/* XXX this routine could probably be cleaned up */
bool _POSIX_signals_Unblock_thread(
Thread_Control *the_thread,
int signo,
siginfo_t *info
)
{
POSIX_API_Control *api;
sigset_t mask;
siginfo_t *the_info = NULL;
api = the_thread->API_Extensions[ THREAD_API_POSIX ];
mask = signo_to_mask( signo );
/*
* Is the thread is specifically waiting for a signal?
*/
if ( _States_Is_interruptible_signal( the_thread->current_state ) ) {
if ( (the_thread->Wait.option & mask) || (~api->signals_blocked & mask) ) {
the_thread->Wait.return_code = EINTR;
the_info = (siginfo_t *) the_thread->Wait.return_argument;
if ( !info ) {
the_info->si_signo = signo;
the_info->si_code = SI_USER;
the_info->si_value.sival_int = 0;
} else {
*the_info = *info;
}
_Thread_queue_Extract_with_proxy( the_thread );
return true;
}
/*
* This should only be reached via pthread_kill().
*/
return false;
}
/*
* Thread is not waiting due to a sigwait.
*/
if ( ~api->signals_blocked & mask ) {
/*
* The thread is interested in this signal. We are going
* to post it. We have a few broad cases:
* + If it is blocked on an interruptible signal, THEN
* we unblock the thread.
* + If it is in the ready state AND
* we are sending from an ISR AND
* it is the interrupted thread AND
* it is not blocked, THEN
* we need to dispatch at the end of this ISR.
* + Any other combination, do nothing.
*/
the_thread->do_post_task_switch_extension = true;
if ( _States_Is_interruptible_by_signal( the_thread->current_state ) ) {
the_thread->Wait.return_code = EINTR;
/*
* In pthread_cond_wait, a thread will be blocking on a thread
* queue, but is also interruptible by a POSIX signal.
*/
if ( _States_Is_waiting_on_thread_queue(the_thread->current_state) )
_Thread_queue_Extract_with_proxy( the_thread );
else if ( _States_Is_delaying(the_thread->current_state) ){
(void) _Watchdog_Remove( &the_thread->Timer );
_Thread_Unblock( the_thread );
}
} else if ( the_thread->current_state == STATES_READY ) {
if ( _ISR_Is_in_progress() && _Thread_Is_executing( the_thread ) )
_ISR_Signals_to_thread_executing = true;
}
}
return false;
}
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 _POSIX_signals_Unblock_thread(
Thread_Control *the_thread,
int signo,
siginfo_t *info
)
{
POSIX_API_Control *api;
sigset_t mask;
siginfo_t *the_info = NULL;
api = the_thread->API_Extensions[ THREAD_API_POSIX ];
mask = signo_to_mask( signo );
/*
* Is the thread is specifically waiting for a signal?
*/
if ( _States_Is_interruptible_signal( the_thread->current_state ) ) {
if ( (the_thread->Wait.option & mask) || (api->signals_unblocked & mask) ) {
the_thread->Wait.return_code = STATUS_INTERRUPTED;
the_info = (siginfo_t *) the_thread->Wait.return_argument;
if ( !info ) {
the_info->si_signo = signo;
the_info->si_code = SI_USER;
the_info->si_value.sival_int = 0;
} else {
*the_info = *info;
}
_Thread_queue_Extract_with_proxy( the_thread );
return _POSIX_signals_Unblock_thread_done( the_thread, api, true );
}
/*
* This should only be reached via pthread_kill().
*/
return _POSIX_signals_Unblock_thread_done( the_thread, api, false );
}
/*
* Thread is not waiting due to a sigwait.
*/
if ( api->signals_unblocked & mask ) {
/*
* The thread is interested in this signal. We are going
* to post it. We have a few broad cases:
* + If it is blocked on an interruptible signal, THEN
* we unblock the thread.
* + If it is in the ready state AND
* we are sending from an ISR AND
* it is the interrupted thread AND
* it is not blocked, THEN
* we need to dispatch at the end of this ISR.
* + Any other combination, do nothing.
*/
if ( _States_Is_interruptible_by_signal( the_thread->current_state ) ) {
the_thread->Wait.return_code = STATUS_INTERRUPTED;
_Thread_queue_Extract_with_proxy( the_thread );
}
}
return _POSIX_signals_Unblock_thread_done( the_thread, api, false );
}
