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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