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Diffstat (limited to 'c/src/exec/rtems/src/semcreate.c')
| -rw-r--r-- | c/src/exec/rtems/src/semcreate.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/c/src/exec/rtems/src/semcreate.c b/c/src/exec/rtems/src/semcreate.c new file mode 100644 index 0000000000..80b8d21334 --- /dev/null +++ b/c/src/exec/rtems/src/semcreate.c @@ -0,0 +1,203 @@ +/* + * Semaphore Manager + * + * DESCRIPTION: + * + * This package is the implementation of 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) 1989-1998. + * 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. + * + * $Id$ + */ + +#include <rtems/system.h> +#include <rtems/rtems/status.h> +#include <rtems/rtems/support.h> +#include <rtems/rtems/attr.h> +#include <rtems/score/isr.h> +#include <rtems/score/object.h> +#include <rtems/rtems/options.h> +#include <rtems/rtems/sem.h> +#include <rtems/score/coremutex.h> +#include <rtems/score/coresem.h> +#include <rtems/score/states.h> +#include <rtems/score/thread.h> +#include <rtems/score/threadq.h> +#if defined(RTEMS_MULTIPROCESSING) +#include <rtems/score/mpci.h> +#endif +#include <rtems/score/sysstate.h> + +#include <rtems/score/interr.h> + +/*PAGE + * + * rtems_semaphore_create + * + * This directive creates a semaphore and sets the initial value based + * on the given count. A semaphore id is returned. + * + * Input parameters: + * name - user defined semaphore name + * count - initial count of semaphore + * attribute_set - semaphore attributes + * priority_ceiling - semaphore's ceiling priority + * id - pointer to semaphore id + * + * Output parameters: + * id - semaphore id + * RTEMS_SUCCESSFUL - if successful + * error code - if unsuccessful + */ + +rtems_status_code rtems_semaphore_create( + rtems_name name, + unsigned32 count, + rtems_attribute attribute_set, + rtems_task_priority priority_ceiling, + Objects_Id *id +) +{ + register Semaphore_Control *the_semaphore; + CORE_mutex_Attributes the_mutex_attributes; + CORE_semaphore_Attributes the_semaphore_attributes; + unsigned32 lock; + + if ( !rtems_is_name_valid( name ) ) + return RTEMS_INVALID_NAME; + +#if defined(RTEMS_MULTIPROCESSING) + if ( _Attributes_Is_global( attribute_set ) ) { + + if ( !_System_state_Is_multiprocessing ) + return RTEMS_MP_NOT_CONFIGURED; + + if ( _Attributes_Is_inherit_priority( attribute_set ) ) + return RTEMS_NOT_DEFINED; + + } else +#endif + if ( _Attributes_Is_inherit_priority( attribute_set ) || + _Attributes_Is_priority_ceiling( attribute_set ) ) { + + if ( ! ( _Attributes_Is_binary_semaphore( attribute_set ) && + _Attributes_Is_priority( attribute_set ) ) ) + return RTEMS_NOT_DEFINED; + + } + + if ( _Attributes_Is_binary_semaphore( attribute_set ) && ( count > 1 ) ) + return RTEMS_INVALID_NUMBER; + + _Thread_Disable_dispatch(); /* prevents deletion */ + + the_semaphore = _Semaphore_Allocate(); + + if ( !the_semaphore ) { + _Thread_Enable_dispatch(); + return RTEMS_TOO_MANY; + } + +#if defined(RTEMS_MULTIPROCESSING) + if ( _Attributes_Is_global( attribute_set ) && + ! ( _Objects_MP_Allocate_and_open( &_Semaphore_Information, name, + the_semaphore->Object.id, FALSE ) ) ) { + _Semaphore_Free( the_semaphore ); + _Thread_Enable_dispatch(); + return RTEMS_TOO_MANY; + } +#endif + + the_semaphore->attribute_set = attribute_set; + + if ( _Attributes_Is_binary_semaphore( attribute_set ) ) { + if ( _Attributes_Is_inherit_priority( attribute_set ) ) + the_mutex_attributes.discipline = CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT; + else if (_Attributes_Is_priority_ceiling( attribute_set ) ) + the_mutex_attributes.discipline = CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING; + else if (_Attributes_Is_priority( attribute_set ) ) + the_mutex_attributes.discipline = CORE_MUTEX_DISCIPLINES_PRIORITY; + else + the_mutex_attributes.discipline = CORE_MUTEX_DISCIPLINES_FIFO; + + the_mutex_attributes.allow_nesting = TRUE; + + /* Add priority ceiling code here ????? */ + + the_mutex_attributes.priority_ceiling = priority_ceiling; + + if ( count == 1 ) + lock = CORE_MUTEX_UNLOCKED; + else + lock = CORE_MUTEX_LOCKED; + + _CORE_mutex_Initialize( + &the_semaphore->Core_control.mutex, + OBJECTS_RTEMS_SEMAPHORES, + &the_mutex_attributes, + lock, +#if defined(RTEMS_MULTIPROCESSING) + _Semaphore_MP_Send_extract_proxy +#else + NULL +#endif + ); + } + else { + if ( _Attributes_Is_priority( attribute_set ) ) + the_semaphore_attributes.discipline = CORE_SEMAPHORE_DISCIPLINES_PRIORITY; + else + the_semaphore_attributes.discipline = CORE_SEMAPHORE_DISCIPLINES_FIFO; + + /* + * The following are just to make Purify happy. + */ + + the_mutex_attributes.allow_nesting = TRUE; + the_mutex_attributes.priority_ceiling = PRIORITY_MINIMUM; + + _CORE_semaphore_Initialize( + &the_semaphore->Core_control.semaphore, + OBJECTS_RTEMS_SEMAPHORES, + &the_semaphore_attributes, + count, +#if defined(RTEMS_MULTIPROCESSING) + _Semaphore_MP_Send_extract_proxy +#else + NULL +#endif + ); + } + + _Objects_Open( &_Semaphore_Information, &the_semaphore->Object, &name ); + + *id = the_semaphore->Object.id; + +#if defined(RTEMS_MULTIPROCESSING) + if ( _Attributes_Is_global( attribute_set ) ) + _Semaphore_MP_Send_process_packet( + SEMAPHORE_MP_ANNOUNCE_CREATE, + the_semaphore->Object.id, + name, + 0 /* Not used */ + ); +#endif + _Thread_Enable_dispatch(); + return RTEMS_SUCCESSFUL; +} |