1 files changed, 48 insertions, 0 deletions
diff --git a/kernel/include/mux/rbuffer.h b/kernel/include/mux/rbuffer.h
new file mode 100644
index 0000000..dceaeb0
--- /dev/null
+++ b/kernel/include/mux/rbuffer.h
@@ -0,0 +1,48 @@
+#ifndef RBUFFER_H
+#define RBUFFER_H
+
+#include <stddef.h>
+
+struct rbuffer_t {
+    char* address_begin;
+    char* address_end;
+    char* volatile head;
+    char* volatile tail;
+};
+
+#define RBUFFER_INIT(array, length) \
+    { \
+        .address_begin = array, \
+        .address_end = array + length, \
+        .head = array, \
+        .tail = array \
+    }
+
+#define INIT_RBUFFER(buffer, array, length) \
+    (buffer)->address_begin = (array); \
+    (buffer)->address_end = (array) + (length); \
+    (buffer)->head = (array); \
+    (buffer)->tail = (array)
+
+static inline int rbuffer_empty(struct rbuffer_t* const rb) {
+    return rb->head == rb->tail;
+}
+
+static inline int rbuffer_write(struct rbuffer_t* const rb, char data) {
+    char* next_head = rb->head + 1;
+    if(next_head >= rb->address_end) next_head = rb->address_begin;
+    if (rb->tail == next_head) return -1;
+    *rb->head = data;
+    rb->head = next_head;
+    return 0;
+}
+
+static inline int rbuffer_read(struct rbuffer_t* const rb, char* const data) {
+    if (rbuffer_empty(rb)) return -1;
+    *data = *rb->tail;
+    rb->tail += 1;
+    if(rb->tail >= rb->address_end) rb->tail = rb->address_begin;
+    return 0;
+}
+
+#endif