Module Async_unix__Unix_syscalls.Socket
module Address : sig ... end
module Family : sig ... end
type (+'a, 'b) t
constraint 'a = [< `Unconnected | `Bound | `Passive | `Active ] constraint 'b = [< Address.t ]
Sockets have a phantom type parameter that tracks the state of the socket in order to eliminate certain errors in which socket functions are called in the wrong order. Initially, a socket is
`Unconnected
. As various socket functions are called, they return a socket with a new phantom state. Here is a chart of the allowed state transitions.Unconnected ---connect--> Active | | ---bind--> Bound ---listen--> Passive ---accept---> Active | | ---connect--> Active
val sexp_of_t : ('a -> Ppx_sexp_conv_lib.Sexp.t) -> ('b -> Ppx_sexp_conv_lib.Sexp.t) -> ('a, 'b) t -> Ppx_sexp_conv_lib.Sexp.t
module Type : sig ... end
val create : 'addr Type.t -> ([ `Unconnected ], 'addr) t
val connect : ([< `Unconnected | `Bound ], 'addr) t -> 'addr -> ([ `Active ], 'addr) t Async_unix__.Import.Deferred.t
val connect_interruptible : ([< `Unconnected | `Bound ], 'addr) t -> 'addr -> interrupt:unit Async_unix__.Import.Deferred.t -> [ `Ok of ([ `Active ], 'addr) t | `Interrupted ] Async_unix__.Import.Deferred.t
val bind : ?reuseaddr:bool -> ([ `Unconnected ], 'addr) t -> 'addr -> ([ `Bound ], 'addr) t Async_unix__.Import.Deferred.t
bind socket addr
sets close_on_exec for the fd ofsocket
.
val bind_inet : ?reuseaddr:bool -> ([ `Unconnected ], Address.Inet.t) t -> Address.Inet.t -> ([ `Bound ], Address.Inet.t) t
bind_inet socket addr
is just likebind
but is restricted toInet.t
addresses and is therefore guaranteed not to block.
val listen : ?backlog:int -> ([ `Bound ], 'addr) t -> ([ `Passive ], 'addr) t
val accept : ([ `Passive ], 'addr) t -> [ `Ok of ([ `Active ], 'addr) t * 'addr | `Socket_closed ] Async_unix__.Import.Deferred.t
val accept_interruptible : ([ `Passive ], 'addr) t -> interrupt:unit Async_unix__.Import.Deferred.t -> [ `Ok of ([ `Active ], 'addr) t * 'addr | `Socket_closed | `Interrupted ] Async_unix__.Import.Deferred.t
val accept_at_most : ([ `Passive ], 'addr) t -> limit:int -> [ `Ok of (([ `Active ], 'addr) t * 'addr) list | `Socket_closed ] Async_unix__.Import.Deferred.t
accept_at_most
is likeaccept
, but will return up tolimit
connections before yielding, wherelimit >= 1
.accept_at_most
first waits for one connection and then attempts to retrieve up tolimit
connections through non-blockingUnix
.accept calls. If a call toUnix
.accept would block beforelimit
is reached,accept_at_most
returns the connections retrieved thus far.Servers that must service a large number of connections tend to observe a stall in connection accept rates when under heavy load. Increasing
limit
will ameliorate this effect, and increase accept rates and overall throughput of the server at the cost of increased contention for resources amongst connections.For details, see:
Acceptable strategies for improving web server performance Brecht, Pariag, and Gammo. USENIX ATEC '04
val accept_at_most_interruptible : ([ `Passive ], 'addr) t -> limit:int -> interrupt:unit Async_unix__.Import.Deferred.t -> [ `Ok of (([ `Active ], 'addr) t * 'addr) list | `Socket_closed | `Interrupted ] Async_unix__.Import.Deferred.t
val shutdown : ('a, 'addr) t -> [ `Receive | `Send | `Both ] -> unit
val fd : ('a, 'addr) t -> Async_unix.Fd.t
val of_fd : Async_unix.Fd.t -> 'addr Type.t -> ('a, 'addr) t
val getsockname : ('a, 'addr) t -> 'addr
val getpeername : ('a, 'addr) t -> 'addr
module Opt : sig ... end
val getopt : ('a, 'addr) t -> 'c Opt.t -> 'c
val setopt : ('a, 'addr) t -> 'c Opt.t -> 'c -> unit
val mcast_join : ?ifname:string -> ?source:Inet_addr.t -> ('a, 'addr) t -> 'addr -> unit
val mcast_leave : ?ifname:string -> ?source:Inet_addr.t -> ('a, 'addr) t -> 'addr -> unit
val bind_to_interface_exn : (([ `Unconnected ], Address.t) t -> Linux_ext.Bound_to_interface.t -> unit) Core.Or_error.t
bind_to_interface_exn t (`Interface_name "eth0")
restricts messages from being received or sent on interfaces other thaneth0
. SeeLinux_ext.bind_to_interface
.Typically, one would use this function for very specific non-multicast requirements. For similar functionality when using multicast, see
Core_unix
.mcast_set_ifname.