/**
* @file
*
* @ingroup RTEMSScoreHeap
*
* @brief Heap Handler Implementation
*/
/*
* COPYRIGHT (c) 1989-2008.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifndef _RTEMS_SCORE_HEAPIMPL_H
#define _RTEMS_SCORE_HEAPIMPL_H
#include <rtems/score/heap.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @addtogroup RTEMSScoreHeap
*/
/**@{**/
/**
* @brief See also @ref Heap_Block.size_and_flag.
*/
#define HEAP_PREV_BLOCK_USED ((uintptr_t) 1)
/**
* @brief Size of the part at the block begin which may be used for allocation
* in charge of the previous block.
*/
#define HEAP_ALLOC_BONUS sizeof(uintptr_t)
/**
* @brief See _Heap_Resize_block().
*/
typedef enum {
HEAP_RESIZE_SUCCESSFUL,
HEAP_RESIZE_UNSATISFIED,
HEAP_RESIZE_FATAL_ERROR
} Heap_Resize_status;
/**
* @brief Gets the first and last block for the heap area with begin
* @a heap_area_begin and size @a heap_area_size.
*
* A page size of @a page_size and minimal block size of @a min_block_size will
* be used for calculation.
*
* Nothing will be written to this area.
*
* In case of success the pointers to the first and last block will be returned
* via @a first_block_ptr and @a last_block_ptr.
*
* Returns @c true if the area is big enough, and @c false otherwise.
*/
bool _Heap_Get_first_and_last_block(
uintptr_t heap_area_begin,
uintptr_t heap_area_size,
uintptr_t page_size,
uintptr_t min_block_size,
Heap_Block **first_block_ptr,
Heap_Block **last_block_ptr
);
/**
* @brief Initializes the heap control block @a heap to manage the area
* starting at @a area_begin of size @a area_size bytes.
*
* Blocks of memory are allocated from the heap in multiples of @a page_size
* byte units. If the @a page_size is equal to zero or is not multiple of
* @c CPU_ALIGNMENT, it is aligned up to the nearest @c CPU_ALIGNMENT boundary.
*
* Returns the maximum memory available, or zero in case of failure.
*
* @see Heap_Initialization_or_extend_handler.
*/
uintptr_t _Heap_Initialize(
Heap_Control *heap,
void *area_begin,
uintptr_t area_size,
uintptr_t page_size
);
/**
* @brief Allocates a memory area of size @a size bytes from the heap @a heap.
*
* If the alignment parameter @a alignment is not equal to zero, the allocated
* memory area will begin at an address aligned by this value.
*
* If the boundary parameter @a boundary is not equal to zero, the allocated
* memory area will fulfill a boundary constraint. The boundary value
* specifies the set of addresses which are aligned by the boundary value. The
* interior of the allocated memory area will not contain an element of this
* set. The begin or end address of the area may be a member of the set.
*
* A size value of zero will return a unique address which may be freed with
* _Heap_Free().
*
* Returns a pointer to the begin of the allocated memory area, or @c NULL if
* no memory is available or the parameters are inconsistent.
*/
void *_Heap_Allocate_aligned_with_boundary(
Heap_Control *heap,
uintptr_t size,
uintptr_t alignment,
uintptr_t boundary
);
/**
* @brief See _Heap_Allocate_aligned_with_boundary() with boundary equals zero.
*/
RTEMS_INLINE_ROUTINE void *_Heap_Allocate_aligned(
Heap_Control *heap,
uintptr_t size,
uintptr_t alignment
)
{
return _Heap_Allocate_aligned_with_boundary( heap, size, alignment, 0 );
}
/**
* @brief See _Heap_Allocate_aligned_with_boundary() with alignment and
* boundary equals zero.
*/
RTEMS_INLINE_ROUTINE void *_Heap_Allocate( Heap_Control *heap, uintptr_t size )
{
return _Heap_Allocate_aligned_with_boundary( heap, size, 0, 0 );
}
/**
* @brief Frees the allocated memory area starting at @a addr in the heap
* @a heap.
*
* Inappropriate values for @a addr may corrupt the heap.
*
* Returns @c true in case of success, and @c false otherwise.
