Submit a Batch of Tasks

mizu_submit_batch() submits one task per element of .exprs in a single .Call: one R boundary crossing and one wake-up sweep per batch instead of per task. At target rates the call boundary is a first-order cost, so a burst submitted this way reaches the workers sooner than the same burst looped through mizu_submit(). Pair with mizu_collect_all() to batch the collection side too.

Usage

mizu_submit_batch(.pool, .exprs, ..., .timeout = Inf)

Arguments

.pool

a pool handle from mizu_pool() or mizu_pool_attach(); inside a task, the evaluating worker's own handle from mizu_current_pool().

.exprs

a list of expressions, one per task. Quote them yourself: elements of a list cannot be captured unevaluated.

...

named values bound in the evaluation environment. The values are serialized. mori::share()d objects reduce to identifiers and map zero-copy on the worker. The formals ahead of ... are dot-prefixed, so a name you pass through ... can never collide with them.

.timeout

seconds to wait for injection-ring space before the call raises mizu_error_submit_timeout. Submission blocks only when the ring is full (back-pressure) and returns immediately otherwise. Inf (the default) waits indefinitely; 0 does not wait.

Value

A list of task handles (class "mizu_task"), one per accepted task — shorter than .exprs when the ring filled past .timeout mid-batch.

Details

Each task's wire payload is the same list(.expr, args) as mizu_submit()'s, with the ... arguments shared by every task in the batch. Unlike mizu_submit(), expressions are not captured: the elements of .exprs are pre-quoted (or plain values, which evaluate to themselves).

Submission semantics per task are mizu_submit()'s, with one difference: if the injection ring fills past .timeout mid-batch, the call returns the handles accepted so far instead of raising mizu_error_submit_timeout. Fatal outcomes (pool stopped, result slots exhausted) still raise; tasks already submitted stay valid and collectible.

Examples

p <- mizu_pool()
ts <- mizu_submit_batch(p, list(quote(1 + 1), quote(2 + 2)))
mizu_collect_all(ts, timeout = 30)
#> [[1]]
#> [1] 2
#> 
#> [[2]]
#> [1] 4
#> 
mizu_pool_stop(p)