/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file allocator.h
* Interface for custom allocators.
*/
#ifndef UCX_ALLOCATOR_H
#define UCX_ALLOCATOR_H
#include "common.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* The class definition for an allocator.
*/
typedef struct {
/**
* The allocator's malloc() implementation.
*/
void *(*malloc)(
void *data,
size_t n
);
/**
* The allocator's realloc() implementation.
*/
void *(*realloc)(
void *data,
void *mem,
size_t n
)
__attribute__((__warn_unused_result__));
/**
* The allocator's calloc() implementation.
*/
void *(*calloc)(
void *data,
size_t nelem,
size_t n
);
/**
* The allocator's free() implementation.
*/
void (*free)(
void *data,
void *mem
)
__attribute__((__nonnull__));
} cx_allocator_class;
/**
* Structure holding the data for an allocator.
*/
struct cx_allocator_s {
/**
* A pointer to the instance of the allocator class.
*/
cx_allocator_class *cl;
/**
* A pointer to the data this allocator uses.
*/
void *data;
};
/**
* High-Level type alias for the allocator type.
*/
typedef struct cx_allocator_s CxAllocator;
/**
* A default allocator using standard library malloc() etc.
*/
extern CxAllocator *cxDefaultAllocator;
/**
* Function pointer type for destructor functions.
*
* A destructor function deallocates possible contents and MAY free the memory
* pointed to by \p memory. Read the documentation of the respective function
* pointer to learn if a destructor SHALL, MAY, or MUST NOT free the memory in that
* particular implementation.
*
* @param memory a pointer to the object to destruct
*/
typedef void (*cx_destructor_func)(void *memory) __attribute__((__nonnull__));
/**
* Function pointer type for destructor functions.
*
* A destructor function deallocates possible contents and MAY free the memory
* pointed to by \p memory. Read the documentation of the respective function
* pointer to learn if a destructor SHALL, MAY, or MUST NOT free the memory in that
* particular implementation.
*
* @param data an optional pointer to custom data
* @param memory a pointer to the object to destruct
*/
typedef void (*cx_destructor_func2)(
void *data,
void *memory
) __attribute__((__nonnull__(2)));
/**
* Re-allocate a previously allocated block and changes the pointer in-place, if necessary.
*
* \par Error handling
* \c errno will be set by realloc() on failure.
*
* @param mem pointer to the pointer to allocated block
* @param n the new size in bytes
* @return zero on success, non-zero on failure
*/
int cx_reallocate(
void **mem,
size_t n
)
__attribute__((__nonnull__));
/**
* Allocate \p n bytes of memory.
*
* @param allocator the allocator
* @param n the number of bytes
* @return a pointer to the allocated memory
*/
void *cxMalloc(
CxAllocator const *allocator,
size_t n
)
__attribute__((__malloc__))
__attribute__((__alloc_size__(2)));
/**
* Re-allocate the previously allocated block in \p mem, making the new block \p n bytes long.
* This function may return the same pointer that was passed to it, if moving the memory
* was not necessary.
*
* \note Re-allocating a block allocated by a different allocator is undefined.
*
* @param allocator the allocator
* @param mem pointer to the previously allocated block
* @param n the new size in bytes
* @return a pointer to the re-allocated memory
*/
void *cxRealloc(
CxAllocator const *allocator,
void *mem,
size_t n
)
__attribute__((__warn_unused_result__))
__attribute__((__alloc_size__(3)));
/**
* Re-allocate a previously allocated block and changes the pointer in-place, if necessary.
* This function acts like cxRealloc() using the pointer pointed to by \p mem.
*
* \note Re-allocating a block allocated by a different allocator is undefined.
*
* \par Error handling
* \c errno will be set, if the underlying realloc function does so.
*
* @param allocator the allocator
* @param mem pointer to the pointer to allocated block
* @param n the new size in bytes
* @return zero on success, non-zero on failure
*/
int cxReallocate(
CxAllocator const *allocator,
void **mem,
size_t n
)
__attribute__((__nonnull__));
/**
* Allocate \p nelem elements of \p n bytes each, all initialized to zero.
*
* @param allocator the allocator
* @param nelem the number of elements
* @param n the size of each element in bytes
* @return a pointer to the allocated memory
*/
void *cxCalloc(
CxAllocator const *allocator,
size_t nelem,
size_t n
)
__attribute__((__malloc__))
__attribute__((__alloc_size__(2, 3)));
/**
* Free a block allocated by this allocator.
*
* \note Freeing a block of a different allocator is undefined.
*
* @param allocator the allocator
* @param mem a pointer to the block to free
*/
void cxFree(
CxAllocator const *allocator,
void *mem
)
__attribute__((__nonnull__));
#ifdef __cplusplus
} // extern "C"
#endif
#endif // UCX_ALLOCATOR_H