blob: dcc412209bcdf742a8081f4ce67f832b4f435bf4 [file] [log] [blame]
// Copyright 2017 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "nb/bidirectional_fit_reuse_allocator.h"
#include <algorithm>
#include "nb/pointer_arithmetic.h"
#include "starboard/common/log.h"
#include "starboard/types.h"
namespace nb {
BidirectionalFitReuseAllocator::BidirectionalFitReuseAllocator(
Allocator* fallback_allocator,
std::size_t initial_capacity,
std::size_t small_allocation_threshold,
std::size_t allocation_increment /*= 0*/,
std::size_t max_capacity /* =0 */
)
: ReuseAllocatorBase(fallback_allocator,
initial_capacity,
allocation_increment,
max_capacity),
small_allocation_threshold_(small_allocation_threshold) {}
ReuseAllocatorBase::FreeBlockSet::iterator
BidirectionalFitReuseAllocator::FindFreeBlock(std::size_t size,
std::size_t alignment,
FreeBlockSet::iterator begin,
FreeBlockSet::iterator end,
bool* allocate_from_front) {
SB_DCHECK(allocate_from_front);
*allocate_from_front = size > small_allocation_threshold_;
if (*allocate_from_front) {
// Start looking through the free list from the front.
for (FreeBlockSet::iterator it = begin; it != end; ++it) {
if (it->CanFullfill(size, alignment)) {
return it;
}
}
}
// Start looking through the free list from the back.
FreeBlockSet::reverse_iterator rbegin(end);
FreeBlockSet::reverse_iterator rend(begin);
for (FreeBlockSet::reverse_iterator it = rbegin; it != rend; ++it) {
if (it->CanFullfill(size, alignment)) {
return --it.base();
}
}
return end;
}
} // namespace nb