Macros

Summary

Like decf and incf, but does the operation atomically.

Package

system

Signature

atomic-fixnum-decf place &optional fixnum-delta => new-value

atomic-fixnum-incf place &optional fixnum-delta => new-value

Arguments

place

One of the specific set of places defined for low level atomic operations.

fixnum-delta

A fixnum, default value 1

Values

new-value

A fixnum.

Description

The macro atomic-fixnum-decf is like decf (for fixnums only) and atomic-fixnum-incf is like incf (for fixnums only), except that they are guaranteed atomic for a suitable place.

place must be one of the places described in Low level atomic operations, or expand to one of them.

Both the value in the place and fixnum-delta must be fixnums. The arithmetic is done without checking for overflow.

See also

atomic-decf
atomic-incf
low-level-atomic-place-p