States_Control _Thread_Set_state(
Thread_Control *the_thread,
States_Control state
)
{
ISR_lock_Context lock_context;
States_Control previous_state;
States_Control next_state;
_Assert( state != 0 );
_Thread_State_acquire( the_thread, &lock_context );
previous_state = the_thread->current_state;
next_state = _States_Set( state, previous_state);
the_thread->current_state = next_state;
if ( _States_Is_ready( previous_state ) ) {
_Scheduler_Block( the_thread );
}
_Thread_State_release( the_thread, &lock_context );
return previous_state;
}
void _Thread_Set_transient(
Thread_Control *the_thread
)
{
ISR_Level level;
uint32_t old_state;
Chain_Control *ready;
ready = the_thread->ready;
_ISR_Disable( level );
old_state = the_thread->current_state;
the_thread->current_state = _States_Set( STATES_TRANSIENT, old_state );
if ( _States_Is_ready( old_state ) ) {
if ( _Chain_Has_only_one_node( ready ) ) {
_Chain_Initialize_empty( ready );
_Priority_Remove_from_bit_map( &the_thread->Priority_map );
} else
_Chain_Extract_unprotected( &the_thread->Object.Node );
}
_ISR_Enable( level );
}
void _Scheduler_priority_Tick( void )
{
Thread_Control *executing;
executing = _Thread_Executing;
#ifdef __RTEMS_USE_TICKS_FOR_STATISTICS__
/*
* Increment the number of ticks this thread has been executing
*/
executing->cpu_time_used++;
#endif
/*
* If the thread is not preemptible or is not ready, then
* just return.
*/
if ( !executing->is_preemptible )
return;
if ( !_States_Is_ready( executing->current_state ) )
return;
/*
* The cpu budget algorithm determines what happens next.
*/
switch ( executing->budget_algorithm ) {
case THREAD_CPU_BUDGET_ALGORITHM_NONE:
break;
case THREAD_CPU_BUDGET_ALGORITHM_RESET_TIMESLICE:
#if defined(RTEMS_SCORE_THREAD_ENABLE_EXHAUST_TIMESLICE)
case THREAD_CPU_BUDGET_ALGORITHM_EXHAUST_TIMESLICE:
#endif
if ( (int)(--executing->cpu_time_budget) <= 0 ) {
/*
* A yield performs the ready chain mechanics needed when
* resetting a timeslice. If no other thread's are ready
* at the priority of the currently executing thread, then the
* executing thread's timeslice is reset. Otherwise, the
* currently executing thread is placed at the rear of the
* FIFO for this priority and a new heir is selected.
*/
_Scheduler_Yield();
executing->cpu_time_budget = _Thread_Ticks_per_timeslice;
}
break;
#if defined(RTEMS_SCORE_THREAD_ENABLE_SCHEDULER_CALLOUT)
case THREAD_CPU_BUDGET_ALGORITHM_CALLOUT:
if ( --executing->cpu_time_budget == 0 )
(*executing->budget_callout)( executing );
break;
#endif
}
}
bool _Scheduler_priority_affinity_SMP_Set_affinity(
const Scheduler_Control *scheduler,
Thread_Control *thread,
size_t cpusetsize,
const cpu_set_t *cpuset
)
{
Scheduler_priority_affinity_SMP_Node *node;
States_Control current_state;
/*
* Validate that the cpset meets basic requirements.
*/
if ( !_CPU_set_Is_valid( cpuset, cpusetsize ) ) {
return false;
}
node = _Scheduler_priority_affinity_SMP_Thread_get_node( thread );
/*
* The old and new set are the same, there is no point in
* doing anything.
*/
if ( CPU_EQUAL_S( cpusetsize, cpuset, node->Affinity.set ) )
return true;
current_state = thread->current_state;
if ( _States_Is_ready( current_state ) ) {
_Scheduler_priority_affinity_SMP_Block( scheduler, thread );
}
CPU_COPY( node->Affinity.set, cpuset );
if ( _States_Is_ready( current_state ) ) {
/*
* FIXME: Do not ignore threads in need for help.
