Fixed possible buffer overrun in the XPLAINBridge project when in serial bridge mode.

[pub/USBasp.git] / Projects / XPLAINBridge / Lib / LightweightRingBuff.h

diff --git a/Projects/XPLAINBridge/Lib/LightweightRingBuff.h b/Projects/XPLAINBridge/Lib/LightweightRingBuff.h
index 9c25707..0ffe792 100644 (file)
--- a/Projects/XPLAINBridge/Lib/LightweightRingBuff.h
+++ b/Projects/XPLAINBridge/Lib/LightweightRingBuff.h
@@ -75,6 +75,26 @@
                        Buffer->Count = 0;
                }
                
+               /** Atomically determines if the specified ring buffer contains any free space. This should
+                *  be tested before storing data to the buffer, to ensure that no data is lost due to a
+                *  buffer overrun.
+                *
+                *  \param[in,out] Buffer  Pointer to a ring buffer structure to insert into
+                *
+                *  \return Boolean true if the buffer contains no free space, false otherwise
+                */              
+               static inline bool RingBuffer_IsFull(RingBuff_t* const Buffer)
+               {
+                       bool IsFull;
+                       
+                       ATOMIC_BLOCK(ATOMIC_RESTORESTATE)
+                       {
+                               IsFull = (Buffer->Count == BUFFER_SIZE);
+                       }
+                       
+                       return IsFull;
+               }
+               
                /** Atomically inserts an element into the ring buffer.
                 *
                 *  \param[in,out] Buffer  Pointer to a ring buffer structure to insert into