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// 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.
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.Diagnostics;
using System.Runtime.InteropServices;
using System.Runtime.Serialization;
using System.Runtime.Versioning;
using System.Security;
using System.Threading;
namespace System.Runtime
{
internal static class Fx
{
private const string DefaultEventSource = "System.Runtime";
#if DEBUG
private const string AssertsFailFastName = "AssertsFailFast";
private const string BreakOnExceptionTypesName = "BreakOnExceptionTypes";
private const string FastDebugName = "FastDebug";
private const string StealthDebuggerName = "StealthDebugger";
private static bool s_breakOnExceptionTypesRetrieved;
private static Type[] s_breakOnExceptionTypesCache;
#endif
private static ExceptionTrace s_exceptionTrace;
private static EtwDiagnosticTrace s_diagnosticTrace;
private static bool? s_isUap;
private static ExceptionHandler s_asynchronousThreadExceptionHandler;
internal static bool IsUap
{
get
{
if (!s_isUap.HasValue)
{
s_isUap = "Microsoft Windows".Equals(RuntimeInformation.OSDescription, StringComparison.Ordinal);
}
return s_isUap.Value;
}
}
internal static ExceptionTrace Exception
{
get
{
if (s_exceptionTrace == null)
{
// don't need a lock here since a true singleton is not required
s_exceptionTrace = new ExceptionTrace(DefaultEventSource, Trace);
}
return s_exceptionTrace;
}
}
internal static EtwDiagnosticTrace Trace
{
get
{
if (s_diagnosticTrace == null)
{
s_diagnosticTrace = InitializeTracing();
}
return s_diagnosticTrace;
}
}
private static EtwDiagnosticTrace InitializeTracing()
{
return new EtwDiagnosticTrace();
}
public static ExceptionHandler AsynchronousThreadExceptionHandler
{
get
{
return Fx.s_asynchronousThreadExceptionHandler;
}
set
{
Fx.s_asynchronousThreadExceptionHandler = value;
}
}
[Conditional("DEBUG")]
public static void Assert(bool condition, string description)
{
if (!condition)
{
Assert(description);
}
}
[Conditional("DEBUG")]
public static void Assert(string description)
{
Debug.Assert(false, description);
}
public static void AssertAndThrow(bool condition, string description)
{
if (!condition)
{
AssertAndThrow(description);
}
}
[MethodImpl(MethodImplOptions.NoInlining)]
public static Exception AssertAndThrow(string description)
{
Fx.Assert(description);
TraceCore.ShipAssertExceptionMessage(Trace, description);
throw new InternalException(description);
}
public static void AssertAndThrowFatal(bool condition, string description)
{
if (!condition)
{
AssertAndThrowFatal(description);
}
}
[MethodImpl(MethodImplOptions.NoInlining)]
public static Exception AssertAndThrowFatal(string description)
{
Fx.Assert(description);
TraceCore.ShipAssertExceptionMessage(Trace, description);
throw new FatalInternalException(description);
}
public static void AssertAndFailFast(bool condition, string description)
{
if (!condition)
{
AssertAndFailFast(description);
}
}
// This never returns. The Exception return type lets you write 'throw AssertAndFailFast()' which tells the compiler/tools that
// execution stops.
[Tag.SecurityNote(Critical = "Calls into critical method Environment.FailFast",
Safe = "The side affect of the app crashing is actually intended here")]
[SecuritySafeCritical]
[MethodImpl(MethodImplOptions.NoInlining)]
public static Exception AssertAndFailFast(string description)
{
Fx.Assert(description);
string failFastMessage = InternalSR.FailFastMessage(description);
// The catch is here to force the finally to run, as finallys don't run until the stack walk gets to a catch.
