== SHOWSTOPPERS ==

== HIGH PRIORITY ==
[ ] Cache getaddrinfo responses
[ ] Replace Conn_X with Conn_get_socket_X!
[ ] Use shutdown(2) before closing connection (http://www.developerweb.net/forum/archive/index.php/t-2940.html).
[ ] Switch all pointers to callbacks to a single callback with paramenters +
	a flag that will say for what type of callbacks to call the callback.
[ ] Conn.c:532:19: warning: variable 'psa' set but not used [-Wunused-but-set-variable] & Co.
[ ] 

== LOW PRIORITY ==
[ ] How should wpool will be used?
	C = Conn_alloc();
	Conn_set_socket_domain(C, PF_INET);
	Conn_set_socket_type(C, SOCK_STREAM);
	Conn_set_socket_bind_addr(C, "127.0.0.1");
	Conn_set_socket_bind_port(C, 60000);
	Conn_commit(C);
	Conn_poll();
		epoll_wait
		accept
		w = choose a worker
		epoll_ctl(w->epoll_fd, new_fd);
		somehow enqueue 'accept' trigger

[ ] See http://highscalability.com/blog/2012/9/10/russ-10-ingredient-recipe-for-making-1-million-tps-on-5k-har.html
[ ] Dump all memory statistics
[ ] SCTP
[ ] .error_state -> error_type
[ ] if (.error_state...) -> if (.state == CONN_STATE_ERROR)
[ ] Audit CONN_STATE_EMPTY vs CONN_STATE_FREE
[ ] Add a function to set the maximum number of connections.
[ ] Fix the whole list scanning for expiration, band and closing.
[ ] Put callbacks in a structure to free some space from struct Conn.
[ ] wpool: When we free a Conn structure, we have to Conn_del_wp!
[ ] wpool: What if we add master sockets also to workers and do nothing in main
	thread? Check ma.c example. Verified: accept waks in only one thread.
	Still to check if epoll wakes in all threads! Seems it wakes all threads!
	Not very good.
[ ] Investigate splice.
[ ] Investigate MSG_MORE as an alternative to CORK or writev.
[ ] 

[ ] Check if we are swapping and warn.
[ ] Log faults and io.
[ ] We must have a single set of pointers to callback, not many. At Conn creation,
	we copy the default set and than replace, on request, some members.
	This will simplify the code.
[ ] Add access control
	Conn_ac_set_default(C, CONN_AC_DENY) - default deny (or CONN_AC_ALLOW)
	Conn_ac_add(C, CONN_AC_ALLOW, "2001::1/64"); - for ipv6
	Conn_ac_add(C, CONN_AC_ALLOW, "192.168.0.0/25"); - for ipv4
[ ] A la redir stuff

[ ] Bridge 2 connections together for proxy stuff.
[ ] Check PACKET: can we send with "send" without knowing the MAC?
[ ] UDP
[ ] Ce se intimpla daca se ajunge la ~ sfirsitul buffer-ului si nu pot inca sa
	procesez datele? We should log and close the connection. It is
	programmer's fault or a DoS.
[ ] Queue for delete/trytoconnect/etc.

Performance:
[ ] net.core.somaxconn
[ ]	Take care for /proc/net/netstat
[ ]	/proc/sys/net/ipv4/tcp_mem
	Now (512M): 49152 65536 98304
	Now (256M): 24576 32768 49152 - 55 conns/sec

	Test with: 80000 120000 240000 - 92 conns/sec
	Test with 160000 240000 480000 - 96 conns/sec

	After:
		echo "16000 64000 512000" > tcp_[rw]mem - 96

	After echo 1 > /proc/sys/net/ipv4/tcp_low_latency - 156 conns/sec

Pentru a reduce numarul de conexiuni in TIME-WAIT:
	echo 200 > /proc/sys/net/ipv4/tcp_max_tw_buckets

[ ] Add loadbalancing and failover in the base code.
[ ] Automaticaly put \0 at the end of receive data. What for?!
[ ] Add the possibility to wait for an char/string before calling recv callback.
	Maybe do this with socket filtering or in kernel?
[ ] Change socket buffer accordingly with user settings to minimize
	needed memory.

[ ] Dump how many memory is in use vor various parts of the internal data.
[ ] Do not mix slot and id and fd in examples.
[ ] Test suite
[ ] Free memory when the number of connections is going down.
[ ] Bandwidth part should have a separate pointer, to not load too much Conn structure.
[ ] Maybe we should have Bandwidth classes so we can group connections.
[ ] http://www.erlang-solutions.com/thesis/tcp_optimisation/tcp_optimisation.html
[ ] 

=== When we switch to Conn version 2 library ===
[ ] Conn_socket will cann Conn_socket_proto
[ ] use enums!
[ ] All internal variables of Conn structure must not be exposed directly.
[ ] http://urbanairship.com/blog/2010/09/29/linux-kernel-tuning-for-c500k/
[ ]