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Diffstat (limited to 'cpukit/rtems/src/sem.c')
| -rw-r--r-- | cpukit/rtems/src/sem.c | 571 |
1 files changed, 571 insertions, 0 deletions
diff --git a/cpukit/rtems/src/sem.c b/cpukit/rtems/src/sem.c new file mode 100644 index 0000000000..553750a924 --- /dev/null +++ b/cpukit/rtems/src/sem.c @@ -0,0 +1,571 @@ +/* + * 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) 1989-1997. + * On-Line Applications Research Corporation (OAR). + * Copyright assigned to U.S. Government, 1994. + * + * The license and distribution terms for this file may 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> +#include <rtems/score/mpci.h> +#include <rtems/score/sysstate.h> + +#include <rtems/score/interr.h> + +/*PAGE + * + * _Semaphore_Manager_initialization + * + * This routine initializes all semaphore manager related data structures. + * + * Input parameters: + * maximum_semaphores - maximum configured semaphores + * + * Output parameters: NONE + */ + +void _Semaphore_Manager_initialization( + unsigned32 maximum_semaphores +) +{ + _Objects_Initialize_information( + &_Semaphore_Information, + OBJECTS_RTEMS_SEMAPHORES, + TRUE, + maximum_semaphores, + sizeof( Semaphore_Control ), + FALSE, + RTEMS_MAXIMUM_NAME_LENGTH, + FALSE + ); + + /* + * Register the MP Process Packet routine. + */ + + _MPCI_Register_packet_processor( + MP_PACKET_SEMAPHORE, + _Semaphore_MP_Process_packet + ); + +} + +/*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 ( _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 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 ( _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; + } + + 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, + _Semaphore_MP_Send_extract_proxy + ); + } + 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, + _Semaphore_MP_Send_extract_proxy + ); + } + + _Objects_Open( &_Semaphore_Information, &the_semaphore->Object, &name ); + + *id = the_semaphore->Object.id; + + if ( _Attributes_Is_global( attribute_set ) ) + _Semaphore_MP_Send_process_packet( + SEMAPHORE_MP_ANNOUNCE_CREATE, + the_semaphore->Object.id, + name, + 0 /* Not used */ + ); + _Thread_Enable_dispatch(); + return RTEMS_SUCCESSFUL; +} + +/*PAGE + * + * rtems_semaphore_ident + * + * This directive returns the system ID associated with + * the semaphore name. + * + * Input parameters: + * name - user defined semaphore name + * node - node(s) to be searched + * id - pointer to semaphore id + * + * Output parameters: + * *id - semaphore id + * RTEMS_SUCCESSFUL - if successful + * error code - if unsuccessful + */ + +rtems_status_code rtems_semaphore_ident( + rtems_name name, + unsigned32 node, + Objects_Id *id +) +{ + Objects_Name_to_id_errors status; + + status = _Objects_Name_to_id( &_Semaphore_Information, &name, node, id ); + + return _Status_Object_name_errors_to_status[ status ]; +} + +/*PAGE + * + * rtems_semaphore_delete + * + * This directive allows a thread to delete a semaphore specified by + * the semaphore id. The semaphore is freed back to the inactive + * semaphore chain. + * + * Input parameters: + * id - semaphore id + * + * Output parameters: + * RTEMS_SUCCESSFUL - if successful + * error code - if unsuccessful + */ + +rtems_status_code rtems_semaphore_delete( + Objects_Id id +) +{ + register Semaphore_Control *the_semaphore; + Objects_Locations location; + + the_semaphore = _Semaphore_Get( id, &location ); + switch ( location ) { + case OBJECTS_ERROR: + return RTEMS_INVALID_ID; + case OBJECTS_REMOTE: + _Thread_Dispatch(); + return RTEMS_ILLEGAL_ON_REMOTE_OBJECT; + case OBJECTS_LOCAL: + if ( _Attributes_Is_binary_semaphore( the_semaphore->attribute_set) ) { + if ( _CORE_mutex_Is_locked( &the_semaphore->Core_control.mutex ) ) { + _Thread_Enable_dispatch(); + return RTEMS_RESOURCE_IN_USE; + } + else + _CORE_mutex_Flush( + &the_semaphore->Core_control.mutex, + _Semaphore_MP_Send_object_was_deleted, + CORE_MUTEX_WAS_DELETED + ); + } + else + _CORE_semaphore_Flush( + &the_semaphore->Core_control.semaphore, + _Semaphore_MP_Send_object_was_deleted, + CORE_SEMAPHORE_WAS_DELETED + ); + + _Objects_Close( &_Semaphore_Information, &the_semaphore->Object ); + + _Semaphore_Free( the_semaphore ); + + if ( _Attributes_Is_global( the_semaphore->attribute_set ) ) { + + _Objects_MP_Close( &_Semaphore_Information, the_semaphore->Object.id ); + + _Semaphore_MP_Send_process_packet( + SEMAPHORE_MP_ANNOUNCE_DELETE, + the_semaphore->Object.id, + 0, /* Not used */ + 0 /* Not used */ + ); + } + _Thread_Enable_dispatch(); + return RTEMS_SUCCESSFUL; + } + + return RTEMS_INTERNAL_ERROR; /* unreached - only to remove warnings */ +} + +/*PAGE + * + * rtems_semaphore_obtain + * + * This directive allows a thread to acquire a semaphore. + * + * Input parameters: + * id - semaphore id + * option_set - wait option + * timeout - number of ticks to wait (0 means wait forever) + * + * Output parameters: + * RTEMS_SUCCESSFUL - if successful + * error code - if unsuccessful + */ + +rtems_status_code rtems_semaphore_obtain( + Objects_Id id, + unsigned32 option_set, + rtems_interval timeout +) +{ + register Semaphore_Control *the_semaphore; + Objects_Locations location; + boolean wait; + + the_semaphore = _Semaphore_Get( id, &location ); + switch ( location ) { + case OBJECTS_ERROR: + return RTEMS_INVALID_ID; + case OBJECTS_REMOTE: + return _Semaphore_MP_Send_request_packet( + SEMAPHORE_MP_OBTAIN_REQUEST, + id, + option_set, + timeout + ); + case OBJECTS_LOCAL: + if ( _Options_Is_no_wait( option_set ) ) + wait = FALSE; + else + wait = TRUE; + + if ( _Attributes_Is_binary_semaphore( the_semaphore->attribute_set ) ) { + _CORE_mutex_Seize( + &the_semaphore->Core_control.mutex, + id, + wait, + timeout + ); + _Thread_Enable_dispatch(); + return _Semaphore_Translate_core_mutex_return_code( + _Thread_Executing->Wait.return_code ); + } else { + _CORE_semaphore_Seize( + &the_semaphore->Core_control.semaphore, + id, + wait, + timeout + ); + _Thread_Enable_dispatch(); + return _Semaphore_Translate_core_semaphore_return_code( + _Thread_Executing->Wait.return_code ); + } + } + + return RTEMS_INTERNAL_ERROR; /* unreached - only to remove warnings */ +} + +/*PAGE + * + * rtems_semaphore_release + * + * This directive allows a thread to release a semaphore. + * + * Input parameters: + * id - semaphore id + * + * Output parameters: + * RTEMS_SUCCESSFUL - if successful + * error code - if unsuccessful + */ + +rtems_status_code rtems_semaphore_release( + Objects_Id id +) +{ + register Semaphore_Control *the_semaphore; + Objects_Locations location; + CORE_mutex_Status mutex_status; + CORE_semaphore_Status semaphore_status; + + the_semaphore = _Semaphore_Get( id, &location ); + switch ( location ) { + case OBJECTS_ERROR: + return RTEMS_INVALID_ID; + case OBJECTS_REMOTE: + return _Semaphore_MP_Send_request_packet( + SEMAPHORE_MP_RELEASE_REQUEST, + id, + 