diff --git a/fd_manager.cpp b/fd_manager.cpp
new file mode 100644
index 0000000..67d75bd
--- /dev/null
+++ b/fd_manager.cpp
@@ -0,0 +1,63 @@
+/*
+ * fd_manager.cpp
+ *
+ *  Created on: Sep 25, 2017
+ *      Author: root
+ */
+
+
+#include "fd_manager.h"
+int fd_manager_t::fd_exist(int fd)
+{
+	return fd_to_fd64_mp.find(fd)!=fd_to_fd64_mp.end();
+}
+int fd_manager_t::exist(fd64_t fd64)
+{
+	return fd64_to_fd_mp.find(fd64)!=fd64_to_fd_mp.end();
+}
+int fd_manager_t::to_fd(fd64_t fd64)
+{
+	assert(exist(fd64));
+	return fd64_to_fd_mp[fd64];
+}
+void fd_manager_t::fd64_close(fd64_t fd64)
+{
+	assert(exist(fd64));
+	int fd=fd64_to_fd_mp[fd64];
+	fd64_to_fd_mp.erase(fd64);
+	fd_to_fd64_mp.erase(fd);
+	if(exist_info(fd64))
+	{
+		fd_info_mp.erase(fd64);
+	}
+	assert(close(fd)==0);
+}
+void fd_manager_t::reserve(int n)
+{
+	fd_to_fd64_mp.reserve(n);
+	fd64_to_fd_mp.reserve(n);
+	fd_info_mp.reserve(n);
+}
+u64_t fd_manager_t::create(int fd)
+{
+	assert(!fd_exist(fd));
+	fd64_t fd64=counter++;
+	fd_to_fd64_mp[fd]=fd64;
+	fd64_to_fd_mp[fd64]=fd;
+	return fd64;
+}
+fd_manager_t::fd_manager_t()
+{
+	counter=u32_t(-1);
+	counter+=100;
+	reserve(10007);
+}
+fd_info_t & fd_manager_t::get_info(fd64_t fd64)
+{
+	assert(exist(fd64));
+	return fd_info_mp[fd64];
+}
+int fd_manager_t::exist_info(fd64_t fd64)
+{
+	return fd_info_mp.find(fd64)!=fd_info_mp.end();
+}
diff --git a/fd_manager.h b/fd_manager.h
new file mode 100644
index 0000000..20cea91
--- /dev/null
+++ b/fd_manager.h
@@ -0,0 +1,43 @@
+/*
+ * fd_manager.h
+ *
+ *  Created on: Sep 25, 2017
+ *      Author: root
+ */
+
+#ifndef FD_MANAGER_H_
+#define FD_MANAGER_H_
+
+#include "common.h"
+//#include "packet.h"
+#include "connection.h"
+
+struct fd_info_t
+{
+	//ip_port_t ip_port;
+	conn_info_t *p_conn_info;
+};
+
+struct fd_manager_t   //conver fd to a uniq 64bit number,avoid fd value conflict caused by close and re-create
+//this class is not strictly necessary,it just makes epoll fd handling easier
+{
+	fd_info_t & get_info(fd64_t fd64);
+	int exist_info(fd64_t);
+	int exist(fd64_t fd64);
+	int to_fd(fd64_t);
+	void fd64_close(fd64_t fd64);
+	void reserve(int n);
+	u64_t create(int fd);
+	fd_manager_t();
+private:
+	u64_t counter;
+	unordered_map<int,fd64_t> fd_to_fd64_mp;
+	unordered_map<fd64_t,int> fd64_to_fd_mp;
+	unordered_map<fd64_t,fd_info_t> fd_info_mp;
+	int fd_exist(int fd);
+	//void remove_fd(int fd);
+	//fd64_t fd_to_fd64(int fd);
+};
+
+extern fd_manager_t fd_manager;
+#endif /* FD_MANAGER_H_ */