ConcurrentQueue<T> F# snippet (dotnet#8856)

Author: albert-du

snippets/fsharp/System.Collections.Concurrent/ConcurrentQueueT/Overview/concqueue.fs

@@ -0,0 +1,43 @@
+//<snippet1>
+open System
+open System.Collections.Concurrent
+open System.Threading
+open System.Threading.Tasks
+
+// Demonstrates:
+// ConcurrentQueue<T>.Enqueue()
+// ConcurrentQueue<T>.TryPeek()
+// ConcurrentQueue<T>.TryDequeue()
+
+// Construct a ConcurrentQueue.
+let cq = ConcurrentQueue<int>()
+
+// Populate the queue.
+for i = 0 to 9999 do
+    cq.Enqueue i
+
+// Peek at the first element.
+let mutable result = 0
+
+if cq.TryPeek &result |> not then
+    printfn "CQ: TryPeek failed when it should have succeeded"
+elif result <> 0 then
+    printfn $"CQ: Expected TryPeek result of 0, got {result}"
+
+let mutable outerSum = 0
+// An action to consume the ConcurrentQueue.
+let action =
+    Action(fun () ->
+        let mutable localSum = 0
+        let mutable localValue = 0
+
+        while cq.TryDequeue &localValue do
+            localSum <- localSum + localValue
+
+        Interlocked.Add(&outerSum, localSum) |> ignore)
+
+// Start 4 concurrent consuming actions.
+Parallel.Invoke(action, action, action, action)
+
+printfn $"outerSum = {outerSum}, should be 49995000"
+//</snippet1>

snippets/fsharp/System.Collections.Concurrent/ConcurrentQueueT/Overview/fs.fsproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="concqueue.fs" />
+  </ItemGroup>
+</Project>

xml/System.Collections.Concurrent/ConcurrentQueue`1.xml

@@ -103,6 +103,7 @@
  The following example shows how to use a <xref:System.Collections.Concurrent.ConcurrentQueue%601> to enqueue and dequeue items:  
   
  :::code language="csharp" source="~/snippets/csharp/System.Collections.Concurrent/ConcurrentQueueT/Overview/concqueue.cs" id="Snippet1":::
+ :::code language="fsharp" source="~/snippets/fsharp/System.Collections.Concurrent/ConcurrentQueueT/Overview/concqueue.fs" id="Snippet1":::
  :::code language="vb" source="~/snippets/visualbasic/VS_Snippets_CLR_System/system.collections.concurrent.concurrentqueue/vb/concqueue.vb" id="Snippet1":::  
   
  ]]></format>