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-rw-r--r--src/mscorlib/src/System/Threading/ExecutionContext.cs380
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diff --git a/src/mscorlib/src/System/Threading/ExecutionContext.cs b/src/mscorlib/src/System/Threading/ExecutionContext.cs
deleted file mode 100644
index 47a55a3bb9..0000000000
--- a/src/mscorlib/src/System/Threading/ExecutionContext.cs
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@@ -1,380 +0,0 @@
-// 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.
-/*============================================================
-**
-**
-**
-** Purpose: Capture execution context for a thread
-**
-**
-===========================================================*/
-namespace System.Threading
-{
- using System;
- using System.Security;
- using System.Runtime.Remoting;
- using System.Collections;
- using System.Collections.Generic;
- using System.Reflection;
- using System.Runtime.ExceptionServices;
- using System.Runtime.Serialization;
- using System.Runtime.InteropServices;
- using System.Runtime.CompilerServices;
- using System.Runtime.ConstrainedExecution;
- using System.Diagnostics;
- using System.Diagnostics.Contracts;
- using System.Diagnostics.CodeAnalysis;
-
- public delegate void ContextCallback(Object state);
-
- internal struct ExecutionContextSwitcher
- {
- internal ExecutionContext m_ec;
- internal SynchronizationContext m_sc;
-
- internal void Undo(Thread currentThread)
- {
- Debug.Assert(currentThread == Thread.CurrentThread);
-
- // The common case is that these have not changed, so avoid the cost of a write if not needed.
- if (currentThread.SynchronizationContext != m_sc)
- {
- currentThread.SynchronizationContext = m_sc;
- }
-
- if (currentThread.ExecutionContext != m_ec)
- {
- ExecutionContext.Restore(currentThread, m_ec);
- }
- }
- }
-
- [Serializable]
- public sealed class ExecutionContext : IDisposable, ISerializable
- {
- internal static readonly ExecutionContext Default = new ExecutionContext();
-
- private readonly IAsyncLocalValueMap m_localValues;
- private readonly IAsyncLocal[] m_localChangeNotifications;
- private readonly bool m_isFlowSuppressed;
-
- private ExecutionContext()
- {
- m_localValues = AsyncLocalValueMap.Empty;
- m_localChangeNotifications = Array.Empty<IAsyncLocal>();
- }
-
- private ExecutionContext(
- IAsyncLocalValueMap localValues,
- IAsyncLocal[] localChangeNotifications,
- bool isFlowSuppressed)
- {
- m_localValues = localValues;
- m_localChangeNotifications = localChangeNotifications;
- m_isFlowSuppressed = isFlowSuppressed;
- }
-
- public void GetObjectData(SerializationInfo info, StreamingContext context)
- {
- if (info == null)
- {
- throw new ArgumentNullException(nameof(info));
- }
- Contract.EndContractBlock();
- }
-
- private ExecutionContext(SerializationInfo info, StreamingContext context)
- {
- }
-
- public static ExecutionContext Capture()
- {
- ExecutionContext executionContext = Thread.CurrentThread.ExecutionContext;
- return
- executionContext == null ? Default :
- executionContext.m_isFlowSuppressed ? null :
- executionContext;
- }
-
- private ExecutionContext ShallowClone(bool isFlowSuppressed)
- {
- Debug.Assert(isFlowSuppressed != m_isFlowSuppressed);
-
- if (!isFlowSuppressed &&
- m_localValues == Default.m_localValues &&
- m_localChangeNotifications == Default.m_localChangeNotifications)
- {
- return null; // implies the default context
- }
- return new ExecutionContext(m_localValues, m_localChangeNotifications, isFlowSuppressed);
- }
-
- public static AsyncFlowControl SuppressFlow()
- {
- Thread currentThread = Thread.CurrentThread;
- ExecutionContext executionContext = currentThread.ExecutionContext ?? Default;
