Camber.owner: def of bend-kit-camber@0.15.0.1
Import: import bend-kit-camber@0.15.0.1/camber.bend as Camber
Lines 260-310 of bend-kit-camber@0.15.0.1/camber.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-camber@0.15.0.1/camber.bend&start_line=260&end_line=310

import Base

# Only idle close ends this loop. Busy close never waits on a stalled handler.
# @unsafe is solely the lifecycle receive loop, not a termination/proof claim.
@unsafe def owner(~R: Type, ~P: Data, ~I: Data, ~E: Data, ~O: Data,
  ~handler: R -> P -> I -> IO(R & Result<&2, &2, E, O>), ~destroy: R -> IO(Unit),
  +messages: Chan(Message<R, P, I, E, O>), +room: U32, step: OwnerStep<R, P, I, E, O>
) -> IO(Unit):
  match step:
    case Waiting{resources, ledger}:
      do IO<Unit>:
        message : Message<R, P, I, E, O> <- receive(Message<R, P, I, E, O>, messages)
        owner(~R, ~P, ~I, ~E, ~O, ~handler, ~destroy, messages, room, Received{message, ledger, resources})
    case Counted{reply, counted, resources}:
      (counts, kept) = counted
      do IO<Unit>:
        sent : Result<&1, &1, Counts, Unit> <- Chan.send(Counts, reply, counts)
        owner(~R, ~P, ~I, ~E, ~O, ~handler, ~destroy, messages, room, Waiting{resources, kept})
    case Closing{reply, counted, resources}:
      (counts, kept) = counted
      Counts{+capacity, in_use, +completed, +rejected} = counts
      match in_use:
        case 0n:
          do IO<Unit>:
            dispose(~R, ~destroy, resources)
            Chan.close(Message<R, P, I, E, O>, messages)
            sent : Result<&1, &1, CloseResult, Unit> <- Chan.send(CloseResult, reply, Closed{})
            drain(~R, ~P, ~I, ~E, ~O, ~destroy, U32.to_nat(room), messages)
        case 1n+p:
          do IO<Unit>:
            sent : Result<&1, &1, CloseResult, Unit> <- Chan.send(CloseResult, reply, Busy{Counts{capacity, 1n+p, completed, rejected}})
            owner(~R, ~P, ~I, ~E, ~O, ~handler, ~destroy, messages, room, Waiting{resources, kept})
    case Received{message, ledger, resources}:
      match message:
        case Returned{resource}:
          do IO<Unit>:
            given : Ledger <- ledger.must(ledger.give(ledger), "camber: a resource returned without a matching submit")
            owner(~R, ~P, ~I, ~E, ~O, ~handler, ~destroy, messages, room, Waiting{resource <> resources, given})
        case Inspect{reply}:
          owner(~R, ~P, ~I, ~E, ~O, ~handler, ~destroy, messages, room, Counted{reply, ledger.counts(ledger), resources})
        case Shutdown{reply}:
          owner(~R, ~P, ~I, ~E, ~O, ~handler, ~destroy, messages, room, Closing{reply, ledger.counts(ledger), resources})
        case Submit{principal, input, reply}:
          match resources:
            case Nil{}:
              do IO<Unit>:
                sent : Result<&1, &1, Outcome<E, O>, Unit> <- Chan.send(Outcome<E, O>, reply, Exhausted{})
                owner(~R, ~P, ~I, ~E, ~O, ~handler, ~destroy, messages, room, Waiting{Nil{}, ledger.refuse(ledger)})
            case Con{resource, rest}:
              do IO<Unit>:
                lent : Ledger <- ledger.must(ledger.lend(ledger), "camber: a held resource found no free pool unit")
                IO.spawn(Unit, work(~R, ~P, ~I, ~E, ~O, ~handler, ~destroy, resource, principal, input, messages, reply))
                owner(~R, ~P, ~I, ~E, ~O, ~handler, ~destroy, messages, room, Waiting{rest, lent})

Uses (29):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Chan
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Chan.close
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Chan.send
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=IO
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=IO.bind
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=IO.spawn
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Pair
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Result
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Sigma
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.to_nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Unit
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=CloseResult
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=Counts
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=Ledger
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=Message
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=Outcome
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=OwnerStep
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=dispose
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=drain
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=ledger.counts
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=ledger.give
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=ledger.lend
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=ledger.must
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=ledger.refuse
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=receive
  https://jend.leeeet.dev/definition.txt?path=bend-kit-camber@0.15.0.1/camber.bend&name=work