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Diffstat (limited to 'os/rt/include/chschd.h')
| -rw-r--r-- | os/rt/include/chschd.h | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/os/rt/include/chschd.h b/os/rt/include/chschd.h new file mode 100644 index 000000000..248f707c8 --- /dev/null +++ b/os/rt/include/chschd.h @@ -0,0 +1,218 @@ +/*
+ 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 chschd.h
+ * @brief Scheduler macros and structures.
+ *
+ * @addtogroup scheduler
+ * @{
+ */
+
+#ifndef _CHSCHD_H_
+#define _CHSCHD_H_
+
+/*===========================================================================*/
+/* Module constants. */
+/*===========================================================================*/
+
+/**
+ * @name Wakeup status codes
+ * @{
+ */
+#define RDY_OK 0 /**< @brief Normal wakeup message. */
+#define RDY_TIMEOUT -1 /**< @brief Wakeup caused by a timeout
+ condition. */
+#define RDY_RESET -2 /**< @brief Wakeup caused by a reset
+ condition. */
+/** @} */
+
+/**
+ * @name Priority constants
+ * @{
+ */
+#define NOPRIO 0 /**< @brief Ready list header priority. */
+#define IDLEPRIO 1 /**< @brief Idle thread priority. */
+#define LOWPRIO 2 /**< @brief Lowest user priority. */
+#define NORMALPRIO 64 /**< @brief Normal user priority. */
+#define HIGHPRIO 127 /**< @brief Highest user priority. */
+#define ABSPRIO 255 /**< @brief Greatest possible priority. */
+/** @} */
+
+/**
+ * @name Special time constants
+ * @{
+ */
+/**
+ * @brief Zero time specification for some functions with a timeout
+ * specification.
+ * @note Not all functions accept @p TIME_IMMEDIATE as timeout parameter,
+ * see the specific function documentation.
+ */
+#define TIME_IMMEDIATE ((systime_t)0)
+
+/**
+ * @brief Infinite time specification for all functions with a timeout
+ * specification.
+ */
+#define TIME_INFINITE ((systime_t)-1)
+/** @} */
+
+/*===========================================================================*/
+/* Module pre-compile time settings. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Derived constants and error checks. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module data structures and types. */
+/*===========================================================================*/
+
+/*===========================================================================*/
+/* Module macros. */
+/*===========================================================================*/
+
+/**
+ * @brief Returns the priority of the first thread on the given ready list.
+ *
+ * @notapi
+ */
+#define firstprio(rlp) ((rlp)->p_next->p_prio)
+
+/**
+ * @brief Current thread pointer access macro.
+ * @note This macro is not meant to be used in the application code but
+ * only from within the kernel, use the @p chThdSelf() API instead.
+ * @note It is forbidden to use this macro in order to change the pointer
+ * (currp = something), use @p setcurrp() instead.
+ */
+#define currp ch.rlist.r_current
+
+/**
+ * @brief Current thread pointer change macro.
+ * @note This macro is not meant to be used in the application code but
+ * only from within the kernel.
+ *
+ * @notapi
+ */
+#define setcurrp(tp) (currp = (tp))
+
+/*===========================================================================*/
+/* External declarations. */
+/*===========================================================================*/
+
+/*
+ * Scheduler APIs.
+ */
+#ifdef __cplusplus
+extern "C" {
+#endif
+ void _scheduler_init(void);
+ thread_t *chSchReadyI(thread_t *tp);
+ void chSchGoSleepS(tstate_t newstate);
+ msg_t chSchGoSleepTimeoutS(tstate_t newstate, systime_t time);
+ void chSchWakeupS(thread_t *tp, msg_t msg);
+ void chSchRescheduleS(void);
+ bool chSchIsPreemptionRequired(void);
+ void chSchDoRescheduleBehind(void);
+ void chSchDoRescheduleAhead(void);
+ void chSchDoReschedule(void);
+#ifdef __cplusplus
+}
+#endif
+
+/*===========================================================================*/
+/* Module inline functions. */
+/*===========================================================================*/
+
+/**
+ * @brief Determines if the current thread must reschedule.
+ * @details This function returns @p true if there is a ready thread with
+ * higher priority.
+ *
+ * @iclass
+ */
+static inline bool chSchIsRescRequiredI(void) {
+
+ chDbgCheckClassI();
+
+ return firstprio(&ch.rlist.r_queue) > currp->p_prio;
+}
+
+/**
+ * @brief Determines if yielding is possible.
+ * @details This function returns @p true if there is a ready thread with
+ * equal or higher priority.
+ *
+ * @sclass
+ */
+static inline bool chSchCanYieldS(void) {
+
+ chDbgCheckClassI();
+
+ return firstprio(&ch.rlist.r_queue) >= currp->p_prio;
+}
+
+/**
+ * @brief Yields the time slot.
+ * @details Yields the CPU control to the next thread in the ready list with
+ * equal or higher priority, if any.
+ *
+ * @sclass
+ */
+static inline void chSchDoYieldS(void) {
+
+ chDbgCheckClassS();
+
+ if (chSchCanYieldS())
+ chSchDoRescheduleBehind();
+}
+
+/**
+ * @brief Inline-able preemption code.
+ * @details This is the common preemption code, this function must be invoked
+ * exclusively from the port layer.
+ *
+ * @special
+ */
+static inline void chSchPreemption(void) {
+ tprio_t p1 = firstprio(&ch.rlist.r_queue);
+ tprio_t p2 = currp->p_prio;
+
+#if CH_CFG_TIME_QUANTUM > 0
+ if (currp->p_preempt) {
+ if (p1 > p2)
+ chSchDoRescheduleAhead();
+ }
+ else {
+ if (p1 >= p2)
+ chSchDoRescheduleBehind();
+ }
+#else /* CH_CFG_TIME_QUANTUM == 0 */
+ if (p1 >= p2)
+ chSchDoRescheduleAhead();
+#endif /* CH_CFG_TIME_QUANTUM == 0 */
+}
+
+#endif /* _CHSCHD_H_ */
+
+/** @} */
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