| Allegro CL version 10.1 Unrevised from 10.0 to 10.1. 10.0 version | ||||||||||
Arguments: &key name class reset-action run-reasons arrest-reasons priority quantum resume-hook suspend-hook initial-bindings run-immediately stack-allocation message-interrupt-function
This function returns a new process object, but does nothing about making it runnable.
name must be a string. Its default value is "Anonymous".
The class keyword argument specifies the class of
the process being created. The value defaults to the class mp:process. A subclass
of mp:process
may be specified instead, if a program has created such subclasses.
The default value of
quantum is 2 and of priority
is 0. run-reasons and
arrest-reasons are both lists of Lisp
objects. They default to nil (that is, the
empty list). The effect of these lists being empty or not is
described in multiprocessing.htm. The process can
run only if the arrest-reasons list is empty, and
the run-reasons list is not empty.
reset-action defaults to nil. If it is set to t, the
process will restart if it is reset or ever completes; that is, it
will once again apply its initial function to its initial
arguments. Otherwise, the process will be killed when it
completes.
There is no property-list keyword argument, but property lists for processes are supported and process-property-list accesses them. They can be modified in the usual property list way with getf and setf of getf and that function.
The initial-bindings,
resume-hook, and
suspend-hook arguments all default to nil and initialize the corresponding slot values of
the process object. The meanings of these slots are explained in
multiprocessing.htm.
The stack-allocation argument is only used in the :os-threads model of multiprocessing. It specifies the size to request from the OS for the thread associated with the new process. The default value is to copy the size used for the process in which the process-creating function (i.e. make-process or something that calls make-process) is running. A process's soft limit is set to a default value when the process starts. This value is 80% of the hard limit or 4 megabytes, whichever is less.
The message-interrupt-function argument is important for Windows only. In the windows environment only, it's very very bad to ignore messages for long periods of time. Some global events involve broadcasting messages to a class of threads, and some of these have to be responded to or things lock up.
To deal with this, each windows process has an attribute process-message-interrupt-function. When
a process is in a non-ready state (wait function, arrest reasons, no
run reasons), and a windows message appears on its message queue, then
the process-message-interrupt-function will be run
as if by process-interrupt call, if the
process-message-interrupt-function is non-nil.
The process-message-interrupt-function attribute
can be initialized at process creation via the
message-interrupt-function keyword argument. The
default value, if unspecified, is the value (at process-creation time)
of the variable mp:*default-message-interrupt-function*.
(mp:process-message-interrupt-function p) is setfable.
The function specified as the message-interrupt handler for a process
must return non-nil if there is any chance
that it made a change in Lisp state that could free another process to
run, and nil otherwise.
The system-provided initial value of *default-message-interrupt-function*
is the function mp::process-messages-in-interrupt, a function
of no arguments, that verifies the existance of messages on the queue.
It returns nil if there are none. Otherwise
it dispatches all of them and returns t.
The immigrant keyword argument is for internal use only. Do not specify a value for it.
The run-immediately keyword argument was designed to tell the in-Lisp scheduler to run the new process immediately (assuming it was runnable) regardless of the assigned priorities. It was never effective in threaded multiprocessing since scheduling was done by the OS. In 7.0 it is ignored and no value should be specified for it.
See multiprocessing.htm for general information on multiprocessing in Allegro CL.
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.
| Allegro CL version 10.1 Unrevised from 10.0 to 10.1. 10.0 version | ||||||||||