nim-chronos/docs/examples/timeoutcomposed.nim

26 lines
713 B
Nim

## Single timeout for several operations
import chronos
proc shortTask {.async.} =
try:
await sleepAsync(1.seconds)
except CancelledError as exc:
echo "Short task was cancelled!"
raise exc # Propagate cancellation to the next operation
proc composedTimeout() {.async.} =
let
# Common timout for several sub-tasks
timeout = sleepAsync(10.seconds)
while not timeout.finished():
let task = shortTask() # Start a task but don't `await` it
if (await race(task, timeout)) == task:
echo "Ran one more task"
else:
# This cancellation may or may not happen as task might have finished
# right at the timeout!
task.cancelSoon()
waitFor composedTimeout()