0, /* Not used */ + MPCI_DEFAULT_TIMEOUT + ); + case OBJECTS_LOCAL: + if ( _Attributes_Is_binary_semaphore( the_semaphore->attribute_set ) ) { + mutex_status = _CORE_mutex_Surrender( + &the_semaphore->Core_control.mutex, + id, + _Semaphore_Core_mutex_mp_support + ); + _Thread_Enable_dispatch(); + return _Semaphore_Translate_core_mutex_return_code( mutex_status ); + } + else + semaphore_status = _CORE_semaphore_Surrender( + &the_semaphore->Core_control.semaphore, + id, + _Semaphore_Core_semaphore_mp_support + ); + _Thread_Enable_dispatch(); + return + _Semaphore_Translate_core_semaphore_return_code( semaphore_status ); + } + + return RTEMS_INTERNAL_ERROR; /* unreached - only to remove warnings */ +} + +/*PAGE + * + * _Semaphore_Translate_core_mutex_return_code + * + * Input parameters: + * the_mutex_status - mutex status code to translate + * + * Output parameters: + * rtems status code - translated RTEMS status code + * + */ + +rtems_status_code _Semaphore_Translate_core_mutex_return_code ( + unsigned32 the_mutex_status +) +{ + switch ( the_mutex_status ) { + case CORE_MUTEX_STATUS_SUCCESSFUL: + return RTEMS_SUCCESSFUL; + case CORE_MUTEX_STATUS_UNSATISFIED_NOWAIT: + return RTEMS_UNSATISFIED; + case CORE_MUTEX_STATUS_NESTING_NOT_ALLOWED: + return RTEMS_INTERNAL_ERROR; + case CORE_MUTEX_STATUS_NOT_OWNER_OF_RESOURCE: + return RTEMS_NOT_OWNER_OF_RESOURCE; + case CORE_MUTEX_WAS_DELETED: + return RTEMS_OBJECT_WAS_DELETED; + case CORE_MUTEX_TIMEOUT: + return RTEMS_TIMEOUT; + case THREAD_STATUS_PROXY_BLOCKING: + return THREAD_STATUS_PROXY_BLOCKING; + } + return RTEMS_INTERNAL_ERROR; /* unreached - only to remove warnings */ +} + +/*PAGE + * + * _Semaphore_Translate_core_semaphore_return_code + * + * Input parameters: + * the_semaphore_status - semaphore status code to translate + * + * Output parameters: + * rtems status code - translated RTEMS status code + * + */ + +rtems_status_code _Semaphore_Translate_core_semaphore_return_code ( + unsigned32 the_semaphore_status +) +{ + switch ( the_semaphore_status ) { + case CORE_SEMAPHORE_STATUS_SUCCESSFUL: + return RTEMS_SUCCESSFUL; + case CORE_SEMAPHORE_STATUS_UNSATISFIED_NOWAIT: + return RTEMS_UNSATISFIED; + case CORE_SEMAPHORE_WAS_DELETED: + return RTEMS_OBJECT_WAS_DELETED; + case CORE_SEMAPHORE_TIMEOUT: + return RTEMS_TIMEOUT; + case THREAD_STATUS_PROXY_BLOCKING: + return THREAD_STATUS_PROXY_BLOCKING; + } + return RTEMS_INTERNAL_ERROR; /* unreached - only to remove warnings */ +} + +/*PAGE + * + * _Semaphore_Core_mutex_mp_support + * + * Input parameters: + * the_thread - the remote thread the semaphore was surrendered to + * id - id of the surrendered semaphore + * + * Output parameters: NONE + */ + +void _Semaphore_Core_mutex_mp_support ( + Thread_Control *the_thread, + Objects_Id id +) +{ + the_thread->receive_packet->return_code = RTEMS_SUCCESSFUL; + + _Semaphore_MP_Send_response_packet( + SEMAPHORE_MP_OBTAIN_RESPONSE, + id, + the_thread + ); +} + + +/*PAGE + * + * _Semaphore_Core_semaphore_mp_support + * + * Input parameters: + * the_thread - the remote thread the semaphore was surrendered to + * id - id of the surrendered semaphore + * + * Output parameters: NONE + */ + +void _Semaphore_Core_semaphore_mp_support ( + Thread_Control *the_thread, + Objects_Id id +) +{ + the_thread->receive_packet->return_code = RTEMS_SUCCESSFUL; + + _Semaphore_MP_Send_response_packet( + SEMAPHORE_MP_OBTAIN_RESPONSE, + id, + the_thread + ); +} |