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/**
* @file
*
* @brief POSIX Priority Support
*
* This include file defines the interface to the POSIX priority
* implementation.
*/
/*
* 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.org/license/LICENSE.
*/
#ifndef _RTEMS_POSIX_PRIORITYIMPL_H
#define _RTEMS_POSIX_PRIORITYIMPL_H
#include <rtems/score/scheduler.h>
#include <rtems/score/assert.h>
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup POSIX_PRIORITY POSIX Priority Support
*
* @ingroup POSIXAPI
*
* @brief Interface to the POSIX Priority Implementation.
*
* @{
*/
/**
* This is the numerically least important POSIX priority.
*/
#define POSIX_SCHEDULER_MINIMUM_PRIORITY (1)
/**
* @brief Gets the maximum POSIX API priority for this scheduler instance.
*
* Such a priority is valid. A scheduler instance may support priority values
* that are not representable as an integer.
*
* @return The maximum POSIX API priority for this scheduler instance.
*/
RTEMS_INLINE_ROUTINE int _POSIX_Priority_Get_maximum(
const Scheduler_Control *scheduler
)
{
_Assert( (int) scheduler->maximum_priority > 1 );
return (int) scheduler->maximum_priority - 1;
}
/**
* @brief Converts the POSIX API priority to the corresponding SuperCore
* priority and validates it.
*
* According to POSIX, numerically higher values represent higher priorities.
* Thus, SuperCore has priorities run in the opposite sense of the POSIX API.
*
* Let N be the maximum priority of this scheduler instance. The SuperCore
* priority zero is system reserved (PRIORITY_PSEUDO_ISR). There are only
* N - 1 POSIX API priority levels since a thread at SuperCore priority N would
* never run because of the idle threads. This is necessary because GNAT maps
* the lowest Ada task priority to the lowest thread priority. The lowest
* priority Ada task should get to run, so there is a fundamental conflict with
* having N priorities.
*
* @param[in] scheduler The scheduler instance.
* @param[in] priority The POSIX API priority to convert and validate.
* @param[out] valid Indicates if the POSIX API priority is valid and a
* corresponding SuperCore priority in the specified scheduler instance
* exists.
*
* @return The corresponding SuperCore priority.
*/
Priority_Control _POSIX_Priority_To_core(
const Scheduler_Control *scheduler,
int priority,
bool *valid
);
/**
* @brief Converts the SuperCore priority to the corresponding POSIX API
* priority.
*
* @param[in] scheduler The scheduler instance.
* @param[in] priority The SuperCore priority to convert.
*
* @return The corresponding POSIX API priority.
*/
int _POSIX_Priority_From_core(
const Scheduler_Control *scheduler,
Priority_Control priority
);
/** @} */
#ifdef __cplusplus
}
#endif
#endif
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