Function

Summary

Sets a callback that is called when memory is exhausted in 64-bit LispWorks.

Package

system

Signature

set-memory-exhausted-callback function &optional where => callbacks

Arguments

function

A function designator, the keyword :reset , or nil .

where

:first , :last or nil .

Values

callbacks

A list of function designators.

Description

The function set-memory-exhausted-callback adds a callback that is called when memory is exhausted. That is, when the system fails to map memory.

Note: set-memory-check is a more robust way to protect against memory exhaustion problems.

If function is a function designator then it should be a function with signature

function gen-num size type-name static

function is expected to report what the system was trying to allocate when it failed to map memory. Its arguments are:

gen-num

The number of the generation in which it was trying to allocate.

size

The size in bytes which it was trying to allocate.

type-name

A string naming the allocation type it was trying to allocate.

static

A boolean, true if it was trying to allocate a static object, and false otherwise.

function can also have the special value :reset , which resets the callback list to nil .

function can also be nil , which means do nothing but simply return the current list of callbacks.

where defines the position in the list that the callback function is placed. Its allowed values are:

:first

function is placed first in the callbacks list.

:last

function is placed last in the callbacks list.

nil

function is removed from the callbacks list.

set-memory-exhausted-callback always first removes function from the callbacks list, and then adds it according to where . The default value of where is :first . Functions in the list are compared with equalp .

set-memory-exhausted-callback returns the callback list.

When a callback is called, Lisp already failed to map memory. This means that you must not rely on the callback to do real work. It should therefore attempt only a minimal amount of work such as clean-ups and generating debug information. It should not try to do real work.

After all the callbacks are called, the system signals an error of type storage-exhausted. The condition can be accessed using the accessors described for storage-exhausted.

Notes

set-memory-exhausted-callback is implemented only in 64-bit LispWorks. It is not relevant to the Memory Management API in 32-bit implementations.

See also

set-memory-check
storage-exhausted