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/**
* @file
*
* @brief Dispatch Thread
* @ingroup ScoreThread
*/
/*
* COPYRIGHT (c) 1989-2009.
* On-Line Applications Research Corporation (OAR).
*
* Copyright (c) 2014, 2016 embedded brains GmbH.
*
* 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 <rtems/score/threaddispatch.h>
#include <rtems/score/assert.h>
#include <rtems/score/isr.h>
#include <rtems/score/threadimpl.h>
#include <rtems/score/todimpl.h>
#include <rtems/score/userextimpl.h>
#include <rtems/score/wkspace.h>
#include <rtems/config.h>
#if __RTEMS_ADA__
void *rtems_ada_self;
#endif
#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
Thread_Control *_Thread_Allocated_fp;
#endif
CHAIN_DEFINE_EMPTY( _User_extensions_Switches_list );
static Thread_Action *_Thread_Get_post_switch_action(
Thread_Control *executing
)
{
Chain_Control *chain = &executing->Post_switch_actions.Chain;
return (Thread_Action *) _Chain_Get_unprotected( chain );
}
static void _Thread_Run_post_switch_actions( Thread_Control *executing )
{
ISR_lock_Context lock_context;
Thread_Action *action;
_Thread_State_acquire( executing, &lock_context );
action = _Thread_Get_post_switch_action( executing );
while ( action != NULL ) {
_Chain_Set_off_chain( &action->Node );
( *action->handler )( executing, action, &lock_context );
_Thread_State_acquire( executing, &lock_context );
action = _Thread_Get_post_switch_action( executing );
}
_Thread_State_release( executing, &lock_context );
}
void _Thread_Do_dispatch( Per_CPU_Control *cpu_self, ISR_Level level )
{
Thread_Control *executing;
_Assert( cpu_self->thread_dispatch_disable_level == 1 );
executing = cpu_self->executing;
do {
Thread_Control *heir = _Thread_Get_heir_and_make_it_executing( cpu_self );
/*
* When the heir and executing are the same, then we are being
* requested to do the post switch dispatching. This is normally
* done to dispatch signals.
*/
if ( heir == executing )
goto post_switch;
/*
* Since heir and executing are not the same, we need to do a real
* context switch.
*/
#if __RTEMS_ADA__
executing->rtems_ada_self = rtems_ada_self;
rtems_ada_self = heir->rtems_ada_self;
#endif
if ( heir->budget_algorithm == THREAD_CPU_BUDGET_ALGORITHM_RESET_TIMESLICE )
heir->cpu_time_budget = rtems_configuration_get_ticks_per_timeslice();
/*
* On SMP the complete context switch must be atomic with respect to one
* processor. See also _Thread_Handler() since _Context_switch() may branch
* to this function.
*/
#if !defined( RTEMS_SMP )
_ISR_Local_enable( level );
#endif
_User_extensions_Thread_switch( executing, heir );
_Thread_Save_fp( executing );
_Context_Switch( &executing->Registers, &heir->Registers );
_Thread_Restore_fp( executing );
/*
* We have to obtain this value again after the context switch since the
* heir thread may have migrated from another processor. Values from the
* stack or non-volatile registers reflect the old execution environment.
*/
cpu_self = _Per_CPU_Get();
#if !defined( RTEMS_SMP )
_ISR_Local_disable( level );
#endif
} while (
#if defined( RTEMS_SMP )
false
#else
cpu_self->dispatch_necessary
#endif
);
post_switch:
_Assert( cpu_self->thread_dispatch_disable_level == 1 );
cpu_self->thread_dispatch_disable_level = 0;
_Profiling_Thread_dispatch_enable( cpu_self, 0 );
_ISR_Local_enable( level );
_Thread_Run_post_switch_actions( executing );
}
void _Thread_Dispatch( void )
{
ISR_Level level;
Per_CPU_Control *cpu_self;
_ISR_Local_disable( level );
cpu_self = _Per_CPU_Get();
if ( cpu_self->dispatch_necessary ) {
_Profiling_Thread_dispatch_disable( cpu_self, 0 );
cpu_self->thread_dispatch_disable_level = 1;
_Thread_Do_dispatch( cpu_self, level );
} else {
_ISR_Local_enable( level );
}
}
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