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85 lines
1.9 KiB
Markdown
85 lines
1.9 KiB
Markdown
---
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title: "imemory_block_allocator"
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---
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{{< callout >}}
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Header: `imemory_block_allocator.h`
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{{< /callout >}}
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The base of all memory block allocators.
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Inherits from traits class `etl::successor<imemory_block_allocator>`.
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Defines the functionality and interface for derived memory block allocators.
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The class defines a public non-virtual interface and protected virtual overrides.
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A derived class must define these overrides.
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## Types
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```cpp
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successor_type
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```
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## Non-virtual public interface
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```cpp
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void* allocate(size_t required_size, size_t required_alignment)
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```
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**Description**
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Attempts to allocate a memory block of the required size (in char) and alignment and return a pointer to it.
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If the allocator is unable to do this and it has a successor, then the request will be passed on to it, otherwise `ETL_NULLPTR` will be returned.
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---
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```cpp
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bool release(const void* const p)
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```
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**Description**
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Attempts to release a memory block and returns `true` if successful.
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If the allocator is unable to do this and it has a successor, then the request will be passed on to it, otherwise `false` will be returned.
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---
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## Virtual protected interface
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```cpp
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virtual void* allocate_block(size_t required_size, size_t required_alignment) = 0;
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```
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**Description**
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The derived class must implement this function.
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It will attempt to allocate a block of the required size. If it is unable to, it must return `ETL_NULLPTR`.
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---
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```cpp
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virtual bool release_block(const void* const) = 0;
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```
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**Description**
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The derived class must implement this function.
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It will attempt to release a block. If it is unable to, it must return `false`.
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---
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```cpp
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void set_successor(successor_type& s)
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```
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**Description**
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Set the successor.
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---
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```cpp
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successor_type& get_successor() const
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```
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**Description**
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Get the successor.
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---
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```cpp
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bool has_successor() const
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```
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**Description**
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Returns `true` if a successor has been set.
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