file that
+* accompanied this code).
+*
+* You should have received a copy of the GNU General Public License version
+* 2 along with this work; if not, write to the Free Software Foundation,
+* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+*
+* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+* or visit www.oracle.com if you need additional information or have any
+* questions.
+*
+*/
+#include "precompiled.hpp"
+#include "gc/parallel/mutableNUMASpace.hpp"
+#include "gc/parallel/parallelScavengeHeap.hpp"
+#include "gc/parallel/psMarkSweepDecorator.hpp"
+#include "gc/parallel/psScavenge.hpp"
+#include "gc/parallel/psYoungGen.hpp"
+#include "gc/shared/gcUtil.hpp"
+#include "gc/shared/spaceDecorator.hpp"
+#include "logging/log.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/java.hpp"
+#include "utilities/align.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_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_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_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(eden_start), "checking alignment");
+assert(is_object_aligned(to_start),   "checking alignment");
+assert(is_object_aligned(from_start), "checking alignment");
+MemRegion eden_mr((HeapWord*)eden_start, (HeapWord*)to_start);
+MemRegion to_mr  ((HeapWord*)to_start, (HeapWord*)from_start);
+MemRegion from_mr((HeapWord*)from_start, (HeapWord*)from_end);
+eden_space()->initialize(eden_mr, true, ZapUnusedHeapArea);
+to_space()->initialize(to_mr  , true, ZapUnusedHeapArea);
+from_space()->initialize(from_mr, true, ZapUnusedHeapArea);
+}
+#ifndef PRODUCT
+void PSYoungGen::space_invariants() {
+ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
+const size_t alignment = heap->space_alignment();
+// Currently, our eden size cannot shrink to zero
+guarantee(eden_space()->capacity_in_bytes() >= alignment, "eden too small");
+guarantee(from_space()->capacity_in_bytes() >= alignment, "from too small");
+guarantee(to_space()->capacity_in_bytes() >= alignment, "to too small");
+// Relationship of spaces to each other
+char* eden_start = (char*)eden_space()->bottom();
+char* eden_end   = (char*)eden_space()->end();
+char* from_start = (char*)from_space()->bottom();
+char* from_end   = (char*)from_space()->end();
+char* to_start   = (char*)to_space()->bottom();
+char* to_end     = (char*)to_space()->end();
+guarantee(eden_start >= virtual_space()->low(), "eden bottom");
+guarantee(eden_start < eden_end, "eden space consistency");
+guarantee(from_start < from_end, "from space consistency");
+guarantee(to_start < to_end, "to space consistency");
+// Check whether from space is below to space
+if (from_start < to_start) {
+// Eden, from, to
+guarantee(eden_end <= from_start, "eden/from boundary");
+guarantee(from_end <= to_start,   "from/to boundary");
+guarantee(to_end <= virtual_space()->high(), "to end");
+} else {
+// Eden, to, from
+guarantee(eden_end <= to_start, "eden/to boundary");
+guarantee(to_end <= from_start, "to/from boundary");
+guarantee(from_end <= virtual_space()->high(), "from end");
+}
+// More checks that the virtual space is consistent with the spaces
+assert(virtual_space()->committed_size() >=
+(eden_space()->capacity_in_bytes() +
+to_space()->capacity_in_bytes() +
+from_space()->capacity_in_bytes()), "Committed size is inconsistent");
+assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
+"Space invariant");
+char* eden_top = (char*)eden_space()->top();
+char* from_top = (char*)from_space()->top();
+char* to_top = (char*)to_space()->top();
+assert(eden_top <= virtual_space()->high(), "eden top");
+assert(from_top <= virtual_space()->high(), "from top");
+assert(to_top <= virtual_space()->high(), "to top");
+virtual_space()->verify();
+}
+#endif
+void PSYoungGen::resize(size_t eden_size, size_t survivor_size) {
+// Resize the generation if needed. If the generation resize
+// reports false, do not attempt to resize the spaces.
