From 5de7877d74fded76954df070ca4c539113f487d8 Mon Sep 17 00:00:00 2001
From: uvos <devnull@uvos.xyz>
Date: Mon, 3 Apr 2023 21:34:00 +0200
Subject: [PATCH] Make exit not racey

---
 main.cpp | 40 ++++++++++++++++++++++++++--------------
 1 file changed, 26 insertions(+), 14 deletions(-)

diff --git a/main.cpp b/main.cpp
index 1a6ccec..7964879 100644
--- a/main.cpp
+++ b/main.cpp
@@ -22,14 +22,14 @@ void intHandler(int dummy)
 
 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";
+	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";
 }
 
 
@@ -69,7 +69,7 @@ static int parseCmdArgs(int argc, char** argv, Config *config)
 	return 0;
 }
 
-void recvThreadFunction(int serial, int signal)
+void recvThreadFunction(int serial, int exitfd)
 {
 	int pollQue = epoll_create1(0);
 	struct epoll_event ev = {};
@@ -78,14 +78,14 @@ void recvThreadFunction(int serial, int signal)
 	ev.data.fd = serial;
 	epoll_ctl(pollQue, EPOLL_CTL_ADD, serial, &ev);
 	ev.events = EPOLLIN;
-	ev.data.fd = signal;
-	epoll_ctl(pollQue, EPOLL_CTL_ADD, signal, &ev);
+	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 == signal)
+		if(event.data.fd == exitfd)
 			break;
 		std::this_thread::sleep_for(std::chrono::milliseconds(100));
 		char buffer[4096];
@@ -148,7 +148,15 @@ int main(int argc, char* argv[])
 	signal(SIGTERM, intHandler);
 	signal(SIGPIPE, SIG_IGN);
 
-	std::thread readThread(recvThreadFunction, serial, sigfd);
+	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);
@@ -163,13 +171,17 @@ int main(int argc, char* argv[])
 	epoll_ctl(pollQue, EPOLL_CTL_ADD, sigfd, &ev);
 
 	struct epoll_event event;
-	int ret;
 	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();