120 lines
3.9 KiB
C
120 lines
3.9 KiB
C
/* threadless.io
|
|
* Copyright (c) 2016 Justin R. Cutler
|
|
* Licensed under the MIT License. See LICENSE file in the project root for
|
|
* full license information.
|
|
*/
|
|
/** @file
|
|
* allocation interface definition
|
|
* @author Justin R. Cutler <justin.r.cutler@gmail.com>
|
|
*/
|
|
#ifndef THREADLESS_ALLOCATION_H
|
|
#define THREADLESS_ALLOCATION_H
|
|
|
|
/* size_t, NULL */
|
|
#include <stddef.h>
|
|
|
|
/** Memory allocator instance */
|
|
typedef struct allocator allocator_t;
|
|
|
|
/** Memory allocation handle */
|
|
typedef struct {
|
|
/** allocator used to manage this memory */
|
|
allocator_t *allocator;
|
|
/** pointer to allocated memory */
|
|
void *memory;
|
|
/** current size of allocated memory */
|
|
size_t size;
|
|
} allocation_t;
|
|
|
|
/** Memory allocator function
|
|
* @param[in,out] allocation memory allocation handle
|
|
* @param size minimum new size of memory (or 0 to free)
|
|
* @retval 0 success
|
|
* @retval -1 error
|
|
* @pre @p allocation must be initialized
|
|
* @pre If @p allocation->memory is @c NULL and @p allocation->size is
|
|
* non-zero, function shall allocate new memory
|
|
* @pre If @p size is 0, function shall free allocated memory
|
|
* @post Upon success, @p allocation has been updated to reflect changes
|
|
* @post Upon failure, @p allocation has not been changed
|
|
*/
|
|
typedef int (allocator_function_t)(allocation_t *allocation, size_t size);
|
|
|
|
/** Memory allocator destructor function
|
|
* @param[in,out] allocator allocator instance
|
|
* @post @p allocator may no longer be used
|
|
*/
|
|
typedef void (allocator_destroy_function_t)(allocator_t *allocator);
|
|
|
|
/** Memory allocator instance structure */
|
|
struct allocator {
|
|
/** Memory (re)allocator function */
|
|
allocator_function_t *const allocate;
|
|
/** Memory allocator instance destructor */
|
|
allocator_destroy_function_t *const destroy;
|
|
};
|
|
|
|
#ifdef __cplusplus
|
|
extern "C" {
|
|
#endif /* __cplusplus */
|
|
|
|
/** Initialize an allocation handle
|
|
* @param[out] allocation allocation
|
|
* @param allocator allocator instance
|
|
* @pre @p allocation must be initialized
|
|
* @post @p allocation->allocator has been set to @p allocator,
|
|
* @p allocation->memory has been set to @c NULL, and @p allocation->size
|
|
* has been set to 0
|
|
*/
|
|
static inline void allocation_init(allocation_t *allocation,
|
|
allocator_t *allocator)
|
|
{
|
|
allocation->allocator = allocator;
|
|
allocation->memory = NULL;
|
|
allocation->size = 0;
|
|
}
|
|
|
|
/** @c realloc_array() helper function
|
|
* @param[in,out] allocation memory allocation handle
|
|
* @param nmemb number of elements to allocate (or 0 to free)
|
|
* @param size size of each element to allocate (or 0 to free)
|
|
* @retval 0 success
|
|
* @retval -1 error
|
|
* @pre @p allocation must point to an initialized, valid allocation
|
|
* @pre If @p allocation->memory is @c NULL, function shall allocate new
|
|
* memory
|
|
* @pre If @p nmemb or @p size is 0, function shall free allocated memory
|
|
* @post Upon success, @p allocation->memory and @p allocation->size have been
|
|
* updated to reflect changes
|
|
* @post Upon failure, @p allocation has not been changed
|
|
* @note Upon detection of integer overflow, this function shall return
|
|
* @c NULL (like @c calloc(3) and FreeBSD's @c realloc_array(3))
|
|
*/
|
|
int allocation_realloc_array(allocation_t *allocation, size_t nmemb,
|
|
size_t size);
|
|
|
|
/** @c free() helper function
|
|
* @param[in,out] allocation memory allocation handle
|
|
* @pre @p allocation must point to an initialized, valid allocation
|
|
* @post @p allocation->memory is set to @c NULL and @p allocation->size is set
|
|
* to 0
|
|
*/
|
|
static inline void allocation_free(allocation_t *allocation)
|
|
{
|
|
(void) allocation_realloc_array(allocation, 0, 0);
|
|
}
|
|
|
|
/** Memory allocator destructor helper function
|
|
* @copydetails allocator_destroy_function_t
|
|
*/
|
|
static inline void allocator_destroy(allocator_t *allocator)
|
|
{
|
|
allocator->destroy(allocator);
|
|
}
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif /* __cplusplus */
|
|
|
|
#endif /* THREADLESS_ALLOCATOR_H */
|