1 files changed, 63 insertions, 0 deletions
diff --git a/include/rtems/ringbuf.h b/include/rtems/ringbuf.h
new file mode 100644
index 0000000000..c16a79d1ae
--- /dev/null
+++ b/include/rtems/ringbuf.h
@@ -0,0 +1,63 @@
+/**
+ * @file
+ *
+ * @brief Simple Ring Buffer Functionality
+ *
+ * This file provides simple ring buffer functionality.
+ */
+
+
+#ifndef _RTEMS_RINGBUF_H
+#define _RTEMS_RINGBUF_H
+
+#include <rtems.h>
+
+#ifndef RINGBUF_QUEUE_LENGTH
+#define RINGBUF_QUEUE_LENGTH 128
+#endif
+
+typedef struct {
+  uint8_t buffer[RINGBUF_QUEUE_LENGTH];
+  volatile int  head;
+  volatile int  tail;
+  rtems_interrupt_lock lock;
+} Ring_buffer_t;
+
+#define Ring_buffer_Initialize( _buffer ) \
+  do { \
+    (_buffer)->head = (_buffer)->tail = 0; \
+    rtems_interrupt_lock_initialize(&(_buffer)->lock, "ring buffer"); \
+  } while ( 0 )
+
+#define Ring_buffer_Destory( _buffer ) \
+  do { \
+    rtems_interrupt_lock_destroy(&(_buffer)->lock); \
+  } while ( 0 )
+
+#define Ring_buffer_Is_empty( _buffer ) \
+   ( (_buffer)->head == (_buffer)->tail )
+
+#define Ring_buffer_Is_full( _buffer ) \
+   ( (_buffer)->head == ((_buffer)->tail + 1) % RINGBUF_QUEUE_LENGTH )
+
+#define Ring_buffer_Add_character( _buffer, _ch ) \
+  do { \
+    rtems_interrupt_lock_context lock_context; \
+    \
+    rtems_interrupt_lock_acquire( &(_buffer)->lock, &lock_context ); \
+      (_buffer)->tail = ((_buffer)->tail+1) % RINGBUF_QUEUE_LENGTH; \
+      (_buffer)->buffer[ (_buffer)->tail ] = (_ch); \
+    rtems_interrupt_lock_release( &(_buffer)->lock, &lock_context ); \
+  } while ( 0 )
+
+#define Ring_buffer_Remove_character( _buffer, _ch ) \
+  do { \
+    rtems_interrupt_lock_context lock_context; \
+    \
+    rtems_interrupt_lock_acquire( &(_buffer)->lock, &lock_context ); \
+      (_buffer)->head = ((_buffer)->head+1) % RINGBUF_QUEUE_LENGTH; \
+      (_ch) = (_buffer)->buffer[ (_buffer)->head ]; \
+    rtems_interrupt_lock_release( &(_buffer)->lock, &lock_context ); \
+  } while ( 0 )
+
+#endif