blob: 3ac6302cfbe5071d1b9fd26ee5a6c886bda81c4e [file] [log] [blame]
/*
* Copyright 2016 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/fixed_no_free_allocator.h"
#include <algorithm>
#include "nb/pointer_arithmetic.h"
#include "starboard/log.h"
namespace nb {
FixedNoFreeAllocator::FixedNoFreeAllocator(void* memory_start,
std::size_t memory_size)
: memory_start_(memory_start),
memory_end_(AsPointer(AsInteger(memory_start) + memory_size)) {
next_memory_ = memory_start_;
}
void FixedNoFreeAllocator::Free(void* memory) {
// Nothing to do here besides ensure that the freed memory belongs to us.
if (memory < memory_start_ || memory >= memory_end_) {
SB_NOTREACHED() << "Invalid block to free: |memory| is " << memory
<< ", start is " << memory_start_ << ", and end is "
<< memory_end_;
}
}
std::size_t FixedNoFreeAllocator::GetCapacity() const {
return AsInteger(memory_end_) - AsInteger(memory_start_);
}
std::size_t FixedNoFreeAllocator::GetAllocated() const {
return AsInteger(next_memory_) - AsInteger(memory_start_);
}
void FixedNoFreeAllocator::PrintAllocations() const {
SB_NOTIMPLEMENTED();
}
void* FixedNoFreeAllocator::Allocate(std::size_t* size,
std::size_t alignment,
bool align_pointer) {
*size = std::max<std::size_t>(*size, 1);
// Find the next aligned memory available.
uint8_t* aligned_next_memory =
AsPointer(AlignUp(AsInteger(next_memory_), alignment));
if (aligned_next_memory + *size < aligned_next_memory) {
// "aligned_next_memory + size" overflows.
return NULL;
}
if (aligned_next_memory + *size > memory_end_) {
// We don't have enough memory available to make this allocation.
return NULL;
}
if (!align_pointer) {
*size += AsInteger(aligned_next_memory) - AsInteger(next_memory_);
}
void* memory_pointer = align_pointer ? aligned_next_memory : next_memory_;
next_memory_ = aligned_next_memory + *size;
return memory_pointer;
}
} // namespace nb