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Diffstat (limited to 'c/src/exec/rtems/include/rtems/rtems/sem.h')
| -rw-r--r-- | c/src/exec/rtems/include/rtems/rtems/sem.h | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/c/src/exec/rtems/include/rtems/rtems/sem.h b/c/src/exec/rtems/include/rtems/rtems/sem.h new file mode 100644 index 0000000000..66f5ab82b8 --- /dev/null +++ b/c/src/exec/rtems/include/rtems/rtems/sem.h @@ -0,0 +1,238 @@ +/* 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, 1990, 1991, 1992, 1993, 1994. + * On-Line Applications Research Corporation (OAR). + * All rights assigned to U.S. Government, 1994. + * + * This material may be reproduced by or for the U.S. Government pursuant + * to the copyright license under the clause at DFARS 252.227-7013. This + * notice must appear in all copies of this file and its derivatives. + * + * $Id$ + */ + +#ifndef __RTEMS_SEMAPHORE_h +#define __RTEMS_SEMAPHORE_h + +#ifdef __cplusplus +extern "C" { +#endif + +#include <rtems/attr.h> +#include <rtems/object.h> +#include <rtems/threadq.h> + +/* + * The following defines the control block used to manage each semaphore. + */ + +typedef struct { + Objects_Control Object; + Thread_queue_Control Wait_queue; + rtems_attribute attribute_set; + unsigned32 count; + unsigned32 nest_count; + Thread_Control *holder; + Objects_Id holder_id; +} Semaphore_Control; + +/* + * The following defines the information control block used to manage + * this class of objects. + */ + +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( + Objects_Name name, + unsigned32 count, + rtems_attribute attribute_set, + Objects_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( + Objects_Name name, + unsigned32 node, + Objects_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( + Objects_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( + Objects_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( + 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_Allocate + * + * DESCRIPTION: + * + * This function allocates a semaphore control block from + * the inactive chain of free semaphore control blocks. + */ + +STATIC INLINE Semaphore_Control *_Semaphore_Allocate( void ); + +/* + * _Semaphore_Free + * + * DESCRIPTION: + * + * This routine frees a semaphore control block to the + * inactive chain of free semaphore control blocks. + */ + +STATIC INLINE void _Semaphore_Free ( + Semaphore_Control *the_semaphore +); + +/* + * _Semaphore_Get + * + * DESCRIPTION: + * + * This function maps semaphore IDs to semaphore control blocks. + * If ID corresponds to a local semaphore, then it returns + * the_semaphore control pointer which maps to ID and location + * is set to OBJECTS_LOCAL. if the semaphore ID is global and + * resides on a remote node, then location is set to OBJECTS_REMOTE, + * and the_semaphore is undefined. Otherwise, location is set + * to OBJECTS_ERROR and the_semaphore is undefined. + */ + +STATIC INLINE Semaphore_Control *_Semaphore_Get ( + Objects_Id id, + Objects_Locations *location +); + +/* + * _Semaphore_Is_null + * + * DESCRIPTION: + * + * This function returns TRUE if the_semaphore is NULL and FALSE otherwise. + */ + +STATIC INLINE boolean _Semaphore_Is_null ( + Semaphore_Control *the_semaphore +); + +#include <rtems/sem.inl> +#include <rtems/semmp.h> + +#ifdef __cplusplus +} +#endif + +#endif +/* end of include file */ |