Class ScopedRetainer<Scope>

Example

import {ScopedRetainer, sleep} from "lifecycle-utils";

const retainer = new ScopedRetainer<[clientId: string]>();

async function useClient(clientId: string) {
    using handle = retainer.tryRetain([clientId], () => new Error(clientId + " is draining"));

    console.log("using " + clientId);
    await sleep(1000);
    console.log("done using " + clientId);
}

async function drainClient(clientId: string) {
    console.log("awaiting drain for " + clientId);
    using drain = await retainer.acquireDrain([clientId]);

    // no retained usages for this client are active while the drain handle is held
    console.log("drain started for " + clientId);
    await sleep(1000);
}

const usePromise = useClient("client1");
const drainPromise = drainClient("client1");

await useClient("client1").catch(console.log);
await useClient("client2");
await Promise.all([usePromise, drainPromise]);

// using client1
// awaiting drain for client1
// Error: client1 is draining
// using client2
// done using client1
// drain started for client1
// done using client2
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