Nils O. Selåsdal
67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
#ifndef UC_SPOOL_H_
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#define UC_SPOOL_H_
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#include <stddef.h>
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#include <stdint.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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typedef union UCPoolBlock UCPoolBlock;
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union UCPoolBlock {
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UCPoolBlock *next; // next free block (when not allocated)
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unsigned char data[]; // data when allocated
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};
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/** @file
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* Static pool allocator.
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*
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* An UCPool allocates fixed size memory chunks from a provided buffer,
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* and memory allocations can be free'd in any order.
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*
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* The backing array should be suitable aligned to the types
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* that will be allocated from it. Use .e.g
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* @code
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* _Alignas(16) char mem[1024];
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* @endcode
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* as the backing buffer.
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*
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*/
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typedef struct UCPool UCPool;
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struct UCPool {
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UCPoolBlock *free_list; // free list
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size_t block_size; // aligned size of each block
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size_t capacity; // number of blocks
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size_t align; // alignment
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UCPoolBlock *start; // start of user buffer
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UCPoolBlock *end; // one past end of user buffer
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};
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/** Initialize the pool.
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*
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* Block size will be rounded up by alignment, or to size of a pointer
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*
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* @param buffer backing buffer for the pool
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* @param buffer_size size of @buffer
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* @param block_size size of each allocation.
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* @param alignment alignment of each block (must be power of 2)
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*/
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void uc_pool_init(UCPool *pool,
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void *buffer,
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size_t buffer_size,
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size_t block_size,
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size_t alignment);
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// Allocate a block from the pool. Returns NULL if no more space
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[[gnu::assume_aligned(_Alignof(UCPoolBlock))]]
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void *uc_pool_alloc(UCPool *pool);
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// Free @p . Returns memory to the pool
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void uc_pool_free(UCPool *pool, void *p);
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void uc_pool_reset(UCPool *pool);
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#ifdef __cplusplus
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}
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#endif
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#endif
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