1 files changed, 214 insertions, 0 deletions

diff --git a/lib/chibios-contrib/os/various/tribuf.c b/lib/chibios-contrib/os/various/tribuf.c
new file mode 100644
index 000000000..6ba78d312
--- /dev/null
+++ b/lib/chibios-contrib/os/various/tribuf.c
@@ -0,0 +1,214 @@
+/*
+    Copyright (C) 2014..2015 Andrea Zoppi
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+*/
+
+#include "osal.h"
+#include "tribuf.h"
+
+/**
+ * @file    tribuf.c
+ * @brief   Triple buffer handler source.
+ *
+ * @addtogroup TriBuf
+ * @{
+ */
+
+/*===========================================================================*/
+/* Driver local definitions.                                                 */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported variables.                                                */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local variables and types.                                         */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver local functions.                                                   */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver interrupt handlers.                                                */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Driver exported functions.                                                */
+/*===========================================================================*/
+
+/**
+ * @brief   Initializes the tribuf handler object.
+ *
+ * @param[in] handler Pointer to the tribuf handler object.
+ * @param[in] front   Pointer to the initial front buffer.
+ * @param[in] back    Pointer to the initial back buffer.
+ * @param[in] orphan  Pointer to the initial orphan buffer.
+ *
+ * @init
+ */
+void tribufObjectInit(tribuf_t *handler, void *front, void *back, void *orphan) {
+
+  handler->front = front;
+  handler->back = back;
+  handler->orphan = orphan;
+#if (TRIBUF_USE_WAIT == TRUE)
+  chSemObjectInit(&handler->ready, (cnt_t)0);
+#else
+  handler->ready = false;
+#endif
+}
+
+/**
+ * @brief   Gets the current front buffer.
+ *
+ * @param[in] handler   Pointer to the tribuf handler object.
+ * @return  Pointer to the current front buffer.
+ *
+ * @api
+ */
+void *tribufGetFront(tribuf_t *handler) {
+
+  void *front;
+
+  osalSysLock();
+  front = tribufGetFrontI(handler);
+  osalSysUnlock();
+  return front;
+}
+
+/**
+ * @brief   Swaps the current front buffer.
+ *
+ * @details Exchanges the pointer of the current front buffer, which will be
+ *          dismissed, with the pointer of the current orphan buffer, which
+ *          holds the content of the new front buffer.
+ *
+ * @pre   The orphan buffer holds new data, swapped by the back buffer.
+ * @pre   The fron buffer is ready for swap.
+ * @post  The orphan buffer can be used as new back buffer in the future.
+ *
+ * @param[in] handler   Pointer to the tribuf handler object.
+ *
+ * @iclass
+ */
+void tribufSwapFrontI(tribuf_t *handler) {
+
+  void *front;
+
+  osalDbgCheckClassI();
+
+  front = handler->orphan;
+  handler->orphan = handler->front;
+  handler->front = front;
+}
+
+/**
+ * @brief   Swaps the current front buffer.
+ *
+ * @details Exchanges the pointer of the current front buffer, which will be
+ *          dismissed, with the pointer of the current orphan buffer, which
+ *          holds the content of the new front buffer.
+ *
+ * @pre   The orphan buffer holds new data, swapped by the back buffer.
+ * @pre   The fron buffer is ready for swap.
+ * @post  The orphan buffer can be used as new back buffer in the future.
+ *
+ * @param[in] handler   Pointer to the tribuf handler object.
+ *
+ * @api
+ */
+void tribufSwapFront(tribuf_t *handler) {
+
+  osalSysLock();
+  tribufSwapFrontI(handler);
+  osalSysUnlock();
+}
+
+/**
+ * @brief   Gets the current back buffer.
+ *
+ * @param[in] handler   Pointer to the tribuf handler object.
+ * @return Pointer to the current back buffer.
+ *
+ * @api
+ */
+void *tribufGetBack(tribuf_t *handler) {
+
+  void *back;
+
+  osalSysLock();
+  back = tribufGetBackI(handler);
+  osalSysUnlock();
+  return back;
+}
+
+/**
+ * @brief   Swaps the current back buffer.
+ *
+ * @details Exchanges the pointer of the current back buffer, which holds new
+ *          useful data, with the pointer of the current orphan buffer.
+ *
+ * @pre   The orphan buffer holds no meaningful data.
+ * @post  The orphan buffer is candidate for new front buffer.
+ * @post  A new front buffer is ready and signaled.
+ *
+ * @param[in] handler   Pointer to the tribuf handler object.
+ *
+ * @iclass
+ */
+void tribufSwapBackI(tribuf_t *handler) {
+
+  void *back;
+
+  osalDbgCheckClassI();
+
+  back = handler->orphan;
+  handler->orphan = handler->back;
+  handler->back = back;
+
+#if (TRIBUF_USE_WAIT == TRUE)
+  if (chSemGetCounterI(&handler->ready) < (cnt_t)1)
+    chSemSignalI(&handler->ready);
+#else
+  handler->ready = true;
+#endif
+}
+
+/**
+ * @brief   Swaps the current back buffer.
+ *
+ * @details Exchanges the pointer of the current back buffer, which holds new
+ *          useful data, with the pointer of the current orphan buffer.
+ *
+ * @pre   The orphan buffer holds no meaningful data.
+ * @post  The orphan buffer is candidate for new front buffer.
+ * @post  A new front buffer is ready and signaled.
+ *
+ * @param[in] handler   Pointer to the tribuf handler object.
+ *
+ * @api
+ */
+void tribufSwapBack(tribuf_t *handler) {
+
+  osalSysLock();
+  tribufSwapBackI(handler);
+#if (TRIBUF_USE_WAIT == TRUE)
+  osalOsRescheduleS();
+#endif
+  osalSysUnlock();
+}
+
+/** @} */