*/
(void) _Scheduler_priority_affinity_SMP_Unblock( scheduler, thread );
}
return true;
}
void _Thread_Tickle_timeslice( void )
{
Thread_Control *executing;
executing = _Thread_Executing;
#ifdef __RTEMS_USE_TICKS_FOR_STATISTICS__
/*
* Increment the number of ticks this thread has been executing
*/
executing->cpu_time_used++;
#endif
/*
* If the thread is not preemptible or is not ready, then
* just return.
*/
if ( !executing->is_preemptible )
return;
if ( !_States_Is_ready( executing->current_state ) )
return;
/*
* The cpu budget algorithm determines what happens next.
*/
switch ( executing->budget_algorithm ) {
case THREAD_CPU_BUDGET_ALGORITHM_NONE:
break;
case THREAD_CPU_BUDGET_ALGORITHM_RESET_TIMESLICE:
#if defined(RTEMS_SCORE_THREAD_ENABLE_EXHAUST_TIMESLICE)
case THREAD_CPU_BUDGET_ALGORITHM_EXHAUST_TIMESLICE:
#endif
if ( (int)(--executing->cpu_time_budget) <= 0 ) {
_Thread_Reset_timeslice();
executing->cpu_time_budget = _Thread_Ticks_per_timeslice;
}
break;
#if defined(RTEMS_SCORE_THREAD_ENABLE_SCHEDULER_CALLOUT)
case THREAD_CPU_BUDGET_ALGORITHM_CALLOUT:
if ( --executing->cpu_time_budget == 0 )
(*executing->budget_callout)( executing );
break;
#endif
}
}
bool _Thread_Evaluate_mode( void )
{
Thread_Control *executing;
executing = _Thread_Executing;
if ( !_States_Is_ready( executing->current_state ) ||
( !_Thread_Is_heir( executing ) && executing->is_preemptible ) ) {
_Context_Switch_necessary = true;
return true;
}
return false;
}
void _Thread_Resume(
Thread_Control *the_thread,
bool force
)
{
ISR_Level level;
States_Control current_state;
_ISR_Disable( level );
#if defined(RTEMS_ITRON_API)
if ( force == true )
the_thread->suspend_count = 0;
else
the_thread->suspend_count--;
if ( the_thread->suspend_count > 0 ) {
_ISR_Enable( level );
return;
}
#endif
current_state = the_thread->current_state;
if ( current_state & STATES_SUSPENDED ) {
current_state =
the_thread->current_state = _States_Clear(STATES_SUSPENDED, current_state);
if ( _States_Is_ready( current_state ) ) {
_Priority_Add_to_bit_map( &the_thread->Priority_map );
_Chain_Append_unprotected(the_thread->ready, &the_thread->Object.Node);
_ISR_Flash( level );
if ( the_thread->current_priority < _Thread_Heir->current_priority ) {
_Thread_Heir = the_thread;
if ( _Thread_Executing->is_preemptible ||
the_thread->current_priority == 0 )
_Context_Switch_necessary = true;
}
}
}
_ISR_Enable( level );
}
void _Thread_Clear_state(
Thread_Control *the_thread,
States_Control state
)
{
ISR_Level level;
States_Control current_state;
_ISR_Disable( level );
current_state = the_thread->current_state;
if ( current_state & state ) {
current_state =
the_thread->current_state = _States_Clear( state, current_state );
if ( _States_Is_ready( current_state ) ) {
_Priority_Add_to_bit_map( &the_thread->Priority_map );
_Chain_Append_unprotected(the_thread->ready, &the_thread->Object.Node);
_ISR_Flash( level );
/*
* If the thread that was unblocked is more important than the heir,
* then we have a new heir. This may or may not result in a
* context switch.
*
* Normal case:
* If the current thread is preemptible, then we need to do
* a context switch.
* Pseudo-ISR case:
* Even if the thread isn't preemptible, if the new heir is
* a pseudo-ISR system task, we need to do a context switch.
