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8066780: Split CardGeneration out to its own file

Browse source 
Reviewed-by: kbarrett, tschatzl
This commit is contained in:
Bengt Rutisson 2014-12-10 11:30:46 +01:00
parent 5d868d4e0f
commit ef7d6c3b9d
6 changed files with 354 additions and 296 deletions
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2
hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp
View file

@ -30,8 +30,8 @@
#include "gc_implementation/shared/gcStats.hpp"
#include "gc_implementation/shared/gcWhen.hpp"
#include "gc_implementation/shared/generationCounters.hpp"
#include "memory/cardGeneration.hpp"
#include "memory/freeBlockDictionary.hpp"
#include "memory/generation.hpp"
#include "memory/iterator.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/virtualspace.hpp"

271
hotspot/src/share/vm/memory/cardGeneration.cpp Normal file
View file

@ -0,0 +1,271 @@
/*
* Copyright (c) 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 "memory/blockOffsetTable.inline.hpp"
#include "memory/gcLocker.hpp"
#include "memory/generationSpec.hpp"
#include "memory/genOopClosures.inline.hpp"
#include "memory/genRemSet.hpp"
#include "memory/iterator.hpp"
#include "memory/memRegion.hpp"
#include "memory/space.inline.hpp"
#include "runtime/java.hpp"
CardGeneration::CardGeneration(ReservedSpace rs, size_t initial_byte_size,
int level,
GenRemSet* remset) :
Generation(rs, initial_byte_size, level), _rs(remset),
_shrink_factor(0), _min_heap_delta_bytes(), _capacity_at_prologue(),
_used_at_prologue()
{
HeapWord* start = (HeapWord*)rs.base();
size_t reserved_byte_size = rs.size();
assert((uintptr_t(start) & 3) == 0, "bad alignment");
assert((reserved_byte_size & 3) == 0, "bad alignment");
MemRegion reserved_mr(start, heap_word_size(reserved_byte_size));
_bts = new BlockOffsetSharedArray(reserved_mr,
heap_word_size(initial_byte_size));
MemRegion committed_mr(start, heap_word_size(initial_byte_size));
_rs->resize_covered_region(committed_mr);
if (_bts == NULL)
vm_exit_during_initialization("Could not allocate a BlockOffsetArray");
// Verify that the start and end of this generation is the start of a card.
// If this wasn't true, a single card could span more than on generation,
// which would cause problems when we commit/uncommit memory, and when we
// clear and dirty cards.
guarantee(_rs->is_aligned(reserved_mr.start()), "generation must be card aligned");
if (reserved_mr.end() != Universe::heap()->reserved_region().end()) {
// Don't check at the very end of the heap as we'll assert that we're probing off
// the end if we try.
guarantee(_rs->is_aligned(reserved_mr.end()), "generation must be card aligned");
}
_min_heap_delta_bytes = MinHeapDeltaBytes;
_capacity_at_prologue = initial_byte_size;
_used_at_prologue = 0;
}
bool CardGeneration::expand(size_t bytes, size_t expand_bytes) {
assert_locked_or_safepoint(Heap_lock);
if (bytes == 0) {
return true; // That's what grow_by(0) would return
}
size_t aligned_bytes = ReservedSpace::page_align_size_up(bytes);
if (aligned_bytes == 0){
// The alignment caused the number of bytes to wrap. An expand_by(0) will
// return true with the implication that an expansion was done when it
// was not. A call to expand implies a best effort to expand by "bytes"
// but not a guarantee. Align down to give a best effort. This is likely
// the most that the generation can expand since it has some capacity to
// start with.
aligned_bytes = ReservedSpace::page_align_size_down(bytes);
}
size_t aligned_expand_bytes = ReservedSpace::page_align_size_up(expand_bytes);
bool success = false;
if (aligned_expand_bytes > aligned_bytes) {
success = grow_by(aligned_expand_bytes);
}
if (!success) {
success = grow_by(aligned_bytes);
}
if (!success) {
success = grow_to_reserved();
}
if (PrintGC && Verbose) {
if (success && GC_locker::is_active_and_needs_gc()) {
gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead");
}
}
return success;
}
// No young generation references, clear this generation's cards.
void CardGeneration::clear_remembered_set() {
_rs->clear(reserved());
}
// Objects in this generation may have moved, invalidate this
// generation's cards.
void CardGeneration::invalidate_remembered_set() {
_rs->invalidate(used_region());
}
void CardGeneration::compute_new_size() {
assert(_shrink_factor <= 100, "invalid shrink factor");
size_t current_shrink_factor = _shrink_factor;
_shrink_factor = 0;
// We don't have floating point command-line arguments
// Note: argument processing ensures that MinHeapFreeRatio < 100.
const double minimum_free_percentage = MinHeapFreeRatio / 100.0;
const double maximum_used_percentage = 1.0 - minimum_free_percentage;
// Compute some numbers about the state of the heap.
const size_t used_after_gc = used();
const size_t capacity_after_gc = capacity();
const double min_tmp = used_after_gc / maximum_used_percentage;
