diff options
Diffstat (limited to 'ext/timers/01_timers.js')
| -rw-r--r-- | ext/timers/01_timers.js | 727 |
1 files changed, 245 insertions, 482 deletions
diff --git a/ext/timers/01_timers.js b/ext/timers/01_timers.js index a92f9ab82..ee3d85661 100644 --- a/ext/timers/01_timers.js +++ b/ext/timers/01_timers.js @@ -4,23 +4,21 @@ ((window) => { const core = window.Deno.core; const { - ArrayPrototypeIndexOf, ArrayPrototypePush, ArrayPrototypeShift, - ArrayPrototypeSplice, - DateNow, Error, - FunctionPrototypeBind, + FunctionPrototypeCall, Map, MapPrototypeDelete, MapPrototypeGet, MapPrototypeHas, MapPrototypeSet, - MathMax, - Number, - String, + // deno-lint-ignore camelcase + NumberPOSITIVE_INFINITY, + PromisePrototypeThen, TypeError, } = window.__bootstrap.primordials; + const { webidl } = window.__bootstrap; // Shamelessly cribbed from extensions/fetch/11_streams.js class AssertionError extends Error { @@ -41,18 +39,6 @@ } } - function opStopGlobalTimer() { - core.opSync("op_global_timer_stop"); - } - - function opStartGlobalTimer(timeout) { - return core.opSync("op_global_timer_start", timeout); - } - - async function opWaitGlobalTimer() { - await core.opAsync("op_global_timer"); - } - function opNow() { return core.opSync("op_now"); } @@ -61,534 +47,311 @@ return core.opSync("op_sleep_sync", millis); } - // Derived from https://github.com/vadimg/js_bintrees. MIT Licensed. + // --------------------------------------------------------------------------- - class RBNode { - constructor(data) { - this.data = data; - this.left = null; - this.right = null; - this.red = true; - } + /** + * The task queue corresponding to the timer task source. + * + * @type { {action: () => void, nestingLevel: number}[] } + */ + const timerTasks = []; - getChild(dir) { - return dir ? this.right : this.left; - } + /** + * The current task's timer nesting level, or zero if we're not currently + * running a timer task (since the minimum nesting level is 1). + * + * @type {number} + */ + let timerNestingLevel = 0; - setChild(dir, val) { - if (dir) { - this.right = val; - } else { - this.left = val; - } + function handleTimerMacrotask() { + if (timerTasks.length === 0) { + return true; } - } - class RBTree { - #comparator = null; - #root = null; + const task = ArrayPrototypeShift(timerTasks); - constructor(comparator) { - this.#comparator = comparator; - this.#root = null; - } + timerNestingLevel = task.nestingLevel; - /** Returns `null` if tree is empty. */ - min() { - let res = this.#root; - if (res === null) { - return null; - } - while (res.left !== null) { - res = res.left; - } - return res.data; + try { + task.action(); + } finally { + timerNestingLevel = 0; } + return timerTasks.length === 0; + } - /** Returns node `data` if found, `null` otherwise. */ - find(data) { - let res = this.#root; - while (res !== null) { - const c = this.#comparator(data, res.data); - if (c === 0) { - return res.data; - } else { - res = res.getChild(c > 0); - } - } - return null; - } - - /** returns `true` if inserted, `false` if duplicate. */ - insert(data) { - let ret = false; - - if (this.#root === null) { - // empty tree - this.#root = new RBNode(data); - ret = true; - } else { - const head = new RBNode(null); // fake tree root - - let dir = 0; - let last = 0; - - // setup - let gp = null; // grandparent - let ggp = head; // grand-grand-parent - let p = null; // parent - let node = this.#root; - ggp.right = this.#root; - - // search down - while (true) { - if (node === null) { - // insert new node at the bottom - node = new RBNode(data); - p.setChild(dir, node); - ret = true; - } else if (isRed(node.left) && isRed(node.right)) { - // color flip - node.red = true; - node.left.red = false; - node.right.red = false; - } - - // fix red violation - if (isRed(node) && isRed(p)) { - const dir2 = ggp.right === gp; - - assert(gp); - if (node === p.getChild(last)) { - ggp.setChild(dir2, singleRotate(gp, !last)); - } else { - ggp.setChild(dir2, doubleRotate(gp, !last)); - } - } - - const cmp = this.#comparator(node.data, data); - - // stop if found - if (cmp === 0) { - break; - } - - last = dir; - dir = Number(cmp < 0); // Fix type + // --------------------------------------------------------------------------- - // update helpers - if (gp !== null) { - ggp = gp; - } - gp = p; - p = node; - node = node.getChild(dir); - } + /** + * The keys in this map correspond to the key ID's in the spec's map of active + * timers. The values are the timeout's cancel rid. + * + * @type {Map<number, number>} + */ + const activeTimers = new Map(); - // update root - this.