// The catch makes sure that the finally will run before the stack-walk leaves the frame, but the code inside is impossible to reach.
try
{
try
{
Fx.Exception.TraceFailFast(failFastMessage);
}
finally
{
Environment.FailFast(failFastMessage);
}
}
catch
{
throw;
}
return null; // we'll never get here since we've just fail-fasted
}
public static bool IsFatal(Exception exception)
{
while (exception != null)
{
if (exception is FatalException ||
(exception is OutOfMemoryException && !(exception is InsufficientMemoryException)) ||
exception is FatalInternalException)
{
return true;
}
// These exceptions aren't themselves fatal, but since the CLR uses them to wrap other exceptions,
// we want to check to see whether they've been used to wrap a fatal exception. If so, then they
// count as fatal.
if (exception is TypeInitializationException ||
exception is TargetInvocationException)
{
exception = exception.InnerException;
}
else if (exception is AggregateException)
{
// AggregateExceptions have a collection of inner exceptions, which may themselves be other
// wrapping exceptions (including nested AggregateExceptions). Recursively walk this
// hierarchy. The (singular) InnerException is included in the collection.
ReadOnlyCollection<Exception> innerExceptions = ((AggregateException)exception).InnerExceptions;
foreach (Exception innerException in innerExceptions)
{
if (IsFatal(innerException))
{
return true;
}
}
break;
}
else
{
break;
}
}
return false;
}
// This method should be only used for debug build.
internal static bool AssertsFailFast
{
get
{
return false;
}
}
// This property should be only used for debug build.
internal static Type[] BreakOnExceptionTypes
{
get
{
#if DEBUG
if (!Fx.s_breakOnExceptionTypesRetrieved)
{
object value;
if (TryGetDebugSwitch(Fx.BreakOnExceptionTypesName, out value))
{
string[] typeNames = value as string[];
if (typeNames != null && typeNames.Length > 0)
{
List<Type> types = new List<Type>(typeNames.Length);
for (int i = 0; i < typeNames.Length; i++)
{
types.Add(Type.GetType(typeNames[i], false));
}
if (types.Count != 0)
{
Fx.s_breakOnExceptionTypesCache = types.ToArray();
}
}
}
Fx.s_breakOnExceptionTypesRetrieved = true;
}
return Fx.s_breakOnExceptionTypesCache;
#else
return null;
#endif
}
}
// This property should be only used for debug build.
internal static bool StealthDebugger
{
get
{
return false;
}
}
#if DEBUG
private static bool TryGetDebugSwitch(string name, out object value)
{
value = null;
return false;
}
#endif
public static AsyncCallback ThunkCallback(AsyncCallback callback)
{
return (new AsyncThunk(callback)).ThunkFrame;
}
public static Action<T1> ThunkCallback<T1>(Action<T1> callback)
{
return (new ActionThunk<T1>(callback)).ThunkFrame;
}
#pragma warning disable CS3002 // Return type is not CLS-compliant
#pragma warning disable CS3001 // Argument type is not CLS-compliant
[SupportedOSPlatform("windows")]
public static IOCompletionCallback ThunkCallback(IOCompletionCallback callback)
#pragma warning restore CS3001 // Argument type is not CLS-compliant
#pragma warning restore CS3002 // Return type is not CLS-compliant
{
Fx.Assert(callback != null, "Trying to create a ThunkCallback with a null callback method");
return (new IOCompletionThunk(callback)).ThunkFrame;
}
[SuppressMessage(FxCop.Category.ReliabilityBasic, FxCop.Rule.UseNewGuidHelperRule,
Justification = "These are the core methods that should be used for all other Guid(string) calls.")]
public static Guid CreateGuid(string guidString)
{
bool success = false;
Guid result = Guid.Empty;
try
{
result = new Guid(guidString);
success = true;
}
finally
{
if (!success)
{
AssertAndThrow("Creation of the Guid failed.");
}
}
return result;
}
[SuppressMessage(FxCop.Category.ReliabilityBasic, FxCop.Rule.UseNewGuidHelperRule,
Justification = "These are the core methods that should be used for all other Guid(string) calls.")]
