Activity for selecting a resource for a subsequent seize/release or setting its parameters (capacity or queue size).

select(.trj, resources, policy = c("shortest-queue",
  "shortest-queue-available", "round-robin", "round-robin-available",
  "first-available", "random", "random-available"), id = 0)



the trajectory object.


one or more resource names, or a callable object (a function) which must return one or more resource names.


if resources is a character vector, this parameter determines the criteria for selecting a resource among the set of policies available (see details).


selection identifier for nested usage.


Returns the trajectory object.


The 'shortest-queue' policy selects the least busy resource; 'round-robin' selects resources in cyclical order; 'first-available' selects the first resource available, and 'random' selects a resource randomly.

All the 'available'-ending policies ('first-available', but also 'shortest-queue-available', 'round-robin-available' and 'random-available') check for resource availability (i.e., whether the capacity is non-zero), and exclude from the selection procedure those resources with capacity set to zero. This means that, for these policies, an error will be raised if all resources are unavailable.

See also