tinySA/os/common/oslib/include/chheap.h

179 lines
6.2 KiB
C

/*
ChibiOS - Copyright (C) 2006..2016 Giovanni Di Sirio.
This file is part of ChibiOS.
ChibiOS 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 3 of the License, or
(at your option) any later version.
ChibiOS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file chheap.h
* @brief Heaps macros and structures.
*
* @addtogroup heaps
* @{
*/
#ifndef CHHEAP_H
#define CHHEAP_H
#if (CH_CFG_USE_HEAP == TRUE) || defined(__DOXYGEN__)
/*===========================================================================*/
/* Module constants. */
/*===========================================================================*/
/**
* @brief Minimum alignment used for heap.
* @note Cannot use the sizeof operator in this macro.
*/
#if (SIZEOF_PTR == 4) || defined(__DOXYGEN__)
#define CH_HEAP_ALIGNMENT 8
#elif (SIZEOF_PTR == 2)
#define CH_HEAP_ALIGNMENT 4
#else
#error "unsupported pointer size"
#endif
/*===========================================================================*/
/* Module pre-compile time settings. */
/*===========================================================================*/
/*===========================================================================*/
/* Derived constants and error checks. */
/*===========================================================================*/
#if CH_CFG_USE_MEMCORE == FALSE
#error "CH_CFG_USE_HEAP requires CH_CFG_USE_MEMCORE"
#endif
#if (CH_CFG_USE_MUTEXES == FALSE) && (CH_CFG_USE_SEMAPHORES == FALSE)
#error "CH_CFG_USE_HEAP requires CH_CFG_USE_MUTEXES and/or CH_CFG_USE_SEMAPHORES"
#endif
/*===========================================================================*/
/* Module data structures and types. */
/*===========================================================================*/
/**
* @brief Type of a memory heap.
*/
typedef struct memory_heap memory_heap_t;
/**
* @brief Type of a memory heap header.
*/
typedef union heap_header heap_header_t;
/**
* @brief Memory heap block header.
*/
union heap_header {
stkalign_t align;
struct {
heap_header_t *next; /**< @brief Next block in free list. */
size_t pages; /**< @brief Size of the area in pages. */
} free;
struct {
memory_heap_t *heap; /**< @brief Block owner heap. */
size_t size; /**< @brief Size of the area in bytes. */
} used;
};
/**
* @brief Structure describing a memory heap.
*/
struct memory_heap {
memgetfunc_t provider; /**< @brief Memory blocks provider for
this heap. */
heap_header_t header; /**< @brief Free blocks list header. */
#if CH_CFG_USE_MUTEXES == TRUE
mutex_t mtx; /**< @brief Heap access mutex. */
#else
semaphore_t sem; /**< @brief Heap access semaphore. */
#endif
};
/*===========================================================================*/
/* Module macros. */
/*===========================================================================*/
/**
* @brief Allocation of an aligned static heap buffer.
*/
#define CH_HEAP_AREA(name, size) \
ALIGNED_VAR(CH_HEAP_ALIGNMENT) \
uint8_t name[MEM_ALIGN_NEXT((size), CH_HEAP_ALIGNMENT)]
/*===========================================================================*/
/* External declarations. */
/*===========================================================================*/
#ifdef __cplusplus
extern "C" {
#endif
void _heap_init(void);
void chHeapObjectInit(memory_heap_t *heapp, void *buf, size_t size);
void *chHeapAllocAligned(memory_heap_t *heapp, size_t size, unsigned align);
void chHeapFree(void *p);
size_t chHeapStatus(memory_heap_t *heapp, size_t *totalp, size_t *largestp);
#ifdef __cplusplus
}
#endif
/*===========================================================================*/
/* Module inline functions. */
/*===========================================================================*/
/**
* @brief Allocates a block of memory from the heap by using the first-fit
* algorithm.
* @details The allocated block is guaranteed to be properly aligned for a
* pointer data type.
*
* @param[in] heapp pointer to a heap descriptor or @p NULL in order to
* access the default heap.
* @param[in] size the size of the block to be allocated. Note that the
* allocated block may be a bit bigger than the requested
* size for alignment and fragmentation reasons.
* @return A pointer to the allocated block.
* @retval NULL if the block cannot be allocated.
*
* @api
*/
static inline void *chHeapAlloc(memory_heap_t *heapp, size_t size) {
return chHeapAllocAligned(heapp, size, CH_HEAP_ALIGNMENT);
}
/**
* @brief Returns the size of an allocated block.
* @note The returned value is the requested size, the real size is the
* same value aligned to the next @p CH_HEAP_ALIGNMENT multiple.
*
* @param[in] p pointer to the memory block
*
* @api
*/
static inline size_t chHeapGetSize(const void *p) {
return ((heap_header_t *)p)->used.size;
}
#endif /* CH_CFG_USE_HEAP == TRUE */
#endif /* CHHEAP_H */
/** @} */