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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_slow(GCAllocPurpose purpose, size_t word_sz, AllocationContext_t context) {

   HeapWord* obj = NULL;

   size_t gclab_word_size = _g1h->desired_plab_sz(purpose);

   if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {

     G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose, 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(purpose, 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);

     obj = alloc_buf->allocate(word_sz);

     assert(obj != NULL, "buffer was definitely big enough...");

   } else {

     obj = _g1h->par_allocate_during_gc(purpose, word_sz, context);

   }

   return obj;

 }

 G1DefaultParGCAllocator::G1DefaultParGCAllocator(G1CollectedHeap* g1h) :

             G1ParGCAllocator(g1h),

             _surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),

             _tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)) {

   _alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;

   _alloc_buffers[GCAllocForTenured]  = &_tenured_alloc_buffer;

 }

 void G1DefaultParGCAllocator::retire_alloc_buffers() {

   for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {

     size_t waste = _alloc_buffers[ap]->words_remaining();

     add_to_alloc_buffer_waste(waste);

     _alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap),

                                                true /* end_of_gc */,

                                                false /* retain */);

   }

 }