/****************************************************************************
* examples/poll/select_listener.c
*
* Copyright (C) 2008, 2009 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 <sys/select.h>
#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>
#include <fcntl.h>
#include <errno.h>
#include <debug.h>
#include "poll_internal.h"
/****************************************************************************
* Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: select_listener
****************************************************************************/
void *select_listener(pthread_addr_t pvarg)
{
fd_set rfds;
struct timeval tv;
char buffer[64];
ssize_t nbytes;
bool timeout;
bool ready;
int fd;
int ret;
/* Open the FIFO for non-blocking read */
message("select_listener: Opening %s for non-blocking read\n", FIFO_PATH2);
fd = open(FIFO_PATH2, O_RDONLY|O_NONBLOCK);
if (fd < 0)
{
message("select_listener: ERROR Failed to open FIFO %s: %d\n",
FIFO_PATH2, errno);
(void)close(fd);
return (void*)-1;
}
/* Loop forever */
for (;;)
{
message("select_listener: Calling select()\n");
FD_ZERO(&rfds);
FD_SET(fd, &rfds);
tv.tv_sec = SELECT_LISTENER_DELAY;
tv.tv_usec = 0;
timeout = false;
ready = false;
ret = select(fd+1, (FAR fd_set*)&rfds, (FAR fd_set*)NULL, (FAR fd_set*)NULL, &tv);
message("\nselect_listener: select returned: %d\n", ret);
if (ret < 0)
{
message("select_listener: ERROR select failed: %d\n");
}
else if (ret == 0)
{
message("select_listener: Timeout\n");
timeout = true;
}
else
{
if (ret != 1)
{
message("select_listener: ERROR poll reported: %d\n");
}
else
{
ready = true;
}
if (!FD_ISSET(fd, rfds))
{
message("select_listener: ERROR fd=%d not in fd_set\n");
}
}
/* In any event, read until the pipe is empty */
do
{
nbytes = read(fd, buffer, 63);
if (nbytes <= 0)
{
if (nbytes == 0 || errno == EAGAIN)
{
if (ready)
{
message("select_listener: ERROR no read data\n");
}
}
else if (errno != EINTR)
{
message("select_listener: read failed: %d\n", errno);
}
nbytes = 0;
}
else
{
if (timeout)
{
message("select_listener: ERROR? Poll timeout, but data read\n");
message(" (might just be a race condition)\n");
}
buffer[nbytes] = '\0';
message("select_listener: Read '%s' (%d bytes)\n", buffer, nbytes);
}
timeout = false;
ready = false;
}
while (nbytes > 0);
/* Make sure that everything is displayed */
msgflush();
}
/* Won't get here */
(void)close(fd);
return NULL;
}