Other Library Functions

tcp-create-service

function

Library: TCP/IP client and server support (OMTCP legacy, OmniMark versions 6.0.2 - 7.0)
Include: omtcp.xin

Returns:


Declaration 
define external tcp-service function tcp-create-service
             at value integer PortNum           optional
     queue-size value integer ListenQueueSize   optional

or

define external tcp-service function tcp-create-service
     descriptor value integer ListenSocketDescriptor  optional
     queue-size value integer ListenQueueSize         optional

Argument definitions

PortNum
is the port the service is to be created on.
ListenSocketDescriptor
is a file descriptor for an already created socket.
ListenQueueSize
is the number of connection requests that will be queued for acceptance. The default value is 5.


Purpose

Use tcp-create-service in a server program to create a TCP service port to listen on for incoming service requests.

Requirements

You must include the following line at the beginning of your OmniMark program: 

  include "omtcp.xin"

You can specify either PortNum or the ListenSocketDescriptor, but not both (else external exception TCP22).

If ListenSocketDescriptor is specified it must be 0 or greater (else external exception TCP24).

If ListenQueueSize is specified it must be an integer from 1 to 1024 (else external exception TCP23).

Usage Notes

The maximum ListenQueueSize is operating system dependent. If the maximum queue size for a socket on your operating system is less than the value specified for ListenQueueSize, no exception will be thrown.

If PortNum is specified a listening socket descriptor is created at the specified port.

If neither PortNum or ListenSocketDescriptor is specified an available port is chosen. You can discover the number of this port using the tcp-port function.

If ListenSocketDescriptor is specified it is assumed to be a valid listening socket. This means that a socket was created using an external function library function prior to calling to tcp-create-service.

Example #1 


  local tcp-service DemoService
  
  set DemoService to tcp-create-service at 5600

Example #2 


  local tcp-service DemoService
  local integer port
  
  set DemoService to tcp-create-service
  set port to tcp-port DemoService
  output "The selected service port for omdemo-service is %d(port)%n"

Other Library Functions