Cell Death

If the number of tokens in this store falls below a particular threshold (defined by the global parameter ets_lower_threshold, described in Section 4.8), the cell dies. Additionally, when the maximum number of cells allowed in the system (as defined by the parameter max_cells_per_process) has been reached, the processor will kill off a number of cells which have the smallest number of stored energy tokens,^4.9 in order to make room for new cells. It is therefore essential that a cell maintains a reasonable level of energy tokens in its store. (There is one other way in which a cell may die--it can terminate itself by executing the kill instruction.)

When a cell dies, any energy tokens remaining in its Energy Token Store are distributed to the local environment. More information about energy tokens is given in Section 4.5.2.