diff options
Diffstat (limited to 'nuttx/sched/mq_timedsend.c')
| -rw-r--r-- | nuttx/sched/mq_timedsend.c | 319 |
1 files changed, 319 insertions, 0 deletions
diff --git a/nuttx/sched/mq_timedsend.c b/nuttx/sched/mq_timedsend.c new file mode 100644 index 000000000..745cc6272 --- /dev/null +++ b/nuttx/sched/mq_timedsend.c @@ -0,0 +1,319 @@ +/**************************************************************************** + * sched/mq_timedsend.c + * + * Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name NuttX nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <nuttx/config.h> + +#include <sys/types.h> +#include <stdint.h> +#include <stdbool.h> +#include <unistd.h> +#include <mqueue.h> +#include <wdog.h> +#include <errno.h> +#include <debug.h> +#include <nuttx/arch.h> + +#include "clock_internal.h" +#include "os_internal.h" +#include "mq_internal.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Type Declarations + ****************************************************************************/ + +/**************************************************************************** + * Global Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Variables + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: mq_sndtimeout + * + * Description: + * This function is called if the timeout elapses before the message queue + * becomes non-full. + * + * Parameters: + * argc - the number of arguments (should be 1) + * pid - the task ID of the task to wakeup + * + * Return Value: + * None + * + * Assumptions: + * + ****************************************************************************/ + +static void mq_sndtimeout(int argc, uint32_t pid) +{ + FAR _TCB *wtcb; + irqstate_t saved_state; + + /* Disable interrupts. This is necessary because an interrupt handler may + * attempt to send a message while we are doing this. + */ + + saved_state = irqsave(); + + /* Get the TCB associated with this pid. It is possible that task may no + * longer be active when this watchdog goes off. + */ + + wtcb = sched_gettcb((pid_t)pid); + + /* It is also possible that an interrupt/context switch beat us to the + * punch and already changed the task's state. + */ + + if (wtcb && wtcb->task_state == TSTATE_WAIT_MQNOTFULL) + { + /* Restart with task with a timeout error */ + + mq_waitirq(wtcb, ETIMEDOUT); + } + + /* Interrupts may now be re-enabled. */ + + irqrestore(saved_state); +} + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: mq_send + * + * Description: + * This function adds the specificied message (msg) to the message queue + * (mqdes). The "msglen" parameter specifies the length of the message + * in bytes pointed to by "msg." This length must not exceed the maximum + * message length from the mq_getattr(). + * + * If the message queue is not full, mq_timedsend() place the message in the + * message queue at the position indicated by the "prio" argrument. + * Messages with higher priority will be inserted before lower priority + * messages. The value of "prio" must not exceed MQ_PRIO_MAX. + * + * If the specified message queue is full and O_NONBLOCK is not set in the + * message queue, then mq_timedsend() will block until space becomes available + * to the queue the message or a timeout occurs. + * + * mq_timedsend() behaves just like mq_send(), except that if the queue + * is full and the O_NONBLOCK flag is not enabled for the message queue + * description, then abstime points to a structure which specifies a + * ceiling on the time for which the call will block. This ceiling is an + * absolute timeout in seconds and nanoseconds since the Epoch (midnight + * on the morning of 1 January 1970). + * + * If the message queue is full, and the timeout has already expired by + * the time of the call, mq_timedsend() returns immediately. + * + * Parameters: + * mqdes - Message queue descriptor + * msg - Message to send + * msglen - The length of the message in bytes + * prio - The priority of the message + * abstime - the absolute time to wait until a timeout is decleared + * + * Return Value: + * On success, mq_send() returns 0 (OK); on error, -1 (ERROR) + * is returned, with errno set to indicate the error: + * + * EAGAIN The queue was empty, and the O_NONBLOCK flag was set for the + * message queue description referred to by mqdes. + * EINVAL Either msg or mqdes is NULL or the value of prio is invalid. + * EPERM Message queue opened not opened for writing. + * EMSGSIZE 'msglen' was greater than the maxmsgsize attribute of the + * message queue. + * EINTR The call was interrupted by a signal handler. + * + * Assumptions/restrictions: + * + ****************************************************************************/ + +int mq_timedsend(mqd_t mqdes, const char *msg, size_t msglen, int prio, + const struct timespec *abstime) +{ + WDOG_ID wdog; + FAR msgq_t *msgq; + FAR mqmsg_t *mqmsg = NULL; + irqstate_t saved_state; + int ret = ERROR; + + DEBUGASSERT(up_interrupt_context() == false); + + /* Verify the input parameters -- setting errno appropriately + * on any failures to verify. + */ + + if (mq_verifysend(mqdes, msg, msglen, prio) != OK) + { + return ERROR; + } + + if (!abstime || abstime->tv_sec < 0 || abstime->tv_nsec > 1000000000) + { + set_errno(EINVAL); + return ERROR; + } + + /* Get a pointer to the message queue */ + + msgq = mqdes->msgq; + + /* Create a watchdog. We will not actually need this watchdog + * unless the queue is full, but we will reserve it up front + * before we enter the following critical section. + */ + + wdog = wd_create(); + if (!wdog) + { + set_errno(EINVAL); + return ERROR; + } + + /* Allocate a message structure: + * - If we are called from an interrupt handler, or + * - If the message queue is not full, or + */ + + sched_lock(); + saved_state = irqsave(); + if (up_interrupt_context() || /* In an interrupt handler */ + msgq->nmsgs < msgq->maxmsgs) /* OR Message queue not full */ + { + /* Allocate the message */ + + irqrestore(saved_state); + mqmsg = mq_msgalloc(); + } + else + { + int ticks; + + /* We are not in an interupt handler and the message queue is full. + * set up a timed wait for the message queue to become non-full. + * + * Convert the timespec to clock ticks. We must have interrupts + * disabled here so that this time stays valid until the wait begins. + */ + + int result = clock_abstime2ticks(CLOCK_REALTIME, abstime, &ticks); + + /* If the time has already expired and the message queue is empty, + * return immediately. + */ + + if (result == OK && ticks <= 0) + { + result = ETIMEDOUT; + } + + /* Handle any time-related errors */ + + if (result != OK) + { + set_errno(result); + ret = ERROR; + } + + /* Start the watchdog and begin the wait for MQ not full */ + + if (result == OK) + { + /* Start the watchdog */ + + wd_start(wdog, ticks, (wdentry_t)mq_sndtimeout, 1, getpid()); + + /* And wait for the message queue to be non-empty */ + + ret = mq_waitsend(mqdes); + + /* This may return with an error and errno set to either EINTR + * or ETIMEOUT. Cancel the watchdog timer in any event. + */ + + wd_cancel(wdog); + } + + /* That is the end of the atomic operations */ + + irqrestore(saved_state); + + /* If any of the above failed, set the errno. Otherwise, there should + * be space for another message in the message queue. NOW we can allocate + * the message structure. + */ + + if (ret == OK) + { + mqmsg = mq_msgalloc(); + } + } + + /* Check if we were able to get a message structure -- this can fail + * either because we cannot send the message (and didn't bother trying + * to allocate it) or because the allocation failed. + */ + + if (mqmsg) + { + /* Yes, peform the message send. */ + + ret = mq_dosend(mqdes, mqmsg, msg, msglen, prio); + } + + sched_unlock(); + wd_delete(wdog); + return ret; +} + |