size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(max_uintx));
// Don't shrink less than the initial generation size
minimum_desired_capacity = MAX2(minimum_desired_capacity,
spec()->init_size());
assert(used_after_gc <= minimum_desired_capacity, "sanity check");
if (PrintGC && Verbose) {
const size_t free_after_gc = free();
const double free_percentage = ((double)free_after_gc) / capacity_after_gc;
gclog_or_tty->print_cr("TenuredGeneration::compute_new_size: ");
gclog_or_tty->print_cr(" "
" minimum_free_percentage: %6.2f"
" maximum_used_percentage: %6.2f",
minimum_free_percentage,
maximum_used_percentage);
gclog_or_tty->print_cr(" "
" free_after_gc : %6.1fK"
" used_after_gc : %6.1fK"
" capacity_after_gc : %6.1fK",
free_after_gc / (double) K,
used_after_gc / (double) K,
capacity_after_gc / (double) K);
gclog_or_tty->print_cr(" "
" free_percentage: %6.2f",
free_percentage);
}
if (capacity_after_gc < minimum_desired_capacity) {
// If we have less free space than we want then expand
size_t expand_bytes = minimum_desired_capacity - capacity_after_gc;
// Don't expand unless it's significant
if (expand_bytes >= _min_heap_delta_bytes) {
expand(expand_bytes, 0); // safe if expansion fails
}
if (PrintGC && Verbose) {
gclog_or_tty->print_cr(" expanding:"
" minimum_desired_capacity: %6.1fK"
" expand_bytes: %6.1fK"
" _min_heap_delta_bytes: %6.1fK",
minimum_desired_capacity / (double) K,
expand_bytes / (double) K,
_min_heap_delta_bytes / (double) K);
}
return;
}
// No expansion, now see if we want to shrink
size_t shrink_bytes = 0;
// We would never want to shrink more than this
size_t max_shrink_bytes = capacity_after_gc - minimum_desired_capacity;
if (MaxHeapFreeRatio < 100) {
const double maximum_free_percentage = MaxHeapFreeRatio / 100.0;
const double minimum_used_percentage = 1.0 - maximum_free_percentage;
const double max_tmp = used_after_gc / minimum_used_percentage;
size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
maximum_desired_capacity = MAX2(maximum_desired_capacity,
spec()->init_size());
if (PrintGC && Verbose) {
gclog_or_tty->print_cr(" "
" maximum_free_percentage: %6.2f"
" minimum_used_percentage: %6.2f",
maximum_free_percentage,
minimum_used_percentage);
gclog_or_tty->print_cr(" "
" _capacity_at_prologue: %6.1fK"
" minimum_desired_capacity: %6.1fK"
" maximum_desired_capacity: %6.1fK",
_capacity_at_prologue / (double) K,
minimum_desired_capacity / (double) K,
maximum_desired_capacity / (double) K);
}
assert(minimum_desired_capacity <= maximum_desired_capacity,
"sanity check");
if (capacity_after_gc > maximum_desired_capacity) {
// Capacity too large, compute shrinking size
shrink_bytes = capacity_after_gc - maximum_desired_capacity;
// We don't want shrink all the way back to initSize if people call
// System.gc(), because some programs do that between "phases" and then
// we'd just have to grow the heap up again for the next phase. So we
// damp the shrinking: 0% on the first call, 10% on the second call, 40%
// on the third call, and 100% by the fourth call. But if we recompute
// size without shrinking, it goes back to 0%.
shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
if (current_shrink_factor == 0) {
_shrink_factor = 10;
} else {
_shrink_factor = MIN2(current_shrink_factor * 4, (size_t) 100);
}
if (PrintGC && Verbose) {
gclog_or_tty->print_cr(" "
" shrinking:"
" initSize: %.1fK"
" maximum_desired_capacity: %.1fK",
spec()->init_size() / (double) K,
maximum_desired_capacity / (double) K);
gclog_or_tty->print_cr(" "
" shrink_bytes: %.1fK"
" current_shrink_factor: " SIZE_FORMAT
" new shrink factor: " SIZE_FORMAT
" _min_heap_delta_bytes: %.1fK",
shrink_bytes / (double) K,
current_shrink_factor,
_shrink_factor,
_min_heap_delta_bytes / (double) K);
}
}
}
if (capacity_after_gc > _capacity_at_prologue) {
// We might have expanded for promotions, in which case we might want to
// take back that expansion if there's room after GC. That keeps us from
// stretching the heap with promotions when there's plenty of room.
size_t expansion_for_promotion = capacity_after_gc - _capacity_at_prologue;
expansion_for_promotion = MIN2(expansion_for_promotion, max_shrink_bytes);
// We have two shrinking computations, take the largest
shrink_bytes = MAX2(shrink_bytes, expansion_for_promotion);
assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
if (PrintGC && Verbose) {
gclog_or_tty->print_cr(" "
" aggressive shrinking:"
" _capacity_at_prologue: %.1fK"
" capacity_after_gc: %.1fK"
" expansion_for_promotion: %.1fK"
" shrink_bytes: %.1fK",
capacity_after_gc / (double) K,
_capacity_at_prologue / (double) K,
expansion_for_promotion / (double) K,
shrink_bytes / (double) K);
}
}
// Don't shrink unless it's significant
if (shrink_bytes >= _min_heap_delta_bytes) {
shrink(shrink_bytes);
}
}
// Currently nothing to do.
void CardGeneration::prepare_for_verify() {}

