69 lines
2.1 KiB
JavaScript
69 lines
2.1 KiB
JavaScript
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"use strict";
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/* --------------------------------------------------------------------------------------------
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* Copyright (c) Microsoft Corporation. All rights reserved.
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* Licensed under the MIT License. See License.txt in the project root for license information.
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* ------------------------------------------------------------------------------------------ */
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Object.defineProperty(exports, "__esModule", { value: true });
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exports.Semaphore = void 0;
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const ral_1 = require("./ral");
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class Semaphore {
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constructor(capacity = 1) {
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if (capacity <= 0) {
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throw new Error('Capacity must be greater than 0');
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}
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this._capacity = capacity;
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this._active = 0;
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this._waiting = [];
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}
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lock(thunk) {
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return new Promise((resolve, reject) => {
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this._waiting.push({ thunk, resolve, reject });
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this.runNext();
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});
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}
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get active() {
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return this._active;
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}
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runNext() {
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if (this._waiting.length === 0 || this._active === this._capacity) {
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return;
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}
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(0, ral_1.default)().timer.setImmediate(() => this.doRunNext());
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}
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doRunNext() {
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if (this._waiting.length === 0 || this._active === this._capacity) {
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return;
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}
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const next = this._waiting.shift();
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this._active++;
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if (this._active > this._capacity) {
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throw new Error(`To many thunks active`);
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}
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try {
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const result = next.thunk();
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if (result instanceof Promise) {
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result.then((value) => {
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this._active--;
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next.resolve(value);
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this.runNext();
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}, (err) => {
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this._active--;
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next.reject(err);
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this.runNext();
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});
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}
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else {
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this._active--;
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next.resolve(result);
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this.runNext();
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}
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}
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catch (err) {
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this._active--;
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next.reject(err);
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this.runNext();
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}
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}
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}
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exports.Semaphore = Semaphore;
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