text: /****************************************************************************
   * sched/wqueue/kwork_signal.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 <signal.h>
  #include <errno.h>
  
  #include <nuttx/wqueue.h>
  #include <nuttx/signal.h>
  
  #include "wqueue/wqueue.h"
  
  #ifdef CONFIG_SCHED_WORKQUEUE
  
  /****************************************************************************
   * Public Functions
   ****************************************************************************/
  
  /****************************************************************************
   * Name: work_signal
   *
   * Description:
   *   Signal the worker thread to process the work queue now.  This function
   *   is used internally by the work logic but could also be used by the
   *   user to force an immediate re-assessment of pending work.
   *
   * Input Parameters:
   *   qid    - The work queue ID
   *
   * Returned Value:
   *   Zero (OK) on success, a negated errno value on failure
   *
   ****************************************************************************/
  
  int work_signal(int qid)
  {
    FAR struct kwork_wqueue_s *work;
    int threads;
    int i;
  
    /* Get the process ID of the worker thread */
  
  #ifdef CONFIG_SCHED_HPWORK
    if (qid == HPWORK)
      {
        work = (FAR struct kwork_wqueue_s *)&g_hpwork;
        threads = CONFIG_SCHED_HPNTHREADS;
      }
    else
  #endif
  #ifdef CONFIG_SCHED_LPWORK
    if (qid == LPWORK)
      {
        work = (FAR struct kwork_wqueue_s *)&g_lpwork;
        threads = CONFIG_SCHED_LPNTHREADS;
      }
    else
  #endif
      {
        return -EINVAL;
      }
  
    /* Find an IDLE worker thread */
  
    for (i = 0; i < threads; i++)
      {
        /* Is this worker thread busy? */
  
        if (!work->worker[i].busy)
          {
            /* No.. select this thread */
  
            break;
          }
      }
  
    /* If all of the IDLE threads are busy, then just return successfully */
  
    if (i >= threads)
      {
        return OK;
      }
  
    /* Otherwise, signal the first IDLE thread found */
  
    return nxsig_kill(work->worker[i].pid, SIGWORK);
  }
  
  #endif /* CONFIG_SCHED_WORKQUEUE */
  