block-pool.h

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/*
 * This file is part of the µOS++ project (https://micro-os-plus.github.io/).
 * Copyright (c) 2016-2025 Liviu Ionescu. All rights reserved.
 *
 * Permission to use, copy, modify, and/or distribute this software
 * for any purpose is hereby granted, under the terms of the MIT license.
 *
 * If a copy of the license was not distributed with this file, it can
 * be obtained from https://opensource.org/licenses/mit.
 */
 
#ifndef CMSIS_PLUS_MEMORY_BLOCK_POOL_H_
#define CMSIS_PLUS_MEMORY_BLOCK_POOL_H_
 
// ----------------------------------------------------------------------------
 
#if defined(__cplusplus)
 
// ----------------------------------------------------------------------------
 
#include <cmsis-plus/rtos/os.h>
 
// ----------------------------------------------------------------------------
 
#pragma GCC diagnostic push
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wc++98-compat"
#endif
 
// ----------------------------------------------------------------------------
 
namespace os
{
  namespace memory
  {
 
    // ========================================================================
 
    class block_pool : public rtos::memory::memory_resource
    {
    public:
      block_pool (std::size_t blocks, std::size_t block_size_bytes, void* addr,
                  std::size_t bytes);
 
      block_pool (const char* name, std::size_t blocks,
                  std::size_t block_size_bytes, void* addr, std::size_t bytes);
 
    protected:
      block_pool (const char* name);
 
    public:
      // The rule of five.
      block_pool (const block_pool&) = delete;
      block_pool (block_pool&&) = delete;
      block_pool&
      operator= (const block_pool&)
          = delete;
      block_pool&
      operator= (block_pool&&)
          = delete;
 
      virtual ~block_pool () override;
 
    protected:
      void
      internal_construct_ (std::size_t blocks, std::size_t block_size_bytes,
                           void* addr, std::size_t bytes) noexcept;
 
      void
      internal_reset_ (void) noexcept;
 
      virtual void*
      do_allocate (std::size_t bytes, std::size_t alignment) override;
 
      virtual void
      do_deallocate (void* addr, std::size_t bytes,
                     std::size_t alignment) noexcept override;
 
      virtual std::size_t
      do_max_size (void) const noexcept override;
 
      virtual void
      do_reset (void) noexcept override;
 
    protected:
      void* pool_addr_ = nullptr;
 
      void* volatile first_ = nullptr;
 
      std::size_t blocks_ = 0;
 
      std::size_t block_size_bytes_ = 0;
 
      volatile std::size_t count_ = 0;
 
    };
 
    // ========================================================================
 
    template <typename T, std::size_t N>
    class block_pool_typed_inclusive : public block_pool
    {
    public:
      using value_type = T;
 
      static_assert (
          sizeof (value_type) >= sizeof (void*),
          "Template type T must be large enough to store a pointer.");
 
      static const std::size_t blocks = N;
 
      block_pool_typed_inclusive (void);
 
      block_pool_typed_inclusive (const char* name);
 
    public:
      // The rule of five.
      block_pool_typed_inclusive (const block_pool_typed_inclusive&) = delete;
      block_pool_typed_inclusive (block_pool_typed_inclusive&&) = delete;
      block_pool_typed_inclusive&
      operator= (const block_pool_typed_inclusive&)
          = delete;
      block_pool_typed_inclusive&
      operator= (block_pool_typed_inclusive&&)
          = delete;
 
      virtual ~block_pool_typed_inclusive () override;
 
    protected:
      typename std::aligned_storage<sizeof (value_type),
                                    alignof (value_type)>::type arena_[blocks];
 
    };
 
    // ========================================================================
 
    template <typename T, typename A = os::rtos::memory::allocator<T>>
    class block_pool_typed_allocated : public block_pool
    {
    public:
      using value_type = T;
 
      static_assert (
          sizeof (value_type) >= sizeof (void*),
          "Template type T must be large enough to store a pointer.");
 
      using allocator_type = A;
 
      using allocator_traits = std::allocator_traits<A>;
 
