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/**
* @file
*
* @brief POSIX Signals Thread Unlock
* @ingroup POSIX_SIGNALS
*/
/*
* COPYRIGHT (c) 1989-2007.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <errno.h>
#include <pthread.h>
#include <signal.h>
#include <rtems/system.h>
#include <rtems/score/isr.h>
#include <rtems/score/threadimpl.h>
#include <rtems/score/threadqimpl.h>
#include <rtems/score/watchdogimpl.h>
#include <rtems/score/wkspace.h>
#include <rtems/seterr.h>
#include <rtems/posix/threadsup.h>
#include <rtems/posix/psignalimpl.h>
#include <rtems/posix/pthreadimpl.h>
#include <stdio.h>
static void _POSIX_signals_Check_signal(
POSIX_API_Control *api,
int signo,
bool is_global
)
{
siginfo_t siginfo_struct;
sigset_t saved_signals_unblocked;
if ( ! _POSIX_signals_Clear_signals( api, signo, &siginfo_struct,
is_global, true, true ) )
return;
/*
* Since we made a union of these, only one test is necessary but this is
* safer.
*/
#if defined(RTEMS_DEBUG)
assert( _POSIX_signals_Vectors[ signo ].sa_handler ||
_POSIX_signals_Vectors[ signo ].sa_sigaction );
#endif
/*
* Just to prevent sending a signal which is currently being ignored.
*/
if ( _POSIX_signals_Vectors[ signo ].sa_handler == SIG_IGN )
return;
/*
* Block the signals requested in sa_mask
*/
saved_signals_unblocked = api->signals_unblocked;
api->signals_unblocked &= ~_POSIX_signals_Vectors[ signo ].sa_mask;
/*
* Here, the signal handler function executes
*/
switch ( _POSIX_signals_Vectors[ signo ].sa_flags ) {
case SA_SIGINFO:
(*_POSIX_signals_Vectors[ signo ].sa_sigaction)(
signo,
&siginfo_struct,
NULL /* context is undefined per 1003.1b-1993, p. 66 */
);
break;
default:
(*_POSIX_signals_Vectors[ signo ].sa_handler)( signo );
break;
}
/*
* Restore the previous set of unblocked signals
*/
api->signals_unblocked = saved_signals_unblocked;
}
static void _POSIX_signals_Action_handler(
Thread_Control *executing,
Thread_Action *action,
ISR_lock_Context *lock_context
)
{
POSIX_API_Control *api;
int signo;
uint32_t hold_errno;
(void) action;
_Thread_State_release( executing, lock_context );
api = executing->API_Extensions[ THREAD_API_POSIX ];
/*
* We need to ensure that if the signal handler executes a call
* which overwrites the unblocking status, we restore it.
*/
hold_errno = executing->Wait.return_code;
/*
* api may be NULL in case of a thread close in progress
*/
if ( !api )
return;
/*
* In case the executing thread is blocked or about to block on something
* that uses the thread wait information, then this is a kernel bug.
*/
_Assert(
( _Thread_Wait_flags_get( executing )
& ( THREAD_WAIT_STATE_BLOCKED | THREAD_WAIT_STATE_INTEND_TO_BLOCK ) ) == 0
);
/*
* If we invoke any user code, there is the possibility that
* a new signal has been posted that we should process so we
* restart the loop if a signal handler was invoked.
*
* The first thing done is to check there are any signals to be
* processed at all. No point in doing this loop otherwise.
*/
while (1) {
Thread_queue_Context queue_context;
_Thread_queue_Context_initialize( &queue_context );
_POSIX_signals_Acquire( &queue_context );
if ( !(api->signals_unblocked &
(api->signals_pending | _POSIX_signals_Pending)) ) {
_POSIX_signals_Release( &queue_context );
break;
}
_POSIX_signals_Release( &queue_context );
for ( signo = SIGRTMIN ; signo <= SIGRTMAX ; signo++ ) {
_POSIX_signals_Check_signal( api, signo, false );
_POSIX_signals_Check_signal( api, signo, true );
}
/* Unfortunately - nothing like __SIGFIRSTNOTRT in newlib signal .h */
for ( signo = SIGHUP ; signo <= __SIGLASTNOTRT ; signo++ ) {
_POSIX_signals_Check_signal( api, signo, false );
_POSIX_signals_Check_signal( api, signo, true );
}
}
executing->Wait.return_code = hold_errno;
}
static bool _POSIX_signals_Unblock_thread_done(
Thread_Control *the_thread,
POSIX_API_Control *api,
bool status
)
{
ISR_lock_Context lock_context;
_Thread_State_acquire( the_thread, &lock_context );
_Thread_Add_post_switch_action(
the_thread,
&api->Signal_action,
_POSIX_signals_Action_handler
);
_Thread_State_release( the_thread, &lock_context );
return status;
}
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 );
}
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