ffe59c54cb
At this point we might want to rename allocator files to util_allocator_foo.c so the stay nicely grouped in the folder.
153 lines
3.0 KiB
C++
153 lines
3.0 KiB
C++
/*
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* Copyright 2011-2016 Blender Foundation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef __UTIL_STACK_ALLOCATOR_H__
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#define __UTIL_STACK_ALLOCATOR_H__
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#include <cstddef>
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#include <memory>
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#include "util_debug.h"
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#include "util_types.h"
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CCL_NAMESPACE_BEGIN
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/* Stack allocator for the use with STL. */
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template <int SIZE, typename T>
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class ccl_try_align(16) StackAllocator {
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public:
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typedef size_t size_type;
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typedef ptrdiff_t difference_type;
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typedef T *pointer;
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typedef const T *const_pointer;
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typedef T& reference;
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typedef const T& const_reference;
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typedef T value_type;
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/* Allocator construction/destruction. */
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StackAllocator()
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: pointer_(0) {}
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StackAllocator(const StackAllocator&)
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: pointer_(0) {}
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template <class U>
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StackAllocator(const StackAllocator<SIZE, U>&)
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: pointer_(0) {}
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/* Memory allocation/deallocation. */
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T *allocate(size_t n, const void *hint = 0)
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{
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(void)hint;
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if(pointer_ + n >= SIZE) {
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assert(!"Stack allocator overallocated");
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/* NOTE: This is just a safety feature for the release builds, so
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* we fallback to a less efficient allocation but preventing crash
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* from happening.
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*/
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return (T*)malloc(n * sizeof(T));
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}
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T *mem = &data_[pointer_];
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pointer_ += n;
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return mem;
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}
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void deallocate(T *p, size_t /*n*/)
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{
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if(p == NULL) {
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return;
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}
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if(p < data_ || p >= data_ + SIZE) {
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/* Again this is just a safety feature for the release builds. */
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assert(!"Should never happen");
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free(p);
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return;
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}
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/* We don't support memory free for the stack allocator. */
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}
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/* Address of an reference. */
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T *address(T& x) const
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{
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return &x;
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}
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const T *address(const T& x) const
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{
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return &x;
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}
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/* Object construction/destruction. */
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void construct(T *p, const T& val)
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{
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new ((T *)p) T(val);
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}
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void destroy(T *p)
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{
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p->~T();
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}
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/* Maximum allocation size. */
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size_t max_size() const
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{
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return size_t(-1);
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}
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/* Rebind to other ype of allocator. */
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template <class U>
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struct rebind {
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typedef StackAllocator<SIZE, U> other;
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};
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/* Operators */
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template <class U>
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inline StackAllocator& operator=(const StackAllocator<SIZE, U>&)
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{
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return *this;
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}
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StackAllocator<SIZE, T>& operator=(const StackAllocator&)
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{
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return *this;
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}
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inline bool operator==(StackAllocator const& /*other*/) const
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{
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return true;
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}
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inline bool operator!=(StackAllocator const& other) const
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{
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return !operator==(other);
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}
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private:
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int pointer_;
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T data_[SIZE];
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};
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CCL_NAMESPACE_END
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#endif /* __UTIL_GUARDED_ALLOCATOR_H__ */
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