#root = head.right; - } + let nextId = 1; - // make root black - this.#root.red = false; + /** + * @param {Function | string} callback + * @param {number} timeout + * @param {Array<any>} args + * @param {boolean} repeat + * @param {number | undefined} prevId + * @returns {number} The timer ID + */ + function initializeTimer( + callback, + timeout, + args, + repeat, + prevId, + ) { + // 2. If previousId was given, let id be previousId; otherwise, let + // previousId be an implementation-defined integer than is greater than zero + // and does not already exist in global's map of active timers. + let id; + let cancelRid; + if (prevId !== undefined) { + // `prevId` is only passed for follow-up calls on intervals + assert(repeat); + id = prevId; + cancelRid = MapPrototypeGet(activeTimers, id); + } else { + // TODO(@andreubotella): Deal with overflow. + // https://github.com/whatwg/html/issues/7358 + id = nextId++; + cancelRid = core.opSync("op_timer_handle"); - return ret; + // Step 4 in "run steps after a timeout". + MapPrototypeSet(activeTimers, id, cancelRid); } - /** Returns `true` if removed, `false` if not found. */ - remove(data) { - if (this.#root === null) { - return false; - } - - const head = new RBNode(null); // fake tree root - let node = head; - node.right = this.#root; - let p = null; // parent - let gp = null; // grand parent - let found = null; // found item - let dir = 1; - - while (node.getChild(dir) !== null) { - const last = dir; - - // update helpers - gp = p; - p = node; - node = node.getChild(dir); - - const cmp = this.#comparator(data, node.data); - - dir = cmp > 0; + // 3. If the surrounding agent's event loop's currently running task is a + // task that was created by this algorithm, then let nesting level be the + // task's timer nesting level. Otherwise, let nesting level be zero. + // 4. If timeout is less than 0, then set timeout to 0. + // 5. If nesting level is greater than 5, and timeout is less than 4, then + // set timeout to 4. + // + // The nesting level of 5 and minimum of 4 ms are spec-mandated magic + // constants. + if (timeout < 0) timeout = 0; + if (timerNestingLevel > 5 && timeout < 4) timeout = 4; + + // 9. Let task be a task that runs the following steps: + const task = { + action: () => { + // 1. If id does not exist in global's map of active timers, then abort + // these steps. + // + // This is relevant if the timer has been canceled after the sleep op + // resolves but before this task runs. + if (!MapPrototypeHas(activeTimers, id)) { + return; + } - // save found node - if (cmp === 0) { - found = node; + // 2. + // 3. + // TODO(@andreubotella): Error handling. + if (typeof callback === "function") { + FunctionPrototypeCall(callback, globalThis, ...args); + } else { + // TODO(@andreubotella): eval doesn't seem to have a primordial, but + // it can be redefined in the global scope. + (0, eval)(callback); } - // push the red node down - if (!isRed(node) && !isRed(node.getChild(dir))) { - if (isRed(node.getChild(!dir))) { - const sr = singleRotate(node, dir); - p.setChild(last, sr); - p = sr; - } else if (!isRed(node.getChild(!dir))) { - const sibling = p.getChild(!last); - if (sibling !== null) { - if ( - !isRed(sibling.getChild(!last)) && - !isRed(sibling.getChild(last)) - ) { - // color flip - p.red = false; - sibling.red = true; - node.red = true; - } else { - assert(gp); - const dir2 = gp.right === p; - - if (isRed(sibling.getChild(last))) { - gp.setChild(dir2, doubleRotate(p, last)); - } else if (isRed(sibling.getChild(!last))) { - gp.setChild(dir2, singleRotate(p, last)); - } - - // ensure correct coloring - const gpc = gp.getChild(dir2); - assert(gpc); - gpc.red = true; - node.red = true; - assert(gpc.left); - gpc.left.red = false; - assert(gpc.right); - gpc.right.red = false; - } - } + if (repeat) { + if (MapPrototypeHas(activeTimers, id)) { + // 4. If id does not exist in global's map of active timers, then + // abort these steps. + // NOTE: If might have been removed via the author code in handler + // calling clearTimeout() or clearInterval(). + // 5. If repeat is true, then perform the timer initialization steps + // again, given global, handler, timeout, arguments, true, and id. + initializeTimer(callback, timeout, args, true, id); } + } else { + // 6. Otherwise, remove global's map of active timers[id]. + core.tryClose(cancelRid); + MapPrototypeDelete(activeTimers, id); } - } - - // replace and remove if found - if (found !