##-
# Author: Brian Tiffin
# Dedicated to the public domain
#
# Date: September, 2016
# Modified: 2016-11-22/05:35-0500
##+
#
# critical.icn, Demonstrate mutually exclusive expression control
#
global x

procedure main()
    x := 0

    mtx := mutex()
    T1 := thread report(mtx)
    T2 := thread other(mtx)

    # due to the nature of threading
    # the values displayed in report
    # might be 1,2,3,4 or 1,10,11,12 or 1,2,11,12 etc
    wait(T1 | T2)

    # final result will always be 12
    write("x is ", x)
end

# increment and report
procedure report(mtx)
    every 1 to 4 do {
        critical mtx : x := x + 1
        write(x)
    }
end

# just increment
procedure other(mtx)
    every 1 to 8 do
        critical mtx : x := x + 1
end