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Diffstat (limited to 'nuttx/sched/kmm_krealloc.c')
-rw-r--r-- | nuttx/sched/kmm_krealloc.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/nuttx/sched/kmm_krealloc.c b/nuttx/sched/kmm_krealloc.c new file mode 100644 index 000000000..3d3726566 --- /dev/null +++ b/nuttx/sched/kmm_krealloc.c @@ -0,0 +1,111 @@ +/************************************************************************ + * sched/kmm_krealloc.c + * + * Copyright (C) 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * 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 OWNER 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. + * + ************************************************************************/ + +/************************************************************************ + * Included Files + ************************************************************************/ + +#include <nuttx/config.h> +#include <nuttx/kmalloc.h> + +#ifdef CONFIG_NUTTX_KERNEL + +/* This logic is all tentatively and, hopefully, will grow in usability. + * For now, the kernel-mode build uses the memory manager that is + * provided in the user-space build. That is awkward but reasonable for + * the current level of support: At present, only memory protection is + * provided. Kernel-mode code may call into user-mode code, but not + * vice-versa. So hosting the memory manager in user-space allows the + * memory manager to be shared in both kernel- and user-mode spaces. + * + * In the longer run, if an MMU is support that can provide virtualized + * memory, then some SLAB memory manager will be required in kernel-space + * with some kind of brk() system call to obtain mapped heap space. + * + * In the current build model, the user-space module is built first. The + * file user_map.h is generated in the first pass and contains the + * addresses of the memory manager needed in this file: + */ + +#include <arch/board/user_map.h> + +/************************************************************************ + * Pre-processor definition + ************************************************************************/ + +/* This value is obtained from user_map.h */ + +#define KREALLOC(p,s) ((krealloc_t)CONFIG_USER_REALLOC)(p,s) + +/************************************************************************ + * Private Types + ************************************************************************/ + +typedef FAR void *(*krealloc_t)(FAR void*, size_t); + +/************************************************************************ + * Private Functions + ************************************************************************/ + +/************************************************************************ + * Public Functions + ************************************************************************/ + +/************************************************************************ + * Name: krealloc + * + * Description: + * This is a simple redirection to the user-space realloc() function. + * + * Parameters: + * oldmem - The old memory allocated + * size - Size (in bytes) of the new memory region to be re-allocated. + * + * Return Value: + * The address of the re-allocated memory (NULL on failure to re-allocate) + * + * Assumptions: + * 1. realloc() resides in user-space + * 2. The address of the user space realloc() is provided in user_map.h + * 3. The user-space realloc() is callable from kernel-space. + * + ************************************************************************/ + +FAR void *krealloc(FAR void *oldmem, size_t size) +{ + return KREALLOC(oldmem, size); +} + +#endif /* CONFIG_NUTTX_KERNEL */ |