miou 0.3.1 · OCaml Package

The Unix layer of Miou.

This module offers a re-implementation of the I/O according to Miou's model. This module is essentially concerned with reading and writing Unix.file_descr from sockets, pipes, fifos, terminals (and pseudo-terminals) and probably devices. For all these types of file_descr, reading/writing can block (waiting for bytes or waiting for the system's internal buffer to be free).

This is not generally the case for files and folders where read/write does not block. So, as far as files/folders are concerned, there is no point in using the suspend/resume mechanisms offered by Miou. These mechanisms (and the use of Unix.select) could actually degrade performance. It is therefore advisable to use the Unix module directly rather than Miou_unix for files/folders.

It should be noted, however, that reading/writing files can take a long time. So, in a cooperative context (with Miou.async), it may be worthwhile to increase the availability of other tasks to run with Miou.yield - so associate a Miou.yield with these operations. However, in the case of parallelization (Miou.call), it is not necessary to cooperate with the other tasks as they run in parallel. In this sense, and depending on the design of your application, these operations should, or should not, be associated with a Miou.yield.

type file_descr

Type of file-descriptors.

val of_file_descr : ?non_blocking:bool -> Unix.file_descr -> file_descr

of_file_descr ?non_blocking ?owner fd creates a new file_descr. Depending on non_blocking (defaults to true), we set the given fd to non-blocking mode or not.

val to_file_descr : file_descr -> Unix.file_descr

to_file_descr fd returns the real Unix.file_descr.

val tcpv4 : unit -> file_descr

tcpv4 () allocates a new IPv4 socket.

val tcpv6 : unit -> file_descr

tcpv6 () allocates a new IPv6 socket.

val bind_and_listen : 
  ?backlog:int ->
  ?reuseaddr:bool ->
  ?reuseport:bool ->
  file_descr ->
  Unix.sockaddr ->
  unit

bind_and_listen fd sockaddr binds the given socket to the given sockaddr and set up the given fd for receiving connection requests. backlog is the maximal number of pending requests. The optional argument reuseaddr (defaults to true) sets the REUSEADDR socket option on the given fd. The optional argument reuseport (defaults to true sets the REUSEPORT socket option on the given fd.

val accept : ?cloexec:bool -> file_descr -> file_descr * Unix.sockaddr

accept ?cloexec fd is a Miou friendly Unix.accept which returns file descriptors in non-blocking mode.

val connect : file_descr -> Unix.sockaddr -> unit

connect fd sockaddr is a Miou friendly Unix.connect. The function accepts only file_descrs in non-blocking mode.

val read : file_descr -> ?off:int -> ?len:int -> bytes -> int

read fd buf ~off ~len reads up to len bytes (defaults to Bytes.length buf - off from the given file-descriptor fd, storing them in byte sequence buf, starting at position off in buf (defaults to 0). It returns the actual number of characters read, between 0 and len (inclusive).

raises Unix.Unix_error
raised by the system call Unix.read. The function handles Unix.EINTR, Unix.EAGAIN and Unix.EWOULDBLOCK exceptions and redo the system call.

raises Invalid_argument
if off and len do not designate a valid range of buf

val really_read : file_descr -> ?off:int -> ?len:int -> bytes -> unit

really_read fd buf ~off ~len reads len bytes (defaults to Bytes.length buf - off) from the given file-descriptor fd, storing them in byte sequence buf, starting at position off in buf (defaults to 0). If len = 0, really_read does nothing.

raises Unix.Unix_error
raised by the system call Unix.read. The function handles Unix.EINTR, Unix.EAGAIN and Unix.EWOULDBLOCK exceptions and redo the system call.

raises End_of_file
if Unix.read returns 0 before len characters have been read.

raises Invalid_argument
if off and len do not designate a valid range of buf

val write : file_descr -> ?off:int -> ?len:int -> string -> unit

write fd str ~off ~len writes len bytes (defaults to String.length str - off) from byte sequence buf, starting at offset off (defaults to 0), to the given file-descriptor fd.

raises Unix.Unix_error
raised by the system call Unix.read. The function handles Unix.EINTR, Unix.EAGAIN and Unix.EWOULDBLOCK exceptions and redo the system call.

raises Invalid_argument
if off and len do not designate a valid range of buf

val close : file_descr -> unit

close fd closes properly the given fd.

val sleep : float -> unit

sleep v suspends the current task and sleeps v seconds.

val run : ?g:Stdlib.Random.State.t -> ?domains:int -> (unit -> 'a) -> 'a

module Ownership : sig ... end

val blocking_read : Unix.file_descr -> unit

val blocking_write : Unix.file_descr -> unit

package miou

The Unix layer of Miou.