Added some volatile keywords to make it interrupt safe.

bacnet-stack/include/ringbuf.h

@@ -43,11 +43,11 @@
 #include <stdbool.h>
 
 struct ring_buffer_t {
-    uint8_t *data;      /* block of memory or array of data */
+    uint8_t * volatile buffer; /* block of memory or array of data */
     unsigned element_size;      /* how many bytes for each chunk */
     unsigned element_count;     /* number of chunks of data */
-    unsigned head;      /* where the writes go */
-    unsigned tail;      /* where the reads come from */
+    volatile unsigned head;      /* where the writes go */
+    volatile unsigned tail;      /* where the reads come from */
 };
 typedef struct ring_buffer_t RING_BUFFER;
 
@@ -73,7 +73,7 @@ extern "C" {
     /* Note: element_count must be a power of two */
     void Ringbuf_Init(
         RING_BUFFER * b,        /* ring buffer structure */
-        uint8_t * data, /* data block or array of data */
+        uint8_t * volatile buffer,     /* data block or array of data */
         unsigned element_size,  /* size of one element in the data block */
         unsigned element_count);        /* number of elements in the data block */