Simplify distributed lock creation

sillsdev · Sep 5, 2023 · 464421d · 464421d
1 parent d0792ff
commit 464421d
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Showing 9 changed files with 197 additions and 176 deletions.
diff --git a/src/SIL.Machine.AspNetCore/Services/DistributedReaderWriterLock.cs b/src/SIL.Machine.AspNetCore/Services/DistributedReaderWriterLock.cs
@@ -7,23 +7,19 @@ public class DistributedReaderWriterLock : IDistributedReaderWriterLock
     private readonly IIdGenerator _idGenerator;
     private readonly string _id;
 
-    private bool _lockChecked;
-
     public DistributedReaderWriterLock(string hostId, IRepository<RWLock> locks, IIdGenerator idGenerator, string id)
     {
         _hostId = hostId;
         _locks = locks;
         _idGenerator = idGenerator;
         _id = id;
-        _lockChecked = false;
     }
 
     public async Task<IAsyncDisposable> ReaderLockAsync(
         TimeSpan? lifetime = default,
         CancellationToken cancellationToken = default
     )
     {
-        await createLockIfNotExist();
         string lockId = _idGenerator.GenerateId();
         if (!await TryAcquireReaderLock(lockId, lifetime, cancellationToken))
         {
@@ -53,7 +49,6 @@ public async Task<IAsyncDisposable> WriterLockAsync(
         CancellationToken cancellationToken = default
     )
     {
-        await createLockIfNotExist();
         string lockId = _idGenerator.GenerateId();
         if (!await TryAcquireWriterLock(lockId, lifetime, cancellationToken))
         {
@@ -101,23 +96,6 @@ await _locks.UpdateAsync(
         return new WriterLockReleaser(this, lockId);
     }
 
-    private async Task createLockIfNotExist()
-    {
-        if (_lockChecked == false)
-        {
-            try
-            {
-                await _locks.InsertAsync(new RWLock { Id = _id }, CancellationToken.None);
-            }
-            catch (DuplicateKeyException)
-            {
-                // the lock is already made - no new one needs to be made
-                // This is done instead of checking if it exists first to prevent race conditions.
-            }
-            _lockChecked = true;
-        }
-    }
-
     private async Task<bool> TryAcquireWriterLock(
         string lockId,
         TimeSpan? lifetime,

diff --git a/src/SIL.Machine.AspNetCore/Services/DistributedReaderWriterLockFactory.cs b/src/SIL.Machine.AspNetCore/Services/DistributedReaderWriterLockFactory.cs
@@ -24,8 +24,20 @@ public async Task InitAsync(CancellationToken cancellationToken = default)
         await ReleaseAllReaderLocksAsync(cancellationToken);
     }
 
-    public IDistributedReaderWriterLock Create(string id)
+    public async Task<IDistributedReaderWriterLock> CreateAsync(
+        string id,
+        CancellationToken cancellationToken = default
+    )
     {
+        try
+        {
+            await _locks.InsertAsync(new RWLock { Id = id }, cancellationToken);
+        }
+        catch (DuplicateKeyException)
+        {
+            // the lock is already made - no new one needs to be made
+            // This is done instead of checking if it exists first to prevent race conditions.
+        }
         return new DistributedReaderWriterLock(_serviceOptions.ServiceId, _locks, _idGenerator, id);
     }
 

diff --git a/src/SIL.Machine.AspNetCore/Services/IDistributedReaderWriterLockFactory.cs b/src/SIL.Machine.AspNetCore/Services/IDistributedReaderWriterLockFactory.cs
@@ -3,6 +3,6 @@
 public interface IDistributedReaderWriterLockFactory
 {
     Task InitAsync(CancellationToken cancellationToken = default);
-    IDistributedReaderWriterLock Create(string id);
+    Task<IDistributedReaderWriterLock> CreateAsync(string id, CancellationToken cancellationToken = default);
     Task<bool> DeleteAsync(string id, CancellationToken cancellationToken = default);
 }
diff --git a/src/SIL.Machine.AspNetCore/Services/SmtTransferEngineBuildJob.cs b/src/SIL.Machine.AspNetCore/Services/SmtTransferEngineBuildJob.cs
@@ -42,7 +42,7 @@ public async Task RunAsync(
         CancellationToken cancellationToken
     )
     {
-        IDistributedReaderWriterLock rwLock = _lockFactory.Create(engineId);
+        IDistributedReaderWriterLock rwLock = await _lockFactory.CreateAsync(engineId, cancellationToken);
 
         var tokenizer = new LatinWordTokenizer();
         var detokenizer = new LatinWordDetokenizer();

diff --git a/src/SIL.Machine.AspNetCore/Services/SmtTransferEngineService.cs b/src/SIL.Machine.AspNetCore/Services/SmtTransferEngineService.cs
@@ -33,7 +33,7 @@ public override async Task CreateAsync(
         await base.CreateAsync(engineId, engineName, sourceLanguage, targetLanguage, cancellationToken);
 
