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Merged
merged 2 commits into from
Jul 20, 2025
Merged

Cleanup uses of Interlocked.CompareExchange<object> #117858

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6d4e98b
Cleanup uses of Interlocked.CompareExchange<object>
jkotas Jul 20, 2025
1995dde
Add usings
jkotas Jul 20, 2025
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3 changes: 2 additions & 1 deletion src/coreclr/System.Private.CoreLib/src/System/MulticastDelegate.CoreCLR.cs
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Expand Up @@ -9,6 +9,7 @@
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Runtime.Serialization;
using System.Threading;

namespace System
{
Expand Down Expand Up @@ -144,7 +145,7 @@ private bool InvocationListEquals(MulticastDelegate d)

private static bool TrySetSlot(object?[] a, int index, object o)
{
if (a[index] == null && Threading.Interlocked.CompareExchange<object?>(ref a[index], o, null) == null)
if (a[index] == null && Interlocked.CompareExchange(ref a[index], o, null) == null)
return true;

// The slot may be already set because we have added and removed the same method before.
Expand Down
15 changes: 3 additions & 12 deletions src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeAssembly.cs
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Expand Up @@ -34,7 +34,7 @@ internal sealed partial class RuntimeAssembly : Assembly

#endregion

internal IntPtr GetUnderlyingNativeHandle() { return m_assembly; }
internal IntPtr GetUnderlyingNativeHandle() => m_assembly;

private sealed class ManifestResourceStream : UnmanagedMemoryStream
{
Expand All @@ -52,17 +52,8 @@ internal unsafe ManifestResourceStream(RuntimeAssembly manifestAssembly, byte* p
// NOTE: no reason to override Write(Span<byte>), since a ManifestResourceStream is read-only.
}

internal object SyncRoot
{
get
{
if (m_syncRoot == null)
{
Interlocked.CompareExchange<object?>(ref m_syncRoot, new object(), null);
}
return m_syncRoot;
}
}
internal object SyncRoot =>
m_syncRoot ?? Interlocked.CompareExchange(ref m_syncRoot, new object(), null) ?? m_syncRoot;

public override event ModuleResolveEventHandler? ModuleResolve
{
Expand Down
3 changes: 2 additions & 1 deletion src/coreclr/nativeaot/System.Private.CoreLib/src/System/Delegate.cs
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Expand Up @@ -9,6 +9,7 @@
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Runtime.Serialization;
using System.Threading;

using Internal.Reflection.Augments;
using Internal.Runtime;
Expand Down Expand Up @@ -465,7 +466,7 @@ private unsafe Delegate NewMulticastDelegate(Wrapper[] invocationList, int invoc

private static bool TrySetSlot(Wrapper[] a, int index, Delegate o)
{
if (a[index].Value == null && System.Threading.Interlocked.CompareExchange(ref a[index].Value, o, null) == null)
if (a[index].Value == null && Interlocked.CompareExchange(ref a[index].Value, o, null) == null)
return true;

// The slot may be already set because we have added and removed the same method before.
Expand Down
20 changes: 3 additions & 17 deletions ...m.Collections.Immutable/src/System/Collections/Immutable/ImmutableDictionary_2.Builder.cs
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Expand Up @@ -4,6 +4,7 @@
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Threading;

namespace System.Collections.Immutable
{
Expand Down Expand Up @@ -56,11 +57,6 @@ public sealed class Builder : IDictionary<TKey, TValue>, IReadOnlyDictionary<TKe
/// </summary>
private int _version;

/// <summary>
/// The object callers may use to synchronize access to this collection.
/// </summary>
private object? _syncRoot;

/// <summary>
/// Initializes a new instance of the <see cref="ImmutableDictionary{TKey, TValue}.Builder"/> class.
/// </summary>
Expand Down Expand Up @@ -251,18 +247,8 @@ ICollection IDictionary.Values
/// </summary>
/// <returns>An object that can be used to synchronize access to the <see cref="ICollection"/>.</returns>
[DebuggerBrowsable(DebuggerBrowsableState.Never)]
object ICollection.SyncRoot
{
get
{
if (_syncRoot == null)
{
Threading.Interlocked.CompareExchange<object?>(ref _syncRoot, new object(), null);
}

return _syncRoot;
}
}
object ICollection.SyncRoot =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;

/// <summary>
/// Gets a value indicating whether access to the <see cref="ICollection"/> is synchronized (thread safe).
Expand Down
20 changes: 3 additions & 17 deletions .../System.Collections.Immutable/src/System/Collections/Immutable/ImmutableList_1.Builder.cs
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Expand Up @@ -4,6 +4,7 @@
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Threading;

namespace System.Collections.Immutable
{
Expand Down Expand Up @@ -46,11 +47,6 @@ public sealed class Builder : IList<T>, IList, IReadOnlyList<T>
/// </summary>
private int _version;