*/
if ( the_thread->current_priority < _Thread_Heir->current_priority ) {
_Thread_Heir = the_thread;
if ( _Thread_Executing->is_preemptible ||
the_thread->current_priority == 0 )
_Context_Switch_necessary = true;
}
}
}
_ISR_Enable( level );
}
void _Thread_Set_transient(
Thread_Control *the_thread
)
{
ISR_Level level;
uint32_t old_state;
_ISR_Disable( level );
old_state = the_thread->current_state;
the_thread->current_state = _States_Set( STATES_TRANSIENT, old_state );
if ( _States_Is_ready( old_state ) ) {
_Scheduler_Extract( the_thread );
}
_ISR_Enable( level );
}
/*
* INTERRUPT LATENCY:
* priority map
* select heir
*/
void _Thread_Clear_state(
Thread_Control *the_thread,
States_Control state
)
{
ISR_Level level;
States_Control current_state;
_ISR_Disable( level );
current_state = the_thread->current_state;
if ( current_state & state ) {
current_state =
the_thread->current_state = _States_Clear( state, current_state );
if ( _States_Is_ready( current_state ) ) {
_Scheduler_Unblock( the_thread );
}
}
_ISR_Enable( level );
}
void _Thread_Set_state(
Thread_Control *the_thread,
States_Control state
)
{
ISR_Level level;
States_Control current_state;
_ISR_Disable( level );
current_state = the_thread->current_state;
if ( _States_Is_ready( current_state ) ) {
the_thread->current_state = state;
_Scheduler_Block( _Scheduler_Get( the_thread ), the_thread );
} else {
the_thread->current_state = _States_Set( state, current_state);
}
_ISR_Enable( level );
}
void _Thread_Set_state(
Thread_Control *the_thread,
States_Control state
)
{
ISR_Level level;
_ISR_Disable( level );
if ( !_States_Is_ready( the_thread->current_state ) ) {
the_thread->current_state =
_States_Set( state, the_thread->current_state );
_ISR_Enable( level );
return;
}
the_thread->current_state = state;
_Scheduler_Block( the_thread );
_ISR_Enable( level );
}
void _Thread_Suspend(
Thread_Control *the_thread
)
{
ISR_Level level;
Chain_Control *ready;
ready = the_thread->ready;
_ISR_Disable( level );
#if defined(RTEMS_ITRON_API)
the_thread->suspend_count++;
#endif
if ( !_States_Is_ready( the_thread->current_state ) ) {
the_thread->current_state =
_States_Set( STATES_SUSPENDED, the_thread->current_state );
_ISR_Enable( level );
return;
}
the_thread->current_state = STATES_SUSPENDED;
if ( _Chain_Has_only_one_node( ready ) ) {
_Chain_Initialize_empty( ready );
_Priority_Remove_from_bit_map( &the_thread->Priority_map );
} else
_Chain_Extract_unprotected( &the_thread->Object.Node );
_ISR_Flash( level );
if ( _Thread_Is_heir( the_thread ) )
_Thread_Calculate_heir();
if ( _Thread_Is_executing( the_thread ) )
_Context_Switch_necessary = true;
_ISR_Enable( level );
}
void _Thread_Set_state(
Thread_Control *the_thread,
States_Control state
)
{
ISR_Level level;
Chain_Control *ready;
ready = the_thread->ready;
_ISR_Disable( level );
if ( !_States_Is_ready( the_thread->current_state ) ) {
the_thread->current_state =
_States_Set( state, the_thread->current_state );
_ISR_Enable( level );
return;
}
the_thread->current_state = state;
if ( _Chain_Has_only_one_node( ready ) ) {
_Chain_Initialize_empty( ready );
_Priority_Remove_from_bit_map( &the_thread->Priority_map );
} else
_Chain_Extract_unprotected( &the_thread->Object.Node );
_ISR_Flash( level );
if ( _Thread_Is_heir( the_thread ) )
_Thread_Calculate_heir();
if ( _Thread_Is_executing( the_thread ) )
_Context_Switch_necessary = TRUE;
_ISR_Enable( level );
}
void _Thread_Change_priority(
Thread_Control *the_thread,
Priority_Control new_priority,
void *arg,
Thread_Change_priority_filter filter,
bool prepend_it
)
{
ISR_lock_Context lock_context;
ISR_lock_Control *lock;
lock = _Thread_Lock_acquire( the_thread, &lock_context );
/*
* For simplicity set the priority restore hint unconditionally since this is
* an average case optimization. Otherwise complicated atomic operations
* would be necessary. Synchronize with a potential read of the resource
* count in the filter function. See also _CORE_mutex_Surrender(),
* _Thread_Set_priority_filter() and _Thread_Restore_priority_filter().
