/**
* @brief rtems_timer_initiate_server
*
* This directive creates and starts the server for task-based timers.
* It must be invoked before any task-based timers can be initiated.
*
* @param[in] priority is the timer server priority
* @param[in] stack_size is the stack size in bytes
* @param[in] attribute_set is the timer server attributes
*
* @return This method returns RTEMS_SUCCESSFUL if successful and an
* error code otherwise.
*/
rtems_status_code rtems_timer_initiate_server(
uint32_t priority,
uint32_t stack_size,
rtems_attribute attribute_set
)
{
rtems_id id;
rtems_status_code status;
rtems_task_priority _priority;
static bool initialized = false;
bool tmpInitialized;
Timer_server_Control *ts = &_Timer_server_Default;
/*
* Make sure the requested priority is valid. The if is
* structured so we check it is invalid before looking for
* a specific invalid value as the default.
*/
_priority = priority;
if ( !_RTEMS_tasks_Priority_is_valid( priority ) ) {
if ( priority != RTEMS_TIMER_SERVER_DEFAULT_PRIORITY )
return RTEMS_INVALID_PRIORITY;
_priority = 0;
}
/*
* Just to make sure this is only called once.
*/
_Thread_Disable_dispatch();
tmpInitialized = initialized;
initialized = true;
_Thread_Enable_dispatch();
if ( tmpInitialized )
return RTEMS_INCORRECT_STATE;
/*
* Create the Timer Server with the name the name of "TIME". The attribute
* RTEMS_SYSTEM_TASK allows us to set a priority to 0 which will makes it
* higher than any other task in the system. It can be viewed as a low
* priority interrupt. It is also always NO_PREEMPT so it looks like
* an interrupt to other tasks.
*
* We allow the user to override the default priority because the Timer
* Server can invoke TSRs which must adhere to language run-time or
* other library rules. For example, if using a TSR written in Ada the
* Server should run at the same priority as the priority Ada task.
* Otherwise, the priority ceiling for the mutex used to protect the
* GNAT run-time is violated.
*/
status = rtems_task_create(
_Objects_Build_name('T','I','M','E'), /* "TIME" */
_priority, /* create with priority 1 since 0 is illegal */
stack_size, /* let user specify stack size */
RTEMS_NO_PREEMPT, /* no preempt is like an interrupt */
/* user may want floating point but we need */
/* system task specified for 0 priority */
attribute_set | RTEMS_SYSTEM_TASK,
&id /* get the id back */
);
if (status) {
initialized = false;
return status;
}
/*
* Do all the data structure initialization before starting the
* Timer Server so we do not have to have a critical section.
*/
/*
* We work with the TCB pointer, not the ID, so we need to convert
* to a TCB pointer from here out.
*/
ts->thread = (Thread_Control *)_Objects_Get_local_object(
&_RTEMS_tasks_Information,
_Objects_Get_index(id)
);
/*
* Initialize the timer lists that the server will manage.
*/
_Chain_Initialize_empty( &ts->Interval_watchdogs.Chain );
_Chain_Initialize_empty( &ts->TOD_watchdogs.Chain );
/*
* Initialize the timers that will be used to control when the
* Timer Server wakes up and services the task-based timers.
*/
_Watchdog_Initialize(
&ts->Interval_watchdogs.System_watchdog,
_Thread_Delay_ended,
id,
NULL
);
_Watchdog_Initialize(
&ts->TOD_watchdogs.System_watchdog,
_Thread_Delay_ended,
id,
NULL
);
/*
* Initialize the pointer to the timer schedule method so applications that
* do not use the Timer Server do not have to pull it in.
*/
ts->schedule_operation = _Timer_server_Schedule_operation_method;
ts->Interval_watchdogs.last_snapshot = _Watchdog_Ticks_since_boot;
ts->TOD_watchdogs.last_snapshot = (Watchdog_Interval) _TOD_Seconds_since_epoch();
ts->insert_chain = NULL;
ts->active = false;
/*
* The default timer server is now available.
*/
_Timer_server = ts;
/*
* Start the timer server
*/
status = rtems_task_start(
id,
_Timer_server_Body,
(rtems_task_argument) ts
);
#if defined(RTEMS_DEBUG)
/*
* One would expect a call to rtems_task_delete() here to clean up
* but there is actually no way (in normal circumstances) that the
* start can fail. The id and starting address are known to be
* be good. If this service fails, something is weirdly wrong on the
* target such as a stray write in an ISR or incorrect memory layout.
*/
if (status) {
initialized = false;
}
#endif
return status;
}
int rtems_object_id_get_index(
rtems_id id
)
{
return _Objects_Get_index( id );
}
void _Objects_Extend_information(
Objects_Information *information
)
{
Objects_Control *the_object;
Chain_Control Inactive;
uint32_t block_count;
uint32_t block;
uint32_t index_base;
uint32_t minimum_index;
uint32_t index;
uint32_t maximum;
size_t block_size;
void *new_object_block;
bool do_extend;
/*
* Search for a free block of indexes. If we do NOT need to allocate or
* extend the block table, then we will change do_extend.