+if (resize_generation(eden_size, survivor_size)) {
+// Then we lay out the spaces inside the generation
+resize_spaces(eden_size, survivor_size);
+space_invariants();
+log_trace(gc, ergo)("Young generation size: "
+"desired eden: " SIZE_FORMAT " survivor: " SIZE_FORMAT
+" used: " SIZE_FORMAT " capacity: " SIZE_FORMAT
+" gen limits: " SIZE_FORMAT " / " SIZE_FORMAT,
+eden_size, survivor_size, used_in_bytes(), capacity_in_bytes(),
+_max_gen_size, min_gen_size());
+}
+}
+bool PSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
+const size_t alignment = virtual_space()->alignment();
+size_t orig_size = virtual_space()->committed_size();
+bool size_changed = false;
+// There used to be this guarantee there.
+// guarantee ((eden_size + 2*survivor_size)  <= _max_gen_size, "incorrect input arguments");
+// Code below forces this requirement.  In addition the desired eden
+// size and desired survivor sizes are desired goals and may
+// exceed the total generation size.
+assert(min_gen_size() <= orig_size && orig_size <= max_size(), "just checking");
+// Adjust new generation size
+const size_t eden_plus_survivors =
+align_up(eden_size + 2 * survivor_size, alignment);
+size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_size()),
+min_gen_size());
+assert(desired_size <= max_size(), "just checking");
+if (desired_size > orig_size) {
+// Grow the generation
+size_t change = desired_size - orig_size;
+assert(change % alignment == 0, "just checking");
+HeapWord* prev_high = (HeapWord*) virtual_space()->high();
+if (!virtual_space()->expand_by(change)) {
+return false; // Error if we fail to resize!
+}
+if (ZapUnusedHeapArea) {
+// Mangle newly committed space immediately because it
+// can be done here more simply that after the new
+// spaces have been computed.
+HeapWord* new_high = (HeapWord*) virtual_space()->high();
+MemRegion mangle_region(prev_high, new_high);
+SpaceMangler::mangle_region(mangle_region);
+}
+size_changed = true;
+} else if (desired_size < orig_size) {
+size_t desired_change = orig_size - desired_size;
+assert(desired_change % alignment == 0, "just checking");
+desired_change = limit_gen_shrink(desired_change);
+if (desired_change > 0) {
+virtual_space()->shrink_by(desired_change);
+reset_survivors_after_shrink();
+size_changed = true;
+}
+} else {
+if (orig_size == gen_size_limit()) {
+log_trace(gc)("PSYoung generation size at maximum: " SIZE_FORMAT "K", orig_size/K);
+} else if (orig_size == min_gen_size()) {
+log_trace(gc)("PSYoung generation size at minium: " SIZE_FORMAT "K", orig_size/K);
+}
+}
+if (size_changed) {
+post_resize();
+log_trace(gc)("PSYoung generation size changed: " SIZE_FORMAT "K->" SIZE_FORMAT "K",
+orig_size/K, virtual_space()->committed_size()/K);
+}
+guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
+virtual_space()->committed_size() == max_size(), "Sanity");
+return true;
+}
+#ifndef PRODUCT
+// In the numa case eden is not mangled so a survivor space
+// moving into a region previously occupied by a survivor
+// may find an unmangled region.  Also in the PS case eden
+// to-space and from-space may not touch (i.e., there may be
+// gaps between them due to movement while resizing the
+// spaces).  Those gaps must be mangled.
+void PSYoungGen::mangle_survivors(MutableSpace* s1,
+MemRegion s1MR,
+MutableSpace* s2,
+MemRegion s2MR) {
+// Check eden and gap between eden and from-space, in deciding
+// what to mangle in from-space.  Check the gap between from-space
+// and to-space when deciding what to mangle.
+//
+//      +--------+   +----+    +---+
+//      | eden   |   |s1  |    |s2 |
+//      +--------+   +----+    +---+
+//                 +-------+ +-----+
+//                 |s1MR   | |s2MR |
+//                 +-------+ +-----+
+// All of survivor-space is properly mangled so find the
+// upper bound on the mangling for any portion above current s1.
+HeapWord* delta_end = MIN2(s1->bottom(), s1MR.end());
+MemRegion delta1_left;
+if (s1MR.start() < delta_end) {
+delta1_left = MemRegion(s1MR.start(), delta_end);
+s1->mangle_region(delta1_left);
+}
+// Find any portion to the right of the current s1.
