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/**
* @file rtems/score/priority.h
*
* @brief Thread Priority Manipulation Routines
*
* This include file contains all thread priority manipulation routines.
* This Handler provides mechanisms which can be used to
* initialize and manipulate thread priorities.
*/
/*
* COPYRIGHT (c) 1989-2011.
* 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.
*/
#ifndef _RTEMS_SCORE_PRIORITY_H
#define _RTEMS_SCORE_PRIORITY_H
/**
* @defgroup ScorePriority Priority Handler
*
* @ingroup Score
*
* This handler encapsulates functionality which is used to manage
* thread priorities. At the SuperCore level 256 priority levels
* are supported with lower numbers representing logically more important
* threads. The priority level 0 is reserved for internal RTEMS use.
* Typically it is assigned to threads which defer internal RTEMS
* actions from an interrupt to thread level to improve interrupt response.
* Priority level 255 is assigned to the IDLE thread and really should not
* be used by application threads. The default IDLE thread implementation
* is an infinite "branch to self" loop which never yields to other threads
* at the same priority.
*/
/**@{*/
/*
* Processor specific information.
*/
#include <rtems/score/cpu.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* The following type defines the control block used to manage
* thread priorities.
*
* @note Priority 0 is reserved for internal threads only.
*/
typedef uint32_t Priority_Control;
/** This defines the highest (most important) thread priority. */
#define PRIORITY_MINIMUM 0
/** This defines the default lowest (least important) thread priority. */
#if defined (CPU_PRIORITY_MAXIMUM)
#define PRIORITY_DEFAULT_MAXIMUM CPU_PRIORITY_MAXIMUM
#else
#define PRIORITY_DEFAULT_MAXIMUM 255
#endif
/** This defines the lowest (least important) thread priority. */
#define PRIORITY_MAXIMUM rtems_maximum_priority
/**
* This variable contains the configured number of priorities
*/
extern uint8_t rtems_maximum_priority;
#ifndef __RTEMS_APPLICATION__
#include <rtems/score/priority.inl>
#endif
#ifdef __cplusplus
}
#endif
/**@}*/
#endif
/* end of include file */
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