*/
the_thread->priority_restore_hint = true;
_Atomic_Fence( ATOMIC_ORDER_ACQ_REL );
/*
* Do not bother recomputing all the priority related information if
* we are not REALLY changing priority.
*/
if ( ( *filter )( the_thread, &new_priority, arg ) ) {
uint32_t my_generation;
my_generation = the_thread->priority_generation + 1;
the_thread->current_priority = new_priority;
the_thread->priority_generation = my_generation;
( *the_thread->Wait.operations->priority_change )(
the_thread,
new_priority,
the_thread->Wait.queue
);
_Thread_Lock_release( lock, &lock_context );
_Thread_State_acquire( the_thread, &lock_context );
if ( the_thread->priority_generation == my_generation ) {
if ( _States_Is_ready( the_thread->current_state ) ) {
_Scheduler_Change_priority(
the_thread,
new_priority,
prepend_it
);
} else {
_Scheduler_Update_priority( the_thread, new_priority );
}
}
_Thread_State_release( the_thread, &lock_context );
} else {
_Thread_Lock_release( lock, &lock_context );
}
}
int killinfo(
pid_t pid,
int sig,
const union sigval *value
)
{
sigset_t mask;
POSIX_API_Control *api;
uint32_t the_api;
uint32_t index;
uint32_t maximum;
Objects_Information *the_info;
Objects_Control **object_table;
Thread_Control *the_thread;
Thread_Control *interested;
Priority_Control interested_priority;
Chain_Control *the_chain;
Chain_Node *the_node;
siginfo_t siginfo_struct;
siginfo_t *siginfo;
POSIX_signals_Siginfo_node *psiginfo;
/*
* Only supported for the "calling process" (i.e. this node).
*/
if ( pid != getpid() )
rtems_set_errno_and_return_minus_one( ESRCH );
/*
* Validate the signal passed.
*/
if ( !sig )
rtems_set_errno_and_return_minus_one( EINVAL );
if ( !is_valid_signo(sig) )
rtems_set_errno_and_return_minus_one( EINVAL );
/*
* If the signal is being ignored, then we are out of here.
*/
if ( _POSIX_signals_Vectors[ sig ].sa_handler == SIG_IGN )
return 0;
/*
* P1003.1c/Draft 10, p. 33 says that certain signals should always
* be directed to the executing thread such as those caused by hardware
* faults.
*/
if ( (sig == SIGFPE) || (sig == SIGILL) || (sig == SIGSEGV ) )
return pthread_kill( pthread_self(), sig );
mask = signo_to_mask( sig );
/*
* Build up a siginfo structure
*/
siginfo = &siginfo_struct;
siginfo->si_signo = sig;
siginfo->si_code = SI_USER;
if ( !value ) {
siginfo->si_value.sival_int = 0;
} else {
siginfo->si_value = *value;
}
_Thread_Disable_dispatch();
/*
* Is the currently executing thread interested? If so then it will
* get it an execute it as soon as the dispatcher executes.
*/
the_thread = _Thread_Executing;
api = the_thread->API_Extensions[ THREAD_API_POSIX ];
if ( _POSIX_signals_Is_interested( api, mask ) ) {
goto process_it;
}
/*
* Is an interested thread waiting for this signal (sigwait())?
*
* There is no requirement on the order of threads pending on a sigwait().
*/
/* XXX violation of visibility -- need to define thread queue support */
the_chain = &_POSIX_signals_Wait_queue.Queues.Fifo;
for ( the_node = _Chain_First( the_chain );
!_Chain_Is_tail( the_chain, the_node ) ;
the_node = the_node->next ) {
the_thread = THREAD_CHAIN_NODE_TO_THREAD( the_node );
api = the_thread->API_Extensions[ THREAD_API_POSIX ];
#if defined(DEBUG_SIGNAL_PROCESSING)
printk( "Waiting Thread=%p option=0x%08x mask=0x%08x blocked=0x%08x\n",
the_thread, the_thread->Wait.option, mask, api->signals_blocked);
#endif
/*
* Is this thread is actually blocked waiting for the signal?
