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RIOT/core/cib.c
2014-02-11 18:45:06 +01:00

69 lines
1.2 KiB
C

/*
* Copyright (C) 2013 Freie Universität Berlin
*
* This file subject to the terms and conditions of the GNU Lesser General
* Public License. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @ingroup core_util
* @{
*
* @file cib.c
* @brief Circular integer buffer implementation
*
* @author Freie Universität Berlin, Computer Systems & Telematics, FeuerWhere project
* @author Kaspar Schleiser <kaspar@schleiser.de>
*
* @}
*/
#include "cib.h"
void cib_init(cib_t *cib, unsigned int size)
{
cib->read_count = 0;
cib->write_count = 0;
cib->complement = 0 - size;
}
int cib_avail(cib_t *cib)
{
return (int)(cib->write_count - cib->read_count);
}
int cib_get(cib_t *cib)
{
int avail = cib_avail(cib);
if (avail > 0) {
return (int)(cib->read_count++ & ~cib->complement);
}
return -1;
}
int cib_put(cib_t *cib)
{
int avail = cib_avail(cib);
if ((int)(avail + cib->complement) < 0) {
return (int)(cib->write_count++ & ~(cib->complement));
}
return -1;
}
/*
int main() {
cib_t cib;
cib_init(&cib, 0);
int res = cib_get(&cib);
printf("%i\n", res);
}
*/