/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 2016 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.
*/
/**
* Allocator for custom memory management.
*
* A UCX allocator consists of a pointer to the memory area / pool and four
* function pointers to memory management functions operating on this memory
* area / pool. These functions shall behave equivalent to the standard libc
* functions <code>malloc(), calloc(), realloc()</code> and <code>free()</code>.
*
* The signature of the memory management functions is based on the signature
* of the respective libc function but each of them takes the pointer to the
* memory area / pool as first argument.
*
* As the pointer to the memory area / pool can be arbitrarily chosen, any data
* can be provided to the memory management functions. A UcxMempool is just
* one example.
*
* @see mempool.h
* @see UcxMap
*
* @file allocator.h
* @author Mike Becker
* @author Olaf Wintermann
*/
#ifndef UCX_ALLOCATOR_H
#define UCX_ALLOCATOR_H
#include "ucx.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* A function pointer to the allocators <code>malloc()</code> function.
* @see UcxAllocator
*/
typedef void*(*ucx_allocator_malloc)(void *pool, size_t n);
/**
* A function pointer to the allocators <code>calloc()</code> function.
* @see UcxAllocator
*/
typedef void*(*ucx_allocator_calloc)(void *pool, size_t n, size_t size);
/**
* A function pointer to the allocators <code>realloc()</code> function.
* @see UcxAllocator
*/
typedef void*(*ucx_allocator_realloc)(void *pool, void *data, size_t n);
/**
* A function pointer to the allocators <code>free()</code> function.
* @see UcxAllocator
*/
typedef void(*ucx_allocator_free)(void *pool, void *data);
/**
* UCX allocator data structure containing memory management functions.
*/
typedef struct {
/** Pointer to an area of memory or a complex memory pool.
* This pointer will be passed to any memory management function as first
* argument.
*/
void *pool;
/**
* The <code>malloc()</code> function for this allocator.
*/
ucx_allocator_malloc malloc;
/**
* The <code>calloc()</code> function for this allocator.
*/
ucx_allocator_calloc calloc;
/**
* The <code>realloc()</code> function for this allocator.
*/
ucx_allocator_realloc realloc;
/**
* The <code>free()</code> function for this allocator.
*/
ucx_allocator_free free;
} UcxAllocator;
/**
* Returns a pointer to the default allocator.
*
* The default allocator contains wrappers to the standard libc memory
* management functions. Use this function to get a pointer to a globally
* available allocator. You may also define an own UcxAllocator by assigning
* #UCX_ALLOCATOR_DEFAULT to a variable and pass the address of this variable
* to any function that takes a UcxAllocator as argument. Note that using
* this function is the recommended way of passing a default allocator, thus
* it never runs out of scope.
*
* @return a pointer to the default allocator
*
* @see UCX_ALLOCATOR_DEFAULT
*/
UcxAllocator *ucx_default_allocator();
/**
* A wrapper for the standard libc <code>malloc()</code> function.
* @param ignore ignored (may be used by allocators for pooled memory)
* @param n argument passed to <code>malloc()</code>
* @return return value of <code>malloc()</code>
*/
void *ucx_default_malloc(void *ignore, size_t n);
/**
* A wrapper for the standard libc <code>calloc()</code> function.
* @param ignore ignored (may be used by allocators for pooled memory)
* @param n argument passed to <code>calloc()</code>
* @param size argument passed to <code>calloc()</code>
* @return return value of <code>calloc()</code>
*/
void *ucx_default_calloc(void *ignore, size_t n, size_t size);
/**
* A wrapper for the standard libc <code>realloc()</code> function.
* @param ignore ignored (may be used by allocators for pooled memory)
* @param data argumend passed to <code>realloc()</code>
* @param n argument passed to <code>realloc()</code>
* @return return value of <code>realloc()</code>
*/
void *ucx_default_realloc(void *ignore, void *data, size_t n);
/**
* A wrapper for the standard libc <code>free()</code> function.
* @param ignore ignored (may be used by allocators for pooled memory)
* @param data argument passed to <code>free()</code>
*/
void ucx_default_free(void *ignore, void *data);
/**
* Shorthand for calling an allocators malloc function.
* @param allocator the allocator to use
* @param n size of space to allocate
* @return a pointer to the allocated memory area
*/
#define almalloc(allocator, n) ((allocator)->malloc((allocator)->pool, n))
/**
* Shorthand for calling an allocators calloc function.
* @param allocator the allocator to use
* @param n the count of elements the space should be allocated for
* @param size the size of each element
* @return a pointer to the allocated memory area
*/
#define alcalloc(allocator, n, size) \
((allocator)->calloc((allocator)->pool, n, size))
/**
* Shorthand for calling an allocators realloc function.
* @param allocator the allocator to use
* @param ptr the pointer to the memory area that shall be reallocated
* @param n the new size of the allocated memory area
* @return a pointer to the reallocated memory area
*/
#define alrealloc(allocator, ptr, n) \
((allocator)->realloc((allocator)->pool, ptr, n))
/**
* Shorthand for calling an allocators free function.
* @param allocator the allocator to use
* @param ptr the pointer to the memory area that shall be freed
*/
#define alfree(allocator, ptr) ((allocator)->free((allocator)->pool, ptr))
/**
* Convenient macro for a default allocator <code>struct</code> definition.
*/
#define UCX_ALLOCATOR_DEFAULT {NULL, \
ucx_default_malloc, ucx_default_calloc, ucx_default_realloc, \
ucx_default_free }
#ifdef __cplusplus
}
#endif
#endif /* UCX_ALLOCATOR_H */