*/
if (the_thread->Wait.option & mask)
goto process_it;
/*
* Is this thread is blocked waiting for another signal but has
* not blocked this one?
*/
if (~api->signals_blocked & mask)
goto process_it;
}
/*
* Is any other thread interested? The highest priority interested
* thread is selected. In the event of a tie, then the following
* additional criteria is used:
*
* + ready thread over blocked
* + blocked on call interruptible by signal (can return EINTR)
* + blocked on call not interruptible by signal
*
* This looks at every thread in the system regardless of the creating API.
*
* NOTES:
*
* + rtems internal threads do not receive signals.
*/
interested = NULL;
interested_priority = PRIORITY_MAXIMUM + 1;
for (the_api = OBJECTS_CLASSIC_API; the_api <= OBJECTS_APIS_LAST; the_api++) {
/*
* This can occur when no one is interested and an API is not configured.
*/
if ( !_Objects_Information_table[ the_api ] )
continue;
the_info = _Objects_Information_table[ the_api ][ 1 ];
#if defined(RTEMS_DEBUG)
/*
* This cannot happen in the current (as of June 2009) implementation
* of initialization but at some point, the object information
* structure for a particular manager may not be installed.
*/
if ( !the_info )
continue;
#endif
maximum = the_info->maximum;
object_table = the_info->local_table;
for ( index = 1 ; index <= maximum ; index++ ) {
the_thread = (Thread_Control *) object_table[ index ];
if ( !the_thread )
continue;
#if defined(DEBUG_SIGNAL_PROCESSING)
printk("\n 0x%08x/0x%08x %d/%d 0x%08x 1",
the_thread->Object.id,
((interested) ? interested->Object.id : 0),
the_thread->current_priority, interested_priority,
the_thread->current_state
);
#endif
/*
* If this thread is of lower priority than the interested thread,
* go on to the next thread.
*/
if ( the_thread->current_priority > interested_priority )
continue;
DEBUG_STEP("2");
/*
* If this thread is not interested, then go on to the next thread.
*/
api = the_thread->API_Extensions[ THREAD_API_POSIX ];
#if defined(RTEMS_DEBUG)
if ( !api )
continue;
#endif
if ( !_POSIX_signals_Is_interested( api, mask ) )
continue;
DEBUG_STEP("3");
/*
* Now we know the thread under consideration is interested.
* If the thread under consideration is of higher priority, then
* it becomes the interested thread.
*
* NOTE: We initialized interested_priority to PRIORITY_MAXIMUM + 1
* so we never have to worry about deferencing a NULL
* interested thread.
*/
if ( the_thread->current_priority < interested_priority ) {
interested = the_thread;
interested_priority = the_thread->current_priority;
continue;
}
DEBUG_STEP("4");
/*
* Now the thread and the interested thread have the same priority.
* We have to sort through the combinations of blocked/not blocked
* and blocking interruptibutable by signal.
*
* If the interested thread is ready, don't think about changing.
*/
if ( interested && !_States_Is_ready( interested->current_state ) ) {
/* preferred ready over blocked */
DEBUG_STEP("5");
if ( _States_Is_ready( the_thread->current_state ) ) {
interested = the_thread;
interested_priority = the_thread->current_priority;
continue;
}
DEBUG_STEP("6");
/* prefer blocked/interruptible over blocked/not interruptible */
if ( !_States_Is_interruptible_by_signal(interested->current_state) ) {
DEBUG_STEP("7");
if ( _States_Is_interruptible_by_signal(the_thread->current_state) ) {
DEBUG_STEP("8");
interested = the_thread;
interested_priority = the_thread->current_priority;
continue;
}
}
}
}
}
if ( interested ) {
the_thread = interested;
goto process_it;
}
/*
* OK so no threads were interested right now. It will be left on the
* global pending until a thread receives it. The global set of threads
* can change interest in this signal in one of the following ways:
*
* + a thread is created with the signal unblocked,
* + pthread_sigmask() unblocks the signal,
* + sigprocmask() unblocks the signal, OR
* + sigaction() which changes the handler to SIG_IGN.
*/
the_thread = NULL;
goto post_process_signal;
/*
* We found a thread which was interested, so now we mark that this
* thread needs to do the post context switch extension so it can
* evaluate the signals pending.
