In this article, we investigate a denotational semantics based on event structures for a very simple imperative and concurrent programming language. The model incorporates behaviours of weak memory models such as reordering of instructions and non-locality. Our model can then be used to define a function from programs to their possible outcomes that can be used to give a formal semantics to a processor or a programming language. Most of the semantic ideas come from game semantics and its recent development based on event structures, but taking advantage of the first-order setting, we present in this paper a self-contained simplification of these ideas.