*/
do_extend = true;
minimum_index = _Objects_Get_index( information->minimum_id );
index_base = minimum_index;
block = 0;
/* if ( information->maximum < minimum_index ) */
if ( information->object_blocks == NULL )
block_count = 0;
else {
block_count = information->maximum / information->allocation_size;
for ( ; block < block_count; block++ ) {
if ( information->object_blocks[ block ] == NULL ) {
do_extend = false;
break;
} else
index_base += information->allocation_size;
}
}
maximum = (uint32_t) information->maximum + information->allocation_size;
/*
* We need to limit the number of objects to the maximum number
* representable in the index portion of the object Id. In the
* case of 16-bit Ids, this is only 256 object instances.
*/
if ( maximum > OBJECTS_ID_FINAL_INDEX ) {
return;
}
/*
* Allocate the name table, and the objects and if it fails either return or
* generate a fatal error depending on auto-extending being active.
*/
block_size = information->allocation_size * information->size;
if ( information->auto_extend ) {
new_object_block = _Workspace_Allocate( block_size );
if ( !new_object_block )
return;
} else {
new_object_block = _Workspace_Allocate_or_fatal_error( block_size );
}
/*
* Do we need to grow the tables?
*/
if ( do_extend ) {
ISR_Level level;
void **object_blocks;
uint32_t *inactive_per_block;
Objects_Control **local_table;
void *old_tables;
size_t block_size;
/*
* Growing the tables means allocating a new area, doing a copy and
* updating the information table.
*
* If the maximum is minimum we do not have a table to copy. First
* time through.
*
* The allocation has :
*
* void *objects[block_count];
* uint32_t inactive_count[block_count];
* Objects_Control *local_table[maximum];
*
* This is the order in memory. Watch changing the order. See the memcpy
* below.
*/
/*
* Up the block count and maximum
*/
block_count++;
/*
* Allocate the tables and break it up.
*/
block_size = block_count *
(sizeof(void *) + sizeof(uint32_t) + sizeof(Objects_Name *)) +
((maximum + minimum_index) * sizeof(Objects_Control *));
object_blocks = (void**) _Workspace_Allocate( block_size );
if ( !object_blocks ) {
_Workspace_Free( new_object_block );
return;
}
/*
* Break the block into the various sections.
*/
inactive_per_block = (uint32_t *) _Addresses_Add_offset(
object_blocks, block_count * sizeof(void*) );
local_table = (Objects_Control **) _Addresses_Add_offset(
inactive_per_block, block_count * sizeof(uint32_t) );
/*
* Take the block count down. Saves all the (block_count - 1)
* in the copies.
*/
block_count--;
if ( information->maximum > minimum_index ) {
/*
* Copy each section of the table over. This has to be performed as
* separate parts as size of each block has changed.
*/
memcpy( object_blocks,
information->object_blocks,
block_count * sizeof(void*) );
memcpy( inactive_per_block,
information->inactive_per_block,
block_count * sizeof(uint32_t) );
memcpy( local_table,
information->local_table,
(information->maximum + minimum_index) * sizeof(Objects_Control *) );
} else {
/*
* Deal with the special case of the 0 to minimum_index
*/
for ( index = 0; index < minimum_index; index++ ) {
local_table[ index ] = NULL;
}
}
/*
* Initialise the new entries in the table.
*/
object_blocks[block_count] = NULL;
inactive_per_block[block_count] = 0;
for ( index=index_base ;
index < ( information->allocation_size + index_base );
index++ ) {
local_table[ index ] = NULL;
}
_ISR_Disable( level );
old_tables = information->object_blocks;
information->object_blocks = object_blocks;
information->inactive_per_block = inactive_per_block;
information->local_table = local_table;
information->maximum = (Objects_Maximum) maximum;
information->maximum_id = _Objects_Build_id(
information->the_api,
information->the_class,
_Objects_Local_node,
information->maximum
);
_ISR_Enable( level );
_Workspace_Free( old_tables );
block_count++;
}
/*
* Assign the new object block to the object block table.
*/
information->object_blocks[ block ] = new_object_block;
/*
* Initialize objects .. add to a local chain first.
*/
_Chain_Initialize(
&Inactive,
information->object_blocks[ block ],
information->allocation_size,
information->size
);
/*
* Move from the local chain, initialise, then append to the inactive chain
*/
index = index_base;
while ((the_object = (Objects_Control *) _Chain_Get( &Inactive )) != NULL ) {
the_object->id = _Objects_Build_id(
information->the_api,
information->the_class,
_Objects_Local_node,
index
);
_Chain_Append( &information->Inactive, &the_object->Node );
index++;
}
information->inactive_per_block[ block ] = information->allocation_size;
information->inactive =
(Objects_Maximum)(information->inactive + information->allocation_size);
}