*/
process_it:
/*
* Returns true if the signal was synchronously given to a thread
* blocked waiting for the signal.
*/
if ( _POSIX_signals_Unblock_thread( the_thread, sig, siginfo ) ) {
_Thread_Enable_dispatch();
return 0;
}
post_process_signal:
/*
* We may have woken up a thread but we definitely need to post the
* signal to the process wide information set.
*/
_POSIX_signals_Set_process_signals( mask );
if ( _POSIX_signals_Vectors[ sig ].sa_flags == SA_SIGINFO ) {
psiginfo = (POSIX_signals_Siginfo_node *)
_Chain_Get( &_POSIX_signals_Inactive_siginfo );
if ( !psiginfo ) {
_Thread_Enable_dispatch();
rtems_set_errno_and_return_minus_one( EAGAIN );
}
psiginfo->Info = *siginfo;
_Chain_Append( &_POSIX_signals_Siginfo[ sig ], &psiginfo->Node );
}
DEBUG_STEP("\n");
_Thread_Enable_dispatch();
return 0;
}
bool _Scheduler_simple_smp_Assign(
Thread_Control *consider
)
{
bool found; /* have we found a cpu to place it on? */
uint32_t found_cpu; /* CPU to place this thread */
bool blocked; /* CPU has blocked thread? */
Thread_Control *pheir; /* heir on found cpu to potentially replace */
Thread_Control *h;
Thread_Control *e;
uint32_t cpu;
/*
* Initialize various variables to indicate we have not found
* a potential core for the thread under consideration.
*/
found = false;
blocked = false;
found_cpu = 0;
pheir = NULL;
for ( cpu=0 ; cpu < _SMP_Processor_count ; cpu++ ) {
D( "SCHED CPU=%d consider=0x%08x ASSIGN\n", cpu, consider->Object.id );
/*
* If the thread under consideration is already executing or
* heir, then we don't have a better option for it.
*/
e = _Per_CPU_Information[cpu].executing;
if ( e == consider ) {
D( "SCHED CPU=%d Executing=0x%08x considering=0x%08x ASSIGNED\n",
cpu, e->Object.id, consider->Object.id );
return true;
}
if ( !_States_Is_ready( e->current_state ) ) {
pheir = e;
found_cpu = cpu;
found = true;
blocked = true;
D( "SCHED CPU=%d PHeir=0x%08x considering=0x%08x BLOCKED\n",
cpu, e->Object.id, consider->Object.id );
continue;
}
h = _Per_CPU_Information[cpu].heir;
if ( h == consider ) {
D( "SCHED CPU=%d Heir=0x%08x considering=0x%08x ASSIGNED\n",
cpu, h->Object.id, consider->Object.id );
return true;
}
if ( blocked )
continue;
/*
* If we haven't found a potential CPU to locate the thread
* under consideration on, we need to consider if this is a
* more important threads first (e.g. priority <).
*
* But when a thread changes its priority and ends up at the end of
* the priority group for the new heir, we also need to schedule
* a new heir. This is the "=" part of the check.
*/
if ( !found ) {
if ( consider->current_priority <= h->current_priority ) {
pheir = h;
found_cpu = cpu;
found = true;
D( "SCHED CPU=%d PHeir=0x%08x considering=0x%08x MAYBE #1\n",
cpu, h->Object.id, consider->Object.id );
}
continue;
}
/*
* Past this point, found is true.
*/
/*
* If we have found a potential CPU on which to make the
* thread under consideration the heir, then we need to
* check if the current CPU is a more appropriate place
* for this thread to be placed.
*
* Check 1: heir of potential CPU is more important
* then heir of current CPU. We want to
* replace the least important thread possible.
*/
if ( h->current_priority > pheir->current_priority ) {
pheir = h;
found_cpu = cpu;
D( "SCHED CPU=%d PHeir=0x%08x considering=0x%08x MAYBE #2\n",
cpu, h->Object.id, consider->Object.id );
continue;
}
if ( h->current_priority > pheir->current_priority )
continue;
/*
* If heir of potential CPU and of the current CPU are of the SAME
* priority, then which has been running longer?
*
* Which CPU has had its executing thread longer?
