WIP

src/Lock.ts

@@ -2,11 +2,11 @@ import type { MutexInterface } from 'async-mutex';
 import type { ResourceAcquire } from '@matrixai/resources';
 import { Mutex, withTimeout } from 'async-mutex';
 import { withF, withG } from '@matrixai/resources';
+import { sleep } from './utils';
 import { ErrorAsyncLocksTimeout } from './errors';
 
 class Lock {
   protected _lock: Mutex = new Mutex();
-  protected release: MutexInterface.Releaser;
   protected _count: number = 0;
 
   public lock(timeout?: number): ResourceAcquire<Lock> {
@@ -16,16 +16,19 @@ class Lock {
       if (timeout != null) {
         lock = withTimeout(this._lock, timeout, new ErrorAsyncLocksTimeout());
       }
+      let release: MutexInterface.Releaser;
       try {
-        this.release = await lock.acquire();
+        release = await lock.acquire();
       } catch (e) {
         --this._count;
         throw e;
       }
       return [
         async () => {
           --this._count;
-          this.release();
+          release();
+          // Allow semaphore to settle https://github.com/DirtyHairy/async-mutex/issues/54
+          await sleep(0);
         },
         this,
       ];

src/RWLockReader.ts

@@ -2,6 +2,7 @@ import type { MutexInterface } from 'async-mutex';
 import type { ResourceAcquire } from '@matrixai/resources';
 import { Mutex, withTimeout } from 'async-mutex';
 import { withF, withG } from '@matrixai/resources';
+import { sleep } from './utils';
 import { ErrorAsyncLocksTimeout } from './errors';
 
 /**
@@ -23,24 +24,21 @@ class RWLockReader {
           lock = withTimeout(this.lock, timeout, new ErrorAsyncLocksTimeout());
         }
         try {
-          console.log('ATTEMPT READ');
           this.release = await lock.acquire();
-          console.log('ACQUIRED READ');
-
         } catch (e) {
-          console.log('READ LOCK TIMEOUT', e.name);
           --this._readerCount;
           throw e;
         }
       }
       return [
         async () => {
-          console.log('RELEASE READ LOCK');
           const readerCount = --this._readerCount;
           // The last reader unlocks
           if (readerCount === 0) {
             this.release();
           }
+          // Allow semaphore to settle https://github.com/DirtyHairy/async-mutex/issues/54
+          await sleep(0);
         },
         this,
       ];
@@ -56,20 +54,17 @@ class RWLockReader {
       }
       let release: MutexInterface.Releaser;
       try {
-        console.log('ATTEMPT WRITE');
         release = await lock.acquire();
-        console.log('ACQUIRED WRITE');
-
       } catch (e) {
-        console.log('WRITE LOCK TIMEOUT', e.name);
         --this._writerCount;
         throw e;
       }
       return [
         async () => {
-          console.log('RELEASE WRITE LOCK');
           release();
           --this._writerCount;
+          // Allow semaphore to settle https://github.com/DirtyHairy/async-mutex/issues/54
+          await sleep(0);
         },
         this,
       ];

src/RWLockWriter.ts

@@ -3,6 +3,7 @@ import type { ResourceAcquire } from '@matrixai/resources';
 import { performance } from 'perf_hooks';
 import { Mutex, withTimeout } from 'async-mutex';
 import { withF, withG } from '@matrixai/resources';
+import { sleep } from './utils';
 import { ErrorAsyncLocksTimeout } from './errors';
 
 /**
@@ -67,6 +68,8 @@ class RWLockWriter {
           // The last reader unlocks
           if (readerCount === 0) {
             this.readersRelease();
+            // Allow semaphore to settle https://github.com/DirtyHairy/async-mutex/issues/54
+            await sleep(0);
           }
         },
         this,
@@ -99,13 +102,17 @@ class RWLockWriter {
       } catch (e) {
         writersRelease();
         --this._writerCount;
+        // Allow semaphore to settle https://github.com/DirtyHairy/async-mutex/issues/54
+        await sleep(0);
         throw e;
       }
       return [
         async () => {
           this.readersRelease();
           writersRelease();
           --this._writerCount;
+          // Allow semaphore to settle https://github.com/DirtyHairy/async-mutex/issues/54
+          await sleep(0);
         },
         this,
       ];

src/index.ts

@@ -1,3 +1,6 @@
 export { default as Lock } from './Lock';
 export { default as RWLockReader } from './RWLockReader';
 export { default as RWLockWriter } from './RWLockWriter';
+export * as errors from './errors';
+export * as utils from './utils';
+export * as types from './types';

tests/Lock.test.ts

@@ -1,7 +1,7 @@
 import { withF, withG } from '@matrixai/resources';
 import Lock from '@/Lock';
+import * as utils from '@/utils';
 import * as errors from '@/errors';
-import * as testUtils from './utils';
 
 describe(Lock.name, () => {
   test('withF', async () => {
@@ -97,7 +97,7 @@ describe(Lock.name, () => {
     let value;
     const p1 = withF([lock.lock()], async () => {
       value = 'p1';
-      await testUtils.sleep(100);
+      await utils.sleep(100);
     });
     const p2 = lock.waitForUnlock().then(() => {
       value = 'p2';
@@ -124,12 +124,12 @@ describe(Lock.name, () => {
     await Promise.all([
       lock.withF(async () => {
         const value_ = value + 1;
-        await testUtils.sleep(100);
+        await utils.sleep(100);
         value = value_;
       }),
       lock.withF(async () => {
         const value_ = value + 1;
-        await testUtils.sleep(100);
+        await utils.sleep(100);
         value = value_;
       }),
     ]);
@@ -139,7 +139,7 @@ describe(Lock.name, () => {
       (async () => {
         const g = lock.withG(async function* (): AsyncGenerator {
           const value_ = value + 1;
-          await testUtils.sleep(100);
+          await utils.sleep(100);
           value = value_;
           return 'last';
         });
@@ -149,7 +149,7 @@ describe(Lock.name, () => {
       (async () => {
         const g = lock.withG(async function* (): AsyncGenerator {
           const value_ = value + 1;
-          await testUtils.sleep(100);
+          await utils.sleep(100);
           value = value_;
           return 'last';
         });