/************************************************************
* uip-wait.c
*
* Copyright (C) 2007 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* 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 <semaphore.h>
#include <wdog.h>
#include <arch/irq.h>
#include <net/uip/uip.h>
/************************************************************
* Definitions
************************************************************/
/************************************************************
* Private Data
************************************************************/
/* Threads and tasks can both wait a semaphore. This
* initializer uses internal, non-portable knowledge of the\
* structure of sem_t to initialize it to the value 0.
*/
static sem_t uip_waitsem = { 0 }; /* Semaphore to wait on */
static uint16 uip_waitflags = 0; /* UIP flags to wait for */
/************************************************************
* Private Functions
************************************************************/
/* Called from the timer interrupt handler when a event wait
* watchdog expires.
*/
static void uip_event_timeout(int argc, uint32 itcb, ...)
{
irqstate_t save = irqsave(); /* Should not be necessary */
uip_flags |= UIP_APPTIMEOUT; /* Set software timeout event */
uip_event_signal(); /* Signal the waiting thread/task */
irqrestore(save); /* Restore interrupts */
}
/************************************************************
* Global Functions
************************************************************/
/* This function is called user code to set up the wait */
int uip_event_timedwait(uint16 waitflags, int timeout)
{
/* Prevent conflicts with the interrupt level operation of
* uip_event_signal().
*/
irqstate_t save = irqsave();
WDOG_ID wdog;
/* At present, we support only a single waiter. If uip_waitflags
* is non-zero on entry, then there is a problem.
*/
if ( uip_waitflags == 0)
{
/* If the requested event bits are not set in the uip_flags,
* then wait. We will be awakened as soon as an interrupt is
* received that sets these bits.
*/
goto errout_with_irqdisabled;
}
/* Loop until the requested bits are set in the flags */
while ((waitflags & uip_flags) != 0)
{
/* Set the event flags that the caller is waiting on */
uip_waitflags = waitflags;
/* Was a timeut requested as well? */
if (timeout)
{
/* Yes, then set the application timeout event as well */
uip_waitflags |= UIP_APPTIMEOUT;
/* Create a watchdog */
wdog = wd_create();
if (!wdog)
{
goto errout_with_irqdisabled;
}
/* Start the watchdog */
wd_start(wdog, timeout, (wdentry_t)uip_event_timeout, 0);
}
/* Wait for the event (or timeout) to occur */
if (sem_wait(&uip_waitsem) != 0)
{
goto errout_with_watchdog;
}
/* We no longer need the watchdog */
if (wdog)
{
wd_delete(wdog);
wdog = NULL;
}
}
irqrestore(save);
return OK;
errout_with_watchdog:
if (wdog)
{
wd_delete(wdog);
}
errout_with_irqdisabled:
irqrestore(save);
return ERROR;
}
/* This function is called from uip_interrupt() to wake up any
* waiting threads/tasks.
*/
void uip_event_signal(void)
{
/* If any bits in uip_waitflags match bits set in uip_flags, then
* there must be a thread/task waiting for this event to occur.
*/
if ((uip_waitflags & uip_flags) != 0)
{
sem_post(&uip_waitsem); /* Post the event */
uip_waitflags = 0; /* Prohibit posting the event multiple times */
}
}
