Developer Guide and Reference

ID 767251
Date 10/31/2024
Public
Document Table of Contents

ATOMIC_FETCH_XOR

Atomic Intrinsic Subroutine (Generic): Performs atomic fetch and bitwise exclusive OR.

CALL ATOMIC_FETCH_XOR (atom, value, old [, stat])

atom

(Input; output) Must be a scalar coarray or coindexed object and of type integer with kind ATOMIC_INT_KIND. It becomes defined with the value of ieor (atom, int (value, ATOMIC_INT_KIND)) if no error occurs. Otherwise, it becomes undefined.

ATOMIC_INT_KIND is a named constant in the intrinsic module ISO_FORTRAN_ENV.

value

(Input) Must be a scalar integer. The value of value must be representable as an integer with kind ATOMIC_INT_KIND.

old

(Output) Must be a scalar of the same type as atom. It becomes undefined if an error occurs. Otherwise, it becomes defined with the value atom has at the beginning of the atomic operation.

stat

(Output; optional) Must be a non-coindexed integer scalar with a decimal exponent range of at least four (KIND=2 or greater). The value assigned to stat is specified in Overview of Atomic Subroutines. If stat is not present and an error condition occurs, error termination is initiated.

Example

Consider the following:

CALL ATOMIC_FETCH_XOR (N[4], 9, M) 

If the value of N on image 4 was 10 when the atomic operation is initiated, N on image 4 is defined with the value 3, and M is defined with the value 10 when the operation completes and no error occurs during the subroutine reference.