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49 lines
928 B
C
49 lines
928 B
C
/*
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* Copyright (C) 2015 Kaspar Schleiser <kaspar@schleiser.de>
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*
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* This file is subject to the terms and conditions of the GNU Lesser
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* General Public License v2.1. See the file LICENSE in the top level
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* directory for more details.
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*/
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/**
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* @ingroup sys_util
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* @{
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*
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* @file
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* @brief Bitfield auxillary functions
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*
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* @author Kaspar Schleiser <kaspar@schleiser.de>
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*
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* @}
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*/
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#include <stdint.h>
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#include "bitfield.h"
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#include "irq.h"
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int bf_get_unset(uint8_t field[], int size)
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{
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int result = -1;
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int nbytes = (size + 7) / 8;
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int i = 0;
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unsigned state = disableIRQ();
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/* skip full bytes */
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for (int j = 0; (j < nbytes) && (field[j] == 255); j++) {
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i += 8;
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}
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for (; i < size; i++) {
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if (!bf_isset(field, i)) {
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bf_set(field, i);
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result = i;
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break;
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}
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}
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restoreIRQ(state);
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return(result);
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}
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