81
hotspot/src/share/vm/memory/cardGeneration.hpp Normal file
View file

@ -0,0 +1,81 @@
/*
* Copyright (c) 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.
*
*/
#ifndef SHARE_VM_MEMORY_CARDGENERATION_HPP
#define SHARE_VM_MEMORY_CARDGENERATION_HPP
// Class CardGeneration is a generation that is covered by a card table,
// and uses a card-size block-offset array to implement block_start.
#include "memory/generation.hpp"
class BlockOffsetSharedArray;
class CardGeneration: public Generation {
friend class VMStructs;
protected:
// This is shared with other generations.
GenRemSet* _rs;
// This is local to this generation.
BlockOffsetSharedArray* _bts;
// current shrinking effect: this damps shrinking when the heap gets empty.
size_t _shrink_factor;
size_t _min_heap_delta_bytes; // Minimum amount to expand.
// Some statistics from before gc started.
// These are gathered in the gc_prologue (and should_collect)
// to control growing/shrinking policy in spite of promotions.
size_t _capacity_at_prologue;
size_t _used_at_prologue;
CardGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
GenRemSet* remset);
public:
// Attempt to expand the generation by "bytes". Expand by at a
// minimum "expand_bytes". Return true if some amount (not
// necessarily the full "bytes") was done.
virtual bool expand(size_t bytes, size_t expand_bytes);
// Shrink generation with specified size
virtual void shrink(size_t bytes) = 0;
virtual void compute_new_size();
virtual void clear_remembered_set();
virtual void invalidate_remembered_set();
virtual void prepare_for_verify();
// Grow generation with specified size (returns false if unable to grow)
virtual bool grow_by(size_t bytes) = 0;
// Grow generation to reserved size.
virtual bool grow_to_reserved() = 0;
};
#endif // SHARE_VM_MEMORY_CARDGENERATION_HPP

