Make exit not racey

CMakeLists.txt

@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 3.0)
+
+project(serialterminal)
+
+set(SRC_FILES main.cpp serial_io.cpp )
+set(LIBS -pthread -lreadline)
+
+add_executable(${PROJECT_NAME} ${SRC_FILES})
+
+target_link_libraries( ${PROJECT_NAME} ${LIBS})
+set_target_properties( ${PROJECT_NAME} PROPERTIES COMPILE_FLAGS -m64 LINK_FLAGS -m64)
+add_definitions("-std=c++11 -Wall")
+
+set(CMAKE_INSTALL_PREFIX /usr)
+install(TARGETS serialterminal RUNTIME DESTINATION bin)

main.cpp

@@ -0,0 +1,194 @@
+#include <bits/types/sig_atomic_t.h>
+#include <chrono>
+#include <iostream>
+#include <string.h>
+#include <string>
+#include <thread>
+#include <readline/readline.h>
+#include <readline/history.h>
+#include <signal.h>
+#include <sys/signalfd.h>
+#include <sys/epoll.h>
+
+#include "serial_io.h"
+
+sig_atomic_t stop = false;
+constexpr int HISTORY_SIZE = 100;
+
+void intHandler(int dummy)
+{
+	stop = true;
+}
+
+static void printUsage()
+{
+	std::cout<<"usage mulitplexer [option]\n"
+		<<"Available options:\n"
+		<<"-h, --help       print this help\n"
+		<<"-p, --serialport serial port device to use\n"
+		<<"-P, --port       tcp port to use\n"
+		<<"-b, --baud       set baud rate with termios id\n"
+		<<"-r, --rates      list Available baud rates\n"
+		<<"-s, --sinkless   run without serial port\n";
+}
+
+
+struct Config
+{
+	std::string portFileName = "/dev/ttyUSB0";
+	unsigned short port = 6856;
+	int baud = B9600;
+	bool noSerial = false;
+};
+
+static int parseCmdArgs(int argc, char** argv, Config *config)
+{
+	for (int i = 1; i < argc; i++)
+	{
+		if (std::string(argv[i]) == "--help" || std::string(argv[i]) == "-h")
+		{
+			printUsage();
+			return -1;
+		}
+		else if (std::string(argv[i]) == "--serialport" || std::string(argv[i]) == "-p")
+		{
+			if(argc > i) config->portFileName = argv[i+1];
+			else return -1;
+		}
+		else if (std::string(argv[i]) == "--baud" || std::string(argv[i]) == "-b")
+		{
+			if(argc > i) config->baud = atoi(argv[i+1]);
+			else return -1;
+		}
+		else if (std::string(argv[i]) == "-r" || std::string(argv[i]) == "--rates")
+		{
+			printRates();
+			return -1;
+		}
+	}
+	return 0;
+}
+
+void recvThreadFunction(int serial, int exitfd)
+{
+	int pollQue = epoll_create1(0);
+	struct epoll_event ev = {};
+
+	ev.events = EPOLLIN;
+	ev.data.fd = serial;
+	epoll_ctl(pollQue, EPOLL_CTL_ADD, serial, &ev);
+	ev.events = EPOLLIN;
+	ev.data.fd = exitfd;
+	epoll_ctl(pollQue, EPOLL_CTL_ADD, exitfd, &ev);
+
+	struct epoll_event event;
+	int ret;
+	while((ret = epoll_wait(pollQue, &event, 1, -1)) > 0)
+	{
+		if(event.data.fd == exitfd)
+			break;
+		std::this_thread::sleep_for(std::chrono::milliseconds(100));
+		char buffer[4096];
+		int readlen = sRead(serial, buffer, 4095);
+		if(readlen > 0)
+		{
+			buffer[readlen] = '\0';
+			rl_clear_visible_line();
+			std::cout<<buffer;
+			if(buffer[readlen-1] != '\n')
+				std::cout<<'\n';
+			rl_on_new_line();
+			rl_redisplay();
+		}
+	}
+	if(ret < 0)
+		perror("epoll_wait: ");
+	close(pollQue);
+}
+
+int cb_serial;
+static void cb_linehandler(char *line)
+{
+	if(line != NULL)
+	{
+		if(*line)
+		{
+			add_history(line);
+			sWrite(cb_serial, line, strlen(line));
+			sWrite(cb_serial, "\n", 1);
+		}
+		free(line);
+	}
+}
+
+int main(int argc, char* argv[])
+{
+	Config config;
+
+	if(parseCmdArgs(argc, argv, &config) != 0)
+		return -1;
+
+	std::cout<<"UVOS serial terminal v1.1\n";
+
+	int serial = -1;
+	std::cout<<"Using serial port: "<<config.portFileName<<" at "<<config.baud<<" baud\n";
+	serial = serialport_init(config.portFileName.c_str(), config.baud);
+	if(serial == -1)
+		return 1;
+	cb_serial = serial;
+
+	tcflush(serial, TCIOFLUSH);
+
+	sigset_t set;
+	sigisemptyset(&set);
+	sigaddset(&set, SIGINT);
+	sigaddset(&set, SIGTERM);
+	int sigfd = signalfd(-1, &set, 0);
+	signal(SIGINT, intHandler);
+	signal(SIGTERM, intHandler);
+	signal(SIGPIPE, SIG_IGN);
+
+	int exitPipe[2];
+	int ret = pipe(exitPipe);
+	if(ret)
+	{
+		std::cout<<"Could not create pipe\n";
+		return 3;
+	}
+
+	std::thread readThread(recvThreadFunction, serial, exitPipe[0]);
+
+	rl_catch_signals = 0;
+	rl_callback_handler_install ("> ", cb_linehandler);
+
+	int pollQue = epoll_create1(0);
+	struct epoll_event ev = {};
+	ev.events = EPOLLIN;
+	ev.data.fd = fileno(rl_instream);
+	epoll_ctl(pollQue, EPOLL_CTL_ADD, fileno(rl_instream), &ev);
+	ev.events = EPOLLIN;
+	ev.data.fd = sigfd;
+	epoll_ctl(pollQue, EPOLL_CTL_ADD, sigfd, &ev);
+
+	struct epoll_event event;
+	while((ret = epoll_wait(pollQue, &event, 1, -1)) > 0)
+	{
+		if(event.data.fd == sigfd)
+		{
+			write(exitPipe[1], "\n", 1);
+			break;
+		}
+		else
+		{
+			rl_callback_read_char();
+		}
+	}
+
+	readThread.join();
+	close(pollQue);
+	close(sigfd);
+	rl_callback_handler_remove();
+	std::cout<<std::endl;
+	return 0;
+}
+

