/*
* 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 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>
#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
);
}