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Diffstat (limited to 'apps/examples/poll/select_listener.c')
| -rw-r--r-- | apps/examples/poll/select_listener.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/apps/examples/poll/select_listener.c b/apps/examples/poll/select_listener.c new file mode 100644 index 000000000..80039ada3 --- /dev/null +++ b/apps/examples/poll/select_listener.c @@ -0,0 +1,193 @@ +/**************************************************************************** + * examples/poll/select_listener.c + * + * Copyright (C) 2008, 2009 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 <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; +} |