292 lines
11 KiB
JavaScript
292 lines
11 KiB
JavaScript
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const E_TIMEOUT = new Error('timeout while waiting for mutex to become available');
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const E_ALREADY_LOCKED = new Error('mutex already locked');
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const E_CANCELED = new Error('request for lock canceled');
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var __awaiter$2 = (undefined && undefined.__awaiter) || function (thisArg, _arguments, P, generator) {
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function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
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return new (P || (P = Promise))(function (resolve, reject) {
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function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
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function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
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function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
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step((generator = generator.apply(thisArg, _arguments || [])).next());
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});
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};
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class Semaphore {
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constructor(_value, _cancelError = E_CANCELED) {
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this._value = _value;
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this._cancelError = _cancelError;
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this._queue = [];
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this._weightedWaiters = [];
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}
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acquire(weight = 1, priority = 0) {
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if (weight <= 0)
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throw new Error(`invalid weight ${weight}: must be positive`);
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return new Promise((resolve, reject) => {
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const task = { resolve, reject, weight, priority };
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const i = findIndexFromEnd(this._queue, (other) => priority <= other.priority);
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if (i === -1 && weight <= this._value) {
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// Needs immediate dispatch, skip the queue
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this._dispatchItem(task);
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}
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else {
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this._queue.splice(i + 1, 0, task);
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}
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});
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}
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runExclusive(callback_1) {
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return __awaiter$2(this, arguments, void 0, function* (callback, weight = 1, priority = 0) {
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const [value, release] = yield this.acquire(weight, priority);
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try {
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return yield callback(value);
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}
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finally {
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release();
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}
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});
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}
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waitForUnlock(weight = 1, priority = 0) {
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if (weight <= 0)
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throw new Error(`invalid weight ${weight}: must be positive`);
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if (this._couldLockImmediately(weight, priority)) {
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return Promise.resolve();
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}
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else {
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return new Promise((resolve) => {
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if (!this._weightedWaiters[weight - 1])
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this._weightedWaiters[weight - 1] = [];
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insertSorted(this._weightedWaiters[weight - 1], { resolve, priority });
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});
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}
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}
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isLocked() {
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return this._value <= 0;
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}
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getValue() {
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return this._value;
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}
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setValue(value) {
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this._value = value;
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this._dispatchQueue();
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}
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release(weight = 1) {
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if (weight <= 0)
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throw new Error(`invalid weight ${weight}: must be positive`);
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this._value += weight;
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this._dispatchQueue();
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}
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cancel() {
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this._queue.forEach((entry) => entry.reject(this._cancelError));
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this._queue = [];
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}
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_dispatchQueue() {
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this._drainUnlockWaiters();
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while (this._queue.length > 0 && this._queue[0].weight <= this._value) {
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this._dispatchItem(this._queue.shift());
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this._drainUnlockWaiters();
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}
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}
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_dispatchItem(item) {
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const previousValue = this._value;
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this._value -= item.weight;
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item.resolve([previousValue, this._newReleaser(item.weight)]);
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}
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_newReleaser(weight) {
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let called = false;
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return () => {
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if (called)
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return;
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called = true;
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this.release(weight);
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};
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}
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_drainUnlockWaiters() {
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if (this._queue.length === 0) {
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for (let weight = this._value; weight > 0; weight--) {
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const waiters = this._weightedWaiters[weight - 1];
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if (!waiters)
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continue;
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waiters.forEach((waiter) => waiter.resolve());
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this._weightedWaiters[weight - 1] = [];
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}
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}
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else {
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const queuedPriority = this._queue[0].priority;
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for (let weight = this._value; weight > 0; weight--) {
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const waiters = this._weightedWaiters[weight - 1];
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if (!waiters)
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continue;
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const i = waiters.findIndex((waiter) => waiter.priority <= queuedPriority);
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(i === -1 ? waiters : waiters.splice(0, i))
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.forEach((waiter => waiter.resolve()));
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}
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}
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}
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_couldLockImmediately(weight, priority) {
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return (this._queue.length === 0 || this._queue[0].priority < priority) &&
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weight <= this._value;
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}
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}
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function insertSorted(a, v) {
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const i = findIndexFromEnd(a, (other) => v.priority <= other.priority);
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a.splice(i + 1, 0, v);
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}
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function findIndexFromEnd(a, predicate) {
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for (let i = a.length - 1; i >= 0; i--) {
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if (predicate(a[i])) {
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return i;
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}
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}
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return -1;
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}
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var __awaiter$1 = (undefined && undefined.__awaiter) || function (thisArg, _arguments, P, generator) {
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function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
