thread parallel

Parallel/ThreadTask/ThreadTask.vb

@@ -0,0 +1,63 @@
+Imports Microsoft.VisualBasic.Parallel.Tasks
+
+Public Class ThreadTask(Of TOut)
+
+    Dim taskList As Queue(Of Func(Of TOut))
+    Dim threads As AsyncHandle(Of TOut)()
+
+    Sub New(task As IEnumerable(Of Func(Of TOut)))
+        Me.taskList = New Queue(Of Func(Of TOut))(task)
+    End Sub
+
+    Public Function WithDegreeOfParallelism(n_threads As Integer) As ThreadTask(Of TOut)
+        threads = New AsyncHandle(Of TOut)(n_threads) {}
+        Return Me
+    End Function
+
+    Private Function GetEmptyThread() As Integer
+        For i As Integer = 0 To threads.Length - 1
+            If threads(i) Is Nothing Then
+                Return i
+            End If
+        Next
+
+        Return -1
+    End Function
+
+    Private Function GetCompleteThread() As Integer
+        For i As Integer = 0 To threads.Length - 1
+            If (Not threads(i) Is Nothing) AndAlso threads(i).IsCompleted Then
+                Return i
+            End If
+        Next
+
+        Return -1
+    End Function
+
+    Public Iterator Function RunParallel() As IEnumerable(Of TOut)
+        Do While taskList.Count > 0
+            Dim i As Integer = GetEmptyThread()
+
+            If i > -1 Then
+                threads(i) = New AsyncHandle(Of TOut)(taskList.Dequeue).Run
+            End If
+
+            Dim j As Integer = GetCompleteThread()
+
+            If j > -1 Then
+                Yield threads(j).GetValue
+                threads(j) = Nothing
+            End If
+        Loop
+
+        Do While Not threads.All(Function(t) t Is Nothing)
+            Dim j As Integer = GetCompleteThread()
+
+            If j > -1 Then
+                Yield threads(j).GetValue
+                threads(j) = Nothing
+            End If
+        Loop
+    End Function
+
+End Class