nuttx/libs/libc/wqueue/work_queue.c

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/****************************************************************************
* libs/libc/wqueue/work_queue.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 <stdint.h>
#include <signal.h>
#include <assert.h>
#include <queue.h>
#include <errno.h>
#include <nuttx/clock.h>
#include <nuttx/wqueue.h>
#include "wqueue/wqueue.h"
#if defined(CONFIG_LIB_USRWORK) && !defined(__KERNEL__)
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: work_qqueue
*
* Description:
* Queue work to be performed at a later time. All queued work will be
* performed on the worker thread of execution (not the caller's).
*
* The work structure is allocated by caller, but completely managed by
* the work queue logic. The caller should never modify the contents of
* the work queue structure; the caller should not call work_qqueue()
* again until either (1) the previous work has been performed and removed
* from the queue, or (2) work_cancel() has been called to cancel the work
* and remove it from the work queue.
*
* Input Parameters:
* qid - The work queue ID (index)
* work - The work structure to queue
* worker - The worker callback to be invoked. The callback will be
* invoked on the worker thread of execution.
* arg - The argument that will be passed to the worker callback when
* int is invoked.
* delay - Delay (in clock ticks) from the time queue until the worker
* is invoked. Zero means to perform the work immediately.
*
* Returned Value:
* Zero on success, a negated errno on failure
*
****************************************************************************/
static int work_qqueue(FAR struct usr_wqueue_s *wqueue,
FAR struct work_s *work, worker_t worker,
FAR void *arg, clock_t delay)
{
DEBUGASSERT(work != NULL);
/* Get exclusive access to the work queue */
while (work_lock() < 0);
/* Is there already pending work? */
if (work->worker != NULL)
{
/* Remove the entry from the work queue. It will be requeued at the
* end of the work queue.
*/
dq_rem((FAR dq_entry_t *)work, &wqueue->q);
}
/* Initialize the work structure */
work->worker = worker; /* Work callback. non-NULL means queued */
work->arg = arg; /* Callback argument */
work->delay = delay; /* Delay until work performed */
/* Now, time-tag that entry and put it in the work queue. */
work->qtime = clock(); /* Time work queued */
dq_addlast((FAR dq_entry_t *)work, &wqueue->q);
kill(wqueue->pid, SIGWORK); /* Wake up the worker thread */
work_unlock();
return OK;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: work_queue
*
* Description:
* Queue user-mode work to be performed at a later time. All queued work
* will be performed on the worker thread of execution (not the caller's).
*
* The work structure is allocated and must be initialized to all zero by
* the caller. Otherwise, the work structure is completely managed by the
* work queue logic. The caller should never modify the contents of the
* work queue structure directly. If work_queue() is called before the
* previous work has been performed and removed from the queue, then any
* pending work will be canceled and lost.
*
* Input Parameters:
* qid - The work queue ID (index)
* work - The work structure to queue
* worker - The worker callback to be invoked. The callback will be
* invoked on the worker thread of execution.
* arg - The argument that will be passed to the worker callback when
* int is invoked.
* delay - Delay (in clock ticks) from the time queue until the worker
* is invoked. Zero means to perform the work immediately.
*
* Returned Value:
* Zero on success, a negated errno on failure
*
****************************************************************************/
int work_queue(int qid, FAR struct work_s *work, worker_t worker,
FAR void *arg, clock_t delay)
{
if (qid == USRWORK)
{
return work_qqueue(&g_usrwork, work, worker, arg, delay);
}
else
{
return -EINVAL;
}
}
#endif /* CONFIG_LIB_USRWORK && !__KERNEL__ */