Commit 34cfa54a authored by henry's avatar henry
Browse files

fixup! TB 40933: Add tor-launcher functionality 

TB 41921: Ensure TorProviderBuilder.build can be called immediately
after TorProviderBuilder.init returns (without await).

We make sure that the `#provider` instance is created before any break
in execution caused by an `await`.
parent 4b7dc6cc

toolkit/components/tor-launcher/TorProviderBuilder.sys.mjs

+43 −16
Original line number Diff line number Diff line
@@ -54,14 +54,15 @@ export class TorProviderBuilder { 


  /**

   * Initialize the provider of choice.

   * Even though initialization is asynchronous, we do not expect the caller to

   * await this method. The reason is that any call to build() will wait the

   * initialization anyway (and re-throw any initialization error).

   */

  static async init() {

  static init() {

    switch (this.providerType) {

      case TorProviders.tor:

        await this.#initTorProvider();

        // Even though initialization of the initial TorProvider is

        // asynchronous, we do not expect the caller to await it. The reason is

        // that any call to build() will wait the initialization anyway (and

        // re-throw any initialization error).

        this.#initTorProvider();

        break;

      case TorProviders.none:

        lazy.TorLauncherUtil.setProxyConfiguration(
@@ -74,7 +75,12 @@ export class TorProviderBuilder { 
    }

  }



  static async #initTorProvider() {

  /**

   * Replace #provider with a new instance.

   *

   * @returns {Promise<TorProvider>} The new instance.

   */

  static #initTorProvider() {

    if (!this.#exitObserver) {

      this.#exitObserver = this.#torExited.bind(this);

      Services.obs.addObserver(
@@ -83,18 +89,39 @@ export class TorProviderBuilder { 
      );

    }



    // NOTE: We need to ensure that the #provider is set as soon

    // TorProviderBuilder.init is called.

    // I.e. it should be safe to call

    //   TorProviderBuilder.init();

    //   TorProviderBuilder.build();

    // without any await.

    //

    // Therefore, we await the oldProvider within the Promise rather than make

    // #initTorProvider async.

    //

    // In particular, this is needed by TorConnect when the user has selected

    // quickstart, in which case `TorConnect.init` will immediately request the

    // provider. See tor-browser#41921.

    this.#provider = this.#replaceTorProvider(this.#provider);

    return this.#provider;

  }



  /**

   * Replace a TorProvider instance. Resolves once the TorProvider is

   * initialised.

   *

   * @param {Promise<TorProvider>?} oldProvider - The previous's provider's

   *   promise, if any.

   * @returns {TorProvider} The new TorProvider instance.

   */

  static async #replaceTorProvider(oldProvider) {

    try {

      const old = await this.#provider;

      old?.uninit();

      // Uninitialise the old TorProvider, if there is any.

      (await oldProvider)?.uninit();

    } catch {}

    this.#provider = new Promise((resolve, reject) => {

    const provider = new lazy.TorProvider();

      provider

        .init()

        .then(() => resolve(provider))

        .catch(reject);

    });

    await this.#provider;

    await provider.init();

    return provider;

  }



  static uninit() {