89 lines
3.0 KiB
C
89 lines
3.0 KiB
C
/****************************************************************************
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* sched/signal/sig_usleep.c
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*
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership. The
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* ASF licenses this file to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance with the
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* License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <signal.h>
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#include <assert.h>
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#include <errno.h>
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#include <nuttx/signal.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: nxsig_usleep
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*
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* Description:
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* The nxsig_usleep() function will cause the calling thread to be
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* suspended from execution until either the number of real-time
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* microseconds specified by the argument 'usec' has elapsed or a signal
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* is delivered to the calling thread. The suspension time may be longer
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* than requested due to the scheduling of other activity by the system.
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*
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* This is an internal OS interface. It is functionally equivalent to
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* the standard nxsig_usleep() application interface except that:
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*
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* - It is not a cancellation point, and
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* - It does not modify the errno value.
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*
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* See the description of usleep() for additional information that is not
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* duplicated here.
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*
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* Input Parameters:
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* usec - the number of microseconds to wait.
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*
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* Returned Value:
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* This is an internal OS interface and should not be used by applications.
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* It follows the NuttX internal error return policy: Zero (OK) is
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* returned on success. A negated errno value is returned on failure.
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*
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****************************************************************************/
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int nxsig_usleep(useconds_t usec)
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{
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struct timespec rqtp;
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time_t sec;
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int ret = 0;
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if (usec)
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{
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/* Let nxsig_nanosleep() do all of the work. */
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sec = USEC2SEC(usec);
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rqtp.tv_sec = sec;
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rqtp.tv_nsec = (usec - (sec * USEC_PER_SEC)) * NSEC_PER_USEC;
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ret = nxsig_nanosleep(&rqtp, NULL);
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}
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return ret;
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}
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