xref: /aosp_15_r20/external/pigweed/pw_allocator/public/pw_allocator/freelist_heap.h (revision 61c4878ac05f98d0ceed94b57d316916de578985)
1 // Copyright 2020 The Pigweed Authors
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not
4 // use this file except in compliance with the License. You may obtain a copy of
5 // the License at
6 //
7 //     https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
12 // License for the specific language governing permissions and limitations under
13 // the License.
14 #pragma once
15 
16 #include <cstddef>
17 
18 #include "pw_allocator/bucket_allocator.h"
19 #include "pw_assert/assert.h"
20 #include "pw_bytes/span.h"
21 #include "pw_preprocessor/compiler.h"
22 
23 namespace pw::allocator {
24 
25 /// Legacy interface to BucketAllocator.
26 ///
27 /// This interface is deprecated, and is only maintained for compatibility
28 /// reasons. New projects should use ``BucketAllocator``.
29 template <size_t kNumBuckets = 6>
30 class FreeListHeapBuffer {
31  public:
FreeListHeapBuffer(ByteSpan region)32   explicit FreeListHeapBuffer(ByteSpan region) : allocator_(region) {}
33 
Allocate(size_t size)34   void* Allocate(size_t size) { return allocator_.Allocate(Layout(size)); }
35 
Free(void * ptr)36   void Free(void* ptr) { allocator_.Deallocate(ptr); }
37 
Realloc(void * ptr,size_t size)38   void* Realloc(void* ptr, size_t size) {
39     return allocator_.Reallocate(ptr, Layout(size));
40   }
41 
Calloc(size_t num,size_t size)42   void* Calloc(size_t num, size_t size) {
43     PW_ASSERT(!PW_MUL_OVERFLOW(num, size, &size));
44     void* ptr = allocator_.Allocate(Layout(size));
45     if (ptr == nullptr) {
46       return nullptr;
47     }
48     std::memset(ptr, 0, size);
49     return ptr;
50   }
51 
52  private:
53   using BlockType = BucketBlock<>;
54   static constexpr size_t kMinChunkSize = 16;
55   BucketAllocator<BlockType, kMinChunkSize, kNumBuckets> allocator_;
56 };
57 
58 }  // namespace pw::allocator
59