public static bool TryCreateGuid(string guidString, out Guid result)
{
bool success = false;
result = Guid.Empty;
try
{
result = new Guid(guidString);
success = true;
}
catch (ArgumentException)
{
}
catch (FormatException)
{
}
catch (OverflowException)
{
}
return success;
}
public static byte[] AllocateByteArray(int size)
{
try
{
// Safe to catch OOM from this as long as the ONLY thing it does is a simple allocation of a primitive type (no method calls).
return new byte[size];
}
catch (OutOfMemoryException exception)
{
// Convert OOM into an exception that can be safely handled by higher layers.
throw Exception.AsError(
new InsufficientMemoryException(InternalSR.BufferAllocationFailed(size), exception));
}
}
public static char[] AllocateCharArray(int size)
{
try
{
// Safe to catch OOM from this as long as the ONLY thing it does is a simple allocation of a primitive type (no method calls).
return new char[size];
}
catch (OutOfMemoryException exception)
{
// Convert OOM into an exception that can be safely handled by higher layers.
throw Fx.Exception.AsError(
new InsufficientMemoryException(InternalSR.BufferAllocationFailed(size * sizeof(char)), exception));
}
}
[SuppressMessage(FxCop.Category.Design, FxCop.Rule.DoNotCatchGeneralExceptionTypes,
Justification = "Don't want to hide the exception which is about to crash the process.")]
[Tag.SecurityNote(Miscellaneous = "Must not call into PT code as it is called within a CER.")]
private static void TraceExceptionNoThrow(Exception exception)
{
try
{
// This call exits the CER. However, when still inside a catch, normal ThreadAbort is prevented.
// Rude ThreadAbort will still be allowed to terminate processing.
Fx.Exception.TraceUnhandledException(exception);
}
catch
{
// This empty catch is only acceptable because we are a) in a CER and b) processing an exception
// which is about to crash the process anyway.
}
}
[SuppressMessage(FxCop.Category.Design, FxCop.Rule.DoNotCatchGeneralExceptionTypes,
Justification = "Don't want to hide the exception which is about to crash the process.")]
[SuppressMessage(FxCop.Category.ReliabilityBasic, FxCop.Rule.IsFatalRule,
Justification = "Don't want to hide the exception which is about to crash the process.")]
[Tag.SecurityNote(Miscellaneous = "Must not call into PT code as it is called within a CER.")]
private static bool HandleAtThreadBase(Exception exception)
{
// This area is too sensitive to do anything but return.
if (exception == null)
{
Fx.Assert("Null exception in HandleAtThreadBase.");
return false;
}
TraceExceptionNoThrow(exception);
try
{
ExceptionHandler handler = Fx.AsynchronousThreadExceptionHandler;
return handler == null ? false : handler.HandleException(exception);
}
catch (Exception secondException)
{
// Don't let a new exception hide the original exception.
TraceExceptionNoThrow(secondException);
}
return false;
}
private static void UpdateLevel(EtwDiagnosticTrace trace)
{
if (trace == null)
{
return;
}
if (TraceCore.ActionItemCallbackInvokedIsEnabled(trace) ||
TraceCore.ActionItemScheduledIsEnabled(trace))
{
trace.SetEnd2EndActivityTracingEnabled(true);
}
}
private static void UpdateLevel()
{
UpdateLevel(Fx.Trace);
}
public abstract class ExceptionHandler
{
[Tag.SecurityNote(Miscellaneous = "Must not call into PT code as it is called within a CER.")]
public abstract bool HandleException(Exception exception);
}
// This can't derive from Thunk since T would be unsafe.
[SupportedOSPlatform("windows")]
private sealed unsafe class IOCompletionThunk
{
private readonly IOCompletionCallback _callback;
public IOCompletionThunk(IOCompletionCallback callback)
{
_callback = callback;
}
public IOCompletionCallback ThunkFrame
{
get
{
return new IOCompletionCallback(UnhandledExceptionFrame);
}
}
void UnhandledExceptionFrame(uint error, uint bytesRead, NativeOverlapped* nativeOverlapped)
{
try
{
_callback(error, bytesRead, nativeOverlapped);
}
catch (Exception exception)
{
if (!Fx.HandleAtThreadBase(exception))
{
throw;
}
}
}
}
public static class Tag
{
public enum CacheAttrition
{
None,
ElementOnTimer,
// A finalizer/WeakReference based cache, where the elements are held by WeakReferences (or hold an
// inner object by a WeakReference), and the weakly-referenced object has a finalizer which cleans the
// item from the cache.