241
hotspot/src/share/vm/memory/generation.cpp
View file

@ -361,244 +361,3 @@ void Generation::compact() {
sp = sp->next_compaction_space();
}
}
CardGeneration::CardGeneration(ReservedSpace rs, size_t initial_byte_size,
int level,
GenRemSet* remset) :
Generation(rs, initial_byte_size, level), _rs(remset),
_shrink_factor(0), _min_heap_delta_bytes(), _capacity_at_prologue(),
_used_at_prologue()
{
HeapWord* start = (HeapWord*)rs.base();
size_t reserved_byte_size = rs.size();
assert((uintptr_t(start) & 3) == 0, "bad alignment");
assert((reserved_byte_size & 3) == 0, "bad alignment");
MemRegion reserved_mr(start, heap_word_size(reserved_byte_size));
_bts = new BlockOffsetSharedArray(reserved_mr,
heap_word_size(initial_byte_size));
MemRegion committed_mr(start, heap_word_size(initial_byte_size));
_rs->resize_covered_region(committed_mr);
if (_bts == NULL)
vm_exit_during_initialization("Could not allocate a BlockOffsetArray");
// Verify that the start and end of this generation is the start of a card.
// If this wasn't true, a single card could span more than on generation,
// which would cause problems when we commit/uncommit memory, and when we
// clear and dirty cards.
guarantee(_rs->is_aligned(reserved_mr.start()), "generation must be card aligned");
if (reserved_mr.end() != Universe::heap()->reserved_region().end()) {
// Don't check at the very end of the heap as we'll assert that we're probing off
// the end if we try.
guarantee(_rs->is_aligned(reserved_mr.end()), "generation must be card aligned");
}
_min_heap_delta_bytes = MinHeapDeltaBytes;
_capacity_at_prologue = initial_byte_size;
_used_at_prologue = 0;
}
bool CardGeneration::expand(size_t bytes, size_t expand_bytes) {
assert_locked_or_safepoint(Heap_lock);
if (bytes == 0) {
return true; // That's what grow_by(0) would return
}
size_t aligned_bytes = ReservedSpace::page_align_size_up(bytes);
if (aligned_bytes == 0){
// The alignment caused the number of bytes to wrap. An expand_by(0) will
// return true with the implication that an expansion was done when it
// was not. A call to expand implies a best effort to expand by "bytes"
// but not a guarantee. Align down to give a best effort. This is likely
// the most that the generation can expand since it has some capacity to
// start with.
aligned_bytes = ReservedSpace::page_align_size_down(bytes);
}
size_t aligned_expand_bytes = ReservedSpace::page_align_size_up(expand_bytes);
bool success = false;
if (aligned_expand_bytes > aligned_bytes) {
success = grow_by(aligned_expand_bytes);
}
if (!success) {
success = grow_by(aligned_bytes);
}
if (!success) {
success = grow_to_reserved();
}
if (PrintGC && Verbose) {
if (success && GC_locker::is_active_and_needs_gc()) {
gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead");
}
}
return success;
}
// No young generation references, clear this generation's cards.
void CardGeneration::clear_remembered_set() {
_rs->clear(reserved());
}
// Objects in this generation may have moved, invalidate this
// generation's cards.
void CardGeneration::invalidate_remembered_set() {
_rs->invalidate(used_region());
}
void CardGeneration::compute_new_size() {
assert(_shrink_factor <= 100, "invalid shrink factor");
size_t current_shrink_factor = _shrink_factor;
_shrink_factor = 0;
// We don't have floating point command-line arguments
// Note: argument processing ensures that MinHeapFreeRatio < 100.
const double minimum_free_percentage = MinHeapFreeRatio / 100.0;
const double maximum_used_percentage = 1.0 - minimum_free_percentage;
// Compute some numbers about the state of the heap.
const size_t used_after_gc = used();
const size_t capacity_after_gc = capacity();
const double min_tmp = used_after_gc / maximum_used_percentage;
size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(max_uintx));
// Don't shrink less than the initial generation size
minimum_desired_capacity = MAX2(minimum_desired_capacity,
spec()->init_size());
assert(used_after_gc <= minimum_desired_capacity, "sanity check");
if (PrintGC && Verbose) {
const size_t free_after_gc = free();
const double free_percentage = ((double)free_after_gc) / capacity_after_gc;
gclog_or_tty->print_cr("TenuredGeneration::compute_new_size: ");
gclog_or_tty->print_cr(" "
" minimum_free_percentage: %6.2f"
" maximum_used_percentage: %6.2f",
