Shut down

Provides a way for users to gracefully shut down Glean, by blocking until it is finished performing pending tasks such as recording metrics and uploading pings.

How the Glean SDKs execute tasks

Most calls to Glean APIs are dispatched1. This strategy is adopted because most tasks performed by the Glean SDKs involve file system read or write operations, HTTP requests and other time consuming actions.

Each Glean SDK has an internal structure called "Dispatcher" which makes sure API calls get executed in the order they were called, while not requiring the caller to block on the completion of each of these tasks.

1

Here, this term indicates the tasks are run asynchronously in JavaScript or in a different thread for all other SDKs.

API

shutdown

fn main() {
    let cfg = Configuration {
        // ...
    };
    let client_info = /* ... */;
    glean::initialize(cfg, client_info);

    // Ensure the dispatcher thread winds down
    glean::shutdown();
}

import Glean from "@mozilla/glean/webext";

async function onUninstall() {
  // Flips Glean upload status to `false`,
  // which triggers sending of a `deletion-request` ping.
  Glean.setUploadEnabled(false);

  // Block on shut down to guarantee all pending pings
  // (including the `deletion-request` sent above)
  // are sent before the extension is uninstalled.
  await Glean.shutdown();

  // Uninstall browser extension without asking for user approval before doing so.
  await browser.management.uninstallSelf({ showConfirmDialog: false });
}

The shutdown API is available for all JavaScript targets, even though the above example is explicitly using the webext target.

Reference