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/*  semaphore.h

 *

 *  This include file contains all the constants and structures associated

 *  with the Semaphore Manager.  This manager utilizes standard Dijkstra

 *  counting semaphores to provide synchronization and mutual exclusion

 *  capabilities.

 *

 *  Directives provided are:

 *

 *     + create a semaphore

 *     + get an ID of a semaphore

 *     + delete a semaphore

 *     + acquire a semaphore

 *     + release a semaphore

 *

 *  COPYRIGHT (c) 1989-1999.

 *  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.OARcorp.com/rtems/license.html.

 *

 *  $Id: sem.h,v 1.2 2001-09-27 11:59:18 chris Exp $

 */

#ifndef __RTEMS_SEMAPHORE_h

#define __RTEMS_SEMAPHORE_h

#ifdef __cplusplus

extern "C" {

#endif

#include <rtems/rtems/types.h>

#include <rtems/rtems/support.h>

#include <rtems/rtems/tasks.h>

#include <rtems/rtems/attr.h>

#include <rtems/score/coremutex.h>

#include <rtems/score/object.h>

#include <rtems/score/coresem.h>

#include <rtems/score/threadq.h>

/*

 *  The following defines the control block used to manage each semaphore.

 */

typedef struct {

  Objects_Control          Object;

  rtems_attribute          attribute_set;

  union {

    CORE_mutex_Control     mutex;

    CORE_semaphore_Control semaphore;

  } Core_control;

}   Semaphore_Control;

/*

 *  The following defines the information control block used to manage

 *  this class of objects.

 */

RTEMS_EXTERN Objects_Information  _Semaphore_Information;

/*

 *  _Semaphore_Manager_initialization

 *

 *  DESCRIPTION:

 *

 *  This routine performs the initialization necessary for this manager.

 */

void _Semaphore_Manager_initialization(

  unsigned32 maximum_semaphores

);

/*

 *  rtems_semaphore_create

 *

 *  DESCRIPTION:

 *

 *  This routine implements the rtems_semaphore_create directive.  The

 *  semaphore will have the name name.  The starting count for

 *  the semaphore is count.  The attribute_set determines if

 *  the semaphore is global or local and the thread queue

 *  discipline.  It returns the id of the created semaphore in ID.

 */

rtems_status_code rtems_semaphore_create(

  rtems_name           name,

  unsigned32           count,

  rtems_attribute      attribute_set,

  rtems_task_priority  priority_ceiling,

  rtems_id            *id

);

/*

 *  rtems_semaphore_ident

 *

 *  DESCRIPTION:

 *

 *  This routine implements the rtems_semaphore_ident directive.

 *  This directive returns the semaphore ID associated with name.

 *  If more than one semaphore is named name, then the semaphore

 *  to which the ID belongs is arbitrary.  node indicates the

 *  extent of the search for the ID of the semaphore named name.

 *  The search can be limited to a particular node or allowed to

 *  encompass all nodes.

 */

rtems_status_code rtems_semaphore_ident(

  rtems_name    name,

  unsigned32    node,

  rtems_id     *id

);

/*

 *  rtems_semaphore_delete

 *

 *  DESCRIPTION:

 *

 *  This routine implements the rtems_semaphore_delete directive.  The

 *  semaphore indicated by ID is deleted.

 */

rtems_status_code rtems_semaphore_delete(

  rtems_id   id

);

/*

 *  rtems_semaphore_obtain

 *

 *  DESCRIPTION:

 *

 *  This routine implements the rtems_semaphore_obtain directive.  It

 *  attempts to obtain a unit from the semaphore associated with ID.

 *  If a unit can be allocated, the calling task will return immediately.

 *  If no unit is available, then the task may return immediately or

 *  block waiting for a unit with an optional timeout of timeout

 *  clock ticks.  Whether the task blocks or returns immediately

 *  is based on the RTEMS_NO_WAIT option in the option_set.

 */

rtems_status_code rtems_semaphore_obtain(

  rtems_id       id,

  unsigned32     option_set,

  rtems_interval timeout

);

/*

 *  rtems_semaphore_release

 *

 *  DESCRIPTION:

 *

 *  This routine implements the rtems_semaphore_release directive.  It

 *  frees a unit to the semaphore associated with ID.  If a task was

 *  blocked waiting for a unit from this semaphore, then that task will

 *  be readied and the unit given to that task.  Otherwise, the unit

 *  will be returned to the semaphore.

 */

rtems_status_code rtems_semaphore_release(

  rtems_id   id

);

/*

 *  rtems_semaphore_flush

 *

 *  This directive allows a thread to flush the threads

 *  pending on the semaphore.

 */

rtems_status_code rtems_semaphore_flush(

  Objects_Id      id

);

/*

 *  _Semaphore_Seize

 *

 *  DESCRIPTION:

 *

 *  This routine attempts to receive a unit from the_semaphore.

 *  If a unit is available or if the RTEMS_NO_WAIT option is enabled in

 *  option_set, then the routine returns.  Otherwise, the calling task

 *  is blocked until a unit becomes available.

 */

boolean _Semaphore_Seize(

  Semaphore_Control *the_semaphore,

  unsigned32         option_set

);

/*

 *  _Semaphore_Translate_core_mutex_return_code

 *

 *  DESCRIPTION:

 *

 *  This function returns a RTEMS status code based on the mutex

 *  status code specified.

 */

rtems_status_code _Semaphore_Translate_core_mutex_return_code (

  unsigned32 the_mutex_status

);

/*

 *  _Semaphore_Translate_core_semaphore_return_code

 *

 *  DESCRIPTION:

 *

 *  This function returns a RTEMS status code based on the semaphore

 *  status code specified.

 */

rtems_status_code _Semaphore_Translate_core_semaphore_return_code (

  unsigned32 the_mutex_status

);

/*PAGE

 *

 *  _Semaphore_Core_mutex_mp_support

 *

 *  DESCRIPTION:

 *

 *  This function processes the global actions necessary for remote

 *  accesses to a global semaphore based on a core mutex.  This function

 *  is called by the core.

 */

#if defined(RTEMS_MULTIPROCESSING)

void  _Semaphore_Core_mutex_mp_support (

  Thread_Control *the_thread,

  rtems_id        id

);

#endif

/*PAGE

 *

 *  _Semaphore_Core_mp_support

 *

 *  DESCRIPTION:

 *

 *  This function processes the global actions necessary for remote

 *  accesses to a global semaphore based on a core semaphore.  This function

 *  is called by the core.

 */

void  _Semaphore_Core_semaphore_mp_support (

  Thread_Control *the_thread,

  rtems_id        id

);

/*PAGE

 *

 *  _POSIX_Semaphore_MP_support

 *

 *  DESCRIPTION:

 *

 *  XXX

 */

void _POSIX_Semaphore_MP_support(

  Thread_Control *the_thread,

  Objects_Id      id

);

#ifndef __RTEMS_APPLICATION__

#include <rtems/rtems/sem.inl>

#endif

#if defined(RTEMS_MULTIPROCESSING)

#include <rtems/rtems/semmp.h>

#endif

#ifdef __cplusplus

}

#endif

#endif

/*  end of include file */