Improved SemaphoreSlim handling

ricado-group · Feb 24, 2022 · b887146 · b887146
1 parent 2907c29
commit b887146
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Showing 3 changed files with 28 additions and 22 deletions.
diff --git a/RICADO.Unitronics/Channels/EthernetChannel.cs b/RICADO.Unitronics/Channels/EthernetChannel.cs
@@ -78,13 +78,13 @@ public void Dispose()
 
         public async Task InitializeAsync(int timeout, CancellationToken cancellationToken)
         {
-            try
+            if (!_semaphore.Wait(0))
             {
-                if (!_semaphore.Wait(0))
-                {
-                    await _semaphore.WaitAsync(cancellationToken);
-                }
+                await _semaphore.WaitAsync(cancellationToken);
+            }
 
+            try
+            {
                 destroyClient();
 
                 await initializeClient(timeout, cancellationToken);
@@ -107,13 +107,13 @@ public async Task<ProcessMessageResult> ProcessMessageAsync(ReadOnlyMemory<byte>
 
             while (attempts <= retries)
             {
-                try
+                if (!_semaphore.Wait(0))
                 {
-                    if (!_semaphore.Wait(0))
-                    {
-                        await _semaphore.WaitAsync(cancellationToken);
-                    }
+                    await _semaphore.WaitAsync(cancellationToken);
+                }
 
+                try
+                {
                     if (attempts > 0)
                     {
                         await destroyAndInitializeClient(timeout, cancellationToken);

diff --git a/RICADO.Unitronics/Channels/SerialOverLANChannel.cs b/RICADO.Unitronics/Channels/SerialOverLANChannel.cs
@@ -116,10 +116,13 @@ public async Task InitializeAsync(int timeout, CancellationToken cancellationTok
                 }
             }
 
-            try
+            if (!_initializeSemaphore.Wait(0))
             {
                 await _initializeSemaphore.WaitAsync(cancellationToken);
+            }
 
+            try
+            {
                 if (IsInitialized)
                 {
                     return;
@@ -165,10 +168,13 @@ public async Task<ProcessMessageResult> ProcessMessageAsync(ReadOnlyMemory<byte>
 
             while (attempts <= retries)
             {
-                try
+                if (!_requestSemaphore.Wait(0))
                 {
                     await _requestSemaphore.WaitAsync(cancellationToken);
+                }
 
+                try
+                {
                     if (attempts > 0)
                     {
                         await destroyAndInitializeClient(unitId, timeout, cancellationToken);

diff --git a/RICADO.Unitronics/Channels/SerialOverLANFactory.cs b/RICADO.Unitronics/Channels/SerialOverLANFactory.cs
@@ -70,13 +70,13 @@ public async Task<SerialOverLANChannel> GetOrCreate(Guid uniqueId, string remote
 
             SerialOverLANChannel channel;
 
-            try
+            if (!_semaphore.Wait(0))
             {
-                if (!_semaphore.Wait(0))
-                {
-                    await _semaphore.WaitAsync(cancellationToken);
-                }
+                await _semaphore.WaitAsync(cancellationToken);
+            }
 
+            try
+            {
                 channel = _channels.GetOrAdd(channelKey, (key) =>
                 {
                     return new SerialOverLANChannel(remoteHost, port);
@@ -118,13 +118,13 @@ public async Task<bool> TryRemove(Guid uniqueId, string remoteHost, int port, Ca
 
             string channelKey = getChannelKey(remoteHost, port);
 
-            try
+            if (!_semaphore.Wait(0))
             {
-                if (!_semaphore.Wait(0))
-                {
-                    await _semaphore.WaitAsync(cancellationToken);
-                }
+                await _semaphore.WaitAsync(cancellationToken);
+            }
 
+            try
+            {
                 if (_channels.TryGetValue(channelKey, out SerialOverLANChannel existingChannel))
                 {
                     existingChannel.UnregisterPLC(uniqueId);