*/
bool _Heap_Free( Heap_Control *heap, void *addr );
/**
* @brief Walks the heap @a heap to verify its integrity.
*
* If @a dump is @c true, then diagnostic messages will be printed to standard
* output. In this case @a source is used to mark the output lines.
*
* Returns @c true if no errors occurred, and @c false if the heap is corrupt.
*/
bool _Heap_Walk(
Heap_Control *heap,
int source,
bool dump
);
/**
* @brief Heap block visitor.
*
* @see _Heap_Iterate().
*
* @retval true Stop the iteration.
* @retval false Continue the iteration.
*/
typedef bool (*Heap_Block_visitor)(
const Heap_Block *block,
uintptr_t block_size,
bool block_is_used,
void *visitor_arg
);
/**
* @brief Iterates over all blocks of the heap.
*
* For each block the @a visitor with the argument @a visitor_arg will be
* called.
*/
void _Heap_Iterate(
Heap_Control *heap,
Heap_Block_visitor visitor,
void *visitor_arg
);
/**
* @brief Greedy allocate that empties the heap.
*
* Afterwards the heap has at most @a block_count allocatable blocks of sizes
* specified by @a block_sizes. The @a block_sizes must point to an array with
* @a block_count members. All other blocks are used.
*
* @see _Heap_Greedy_free().
*/
Heap_Block *_Heap_Greedy_allocate(
Heap_Control *heap,
const uintptr_t *block_sizes,
size_t block_count
);
/**
* @brief Greedy allocate all blocks except the largest free block.
*
* Afterwards the heap has at most one allocatable block. This block is the
* largest free block if it exists. The allocatable size of this block is
* stored in @a allocatable_size. All other blocks are used.
*
* @see _Heap_Greedy_free().
*/
Heap_Block *_Heap_Greedy_allocate_all_except_largest(
Heap_Control *heap,
uintptr_t *allocatable_size
);
/**
* @brief Frees blocks of a greedy allocation.
*
* The @a blocks must be the return value of _Heap_Greedy_allocate().
*/
void _Heap_Greedy_free(
Heap_Control *heap,
Heap_Block *blocks
);
/**
* @brief Returns information about used and free blocks for the heap @a heap
* in @a info.
*/
void _Heap_Get_information(
Heap_Control *heap,
Heap_Information_block *info
);
/**
* @brief Returns information about free blocks for the heap @a heap in
* @a info.
*/
void _Heap_Get_free_information(
Heap_Control *heap,
Heap_Information *info
);
/**
* @brief Returns the size of the allocatable memory area starting at @a addr
* in @a size.
*
* The size value may be greater than the initially requested size in
* _Heap_Allocate_aligned_with_boundary().
*
* Inappropriate values for @a addr will not corrupt the heap, but may yield
* invalid size values.
*
* Returns @a true if successful, and @c false otherwise.
*/
bool _Heap_Size_of_alloc_area(
Heap_Control *heap,
void *addr,
uintptr_t *size
);
/**
* @brief Resizes the block of the allocated memory area starting at @a addr.
*
* The new memory area will have a size of at least @a size bytes. A resize
* may be impossible and depends on the current heap usage.
*
* The size available for allocation in the current block before the resize
* will be returned in @a old_size. The size available for allocation in
* the resized block will be returned in @a new_size. If the resize was not
* successful, then a value of zero will be returned in @a new_size.
*
* Inappropriate values for @a addr may corrupt the heap.
*/
Heap_Resize_status _Heap_Resize_block(
Heap_Control *heap,
void *addr,
uintptr_t size,
uintptr_t *old_size,
uintptr_t *new_size
);
/**
* @brief Allocates the memory area starting at @a alloc_begin of size
* @a alloc_size bytes in the block @a block.
*
* The block may be split up into multiple blocks. The previous and next block
* may be used or free. Free block parts which form a vaild new block will be
* inserted into the free list or merged with an adjacent free block. If the
* block is used, they will be inserted after the free list head. If the block
* is free, they will be inserted after the previous block in the free list.
*
* Inappropriate values for @a alloc_begin or @a alloc_size may corrupt the
* heap.
*
* Returns the block containing the allocated memory area.
