xref: /aosp_15_r20/external/pigweed/pw_allocator/public/pw_allocator/pool.h (revision 61c4878ac05f98d0ceed94b57d316916de578985)
1 // Copyright 2024 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 #include <cstdint>
18 
19 #include "pw_allocator/capability.h"
20 #include "pw_allocator/deallocator.h"
21 #include "pw_allocator/layout.h"
22 #include "pw_bytes/span.h"
23 #include "pw_result/result.h"
24 
25 namespace pw::allocator {
26 
27 /// Abstract interface for fixed-layout memory allocation.
28 ///
29 /// The interface makes no guarantees about its implementation. Consumers of the
30 /// generic interface must not make any assumptions around allocator behavior,
31 /// thread safety, or performance.
32 class Pool : public Deallocator {
33  public:
Pool(const Capabilities & capabilities,const Layout & layout)34   constexpr Pool(const Capabilities& capabilities, const Layout& layout)
35       : Deallocator(capabilities), layout_(layout) {}
36 
layout()37   const Layout& layout() const { return layout_; }
38 
39   /// Returns a chunk of memory with this object's fixed layout.
40   ///
41   /// Like `pw::allocator::Allocate`, returns null if memory is exhausted.
42   ///
43   /// @retval The allocated memory.
Allocate()44   void* Allocate() { return DoAllocate(); }
45 
46  private:
47   /// Virtual `Allocate` function that can be overridden by derived classes.
48   virtual void* DoAllocate() = 0;
49 
50   const Layout layout_;
51 };
52 
53 }  // namespace pw::allocator
54