Make a new general RingBuffer.h misc library driver, instead of the per-application LightweightRingBuff.h ring buffers. Change over projects to use the new driver.

Add ORDERED_EP_CONFIG to the device Projects (only) that use only a single class driver, or where the endpoint ordering is fixed, to save on compiled binary size.

Added new GCC_FORCE_POINTER_ACCESS() macro to correct GCC's mishandling of struct pointers.

1 files changed, 254 insertions, 0 deletions

diff --git a/LUFA/Drivers/Misc/RingBuffer.h b/LUFA/Drivers/Misc/RingBuffer.h
new file mode 100644
index 000000000..30493e33a
--- /dev/null
+++ b/LUFA/Drivers/Misc/RingBuffer.h
@@ -0,0 +1,254 @@
+/*

+             LUFA Library

+     Copyright (C) Dean Camera, 2010.

+

+  dean [at] fourwalledcubicle [dot] com

+           www.lufa-lib.org

+*/

+

+/*

+  Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)

+

+  Permission to use, copy, modify, distribute, and sell this

+  software and its documentation for any purpose is hereby granted

+  without fee, provided that the above copyright notice appear in

+  all copies and that both that the copyright notice and this

+  permission notice and warranty disclaimer appear in supporting

+  documentation, and that the name of the author not be used in

+  advertising or publicity pertaining to distribution of the

+  software without specific, written prior permission.

+

+  The author disclaim all warranties with regard to this

+  software, including all implied warranties of merchantability

+  and fitness.  In no event shall the author be liable for any

+  special, indirect or consequential damages or any damages

+  whatsoever resulting from loss of use, data or profits, whether

+  in an action of contract, negligence or other tortious action,

+  arising out of or in connection with the use or performance of

+  this software.

+*/

+

+/** \file

+ *  \brief Lightweight ring buffer, for fast insertion/deletion.

+ *

+ *  Lightweight ring buffer, for fast insertion/deletion. Multiple buffers can be created of

+ *  different sizes to suit different needs.

+ *

+ *  Note that for each buffer, insertion and removal operations may occur at the same time (via

+ *  a multithreaded ISR based system) however the same kind of operation (two or more insertions

+ *  or deletions) must not overlap. If there is possibility of two or more of the same kind of

+ *  operating occuring at the same point in time, atomic (mutex) locking should be used.

+ */

+ 

+/** \ingroup Group_MiscDrivers

+ *  @defgroup Group_RingBuff Generic Byte Ring Buffer - LUFA/Drivers/Misc/RingBuffer.h

+ *

+ *  \section Sec_Dependencies Module Source Dependencies

+ *  The following files must be built with any user project that uses this module:

+ *    - None

+ *

+ *  \section Module Description

+ *  Lightweight ring buffer, for fast insertion/deletion. Multiple buffers can be created of

+ *  different sizes to suit different needs.

+ *

+ *  Note that for each buffer, insertion and removal operations may occur at the same time (via

+ *  a multithreaded ISR based system) however the same kind of operation (two or more insertions

+ *  or deletions) must not overlap. If there is possibility of two or more of the same kind of

+ *  operating occuring at the same point in time, atomic (mutex) locking should be used.

+ *

+ *  Example Usage:

+ *  \code

+ *      // Create the buffer structure and its underlying storage array

+ *      RingBuff_t Buffer;

+ *      uint8_t    BufferData[128];

+ *

+ *      // Initialise the buffer with the created storage array

+ *      RingBuffer_InitBuffer(&Buffer, BufferData, sizeof(BufferData));

+ *

+ *      // Insert some data into the buffer

+ *      RingBuffer_Insert(Buffer, 'H');

+ *      RingBuffer_Insert(Buffer, 'E');

+ *      RingBuffer_Insert(Buffer, 'L');

+ *      RingBuffer_Insert(Buffer, 'L');

+ *      RingBuffer_Insert(Buffer, 'O');

+ *

+ *      // Cache the number of stored bytes in the buffer

+ *      uint16_t BufferCount = RingBuffer_GetCount(&Buffer);

+ *

+ *      // Printer stored data length

+ *      printf("Buffer Length: %d, Buffer Data:\r\n", BufferCount);

+ *

+ *      // Print contents of the buffer one character at a time

+ *      while (BufferCount--)

+ *        putc(RingBuffer_Remove(&Buffer));

+ *  \endcode

+ *

+ *  @{

+ */

+

+#ifndef __RING_BUFF_H__

+#define __RING_BUFF_H__

+

+	/* Includes: */

+		#include <util/atomic.h>

+		#include <stdint.h>

+		#include <stdbool.h>

+

+		#include <LUFA/Common/Common.h>

+

+	/* Type Defines: */

+		/** Type define for a new ring buffer object. Buffers should be initialized via a call to

+		 *  \ref RingBuffer_InitBuffer() before use.

