Move C/C++ sources to src subdirectory

src/rw_blocking.h

@@ -0,0 +1,12 @@
+// Copyright (c) Vitaliy Filippov, 2019+
+// License: VNPL-1.1 or GNU GPL-2.0+ (see README.md for details)
+
+#pragma once
+
+#include <unistd.h>
+#include <sys/uio.h>
+
+int read_blocking(int fd, void *read_buf, size_t remaining);
+int write_blocking(int fd, void *write_buf, size_t remaining);
+int readv_blocking(int fd, iovec *iov, int iovcnt);
+int writev_blocking(int fd, iovec *iov, int iovcnt);