      // It is recommended to have the same type, but at least the types
      // should have the same size.
      static_assert (
          sizeof (value_type)
              == sizeof (typename allocator_traits::value_type),
          "The allocator must be parametrised with a type of same size.");
 
      block_pool_typed_allocated (std::size_t blocks,
                                  const allocator_type& allocator
                                  = allocator_type ());
 
      block_pool_typed_allocated (const char* name, std::size_t blocks,
                                  const allocator_type& allocator
                                  = allocator_type ());
 
    public:
      // The rule of five.
      block_pool_typed_allocated (const block_pool_typed_allocated&) = delete;
      block_pool_typed_allocated (block_pool_typed_allocated&&) = delete;
      block_pool_typed_allocated&
      operator= (const block_pool_typed_allocated&)
          = delete;
      block_pool_typed_allocated&
      operator= (block_pool_typed_allocated&&)
          = delete;
 
      virtual ~block_pool_typed_allocated () override;
 
    protected:
      allocator_type* allocator_ = nullptr;
 
    };
 
    // -------------------------------------------------------------------------
  } /* namespace memory */
} /* namespace os */
 
// ===== Inline & template implementations ====================================
 
namespace os
{
  namespace memory
  {
 
    // ========================================================================
 
    inline block_pool::block_pool (const char* name)
        : rtos::memory::memory_resource{ name }
    {
    }
 
    inline block_pool::block_pool (std::size_t blocks,
                                   std::size_t block_size_bytes, void* addr,
                                   std::size_t bytes)
        : block_pool{ nullptr, blocks, block_size_bytes, addr, bytes }
    {
    }
 
    inline block_pool::block_pool (const char* name, std::size_t blocks,
                                   std::size_t block_size_bytes, void* addr,
                                   std::size_t bytes)
        : rtos::memory::memory_resource{ name }
    {
      trace::printf ("%s(%u,%u,%p,%u) @%p %s\n", __func__, blocks,
                     block_size_bytes, addr, bytes, this, this->name ());
 
      internal_construct_ (blocks, block_size_bytes, addr, bytes);
    }
 
    // ========================================================================
 
    template <typename T, std::size_t N>
    inline block_pool_typed_inclusive<T, N>::block_pool_typed_inclusive ()
        : block_pool_typed_inclusive (nullptr)
    {
    }
 
    template <typename T, std::size_t N>
    inline block_pool_typed_inclusive<T, N>::block_pool_typed_inclusive (
        const char* name)
        : block_pool{ name }
    {
      trace::printf ("%s() @%p %s\n", __func__, this, this->name ());
 
      internal_construct_ (blocks, sizeof (value_type), &arena_[0],
                           sizeof (arena_));
    }
 
    template <typename T, std::size_t N>
    block_pool_typed_inclusive<T, N>::~block_pool_typed_inclusive ()
    {
      trace::printf ("%s() @%p %s\n", __func__, this, this->name ());
    }
 
    // ========================================================================
 
    template <typename T, typename A>
    inline block_pool_typed_allocated<T, A>::block_pool_typed_allocated (
        std::size_t blocks, const allocator_type& allocator)
        : block_pool_typed_allocated (nullptr, blocks, allocator)
    {
    }
 
    template <typename T, typename A>
    block_pool_typed_allocated<T, A>::block_pool_typed_allocated (
        const char* name, std::size_t blocks, const allocator_type& allocator)
        : block_pool{ name }
    {
      trace::printf ("%s(%u,%p) @%p %s\n", __func__, blocks, &allocator, this,
                     this->name ());
 
      // Remember the allocator, it'll be used by the destructor.
      allocator_ = static_cast<allocator_type*> (
          &const_cast<allocator_type&> (allocator));
 
      void* addr = allocator_->allocate (blocks);
      if (addr == nullptr)
        {
          estd::__throw_bad_alloc ();
        }
 
      internal_construct_ (blocks, sizeof (value_type), addr,
                           blocks * sizeof (value_type));
    }
 
    template <typename T, typename A>
    block_pool_typed_allocated<T, A>::~block_pool_typed_allocated ()
    {
      trace::printf ("%s() @%p %s\n", __func__, this, this->name ());
 
      // Skip in case a derived class did the deallocation.
      if (allocator_ != nullptr)
        {
          allocator_->deallocate (
              static_cast<typename allocator_traits::pointer> (pool_addr_),
              blocks_);
 
          // Prevent another deallocation.
          allocator_ = nullptr;
        }
    }
 
    // ------------------------------------------------------------------------
 
  } /* namespace memory */
} /* namespace os */
 
#pragma GCC diagnostic pop
 
// ----------------------------------------------------------------------------
 
#endif /* __cplusplus */
 
// ----------------------------------------------------------------------------
 
#endif /* CMSIS_PLUS_MEMORY_BLOCK_POOL_H_ */