/* 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.
*
* $Id$
*/
#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 */
