/* mutex.h
*
* This include file contains all the constants and structures associated
* with the Mutex Handler. A mutex is an enhanced version of the standard
* Dijkstra binary semaphore used to provide synchronization and mutual
* exclusion capabilities.
*
* COPYRIGHT (c) 1989-1998.
* On-Line Applications Research Corporation (OAR).
* Copyright assigned to U.S. Government, 1994.
*
* 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_CORE_MUTEX_h
#define __RTEMS_CORE_MUTEX_h
#ifdef __cplusplus
extern "C" {
#endif
#include <rtems/score/thread.h>
#include <rtems/score/threadq.h>
#include <rtems/score/priority.h>
#include <rtems/score/watchdog.h>
/*
* The following type defines the callout which the API provides
* to support global/multiprocessor operations on mutexes.
*/
typedef void ( *CORE_mutex_API_mp_support_callout )(
Thread_Control *,
Objects_Id
);
/*
* Blocking disciplines for a mutex.
*/
typedef enum {
CORE_MUTEX_DISCIPLINES_FIFO,
CORE_MUTEX_DISCIPLINES_PRIORITY,
CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT,
CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING
} CORE_mutex_Disciplines;
/*
* Mutex handler return statuses.
*/
typedef enum {
CORE_MUTEX_STATUS_SUCCESSFUL,
CORE_MUTEX_STATUS_UNSATISFIED_NOWAIT,
CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED,
CORE_MUTEX_STATUS_NOT_OWNER_OF_RESOURCE,
CORE_MUTEX_WAS_DELETED,
CORE_MUTEX_TIMEOUT,
CORE_MUTEX_STATUS_CEILING_VIOLATED
} CORE_mutex_Status;
/*
* Locked and unlocked values
*/
#define CORE_MUTEX_UNLOCKED 1
#define CORE_MUTEX_LOCKED 0
/*
* The following defines the control block used to manage the
* attributes of each mutex.
*/
typedef struct {
boolean allow_nesting;
CORE_mutex_Disciplines discipline;
Priority_Control priority_ceiling;
} CORE_mutex_Attributes;
/*
* The following defines the control block used to manage each mutex.
*/
typedef struct {
Thread_queue_Control Wait_queue;
CORE_mutex_Attributes Attributes;
unsigned32 lock;
unsigned32 nest_count;
Thread_Control *holder;
Objects_Id holder_id;
} CORE_mutex_Control;
/*
* _CORE_mutex_Initialize
*
* DESCRIPTION:
*
* This routine initializes the mutex based on the parameters passed.
*/
void _CORE_mutex_Initialize(
CORE_mutex_Control *the_mutex,
Objects_Classes the_class,
CORE_mutex_Attributes *the_mutex_attributes,
unsigned32 initial_lock,
Thread_queue_Extract_callout proxy_extract_callout
);
/*
* _CORE_mutex_Seize
*
* DESCRIPTION:
*
* This routine attempts to receive a unit from the_mutex.
* If a unit is available or if the wait flag is FALSE, then the routine
* returns. Otherwise, the calling task is blocked until a unit becomes
* available.
*/
void _CORE_mutex_Seize(
CORE_mutex_Control *the_mutex,
Objects_Id id,
boolean wait,
Watchdog_Interval timeout
);
/*
* _CORE_mutex_Surrender
*
* DESCRIPTION:
*
* This routine frees a unit to the mutex. If a task was blocked waiting for
* a unit from this mutex, then that task will be readied and the unit
* given to that task. Otherwise, the unit will be returned to the mutex.
*/
CORE_mutex_Status _CORE_mutex_Surrender(
CORE_mutex_Control *the_mutex,
Objects_Id id,
CORE_mutex_API_mp_support_callout api_mutex_mp_support
);
/*
* _CORE_mutex_Flush
*
* DESCRIPTION:
*
* This routine assists in the deletion of a mutex by flushing the associated
* wait queue.
*/
void _CORE_mutex_Flush(
CORE_mutex_Control *the_mutex,
Thread_queue_Flush_callout remote_extract_callout,
unsigned32 status
);
#ifndef __RTEMS_APPLICATION__
#include <rtems/score/coremutex.inl>
#endif
#ifdef __cplusplus
}
#endif
#endif
/* end of include file */