serial_io.cpp

@@ -0,0 +1,105 @@
+#include "serial_io.h"
+
+void sWrite(int port, char string[], size_t length)
+{
+    if(port != -1) write(port, string, length);
+    
+}
+
+void sWrite(int port, const char string[], size_t length)
+{
+    if(port != -1) write(port, string, length);
+}
+
+ssize_t sRead(int port, void *buf, size_t count)
+{
+    return (port != -1) ? read(port, buf, count) : 0;
+}
+
+#ifdef __cplusplus
+void printRates()
+{
+std::cout<<"Rates:\n"\
+		 <<"Unchanged 0\n"        \
+         <<"B50       "<<B50<<'\n'\
+         <<"B75       "<<B75<<'\n'\
+         <<"B110      "<<B110<<'\n'\
+         <<"B134      "<<B134<<'\n'\
+         <<"B150      "<<B150<<'\n'\
+         <<"B200      "<<B200<<'\n'\
+         <<"B300      "<<B300<<'\n'\
+         <<"B600      "<<B600<<'\n'\
+         <<"B1200     "<<B1200<<'\n'\
+         <<"B1800     "<<B1800<<'\n'\
+         <<"B2400     "<<B2400<<'\n'\
+         <<"B4800     "<<B4800<<'\n'\
+         <<"B9600     "<<B9600<<'\n'\
+         <<"B19200    "<<B19200<<'\n'\
+         <<"B38400    "<<B38400<<'\n'\
+         <<"B57600    "<<B57600<<'\n'\
+         <<"B115200   "<<B115200<<'\n'\
+         <<"B230400   "<<B230400<<'\n'\
+         <<"B460800   "<<B460800<<'\n'\
+         <<"B500000   "<<B500000<<'\n'\
+         <<"B576000   "<<B576000<<'\n'\
+         <<"B921600   "<<B921600<<'\n'\
+         <<"B1000000   "<<B1000000<<'\n'\
+         <<"B1152000   "<<B1152000<<'\n'\
+         <<"B1500000   "<<B1500000<<'\n';
+}
+#endif
+
+int serialport_init(const char* device, int baud)
+{
+    int fd;
+    struct termios toptions;
+    fd = open(device, O_RDWR | O_NOCTTY | O_NDELAY);
+    if (fd == -1)
+    {
+    perror("init_serialport: Unable to open port ");
+    return -1;
+    }
+
+    if (tcgetattr(fd, &toptions) < 0)
+    {
+        perror("init_serialport: Couldn't get term attributes");
+        return -1;
+    }
+    // 8N1
+    toptions.c_cflag &= ~PARENB;
+    toptions.c_cflag &= ~CSTOPB;
+    toptions.c_cflag &= ~CSIZE;
+    toptions.c_cflag |= CS8;
+    
+    // no flow control
+    toptions.c_cflag &= ~(CRTSCTS | CLOCAL);
+
+    //Make Raw
+    toptions.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
+    toptions.c_oflag &= ~OPOST; //hmm examine
+    toptions.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+    toptions.c_cflag &= ~(CSIZE | PARENB);
+    toptions.c_cflag |= CS8;
+    
+	if(baud != 0)
+	{
+		int error = cfsetispeed(&toptions, baud) | cfsetospeed(&toptions, baud);
+
+		if(error)
+		{
+			perror("init_serialport: Couldn't set baud rate");
+			return -1;
+		}
+	}
+    // see: http://unixwiz.net/techtips/termios-vmin-vtime.html
+    toptions.c_cc[VMIN]  = 0;
+    toptions.c_cc[VTIME] = 40;
+    fcntl(fd, F_SETFL, FNDELAY);
+    if( tcsetattr(fd, TCSANOW, &toptions) < 0)
+    {
+        perror("init_serialport: Couldn't set term attributes");
+        return -1;
+    }
+    return fd;
+}
+

serial_io.h

@@ -0,0 +1,26 @@
+#ifndef SERIAL_H
+#define SERIAL_H
+#include <termios.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#ifdef __cplusplus
+#include <iostream>
+#endif
+
+#define BAUDRATE B38400
+
+void sWrite(int port, char string[], size_t length);
+
+void sWrite(int port, const char string[], size_t length);
+
+ssize_t sRead(int port, void *buf, size_t count);
+
+#ifdef __cplusplus
+void printRates();
+#endif
+
+int serialport_init(const char* device, int baud = BAUDRATE);
+
+
+#endif // SERIAL_H