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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /services/settings/RemoteSettingsWorker.sys.mjs | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | services/settings/RemoteSettingsWorker.sys.mjs | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/services/settings/RemoteSettingsWorker.sys.mjs b/services/settings/RemoteSettingsWorker.sys.mjs new file mode 100644 index 0000000000..c08adbca98 --- /dev/null +++ b/services/settings/RemoteSettingsWorker.sys.mjs @@ -0,0 +1,238 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/** + * Interface to a dedicated thread handling for Remote Settings heavy operations. + */ +import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs"; + +import { setTimeout, clearTimeout } from "resource://gre/modules/Timer.sys.mjs"; + +const lazy = {}; + +XPCOMUtils.defineLazyPreferenceGetter( + lazy, + "gMaxIdleMilliseconds", + "services.settings.worker_idle_max_milliseconds", + 30 * 1000 // Default of 30 seconds. +); + +ChromeUtils.defineESModuleGetters(lazy, { + AsyncShutdown: "resource://gre/modules/AsyncShutdown.sys.mjs", +}); + +ChromeUtils.defineModuleGetter( + lazy, + "SharedUtils", + "resource://services-settings/SharedUtils.jsm" +); + +// Note: we currently only ever construct one instance of Worker. +// If it stops being a singleton, the AsyncShutdown code at the bottom +// of this file, as well as these globals, will need adjusting. +let gShutdown = false; +let gShutdownResolver = null; + +class RemoteSettingsWorkerError extends Error { + constructor(message) { + super(message); + this.name = "RemoteSettingsWorkerError"; + } +} + +class Worker { + constructor(source) { + if (gShutdown) { + console.error("Can't create worker once shutdown has started"); + } + this.source = source; + this.worker = null; + + this.callbacks = new Map(); + this.lastCallbackId = 0; + this.idleTimeoutId = null; + } + + async _execute(method, args = [], options = {}) { + // Check if we're shutting down. + if (gShutdown && method != "prepareShutdown") { + throw new RemoteSettingsWorkerError("Remote Settings has shut down."); + } + // Don't instantiate the worker to shut it down. + if (method == "prepareShutdown" && !this.worker) { + return null; + } + + const { mustComplete = false } = options; + // (Re)instantiate the worker if it was terminated. + if (!this.worker) { + this.worker = new ChromeWorker(this.source); + this.worker.onmessage = this._onWorkerMessage.bind(this); + this.worker.onerror = error => { + // Worker crashed. Reject each pending callback. + for (const { reject } of this.callbacks.values()) { + reject(error); + } + this.callbacks.clear(); + // And terminate it. + this.stop(); + }; + } + // New activity: reset the idle timer. + if (this.idleTimeoutId) { + clearTimeout(this.idleTimeoutId); + } + let identifier = method + "-"; + // Include the collection details in the importJSONDump case. + if (identifier == "importJSONDump-") { + identifier += `${args[0]}-${args[1]}-`; + } + return new Promise((resolve, reject) => { + const callbackId = `${identifier}${++this.lastCallbackId}`; + this.callbacks.set(callbackId, { resolve, reject, mustComplete }); + this.worker.postMessage({ callbackId, method, args }); + }); + } + + _onWorkerMessage(event) { + const { callbackId, result, error } = event.data; + // If we're shutting down, we may have already rejected this operation + // and removed its callback from our map: + if (!this.callbacks.has(callbackId)) { + return; + } + const { resolve, reject } = this.callbacks.get(callbackId); + if (error) { + reject(new RemoteSettingsWorkerError(error)); + } else { + resolve(result); + } + this.callbacks.delete(callbackId); + + // Terminate the worker when it's unused for some time. + // But don't terminate it if an operation is pending. + if (!this.callbacks.size) { + if (gShutdown) { + this.stop(); + if (gShutdownResolver) { + gShutdownResolver(); + } + } else { + this.idleTimeoutId = setTimeout(() => { + this.stop(); + }, lazy.gMaxIdleMilliseconds); + } + } + } + + /** + * Called at shutdown to abort anything the worker is doing that isn't + * critical. + */ + _abortCancelableRequests() { + // End all tasks that we can. + const callbackCopy = Array.from(this.callbacks.entries()); + const error = new Error("Shutdown, aborting read-only worker requests."); + for (const [id, { reject, mustComplete }] of callbackCopy) { + if (!mustComplete) { + this.callbacks.delete(id); + reject(error); + } + } + // There might be nothing left now: + if (!this.callbacks.size) { + this.stop(); + if (gShutdownResolver) { + gShutdownResolver(); + } + } + // If there was something left, we'll stop as soon as we get messages from + // those tasks, too. + // Let's hurry them along a bit: + this._execute("prepareShutdown"); + } + + stop() { + this.worker.terminate(); + this.worker = null; + this.idleTimeoutId = null; + } + + async canonicalStringify(localRecords, remoteRecords, timestamp) { + return this._execute("canonicalStringify", [ + localRecords, + remoteRecords, + timestamp, + ]); + } + + async importJSONDump(bucket, collection) { + return this._execute("importJSONDump", [bucket, collection], { + mustComplete: true, + }); + } + + async checkFileHash(filepath, size, hash) { + return this._execute("checkFileHash", [filepath, size, hash]); + } + + async checkContentHash(buffer, size, hash) { + // The implementation does little work on the current thread, so run the + // task on the current thread instead of the worker thread. + return lazy.SharedUtils.checkContentHash(buffer, size, hash); + } +} + +// Now, first add a shutdown blocker. If that fails, we must have +// shut down already. +// We're doing this here rather than in the Worker constructor because in +// principle having just 1 shutdown blocker for the entire file should be +// fine. If we ever start creating more than one Worker instance, this +// code will need adjusting to deal with that. +try { + lazy.AsyncShutdown.profileBeforeChange.addBlocker( + "Remote Settings profile-before-change", + async () => { + // First, indicate we've shut down. + gShutdown = true; + // Then, if we have no worker or no callbacks, we're done. + if ( + !RemoteSettingsWorker.worker || + !RemoteSettingsWorker.callbacks.size + ) { + return null; + } + // Otherwise, there's something left to do. Set up a promise: + let finishedPromise = new Promise(resolve => { + gShutdownResolver = resolve; + }); + + // Try to cancel most of the work: + RemoteSettingsWorker._abortCancelableRequests(); + + // Return a promise that the worker will resolve. + return finishedPromise; + }, + { + fetchState() { + const remainingCallbacks = RemoteSettingsWorker.callbacks; + const details = Array.from(remainingCallbacks.keys()).join(", "); + return `Remaining: ${remainingCallbacks.size} callbacks (${details}).`; + }, + } + ); +} catch (ex) { + console.error( + "Couldn't add shutdown blocker, assuming shutdown has started." + ); + console.error(ex); + // If AsyncShutdown throws, `profileBeforeChange` has already fired. Ignore it + // and mark shutdown. Constructing the worker will report an error and do + // nothing. + gShutdown = true; +} + +export var RemoteSettingsWorker = new Worker( + "resource://services-settings/RemoteSettingsWorker.js" +); |