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diff --git a/src/util/atomic_io.h b/src/util/atomic_io.h
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+/*
+    Authors:
+        Jan Cholasta <jcholast@redhat.com>
+
+    Copyright (C) 2012 Red Hat
+
+    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 <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef __SSSD_ATOMIC_IO_H__
+#define __SSSD_ATOMIC_IO_H__
+
+#include <unistd.h>
+#include <stdbool.h>
+#include <poll.h>
+#include <errno.h>
+
+/* Performs a read or write operation in an manner that is seemingly atomic
+ * to the caller.
+ *
+ * Please note that the function does not perform any asynchronous operation
+ * so the operation might potentially block
+ */
+ssize_t sss_atomic_io_s(int fd, void *buf, size_t n, bool do_read);
+
+#define sss_atomic_read_s(fd, buf, n)  sss_atomic_io_s(fd, buf, n, true)
+#define sss_atomic_write_s(fd, buf, n) sss_atomic_io_s(fd, buf, n, false)
+
+/**
+ * Write length of the buffer then the buffer itself.
+ *
+ * (uint32_t)length + buffer
+ */
+ssize_t sss_atomic_write_safe_s(int fd, void *buf, size_t len);
+
+/**
+ * First, read uint32_t as a message length, then read the rest of the message
+ * expecting given length. The exact length is returned in _len parameter.
+ */
+ssize_t sss_atomic_read_safe_s(int fd, void *buf, size_t max_len, size_t *_len);
+
+#endif /* __SSSD_ATOMIC_IO_H__ */