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| 1 | +import { expect, test } from "bun:test"; |
| 2 | +import { RWLock } from "./rw-lock"; |
| 3 | + |
| 4 | +// Note: The actual lock logic is handled by the @rocicorp/lock library. |
| 5 | +// These tests verify that our wrapper correctly implements Symbol.asyncDispose |
| 6 | +// and that basic read/write lock semantics work as expected. |
| 7 | +test("RWLock: write lock blocks readers", async () => { |
| 8 | + const lock = new RWLock(); |
| 9 | + const events: string[] = []; |
| 10 | + |
| 11 | + let writerAcquired: () => void = () => { |
| 12 | + throw new Error("writerAcquired not set"); |
| 13 | + }; |
| 14 | + let releaseWriter: () => void = () => { |
| 15 | + throw new Error("releaseWriter not set"); |
| 16 | + }; |
| 17 | + const writerHasAcquired = new Promise<void>((resolve) => { |
| 18 | + writerAcquired = resolve; |
| 19 | + }); |
| 20 | + const writerCanRelease = new Promise<void>((resolve) => { |
| 21 | + releaseWriter = resolve; |
| 22 | + }); |
| 23 | + |
| 24 | + // Acquire write lock |
| 25 | + const writerPromise = (async () => { |
| 26 | + using writeLock = await lock.write(); |
| 27 | + events.push("writer-acquired"); |
| 28 | + writerAcquired(); |
| 29 | + await writerCanRelease; |
| 30 | + // give a chance for a bug to happen. it shouldn't! |
| 31 | + await new Promise((resolve) => setTimeout(resolve, 10)); |
| 32 | + events.push("writer-releasing"); |
| 33 | + })(); |
| 34 | + |
| 35 | + // Wait for writer to actually acquire the lock |
| 36 | + await writerHasAcquired; |
| 37 | + |
| 38 | + // Try to acquire read lock (should wait) |
| 39 | + const readerPromise = (async () => { |
| 40 | + events.push("reader-waiting"); |
| 41 | + using readLock = await lock.read(); |
| 42 | + events.push("reader-acquired"); |
| 43 | + })(); |
| 44 | + |
| 45 | + releaseWriter(); |
| 46 | + |
| 47 | + await Promise.all([writerPromise, readerPromise]); |
| 48 | + |
| 49 | + // Reader should wait for writer to release |
| 50 | + expect(events).toEqual([ |
| 51 | + "writer-acquired", |
| 52 | + "reader-waiting", |
| 53 | + "writer-releasing", |
| 54 | + "reader-acquired", |
| 55 | + ]); |
| 56 | +}); |
| 57 | + |
| 58 | +test("RWLock: readers block write lock", async () => { |
| 59 | + const lock = new RWLock(); |
| 60 | + const events: string[] = []; |
| 61 | + |
| 62 | + let readerAcquired: () => void = () => { |
| 63 | + throw new Error("readerAcquired not set"); |
| 64 | + }; |
| 65 | + let releaseReader: () => void = () => { |
| 66 | + throw new Error("releaseReader not set"); |
| 67 | + }; |
| 68 | + const readerHasAcquired = new Promise<void>((resolve) => { |
| 69 | + readerAcquired = resolve; |
| 70 | + }); |
| 71 | + const readerCanRelease = new Promise<void>((resolve) => { |
| 72 | + releaseReader = resolve; |
| 73 | + }); |
| 74 | + |
| 75 | + // Acquire read lock |
| 76 | + const readerPromise = (async () => { |
| 77 | + using readLock = await lock.read(); |
| 78 | + events.push("reader-acquired"); |
| 79 | + readerAcquired(); |
| 80 | + await readerCanRelease; |
| 81 | + // give a chance for a bug to happen. it shouldn't! |
| 82 | + await new Promise((resolve) => setTimeout(resolve, 10)); |
| 83 | + events.push("reader-releasing"); |
| 84 | + })(); |
| 85 | + |
| 86 | + // Wait for reader to actually acquire the lock |
| 87 | + await readerHasAcquired; |
| 88 | + |
| 89 | + // Try to acquire write lock (should wait) |
| 90 | + const writerPromise = (async () => { |
| 91 | + events.push("writer-waiting"); |
| 92 | + using writeLock = await lock.write(); |
| 93 | + events.push("writer-acquired"); |
| 94 | + })(); |
| 95 | + |
| 96 | + releaseReader(); |
| 97 | + |
| 98 | + await Promise.all([readerPromise, writerPromise]); |
| 99 | + |
| 100 | + // Writer should wait for reader to release |
| 101 | + expect(events).toEqual([ |
| 102 | + "reader-acquired", |
| 103 | + "writer-waiting", |
| 104 | + "reader-releasing", |
| 105 | + "writer-acquired", |
| 106 | + ]); |
| 107 | +}); |
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