ElementOnGC,
// A cache that provides a per-element token, delegate, interface, or other piece of context that can
// be used to remove the element (such as IDisposable).
ElementOnCallback,
FullPurgeOnTimer,
FullPurgeOnEachAccess,
PartialPurgeOnTimer,
PartialPurgeOnEachAccess,
}
public enum ThrottleAction
{
Reject,
Pause,
}
public enum ThrottleMetric
{
Count,
Rate,
Other,
}
public enum Location
{
InProcess,
OutOfProcess,
LocalSystem,
LocalOrRemoteSystem, // as in a file that might live on a share
RemoteSystem,
}
public enum SynchronizationKind
{
LockStatement,
MonitorWait,
MonitorExplicit,
InterlockedNoSpin,
InterlockedWithSpin,
// Same as LockStatement if the field type is object.
FromFieldType,
}
[Flags]
public enum BlocksUsing
{
MonitorEnter,
MonitorWait,
ManualResetEvent,
AutoResetEvent,
AsyncResult,
IAsyncResult,
PInvoke,
InputQueue,
ThreadNeutralSemaphore,
PrivatePrimitive,
OtherInternalPrimitive,
OtherFrameworkPrimitive,
OtherInterop,
Other,
NonBlocking, // For use by non-blocking SynchronizationPrimitives such as IOThreadScheduler
}
public static class Strings
{
internal const string ExternallyManaged = "externally managed";
internal const string AppDomain = "AppDomain";
internal const string DeclaringInstance = "instance of declaring class";
internal const string Unbounded = "unbounded";
internal const string Infinite = "infinite";
}
[AttributeUsage(AttributeTargets.Method | AttributeTargets.Constructor | AttributeTargets.Property | AttributeTargets.Class,
AllowMultiple = true, Inherited = false)]
[Conditional("DEBUG")]
public sealed class FriendAccessAllowedAttribute : Attribute
{
public FriendAccessAllowedAttribute(string assemblyName) :
base()
{
AssemblyName = assemblyName;
}
public string AssemblyName { get; set; }
}
public static class Throws
{
[AttributeUsage(AttributeTargets.Method | AttributeTargets.Constructor,
AllowMultiple = true, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class TimeoutAttribute : ThrowsAttribute
{
public TimeoutAttribute() :
this("The operation timed out.")
{
}
public TimeoutAttribute(string diagnosis) :
base(typeof(TimeoutException), diagnosis)
{
}
}
}
[AttributeUsage(AttributeTargets.Field)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class CacheAttribute : Attribute
{
private readonly CacheAttrition _cacheAttrition;
public CacheAttribute(Type elementType, CacheAttrition cacheAttrition)
{
Scope = Strings.DeclaringInstance;
SizeLimit = Strings.Unbounded;
Timeout = Strings.Infinite;
ElementType = elementType ?? throw Fx.Exception.ArgumentNull("elementType");
_cacheAttrition = cacheAttrition;
}
public Type ElementType { get; }
public CacheAttrition CacheAttrition
{
get
{
return _cacheAttrition;
}
}
public string Scope { get; set; }
public string SizeLimit { get; set; }
public string Timeout { get; set; }
}
[AttributeUsage(AttributeTargets.Field)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class QueueAttribute : Attribute
{
public QueueAttribute(Type elementType)
{
Scope = Strings.DeclaringInstance;
SizeLimit = Strings.Unbounded;
ElementType = elementType ?? throw Fx.Exception.ArgumentNull("elementType");
}
public Type ElementType { get; }
public string Scope { get; set; }
public string SizeLimit { get; set; }
public bool StaleElementsRemovedImmediately { get; set; }
public bool EnqueueThrowsIfFull { get; set; }
}
