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+/*
+ ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
+ 2011,2012,2013 Giovanni Di Sirio.
+
+ This file is part of ChibiOS/RT.
+
+ ChibiOS/RT 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/RT 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 chlists.c
+ * @brief Thread queues/lists code.
+ *
+ * @addtogroup internals
+ * @details All the functions present in this module, while public, are not
+ * OS APIs and should not be directly used in the user applications
+ * code.
+ * @{
+ */
+#include "ch.h"
+
+/*===========================================================================*/
+/* Module local definitions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module exported variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local variables. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module local functions. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module exported functions. */
+/*===========================================================================*/
+
+#if !CH_CFG_OPTIMIZE_SPEED || defined(__DOXYGEN__)
+/**
+ * @brief Inserts a thread into a priority ordered queue.
+ * @note The insertion is done by scanning the list from the highest
+ * priority toward the lowest.
+ *
+ * @param[in] tp the pointer to the thread to be inserted in the list
+ * @param[in] tqp the pointer to the threads list header
+ *
+ * @notapi
+ */
+void queue_prio_insert(thread_t *tp, threads_queue_t *tqp) {
+
+ /* cp iterates over the queue.*/
+ thread_t *cp = (thread_t *)tqp;
+ do {
+ /* Iterate to next thread in queue.*/
+ cp = cp->p_next;
+ /* Not end of queue? and cp has equal or higher priority than tp?.*/
+ } while ((cp != (thread_t *)tqp) && (cp->p_prio >= tp->p_prio));
+ /* Insertion on p_prev.*/
+ tp->p_next = cp;
+ tp->p_prev = cp->p_prev;
+ tp->p_prev->p_next = cp->p_prev = tp;
+}
+
+/**
+ * @brief Inserts a thread into a queue.
+ *
+ * @param[in] tp the pointer to the thread to be inserted in the list
+ * @param[in] tqp the pointer to the threads list header
+ *
+ * @notapi
+ */
+void queue_insert(thread_t *tp, threads_queue_t *tqp) {
+
+ tp->p_next = (thread_t *)tqp;
+ tp->p_prev = tqp->p_prev;
+ tp->p_prev->p_next = tqp->p_prev = tp;
+}
+
+/**
+ * @brief Removes the first-out thread from a queue and returns it.
+ * @note If the queue is priority ordered then this function returns the
+ * thread with the highest priority.
+ *
+ * @param[in] tqp the pointer to the threads list header
+ * @return The removed thread pointer.
+ *
+ * @notapi
+ */
+thread_t *queue_fifo_remove(threads_queue_t *tqp) {
+ thread_t *tp = tqp->p_next;
+
+ (tqp->p_next = tp->p_next)->p_prev = (thread_t *)tqp;
+ return tp;
+}
+
+/**
+ * @brief Removes the last-out thread from a queue and returns it.
+ * @note If the queue is priority ordered then this function returns the
+ * thread with the lowest priority.
+ *
+ * @param[in] tqp the pointer to the threads list header
+ * @return The removed thread pointer.
+ *
+ * @notapi
+ */
+thread_t *queue_lifo_remove(threads_queue_t *tqp) {
+ thread_t *tp = tqp->p_prev;
+
+ (tqp->p_prev = tp->p_prev)->p_next = (thread_t *)tqp;
+ return tp;
+}
+
+/**
+ * @brief Removes a thread from a queue and returns it.
+ * @details The thread is removed from the queue regardless of its relative
+ * position and regardless the used insertion method.
+ *
+ * @param[in] tp the pointer to the thread to be removed from the queue
+ * @return The removed thread pointer.
+ *
+ * @notapi
+ */
+thread_t *queue_dequeue(thread_t *tp) {
+
+ tp->p_prev->p_next = tp->p_next;
+ tp->p_next->p_prev = tp->p_prev;
+ return tp;
+}
+
+/**
+ * @brief Pushes a thread_t on top of a stack list.
+ *
+ * @param[in] tp the pointer to the thread to be inserted in the list
+ * @param[in] tlp the pointer to the threads list header
+ *
+ * @notapi
+ */
+void list_insert(thread_t *tp, threads_list_t *tlp) {
+
+ tp->p_next = tlp->p_next;
+ tlp->p_next = tp;
+}
+
+/**
+ * @brief Pops a thread from the top of a stack list and returns it.
+ * @pre The list must be non-empty before calling this function.
+ *
+ * @param[in] tlp the pointer to the threads list header
+ * @return The removed thread pointer.
+ *
+ * @notapi
+ */
+thread_t *list_remove(threads_list_t *tlp) {
+
+ thread_t *tp = tlp->p_next;
+ tlp->p_next = tp->p_next;
+ return tp;
+}
+#endif /* CH_CFG_OPTIMIZE_SPEED */
+
+/** @} */