rockbox/firmware/include/buflib_mempool.h
Aidan MacDonald f2f198663e buflib: Move the API back into buflib.h
To minimize code duplication between buflib backends move the
public part of the API to buflib.h. Also rewrote documentation
for the whole API.

Change-Id: I4d7ed6d02084d7130cb41511e63c25ec45b51703
2023-01-15 10:04:13 +00:00

64 lines
2.4 KiB
C

/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* This is a memory allocator designed to provide reasonable management of free
* space and fast access to allocated data. More than one allocator can be used
* at a time by initializing multiple contexts.
*
* Copyright (C) 2009 Andrew Mahone
* Copyright (C) 2011 Thomas Martitz
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#ifndef _BUFLIB_MEMPOOL_H_
#define _BUFLIB_MEMPOOL_H_
#ifndef _BUFLIB_H_
# error "include buflib.h instead"
#endif
union buflib_data
{
intptr_t val; /* length of the block in n*sizeof(union buflib_data).
Includes buflib metadata overhead. A negative value
indicates block is unallocated */
volatile unsigned pincount; /* number of pins */
struct buflib_callbacks* ops; /* callback functions for move and shrink. Can be NULL */
char* alloc; /* start of allocated memory area */
union buflib_data *handle; /* pointer to entry in the handle table.
Used during compaction for fast lookup */
};
struct buflib_context
{
union buflib_data *handle_table;
union buflib_data *first_free_handle;
union buflib_data *last_handle;
union buflib_data *buf_start;
union buflib_data *alloc_end;
bool compact;
};
#define BUFLIB_ALLOC_OVERHEAD (4 * sizeof(union buflib_data))
#ifndef BUFLIB_DEBUG_GET_DATA
static inline void *buflib_get_data(struct buflib_context *ctx, int handle)
{
return (void *)ctx->handle_table[-handle].alloc;
}
#endif
#endif /* _BUFLIB_MEMPOOL_H_ */