/*
* Event Manager
*
* 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/event.h>
#include <rtems/score/isr.h>
#include <rtems/score/object.h>
#include <rtems/rtems/options.h>
#include <rtems/score/states.h>
#include <rtems/score/thread.h>
#include <rtems/rtems/tasks.h>
/*PAGE
*
* _Event_Manager_initialization
*
* DESCRIPTION:
*
* This routine performs the initialization necessary for this manager.
*/
void _Event_Manager_initialization( void )
{
_Event_Sync_state = EVENT_SYNC_SYNCHRONIZED;
/*
* Register the MP Process Packet routine.
*/
_MPCI_Register_packet_processor( MP_PACKET_EVENT, _Event_MP_Process_packet );
}
/*PAGE
*
* rtems_event_send
*
* This directive allows a thread send an event set to another thread.
*
* Input parameters:
* id - thread id
* event - event set
*
* Output parameters:
* RTEMS_SUCCESSFUL - if successful
* error code - if unsuccessful
*/
rtems_status_code rtems_event_send(
Objects_Id id,
rtems_event_set event_in
)
{
register Thread_Control *the_thread;
Objects_Locations location;
RTEMS_API_Control *api;
the_thread = _Thread_Get( id, &location );
switch ( location ) {
case OBJECTS_ERROR:
return RTEMS_INVALID_ID;
case OBJECTS_REMOTE:
return(
_Event_MP_Send_request_packet(
EVENT_MP_SEND_REQUEST,
id,
event_in
)
);
case OBJECTS_LOCAL:
api = the_thread->API_Extensions[ THREAD_API_RTEMS ];
_Event_sets_Post( event_in, &api->pending_events );
_Event_Surrender( the_thread );
_Thread_Enable_dispatch();
return RTEMS_SUCCESSFUL;
}
return RTEMS_INTERNAL_ERROR; /* unreached - only to remove warnings */
}
/*PAGE
*
* rtems_event_receive
*
* This directive allows a thread to receive a set of events.
*
* Input parameters:
* event_in - input event condition
* option_set - options
* ticks - number of ticks to wait (0 means wait forever)
* event_out - pointer to output event set
*
* Output parameters:
* event out - event set
* RTEMS_SUCCESSFUL - if successful
* error code - if unsuccessful
*/
rtems_status_code rtems_event_receive(
rtems_event_set event_in,
rtems_option option_set,
rtems_interval ticks,
rtems_event_set *event_out
)
{
RTEMS_API_Control *api;
api = _Thread_Executing->API_Extensions[ THREAD_API_RTEMS ];
if ( _Event_sets_Is_empty( event_in ) ) {
*event_out = api->pending_events;
return RTEMS_SUCCESSFUL;
}
_Thread_Disable_dispatch();
_Event_Seize( event_in, option_set, ticks, event_out );
_Thread_Enable_dispatch();
return( _Thread_Executing->Wait.return_code );
}
/*PAGE
*
* _Event_Seize
*
* This routine attempts to satisfy the requested event condition
* for the running thread.
*
* Input parameters:
* event_in - the event condition to satisfy
* option_set - acquire event options
* ticks - interval to wait
* event_out - pointer to event set output area
*
* Output parameters: NONE
* *event_out - event set output area filled in
*
* INTERRUPT LATENCY:
* available
* wait
* check sync
*/
void _Event_Seize(
rtems_event_set event_in,
rtems_option option_set,
rtems_interval ticks,
rtems_event_set *event_out
)
{
Thread_Control *executing;
rtems_event_set seized_events;
rtems_event_set pending_events;
ISR_Level level;
RTEMS_API_Control *api;
Event_Sync_states sync_state;
executing = _Thread_Executing;
executing->Wait.return_code = RTEMS_SUCCESSFUL;
api = executing->API_Extensions[ THREAD_API_RTEMS ];
_ISR_Disable( level );
pending_events = api->pending_events;
seized_events = _Event_sets_Get( pending_events, event_in );
if ( !_Event_sets_Is_empty( seized_events ) &&
(seized_events == event_in || _Options_Is_any( option_set )) ) {
api->pending_events =
_Event_sets_Clear( pending_events, seized_events );
_ISR_Enable( level );
*event_out = seized_events;
return;
}
if ( _Options_Is_no_wait( option_set ) ) {
_ISR_Enable( level );
executing->Wait.return_code = RTEMS_UNSATISFIED;
*event_out = seized_events;
return;
}
_Event_Sync_state = EVENT_SYNC_NOTHING_HAPPENED;
executing->Wait.option = (unsigned32) option_set;
executing->Wait.count = (unsigned32) event_in;
executing->Wait.return_argument = event_out;
_ISR_Enable( level );
if ( ticks ) {
_Watchdog_Initialize(
&executing->Timer,
_Event_Timeout,
executing->Object.id,
NULL
);
_Watchdog_Insert_ticks( &executing->Timer, ticks );
}
_Thread_Set_state( executing, STATES_WAITING_FOR_EVENT );
_ISR_Disable( level );
sync_state = _Event_Sync_state;
_Event_Sync_state = EVENT_SYNC_SYNCHRONIZED;
switch ( sync_state ) {
case EVENT_SYNC_SYNCHRONIZED:
/*
* This cannot happen. It indicates that this routine did not
* enter the synchronization states above.