+HeapWord* delta_start = MAX2(s1->end(), s1MR.start());
+MemRegion delta1_right;
+if (delta_start < s1MR.end()) {
+delta1_right = MemRegion(delta_start, s1MR.end());
+s1->mangle_region(delta1_right);
+}
+// Similarly for the second survivor space except that
+// any of the new region that overlaps with the current
+// region of the first survivor space has already been
+// mangled.
+delta_end = MIN2(s2->bottom(), s2MR.end());
+delta_start = MAX2(s2MR.start(), s1->end());
+MemRegion delta2_left;
+if (s2MR.start() < delta_end) {
+delta2_left = MemRegion(s2MR.start(), delta_end);
+s2->mangle_region(delta2_left);
+}
+delta_start = MAX2(s2->end(), s2MR.start());
+MemRegion delta2_right;
+if (delta_start < s2MR.end()) {
+s2->mangle_region(delta2_right);
+}
+// s1
+log_develop_trace(gc)("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
+"New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
+p2i(s1->bottom()), p2i(s1->end()),
+p2i(s1MR.start()), p2i(s1MR.end()));
+log_develop_trace(gc)("    Mangle before: [" PTR_FORMAT ", "
+PTR_FORMAT ")  Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
+p2i(delta1_left.start()), p2i(delta1_left.end()),
+p2i(delta1_right.start()), p2i(delta1_right.end()));
+// s2
+log_develop_trace(gc)("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
+"New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
+p2i(s2->bottom()), p2i(s2->end()),
+p2i(s2MR.start()), p2i(s2MR.end()));
+log_develop_trace(gc)("    Mangle before: [" PTR_FORMAT ", "
+PTR_FORMAT ")  Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
+p2i(delta2_left.start()), p2i(delta2_left.end()),
+p2i(delta2_right.start()), p2i(delta2_right.end()));
+}
+#endif // NOT PRODUCT
+void PSYoungGen::resize_spaces(size_t requested_eden_size,
+size_t requested_survivor_size) {
+assert(UseAdaptiveSizePolicy, "sanity check");
+assert(requested_eden_size > 0  && requested_survivor_size > 0,
+"just checking");
+// We require eden and to space to be empty
+if ((!eden_space()->is_empty()) || (!to_space()->is_empty())) {
+return;
+}
+log_trace(gc, ergo)("PSYoungGen::resize_spaces(requested_eden_size: " SIZE_FORMAT ", requested_survivor_size: " SIZE_FORMAT ")",
+requested_eden_size, requested_survivor_size);
+log_trace(gc, ergo)("    eden: [" PTR_FORMAT ".." PTR_FORMAT ") " SIZE_FORMAT,
+p2i(eden_space()->bottom()),
+p2i(eden_space()->end()),
+pointer_delta(eden_space()->end(),
+eden_space()->bottom(),
+sizeof(char)));
+log_trace(gc, ergo)("    from: [" PTR_FORMAT ".." PTR_FORMAT ") " SIZE_FORMAT,
+p2i(from_space()->bottom()),
+p2i(from_space()->end()),
+pointer_delta(from_space()->end(),
+from_space()->bottom(),
+sizeof(char)));
+log_trace(gc, ergo)("      to: [" PTR_FORMAT ".." PTR_FORMAT ") " SIZE_FORMAT,
+p2i(to_space()->bottom()),
+p2i(to_space()->end()),
+pointer_delta(  to_space()->end(),
+to_space()->bottom(),
+sizeof(char)));
+// There's nothing to do if the new sizes are the same as the current
+if (requested_survivor_size == to_space()->capacity_in_bytes() &&
+requested_survivor_size == from_space()->capacity_in_bytes() &&
+requested_eden_size == eden_space()->capacity_in_bytes()) {
+log_trace(gc, ergo)("    capacities are the right sizes, returning");
+return;
+}
+char* eden_start = (char*)eden_space()->bottom();
+char* eden_end   = (char*)eden_space()->end();
+char* from_start = (char*)from_space()->bottom();
+char* from_end   = (char*)from_space()->end();
+char* to_start   = (char*)to_space()->bottom();
+char* to_end     = (char*)to_space()->end();
+ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
+const size_t alignment = heap->space_alignment();
+const bool maintain_minimum =
+(requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
+bool eden_from_to_order = from_start < to_start;
+// Check whether from space is below to space
+if (eden_from_to_order) {
+// Eden, from, to
+eden_from_to_order = true;
+log_trace(gc, ergo)("  Eden, from, to:");
+// Set eden
+// "requested_eden_size" is a goal for the size of eden
+// and may not be attainable.  "eden_size" below is
+// calculated based on the location of from-space and
+// the goal for the size of eden.  from-space is
+// fixed in place because it contains live data.