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return new (P || (P = Promise))(function (resolve, reject) {
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function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
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function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
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function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
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step((generator = generator.apply(thisArg, _arguments || [])).next());
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});
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};
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class Mutex {
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constructor(cancelError) {
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this._semaphore = new Semaphore(1, cancelError);
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}
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acquire() {
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return __awaiter$1(this, arguments, void 0, function* (priority = 0) {
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const [, releaser] = yield this._semaphore.acquire(1, priority);
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return releaser;
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});
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}
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runExclusive(callback, priority = 0) {
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return this._semaphore.runExclusive(() => callback(), 1, priority);
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}
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isLocked() {
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return this._semaphore.isLocked();
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}
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waitForUnlock(priority = 0) {
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return this._semaphore.waitForUnlock(1, priority);
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}
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release() {
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if (this._semaphore.isLocked())
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this._semaphore.release();
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}
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cancel() {
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return this._semaphore.cancel();
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}
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}
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var __awaiter = (undefined && undefined.__awaiter) || function (thisArg, _arguments, P, generator) {
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function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
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return new (P || (P = Promise))(function (resolve, reject) {
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function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
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function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
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function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
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step((generator = generator.apply(thisArg, _arguments || [])).next());
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});
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};
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function withTimeout(sync, timeout, timeoutError = E_TIMEOUT) {
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return {
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acquire: (weightOrPriority, priority) => {
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let weight;
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if (isSemaphore(sync)) {
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weight = weightOrPriority;
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}
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else {
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weight = undefined;
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priority = weightOrPriority;
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}
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if (weight !== undefined && weight <= 0) {
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throw new Error(`invalid weight ${weight}: must be positive`);
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}
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return new Promise((resolve, reject) => __awaiter(this, void 0, void 0, function* () {
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let isTimeout = false;
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const handle = setTimeout(() => {
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isTimeout = true;
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reject(timeoutError);
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}, timeout);
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try {
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const ticket = yield (isSemaphore(sync)
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? sync.acquire(weight, priority)
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: sync.acquire(priority));
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if (isTimeout) {
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const release = Array.isArray(ticket) ? ticket[1] : ticket;
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release();
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}
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else {
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clearTimeout(handle);
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resolve(ticket);
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}
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}
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catch (e) {
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if (!isTimeout) {
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clearTimeout(handle);
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reject(e);
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}
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}
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}));
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},
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runExclusive(callback, weight, priority) {
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return __awaiter(this, void 0, void 0, function* () {
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let release = () => undefined;
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try {
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const ticket = yield this.acquire(weight, priority);
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if (Array.isArray(ticket)) {
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release = ticket[1];
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return yield callback(ticket[0]);
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}
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else {
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release = ticket;
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return yield callback();
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}
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}
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finally {
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release();
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}
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});
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},
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release(weight) {
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sync.release(weight);
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},
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cancel() {
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return sync.cancel();
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},
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waitForUnlock: (weightOrPriority, priority) => {
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let weight;
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if (isSemaphore(sync)) {
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weight = weightOrPriority;
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}
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else {
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weight = undefined;
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priority = weightOrPriority;
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}
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if (weight !== undefined && weight <= 0) {
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throw new Error(`invalid weight ${weight}: must be positive`);
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}
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return new Promise((resolve, reject) => {
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const handle = setTimeout(() => reject(timeoutError), timeout);
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(isSemaphore(sync)
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? sync.waitForUnlock(weight, priority)
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: sync.waitForUnlock(priority)).then(() => {
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clearTimeout(handle);
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resolve();
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});
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});
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},
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isLocked: () => sync.isLocked(),
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getValue: () => sync.getValue(),
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setValue: (value) => sync.setValue(value),
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};
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}
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function isSemaphore(sync) {
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return sync.getValue !== undefined;
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}
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// eslint-disable-next-lisne @typescript-eslint/explicit-module-boundary-types
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function tryAcquire(sync, alreadyAcquiredError = E_ALREADY_LOCKED) {
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// eslint-disable-next-line @typescript-eslint/no-explicit-any
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return withTimeout(sync, 0, alreadyAcquiredError);
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}
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export { E_ALREADY_LOCKED, E_CANCELED, E_TIMEOUT, Mutex, Semaphore, tryAcquire, withTimeout };
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