8.104 EVENT_QUERY — Query whether a coarray event has occurred

Synopsis:

CALL EVENT_QUERY (EVENT, COUNT [, STAT])

Description:

EVENT_QUERY assigns the number of events to COUNT that have been posted to the EVENT variable and not yet been removed by calling EVENT WAIT. When STAT is present and the invocation is successful, it is assigned the value 0. If it is present and the invocation fails, it is assigned a positive value and COUNT is assigned the value -1.

Class:

subroutine

Arguments:
EVENT(intent(IN)) Scalar of type EVENT_TYPE, defined in ISO_FORTRAN_ENV; shall not be coindexed.
COUNT(intent(out))Scalar integer with at least the precision of default integer.
STAT(optional) Scalar default-kind integer variable.
Example:
program atomic
  use iso_fortran_env
  implicit none
  type(event_type) :: event_value_has_been_set[*]
  integer :: cnt
  if (this_image() == 1) then
    call event_query (event_value_has_been_set, cnt)
    if (cnt > 0) write(*,*) "Value has been set"
  elseif (this_image() == 2) then
    event post (event_value_has_been_set[1])
  end if
end program atomic
Standard:

TS 18508 or later