[AttributeUsage(AttributeTargets.Field)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class ThrottleAttribute : Attribute
{
private readonly string _limit;
public ThrottleAttribute(ThrottleAction throttleAction, ThrottleMetric throttleMetric, string limit)
{
Scope = Strings.AppDomain;
if (string.IsNullOrEmpty(limit))
{
throw Fx.Exception.ArgumentNullOrEmpty("limit");
}
ThrottleAction = throttleAction;
ThrottleMetric = throttleMetric;
_limit = limit;
}
public ThrottleAction ThrottleAction { get; }
public ThrottleMetric ThrottleMetric { get; }
public string Limit
{
get
{
return _limit;
}
}
public string Scope
{
get; set;
}
}
[AttributeUsage(AttributeTargets.Field | AttributeTargets.Method | AttributeTargets.Constructor,
AllowMultiple = true, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class ExternalResourceAttribute : Attribute
{
private readonly string _description;
public ExternalResourceAttribute(Location location, string description)
{
Location = location;
_description = description;
}
public Location Location { get; }
public string Description
{
get
{
return _description;
}
}
}
// Set on a class when that class uses lock (this) - acts as though it were on a field
// private object this;
[AttributeUsage(AttributeTargets.Field | AttributeTargets.Class, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class SynchronizationObjectAttribute : Attribute
{
public SynchronizationObjectAttribute()
{
Blocking = true;
Scope = Strings.DeclaringInstance;
Kind = SynchronizationKind.FromFieldType;
}
public bool Blocking { get; set; }
public string Scope { get; set; }
public SynchronizationKind Kind { get; set; }
}
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct, Inherited = true)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class SynchronizationPrimitiveAttribute : Attribute
{
public SynchronizationPrimitiveAttribute(BlocksUsing blocksUsing)
{
BlocksUsing = blocksUsing;
}
public BlocksUsing BlocksUsing { get; }
public bool SupportsAsync { get; set; }
public bool Spins { get; set; }
public string ReleaseMethod { get; set; }
}
[AttributeUsage(AttributeTargets.Method | AttributeTargets.Constructor, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class BlockingAttribute : Attribute
{
public BlockingAttribute()
{
}
public string CancelMethod { get; set; }
public Type CancelDeclaringType { get; set; }
public string Conditional { get; set; }
}
// Sometime a method will call a conditionally-blocking method in such a way that it is guaranteed
// not to block (i.e. the condition can be Asserted false). Such a method can be marked as
// GuaranteeNonBlocking as an assertion that the method doesn't block despite calling a blocking method.
//
// Methods that don't call blocking methods and aren't marked as Blocking are assumed not to block, so
// they do not require this attribute.
[AttributeUsage(AttributeTargets.Method | AttributeTargets.Constructor, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class GuaranteeNonBlockingAttribute : Attribute
{
public GuaranteeNonBlockingAttribute()
{
}
}
[AttributeUsage(AttributeTargets.Method | AttributeTargets.Constructor, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class NonThrowingAttribute : Attribute
{
public NonThrowingAttribute()
{
}
}
[SuppressMessage(FxCop.Category.Performance, "CA1813:AvoidUnsealedAttributes",
Justification = "This is intended to be an attribute hierarchy. It does not affect product perf.")]