*/
Heap_Block *_Heap_Block_allocate(
Heap_Control *heap,
Heap_Block *block,
uintptr_t alloc_begin,
uintptr_t alloc_size
);
#ifndef HEAP_PROTECTION
#define _Heap_Protection_block_initialize( heap, block ) ((void) 0)
#define _Heap_Protection_block_check( heap, block ) ((void) 0)
#define _Heap_Protection_block_error( heap, block ) ((void) 0)
#define _Heap_Protection_free_all_delayed_blocks( heap ) ((void) 0)
#else
static inline void _Heap_Protection_block_initialize(
Heap_Control *heap,
Heap_Block *block
)
{
(*heap->Protection.block_initialize)( heap, block );
}
static inline void _Heap_Protection_block_check(
Heap_Control *heap,
Heap_Block *block
)
{
(*heap->Protection.block_check)( heap, block );
}
static inline void _Heap_Protection_block_error(
Heap_Control *heap,
Heap_Block *block
)
{
(*heap->Protection.block_error)( heap, block );
}
static inline void _Heap_Protection_free_all_delayed_blocks( Heap_Control *heap )
{
uintptr_t large = 0
- (uintptr_t) HEAP_BLOCK_HEADER_SIZE
- (uintptr_t) HEAP_ALLOC_BONUS
- (uintptr_t) 1;
void *p = _Heap_Allocate( heap, large );
_Heap_Free( heap, p );
}
#endif
/**
* @brief Sets the fraction of delayed free blocks that is actually freed
* during memory shortage.
*
* The default is to free half the delayed free blocks. This is equal to a
* fraction value of two.
*
* @param[in] heap The heap control.
* @param[in] fraction The fraction is one divided by this fraction value.
*/
RTEMS_INLINE_ROUTINE void _Heap_Protection_set_delayed_free_fraction(
Heap_Control *heap,
uintptr_t fraction
)
{
#ifdef HEAP_PROTECTION
heap->Protection.delayed_free_fraction = fraction;
#else
(void) heap;
(void) fraction;
#endif
}
RTEMS_INLINE_ROUTINE Heap_Block *_Heap_Free_list_head( Heap_Control *heap )
{
return &heap->free_list;
}
RTEMS_INLINE_ROUTINE Heap_Block *_Heap_Free_list_tail( Heap_Control *heap )
{
return &heap->free_list;
}
RTEMS_INLINE_ROUTINE Heap_Block *_Heap_Free_list_first( Heap_Control *heap )
{
return _Heap_Free_list_head(heap)->next;
}
RTEMS_INLINE_ROUTINE Heap_Block *_Heap_Free_list_last( Heap_Control *heap )
{
return _Heap_Free_list_tail(heap)->prev;
}
RTEMS_INLINE_ROUTINE void _Heap_Free_list_remove( Heap_Block *block )
{
Heap_Block *next = block->next;
Heap_Block *prev = block->prev;
prev->next = next;
next->prev = prev;
}
RTEMS_INLINE_ROUTINE void _Heap_Free_list_replace(
Heap_Block *old_block,
Heap_Block *new_block
)
{
Heap_Block *next = old_block->next;
Heap_Block *prev = old_block->prev;
new_block->next = next;
new_block->prev = prev;
next->prev = new_block;
prev->next = new_block;
}
RTEMS_INLINE_ROUTINE void _Heap_Free_list_insert_after(
Heap_Block *block_before,
Heap_Block *new_block
)
{
Heap_Block *next = block_before->next;
new_block->next = next;
new_block->prev = block_before;
block_before->next = new_block;
next->prev = new_block;
}
RTEMS_INLINE_ROUTINE void _Heap_Free_list_insert_before(
Heap_Block *block_next,
Heap_Block *new_block
)
{
Heap_Block *prev = block_next->prev;
new_block->next = block_next;
new_block->prev = prev;
prev->next = new_block;
block_next->prev = new_block;
}
RTEMS_INLINE_ROUTINE bool _Heap_Is_aligned(
uintptr_t value,
uintptr_t alignment
)
{
return (value % alignment) == 0;
}
RTEMS_INLINE_ROUTINE uintptr_t _Heap_Align_down(
uintptr_t value,
uintptr_t alignment
)
{
return value - (value % alignment);
}
/**
* @brief Returns the block which is @a offset away from @a block.
