Imported Upstream version 4.0.0~alpha1

Former-commit-id: 806294f5ded97629b74c85c09952f2a74fe182d9

external/referencesource/mscorlib/system/sharedstatics.cs

@@ -0,0 +1,177 @@
+// ==++==
+// 
+//   Copyright (c) Microsoft Corporation.  All rights reserved.
+// 
+// ==--==
+/*=============================================================================
+**
+** Class: SharedStatics
+**
+**
+** Purpose: Container for statics that are shared across AppDomains.
+**
+**
+=============================================================================*/
+
+namespace System {
+
+    using System.Threading;
+    using System.Runtime.Remoting;
+    using System.Security;
+    using System.Security.Util;
+    using System.Runtime.CompilerServices;
+    using System.Runtime.ConstrainedExecution;
+    using System.Diagnostics.Contracts;
+#if FEATURE_CAS_POLICY || FEATURE_LEGACYNETCFCRYPTO
+    using StringMaker = System.Security.Util.Tokenizer.StringMaker;
+#endif // FEATURE_CAS_POLICY
+
+    internal sealed class SharedStatics
+    {
+        // this is declared static but is actually forced to be the same object 
+        // for each AppDomain at AppDomain create time.
+        private static SharedStatics _sharedStatics;
+        
+        // Note: Do not add any code in this ctor because it is not called 
+        // when we set up _sharedStatics via AppDomain::SetupSharedStatics
+        private SharedStatics()
+        {
+            BCLDebug.Assert(false, "SharedStatics..ctor() is never called.");
+        }
+
+        private volatile String _Remoting_Identity_IDGuid;
+        public static String Remoting_Identity_IDGuid 
+        { 
+            [System.Security.SecuritySafeCritical]  // auto-generated
+            get 
+            {
+                if (_sharedStatics._Remoting_Identity_IDGuid == null)
+                {
+                    bool tookLock = false;
+                    RuntimeHelpers.PrepareConstrainedRegions();
+                    try {
+                        Monitor.Enter(_sharedStatics, ref tookLock);
+
+                        if (_sharedStatics._Remoting_Identity_IDGuid == null)
+                        {
+                            _sharedStatics._Remoting_Identity_IDGuid = Guid.NewGuid().ToString().Replace('-', '_');
+                        }
+                    }
+                    finally {
+                        if (tookLock)
+                            Monitor.Exit(_sharedStatics);
+                    }
+                }
+
+                Contract.Assert(_sharedStatics._Remoting_Identity_IDGuid != null,
+                                "_sharedStatics._Remoting_Identity_IDGuid != null");
+                return _sharedStatics._Remoting_Identity_IDGuid;
+            } 
+        }
+
+#if FEATURE_CAS_POLICY || FEATURE_LEGACYNETCFCRYPTO
+        private StringMaker _maker;
+        [System.Security.SecuritySafeCritical]  // auto-generated
+        static public StringMaker GetSharedStringMaker()
+        {
+            StringMaker maker = null;
+            
+            bool tookLock = false;
+            RuntimeHelpers.PrepareConstrainedRegions();
+            try {
+                Monitor.Enter(_sharedStatics, ref tookLock);
+
+                if (_sharedStatics._maker != null)
+                {
+                    maker = _sharedStatics._maker;
+                    _sharedStatics._maker = null;
+                }
+            }
+            finally {
+                if (tookLock)
+                    Monitor.Exit(_sharedStatics);
+            }
+            
+            if (maker == null)
+            {
+                maker = new StringMaker();
+            }
+            
+            return maker;
+        }
+
+        [System.Security.SecuritySafeCritical]  // auto-generated
+        static public void ReleaseSharedStringMaker(ref StringMaker maker)
+        {
+            // save this stringmaker so someone else can use it
+            bool tookLock = false;
+            RuntimeHelpers.PrepareConstrainedRegions();
+            try
+            {
+                Monitor.Enter(_sharedStatics, ref tookLock);
+
+                _sharedStatics._maker = maker;
+                maker = null;
+            }
+            finally {
+                if (tookLock)
+                    Monitor.Exit(_sharedStatics);
+            }
+        }
+#endif // FEATURE_CAS_POLICY
+
+        // Note this may not need to be process-wide.
+        private int _Remoting_Identity_IDSeqNum;
+        internal static int Remoting_Identity_GetNextSeqNum()
+        {
+            return Interlocked.Increment(ref _sharedStatics._Remoting_Identity_IDSeqNum);
+        }
+
+
+        // This is the total amount of memory currently "reserved" via
+        // all MemoryFailPoints allocated within the process.
+        // Stored as a long because we need to use Interlocked.Add.
+        private long _memFailPointReservedMemory;
+
+        [ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+        internal static long AddMemoryFailPointReservation(long size)
+        {
+            // Size can legitimately be negative - see Dispose.
+            return Interlocked.Add(ref _sharedStatics._memFailPointReservedMemory, (long) size);
+        }
+
+        internal static ulong MemoryFailPointReservedMemory {
+            get { 
+                Contract.Assert(Volatile.Read(ref _sharedStatics._memFailPointReservedMemory) >= 0, "Process-wide MemoryFailPoint reserved memory was negative!");
+                return (ulong) Volatile.Read(ref _sharedStatics._memFailPointReservedMemory);
+            }
+        }
+
+#if FEATURE_CORECLR
+        // Silverlight2 implementation restriction (all hosts must specify the same PLATFORM_ASSEMBLIES list.)
+        internal static bool ConflictsWithPriorPlatformList(String platformListString)
+        {
+            if (platformListString == null)
+            {
+                platformListString = "";   // null is valid but collides with _platformListString sentinel so convert to semantically equivalent "".
+            }
+            String prior = Interlocked.CompareExchange<String>(ref _sharedStatics._platformListString, platformListString, null);
+
+            if (prior == null)
+            {
+                return false;
+            }
+            if (prior == platformListString)
+            {
+                return false;
+            }
+
+            return true;
+        }
+
+        private String _platformListString;
+
+#endif //FEATURE_CORECLR
+
+    }
+}