Tcl Interpreters

The Tcl interpreters for a virtual server are linked together in an interpreter group. This capability simplifies maintaining state in the single address space of the multi-threaded AOLserver. The interpreter group shares:

global variables

C commands

Tcl scripts

open files

Tcl command traces

Tcl math function table

Each connection thread that requires Tcl will create a small interpreter which joins the interpreter group instead of waiting for an idle interpreter.

The AutoClose parameter, which is on by default, will close all non-shared files opened by an individual interpreter in the group when Ns_TclDeAllocateInterp is invoked. (Other interpreters in the group are not affected.) Ns_TclDeAllocateInterp is called after each Tcl request procedure.

It is recommended that you leave the AutoClose parameter set to on and share files between interpreters.