*/
return;
case EVENT_SYNC_NOTHING_HAPPENED:
_ISR_Enable( level );
return;
case EVENT_SYNC_TIMEOUT:
executing->Wait.return_code = RTEMS_TIMEOUT;
_ISR_Enable( level );
_Thread_Unblock( executing );
return;
case EVENT_SYNC_SATISFIED:
if ( _Watchdog_Is_active( &executing->Timer ) ) {
_Watchdog_Deactivate( &executing->Timer );
_ISR_Enable( level );
(void) _Watchdog_Remove( &executing->Timer );
} else
_ISR_Enable( level );
_Thread_Unblock( executing );
return;
}
}
/*PAGE
*
* _Event_Surrender
*
* This routines remove a thread from the specified threadq.
*
* Input parameters:
* the_thread - pointer to thread to be dequeued
*
* Output parameters: NONE
*
* INTERRUPT LATENCY:
* before flash
* after flash
* check sync
*/
void _Event_Surrender(
Thread_Control *the_thread
)
{
ISR_Level level;
rtems_event_set pending_events;
rtems_event_set event_condition;
rtems_event_set seized_events;
rtems_option option_set;
RTEMS_API_Control *api;
api = the_thread->API_Extensions[ THREAD_API_RTEMS ];
option_set = (rtems_option) the_thread->Wait.option;
_ISR_Disable( level );
pending_events = api->pending_events;
event_condition = (rtems_event_set) the_thread->Wait.count;
seized_events = _Event_sets_Get( pending_events, event_condition );
if ( !_Event_sets_Is_empty( seized_events ) ) {
if ( _States_Is_waiting_for_event( the_thread->current_state ) ) {
if ( seized_events == event_condition || _Options_Is_any( option_set ) ) {
api->pending_events =
_Event_sets_Clear( pending_events, seized_events );
*(rtems_event_set *)the_thread->Wait.return_argument = seized_events;
_ISR_Flash( level );
if ( !_Watchdog_Is_active( &the_thread->Timer ) ) {
_ISR_Enable( level );
_Thread_Unblock( the_thread );
}
else {
_Watchdog_Deactivate( &the_thread->Timer );
_ISR_Enable( level );
(void) _Watchdog_Remove( &the_thread->Timer );
_Thread_Unblock( the_thread );
}
return;
}
}
switch ( _Event_Sync_state ) {
case EVENT_SYNC_SYNCHRONIZED:
case EVENT_SYNC_SATISFIED:
break;
case EVENT_SYNC_NOTHING_HAPPENED:
case EVENT_SYNC_TIMEOUT:
if ( !_Thread_Is_executing( the_thread ) )
break;
if ( seized_events == event_condition || _Options_Is_any(option_set) ) {
api->pending_events =
_Event_sets_Clear( pending_events,seized_events );
*(rtems_event_set *)the_thread->Wait.return_argument = seized_events;
_Event_Sync_state = EVENT_SYNC_SATISFIED;
}
break;
}
}
_ISR_Enable( level );
}
/*PAGE
*
* _Event_Timeout
*
* This routine processes a thread which timeouts while waiting to
* receive an event_set. It is called by the watchdog handler.
*
* Input parameters:
* id - thread id
*
* Output parameters: NONE
*/
void _Event_Timeout(
Objects_Id id,
void *ignored
)
{
Thread_Control *the_thread;
Objects_Locations location;
the_thread = _Thread_Get( id, &location );
switch ( location ) {
case OBJECTS_ERROR:
case OBJECTS_REMOTE: /* impossible */
break;
case OBJECTS_LOCAL:
/*
* If the event manager is not synchronized, then it is either
* "nothing happened", "timeout", or "satisfied". If the_thread
* is the executing thread, then it is in the process of blocking
* and it is the thread which is responsible for the synchronization
* process.
*
* If it is not satisfied, then it is "nothing happened" and
* this is the "timeout" transition. After a request is satisfied,
* a timeout is not allowed to occur.
*/
if ( _Event_Sync_state != EVENT_SYNC_SYNCHRONIZED &&
_Thread_Is_executing( the_thread ) ) {
if ( _Event_Sync_state != EVENT_SYNC_SATISFIED )
_Event_Sync_state = EVENT_SYNC_TIMEOUT;
} else {
the_thread->Wait.return_code = RTEMS_TIMEOUT;
_Thread_Unblock( the_thread );
}
_Thread_Unnest_dispatch();
break;
}
}