test_harness.h

// Copyright 2023 The Pigweed Authors
//
// 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
//
//     https://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.
#pragma once
 
#include <cstddef>
#include <variant>
 
#include "pw_allocator/allocator.h"
#include "pw_containers/vector.h"
#include "pw_random/random.h"
 
namespace pw::allocator::test {
 
struct AllocationRequest {
  size_t size = 0;
  size_t alignment = 1;
};
 
struct DeallocationRequest {
  size_t index = 0;
};
 
struct ReallocationRequest {
  size_t index = 0;
  size_t new_size = 0;
};
 
using Request =
    std::variant<AllocationRequest, DeallocationRequest, ReallocationRequest>;
 
size_t AlignmentFromLShift(size_t lshift, size_t size);
 
class TestHarnessGeneric {
 public:
  virtual ~TestHarnessGeneric() = default;
 
  void GenerateRequests(random::RandomGenerator& prng,
                        size_t max_size,
                        size_t num_requests);
 
  void GenerateRequest(random::RandomGenerator& prng, size_t max_size);
 
  void HandleRequests(const Vector<Request>& requests);
 
  void HandleRequest(const Request& request);
 
  void Reset();
 
 protected:
  struct Allocation {
    void* ptr;
    Layout layout;
  };
 
  constexpr TestHarnessGeneric(Vector<Allocation>& allocations)
      : allocations_(allocations) {}
 
 private:
  virtual Allocator* Init() = 0;
 
  void AddAllocation(void* ptr, Layout layout);
 
  Allocation RemoveAllocation(size_t index);
 
  Allocator* allocator_ = nullptr;
 
  Vector<Allocation>& allocations_;
 
  size_t num_requests_ = 0;
};
 
template <size_t kMaxConcurrentAllocations>
class TestHarness : public TestHarnessGeneric {
 public:
  constexpr TestHarness() : TestHarnessGeneric(allocations_) {}
 
 private:
  Vector<Allocation, kMaxConcurrentAllocations> allocations_;
};
 
}  // namespace pw::allocator::test