1 files changed, 112 insertions, 0 deletions
diff --git a/src/mscorlib/src/Microsoft/Win32/SafeHandles/Win32SafeHandles.cs b/src/mscorlib/src/Microsoft/Win32/SafeHandles/Win32SafeHandles.cs
new file mode 100644
index 0000000000..58e0d7ad1d
--- /dev/null
+++ b/src/mscorlib/src/Microsoft/Win32/SafeHandles/Win32SafeHandles.cs
@@ -0,0 +1,112 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+//
+// Abstract derivations of SafeHandle designed to provide the common
+// functionality supporting Win32 handles. More specifically, they describe how
+// an invalid handle looks (for instance, some handles use -1 as an invalid
+// handle value, others use 0).
+//
+// Further derivations of these classes can specialise this even further (e.g.
+// file or registry handles).
+// 
+//
+
+namespace Microsoft.Win32.SafeHandles
+{
+    using System;
+    using System.Runtime.InteropServices;
+    using System.Runtime.CompilerServices;
+    using System.Security.Permissions;
+    using System.Runtime.ConstrainedExecution;
+
+    // Class of safe handle which uses 0 or -1 as an invalid handle.
+    [System.Security.SecurityCritical]  // auto-generated_required
+#if !FEATURE_CORECLR
+    [SecurityPermission(SecurityAction.InheritanceDemand, UnmanagedCode=true)]
+#endif
+    public abstract class SafeHandleZeroOrMinusOneIsInvalid : SafeHandle
+    {
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        protected SafeHandleZeroOrMinusOneIsInvalid(bool ownsHandle) : base(IntPtr.Zero, ownsHandle) 
+        {
+        }
+
+#if FEATURE_CORECLR
+        // A default constructor is needed to satisfy CoreCLR inheritence rules. It should not be called at runtime
+        protected SafeHandleZeroOrMinusOneIsInvalid()
+        {
+            throw new NotImplementedException();
+        }
+#endif // FEATURE_CORECLR
+
+        public override bool IsInvalid {
+            [System.Security.SecurityCritical]
+            get { return handle.IsNull() || handle == new IntPtr(-1); }
+        }
+    }
+
+    // Class of safe handle which uses only -1 as an invalid handle.
+    [System.Security.SecurityCritical]  // auto-generated_required
+#if !FEATURE_CORECLR
+    [SecurityPermission(SecurityAction.InheritanceDemand, UnmanagedCode=true)]
+#endif
+    public abstract class SafeHandleMinusOneIsInvalid : SafeHandle
+    {
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        protected SafeHandleMinusOneIsInvalid(bool ownsHandle) : base(new IntPtr(-1), ownsHandle) 
+        {
+        }
+
+#if FEATURE_CORECLR
+        // A default constructor is needed to satisfy CoreCLR inheritence rules. It should not be called at runtime
+        protected SafeHandleMinusOneIsInvalid()
+        {
+            throw new NotImplementedException();
+        }
+#endif // FEATURE_CORECLR
+
+        public override bool IsInvalid {
+            [System.Security.SecurityCritical]
+            get { return handle == new IntPtr(-1); }
+        }
+    }
+
+    // Class of critical handle which uses 0 or -1 as an invalid handle.
+    [System.Security.SecurityCritical]  // auto-generated_required
+#if !FEATURE_CORECLR
+    [SecurityPermission(SecurityAction.InheritanceDemand, UnmanagedCode=true)]
+#endif
+    public abstract class CriticalHandleZeroOrMinusOneIsInvalid : CriticalHandle
+    {
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        protected CriticalHandleZeroOrMinusOneIsInvalid() : base(IntPtr.Zero) 
+        {
+        }
+
+        public override bool IsInvalid {
+            [System.Security.SecurityCritical]
+            get { return handle.IsNull() || handle == new IntPtr(-1); }
+        }
+    }
+
+    // Class of critical handle which uses only -1 as an invalid handle.
+    [System.Security.SecurityCritical]  // auto-generated_required
+#if !FEATURE_CORECLR
+    [SecurityPermission(SecurityAction.InheritanceDemand, UnmanagedCode=true)]
+#endif
+    public abstract class CriticalHandleMinusOneIsInvalid : CriticalHandle
+    {
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        protected CriticalHandleMinusOneIsInvalid() : base(new IntPtr(-1)) 
+        {
+        }
+
+        public override bool IsInvalid {
+            [System.Security.SecurityCritical]
+            get { return handle == new IntPtr(-1); }
+        }
+    }
+
+}