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Diffstat (limited to 'os/kernel/src/chvt.c')
| -rw-r--r-- | os/kernel/src/chvt.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/os/kernel/src/chvt.c b/os/kernel/src/chvt.c new file mode 100644 index 000000000..a8e3ce499 --- /dev/null +++ b/os/kernel/src/chvt.c @@ -0,0 +1,134 @@ +/*
+ 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 chvt.c
+ * @brief Time and Virtual Timers related code.
+ *
+ * @addtogroup time
+ * @details Time and Virtual Timers related APIs and services.
+ * @{
+ */
+
+#include "ch.h"
+
+/**
+ * @brief Virtual timers delta list header.
+ */
+VTList vtlist;
+
+/**
+ * @brief Virtual Timers initialization.
+ * @note Internal use only.
+ *
+ * @notapi
+ */
+void _vt_init(void) {
+
+ vtlist.vt_next = vtlist.vt_prev = (void *)&vtlist;
+ vtlist.vt_time = (systime_t)-1;
+ vtlist.vt_systime = 0;
+}
+
+/**
+ * @brief Enables a virtual timer.
+ * @note The associated function is invoked from interrupt context.
+ *
+ * @param[out] vtp the @p VirtualTimer structure pointer
+ * @param[in] time the number of ticks before the operation timeouts, the
+ * special values are handled as follow:
+ * - @a TIME_INFINITE is allowed but interpreted as a
+ * normal time specification.
+ * - @a TIME_IMMEDIATE this value is not allowed.
+ * .
+ * @param[in] vtfunc the timer callback function. After invoking the
+ * callback the timer is disabled and the structure can
+ * be disposed or reused.
+ * @param[in] par a parameter that will be passed to the callback
+ * function
+ *
+ * @iclass
+ */
+void chVTSetI(VirtualTimer *vtp, systime_t time, vtfunc_t vtfunc, void *par) {
+ VirtualTimer *p;
+
+ chDbgCheckClassI();
+ chDbgCheck((vtp != NULL) && (vtfunc != NULL) && (time != TIME_IMMEDIATE),
+ "chVTSetI");
+
+ vtp->vt_par = par;
+ vtp->vt_func = vtfunc;
+ p = vtlist.vt_next;
+ while (p->vt_time < time) {
+ time -= p->vt_time;
+ p = p->vt_next;
+ }
+
+ vtp->vt_prev = (vtp->vt_next = p)->vt_prev;
+ vtp->vt_prev->vt_next = p->vt_prev = vtp;
+ vtp->vt_time = time;
+ if (p != (void *)&vtlist)
+ p->vt_time -= time;
+}
+
+/**
+ * @brief Disables a Virtual Timer.
+ * @note The timer MUST be active when this function is invoked.
+ *
+ * @param[in] vtp the @p VirtualTimer structure pointer
+ *
+ * @iclass
+ */
+void chVTResetI(VirtualTimer *vtp) {
+
+ chDbgCheckClassI();
+ chDbgCheck(vtp != NULL, "chVTResetI");
+ chDbgAssert(vtp->vt_func != NULL,
+ "chVTResetI(), #1",
+ "timer not set or already triggered");
+
+ if (vtp->vt_next != (void *)&vtlist)
+ vtp->vt_next->vt_time += vtp->vt_time;
+ vtp->vt_prev->vt_next = vtp->vt_next;
+ vtp->vt_next->vt_prev = vtp->vt_prev;
+ vtp->vt_func = (vtfunc_t)NULL;
+}
+
+/**
+ * @brief Checks if the current system time is within the specified time
+ * window.
+ * @note When start==end then the function returns always true because the
+ * whole time range is specified.
+ *
+ * @param[in] start the start of the time window (inclusive)
+ * @param[in] end the end of the time window (non inclusive)
+ * @retval TRUE current time within the specified time window.
+ * @retval FALSE current time not within the specified time window.
+ *
+ * @api
+ */
+bool_t chTimeIsWithin(systime_t start, systime_t end) {
+
+ systime_t time = chTimeNow();
+ return end > start ? (time >= start) && (time < end) :
+ (time >= start) || (time < end);
+}
+
+/** @} */
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