Pipes prototype, not complete.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@11801 110e8d01-0319-4d1e-a829-52ad28d1bb01

1 files changed, 210 insertions, 0 deletions

diff --git a/os/lib/include/chpipes.h b/os/lib/include/chpipes.h
new file mode 100644
index 000000000..197aa9199
--- /dev/null
+++ b/os/lib/include/chpipes.h
@@ -0,0 +1,210 @@
+/*
+    ChibiOS - Copyright (C) 2006..2018 Giovanni Di Sirio.
+
+    This file is part of ChibiOS.
+
+    ChibiOS is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    ChibiOS is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file    chpipes.h
+ * @brief   Pipes macros and structures.
+ *
+ * @addtogroup pipes
+ * @{
+ */
+
+#ifndef CHPIPES_H
+#define CHPIPES_H
+
+#if (CH_CFG_USE_PIPES == TRUE) || defined(__DOXYGEN__)
+
+/*===========================================================================*/
+/* Module constants.                                                         */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module pre-compile time settings.                                         */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Derived constants and error checks.                                       */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module data structures and types.                                         */
+/*===========================================================================*/
+
+/**
+ * @brief   Structure representing a pipe object.
+ */
+typedef struct {
+  uint8_t               *buffer;        /**< @brief Pointer to the pipe
+                                                    buffer.                 */
+  uint8_t               *top;           /**< @brief Pointer to the location
+                                                    after the buffer.       */
+  uint8_t               *wrptr;         /**< @brief Write pointer.          */
+  uint8_t               *rdptr;         /**< @brief Read pointer.           */
+  size_t                cnt;            /**< @brief Messages in queue.      */
+  bool                  reset;          /**< @brief True if in reset state. */
+  threads_queue_t       qw;             /**< @brief Queued writers.         */
+  threads_queue_t       qr;             /**< @brief Queued readers.         */
+} pipe_t;
+
+/*===========================================================================*/
+/* Module macros.                                                            */
+/*===========================================================================*/
+
+/**
+ * @brief   Data part of a static pipe initializer.
+ * @details This macro should be used when statically initializing a
+ *          pipe that is part of a bigger structure.
+ *
+ * @param[in] name      the name of the pipe variable
+ * @param[in] buffer    pointer to the pipe buffer array of @p uint8_t
+ * @param[in] size      number of @p uint8_t elements in the buffer array
+ */
+#define _PIPE_DATA(name, buffer, size) {                                    \
+  (uint8_t *)(buffer),                                                      \
+  (uint8_t *)(buffer) + size,                                               \
+  (uint8_t *)(buffer),                                                      \
+  (uint8_t *)(buffer),                                                      \
+  (size_t)0,                                                                \
+  false,                                                                    \
+  _THREADS_QUEUE_DATA(name.qw),                                             \
+  _THREADS_QUEUE_DATA(name.qr),                                             \
+}
+
+/**
+ * @brief   Static pipe initializer.
+ * @details Statically initialized pipes require no explicit
+ *          initialization using @p chPipeObjectInit().
+ *
+ * @param[in] name      the name of the pipe variable
+ * @param[in] buffer    pointer to the pipe buffer array of @p uint8_t
+ * @param[in] size      number of @p uint8_t elements in the buffer array
+ */
+#define PIPE_DECL(name, buffer, size)                                       \
+  pipe_t name = _PIPE_DATA(name, buffer, size)
+
+/*===========================================================================*/
+/* External declarations.                                                    */
+/*===========================================================================*/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+  void chPipeObjectInit(pipe_t *pp, uint8_t *buf, size_t n);
+  void chPipeReset(pipe_t *pp);
+  void chPipeResetI(pipe_t *pp);
+  size_t chPipeReadI(pipe_t *pp, uint8_t *bp, size_t n);
+  size_t chPipeReadTimeoutS(pipe_t *pp, uint8_t *bp,
+                            size_t n, sysinterval_t timeout);
+  size_t chPipeReadTimeout(pipe_t *pp, uint8_t *bp,
+                           size_t n, sysinterval_t timeout);
+  size_t chPipeWriteI(pipe_t *pp, const uint8_t *bp, size_t n);
+  size_t chPipeWriteTimeoutS(pipe_t *pp, const uint8_t *bp,
+                             size_t n, sysinterval_t timeout);
+  size_t chPipeWriteTimeout(pipe_t *pp, const uint8_t *bp,
+                            size_t n, sysinterval_t timeout);
+#ifdef __cplusplus
+}
+#endif
+
+/*===========================================================================*/
+/* Module inline functions.                                                  */
+/*===========================================================================*/
+
+/**
+ * @brief   Returns the pipe buffer size as number of bytes.
+ *
+ * @param[in] pp        the pointer to an initialized @p pipe_t object
+ * @return              The size of the pipe.
+ *
+ * @iclass
+ */
+static inline size_t chPipeGetSizeI(const pipe_t *pp) {
+
+  /*lint -save -e9033 [10.8] Perfectly safe pointers
+    arithmetic.*/
+  return (size_t)(pp->top - pp->buffer);
+  /*lint -restore*/
+}
+
+/**
+ * @brief   Returns the number of used byte slots into a pipe.
+ *
+ * @param[in] pp        the pointer to an initialized @p pipe_t object
+ * @return              The number of queued bytes.
+ *
+ * @iclass
+ */
+static inline size_t chPipeGetUsedCountI(const pipe_t *pp) {
+
+  chDbgCheckClassI();
+
+  return pp->cnt;
+}
+
+/**
+ * @brief   Returns the number of free byte slots into a pipe.
+ *
+ * @param[in] pp        the pointer to an initialized @p pipe_t object
+ * @return              The number of empty byte slots.
+ *
+ * @iclass
+ */
+static inline size_t chPipeGetFreeCountI(const pipe_t *pp) {
+
+  chDbgCheckClassI();
+
+  return chPipeGetSizeI(pp) - chPipeGetUsedCountI(pp);
+}
+
+/**
+ * @brief   Returns the next byte in the queue without removing it.
+ * @pre     A byte must be present in the queue for this function to work
+ *          or it would return garbage. The correct way to use this macro is
+ *          to use @p chPipeGetFullCountI() and then use this macro, all within
+ *          a lock state.
+ *
+ * @param[in] pp        the pointer to an initialized @p pipe_t object
+ * @return              The next byte in queue.
+ *
+ * @iclass
+ */
+static inline uint8_t chPipePeekI(const pipe_t *pp) {
+
+  chDbgCheckClassI();
+
+  return *pp->rdptr;
+}
+
+/**
+ * @brief   Terminates the reset state.
+ *
+ * @param[in] pp        the pointer to an initialized @p pipe_t object
+ *
+ * @xclass
+ */
+static inline void chPipeResumeX(pipe_t *pp) {
+
+  pp->reset = false;
+}
+
+#endif /* CH_CFG_USE_PIPES == TRUE */
+
+#endif /* CHPIPES_H */
+
+/** @} */