+// The calculation is done this way to avoid 32bit
+// overflow (i.e., eden_start + requested_eden_size
+// may too large for representation in 32bits).
+size_t eden_size;
+if (maintain_minimum) {
+// Only make eden larger than the requested size if
+// the minimum size of the generation has to be maintained.
+// This could be done in general but policy at a higher
+// level is determining a requested size for eden and that
+// should be honored unless there is a fundamental reason.
+eden_size = pointer_delta(from_start,
+eden_start,
+sizeof(char));
+} else {
+eden_size = MIN2(requested_eden_size,
+pointer_delta(from_start, eden_start, sizeof(char)));
+}
+eden_end = eden_start + eden_size;
+assert(eden_end >= eden_start, "addition overflowed");
+// To may resize into from space as long as it is clear of live data.
+// From space must remain page aligned, though, so we need to do some
+// extra calculations.
+// First calculate an optimal to-space
+to_end   = (char*)virtual_space()->high();
+to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
+sizeof(char));
+// Does the optimal to-space overlap from-space?
+if (to_start < (char*)from_space()->end()) {
+// Calculate the minimum offset possible for from_end
+size_t from_size = pointer_delta(from_space()->top(), from_start, sizeof(char));
+// Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
+if (from_size == 0) {
+from_size = alignment;
+} else {
+from_size = align_up(from_size, alignment);
+}
+from_end = from_start + from_size;
+assert(from_end > from_start, "addition overflow or from_size problem");
+guarantee(from_end <= (char*)from_space()->end(), "from_end moved to the right");
+// Now update to_start with the new from_end
+to_start = MAX2(from_end, to_start);
+}
+guarantee(to_start != to_end, "to space is zero sized");
+log_trace(gc, ergo)("    [eden_start .. eden_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+p2i(eden_start),
+p2i(eden_end),
+pointer_delta(eden_end, eden_start, sizeof(char)));
+log_trace(gc, ergo)("    [from_start .. from_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+p2i(from_start),
+p2i(from_end),
+pointer_delta(from_end, from_start, sizeof(char)));
+log_trace(gc, ergo)("    [  to_start ..   to_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+p2i(to_start),
+p2i(to_end),
+pointer_delta(  to_end,   to_start, sizeof(char)));
+} else {
+// Eden, to, from
+log_trace(gc, ergo)("  Eden, to, from:");
+// To space gets priority over eden resizing. Note that we position
+// to space as if we were able to resize from space, even though from
+// space is not modified.
+// Giving eden priority was tried and gave poorer performance.
+to_end   = (char*)pointer_delta(virtual_space()->high(),
+(char*)requested_survivor_size,
+sizeof(char));
+to_end   = MIN2(to_end, from_start);
+to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
+sizeof(char));
+// if the space sizes are to be increased by several times then
+// 'to_start' will point beyond the young generation. In this case
+// 'to_start' should be adjusted.
+to_start = MAX2(to_start, eden_start + alignment);
+// Compute how big eden can be, then adjust end.
+// See  comments above on calculating eden_end.
+size_t eden_size;
+if (maintain_minimum) {
+eden_size = pointer_delta(to_start, eden_start, sizeof(char));
+} else {
+eden_size = MIN2(requested_eden_size,
+pointer_delta(to_start, eden_start, sizeof(char)));
+}
+eden_end = eden_start + eden_size;
+assert(eden_end >= eden_start, "addition overflowed");
+// Could choose to not let eden shrink
+// to_start = MAX2(to_start, eden_end);
+// Don't let eden shrink down to 0 or less.
