cpukit/libdl/rtl-bit-alloc.h

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup rtems_rtl
0007  *
0008  * @brief RTEMS Run-Time Linker Bit Allocator Header
0009  */
0010
0011 /*
0012  *  COPYRIGHT (c) 2019 Chris Johns <chrisj@rtems.org>
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #if !defined (_RTEMS_RTL_BIT_ALLOC_H_)
0037 #define _RTEMS_RTL_BIT_ALLOC_H_
0038
0039 #include <rtems/rtl/rtl-fwd.h>
0040 #include <rtems/rtl/rtl-obj-fwd.h>
0041
0042 #ifdef __cplusplus
0043 extern "C" {
0044 #endif /* __cplusplus */
0045
0046 /**
0047  * Bit Allocator data
0048  */
0049 typedef struct rtems_rtl_bit_alloc
0050 {
0051   uint8_t*  base;       /**< The memory being allocated. */
0052   size_t    size;       /**< The number of bytes of memory being managed. */
0053   uint32_t* bits;       /**< The bit map indicating which blocks are allocated. */
0054   size_t    block_size; /**< The size of a block, the minimum allocation unit. */
0055   size_t    blocks;     /**< The number of blocks in the memory. */
0056 } rtems_rtl_bit_alloc;
0057
0058 /**
0059  * Open a bit allocator. The allocator allocates block_size pieces of the memory
0060  * being managed.
0061  *
0062  * @param base The memory to managem NULL to allocate a piece of memory.
0063  * @param size The size of the memory being managed in bytes.
0064  * @param block_size The minimum allocation unit in bytes.
0065  * @param used The amount of memory already in use in bytes.
0066  * @retval rtems_rtl_bit_alloc The bit allocator structure.
0067  */
0068 rtems_rtl_bit_alloc* rtems_rtl_bit_alloc_open (void*  base,
0069                                                size_t size,
0070                                                size_t block_size,
0071                                                size_t used);
0072
0073 /**
0074  * Close the bit allocator.
0075  *
0076  * @param balloc The allocator to close.
0077  */
0078
0079 void rtems_rtl_bit_alloc_close (rtems_rtl_bit_alloc* balloc);
0080
0081 /**
0082  * Allocate a piece of memory being managed. The size is in bytes are is rounded
0083  * up the next block size.
0084  *
0085  * @param balloc The allocator.
0086  * @param size Number of bytes to allocate.
0087  * @return void* The memory if the allocation is successful else NULL if there
0088  *               is no more memory.
0089  */
0090 void* rtems_rtl_bit_alloc_balloc (rtems_rtl_bit_alloc* balloc, size_t size);
0091
0092 /**
0093  * Free an allocated memory block. The size is required because the allocator does not
0094  * contain any state information.
0095  */
0096 void rtems_rtl_bit_alloc_bfree (rtems_rtl_bit_alloc* balloc, void* addr, size_t size);
0097
0098 #ifdef __cplusplus
0099 }
0100 #endif /* __cplusplus */
0101
0102 #endif