Protected Objects - eggshell model

[hesobreira <herrsobreira@gmail.com>]

This was not clear to me while reading Barnes' book about protected
types.

There are two conditions that must be satisfied in order to execute
the entry call: no other task accessing the object at the same time
and the condition barrier evaluated to TRUE (eggshell, or two level
protection model). My question is: which one of these conditions is
evaluated first, the access lock or the condition barrier?

Thank you all in advance,
Hugo