+eden_end = MAX2(eden_end, eden_start + alignment);
+to_start = MAX2(to_start, eden_end);
+log_trace(gc, ergo)("    [eden_start .. eden_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+p2i(eden_start),
+p2i(eden_end),
+pointer_delta(eden_end, eden_start, sizeof(char)));
+log_trace(gc, ergo)("    [  to_start ..   to_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+p2i(to_start),
+p2i(to_end),
+pointer_delta(  to_end,   to_start, sizeof(char)));
+log_trace(gc, ergo)("    [from_start .. from_end): [" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
+p2i(from_start),
+p2i(from_end),
+pointer_delta(from_end, from_start, sizeof(char)));
+}
+guarantee((HeapWord*)from_start <= from_space()->bottom(),
+"from start moved to the right");
+guarantee((HeapWord*)from_end >= from_space()->top(),
+"from end moved into live data");
+assert(is_object_aligned(eden_start), "checking alignment");
+assert(is_object_aligned(from_start), "checking alignment");
+assert(is_object_aligned(to_start), "checking alignment");
+MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
+MemRegion toMR  ((HeapWord*)to_start,   (HeapWord*)to_end);
+MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
+// Let's make sure the call to initialize doesn't reset "top"!
+HeapWord* old_from_top = from_space()->top();
+// For logging block  below
+size_t old_from = from_space()->capacity_in_bytes();
+size_t old_to   = to_space()->capacity_in_bytes();
+if (ZapUnusedHeapArea) {
+// NUMA is a special case because a numa space is not mangled
+// in order to not prematurely bind its address to memory to
+// the wrong memory (i.e., don't want the GC thread to first
+// touch the memory).  The survivor spaces are not numa
+// spaces and are mangled.
+if (UseNUMA) {
+if (eden_from_to_order) {
+mangle_survivors(from_space(), fromMR, to_space(), toMR);
+} else {
+mangle_survivors(to_space(), toMR, from_space(), fromMR);
+}
+}
+// If not mangling the spaces, do some checking to verify that
+// the spaces are already mangled.
+// The spaces should be correctly mangled at this point so
+// do some checking here. Note that they are not being mangled
+// in the calls to initialize().
+// Must check mangling before the spaces are reshaped.  Otherwise,
+// the bottom or end of one space may have moved into an area
+// covered by another space and a failure of the check may
+// not correctly indicate which space is not properly mangled.
+HeapWord* limit = (HeapWord*) virtual_space()->high();
+eden_space()->check_mangled_unused_area(limit);
+from_space()->check_mangled_unused_area(limit);
+to_space()->check_mangled_unused_area(limit);
+}
+// When an existing space is being initialized, it is not
+// mangled because the space has been previously mangled.
+eden_space()->initialize(edenMR,
+SpaceDecorator::Clear,
+SpaceDecorator::DontMangle);
+to_space()->initialize(toMR,
+SpaceDecorator::Clear,
+SpaceDecorator::DontMangle);
+from_space()->initialize(fromMR,
+SpaceDecorator::DontClear,
+SpaceDecorator::DontMangle);
+assert(from_space()->top() == old_from_top, "from top changed!");
+log_trace(gc, ergo)("AdaptiveSizePolicy::survivor space sizes: collection: %d (" SIZE_FORMAT ", " SIZE_FORMAT ") -> (" SIZE_FORMAT ", " SIZE_FORMAT ") ",
+ParallelScavengeHeap::heap()->total_collections(),
+old_from, old_to,
+from_space()->capacity_in_bytes(),
+to_space()->capacity_in_bytes());
+}
+void PSYoungGen::swap_spaces() {
+MutableSpace* s    = from_space();
+_from_space        = to_space();
+_to_space          = s;
+// Now update the decorators.
