1/* 2 * Copyright (c) 2024 Huawei Device Co., Ltd. 3 * Licensed under the Apache License, Version 2.0 (the "License"); 4 * you may not use this file except in compliance with the License. 5 * You may obtain a copy of the License at 6 * 7 * http://www.apache.org/licenses/LICENSE-2.0 8 * 9 * Unless required by applicable law or agreed to in writing, software 10 * distributed under the License is distributed on an "AS IS" BASIS, 11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 * See the License for the specific language governing permissions and 13 * limitations under the License. 14 */ 15 16import {AtomicFlag} from "std/debug/concurrency" 17 18class Event { 19 public Wait() { 20 while (this.flag.get() != true) { 21 Coroutine.Schedule(); 22 } 23 } 24 25 public Fire() { 26 this.flag.set(true); 27 } 28 29 private flag = new AtomicFlag(false); 30}; 31 32let event = new Event(); 33 34function foo() : int { 35 event.Wait(); 36 return 42; 37} 38 39function bar(p: Promise<int>) : int { 40 return await p; 41} 42 43function main() { 44 let p1 = launch foo(); 45 for (let i = 0; i < 2; ++i) { 46 let p2 = launch bar(p1); 47 } 48 // NOTE(panferovi): for more determinism we need to make sure 49 // that bar coroutines are waiting for its awakening 50 event.Fire(); 51 let result = await p1; 52 assert result == 42; 53} 54