*/
RTEMS_INLINE_ROUTINE Heap_Block *_Heap_Block_at(
const Heap_Block *block,
uintptr_t offset
)
{
return (Heap_Block *) ((uintptr_t) block + offset);
}
RTEMS_INLINE_ROUTINE Heap_Block *_Heap_Prev_block(
const Heap_Block *block
)
{
return (Heap_Block *) ((uintptr_t) block - block->prev_size);
}
RTEMS_INLINE_ROUTINE uintptr_t _Heap_Alloc_area_of_block(
const Heap_Block *block
)
{
return (uintptr_t) block + HEAP_BLOCK_HEADER_SIZE;
}
RTEMS_INLINE_ROUTINE Heap_Block *_Heap_Block_of_alloc_area(
uintptr_t alloc_begin,
uintptr_t page_size
)
{
return (Heap_Block *) (_Heap_Align_down( alloc_begin, page_size )
- HEAP_BLOCK_HEADER_SIZE);
}
RTEMS_INLINE_ROUTINE uintptr_t _Heap_Block_size( const Heap_Block *block )
{
return block->size_and_flag & ~HEAP_PREV_BLOCK_USED;
}
RTEMS_INLINE_ROUTINE void _Heap_Block_set_size(
Heap_Block *block,
uintptr_t size
)
{
uintptr_t flag = block->size_and_flag & HEAP_PREV_BLOCK_USED;
block->size_and_flag = size | flag;
}
RTEMS_INLINE_ROUTINE bool _Heap_Is_prev_used( const Heap_Block *block )
{
return block->size_and_flag & HEAP_PREV_BLOCK_USED;
}
RTEMS_INLINE_ROUTINE bool _Heap_Is_used(
const Heap_Block *block
)
{
const Heap_Block *const next_block =
_Heap_Block_at( block, _Heap_Block_size( block ) );
return _Heap_Is_prev_used( next_block );
}
RTEMS_INLINE_ROUTINE bool _Heap_Is_free(
const Heap_Block *block
)
{
return !_Heap_Is_used( block );
}
RTEMS_INLINE_ROUTINE bool _Heap_Is_block_in_heap(
const Heap_Control *heap,
const Heap_Block *block
)
{
return (uintptr_t) block >= (uintptr_t) heap->first_block
&& (uintptr_t) block <= (uintptr_t) heap->last_block;
}
/**
* @brief Sets the size of the last block for heap @a heap.
*
* The next block of the last block will be the first block. Since the first
* block indicates that the previous block is used, this ensures that the last
* block appears as used for the _Heap_Is_used() and _Heap_Is_free()
* functions.
*
* This feature will be used to terminate the scattered heap area list. See
* also _Heap_Extend().
*/
RTEMS_INLINE_ROUTINE void _Heap_Set_last_block_size( Heap_Control *heap )
{
_Heap_Block_set_size(
heap->last_block,
(uintptr_t) heap->first_block - (uintptr_t) heap->last_block
);
}
/**
* @brief Returns the size of the allocatable area in bytes.
*
* This value is an integral multiple of the page size.
*/
RTEMS_INLINE_ROUTINE uintptr_t _Heap_Get_size( const Heap_Control *heap )
{
return heap->stats.size;
}
RTEMS_INLINE_ROUTINE uintptr_t _Heap_Max( uintptr_t a, uintptr_t b )
{
return a > b ? a : b;
}
RTEMS_INLINE_ROUTINE uintptr_t _Heap_Min( uintptr_t a, uintptr_t b )
{
return a < b ? a : b;
}
#ifdef RTEMS_DEBUG
#define RTEMS_HEAP_DEBUG
#endif
#ifdef RTEMS_HEAP_DEBUG
#include <assert.h>
#define _HAssert( cond ) \
do { \
if ( !(cond) ) { \
__assert( __FILE__, __LINE__, #cond ); \
} \
} while (0)
#else
#define _HAssert( cond ) ((void) 0)
#endif
/** @} */
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