[AttributeUsage(AttributeTargets.Method | AttributeTargets.Constructor,
AllowMultiple = true, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public class ThrowsAttribute : Attribute
{
private readonly string _diagnosis;
public ThrowsAttribute(Type exceptionType, string diagnosis)
{
if (string.IsNullOrEmpty(diagnosis))
{
throw Fx.Exception.ArgumentNullOrEmpty("diagnosis");
}
ExceptionType = exceptionType ?? throw Fx.Exception.ArgumentNull("exceptionType");
_diagnosis = diagnosis;
}
public Type ExceptionType { get; }
public string Diagnosis
{
get
{
return _diagnosis;
}
}
}
[AttributeUsage(AttributeTargets.Method | AttributeTargets.Constructor, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class InheritThrowsAttribute : Attribute
{
public InheritThrowsAttribute()
{
}
public Type FromDeclaringType { get; set; }
public string From { get; set; }
}
[AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class KnownXamlExternalAttribute : Attribute
{
public KnownXamlExternalAttribute()
{
}
}
[AttributeUsage(AttributeTargets.Assembly | AttributeTargets.Class | AttributeTargets.Struct, AllowMultiple = false, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class XamlVisibleAttribute : Attribute
{
public XamlVisibleAttribute()
: this(true)
{
}
public XamlVisibleAttribute(bool visible)
{
Visible = visible;
}
public bool Visible
{
get;
private set;
}
}
[AttributeUsage(AttributeTargets.Assembly | AttributeTargets.Module | AttributeTargets.Class |
AttributeTargets.Struct | AttributeTargets.Enum | AttributeTargets.Constructor | AttributeTargets.Method |
AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Event | AttributeTargets.Interface |
AttributeTargets.Delegate, AllowMultiple = false, Inherited = false)]
[Conditional("CODE_ANALYSIS_CDF")]
public sealed class SecurityNoteAttribute : Attribute
{
public SecurityNoteAttribute()
{
}
public string Critical
{
get;
set;
}
public string Safe
{
get;
set;
}
public string Miscellaneous
{
get;
set;
}
}
}
internal abstract class Thunk<T> where T : class
{
[Tag.SecurityNote(Critical = "Make these safe to use in SecurityCritical contexts.")]
[SecurityCritical]
private T _callback;
[Tag.SecurityNote(Critical = "Accesses critical field.", Safe = "Data provided by caller.")]
[SecuritySafeCritical]
protected Thunk(T callback)
{
_callback = callback;
}
internal T Callback
{
[Tag.SecurityNote(Critical = "Accesses critical field.", Safe = "Data is not privileged.")]
[SecuritySafeCritical]
get
{
return _callback;
}
}
}
internal sealed class ActionThunk<T1> : Thunk<Action<T1>>
{
public ActionThunk(Action<T1> callback) : base(callback)
{
}
public Action<T1> ThunkFrame
{
get
{
return new Action<T1>(UnhandledExceptionFrame);
}
}
[Tag.SecurityNote(Critical = "Calls PrepareConstrainedRegions which has a LinkDemand",
Safe = "Guaranteed not to call into PT user code from the finally.")]
[SecuritySafeCritical]
private void UnhandledExceptionFrame(T1 result)
{
try
{
Callback(result);
}
catch (Exception exception)
{
if (!Fx.HandleAtThreadBase(exception))
{
throw;
}
}
}
}
internal sealed class AsyncThunk : Thunk<AsyncCallback>
{
public AsyncThunk(AsyncCallback callback) : base(callback)
{
}
public AsyncCallback ThunkFrame
{
get
{
return new AsyncCallback(UnhandledExceptionFrame);
}
}
[Tag.SecurityNote(Critical = "Calls PrepareConstrainedRegions which has a LinkDemand",
Safe = "Guaranteed not to call into PT user code from the finally.")]
[SecuritySafeCritical]
private void UnhandledExceptionFrame(IAsyncResult result)
{
try
{
Callback(result);
}
catch (Exception exception)
{
if (!Fx.HandleAtThreadBase(exception))
{
throw;
}
}
}
}
[Serializable]
internal class InternalException : SystemException
{
public InternalException(string description) : base(InternalSR.ShipAssertExceptionMessage(description)) { }
#pragma warning disable SYSLIB0051
protected InternalException(SerializationInfo info, StreamingContext context) : base(info, context) { }
#pragma warning restore SYSLIB0051
}
[Serializable]
internal class FatalInternalException : InternalException
{
public FatalInternalException(string description) : base(description) { }
#pragma warning disable SYSLIB0051
protected FatalInternalException(SerializationInfo info, StreamingContext context) : base(info, context) { }
#pragma warning restore SYSLIB0051
}
}
}
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