/**
* @file rtems/rtems/region.h
*
* This include file contains all the constants and structures associated
* with the Region Manager. This manager provides facilities to dynamically
* allocate memory in variable sized units which are returned as segments.
*
* Directives provided are:
*
* - create a region
* - get an ID of a region
* - delete a region
* - get a segment from a region
* - return a segment to a region
*/
/* COPYRIGHT (c) 1989-2009.
* 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.com/license/LICENSE.
*
* $Id$
*/
#ifndef _RTEMS_RTEMS_REGION_H
#define _RTEMS_RTEMS_REGION_H
#include <rtems/score/object.h>
#include <rtems/score/threadq.h>
#include <rtems/score/heap.h>
#include <rtems/debug.h>
#include <rtems/rtems/attr.h>
#include <rtems/rtems/options.h>
#include <rtems/rtems/status.h>
#include <rtems/rtems/support.h>
#include <rtems/rtems/types.h>
/**
* @defgroup ClassicRegion Regions
*
* @ingroup ClassicRTEMS
*
* This encapsulates functionality which XXX
*/
/**@{*/
/**
* This constant is defined to extern most of the time when using
* this header file. However by defining it to nothing, the data
* declared in this header file can be instantiated. This is done
* in a single per manager file.
*/
#ifndef RTEMS_REGION_EXTERN
#define RTEMS_REGION_EXTERN extern
#endif
#ifdef __cplusplus
extern "C" {
#endif
/**
* The following records define the control block used to manage
* each region.
*/
typedef struct {
Objects_Control Object;
Thread_queue_Control Wait_queue; /* waiting threads */
void *starting_address; /* physical start addr */
uintptr_t length; /* physical length(bytes) */
uintptr_t page_size; /* in bytes */
uintptr_t maximum_segment_size; /* in bytes */
rtems_attribute attribute_set;
uint32_t number_of_used_blocks; /* blocks allocated */
Heap_Control Memory;
} Region_Control;
/**
* The following defines the information control block used to
* manage this class of objects.
*/
RTEMS_REGION_EXTERN Objects_Information _Region_Information;
/**
* @brief _Region_Manager_initialization
*
* This routine performs the initialization necessary for this manager.
*/
void _Region_Manager_initialization(void);
/**
* @brief rtems_region_create
*
* This routine implements the rtems_region_create directive. The
* region will have the name name. The memory area managed by
* the region is of length bytes and starts at starting_address.
* The memory area will be divided into as many allocatable units of
* page_size bytes as possible. The attribute_set determines which
* thread queue discipline is used by the region. It returns the
* id of the created region in ID.
*/
rtems_status_code rtems_region_create(
rtems_name name,
void *starting_address,
uintptr_t length,
uintptr_t page_size,
rtems_attribute attribute_set,
rtems_id *id
);
/**
* @brief rtems_region_extend
*
* This routine implements the rtems_region_extend directive. The
* region will have the name name. The memory area managed by
* the region will be attempted to be grown by length bytes using
* the memory starting at starting_address.
*/
rtems_status_code rtems_region_extend(
rtems_id id,
void *starting_address,
uintptr_t length
);
/**
* @brief rtems_region_ident
*
* This routine implements the rtems_region_ident directive.
* This directive returns the region ID associated with name.
* If more than one region is named name, then the region
* to which the ID belongs is arbitrary.
*/
rtems_status_code rtems_region_ident(
rtems_name name,
rtems_id *id
);
/**
* @brief rtems_region_get_information
*
* This routine implements the rtems_region_get_information directive.
* This directive returns information about the heap associated with
* this region.
*/
rtems_status_code rtems_region_get_information(
rtems_id id,
Heap_Information_block *the_info
);
/**
* @brief rtems_region_get_free_information
*
* This routine implements the rtems_region_get_free_information directive.
* This directive returns information about the free blocks in the
* heap associated with this region.
*/
rtems_status_code rtems_region_get_free_information(
rtems_id id,
Heap_Information_block *the_info
);
/**
* @brief rtems_region_delete
*
* This routine implements the rtems_region_delete directive. The
* region indicated by ID is deleted.
*/
rtems_status_code rtems_region_delete(
rtems_id id
);
/**
* @brief rtems_region_get_segment
*
* This routine implements the rtems_region_get_segment directive. It
* attempts to allocate a segment from the region associated with ID.
* If a segment of the requested size can be allocated, its address
* is returned in segment. If no segment is available, then the task
* may return immediately or block waiting for a segment with an optional
* timeout of timeout clock ticks. Whether the task blocks or returns
* immediately is based on the no_wait option in the option_set.
*/
rtems_status_code rtems_region_get_segment(
rtems_id id,
uintptr_t size,
rtems_option option_set,
rtems_interval timeout,
void **segment
);
/**
* @brief rtems_region_get_segment_size
*
* This routine implements the rtems_region_get_segment_size directive. It
* returns the size in bytes of the specified user memory area.
*/
rtems_status_code rtems_region_get_segment_size(
rtems_id id,
void *segment,
uintptr_t *size
);
/**
* @brief rtems_region_return_segment
*
* This routine implements the rtems_region_return_segment directive. It
* frees the segment to the region associated with ID. The segment must
* have been previously allocated from the same region. If freeing the
* segment results in enough memory being available to satisfy the
* rtems_region_get_segment of the first blocked task, then that task and as
* many subsequent tasks as possible will be unblocked with their requests
* satisfied.
*/
rtems_status_code rtems_region_return_segment(
rtems_id id,
void *segment
);
/**
* @brief rtems_region_resize_segment
*
* This routine implements the rtems_region_resize_segment directive. It
* tries to resize segment in the region associated with 'id' to the new size
* 'size' in place. The first 'size' or old size bytes of the segment
* (whatever is less) are guaranteed to remain unmodified. The segment must
* have been previously allocated from the same region. If resizing the
* segment results in enough memory being available to satisfy the
* rtems_region_get_segment of the first blocked task, then that task and as
* many subsequent tasks as possible will be unblocked with their requests
* satisfied.
* Returns:
* RTEMS_SUCCESSFUL - operation successful
* RTEMS_UNSATISFIED - the segment can't be resized in place
* any other code - failure.
* On RTEMS_SUCCESSFUL or RTEMS_UNSATISFIED exit it returns into the
* 'old_size' the old size in bytes of the user memory area of the specified
* segment.
*/
rtems_status_code rtems_region_resize_segment(
rtems_id id,
void *segment,
uintptr_t size,
uintptr_t *old_size
);
#ifndef __RTEMS_APPLICATION__
#include <rtems/rtems/region.inl>
/**
* @brief Region_Process_queue
*
* This is a helper routine which is invoked any time memory is
* freed. It looks at the set of waiting tasks and attempts to
* satisfy all outstanding requests.
*/
extern void _Region_Process_queue(Region_Control *the_region);
#endif
#if defined(RTEMS_MULTIPROCESSING)
#include <rtems/rtems/regionmp.h>
#endif
/**
* @brief _Region_Debug_Walk
*
* This routine is invoked to verify the integrity of a heap associated
* with the_region.
*/
#ifdef RTEMS_DEBUG
#define _Region_Debug_Walk( _the_region, _source ) \
do { \
if ( rtems_debug_is_enabled( RTEMS_DEBUG_REGION ) ) \
_Heap_Walk( &(_the_region)->Memory, _source, false ); \
} while ( 0 )
#else
#define _Region_Debug_Walk( _the_region, _source )
#endif
#ifdef __cplusplus
}
#endif
/**@}*/
#endif
/* end of include file */
