Added FIFO library code.

bacnet-stack/include/fifo.h

@@ -0,0 +1,82 @@
+/*####COPYRIGHTBEGIN####
+ -------------------------------------------
+ Copyright (C) 2008 by Steve Karg
+
+ This program is free software; you can redistribute it and/or
+ modify it under the terms of the GNU General Public License
+ as published by the Free Software Foundation; either version 2
+ of the License, or (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to:
+ The Free Software Foundation, Inc.
+ 59 Temple Place - Suite 330
+ Boston, MA  02111-1307
+ USA.
+
+ As a special exception, if other files instantiate templates or
+ use macros or inline functions from this file, or you compile
+ this file and link it with other works to produce a work based
+ on this file, this file does not by itself cause the resulting
+ work to be covered by the GNU General Public License. However
+ the source code for this file must still be made available in
+ accordance with section (3) of the GNU General Public License.
+
+ This exception does not invalidate any other reasons why a work
+ based on this file might be covered by the GNU General Public
+ License.
+ -------------------------------------------
+####COPYRIGHTEND####*/
+
+/* Functional Description: Generic FIFO library for deeply
+   embedded system. See the unit tests for usage examples.
+   This library only uses a byte sized chunk.
+   This library is designed for use in Interrupt Service Routines
+   and so is declared as "static inline" */
+
+#ifndef FIFO_H
+#define FIFO_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+struct fifo_buffer_t {
+    volatile unsigned head;      /* first byte of data */
+    volatile unsigned tail;     /* last byte of data */
+    volatile uint8_t *buffer; /* block of memory or array of data */
+    unsigned buffer_len;     /* length of the data */
+};
+typedef struct fifo_buffer_t FIFO_BUFFER;
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+bool FIFO_Empty(
+        FIFO_BUFFER const *b);
+
+uint8_t FIFO_Peek(
+        FIFO_BUFFER const *b);
+
+uint8_t FIFO_Get(
+        FIFO_BUFFER * b);
+
+bool FIFO_Put(
+        FIFO_BUFFER * b,
+        uint8_t data_byte);
+
+/* note: buffer_len must be a power of two */
+void FIFO_Init(
+        FIFO_BUFFER * b,
+        volatile uint8_t *buffer,
+        unsigned buffer_len);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif