/**************************************************************************** * libs/libc/wqueue/work_cancel.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 #include #include #include #include #include #include "wqueue/wqueue.h" #if defined(CONFIG_LIBC_USRWORK) && !defined(__KERNEL__) /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Name: work_qcancel * * Description: * Cancel previously queued work. This removes work from the work queue. * After work has been cancelled, it may be requeued by calling * work_queue() again. * * Input Parameters: * wqueue - The work queue * work - The previously queue work structure to cancel * * Returned Value: * Zero (OK) on success, a negated errno on failure. This error may be * reported: * * -ENOENT - There is no such work queued. * -EINVAL - An invalid work queue was specified * ****************************************************************************/ static int work_qcancel(FAR struct usr_wqueue_s *wqueue, FAR struct work_s *work) { FAR sq_entry_t *prev = NULL; FAR sq_entry_t *curr; int ret = -ENOENT; int semcount; DEBUGASSERT(work != NULL); /* Get exclusive access to the work queue */ while (_SEM_WAIT(&wqueue->lock) < 0); /* Cancelling the work is simply a matter of removing the work structure * from the work queue. This must be done with interrupts disabled because * new work is typically added to the work queue from interrupt handlers. */ if (work->worker != NULL) { /* Search the work activelist for the target work. We can't * use sq_rem to do this because there are additional operations that * need to be done. */ curr = wqueue->q.head; while (curr && curr != &work->u.s.sq) { prev = curr; curr = curr->flink; } /* Check if the work was found in the list. If not, then an OS * error has occurred because the work is marked active! */ DEBUGASSERT(curr); /* Now, remove the work from the work queue */ if (prev) { /* Remove the work from mid- or end-of-queue */ sq_remafter(prev, &wqueue->q); } else { /* Remove the work at the head of the queue */ sq_remfirst(&wqueue->q); _SEM_GETVALUE(&wqueue->wake, &semcount); if (semcount < 1) { _SEM_POST(&wqueue->wake); } } work->worker = NULL; ret = OK; } _SEM_POST(&wqueue->lock); return ret; } /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: work_cancel * * Description: * Cancel previously queued user-mode work. This removes work from the * user mode work queue. After work has been cancelled, it may be * requeued by calling work_queue() again. * * Input Parameters: * qid - The work queue ID (must be USRWORK) * work - The previously queued work structure to cancel * * Returned Value: * Zero (OK) on success, a negated errno on failure. This error may be * reported: * * -ENOENT - There is no such work queued. * ****************************************************************************/ int work_cancel(int qid, FAR struct work_s *work) { if (qid == USRWORK) { return work_qcancel(&g_usrwork, work); } else { return -EINVAL; } } #endif /* CONFIG_LIBC_USRWORK && !__KERNEL__ */