*jlinker-default-connection-pool*

This variable specifies the default parameters for a jlinker connection pool.

The initial value is nil to specify no connection pool (for compatibility with earlier versions where connection pooling was not available).

A typical value is a list of the form

   (lisp-min lisp-max lisp-idle java-min java-max java-idle)

where

• lisp-min is the minimum number of connection pool ports from Lisp to Java
• lisp-max is the maximum number of connection pool ports from Lisp to Java
• lisp-idle is the maximum idle time allowed for a port from Lisp to Java
• java-min is the minimum number of connection pool ports from Java to Lisp
• java-max is the maximum number of connection pool ports from Java to Lisp
• java-idle is the maximum idle time allowed for a port from Java to Lisp

All values are positive integers, 0 or -1 (see below for the meanings of 0 and -1).

This list can be abbreviated by the following shorter forms:

;;  A single number n denotes the list 

   (h n 0 h n 0)

;; where h == (ceiling n 2)

;; A 2-element list (a b) denotes the list 

  (h a 0 k b 0)

;; where h == (ceiling a 2) and k = (ceiling b 2)

The effective connection pool parameters are determined by comparing this list with a corresponding list from the Java side. The comparison is made using the following rules:

• A -1 value in any position means to use the value from the other side.
• If both values are positive, use the minimum.
• If the effective value of lisp-min or java-min is zero, connection pooling is disabled.
• If both mins or maxes are -1 (meaning use the value from the other side), use the value 1.
• If both idle values are -1, use the value 0.
• If a max value is less than a min value, an error is signaled. (So if both maxes are -1 and both mins are greater than 1, an error will result since both maxes will be set to 1 which is less than the min values).
• An idle value of zero denotes an indefinite period.

Each port from Lisp to Java represents a socket connection in Lisp and a thread in Java.

Each port from Java to Lisp represents a socket connection In Java and a thread (Lisp process) in Lisp.

Ports up to the minimum number are created during jlinker initialization (but after jlinker-init returns). Ports above the minumum number are created on demand. The idle times apply to ports above the minimum number; if one such port is idle for the specified time, it is closed and the associated thread ended.

See jlinker.htm for more information on the jLinker facility.

Copyright (c) 1998-2022, Franz Inc. Lafayette, CA., USA. All rights reserved.
This page was not revised from the 10.0 page.
Created 2019.8.20.