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38 lines
1.2 KiB
C
38 lines
1.2 KiB
C
/*
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* Copyright (c) 1996 W. Richard Stevens. All rights reserved.
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* Permission to use or modify this software and its documentation only for
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* educational purposes and without fee is hereby granted, provided that
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* the above copyright notice appear in all copies. The author makes no
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* representations about the suitability of this software for any purpose.
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* It is provided "as is" without express or implied warranty.
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*/
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#include <sys/types.h>
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#include <sys/time.h>
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#include <errno.h>
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#include <stddef.h>
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void
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sleep_us(unsigned int nusecs)
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{
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struct timeval tval;
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for ( ; ; ) {
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tval.tv_sec = nusecs / 1000000;
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tval.tv_usec = nusecs % 1000000;
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if (select(0, NULL, NULL, NULL, &tval) == 0)
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break; /* all OK */
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/*
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* Note than on an interrupted system call (i.e, SIGIO) there's not
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* much we can do, since the timeval{} isn't updated with the time
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* remaining. We could obtain the clock time before the call, and
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* then obtain the clock time here, subtracting them to determine
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* how long select() blocked before it was interrupted, but that
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* seems like too much work :-)
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*/
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if (errno == EINTR)
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continue;
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err_sys("sleep_us: select error");
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}
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}
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