A method, system and computer readable storage medium for executing a set of tasks. The method includes selecting an incomplete task in the set and then either starting its execution (if it was not previously suspended) or resuming its execution (if it was previously suspended). An execution timer is also started. If the selected task completes before expiry of the execution timer, the selection process is reinitiated; otherwise, the selected task is suspended, and the selection process is reinitiated. In this way, processing of a lengthy or lower-priority task can be pre-empted by processing of a shorter or higher-priority task. The method may also involve recognizing that a new version of an existing task already in the task set has been added thereto. In such a case, the older version is removed from the task set even if it is not yet complete.