Added ringbufindex module

core/lib/ringbufindex.h

@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2015, SICS Swedish ICT.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is part of the Contiki operating system.
+ *
+ */
+
+/**
+ * \file
+ *         Header file for the ringbufindex library
+ * \author
+ *         Simon Duquennoy <simonduq@sics.se>
+ */
+
+#ifndef __RINGBUFINDEX_H__
+#define __RINGBUFINDEX_H__
+
+#include "contiki-conf.h"
+
+struct ringbufindex {
+  uint8_t mask;
+  /* These must be 8-bit quantities to avoid race conditions. */
+  uint8_t put_ptr, get_ptr;
+};
+
+/* Initialize a ring buffer. The size must be a power of two */
+void ringbufindex_init(struct ringbufindex *r, uint8_t size);
+/* Put one element to the ring buffer */
+int ringbufindex_put(struct ringbufindex *r);
+/* Check if there is space to put an element.
+ * Return the index where the next element is to be added */
+int ringbufindex_peek_put(const struct ringbufindex *r);
+/* Remove the first element and return its index */
+int ringbufindex_get(struct ringbufindex *r);
+/* Return the index of the first element
+ * (which will be removed if calling ringbufindex_peek) */
+int ringbufindex_peek_get(const struct ringbufindex *r);
+/* Return the ring buffer size */
+int ringbufindex_size(const struct ringbufindex *r);
+/* Return the number of elements currently in the ring buffer */
+int ringbufindex_elements(const struct ringbufindex *r);
+/* Is the ring buffer full? */
+int ringbufindex_full(const struct ringbufindex *r);
+/* Is the ring buffer empty? */
+int ringbufindex_empty(const struct ringbufindex *r);
+
+#endif /* __RINGBUFINDEX_H__ */