Opportunistic Multitasking

Services for a personal electronic device are provided through which a form of background processing or multitasking is supported. The disclosed services permit user applications to take advantage of background processing without significant negative consequences to a user's experience of the foreground process or the personal electronic device's power resources. To effect the disclosed multitasking, one or more of a number of operational restrictions may be enforced. By way of example, an application that may normally be placed into the background state may instead be terminated if it controls a lock on a shared system resource.