minimum_free_percentage,
maximum_used_percentage);
gclog_or_tty->print_cr(" "
" free_after_gc : %6.1fK"
" used_after_gc : %6.1fK"
" capacity_after_gc : %6.1fK",
free_after_gc / (double) K,
used_after_gc / (double) K,
capacity_after_gc / (double) K);
gclog_or_tty->print_cr(" "
" free_percentage: %6.2f",
free_percentage);
}
if (capacity_after_gc < minimum_desired_capacity) {
// If we have less free space than we want then expand
size_t expand_bytes = minimum_desired_capacity - capacity_after_gc;
// Don't expand unless it's significant
if (expand_bytes >= _min_heap_delta_bytes) {
expand(expand_bytes, 0); // safe if expansion fails
}
if (PrintGC && Verbose) {
gclog_or_tty->print_cr(" expanding:"
" minimum_desired_capacity: %6.1fK"
" expand_bytes: %6.1fK"
" _min_heap_delta_bytes: %6.1fK",
minimum_desired_capacity / (double) K,
expand_bytes / (double) K,
_min_heap_delta_bytes / (double) K);
}
return;
}
// No expansion, now see if we want to shrink
size_t shrink_bytes = 0;
// We would never want to shrink more than this
size_t max_shrink_bytes = capacity_after_gc - minimum_desired_capacity;
if (MaxHeapFreeRatio < 100) {
const double maximum_free_percentage = MaxHeapFreeRatio / 100.0;
const double minimum_used_percentage = 1.0 - maximum_free_percentage;
const double max_tmp = used_after_gc / minimum_used_percentage;
size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
maximum_desired_capacity = MAX2(maximum_desired_capacity,
spec()->init_size());
if (PrintGC && Verbose) {
gclog_or_tty->print_cr(" "
" maximum_free_percentage: %6.2f"
" minimum_used_percentage: %6.2f",
maximum_free_percentage,
minimum_used_percentage);
gclog_or_tty->print_cr(" "
" _capacity_at_prologue: %6.1fK"
" minimum_desired_capacity: %6.1fK"
" maximum_desired_capacity: %6.1fK",
_capacity_at_prologue / (double) K,
minimum_desired_capacity / (double) K,
maximum_desired_capacity / (double) K);
}
assert(minimum_desired_capacity <= maximum_desired_capacity,
"sanity check");
if (capacity_after_gc > maximum_desired_capacity) {
// Capacity too large, compute shrinking size
shrink_bytes = capacity_after_gc - maximum_desired_capacity;
// We don't want shrink all the way back to initSize if people call
// System.gc(), because some programs do that between "phases" and then
// we'd just have to grow the heap up again for the next phase. So we
// damp the shrinking: 0% on the first call, 10% on the second call, 40%
// on the third call, and 100% by the fourth call. But if we recompute
// size without shrinking, it goes back to 0%.
shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
if (current_shrink_factor == 0) {
_shrink_factor = 10;
} else {
_shrink_factor = MIN2(current_shrink_factor * 4, (size_t) 100);
}
if (PrintGC && Verbose) {
gclog_or_tty->print_cr(" "
" shrinking:"
" initSize: %.1fK"
" maximum_desired_capacity: %.1fK",
spec()->init_size() / (double) K,
maximum_desired_capacity / (double) K);
gclog_or_tty->print_cr(" "
" shrink_bytes: %.1fK"
" current_shrink_factor: " SIZE_FORMAT
" new shrink factor: " SIZE_FORMAT
" _min_heap_delta_bytes: %.1fK",
shrink_bytes / (double) K,
current_shrink_factor,
_shrink_factor,
_min_heap_delta_bytes / (double) K);
}
}
}
if (capacity_after_gc > _capacity_at_prologue) {
// We might have expanded for promotions, in which case we might want to
// take back that expansion if there's room after GC. That keeps us from
// stretching the heap with promotions when there's plenty of room.
size_t expansion_for_promotion = capacity_after_gc - _capacity_at_prologue;
expansion_for_promotion = MIN2(expansion_for_promotion, max_shrink_bytes);
// We have two shrinking computations, take the largest
shrink_bytes = MAX2(shrink_bytes, expansion_for_promotion);
assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
if (PrintGC && Verbose) {
gclog_or_tty->print_cr(" "
" aggressive shrinking:"
" _capacity_at_prologue: %.1fK"
" capacity_after_gc: %.1fK"
" expansion_for_promotion: %.1fK"
" shrink_bytes: %.1fK",
capacity_after_gc / (double) K,
_capacity_at_prologue / (double) K,
expansion_for_promotion / (double) K,
shrink_bytes / (double) K);
}
}
// Don't shrink unless it's significant
if (shrink_bytes >= _min_heap_delta_bytes) {
shrink(shrink_bytes);
}
}
// Currently nothing to do.
void CardGeneration::prepare_for_verify() {}

