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/**
* @file
*
* @ingroup RTEMSImplClassicSignal
*
* @brief This source file contains the implementation of
* rtems_signal_send().
*/
/*
* COPYRIGHT (c) 1989-2014.
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/rtems/signalimpl.h>
#include <rtems/rtems/modesimpl.h>
#include <rtems/rtems/tasksdata.h>
#include <rtems/score/schedulerimpl.h>
#include <rtems/score/threaddispatch.h>
#include <rtems/score/threadimpl.h>
#include <rtems/sysinit.h>
static void _Signal_Action_handler(
Thread_Control *executing,
Thread_Action *action,
ISR_lock_Context *lock_context
)
{
RTEMS_API_Control *api;
ASR_Information *asr;
rtems_signal_set signal_set;
bool normal_is_preemptible;
uint32_t normal_cpu_time_budget;
Thread_CPU_budget_algorithms normal_budget_algorithm;
uint32_t normal_isr_level;
uint32_t before_call_isr_level;
bool after_call_is_preemptible;
bool after_call_asr_is_enabled;
(void) action;
/*
* For the variable names the following notation is used. The prefix
* "normal" specifies the mode associated with the normal task execution.
* The prefix "before_call" specifies the mode set up right before the ASR
* handler is called. The prefix "after_call" specifies the mode after the
* ASR handler call returned. This mode may differ from the "before_call"
* mode since an ASR handler is free to change the task mode.
*/
api = executing->API_Extensions[ THREAD_API_RTEMS ];
asr = &api->Signal;
/* Get and clear the pending signals */
signal_set = asr->signals_pending;
_Assert( signal_set != 0 );
asr->signals_pending = 0;
/* Save normal mode */
_Assert( asr->is_enabled );
normal_is_preemptible = executing->is_preemptible;
normal_cpu_time_budget = executing->cpu_time_budget;
normal_budget_algorithm = executing->budget_algorithm;
/* Set mode for ASR processing */
executing->is_preemptible = _Modes_Is_preempt( asr->mode_set );
asr->is_enabled = !_Modes_Is_asr_disabled( asr->mode_set );
_Modes_Apply_timeslice_to_thread( asr->mode_set, executing );
before_call_isr_level = _Modes_Get_interrupt_level( asr->mode_set );
if ( executing->is_preemptible && !normal_is_preemptible ) {
Per_CPU_Control *cpu_self;
cpu_self = _Thread_Dispatch_disable_critical( lock_context );
_Scheduler_Schedule( executing );
_Thread_State_release( executing, lock_context );
_Thread_Dispatch_direct( cpu_self );
} else {
_Thread_State_release( executing, lock_context );
}
normal_isr_level = _ISR_Get_level();
_ISR_Set_level( before_call_isr_level );
/* Call the ASR handler in the ASR processing mode */
( *asr->handler )( signal_set );
/* Restore normal mode */
_ISR_Set_level( normal_isr_level );
_Thread_State_acquire( executing, lock_context );
executing->cpu_time_budget = normal_cpu_time_budget ;
executing->budget_algorithm = normal_budget_algorithm ;
after_call_is_preemptible = executing->is_preemptible;
executing->is_preemptible = normal_is_preemptible;
/*
* We do the best to avoid recursion in the ASR processing. A well behaved
* application will disable ASR processing during ASR processing. In this
* case, ASR processing is currently disabled. We do now the thread dispatch
* necessary due to a re-enabled preemption mode. This helps to avoid doing
* the next round of ASR processing recursively in _Thread_Dispatch_direct().
*/
if ( normal_is_preemptible && !after_call_is_preemptible ) {
Per_CPU_Control *cpu_self;
cpu_self = _Thread_Dispatch_disable_critical( lock_context );
_Scheduler_Schedule( executing );
_Thread_State_release( executing, lock_context );
_Thread_Dispatch_direct( cpu_self );
_Thread_State_acquire( executing, lock_context );
}
/*
* Restore the normal ASR processing mode. If we enable ASR processing and
* there are pending signals, then add us as a post-switch action. The loop
* in _Thread_Run_post_switch_actions() will continue after our return and
* call us again. This avoids a recursion.
*/
after_call_asr_is_enabled = asr->is_enabled;
asr->is_enabled = true;
if ( !after_call_asr_is_enabled && asr->signals_pending != 0 ) {
_Thread_Append_post_switch_action( executing, action );
}
}
rtems_status_code rtems_signal_send(
rtems_id id,
rtems_signal_set signal_set
)
{
Thread_Control *the_thread;
ISR_lock_Context lock_context;
RTEMS_API_Control *api;
ASR_Information *asr;
if ( signal_set == 0 ) {
return RTEMS_INVALID_NUMBER;
}
the_thread = _Thread_Get( id, &lock_context );
if ( the_thread == NULL ) {
#if defined(RTEMS_MULTIPROCESSING)
return _Signal_MP_Send( id, signal_set );
#else
return RTEMS_INVALID_ID;
#endif
}
api = the_thread->API_Extensions[ THREAD_API_RTEMS ];
asr = &api->Signal;
_Thread_State_acquire_critical( the_thread, &lock_context );
if ( asr->handler == NULL ) {
_Thread_State_release( the_thread, &lock_context );
return RTEMS_NOT_DEFINED;
}
/* Make the signals of the set pending */
asr->signals_pending |= signal_set;
if ( asr->is_enabled ) {
Per_CPU_Control *cpu_self;
_Thread_Add_post_switch_action(
the_thread,
&api->Signal_action,
_Signal_Action_handler
);
cpu_self = _Thread_Dispatch_disable_critical( &lock_context );
_Thread_State_release( the_thread, &lock_context );
_Thread_Dispatch_enable( cpu_self );
} else {
_Thread_State_release( the_thread, &lock_context );
}
return RTEMS_SUCCESSFUL;
}
#if defined(RTEMS_MULTIPROCESSING)
static void _Signal_MP_Initialize( void )
{
_MPCI_Register_packet_processor(
MP_PACKET_SIGNAL,
_Signal_MP_Process_packet
);
}
RTEMS_SYSINIT_ITEM(
_Signal_MP_Initialize,
RTEMS_SYSINIT_CLASSIC_SIGNAL_MP,
RTEMS_SYSINIT_ORDER_MIDDLE
);
#endif
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