63 lines
1.1 KiB
C++
63 lines
1.1 KiB
C++
#pragma once
|
|
|
|
#include <cassert>
|
|
#include <cstddef>
|
|
#include <cstdint>
|
|
|
|
#include "iAllocator.h"
|
|
|
|
|
|
namespace gj {
|
|
|
|
|
|
class StackAllocator : public iAllocator {
|
|
public:
|
|
using iAllocator::Alloc;
|
|
using iAllocator::MakeUnique;
|
|
|
|
StackAllocator() = delete;
|
|
StackAllocator(StackAllocator&&) = delete;
|
|
StackAllocator(const StackAllocator&) = delete;
|
|
|
|
StackAllocator& operator=(StackAllocator&&) = delete;
|
|
StackAllocator& operator=(const StackAllocator&) = delete;
|
|
|
|
StackAllocator(void* ptr, const size_t size) :
|
|
begin_(static_cast<uint8_t*>(ptr)),
|
|
end_ (begin_+size),
|
|
next_ (begin_) {
|
|
}
|
|
~StackAllocator() {
|
|
assert(refcnt_ == 0);
|
|
}
|
|
|
|
void* Alloc(const size_t size) override {
|
|
const size_t aligned_size = ((size >> 3) + !!(size & 0b111)) << 3;
|
|
|
|
void* ret = next_;
|
|
next_ += aligned_size;
|
|
if (next_ >= end_) {
|
|
return nullptr;
|
|
}
|
|
++refcnt_;
|
|
return ret;
|
|
}
|
|
void Free(void* ptr) override {
|
|
if (!ptr) return;
|
|
|
|
assert(refcnt_);
|
|
if (--refcnt_ == 0) {
|
|
next_ = begin_;
|
|
}
|
|
}
|
|
|
|
private:
|
|
uint8_t* const begin_;
|
|
uint8_t* const end_;
|
|
uint8_t* next_;
|
|
|
|
size_t refcnt_ = 0;
|
|
};
|
|
|
|
|
|
} |