At 904, the TidalTree is searched for continuations that are ready to run, and one is selected for the hyperthread to resume. In various embodiments, the TidalTree is searched from the leaf-level, upward, and a cost function is used to determine which continuation to assign to the hyperthread. As one example, when a hyperthread becomes available, the continuation that has been queued for the longest amount of time could be assigned. If no continuations are waiting at the leaf level, or are outside a threshold specified by a cost function, a search will be performed up the TidalTree (e.g., the core level, then the socket level, and then the node level) for an appropriate continuation to assign to the hyperthread. If no appropriate continuations are found for the hyperthread to resume at the node level, the hyper-kernel for that node contacts the root. One typical reason for no continuations to be found at the node level is that there is not enough work for that node to be fully utilized. In some embodiments, the node or a subset of the node can enter an energy conserving state.
Time Sequence
For expository purposes, in the example, a “swapping” operation is used to transfer continuations and memory, but in fact that's not necessary in all embodiments.