/**
 * @file
 *
 * @ingroup RTEMSScoreThread
 *
 * @brief This source file contains the implementation of
 *   _Thread_Get_CPU_time_used() and _Thread_Get_CPU_time_used_locked().
 */

/*
 * 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.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <rtems/score/threadimpl.h>
#include <rtems/score/schedulerimpl.h>

static bool _Thread_Is_scheduled( const Thread_Control *the_thread )
{
#if defined(RTEMS_SMP)
  return the_thread->Scheduler.state == THREAD_SCHEDULER_SCHEDULED;
#else
  return _Thread_Is_executing( the_thread );
#endif
}

Timestamp_Control _Thread_Get_CPU_time_used_locked(
  Thread_Control *the_thread
)
{
  _Assert( _Thread_State_is_owner( the_thread ) );
  _Assert(
    _ISR_lock_Is_owner(
      &_Scheduler_Get_context( _Thread_Scheduler_get_home( the_thread ) )->Lock
    )
  );

  if ( _Thread_Is_scheduled( the_thread ) ) {
    _Thread_Update_CPU_time_used( the_thread, _Thread_Get_CPU( the_thread ) );
  }

  return the_thread->cpu_time_used;
}

Timestamp_Control _Thread_Get_CPU_time_used( Thread_Control *the_thread )
{
  const Scheduler_Control *scheduler;
  ISR_lock_Context         state_lock_context;
  ISR_lock_Context         scheduler_lock_context;
  Timestamp_Control        cpu_time_used;

  _Thread_State_acquire( the_thread, &state_lock_context );
  scheduler = _Thread_Scheduler_get_home( the_thread );
  _Scheduler_Acquire_critical( scheduler, &scheduler_lock_context );

  cpu_time_used = _Thread_Get_CPU_time_used_locked( the_thread );

  _Scheduler_Release_critical( scheduler, &scheduler_lock_context );
  _Thread_State_release( the_thread, &state_lock_context );

  return cpu_time_used;
}