+		 */

+		typedef struct

+		{

+			uint8_t* In; /**< Current storage location in the circular buffer */

+			uint8_t* Out; /**< Current retrieval location in the circular buffer */

+			uint8_t* Start; /** Pointer to the start of the buffer's underlying storage array */

+			uint8_t* End; /** Pointer to the end of the buffer's underlying storage array */

+			uint8_t  Size; /** Size of the buffer's underlying storage array */

+			uint16_t Count; /** Number of bytes currently stored in the buffer */

+		} RingBuff_t;

+

+	/* Inline Functions: */

+		/** Initializes a ring buffer ready for use. Buffers must be initialized via this function

+		 *  before any operations are called upon them. Already initialized buffers may be reset

+		 *  by re-initializing them using this function.

+		 *

+		 *  \param[out] Buffer   Pointer to a ring buffer structure to initialize

+		 *  \param[out] DataPtr  Pointer to a global array that will hold the data stored into the ring buffer

+		 *  \param[out] Size     Maximum number of bytes that can be stored in the underlying data array

+		 */

+		static inline void RingBuffer_InitBuffer(RingBuff_t* Buffer, uint8_t* const DataPtr, const uint16_t Size)

+		{

+			ATOMIC_BLOCK(ATOMIC_RESTORESTATE)

+			{

+				GCC_FORCE_POINTER_ACCESS(Buffer);

+				

+				Buffer->In     = DataPtr;

+				Buffer->Out    = DataPtr;

+				Buffer->Start  = &DataPtr[0];

+				Buffer->End    = &DataPtr[Size];

+				Buffer->Size   = Size;

+				Buffer->Count  = 0;

+			}

+		}

+

+		/** Retrieves the minimum number of bytes stored in a particular buffer. This value is computed

+		 *  by entering an atomic lock on the buffer while the IN and OUT locations are fetched, so that

+		 *  the buffer cannot be modified while the computation takes place. This value should be cached

+		 *  when reading out the contents of the buffer, so that as small a time as possible is spent

+		 *  in an atomic lock.

+		 *

+		 *  \note The value returned by this function is guaranteed to only be the minimum number of bytes

+		 *        stored in the given buffer; this value may change as other threads write new data and so

+		 *        the returned number should be used only to determine how many successive reads may safely

+		 *        be performed on the buffer.

+		 *

+		 *  \param[in] Buffer  Pointer to a ring buffer structure whose count is to be computed

+		 */

+		static inline uint16_t RingBuffer_GetCount(RingBuff_t* const Buffer)

+		{

+			uint16_t Count;

+

+			ATOMIC_BLOCK(ATOMIC_RESTORESTATE)

+			{

+				Count = Buffer->Count;

+			}

+

+			return Count;

+		}

+

+		/** 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)

+		{

+			return (RingBuffer_GetCount(Buffer) == Buffer->Size);

+		}

+

+		/** Atomically determines if the specified ring buffer contains any data. This should

+		 *  be tested before removing data from the buffer, to ensure that the buffer does not

+		 *  underflow.

+		 *

+		 *  If the data is to be removed in a loop, store the total number of bytes stored in the

+		 *  buffer (via a call to the \ref RingBuffer_GetCount() function) in a temporary variable

+		 *  to reduce the time spent in atomicity locks.

+		 *

+		 *  \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_IsEmpty(RingBuff_t* const Buffer)

+		{

+			return (RingBuffer_GetCount(Buffer) == 0);

+		}

+

+		/** Inserts an element into the ring buffer.

+		 *

+		 *  \note Only one execution thread (main program thread or an ISR) may insert into a single buffer

+		 *        otherwise data corruption may occur. Insertion and removal may occur from different execution

+		 *        threads.

+		 *

+		 *  \param[in,out] Buffer  Pointer to a ring buffer structure to insert into

+		 *  \param[in]     Data    Data element to insert into the buffer

+		 */

+		static inline void RingBuffer_Insert(RingBuff_t* const Buffer,

+		                                     const uint8_t Data)

+		{

+			*Buffer->In = Data;

+

+			if (++Buffer->In == Buffer->End)

+			  Buffer->In = Buffer->Start;

+

+			ATOMIC_BLOCK(ATOMIC_RESTORESTATE)

+			{

+				Buffer->Count++;

+			}

+		}

+

+		/** Removes an element from the ring buffer.

+		 *

+		 *  \note Only one execution thread (main program thread or an ISR) may remove from a single buffer

+		 *        otherwise data corruption may occur. Insertion and removal may occur from different execution

+		 *        threads.

+		 *

+		 *  \param[in,out] Buffer  Pointer to a ring buffer structure to retrieve from

+		 *

+		 *  \return Next data element stored in the buffer

+		 */

+		static inline uint8_t RingBuffer_Remove(RingBuff_t* const Buffer)

+		{

+			uint8_t Data = *Buffer->Out;

+

+			if (++Buffer->Out == Buffer->End)

+			  Buffer->Out = Buffer->Start;

+

+			ATOMIC_BLOCK(ATOMIC_RESTORESTATE)

+			{

+				Buffer->Count--;

+			}

+

+			return Data;

+		}

+

+		/** Returns the next element stored in the ring buffer, without removing it.

+		 *

+		 *  \param[in,out] Buffer  Pointer to a ring buffer structure to retrieve from

+		 *

+		 *  \return Next data element stored in the buffer

+		 */

+		static inline uint8_t RingBuffer_Peek(RingBuff_t* const Buffer)

+		{

+			return *Buffer->Out;

+		}

+

+#endif

+

+/** @} */

+