/****************************************************************************
 * arch/sim/src/sim/sim_releasepending.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sched.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/sched.h>

#include "sched/sched.h"
#include "sim_internal.h"

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: up_release_pending
 *
 * Description:
 *   Release and ready-to-run tasks that have
 *   collected in the pending task list.  This can call a
 *   context switch if a new task is placed at the head of
 *   the ready to run list.
 *
 ****************************************************************************/

void up_release_pending(void)
{
  struct tcb_s *rtcb = this_task();

  sinfo("From TCB=%p\n", rtcb);

  /* Merge the g_pendingtasks list into the ready-to-run task list */

  /* sched_lock(); */

  if (nxsched_merge_pending())
    {
      /* The currently active task has changed!  We will need to switch
       * contexts.
       *
       * Update scheduler parameters.
       */

      nxsched_suspend_scheduler(rtcb);

      /* TODO */

      if (CURRENT_REGS)
        {
          ASSERT(false);
        }

      /* Copy the exception context into the TCB of the task that was
       * currently active. if setjmp returns a non-zero value, then
       * this is really the previously running task restarting!
       */

      else if (!setjmp(rtcb->xcp.regs))
        {
          /* Restore the exception context of the rtcb at the (new) head
           * of the ready-to-run task list.
           */

          rtcb = this_task();
          sinfo("New Active Task TCB=%p\n", rtcb);

          /* Update scheduler parameters */

          nxsched_resume_scheduler(rtcb);

          /* Restore the cpu lock */

          restore_critical_section();

          /* Then switch contexts */

          longjmp(rtcb->xcp.regs, 1);
        }
      else
        {
          /* The way that we handle signals in the simulation is kind of
           * a kludge.  This would be unsafe in a truly multi-threaded,
           * interrupt driven environment.
           */

          sim_sigdeliver();
        }
    }
}
