path: root/cpukit/rtems/include/rtems/rtems/semimpl.h

/**
 * @file
 *
 * @ingroup ClassicSem
 *
 * @brief Classic Semaphores 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_RTEMS_SEMIMPL_H
#define _RTEMS_RTEMS_SEMIMPL_H

#include <rtems/rtems/sem.h>
#include <rtems/score/coremuteximpl.h>
#include <rtems/score/coresemimpl.h>
#include <rtems/score/mrspimpl.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief Classic semaphore variants.
 *
 * Must be in synchronization with Semaphore_Control::variant.
 */
typedef enum {
  SEMAPHORE_VARIANT_MUTEX_INHERIT_PRIORITY,
  SEMAPHORE_VARIANT_MUTEX_PRIORITY_CEILING,
  SEMAPHORE_VARIANT_MUTEX_NO_PROTOCOL,
  SEMAPHORE_VARIANT_SIMPLE_BINARY,
  SEMAPHORE_VARIANT_COUNTING
#if defined(RTEMS_SMP)
  ,
  SEMAPHORE_VARIANT_MRSP
#endif
} Semaphore_Variant;

typedef enum {
  SEMAPHORE_DISCIPLINE_PRIORITY,
  SEMAPHORE_DISCIPLINE_FIFO
} Semaphore_Discipline;

/**
 *  The following defines the information control block used to manage
 *  this class of objects.
 */
extern Objects_Information _Semaphore_Information;

RTEMS_INLINE_ROUTINE const Thread_queue_Operations *_Semaphore_Get_operations(
  const Semaphore_Control *the_semaphore
)
{
  if ( the_semaphore->variant == SEMAPHORE_VARIANT_MUTEX_INHERIT_PRIORITY ) {
    return &_Thread_queue_Operations_priority_inherit;
  }

  if ( the_semaphore->discipline == SEMAPHORE_DISCIPLINE_PRIORITY ) {
    return &_Thread_queue_Operations_priority;
  }

  return &_Thread_queue_Operations_FIFO;
}

/**
 *  @brief Allocates a semaphore control block from
 *  the inactive chain of free semaphore control blocks.
 *
 *  This function allocates a semaphore control block from
 *  the inactive chain of free semaphore control blocks.
 */
RTEMS_INLINE_ROUTINE Semaphore_Control *_Semaphore_Allocate( void )
{
  return (Semaphore_Control *) _Objects_Allocate( &_Semaphore_Information );
}

/**
 *  @brief Frees a semaphore control block to the
 *  inactive chain of free semaphore control blocks.
 *
 *  This routine frees a semaphore control block to the
 *  inactive chain of free semaphore control blocks.
 */
RTEMS_INLINE_ROUTINE void _Semaphore_Free (
  Semaphore_Control *the_semaphore
)
{
  _Objects_Free( &_Semaphore_Information, &the_semaphore->Object );
}

RTEMS_INLINE_ROUTINE Semaphore_Control *_Semaphore_Get(
  Objects_Id            id,
  Thread_queue_Context *queue_context
)
{
  _Thread_queue_Context_initialize( queue_context );
  return (Semaphore_Control *) _Objects_Get(
    id,
    &queue_context->Lock_context.Lock_context,
    &_Semaphore_Information
  );
}

#ifdef __cplusplus
}
#endif

#ifdef RTEMS_MULTIPROCESSING
#include <rtems/rtems/semmp.h>
#endif

#endif
/*  end of include file */