- if (executionContext.m_isFlowSuppressed)
- {
- throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CannotSupressFlowMultipleTimes"));
- }
- Contract.EndContractBlock();
-
- executionContext = executionContext.ShallowClone(isFlowSuppressed: true);
- var asyncFlowControl = new AsyncFlowControl();
- currentThread.ExecutionContext = executionContext;
- asyncFlowControl.Initialize(currentThread);
- return asyncFlowControl;
- }
-
- public static void RestoreFlow()
- {
- Thread currentThread = Thread.CurrentThread;
- ExecutionContext executionContext = currentThread.ExecutionContext;
- if (executionContext == null || !executionContext.m_isFlowSuppressed)
- {
- throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CannotRestoreUnsupressedFlow"));
- }
- Contract.EndContractBlock();
-
- currentThread.ExecutionContext = executionContext.ShallowClone(isFlowSuppressed: false);
- }
-
- public static bool IsFlowSuppressed()
- {
- ExecutionContext executionContext = Thread.CurrentThread.ExecutionContext;
- return executionContext != null && executionContext.m_isFlowSuppressed;
- }
-
- [HandleProcessCorruptedStateExceptions]
- public static void Run(ExecutionContext executionContext, ContextCallback callback, Object state)
- {
- if (executionContext == null)
- throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_NullContext"));
-
- Thread currentThread = Thread.CurrentThread;
- ExecutionContextSwitcher ecsw = default(ExecutionContextSwitcher);
- try
- {
- EstablishCopyOnWriteScope(currentThread, ref ecsw);
- ExecutionContext.Restore(currentThread, executionContext);
- callback(state);
- }
- catch
- {
- // Note: we have a "catch" rather than a "finally" because we want
- // to stop the first pass of EH here. That way we can restore the previous
- // context before any of our callers' EH filters run. That means we need to
- // end the scope separately in the non-exceptional case below.
- ecsw.Undo(currentThread);
- throw;
- }
- ecsw.Undo(currentThread);
- }
-
- internal static void Restore(Thread currentThread, ExecutionContext executionContext)
- {
- Debug.Assert(currentThread == Thread.CurrentThread);
-
- ExecutionContext previous = currentThread.ExecutionContext ?? Default;
- currentThread.ExecutionContext = executionContext;
-
- // New EC could be null if that's what ECS.Undo saved off.
- // For the purposes of dealing with context change, treat this as the default EC
- executionContext = executionContext ?? Default;
-
- if (previous != executionContext)
- {
- OnContextChanged(previous, executionContext);
- }
- }
-
- static internal void EstablishCopyOnWriteScope(Thread currentThread, ref ExecutionContextSwitcher ecsw)
- {
- Debug.Assert(currentThread == Thread.CurrentThread);
-
- ecsw.m_ec = currentThread.ExecutionContext;
- ecsw.m_sc = currentThread.SynchronizationContext;
- }
-
- [HandleProcessCorruptedStateExceptions]
- private static void OnContextChanged(ExecutionContext previous, ExecutionContext current)
- {
- Debug.Assert(previous != null);
- Debug.Assert(current != null);
- Debug.Assert(previous != current);
-
- foreach (IAsyncLocal local in previous.m_localChangeNotifications)
- {
- object previousValue;
- object currentValue;
- previous.m_localValues.TryGetValue(local, out previousValue);
- current.m_localValues.TryGetValue(local, out currentValue);
-
- if (previousValue != currentValue)
- local.OnValueChanged(previousValue, currentValue, true);
- }
-
- if (current.m_localChangeNotifications != previous.m_localChangeNotifications)
- {
- try
- {
- foreach (IAsyncLocal local in current.m_localChangeNotifications)
- {
- // If the local has a value in the previous context, we already fired the event for that local
- // in the code above.
