Imported Upstream version 4.6.0.125

Former-commit-id: a2155e9bd80020e49e72e86c44da02a8ac0e57a4

mcs/class/referencesource/System.Data/System/Data/Common/SafeNativeMethods.cs

@@ -0,0 +1,154 @@
+//------------------------------------------------------------------------------
+// <copyright file="SafeNativeMethods.cs" company="Microsoft">
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+// </copyright>
+// <owner current="true" primary="true">[....]</owner>
+// <owner current="true" primary="false">[....]</owner>
+// <owner current="true" primary="false">[....]</owner>
+//------------------------------------------------------------------------------
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+using System.Security;
+using System.Security.Permissions;
+using System.Text;
+using System.Threading;
+using System.Runtime.ConstrainedExecution;
+using System.Runtime.Versioning;
+
+namespace System.Data.Common {
+
+    [SuppressUnmanagedCodeSecurityAttribute()]
+    internal static class SafeNativeMethods {
+    
+        [DllImport(ExternDll.Ole32, SetLastError=false)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern IntPtr CoTaskMemAlloc(IntPtr cb);
+
+        [DllImport(ExternDll.Ole32, SetLastError=false)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern void CoTaskMemFree(IntPtr handle);
+
+        [DllImport(ExternDll.Kernel32, CharSet=CharSet.Unicode, PreserveSig=true)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern int GetUserDefaultLCID();
+
+        [DllImport(ExternDll.Kernel32, PreserveSig=true)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern void ZeroMemory(IntPtr dest, IntPtr length);
+
+        // <WARNING>
+        // Using the int versions of the Increment() and Decrement() methods is correct.
+        // Please check \fx\src\Data\System\Data\Odbc\OdbcHandle.cs for the memory layout.
+        // </WARNING>
+
+        // <NDPWHIDBEY 18133>
+        // The following casting operations require these three methods to be unsafe.  This is
+        // a workaround for this issue to meet the M1 exit criteria.  We need to revisit this in M2.
+
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        static internal unsafe IntPtr InterlockedExchangePointer(
+                IntPtr lpAddress,
+                IntPtr lpValue)
+        {
+            IntPtr  previousPtr;
+            IntPtr  actualPtr = *(IntPtr *)lpAddress.ToPointer();
+
+            do {
+                previousPtr = actualPtr;
+                actualPtr   = Interlocked.CompareExchange(ref *(IntPtr *)lpAddress.ToPointer(), lpValue, previousPtr);
+            }
+            while (actualPtr != previousPtr);
+
+            return actualPtr;
+        }
+
+        // http://msdn.microsoft.com/library/default.asp?url=/library/en-us/sysinfo/base/getcomputernameex.asp
+        [DllImport(ExternDll.Kernel32, CharSet = CharSet.Unicode, EntryPoint="GetComputerNameExW", SetLastError=true)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern int GetComputerNameEx(int nameType, StringBuilder nameBuffer, ref int bufferSize);
+
+        [DllImport(ExternDll.Kernel32, CharSet=System.Runtime.InteropServices.CharSet.Auto)]
+        [ResourceExposure(ResourceScope.Process)]
+        static internal extern int GetCurrentProcessId();
+
+        [DllImport(ExternDll.Kernel32, CharSet=CharSet.Auto, BestFitMapping=false, ThrowOnUnmappableChar=true)]
+//        [DllImport(ExternDll.Kernel32, CharSet=CharSet.Auto)]
+        [ResourceExposure(ResourceScope.Process)]
+        static internal extern IntPtr GetModuleHandle([MarshalAs(UnmanagedType.LPTStr), In] string moduleName/*lpctstr*/);
+
+        [DllImport(ExternDll.Kernel32, CharSet = CharSet.Ansi, BestFitMapping = false, ThrowOnUnmappableChar = true, SetLastError = true)]
+//        [DllImport(ExternDll.Kernel32, CharSet=CharSet.Ansi)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern IntPtr GetProcAddress(IntPtr HModule, [MarshalAs(UnmanagedType.LPStr), In] string funcName/*lpcstr*/);
+
+        [DllImport(ExternDll.Kernel32, SetLastError=true)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern IntPtr LocalAlloc(int flags, IntPtr countOfBytes);
+
+        [DllImport(ExternDll.Kernel32, SetLastError=true)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern IntPtr LocalFree(IntPtr handle);
+
+        [DllImport(ExternDll.Oleaut32, CharSet=CharSet.Unicode)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]            
+        [ResourceExposure(ResourceScope.None)]
+        internal static extern IntPtr SysAllocStringLen(String src, int len);  // BSTR
+
+        [DllImport(ExternDll.Oleaut32)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+        [ResourceExposure(ResourceScope.None)]
+        internal static extern void SysFreeString(IntPtr bstr);
+
+        // only using this to clear existing error info with null
+        [DllImport(ExternDll.Oleaut32, CharSet=CharSet.Unicode, PreserveSig=false)]
+        // TLS values are preserved between threads, need to check that we use this API to clear the error state only.
+        [ResourceExposure(ResourceScope.Process)]
+        static private extern void SetErrorInfo(Int32 dwReserved, IntPtr pIErrorInfo);
+
+        [DllImport(ExternDll.Kernel32, SetLastError=true)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        [ResourceExposure(ResourceScope.Machine)]
+        static internal extern int ReleaseSemaphore(IntPtr handle, int releaseCount, IntPtr previousCount);
+
+        [DllImport(ExternDll.Kernel32, SetLastError=true)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern int WaitForMultipleObjectsEx(uint nCount, IntPtr lpHandles, bool bWaitAll, uint dwMilliseconds, bool bAlertable);
+
+        [DllImport(ExternDll.Kernel32/*, SetLastError=true*/)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.MayFail)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern int WaitForSingleObjectEx(IntPtr lpHandles, uint dwMilliseconds, bool bAlertable);
+
+        [DllImport(ExternDll.Ole32, PreserveSig=false)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern void PropVariantClear(IntPtr pObject);
+
+        [DllImport(ExternDll.Oleaut32, PreserveSig=false)]
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+        [ResourceExposure(ResourceScope.None)]
+        static internal extern void VariantClear(IntPtr pObject);
+
+        sealed internal class Wrapper {
+
+            private Wrapper() { }
+
+            // SxS: clearing error information is considered safe
+            [ResourceExposure(ResourceScope.None)]
+            [ResourceConsumption(ResourceScope.Process, ResourceScope.Process)]
+            static internal void ClearErrorInfo() { // MDAC 68199
+                SafeNativeMethods.SetErrorInfo(0, ADP.PtrZero);
+            }
+        }
+
+
+    }
+}