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/*
* Copyright (c) 2016 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* 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/rtems/tasks.h>
#include <rtems/score/schedulerimpl.h>
#include <rtems/config.h>
#if defined(RTEMS_SMP)
typedef struct {
const Scheduler_Control *scheduler;
rtems_status_code status;
} Scheduler_Processor_removal_context;
static bool _Scheduler_Check_processor_removal(
Thread_Control *the_thread,
void *arg
)
{
Scheduler_Processor_removal_context *iter_context;
Thread_queue_Context queue_context;
ISR_lock_Context state_context;
if ( the_thread->is_idle ) {
return false;
}
iter_context = arg;
_Thread_queue_Context_initialize( &queue_context );
_Thread_Wait_acquire( the_thread, &queue_context );
_Thread_State_acquire_critical( the_thread, &state_context );
if ( _Thread_Scheduler_get_home( the_thread ) == iter_context->scheduler ) {
iter_context->status = RTEMS_RESOURCE_IN_USE;
}
_Thread_State_release_critical( the_thread, &state_context );
_Thread_Wait_release( the_thread, &queue_context );
return iter_context->status != RTEMS_SUCCESSFUL;
}
#endif
rtems_status_code rtems_scheduler_remove_processor(
rtems_id scheduler_id,
uint32_t cpu_index
)
{
const Scheduler_Control *scheduler;
#if defined(RTEMS_SMP)
uint32_t processor_count;
Scheduler_Processor_removal_context iter_context;
ISR_lock_Context lock_context;
Scheduler_Context *scheduler_context;
Per_CPU_Control *cpu;
Per_CPU_Control *cpu_self;
#endif
scheduler = _Scheduler_Get_by_id( scheduler_id );
if ( scheduler == NULL ) {
return RTEMS_INVALID_ID;
}
if ( cpu_index >= rtems_configuration_get_maximum_processors() ) {
return RTEMS_INVALID_NUMBER;
}
#if defined(RTEMS_SMP)
iter_context.scheduler = scheduler;
iter_context.status = RTEMS_SUCCESSFUL;
scheduler_context = _Scheduler_Get_context( scheduler );
cpu = _Per_CPU_Get_by_index( cpu_index );
_Objects_Allocator_lock();
if ( cpu->Scheduler.control != scheduler ) {
_Objects_Allocator_unlock();
return RTEMS_INVALID_NUMBER;
}
/*
* This prevents the selection of this scheduler instance by new threads in
* case the processor count changes to zero.
*/
_ISR_lock_ISR_disable( &lock_context );
_Scheduler_Acquire_critical( scheduler, &lock_context );
processor_count = scheduler_context->processor_count - 1;
scheduler_context->processor_count = processor_count;
_Scheduler_Release_critical( scheduler, &lock_context );
_ISR_lock_ISR_enable( &lock_context );
if ( processor_count == 0 ) {
_Thread_Iterate( _Scheduler_Check_processor_removal, &iter_context );
}
_ISR_lock_ISR_disable( &lock_context );
_Scheduler_Acquire_critical( scheduler, &lock_context );
if ( iter_context.status == RTEMS_SUCCESSFUL ) {
Thread_Control *idle;
Scheduler_Node *scheduler_node;
cpu->Scheduler.control = NULL;
cpu->Scheduler.context = NULL;
idle = ( *scheduler->Operations.remove_processor )( scheduler, cpu );
cpu->Scheduler.idle_if_online_and_unused = idle;
scheduler_node = _Thread_Scheduler_get_home_node( idle );
_Priority_Plain_extract(
&scheduler_node->Wait.Priority,
&idle->Real_priority
);
_Assert( _Priority_Is_empty( &scheduler_node->Wait.Priority ) );
_Chain_Extract_unprotected( &scheduler_node->Thread.Wait_node );
_Assert( _Chain_Is_empty( &idle->Scheduler.Wait_nodes ) );
_Chain_Extract_unprotected( &scheduler_node->Thread.Scheduler_node.Chain );
_Assert( _Chain_Is_empty( &idle->Scheduler.Scheduler_nodes ) );
} else {
++scheduler_context->processor_count;
}
cpu_self = _Thread_Dispatch_disable_critical( &lock_context );
_Scheduler_Release_critical( scheduler, &lock_context );
_ISR_lock_ISR_enable( &lock_context );
_Thread_Dispatch_enable( cpu_self );
_Objects_Allocator_unlock();
return iter_context.status;
#else
return RTEMS_RESOURCE_IN_USE;
#endif
}
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