/// <summary>
/// The object callers may use to synchronize access to this collection.
/// </summary>
private object? _syncRoot;

/// <summary>
/// Initializes a new instance of the <see cref="Builder"/> class.
/// </summary>
Expand Down Expand Up @@ -1159,18 +1155,8 @@ bool ICollection.IsSynchronized
/// </summary>
/// <returns>An object that can be used to synchronize access to the <see cref="ICollection"/>.</returns>
[DebuggerBrowsable(DebuggerBrowsableState.Never)]
object ICollection.SyncRoot
{
get
{
if (_syncRoot == null)
{
System.Threading.Interlocked.CompareExchange<object?>(ref _syncRoot, new object(), null);
}

return _syncRoot;
}
}
object ICollection.SyncRoot =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;
#endregion
}
}
Expand Down
20 changes: 3 additions & 17 deletions ...ections.Immutable/src/System/Collections/Immutable/ImmutableSortedDictionary_2.Builder.cs
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Expand Up @@ -4,6 +4,7 @@
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Threading;

namespace System.Collections.Immutable
{
Expand Down Expand Up @@ -59,11 +60,6 @@ public sealed class Builder : IDictionary<TKey, TValue>, IReadOnlyDictionary<TKe
/// </summary>
private int _version;

/// <summary>
/// The object callers may use to synchronize access to this collection.
/// </summary>
private object? _syncRoot;

/// <summary>
/// Initializes a new instance of the <see cref="Builder"/> class.
/// </summary>
Expand Down Expand Up @@ -262,18 +258,8 @@ ICollection IDictionary.Values
/// </summary>
/// <returns>An object that can be used to synchronize access to the <see cref="ICollection"/>.</returns>
[DebuggerBrowsable(DebuggerBrowsableState.Never)]
object ICollection.SyncRoot
{
get
{
if (_syncRoot == null)
{
Threading.Interlocked.CompareExchange<object?>(ref _syncRoot, new object(), null);
}

return _syncRoot;
}
}
object ICollection.SyncRoot =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;

/// <summary>
/// Gets a value indicating whether access to the <see cref="ICollection"/> is synchronized (thread safe).
Expand Down
20 changes: 3 additions & 17 deletions ...em.Collections.Immutable/src/System/Collections/Immutable/ImmutableSortedSet_1.Builder.cs
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Expand Up @@ -4,6 +4,7 @@
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Threading;

namespace System.Collections.Immutable
{
Expand Down Expand Up @@ -51,11 +52,6 @@ public sealed class Builder : IReadOnlyCollection<T>, ISet<T>, ICollection
/// </summary>
private int _version;

/// <summary>
/// The object callers may use to synchronize access to this collection.
/// </summary>
private object? _syncRoot;

/// <summary>
/// Initializes a new instance of the <see cref="Builder"/> class.
/// </summary>
Expand Down Expand Up @@ -505,18 +501,8 @@ bool ICollection.IsSynchronized
/// </summary>
/// <returns>An object that can be used to synchronize access to the <see cref="ICollection"/>.</returns>
[DebuggerBrowsable(DebuggerBrowsableState.Never)]
object ICollection.SyncRoot
{
get
{
if (_syncRoot == null)
{
Threading.Interlocked.CompareExchange<object?>(ref _syncRoot, new object(), null);
}

return _syncRoot;
}
}
object ICollection.SyncRoot =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;
#endregion
}
}
Expand Down
15 changes: 2 additions & 13 deletions src/libraries/System.Diagnostics.TraceSource/src/System/Diagnostics/Switch.cs
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Expand Up @@ -25,25 +25,14 @@ public abstract class Switch
private bool _initializing;
private volatile string? _switchValueString = string.Empty;
private readonly string _defaultValue;
private object? _initializedLock;

private static readonly List<WeakReference<Switch>> s_switches = new List<WeakReference<Switch>>();
private static int s_LastCollectionCount;
private StringDictionary? _attributes;

private object InitializedLock
{
get
{
if (_initializedLock == null)
{
object o = new object();
Interlocked.CompareExchange<object?>(ref _initializedLock, o, null);
}
private object InitializedLock =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;

return _initializedLock;
}
}

/// <devdoc>
/// <para>Initializes a new instance of the <see cref='System.Diagnostics.Switch'/>
Expand Down
15 changes: 2 additions & 13 deletions src/libraries/System.Private.CoreLib/src/System/TimeZone.cs
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Expand Up @@ -15,19 +15,8 @@ public abstract class TimeZone
private static volatile TimeZone? currentTimeZone;

