/*
* Rate Monotonic Manager
*
*
* 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.
*
* $Id$
*/
#include <rtems/system.h>
#include <rtems/isr.h>
#include <rtems/object.h>
#include <rtems/ratemon.h>
#include <rtems/thread.h>
/*PAGE
*
* _Rate_monotonic_Manager_initialization
*
* This routine initializes all Rate Monotonic Manager related
* data structures.
*
* Input parameters:
* maximum_periods - number of periods timers to initialize
*
* Output parameters: NONE
*
* NOTE: The Rate Monotonic Manager is built on top of the Watchdog
* Handler.
*/
void _Rate_monotonic_Manager_initialization(
unsigned32 maximum_periods
)
{
_Objects_Initialize_information(
&_Rate_monotonic_Information,
FALSE,
maximum_periods,
sizeof( Rate_monotonic_Control )
);
}
/*PAGE
*
* rtems_rate_monotonic_create
*
* This directive creates a rate monotonic timer and performs
* some initialization.
*
* Input parameters:
* name - name of period
* id - pointer to rate monotonic id
*
* Output parameters:
* id - rate monotonic id
* RTEMS_SUCCESSFUL - if successful
* error code - if unsuccessful
*/
rtems_status_code rtems_rate_monotonic_create(
Objects_Name name,
Objects_Id *id
)
{
Rate_monotonic_Control *the_period;
if ( !_Objects_Is_name_valid( name ) )
return( RTEMS_INVALID_NAME );
_Thread_Disable_dispatch(); /* to prevent deletion */
the_period = _Rate_monotonic_Allocate();
if ( !the_period ) {
_Thread_Enable_dispatch();
return( RTEMS_TOO_MANY );
}
the_period->owner = _Thread_Executing;
the_period->state = RATE_MONOTONIC_INACTIVE;
_Objects_Open( &_Rate_monotonic_Information, &the_period->Object, name );
*id = the_period->Object.id;
_Thread_Enable_dispatch();
return( RTEMS_SUCCESSFUL );
}
/*PAGE
*
* rtems_rate_monotonic_ident
*
* This directive returns the system ID associated with
* the rate monotonic period name.
*
* Input parameters:
* name - user defined period name
* id - pointer to period id
*
* Output parameters:
* *id - region id
* RTEMS_SUCCESSFUL - if successful
* error code - if unsuccessful
*/
rtems_status_code rtems_rate_monotonic_ident(
Objects_Name name,
Objects_Id *id
)
{
return _Objects_Name_to_id(
&_Rate_monotonic_Information,
name,
RTEMS_SEARCH_LOCAL_NODE,
id
);
}
/*PAGE
*
* rtems_rate_monotonic_cancel
*
* This directive allows a thread to cancel a rate monotonic timer.
*
* Input parameters:
* id - rate monotonic id
*
* Output parameters:
* RTEMS_SUCCESSFUL - if successful and caller is not the owning thread
* error code - if unsuccessful
*/
rtems_status_code rtems_rate_monotonic_cancel(
Objects_Id id
)
{
Rate_monotonic_Control *the_period;
Objects_Locations location;
the_period = _Rate_monotonic_Get( id, &location );
switch ( location ) {
case OBJECTS_ERROR:
return( RTEMS_INVALID_ID );
case OBJECTS_REMOTE: /* should never return this */
return( RTEMS_INTERNAL_ERROR );
case OBJECTS_LOCAL:
if ( !_Thread_Is_executing( the_period->owner ) ) {
_Thread_Enable_dispatch();
return( RTEMS_NOT_OWNER_OF_RESOURCE );
}
(void) _Watchdog_Remove( &the_period->Timer );
the_period->state = RATE_MONOTONIC_INACTIVE;
_Thread_Enable_dispatch();
return( RTEMS_SUCCESSFUL );
}
return( RTEMS_INTERNAL_ERROR ); /* unreached - only to remove warnings */
}
/*PAGE
*
* rtems_rate_monotonic_delete
*
* This directive allows a thread to delete a rate monotonic timer.
*
* Input parameters:
* id - rate monotonic id
*
* Output parameters:
* RTEMS_SUCCESSFUL - if successful
* error code - if unsuccessful
*/
rtems_status_code rtems_rate_monotonic_delete(
Objects_Id id
)
{
Rate_monotonic_Control *the_period;
Objects_Locations location;
the_period = _Rate_monotonic_Get( id, &location );
switch ( location ) {
case OBJECTS_ERROR:
return( RTEMS_INVALID_ID );
case OBJECTS_REMOTE: /* should never return this */
return( RTEMS_INTERNAL_ERROR );
case OBJECTS_LOCAL:
_Objects_Close( &_Rate_monotonic_Information, &the_period->Object );
(void) _Watchdog_Remove( &the_period->Timer );
the_period->state = RATE_MONOTONIC_INACTIVE;
_Rate_monotonic_Free( the_period );
_Thread_Enable_dispatch();
return( RTEMS_SUCCESSFUL );
}
return( RTEMS_INTERNAL_ERROR ); /* unreached - only to remove warnings */
}
/*PAGE
*
* rtems_rate_monotonic_period
*
* This directive allows a thread to manipulate a rate monotonic timer.
