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/*
* 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 "gc_implementation/g1/g1Allocator.hpp"
#include "gc_implementation/g1/g1CollectedHeap.hpp"
#include "gc_implementation/g1/g1CollectorPolicy.hpp"
#include "gc_implementation/g1/heapRegion.inline.hpp"
#include "gc_implementation/g1/heapRegionSet.inline.hpp"
void G1DefaultAllocator::init_mutator_alloc_region() {
assert(_mutator_alloc_region.get() == NULL, "pre-condition");
_mutator_alloc_region.init();
}
void G1DefaultAllocator::release_mutator_alloc_region() {
_mutator_alloc_region.release();
assert(_mutator_alloc_region.get() == NULL, "post-condition");
}
void G1Allocator::reuse_retained_old_region(EvacuationInfo& evacuation_info,
OldGCAllocRegion* old,
HeapRegion** retained_old) {
HeapRegion* retained_region = *retained_old;
*retained_old = NULL;
// We will discard the current GC alloc region if:
// a) it's in the collection set (it can happen!),
// b) it's already full (no point in using it),
// c) it's empty (this means that it was emptied during
// a cleanup and it should be on the free list now), or
// d) it's humongous (this means that it was emptied
// during a cleanup and was added to the free list, but
// has been subsequently used to allocate a humongous
// object that may be less than the region size).
if (retained_region != NULL &&
!retained_region->in_collection_set() &&
!(retained_region->top() == retained_region->end()) &&
!retained_region->is_empty() &&
!retained_region->isHumongous()) {
retained_region->record_timestamp();
// The retained region was added to the old region set when it was
// retired. We have to remove it now, since we don't allow regions
// we allocate to in the region sets. We'll re-add it later, when
// it's retired again.
_g1h->_old_set.remove(retained_region);
bool during_im = _g1h->g1_policy()->during_initial_mark_pause();
retained_region->note_start_of_copying(during_im);
old->set(retained_region);
_g1h->_hr_printer.reuse(retained_region);
evacuation_info.set_alloc_regions_used_before(retained_region->used());
}
}
void G1DefaultAllocator::init_gc_alloc_regions(EvacuationInfo& evacuation_info) {
assert_at_safepoint(true /* should_be_vm_thread */);
_survivor_gc_alloc_region.init();
_old_gc_alloc_region.init();
reuse_retained_old_region(evacuation_info,
&_old_gc_alloc_region,
&_retained_old_gc_alloc_region);
}
void G1DefaultAllocator::release_gc_alloc_regions(uint no_of_gc_workers, EvacuationInfo& evacuation_info) {
AllocationContext_t context = AllocationContext::current();
evacuation_info.set_allocation_regions(survivor_gc_alloc_region(context)->count() +
old_gc_alloc_region(context)->count());
survivor_gc_alloc_region(context)->release();
// If we have an old GC alloc region to release, we'll save it in
// _retained_old_gc_alloc_region. If we don't
// _retained_old_gc_alloc_region will become NULL. This is what we
// want either way so no reason to check explicitly for either
// condition.
_retained_old_gc_alloc_region = old_gc_alloc_region(context)->release();
if (_retained_old_gc_alloc_region != NULL) {
_retained_old_gc_alloc_region->record_retained_region();
}
if (ResizePLAB) {
_g1h->_survivor_plab_stats.adjust_desired_plab_sz(no_of_gc_workers);
_g1h->_old_plab_stats.adjust_desired_plab_sz(no_of_gc_workers);
}
}
void G1DefaultAllocator::abandon_gc_alloc_regions() {
assert(survivor_gc_alloc_region(AllocationContext::current())->get() == NULL, "pre-condition");
assert(old_gc_alloc_region(AllocationContext::current())->get() == NULL, "pre-condition");
_retained_old_gc_alloc_region = NULL;
}
G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
ParGCAllocBuffer(gclab_word_size), _retired(true) { }
HeapWord* G1ParGCAllocator::allocate_direct_or_new_plab(InCSetState dest,
size_t word_sz,
AllocationContext_t context) {
size_t gclab_word_size = _g1h->desired_plab_sz(dest);
if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
G1ParGCAllocBuffer* alloc_buf = alloc_buffer(dest, context);
add_to_alloc_buffer_waste(alloc_buf->words_remaining());
alloc_buf->retire(false /* end_of_gc */, false /* retain */);
HeapWord* buf = _g1h->par_allocate_during_gc(dest, gclab_word_size, context);
if (buf == NULL) {
return NULL; // Let caller handle allocation failure.
}
// Otherwise.
alloc_buf->set_word_size(gclab_word_size);
alloc_buf->set_buf(buf);
HeapWord* const obj = alloc_buf->allocate(word_sz);
assert(obj != NULL, "buffer was definitely big enough...");
return obj;
} else {
return _g1h->par_allocate_during_gc(dest, word_sz, context);
}
}
G1DefaultParGCAllocator::G1DefaultParGCAllocator(G1CollectedHeap* g1h) :
G1ParGCAllocator(g1h),
_surviving_alloc_buffer(g1h->desired_plab_sz(InCSetState::Young)),
_tenured_alloc_buffer(g1h->desired_plab_sz(InCSetState::Old)) {
for (uint state = 0; state < InCSetState::Num; state++) {
_alloc_buffers[state] = NULL;
}
_alloc_buffers[InCSetState::Young] = &_surviving_alloc_buffer;
_alloc_buffers[InCSetState::Old] = &_tenured_alloc_buffer;
}
void G1DefaultParGCAllocator::retire_alloc_buffers() {
for (uint state = 0; state < InCSetState::Num; state++) {
G1ParGCAllocBuffer* const buf = _alloc_buffers[state];
if (buf != NULL) {
add_to_alloc_buffer_waste(buf->words_remaining());
buf->flush_stats_and_retire(_g1h->alloc_buffer_stats(state),
true /* end_of_gc */,
false /* retain */);
}
}
}
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