From 1f10b4e3364de54f108bc42e4f789893afd44c9a Mon Sep 17 00:00:00 2001
From: Mickael GARDET <m.gardet@overkiz.com>
Date: Thu, 1 Sep 2016 17:12:03 +0200
Subject: [PATCH] Serial POSIX: Check if tty is already opened by another
 stm32flash

---
 serial_posix.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/serial_posix.c b/serial_posix.c
index 46b8a94..020e796 100644
--- a/serial_posix.c
+++ b/serial_posix.c
@@ -25,6 +25,7 @@
 #include <termios.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
+#include <sys/file.h>
 
 #include "serial.h"
 #include "port.h"
@@ -45,6 +46,13 @@ static serial_t *serial_open(const char *device)
 		free(h);
 		return NULL;
 	}
+
+	if(lockf(h->fd,F_TLOCK,0) != 0)
+	{
+		fprintf(stderr, "Error: %s is already open\n", device);
+		free(h);
+		return NULL;
+	}
 	fcntl(h->fd, F_SETFL, 0);
 
 	tcgetattr(h->fd, &h->oldtio);
@@ -62,6 +70,7 @@ static void serial_close(serial_t *h)
 {
 	serial_flush(h);
 	tcsetattr(h->fd, TCSANOW, &h->oldtio);
+	lockf(h->fd, F_ULOCK, 0);
 	close(h->fd);
 	free(h);
 }
-- 
2.17.1