select {simmer} | R Documentation |
Select Resources
Description
Activity for selecting a resource for a subsequent seize/release or setting
its parameters (capacity or queue size). Resources must be defined in the
simulation environment (see add_resource
).
Usage
select(.trj, resources, policy = c("shortest-queue",
"shortest-queue-available", "round-robin", "round-robin-available",
"first-available", "random", "random-available"), id = 0, ..., tag)
Arguments
.trj |
the trajectory object. |
resources |
one or more resource names, or a callable object (a function) which must return one or more resource names. |
policy |
if |
id |
selection identifier for nested usage. |
... |
unused. |
tag |
activity tag name to perform named rollbacks (see
|
Details
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.
Value
Returns the trajectory object.
See Also
seize_selected
, release_selected
,
set_capacity_selected
, set_queue_size_selected
Examples
## predefined policy
traj <- trajectory() %>%
select(paste0("doctor", 1:3), "round-robin") %>%
seize_selected(1) %>%
timeout(5) %>%
release_selected(1)
simmer() %>%
add_resource("doctor1") %>%
add_resource("doctor2") %>%
add_resource("doctor3") %>%
add_generator("patient", traj, at(0, 1, 2)) %>%
run() %>%
get_mon_resources()
## custom policy
env <- simmer()
res <- paste0("doctor", 1:3)
traj <- trajectory() %>%
select(function() {
occ <- get_server_count(env, res) + get_queue_count(env, res)
res[which.min(occ)[1]]
}) %>%
seize_selected(1) %>%
timeout(5) %>%
release_selected(1)
for (i in res) env %>%
add_resource(i)
env %>%
add_generator("patient", traj, at(0, 1, 2)) %>%
run() %>%
get_mon_resources()