Data commit

Task/Singleton/PureBasic/singleton-1.basic

@@ -0,0 +1,48 @@
+Global SingletonSemaphore=CreateSemaphore(1)
+
+Interface OO_Interface    ; Interface for any value of this type
+  Get.i()
+  Set(Value.i)
+  Destroy()
+EndInterface
+
+Structure OO_Structure ; The *VTable structure
+  Get.i
+  Set.i
+  Destroy.i
+EndStructure
+
+Structure OO_Var
+  *VirtualTable.OO_Structure
+  Value.i
+EndStructure
+
+Procedure OO_Get(*Self.OO_Var)
+  ProcedureReturn *Self\Value
+EndProcedure
+
+Procedure OO_Set(*Self.OO_Var, n)
+  *Self\Value = n
+EndProcedure
+
+Procedure CreateSingleton()
+  If TrySemaphore(SingletonSemaphore)
+    *p.OO_Var = AllocateMemory(SizeOf(OO_Var))
+    If *p
+      *p\VirtualTable = ?VTable
+    EndIf
+  EndIf
+  ProcedureReturn *p
+EndProcedure
+
+Procedure OO_Destroy(*Self.OO_Var)
+  FreeMemory(*Self)
+  SignalSemaphore(SingletonSemaphore)
+EndProcedure
+
+DataSection
+  VTable:
+  Data.i @OO_Get()
+  Data.i @OO_Set()
+  Data.i @OO_Destroy()
+EndDataSection