- object previousValue;
- if (!previous.m_localValues.TryGetValue(local, out previousValue))
- {
- object currentValue;
- current.m_localValues.TryGetValue(local, out currentValue);
-
- if (previousValue != currentValue)
- local.OnValueChanged(previousValue, currentValue, true);
- }
- }
- }
- catch (Exception ex)
- {
- Environment.FailFast(
- Environment.GetResourceString("ExecutionContext_ExceptionInAsyncLocalNotification"),
- ex);
- }
- }
- }
-
- internal static object GetLocalValue(IAsyncLocal local)
- {
- ExecutionContext current = Thread.CurrentThread.ExecutionContext;
- if (current == null)
- return null;
-
- object value;
- current.m_localValues.TryGetValue(local, out value);
- return value;
- }
-
- internal static void SetLocalValue(IAsyncLocal local, object newValue, bool needChangeNotifications)
- {
- ExecutionContext current = Thread.CurrentThread.ExecutionContext ?? ExecutionContext.Default;
-
- object previousValue;
- bool hadPreviousValue = current.m_localValues.TryGetValue(local, out previousValue);
-
- if (previousValue == newValue)
- return;
-
- IAsyncLocalValueMap newValues = current.m_localValues.Set(local, newValue);
-
- //
- // Either copy the change notification array, or create a new one, depending on whether we need to add a new item.
- //
- IAsyncLocal[] newChangeNotifications = current.m_localChangeNotifications;
- if (needChangeNotifications)
- {
- if (hadPreviousValue)
- {
- Debug.Assert(Array.IndexOf(newChangeNotifications, local) >= 0);
- }
- else
- {
- int newNotificationIndex = newChangeNotifications.Length;
- Array.Resize(ref newChangeNotifications, newNotificationIndex + 1);
- newChangeNotifications[newNotificationIndex] = local;
- }
- }
-
- Thread.CurrentThread.ExecutionContext =
- new ExecutionContext(newValues, newChangeNotifications, current.m_isFlowSuppressed);
-
- if (needChangeNotifications)
- {
- local.OnValueChanged(previousValue, newValue, false);
- }
- }
-
- public ExecutionContext CreateCopy()
- {
- return this; // since CoreCLR's ExecutionContext is immutable, we don't need to create copies.
- }
-
- public void Dispose()
- {
- // For CLR compat only
- }
- }
-
- public struct AsyncFlowControl : IDisposable
- {
- private Thread _thread;
-
- internal void Initialize(Thread currentThread)
- {
- Debug.Assert(currentThread == Thread.CurrentThread);
- _thread = currentThread;
- }
-
- public void Undo()
- {
- if (_thread == null)
- {
- throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CannotUseAFCMultiple"));
- }
- if (Thread.CurrentThread != _thread)
- {
- throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_CannotUseAFCOtherThread"));
- }
-
- // An async flow control cannot be undone when a different execution context is applied. The desktop framework
- // mutates the execution context when its state changes, and only changes the instance when an execution context
- // is applied (for instance, through ExecutionContext.Run). The framework prevents a suppressed-flow execution
- // context from being applied by returning null from ExecutionContext.Capture, so the only type of execution
- // context that can be applied is one whose flow is not suppressed. After suppressing flow and changing an async
- // local's value, the desktop framework verifies that a different execution context has not been applied by
- // checking the execution context instance against the one saved from when flow was suppressed. In .NET Core,
- // since the execution context instance will change after changing the async local's value, it verifies that a
- // different execution context has not been applied, by instead ensuring that the current execution context's
- // flow is suppressed.
- if (!ExecutionContext.IsFlowSuppressed())
- {
- throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_AsyncFlowCtrlCtxMismatch"));
- }
- Contract.EndContractBlock();
-
- _thread = null;
- ExecutionContext.RestoreFlow();
- }
-
- public void Dispose()
- {
- Undo();
- }
-
- public override bool Equals(object obj)
- {
- return obj is AsyncFlowControl && Equals((AsyncFlowControl)obj);
- }
-
- public bool Equals(AsyncFlowControl obj)
- {
- return _thread == obj._thread;
- }
-
- public override int GetHashCode()
- {
- return _thread?.GetHashCode() ?? 0;
- }
-
- public static bool operator ==(AsyncFlowControl a, AsyncFlowControl b)
- {
- return a.Equals(b);
- }
-
- public static bool operator !=(AsyncFlowControl a, AsyncFlowControl b)
- {
- return !(a == b);
- }
- }
-}
-
-
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