*/
if ( _Timestamp_Less_than(
&_Per_CPU_Information[cpu].time_of_last_context_switch,
&_Per_CPU_Information[found_cpu].time_of_last_context_switch
) ) {
pheir = h;
found_cpu = cpu;
D( "SCHED CPU=%d PHeir=0x%08x considering=0x%08x LONGER\n",
cpu, h->Object.id, consider->Object.id );
continue;
}
/*
* If we are looking at a core with a non-preemptible thread
* for potential placement, then favor a core with a preeemtible
* thread of the same priority. This should help avoid priority
* inversions and let threads run earlier.
*/
if ( !pheir->is_preemptible && h->is_preemptible ) {
D( "SCHED CPU=%d PHeir==0x%08x is NOT PREEMPTIBLE\n",
cpu, pheir->Object.id );
pheir = h;
found_cpu = cpu;
D( "SCHED CPU=%d PHeir=0x%08x considering=0x%08x PREEMPTIBLE\n",
cpu, h->Object.id, consider->Object.id );
continue;
}
}
/*
* If we found a cpu to make this thread heir of, then we
* need to consider whether we need a dispatch on that CPU.
*/
if ( found ) {
e = _Per_CPU_Information[found_cpu].executing;
D( "SCHED CPU=%d executing=0x%08x considering=0x%08x FOUND\n",
found_cpu, e->Object.id, consider->Object.id );
_Per_CPU_Information[found_cpu].heir = consider;
if ( !_States_Is_ready( e->current_state ) ) {
D( "SCHED CPU=%d executing not ready dispatch needed\n", found_cpu);
_Per_CPU_Information[found_cpu].dispatch_necessary = true;
} else if ( consider->current_priority < e->current_priority ) {
if ( e->is_preemptible || consider->current_priority == 0 ) {
D( "SCHED CPU=%d preempting\n", found_cpu);
_Per_CPU_Information[found_cpu].dispatch_necessary = true;
}
}
}
/*
* Return true to indicate we changed an heir. This indicates
* scheduling needs to examine more threads.
*/
return found;
}
ER ref_tsk(
T_RTSK *pk_rtsk,
ID tskid
)
{
register Thread_Control *the_thread;
Objects_Locations location;
Priority_Control core_priority;
if (!pk_rtsk)
return E_PAR;
the_thread = _ITRON_Task_Get( tskid, &location );
switch ( location ) {
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
return _ITRON_Task_Clarify_get_id_error( tskid );
case OBJECTS_LOCAL:
if ( location != OBJECTS_LOCAL )
return _ITRON_Task_Clarify_get_id_error( tskid );
/*
* The following are extended functions [level X ].
* XXX - tskwait, wid, wupcnt, and tskatr are presently not implemented.
*/
pk_rtsk->tskwait = 0;
pk_rtsk->wid = 0;
pk_rtsk->wupcnt = 0;
pk_rtsk->suscnt = the_thread->suspend_count;
pk_rtsk->tskatr = 0; /* XXX - Not correctly implemented */
pk_rtsk->task = (FP) the_thread->Start.entry_point;
core_priority = the_thread->Start.initial_priority;
pk_rtsk->itskpri = _ITRON_Task_Core_to_Priority( core_priority );
pk_rtsk->stksz = the_thread->Start.Initial_stack.size;
/*
* The following are required.
*/
pk_rtsk->exinf = NULL; /* extended information */
pk_rtsk->tskpri =
_ITRON_Task_Core_to_Priority(the_thread->current_priority);
/*
* Mask in the tskstat information
* Convert the task state XXX double check this
*/
pk_rtsk->tskstat = 0;
if ( the_thread == _Thread_Executing )
pk_rtsk->tskstat |= TTS_RUN;
if ( _States_Is_ready(the_thread->current_state) )
pk_rtsk->tskstat |= TTS_RDY;
if ( _States_Is_dormant( the_thread->current_state) )
pk_rtsk->tskstat |= TTS_DMT;
if ( _States_Is_suspended(the_thread->current_state) )
pk_rtsk->tskstat |= TTS_SUS;
if ( _States_Is_blocked(the_thread->current_state) )
pk_rtsk->tskstat |= TTS_WAI;
break;
}
_ITRON_return_errorno( E_OK );
}