1. A non-transient, computer-readable storage medium storing program instruction executable by a processor to implement: a concurrent multi-lane bag data structure comprising: a plurality of independently-accessible concurrent intermediaries configured to store data elements; an insert function executable to insert a given data element into the bag by selecting one of the intermediaries and inserting the data element into the selected intermediary; and a consume function executable to consume a data element from the bag by choosing one of the intermediaries and removing and returning the data element from the chosen intermediary; wherein: the bag guarantees that an execution of the consume function consumes a data element if the bag is non-empty; and the bag enables multiple threads to execute the insert function or the consume function concurrently.