/****************************************************************************
* examples/poll/poll_listener.c
*
* Copyright (C) 2008 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 <sys/stat.h>
#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
#include <poll.h>
#include <fcntl.h>
#include <errno.h>
#include <debug.h>
#include "poll_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
#if defined(CONFIG_DEV_CONSOLE) && !defined(CONFIG_DEV_LOWCONSOLE)
# define HAVE_CONSOLE
# define NPOLLFDS 2
# define CONSNDX 0
# define FIFONDX 1
#else
# undef HAVE_CONSOLE
# define NPOLLFDS 1
# define FIFONDX 0
#endif
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: poll_listener
****************************************************************************/
void *poll_listener(pthread_addr_t pvarg)
{
struct pollfd fds[NPOLLFDS];
char buffer[64];
ssize_t nbytes;
bool timeout;
bool pollin;
int nevents;
int fd;
int ret;
int i;
/* Open the FIFO for non-blocking read */
message("poll_listener: Opening %s for non-blocking read\n", FIFO_PATH1);
fd = open(FIFO_PATH1, O_RDONLY|O_NONBLOCK);
if (fd < 0)
{
message("poll_listener: ERROR Failed to open FIFO %s: %d\n",
FIFO_PATH1, errno);
(void)close(fd);
return (void*)-1;
}
/* Loop forever */
for (;;)
{
message("poll_listener: Calling poll()\n");
memset(fds, 0, sizeof(struct pollfd)*NPOLLFDS);
#ifdef HAVE_CONSOLE
fds[CONSNDX].fd = 0;
fds[CONSNDX].events = POLLIN;
fds[CONSNDX].revents = 0;
#endif
fds[FIFONDX].fd = fd;
fds[FIFONDX].events = POLLIN;
fds[FIFONDX].revents = 0;
timeout = false;
pollin = false;
ret = poll(fds, NPOLLFDS, POLL_LISTENER_DELAY);
message("\npoll_listener: poll returned: %d\n", ret);
if (ret < 0)
{
message("poll_listener: ERROR poll failed: %d\n", errno);
}
else if (ret == 0)
{
message("poll_listener: Timeout\n");
timeout = true;
}
else if (ret > NPOLLFDS)
{
message("poll_listener: ERROR poll reported: %d\n");
}
else
{
pollin = true;
}
nevents = 0;
for (i = 0; i < NPOLLFDS; i++)
{
message("poll_listener: FIFO revents[%d]=%02x\n", i, fds[i].revents);
if (timeout)
{
if (fds[i].revents != 0)
{
message("poll_listener: ERROR? expected revents=00, received revents[%d]=%02x\n",
fds[i].revents, i);
}
}
else if (pollin)
{
if (fds[i].revents == POLLIN)
{
nevents++;
}
else if (fds[i].revents != 0)
{
message("poll_listener: ERROR unexpected revents[i]=%02x\n",
i, fds[i].revents);
}
}
}
if (pollin && nevents != ret)
{
message("poll_listener: ERROR found %d events, poll reported %d\n", nevents, ret);
}
/* In any event, read until the pipe/serial is empty */
for (i = 0; i < NPOLLFDS; i++)
{
do
{
#ifdef HAVE_CONSOLE
/* Hack to work around the fact that the console driver on the
* simulator is always non-blocking.
*/
if (i == CONSNDX)
{
if ((fds[CONSNDX].revents & POLLIN) != 0)
{
buffer[0] = getchar();
nbytes = 1;
}
else
{
nbytes = 0;
}
}
else
#endif
{
/* The pipe works differently, it returns whatever data
* it has available without blocking.
*/
nbytes = read(fds[i].fd, buffer, 63);
}
if (nbytes <= 0)
{
if (nbytes == 0 || errno == EAGAIN)
{
if ((fds[i].revents & POLLIN) != 0)
{
message("poll_listener: ERROR no read data[%d]\n", i);
}
}
else if (errno != EINTR)
{
message("poll_listener: read[%d] failed: %d\n", i, errno);
}
nbytes = 0;
}
else
{
if (timeout)
{
message("poll_listener: ERROR? Poll timeout, but data read[%d]\n", i);
message(" (might just be a race condition)\n");
}
buffer[nbytes] = '\0';
message("poll_listener: Read[%d] '%s' (%d bytes)\n", i, buffer, nbytes);
}
/* Suppress error report if no read data on the next time through */
fds[i].revents = 0;
}
while (nbytes > 0);
}
/* Make sure that everything is displayed */
msgflush();
}
/* Won't get here */
(void)close(fd);
return NULL;
}
