minor refactoring

src/xioctl.h

@@ -0,0 +1,55 @@
+/*****************************************************************************
+#    uStreamer - Lightweight and fast MJPG-HTTP streamer.                    #
+#                                                                            #
+#    Copyright (C) 2018  Maxim Devaev <mdevaev@gmail.com>                    #
+#                                                                            #
+#    This program is free software: you can redistribute it and/or modify    #
+#    it under the terms of the GNU General Public License as published by    #
+#    the Free Software Foundation, either version 3 of the License, or       #
+#    (at your option) any later version.                                     #
+#                                                                            #
+#    This program is distributed in the hope that it will be useful,         #
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of          #
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           #
+#    GNU General Public License for more details.                            #
+#                                                                            #
+#    You should have received a copy of the GNU General Public License       #
+#    along with this program.  If not, see <https://www.gnu.org/licenses/>.  #
+#                                                                            #
+*****************************************************************************/
+
+
+#pragma once
+
+#include <errno.h>
+
+#include <sys/ioctl.h>
+
+#include "tools.h"
+#include "logging.h"
+
+
+#define XIOCTL_RETRIES 4
+
+
+INLINE int xioctl(const int fd, const int request, void *arg) {
+	int retries = XIOCTL_RETRIES;
+	int retval = -1;
+
+	do {
+		retval = ioctl(fd, request, arg);
+	} while (
+		retval
+		&& retries--
+		&& (
+			errno == EINTR
+			|| errno == EAGAIN
+			|| errno == ETIMEDOUT
+		)
+	);
+
+	if (retval && retries <= 0) {
+		LOG_PERROR("ioctl(%d) retried %d times; giving up", request, XIOCTL_RETRIES);
+	}
+	return retval;
+}