== null) { - found.data = node.data; - assert(p); - p.setChild(p.right === node, node.getChild(node.left === null)); - } - - // update root and make it black - this.#root = head.right; - if (this.#root !== null) { - this.#root.red = false; - } - - return found !== null; - } - } - - function isRed(node) { - return node !== null && node.red; - } - - function singleRotate(root, dir) { - const save = root.getChild(!dir); - assert(save); - - root.setChild(!dir, save.getChild(dir)); - save.setChild(dir, root); - - root.red = true; - save.red = false; - - return save; - } + }, - function doubleRotate(root, dir) { - root.setChild(!dir, singleRotate(root.getChild(!dir), !dir)); - return singleRotate(root, dir); - } - - const { console } = globalThis; - - // Timeout values > TIMEOUT_MAX are set to 1. - const TIMEOUT_MAX = 2 ** 31 - 1; - - let globalTimeoutDue = null; - - let nextTimerId = 1; - const idMap = new Map(); - const dueTree = new RBTree((a, b) => a.due - b.due); + // 10. Increment nesting level by one. + // 11. Set task's timer nesting level to nesting level. + nestingLevel: timerNestingLevel + 1, + }; - function clearGlobalTimeout() { - globalTimeoutDue = null; - opStopGlobalTimer(); + // 12. Let completionStep be an algorithm step which queues a global task on + // the timer task source given global to run task. + // 13. Run steps after a timeout given global, "setTimeout/setInterval", + // timeout, completionStep, and id. + runAfterTimeout( + () => ArrayPrototypePush(timerTasks, task), + timeout, + cancelRid, + ); + + return id; } - let pendingEvents = 0; - const pendingFireTimers = []; + // --------------------------------------------------------------------------- - /** Process and run a single ready timer macrotask. - * This function should be registered through Deno.core.setMacrotaskCallback. - * Returns true when all ready macrotasks have been processed, false if more - * ready ones are available. The Isolate future would rely on the return value - * to repeatedly invoke this function until depletion. Multiple invocations - * of this function one at a time ensures newly ready microtasks are processed - * before next macrotask timer callback is invoked. */ - function handleTimerMacrotask() { - if (pendingFireTimers.length > 0) { - fire(ArrayPrototypeShift(pendingFireTimers)); - return pendingFireTimers.length === 0; - } - return true; - } + /** + * @typedef ScheduledTimer + * @property {number} millis + * @property {() => void} cb + * @property {boolean} resolved + * @property {ScheduledTimer | null} prev + * @property {ScheduledTimer | null} next + */ - async function setGlobalTimeout(due, now) { - // Since JS and Rust don't use the same clock, pass the time to rust as a - // relative time value. On the Rust side we'll turn that into an absolute - // value again. - const timeout = due - now; - assert(timeout >= 0); - // Send message to the backend. - globalTimeoutDue = due; - pendingEvents++; - // FIXME(bartlomieju): this is problematic, because `clearGlobalTimeout` - // is synchronous. That means that timer is cancelled, but this promise is still pending - // until next turn of event loop. This leads to "leaking of async ops" in tests; - // because `clearTimeout/clearInterval` might be the last statement in test function - // `opSanitizer` will immediately complain that there is pending op going on, unless - // some timeout/defer is put in place to allow promise resolution. - // Ideally `clearGlobalTimeout` doesn't return until this op is resolved, but - // I'm not if that's possible. - opStartGlobalTimer(timeout); - await opWaitGlobalTimer(); - pendingEvents--; - prepareReadyTimers(); - } + /** + * A doubly linked list of timers. + * @type { { head: ScheduledTimer | null, tail: ScheduledTimer | null } } + */ + const scheduledTimers = { head: null, tail: null }; - function prepareReadyTimers() { - const now = DateNow(); - // Bail out if we're not expecting the global timer to fire. - if (globalTimeoutDue === null || pendingEvents > 0) { - return; - } - // After firing the timers that are due now, this will hold the first timer - // list that hasn't fired yet. - let nextDueNode; - while ((nextDueNode = dueTree.min()) !