+PSMarkSweepDecorator* md = from_mark_sweep();
+_from_mark_sweep           = to_mark_sweep();
+_to_mark_sweep             = md;
+assert(from_mark_sweep()->space() == from_space(), "Sanity");
+assert(to_mark_sweep()->space() == to_space(), "Sanity");
+}
+size_t PSYoungGen::capacity_in_bytes() const {
+return eden_space()->capacity_in_bytes()
++ from_space()->capacity_in_bytes();  // to_space() is only used during scavenge
+}
+size_t PSYoungGen::used_in_bytes() const {
+return eden_space()->used_in_bytes()
++ from_space()->used_in_bytes();      // to_space() is only used during scavenge
+}
+size_t PSYoungGen::free_in_bytes() const {
+return eden_space()->free_in_bytes()
++ from_space()->free_in_bytes();      // to_space() is only used during scavenge
+}
+size_t PSYoungGen::capacity_in_words() const {
+return eden_space()->capacity_in_words()
++ from_space()->capacity_in_words();  // to_space() is only used during scavenge
+}
+size_t PSYoungGen::used_in_words() const {
+return eden_space()->used_in_words()
++ from_space()->used_in_words();      // to_space() is only used during scavenge
+}
+size_t PSYoungGen::free_in_words() const {
+return eden_space()->free_in_words()
++ from_space()->free_in_words();      // to_space() is only used during scavenge
+}
+void PSYoungGen::object_iterate(ObjectClosure* blk) {
+eden_space()->object_iterate(blk);
+from_space()->object_iterate(blk);
+to_space()->object_iterate(blk);
+}
+void PSYoungGen::precompact() {
+eden_mark_sweep()->precompact();
+from_mark_sweep()->precompact();
+to_mark_sweep()->precompact();
+}
+void PSYoungGen::adjust_pointers() {
+eden_mark_sweep()->adjust_pointers();
+from_mark_sweep()->adjust_pointers();
+to_mark_sweep()->adjust_pointers();
+}
+void PSYoungGen::compact() {
+eden_mark_sweep()->compact(ZapUnusedHeapArea);
+from_mark_sweep()->compact(ZapUnusedHeapArea);
+// Mark sweep stores preserved markOops in to space, don't disturb!
+to_mark_sweep()->compact(false);
+}
+void PSYoungGen::print() const { print_on(tty); }
+void PSYoungGen::print_on(outputStream* st) const {
+st->print(" %-15s", "PSYoungGen");
+st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K",
+capacity_in_bytes()/K, used_in_bytes()/K);
+virtual_space()->print_space_boundaries_on(st);
+st->print("  eden"); eden_space()->print_on(st);
+st->print("  from"); from_space()->print_on(st);
+st->print("  to  "); to_space()->print_on(st);
+}
+// Note that a space is not printed before the [NAME:
+void PSYoungGen::print_used_change(size_t prev_used) const {
+log_info(gc, heap)("%s: "  SIZE_FORMAT "K->" SIZE_FORMAT "K("  SIZE_FORMAT "K)",
+name(), prev_used / K, used_in_bytes() / K, capacity_in_bytes() / K);
+}
+size_t PSYoungGen::available_for_expansion() {
+ShouldNotReachHere();
+return 0;
+}
+size_t PSYoungGen::available_for_contraction() {
+ShouldNotReachHere();
+return 0;
+}
+size_t PSYoungGen::available_to_min_gen() {
+assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant");
+return virtual_space()->committed_size() - min_gen_size();
+}
+// This method assumes that from-space has live data and that
+// any shrinkage of the young gen is limited by location of
+// from-space.
+size_t PSYoungGen::available_to_live() {
+size_t delta_in_survivor = 0;
+ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
+const size_t space_alignment = heap->space_alignment();
+const size_t gen_alignment = heap->generation_alignment();
+MutableSpace* space_shrinking = NULL;
+if (from_space()->end() > to_space()->end()) {
+space_shrinking = from_space();
+} else {
+space_shrinking = to_space();
+}
+// Include any space that is committed but not included in
+// the survivor spaces.
+assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(),
+"Survivor space beyond high end");
+size_t unused_committed = pointer_delta(virtual_space()->high(),
+space_shrinking->end(), sizeof(char));
+if (space_shrinking->is_empty()) {
+// Don't let the space shrink to 0
+assert(space_shrinking->capacity_in_bytes() >= space_alignment,
+"Space is too small");
+delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment;
+} else {
+delta_in_survivor = pointer_delta(space_shrinking->end(),
+space_shrinking->top(),
+sizeof(char));
+}
+size_t delta_in_bytes = unused_committed + delta_in_survivor;
+delta_in_bytes = align_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_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

changeset 47216	71c04702a3d5
parent 46625	edefffab74e2
child 49164	7e958a8ebcd3