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| author | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2009-08-16 13:07:24 +0000 |
|---|---|---|
| committer | gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4> | 2009-08-16 13:07:24 +0000 |
| commit | 1ea7355d85e316aadfd90468b3e808bb3dc95ee9 (patch) | |
| tree | 7d9c3cd8733553982b9d0a55e1ddff036a6d9b4c /os/kernel/src/chcond.c | |
| parent | 51e3bee83961243f5f0ba01537630f5a3d070c36 (diff) | |
| download | ChibiOS-1ea7355d85e316aadfd90468b3e808bb3dc95ee9.tar.gz ChibiOS-1ea7355d85e316aadfd90468b3e808bb3dc95ee9.tar.bz2 ChibiOS-1ea7355d85e316aadfd90468b3e808bb3dc95ee9.zip | |
git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@1073 35acf78f-673a-0410-8e92-d51de3d6d3f4
Diffstat (limited to 'os/kernel/src/chcond.c')
| -rw-r--r-- | os/kernel/src/chcond.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/os/kernel/src/chcond.c b/os/kernel/src/chcond.c new file mode 100644 index 000000000..ef58f1ddf --- /dev/null +++ b/os/kernel/src/chcond.c @@ -0,0 +1,227 @@ +/*
+ 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.
+ */
+
+/**
+ * @file chcond.c
+ * @brief Condition Variables code.
+ * @addtogroup CondVars
+ * @{
+ */
+
+#include <ch.h>
+
+#if CH_USE_CONDVARS && CH_USE_MUTEXES
+
+/**
+ * @brief Initializes s @p CondVar structure.
+ *
+ * @param[out] cp pointer to a @p CondVar structure
+ * @note This function can be invoked from within an interrupt handler even if
+ * it is not an I-Class API because it does not touch any critical kernel
+ * data structure.
+ */
+void chCondInit(CondVar *cp) {
+
+ chDbgCheck(cp != NULL, "chCondInit");
+
+ queue_init(&cp->c_queue);
+}
+
+/**
+ * @brief Signals one thread that is waiting on the condition variable.
+ *
+ * @param[in] cp pointer to the @p CondVar structure
+ */
+void chCondSignal(CondVar *cp) {
+
+ chDbgCheck(cp != NULL, "chCondSignal");
+
+ chSysLock();
+ if (notempty(&cp->c_queue)) /* any thread ? */
+ chSchWakeupS(fifo_remove(&cp->c_queue), RDY_OK);
+ chSysUnlock();
+}
+
+/**
+ * @brief Signals one thread that is waiting on the condition variable.
+ *
+ * @param[in] cp pointer to the @p CondVar structure
+ */
+void chCondSignalI(CondVar *cp) {
+
+ chDbgCheck(cp != NULL, "chCondSignalI");
+
+ if (notempty(&cp->c_queue)) /* any thread ? */
+ chSchReadyI(fifo_remove(&cp->c_queue))->p_rdymsg = RDY_OK;
+}
+
+/**
+ * @brief Signals all threads that are waiting on the condition variable.
+ *
+ * @param[in] cp pointer to the @p CondVar structure
+ */
+void chCondBroadcast(CondVar *cp) {
+
+ chSysLock();
+ chCondBroadcastI(cp);
+ chSchRescheduleS();
+ chSysUnlock();
+}
+
+/**
+ * @brief Signals all threads that are waiting on the condition variable.
+ *
+ * @param[in] cp pointer to the @p CondVar structure
+ */
+void chCondBroadcastI(CondVar *cp) {
+
+ chDbgCheck(cp != NULL, "chCondBroadcastI");
+
+ /* 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;
+}
+
+/**
+ * @brief Waits on the condition variable releasing the mutex lock.
+ * @details Releases the mutex, waits on the condition variable, and finally
+ * acquires the mutex again. This is done atomically.
+ *
+ * @param[in] 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 The thread MUST already have locked the mutex when calling
+ * @p chCondWait().
+ */
+msg_t chCondWait(CondVar *cp) {
+ msg_t msg;
+
+ chSysLock();
+ msg = chCondWaitS(cp);
+ chSysUnlock();
+ return msg;
+}
+
+/**
+ * @brief Waits on the condition variable releasing the mutex lock.
+ * @details Releases the mutex, waits on the condition variable, and finally
+ * acquires the mutex again. This is done atomically.
+ *
+ * @param[in] 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 The thread MUST already have locked the mutex when calling
+ * @p chCondWaitS().
+ */
+msg_t chCondWaitS(CondVar *cp) {
+ Mutex *mp;
+ msg_t msg;
+
+ chDbgCheck(cp != NULL, "chCondWaitS");
+ chDbgAssert(currp->p_mtxlist != NULL,
+ "chCondWaitS(), #1",
+ "not owning a mutex");
+
+ 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 */
+}
+
+#if CH_USE_CONDVARS_TIMEOUT
+/**
+ * @brief Waits on the condition variable releasing the mutex lock.
+ * @details Releases the mutex, waits on the condition variable, and finally
+ * acquires the mutex again. This is done atomically.
+ *
+ * @param[in] cp pointer to the @p CondVar structure
+ * @param[in] time the number of ticks before the operation timeouts,
+ * the special value @p TIME_INFINITE is allowed.
+ * It is not possible to specify zero @p TIME_IMMEDIATE
+ * as timeout specification because it would make no sense
+ * in this function.
+ * @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 The thread MUST already have locked the mutex when calling
+ * @p chCondWaitTimeout().
+ */
+msg_t chCondWaitTimeout(CondVar *cp, systime_t time) {
+ msg_t msg;
+
+ chSysLock();
+ msg = chCondWaitTimeoutS(cp, time);
+ chSysUnlock();
+ return msg;
+}
+
+/**
+ * @brief Waits on the condition variable releasing the mutex lock.
+ * @details Releases the mutex, waits on the condition variable, and finally
+ * acquires the mutex again. This is done atomically.
+ *
+ * @param[in] cp pointer to the @p CondVar structure
+ * @param[in] time the number of ticks before the operation timeouts,
+ * the special value @p TIME_INFINITE is allowed.
+ * It is not possible to specify zero @p TIME_IMMEDIATE
+ * as timeout specification because it would make no sense
+ * in this function.
+ * @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 The thread MUST already have locked the mutex when calling
+ * @p chCondWaitTimeoutS().
+ */
+msg_t chCondWaitTimeoutS(CondVar *cp, systime_t time) {
+ Mutex *mp;
+ msg_t msg;
+
+ chDbgCheck(cp != NULL, "chCondWaitTimeoutS");
+ chDbgAssert(currp->p_mtxlist != NULL,
+ "chCondWaitTimeoutS(), #1",
+ "not owning a mutex");
+
+ 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 /* CH_USE_CONDVARS && CH_USE_MUTEXES */
+
+/** @} */
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