// Private object for locking instead of locking on a public type for SQL reliability work.
private static object? s_InternalSyncObject;
private static object InternalSyncObject
{
get
{
if (s_InternalSyncObject == null)
{
object o = new object();
Interlocked.CompareExchange<object?>(ref s_InternalSyncObject, o, null);
}
return s_InternalSyncObject;
}
}
private static object InternalSyncObject =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;

protected TimeZone()
{
Expand Down
2 changes: 1 addition & 1 deletion src/libraries/System.Private.Xml.Linq/src/System/Xml/Linq/XContainer.cs
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Expand Up @@ -75,7 +75,7 @@ public XNode? LastNode
XText t = new XText(s);
t.parent = this;
t.next = t;
Interlocked.CompareExchange<object>(ref content, t, s);
Interlocked.CompareExchange(ref content, t, s);
}
return (XNode)content;
}
Expand Down
16 changes: 2 additions & 14 deletions src/libraries/System.Private.Xml/src/System/Xml/Schema/XmlSchemaSet.cs
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Expand Up @@ -56,20 +56,8 @@ public class XmlSchemaSet
private XmlSchemaObjectTable? _typeExtensions;

//Thread safety
private object? _internalSyncObject;
internal object InternalSyncObject
{
get
{
if (_internalSyncObject == null)
{
object o = new object();
Interlocked.CompareExchange<object?>(ref _internalSyncObject, o, null);
}

return _internalSyncObject;
}
}
internal object InternalSyncObject =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;

//Constructors

Expand Down
15 changes: 2 additions & 13 deletions src/libraries/System.Text.Encoding.CodePages/src/System/Text/DBCSCodePageEncoding.cs
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Expand Up @@ -225,19 +225,8 @@ protected virtual unsafe void CleanUpEndBytes(char* chars)
}

// Private object for locking instead of locking on a public type for SQL reliability work.
private static object? s_InternalSyncObject;
private static object InternalSyncObject
{
get
{
if (s_InternalSyncObject == null)
{
object o = new object();
Interlocked.CompareExchange<object?>(ref s_InternalSyncObject, o, null);
}
return s_InternalSyncObject;
}
}
private static object InternalSyncObject =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;

// Read in our best fit table
protected override unsafe void ReadBestFitTable()
Expand Down
15 changes: 2 additions & 13 deletions src/libraries/System.Text.Encoding.CodePages/src/System/Text/DecoderBestFitFallback.cs
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Expand Up @@ -47,19 +47,8 @@ internal sealed class InternalDecoderBestFitFallbackBuffer : DecoderFallbackBuff
private readonly InternalDecoderBestFitFallback _oFallback;

// Private object for locking instead of locking on a public type for SQL reliability work.
private static object? s_InternalSyncObject;
private static object InternalSyncObject
{
get
{
if (s_InternalSyncObject == null)
{
object o = new object();
Interlocked.CompareExchange<object?>(ref s_InternalSyncObject, o, null);
}
return s_InternalSyncObject;
}
}
private static object InternalSyncObject =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;

// Constructor
public InternalDecoderBestFitFallbackBuffer(InternalDecoderBestFitFallback fallback)
Expand Down
15 changes: 2 additions & 13 deletions src/libraries/System.Text.Encoding.CodePages/src/System/Text/EncoderBestFitFallback.cs
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Expand Up @@ -47,19 +47,8 @@ internal sealed class InternalEncoderBestFitFallbackBuffer : EncoderFallbackBuff
private int _iSize;

// Private object for locking instead of locking on a public type for SQL reliability work.
private static object? s_InternalSyncObject;
private static object InternalSyncObject
{
get
{
if (s_InternalSyncObject == null)
{
object o = new object();
Interlocked.CompareExchange<object?>(ref s_InternalSyncObject, o, null);
}
return s_InternalSyncObject;
}
}
private static object InternalSyncObject =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;

// Constructor
public InternalEncoderBestFitFallbackBuffer(InternalEncoderBestFitFallback fallback)
Expand Down
15 changes: 2 additions & 13 deletions src/libraries/System.Text.Encoding.CodePages/src/System/Text/SBCSCodePageEncoding.cs
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Expand Up @@ -129,19 +129,8 @@ protected override unsafe void LoadManagedCodePage()
}

// Private object for locking instead of locking on a public type for SQL reliability work.
private static object? s_InternalSyncObject;
private static object InternalSyncObject
{
get
{
if (s_InternalSyncObject == null)
{
object o = new object();
Interlocked.CompareExchange<object?>(ref s_InternalSyncObject, o, null);
}
return s_InternalSyncObject;
}
}
private static object InternalSyncObject =>
field ?? Interlocked.CompareExchange(ref field, new object(), null) ?? field;

// Read in our best fit table
protected override unsafe void ReadBestFitTable()
Expand Down
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