53
hotspot/src/share/vm/memory/generation.hpp
View file

@ -584,57 +584,4 @@ public:
virtual CollectorCounters* counters() { return _gc_counters; }
};
// Class CardGeneration is a generation that is covered by a card table,
// and uses a card-size block-offset array to implement block_start.
// class BlockOffsetArray;
// class BlockOffsetArrayContigSpace;
class BlockOffsetSharedArray;
class CardGeneration: public Generation {
friend class VMStructs;
protected:
// This is shared with other generations.
GenRemSet* _rs;
// This is local to this generation.
BlockOffsetSharedArray* _bts;
// current shrinking effect: this damps shrinking when the heap gets empty.
size_t _shrink_factor;
size_t _min_heap_delta_bytes; // Minimum amount to expand.
// Some statistics from before gc started.
// These are gathered in the gc_prologue (and should_collect)
// to control growing/shrinking policy in spite of promotions.
size_t _capacity_at_prologue;
size_t _used_at_prologue;
CardGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
GenRemSet* remset);
public:
// Attempt to expand the generation by "bytes". Expand by at a
// minimum "expand_bytes". Return true if some amount (not
// necessarily the full "bytes") was done.
virtual bool expand(size_t bytes, size_t expand_bytes);
// Shrink generation with specified size (returns false if unable to shrink)
virtual void shrink(size_t bytes) = 0;
virtual void compute_new_size();
virtual void clear_remembered_set();
virtual void invalidate_remembered_set();
virtual void prepare_for_verify();
// Grow generation with specified size (returns false if unable to grow)
virtual bool grow_by(size_t bytes) = 0;
// Grow generation to reserved size.
virtual bool grow_to_reserved() = 0;
};
#endif // SHARE_VM_MEMORY_GENERATION_HPP

2
hotspot/src/share/vm/memory/tenuredGeneration.hpp
View file

@ -28,7 +28,7 @@
#include "gc_implementation/shared/cSpaceCounters.hpp"
#include "gc_implementation/shared/gcStats.hpp"
#include "gc_implementation/shared/generationCounters.hpp"
#include "memory/generation.hpp"
#include "memory/cardGeneration.hpp"
#include "utilities/macros.hpp"
// TenuredGeneration models the heap containing old (promoted/tenured) objects