Derived Types in the ISO_FORTRAN_ENV Module

EVENT_TYPE

This is a derived type with private components. It is an extensible type with no type parameters. Each component that is nonallocatable is initialized by default.

A scalar variable of type EVENT_TYPE is an event variable. The value of an event variable contains its event count, which is modified by a sequence of EVENT POST and EVENT WAIT statements. A modification to the event count is as if the intrinsic ATOMIC_ADD were executed with a variable that stores the count as its ATOM argument.

A coarray that is of type EVENT_TYPE can be referenced or defined during execution of a segment that is unordered relative to the execution of another segment in which that coarray is defined. The event count is an integer of ATOMIC_INT_KIND. The initial value of the event count of a variable of type EVENT_TYPE is zero.

A named entity with declared type EVENT_TYPE, or which has a noncoarray potential subobject component with declared type EVENT_TYPE, must be a variable. A component with type EVENT_TYPE must be a data component.

A named variable with declared type EVENT_TYPE must be a coarray. A named variable with a noncoarray potential subobject component of type EVENT TYPE must be a coarray.

An event variable must not appear in a variable-definition context except as the event-var argument in an EVENT POST or EVENT WAIT statement, as an allocatable object, or as an actual argument in a reference to a procedure with an explicit interface if the corresponding dummy argument has INTENT(INOUT).

A variable with a nonpointer subobject of type EVENT_TYPE must not appear in a variable-definition context except as an allocatable object in an ALLOCATE statement without a SOURCE= specifier, as an allocatable object in a DEALLOCATE statement, or as an actual argument in a reference to a procedure with an explicit interface if the corresponding dummy argument has INTENT(INOUT).

If EXTENDS appears in a TYPE statement and the type being defined has a potential subobject component of type EVENT_TYPE, its parent type must be EVENT_TYPE or LOCK_TYPE, or have a potential subobject component of type EVENT_TYPE or LOCK_TYPE.

LOCK_TYPE

This is a derived type with private components; none of the components can be allocatable or a pointer. It is an extensible type with no type parameters. It does not have the BIND (C) attribute or type parameters, and is not a sequence type. All components have default initialization.

A scalar variable of type LOCK_TYPE is a lock variable. A lock variable can have one of two states: locked or unlocked. The unlocked state is represented by the one value that is the initial value of a LOCK_TYPE variable. The locked state is represented by all other values. The value of a lock variable can be changed with the LOCK and UNLOCK statements.

A named variable of type LOCK_TYPE must be a coarray. A named variable with a noncoarray sub-component of type LOCK_TYPE must also be a coarray.

A named constant can not be of type LOCK_TYPE, nor can it have a noncoarrray potential subobject component with a declared LOCK_TYPE.

If EXTENDS appears in TYPE statement and the type being defined has a potential subobject component of type LOCK_TYPE, its parent type must be EVENT_TYPE or LOCK_TYPE, or have a potential subobject component of type EVENT_TYPE or LOCK_TYPE.

A lock variable must not appear in a variable definition context except as the lock-variable in a LOCK or UNLOCK statement, as an allocatable object, or as an actual argument in a reference to a procedure with an explicit interface where the corresponding dummy argument has INTENT (INOUT).

A variable with a subobject of type LOCK_TYPE must not appear in a variable definition context except as an allocatable object or as an actual argument in a reference to a procedure with an explicit interface where the corresponding dummy argument has INTENT (INOUT).