2 files changed, 8 insertions, 0 deletions
diff --git a/kernel/lib/ringbuffer.c b/kernel/lib/ringbuffer.c
index 425971d..66dd17e 100644
--- a/kernel/lib/ringbuffer.c
+++ b/kernel/lib/ringbuffer.c
@@ -65,6 +65,10 @@ u32 ringbuffer_read(struct ringbuffer *rb, u8 *buffer, u32 len) {
   return orig_len - len;
 }
 
+int ringbuffer_isempty(const struct ringbuffer *rb) {
+  return (rb->write_ptr == rb->read_ptr);
+}
+
 void ringbuffer_free(struct ringbuffer *rb) {
   kfree(rb->buffer);
   rb->buffer = NULL;
diff --git a/kernel/lib/ringbuffer.h b/kernel/lib/ringbuffer.h
index c329af3..3ebc507 100644
--- a/kernel/lib/ringbuffer.h
+++ b/kernel/lib/ringbuffer.h
@@ -1,3 +1,5 @@
+#ifndef RINGBUFFER_H
+#define RINGBUFFER_H
 #include <typedefs.h>
 
 struct ringbuffer {
@@ -10,7 +12,9 @@ struct ringbuffer {
 int ringbuffer_init(struct ringbuffer *rb, u32 buffer_size);
 u32 ringbuffer_write(struct ringbuffer *rb, const u8 *buffer, u32 len);
 u32 ringbuffer_read(struct ringbuffer *rb, u8 *buffer, u32 len);
+int ringbuffer_isempty(const struct ringbuffer *rb);
 void ringbuffer_free(struct ringbuffer *rb);
 #ifdef KERNEL_TEST
 void ringbuffer_test(void);
 #endif // KERNEL_TEST
+#endif // RINGBUFFER_H