Run a function on each work item via a pool of persistent callr sessions
Source:R/callr_pool.R
callr_pool.RdCreates `n_workers` persistent [callr::r_session] workers, loads the swereg namespace once per worker, then dispatches items across workers as they become idle. This avoids the per-item startup cost of [callr::r_bg()].
Usage
callr_pool(
items,
worker_fn,
n_workers,
swereg_dev_path = NULL,
p = NULL,
item_labels = NULL,
collect = TRUE,
timeout_minutes = 30
)Arguments
- items
List of argument lists, one per work item. Each element is passed to `worker_fn` via [do.call()].
- worker_fn
Function to call in each subprocess. Its signature must match the names in each element of `items`.
- n_workers
Integer number of concurrent subprocesses.
- swereg_dev_path
Path to local swereg dev copy (for `devtools::load_all()`), or `NULL` to use installed swereg.
- p
Progressor function from [progressr::progressor()], or `NULL`.
- item_labels
Character vector of labels for error messages (same length as `items`). Defaults to `"1"`, `"2"`, etc.
- collect
If `TRUE` (default), collect and return worker results. If `FALSE`, discard results (useful when workers save output directly).
- timeout_minutes
Numeric. Maximum minutes a single work item may run before the worker is killed and respawned with the same item. A timed-out item is retried once; if it times out again, `callr_pool()` calls [stop()]. Set to `NULL` to disable. Default: 30.