== null && nextDueNode.due <= now) { - dueTree.remove(nextDueNode); - // Fire all the timers in the list. - for (const timer of nextDueNode.timers) { - // With the list dropped, the timer is no longer scheduled. - timer.scheduled = false; - // Place the callback to pending timers to fire. - ArrayPrototypePush(pendingFireTimers, timer); - } - } - setOrClearGlobalTimeout(nextDueNode && nextDueNode.due, now); - } + /** + * @param {() => void} cb Will be run after the timeout, if it hasn't been + * cancelled. + * @param {number} millis + * @param {number} cancelRid + */ + function runAfterTimeout(cb, millis, cancelRid) { + /** @type {ScheduledTimer} */ + const timerObject = { + millis, + cb, + resolved: false, + prev: scheduledTimers.tail, + next: null, + }; - function setOrClearGlobalTimeout(due, now) { - if (due == null) { - clearGlobalTimeout(); + // Add timerObject to the end of the list. + if (scheduledTimers.tail === null) { + assert(scheduledTimers.head === null); + scheduledTimers.head = scheduledTimers.tail = timerObject; } else { - setGlobalTimeout(due, now); + scheduledTimers.tail.next = timerObject; + scheduledTimers.tail = timerObject; } - } - function schedule(timer, now) { - assert(!timer.scheduled); - assert(now <= timer.due); - // Find or create the list of timers that will fire at point-in-time `due`. - const maybeNewDueNode = { due: timer.due, timers: [] }; - let dueNode = dueTree.find(maybeNewDueNode); - if (dueNode === null) { - dueTree.insert(maybeNewDueNode); - dueNode = maybeNewDueNode; - } - // Append the newly scheduled timer to the list and mark it as scheduled. - ArrayPrototypePush(dueNode.timers, timer); - timer.scheduled = true; - // If the new timer is scheduled to fire before any timer that existed before, - // update the global timeout to reflect this. - if (globalTimeoutDue === null || globalTimeoutDue > timer.due) { - setOrClearGlobalTimeout(timer.due, now); - } - } + // 1. + PromisePrototypeThen( + core.opAsync("op_sleep", millis, cancelRid), + () => { + // 2. Wait until any invocations of this algorithm that had the same + // global and orderingIdentifier, that started before this one, and + // whose milliseconds is equal to or less than this one's, have + // completed. + // 4. Perform completionSteps. + + // IMPORTANT: Since the sleep ops aren't guaranteed to resolve in the + // right order, whenever one resolves, we run through the scheduled + // timers list (which is in the order in which they were scheduled), and + // we call the callback for every timer which both: + // a) has resolved, and + // b) its timeout is lower than the lowest unresolved timeout found so + // far in the list. + + timerObject.resolved = true; + + let lowestUnresolvedTimeout = NumberPOSITIVE_INFINITY; + + let currentEntry = scheduledTimers.head; + while (currentEntry !== null) { + if (currentEntry.millis < lowestUnresolvedTimeout) { + if (currentEntry.resolved) { + currentEntry.cb(); + removeFromScheduledTimers(currentEntry); + } else { + lowestUnresolvedTimeout = currentEntry.millis; + } + } - function unschedule(timer) { - // Check if our timer is pending scheduling or pending firing. - // If either is true, they are not in tree, and their idMap entry - // will be deleted soon. Remove it from queue. - let index = -1; - if ((index = ArrayPrototypeIndexOf(pendingFireTimers, timer)) >= 0) { - ArrayPrototypeSplice(pendingFireTimers, index); - return; - } - // If timer is not in the 2 pending queues and is unscheduled, - // it is not in the tree. - if (!timer.scheduled) { - return; - } - const searchKey = { due: timer.due, timers: [] }; - // Find the list of timers that will fire at point-in-time `due`. - const list = dueTree.find(searchKey).timers; - if (list.length === 1) { - // Time timer is the only one in the list. Remove the entire list. - assert(list[0] === timer); - dueTree.remove(searchKey); - // If the unscheduled timer was 'next up', find when the next timer that - // still exists is due, and update the global alarm accordingly. - if (timer.due === globalTimeoutDue) { - const nextDueNode = dueTree.min(); - setOrClearGlobalTimeout( - nextDueNode && nextDueNode.due, - DateNow(), - ); - } - } else { - // Multiple timers that are due at the same point in time. - // Remove this timer from the list. - const index = ArrayPrototypeIndexOf(list, timer); - assert(index > -1); - ArrayPrototypeSplice(list, index, 1); - } + currentEntry = currentEntry.next; + } + }, + (err) => { + if (err instanceof core.Interrupted) { + // The timer was cancelled. + removeFromScheduledTimers(timerObject); + } else { + throw err; + } + }, + ); } - function fire(timer) { - // If the timer isn't found in the ID map, that means it has been cancelled - // between the timer firing and the promise callback (this function). - if (!MapPrototypeHas(idMap, timer.id)) { - return; - } - // Reschedule the timer if it is a repeating one, otherwise drop it. - if (!timer.repeat) { - // One-shot timer: remove the timer from this id-to-timer map. - MapPrototypeDelete(idMap, timer.id); + /** @param {ScheduledTimer} timerObj */ + function removeFromScheduledTimers(timerObj) { + if (timerObj.prev !