         SmtTransferEngineState state = _stateService.Get(engineId);
-        IDistributedReaderWriterLock @lock = LockFactory.Create(engineId);
+        IDistributedReaderWriterLock @lock = await LockFactory.CreateAsync(engineId, CancellationToken.None);
         await using (await @lock.WriterLockAsync(cancellationToken: CancellationToken.None))
         {
             state.InitNew();
@@ -45,7 +45,7 @@ public override async Task DeleteAsync(string engineId, CancellationToken cancel
         await base.DeleteAsync(engineId, cancellationToken);
         if (_stateService.TryRemove(engineId, out SmtTransferEngineState? state))
         {
-            IDistributedReaderWriterLock @lock = LockFactory.Create(engineId);
+            IDistributedReaderWriterLock @lock = await LockFactory.CreateAsync(engineId, CancellationToken.None);
             await using (await @lock.WriterLockAsync(cancellationToken: CancellationToken.None))
             {
                 // ensure that there is no build running before unloading
@@ -67,7 +67,7 @@ public override async Task<IReadOnlyList<TranslationResult>> TranslateAsync(
     )
     {
         SmtTransferEngineState state = _stateService.Get(engineId);
-        IDistributedReaderWriterLock @lock = LockFactory.Create(engineId);
+        IDistributedReaderWriterLock @lock = await LockFactory.CreateAsync(engineId, cancellationToken);
         await using (await @lock.ReaderLockAsync(cancellationToken: cancellationToken))
         {
             TranslationEngine engine = await GetEngineAsync(engineId, cancellationToken);
@@ -85,7 +85,7 @@ public override async Task<WordGraph> GetWordGraphAsync(
     )
     {
         SmtTransferEngineState state = _stateService.Get(engineId);
-        IDistributedReaderWriterLock @lock = LockFactory.Create(engineId);
+        IDistributedReaderWriterLock @lock = await LockFactory.CreateAsync(engineId, cancellationToken);
         await using (await @lock.ReaderLockAsync(cancellationToken: cancellationToken))
         {
             TranslationEngine engine = await GetEngineAsync(engineId, cancellationToken);
@@ -105,7 +105,7 @@ public override async Task TrainSegmentPairAsync(
     )
     {
         SmtTransferEngineState state = _stateService.Get(engineId);
-        IDistributedReaderWriterLock @lock = LockFactory.Create(engineId);
+        IDistributedReaderWriterLock @lock = await LockFactory.CreateAsync(engineId, cancellationToken);
         await using (await @lock.WriterLockAsync(cancellationToken: cancellationToken))
         {
             TranslationEngine engine = await GetEngineAsync(engineId, cancellationToken);
@@ -142,7 +142,7 @@ public override async Task StartBuildAsync(
     )
     {
         SmtTransferEngineState state = _stateService.Get(engineId);
-        IDistributedReaderWriterLock @lock = LockFactory.Create(engineId);
+        IDistributedReaderWriterLock @lock = await LockFactory.CreateAsync(engineId, cancellationToken);
         await using (await @lock.WriterLockAsync(cancellationToken: cancellationToken))
         {
             await StartBuildInternalAsync(engineId, buildId, corpora, cancellationToken);
@@ -153,7 +153,7 @@ public override async Task StartBuildAsync(
     public override async Task CancelBuildAsync(string engineId, CancellationToken cancellationToken = default)
     {
         SmtTransferEngineState state = _stateService.Get(engineId);
-        IDistributedReaderWriterLock @lock = LockFactory.Create(engineId);
+        IDistributedReaderWriterLock @lock = await LockFactory.CreateAsync(engineId, cancellationToken);
         await using (await @lock.WriterLockAsync(cancellationToken: cancellationToken))
         {
             await CancelBuildInternalAsync(engineId, cancellationToken);

diff --git a/src/SIL.Machine.AspNetCore/Services/SmtTransferEngineStateService.cs b/src/SIL.Machine.AspNetCore/Services/SmtTransferEngineStateService.cs
@@ -38,7 +38,7 @@ TimeSpan inactiveTimeout
     {
         foreach (SmtTransferEngineState state in _engineStates.Values)
         {
-            IDistributedReaderWriterLock @lock = lockFactory.Create(state.EngineId);
+            IDistributedReaderWriterLock @lock = await lockFactory.CreateAsync(state.EngineId);
             await using (await @lock.WriterLockAsync())
             {
                 TranslationEngine? engine = await engines.GetAsync(e => e.EngineId == state.EngineId);

diff --git a/src/SIL.Machine.AspNetCore/Services/TranslationEngineServiceBase.cs b/src/SIL.Machine.AspNetCore/Services/TranslationEngineServiceBase.cs
@@ -60,7 +60,7 @@ public virtual async Task StartBuildAsync(
         CancellationToken cancellationToken = default
     )
     {
-        IDistributedReaderWriterLock @lock = LockFactory.Create(engineId);
+        IDistributedReaderWriterLock @lock = await LockFactory.CreateAsync(engineId, cancellationToken);
         await using (await @lock.WriterLockAsync(cancellationToken: cancellationToken))
         {
             await StartBuildInternalAsync(engineId, buildId, corpora, cancellationToken);
@@ -69,7 +69,7 @@ public virtual async Task StartBuildAsync(
 
     public virtual async Task CancelBuildAsync(string engineId, CancellationToken cancellationToken = default)
     {
-        IDistributedReaderWriterLock @lock = LockFactory.Create(engineId);
+        IDistributedReaderWriterLock @lock = await LockFactory.CreateAsync(engineId, cancellationToken);
         await using (await @lock.WriterLockAsync(cancellationToken: cancellationToken))
         {
             await CancelBuildInternalAsync(engineId, cancellationToken);