*
* Input parameters:
* id - rate monotonic id
* length - length of period (in ticks)
*
* Output parameters:
* RTEMS_SUCCESSFUL - if successful
* error code - if unsuccessful
*/
rtems_status_code rtems_rate_monotonic_period(
Objects_Id id,
rtems_interval length
)
{
Rate_monotonic_Control *the_period;
Objects_Locations location;
rtems_status_code return_value;
the_period = _Rate_monotonic_Get( id, &location );
switch ( location ) {
case OBJECTS_ERROR:
return( RTEMS_INVALID_ID );
case OBJECTS_REMOTE: /* should never return this */
return( RTEMS_INTERNAL_ERROR );
case OBJECTS_LOCAL:
if ( !_Thread_Is_executing( the_period->owner ) ) {
_Thread_Enable_dispatch();
return( RTEMS_NOT_OWNER_OF_RESOURCE );
}
if ( length == RTEMS_PERIOD_STATUS ) {
switch ( the_period->state ) {
case RATE_MONOTONIC_INACTIVE:
return_value = RTEMS_NOT_DEFINED;
break;
case RATE_MONOTONIC_ACTIVE:
return_value = RTEMS_SUCCESSFUL;
break;
case RATE_MONOTONIC_EXPIRED:
return_value = RTEMS_TIMEOUT;
break;
default: /* unreached -- only to remove warnings */
return_value = RTEMS_INTERNAL_ERROR;
break;
}
_Thread_Enable_dispatch();
return( return_value );
}
switch ( the_period->state ) {
case RATE_MONOTONIC_INACTIVE:
the_period->state = RATE_MONOTONIC_ACTIVE;
_Watchdog_Initialize(
&the_period->Timer,
_Rate_monotonic_Timeout,
id,
NULL
);
_Watchdog_Insert_ticks(
&the_period->Timer, length, WATCHDOG_ACTIVATE_NOW );
_Thread_Enable_dispatch();
return( RTEMS_SUCCESSFUL );
case RATE_MONOTONIC_ACTIVE:
/* following is and could be a critical section problem */
_Thread_Executing->Wait.id = the_period->Object.id;
if ( _Rate_monotonic_Set_state( the_period ) ) {
_Thread_Enable_dispatch();
return( RTEMS_SUCCESSFUL );
}
/* has expired -- fall into next case */
case RATE_MONOTONIC_EXPIRED:
the_period->state = RATE_MONOTONIC_ACTIVE;
_Watchdog_Insert_ticks(
&the_period->Timer, length, WATCHDOG_ACTIVATE_NOW );
_Thread_Enable_dispatch();
return( RTEMS_TIMEOUT );
}
}
return( RTEMS_INTERNAL_ERROR ); /* unreached - only to remove warnings */
}
/*PAGE
*
* _Rate_monotonic_Set_state
*
* This kernel routine sets the STATES_WAITING_FOR_PERIOD state in
* the running thread's tcb if the specified period has not expired.
* The ready chain is adjusted if necessary.
*
* Input parameters:
* the_period - pointer to period control block
*
* Output parameters:
* TRUE - if blocked successfully for period
* FALSE - if period has expired
*
* INTERRUPT LATENCY:
* delete node
* priority map
* select heir
*/
boolean _Rate_monotonic_Set_state(
Rate_monotonic_Control *the_period
)
{
Thread_Control *executing;
Chain_Control *ready;
ISR_Level level;
States_Control old_state;
executing = _Thread_Executing;
ready = executing->ready;
_ISR_Disable( level );
old_state = executing->current_state;
if ( _Rate_monotonic_Is_expired( the_period ) ) {
_ISR_Enable( level );
return( FALSE );
}
executing->current_state =
_States_Set( STATES_WAITING_FOR_PERIOD, old_state );
if ( _States_Is_ready( old_state ) ) {
if ( _Chain_Has_only_one_node( ready ) ) {
_Chain_Initialize_empty( ready );
_Priority_Remove_from_bit_map( &executing->Priority_map );
_ISR_Flash( level );
} else {
_Chain_Extract_unprotected( &executing->Object.Node );
_ISR_Flash( level );
}
if ( _Thread_Is_heir( executing ) )
_Thread_Calculate_heir();
_Context_Switch_necessary = TRUE;
}
_ISR_Enable( level );
return( TRUE );
}
/*PAGE
*
* _Rate_monotonic_Timeout
*
* This routine processes a period ending. If the owning thread
* is waiting for the period, that thread is unblocked and the
* period reinitiated. Otherwise, the period is expired.
* This routine is called by the watchdog handler.
*
* Input parameters:
* id - period id
*
* Output parameters: NONE
*/
void _Rate_monotonic_Timeout(
Objects_Id id,
void *ignored
)
{
Rate_monotonic_Control *the_period;
Objects_Locations location;
Thread_Control *the_thread;
the_period = _Rate_monotonic_Get( id, &location );
switch ( location ) {
case OBJECTS_ERROR:
case OBJECTS_REMOTE: /* impossible */
break;
case OBJECTS_LOCAL:
the_thread = the_period->owner;
if ( _States_Is_waiting_for_period( the_thread->current_state ) &&
the_thread->Wait.id == the_period->Object.id ) {
_Thread_Unblock( the_thread );
_Watchdog_Reset( &the_period->Timer );
}
else
the_period->state = RATE_MONOTONIC_EXPIRED;
_Thread_Unnest_dispatch();
break;
}
}
