nim-codex/codex/utils/trackedfutures.nim

47 lines
1020 B
Nim

import std/tables
import pkg/chronos
import ../logutils
{.push raises: [].}
type
TrackedFutures* = ref object
futures: Table[uint, FutureBase]
cancelling: bool
logScope:
topics = "trackable futures"
proc len*(self: TrackedFutures): int = self.futures.len
proc removeFuture(self: TrackedFutures, future: FutureBase) =
if not self.cancelling and not future.isNil:
self.futures.del(future.id)
proc track*[T](self: TrackedFutures, fut: Future[T]) =
if self.cancelling:
return
self.futures[fut.id] = FutureBase(fut)
proc cb(udata: pointer) =
self.removeFuture(fut)
fut.addCallback(cb)
proc cancelTracked*(self: TrackedFutures) {.async: (raises: []).} =
self.cancelling = true
trace "cancelling tracked futures"
var cancellations: seq[FutureBase]
for future in self.futures.values:
if not future.isNil and not future.finished:
cancellations.add future.cancelAndWait()
await noCancel allFutures cancellations
self.futures.clear()
self.cancelling = false