== null) { + timerObj.prev.next = timerObj.next; } else { - // Interval timer: compute when timer was supposed to fire next. - // However make sure to never schedule the next interval in the past. - const now = DateNow(); - timer.due = MathMax(now, timer.due + timer.delay); - schedule(timer, now); + assert(scheduledTimers.head === timerObj); + scheduledTimers.head = timerObj.next; } - // Call the user callback. Intermediate assignment is to avoid leaking `this` - // to it, while also keeping the stack trace neat when it shows up in there. - const callback = timer.callback; - if ("function" === typeof callback) { - callback(); + if (timerObj.next !== null) { + timerObj.next.prev = timerObj.prev; } else { - (0, eval)(callback); + assert(scheduledTimers.tail === timerObj); + scheduledTimers.tail = timerObj.prev; } } + // --------------------------------------------------------------------------- + function checkThis(thisArg) { if (thisArg !== null && thisArg !== undefined && thisArg !== globalThis) { throw new TypeError("Illegal invocation"); } } - function setTimer( - cb, - delay, - args, - repeat, - ) { - // If the callack is a function, bind `args` to the callback and bind `this` to globalThis(global). - // otherwise call `String` on it, and `eval` it on calls; do not pass variardic args to the string - let callback; - - if ("function" === typeof cb) { - callback = FunctionPrototypeBind(cb, globalThis, ...args); - } else { - callback = String(cb); - args = []; // args are ignored - } - // In the browser, the delay value must be coercible to an integer between 0 - // and INT32_MAX. Any other value will cause the timer to fire immediately. - // We emulate this behavior. - const now = DateNow(); - if (delay > TIMEOUT_MAX) { - console.warn( - `${delay} does not fit into` + - " a 32-bit signed integer." + - "\nTimeout duration was set to 1.", - ); - delay = 1; + function setTimeout(callback, timeout = 0, ...args) { + checkThis(this); + if (typeof callback !== "function") { + callback = webidl.converters.DOMString(callback); } - delay = MathMax(0, delay | 0); - - // Create a new, unscheduled timer object. - const timer = { - id: nextTimerId++, - callback, - args, - delay, - due: now + delay, - repeat, - scheduled: false, - }; - // Register the timer's existence in the id-to-timer map. - MapPrototypeSet(idMap, timer.id, timer); - // Schedule the timer in the due table. - schedule(timer, now); - return timer.id; - } + timeout = webidl.converters.long(timeout); - function setTimeout( - cb, - delay = 0, - ...args - ) { - delay >>>= 0; - checkThis(this); - return setTimer(cb, delay, args, false); + return initializeTimer(callback, timeout, args, false); } - function setInterval( - cb, - delay = 0, - ...args - ) { - delay >>>= 0; + function setInterval(callback, timeout = 0, ...args) { checkThis(this); - return setTimer(cb, delay, args, true); - } - - function clearTimer(id) { - id >>>= 0; - const timer = MapPrototypeGet(idMap, id); - if (timer === undefined) { - // Timer doesn't exist any more or never existed. This is not an error. - return; + if (typeof callback !== "function") { + callback = webidl.converters.DOMString(callback); } - // Unschedule the timer if it is currently scheduled, and forget about it. - unschedule(timer); - MapPrototypeDelete(idMap, timer.id); + timeout = webidl.converters.long(timeout); + + return initializeTimer(callback, timeout, args, true); } function clearTimeout(id = 0) { - id >>>= 0; - if (id === 0) { - return; + checkThis(this); + id = webidl.converters.long(id); + const cancelHandle = MapPrototypeGet(activeTimers, id); + if (cancelHandle !== undefined) { + core.tryClose(cancelHandle); + MapPrototypeDelete(activeTimers, id); } - clearTimer(id); } function clearInterval(id = 0) { - id >>>= 0; - if (id === 0) { - return; - } - clearTimer(id); + checkThis(this); + clearTimeout(id); } window.__bootstrap.timers = { - clearInterval, + setTimeout, setInterval, clearTimeout, - setTimeout, + clearInterval, handleTimerMacrotask, - opStopGlobalTimer, - opStartGlobalTimer, opNow, sleepSync, }; |