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Diffstat (limited to 'src/chcond.c')
| -rw-r--r-- | src/chcond.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/chcond.c b/src/chcond.c new file mode 100644 index 000000000..27e746d39 --- /dev/null +++ b/src/chcond.c @@ -0,0 +1,216 @@ +/*
+ ChibiOS/RT - Copyright (C) 2006-2007 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/>.
+*/
+/*
+ Concepts and parts of this file are contributed by and Copyright (C) 2008
+ of Leon Woestenberg
+ */
+
+/**
+ * @addtogroup CondVars
+ * @{
+ */
+
+#include <ch.h>
+
+#if defined(CH_USE_CONDVARS) && defined(CH_USE_MUTEXES)
+
+/**
+ * Initializes s \p CondVar structure.
+ * @param cp pointer to a \p CondVar structure
+ */
+void chCondInit(CondVar *cp) {
+
+ queue_init(&cp->c_queue);
+}
+
+/**
+ * Signals one thread that is waiting on the condition variable.
+ *
+ * @param mp pointer to the \p CondVar structure
+ */
+void chCondSignal(CondVar *cp) {
+
+ chSysLock();
+
+ if (notempty(&cp->c_queue)) /* any thread ? */
+ chSchWakeupS(fifo_remove(&cp->c_queue), RDY_OK);
+
+ chSysUnlock();
+}
+
+/**
+ * Signals one thread that is waiting on the condition variable.
+ *
+ * @param cp pointer to the \p CondVar structure
+ * @note This function must be called within a \p chSysLock() / \p chSysUnlock()
+ * block.
+ */
+void chCondSignalI(CondVar *cp) {
+
+ if (notempty(&cp->c_queue)) /* any thread ? */
+ chSchReadyI(fifo_remove(&cp->c_queue))->p_rdymsg = RDY_OK;
+}
+
+/**
+ * Signal all threads that are waiting on the condition variable.
+ *
+ * @param mp pointer to the \p CondVar structure
+ */
+void chCondBroadcast(CondVar *cp) {
+
+ chSysLock();
+
+ chCondBroadcastI(cp);
+ chSchRescheduleS();
+
+ chSysUnlock();
+}
+
+/**
+ * Signal all threads that are waiting on the condition variable.
+ *
+ * @param cp pointer to the \p CondVar structure
+ * @note This function must be called within a \p chSysLock() / \p chSysUnlock()
+ */
+void chCondBroadcastI(CondVar *cp) {
+
+ /* empties the condition variable queue and inserts all the Threads into the
+ * ready list in FIFO order. The wakeup message is set to \p RDY_RESET in
+ * order to make a chCondBroadcast() detectable from a chCondSignal(). */
+ while (cp->c_queue.p_next != (void *)&cp->c_queue)
+ chSchReadyI(fifo_remove(&cp->c_queue))->p_rdymsg = RDY_RESET;
+}
+
+/**
+ * Wait on the condition variable releasing the mutex lock.
+ *
+ * Releases the mutex, waits on the condition variable, and finally acquires
+ * the mutex again. This is done atomically.
+ *
+ * The thread MUST already have locked the mutex when calling chCondWait().
+ *
+ * @param cp pointer to the \p CondVar structure
+ * @return The wakep mode.
+ * @retval RDY_OK if the condvar was signaled using chCondSignal().
+ * @retval RDY_RESET if the condvar was signaled using chCondBroadcast().
+ */
+msg_t chCondWait(CondVar *cp) {
+ msg_t msg;
+
+ chSysLock();
+
+ msg = chCondWaitS(cp);
+
+ chSysUnlock();
+ return msg;
+}
+
+/**
+ * Wait on the condition variable releasing the mutex lock.
+ *
+ * Releases the mutex, waits on the condition variable, and finally acquires
+ * the mutex again. This is done atomically.
+ *
+ * The thread MUST already have locked the mutex when calling chCondWait().
+ *
+ * @param cp pointer to the \p CondVar structure
+ * @return The wakep mode.
+ * @retval RDY_OK if the condvar was signaled using chCondSignal().
+ * @retval RDY_RESET if the condvar was signaled using chCondBroadcast().
+ * @note This function must be called within a \p chSysLock() / \p chSysUnlock()
+ */
+msg_t chCondWaitS(CondVar *cp) {
+ Mutex *mp;
+ msg_t msg;
+
+ chDbgAssert(currp->p_mtxlist != NULL, "chcond.c, chCondWaitS()");
+
+ mp = chMtxUnlockS(); /* unlocks the condvar mutex */
+ prio_insert(currp, &cp->c_queue); /* enters the condvar queue */
+ currp->p_wtcondp = cp; /* needed by the tracer */
+ chSchGoSleepS(PRWTCOND); /* waits on the condvar */
+ msg = currp->p_rdymsg; /* fetches the wakeup message */
+ chMtxLockS(mp); /* atomically relocks the mutex */
+ return msg; /* returns the wakeup message */
+}
+
+#ifdef CH_USE_CONDVARS_TIMEOUT
+/**
+ * Wait on the condition variable releasing the mutex lock.
+ *
+ * Releases the mutex, waits on the condition variable, and finally acquires
+ * the mutex again. This is done atomically.
+ *
+ * The thread MUST already have locked the mutex when calling chCondWait().
+ *
+ * @param cp pointer to the \p CondVar structure
+ * @param time the number of ticks before the operation fails
+ * @return The wakep mode.
+ * @retval RDY_OK if the condvar was signaled using chCondSignal().
+ * @retval RDY_RESET if the condvar was signaled using chCondBroadcast().
+ * @retval RDY_TIMEOUT if the condvar was not signaled within the specified
+ * timeout.
+ */
+msg_t chCondWaitTimeout(CondVar *cp, systime_t time) {
+ msg_t msg;
+
+ chSysLock();
+
+ msg = chCondWaitTimeoutS(cp, time);
+
+ chSysUnlock();
+ return msg;
+}
+
+/**
+ * Wait on the condition variable releasing the mutex lock.
+ *
+ * Releases the mutex, waits on the condition variable, and finally acquires
+ * the mutex again. This is done atomically.
+ *
+ * The thread MUST already have locked the mutex when calling chCondWait().
+ *
+ * @param cp pointer to the \p CondVar structure
+ * @param time the number of ticks before the operation fails
+ * @return The wakep mode.
+ * @retval RDY_OK if the condvar was signaled using chCondSignal().
+ * @retval RDY_RESET if the condvar was signaled using chCondBroadcast().
+ * @retval RDY_TIMEOUT if the condvar was not signaled within the specified
+ * timeout.
+ * @note This function must be called within a \p chSysLock() / \p chSysUnlock()
+ */
+msg_t chCondWaitTimeoutS(CondVar *cp, systime_t time) {
+ Mutex *mp;
+ msg_t msg;
+
+ chDbgAssert(currp->p_mtxlist != NULL, "chcond.c, chCondWaitS()");
+
+ mp = chMtxUnlockS(); /* unlocks the condvar mutex */
+ prio_insert(currp, &cp->c_queue); /* enters the condvar queue */
+ currp->p_wtcondp = cp; /* needed by the tracer */
+ chSchGoSleepTimeoutS(PRWTCOND, time); /* waits on the condvar */
+ msg = currp->p_rdymsg; /* fetches the wakeup message */
+ chMtxLockS(mp); /* atomically relocks the mutex */
+ return msg; /* returns the wakeup message */
+}
+#endif /* CH_USE_CONDVARS_TIMEOUT */
+
+#endif /* defined(CH_USE_CONDVARS) && defined(CH_USE_MUTEXES) */
+
+/** @} */
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