Clarify CompareExchange behavior (#10181)

* Clarify CompareExchange behavior

* Update overload text

Author: richlander

xml/System.Threading/Interlocked.xml

@@ -507,7 +507,7 @@
         <AssemblyVersion>4.1.0.0</AssemblyVersion>
       </AssemblyInfo>
       <Docs>
-        <summary>Compares two values for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two values for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
       </Docs>
     </MemberGroup>
     <Member MemberName="CompareExchange">
@@ -540,7 +540,7 @@
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two 8-bit unsigned integers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two 8-bit unsigned integers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>To be added.</remarks>
         <exception cref="T:System.NullReferenceException">The address of <paramref name="location1" /> is a <see langword="null" /> pointer.</exception>
@@ -596,7 +596,7 @@
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two double-precision floating point numbers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two double-precision floating point numbers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[  
@@ -651,7 +651,7 @@
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two 16-bit unsigned integers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two 16-bit unsigned integers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>To be added.</remarks>
         <exception cref="T:System.NullReferenceException">The address of <paramref name="location1" /> is a <see langword="null" /> pointer.</exception>
@@ -712,7 +712,7 @@
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two 32-bit signed integers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two 32-bit signed integers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[  
@@ -789,7 +789,7 @@
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two 64-bit signed integers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two 64-bit signed integers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[  
@@ -858,7 +858,7 @@
         <param name="location1">The destination <see cref="T:System.IntPtr" />, whose value is compared with the value of <paramref name="comparand" /> and possibly replaced by <paramref name="value" />.</param>
         <param name="value">The <see cref="T:System.IntPtr" /> that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The <see cref="T:System.IntPtr" /> that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two platform-specific handles or pointers for equality and, if they are equal, replaces the first one.</summary>
+        <summary>Compares two platform-specific handles or pointers for equality and, if they are equal, replaces the first one, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[  
@@ -936,7 +936,7 @@
         <param name="location1">The destination object that is compared by reference with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The object that replaces the destination object if the reference comparison results in equality.</param>
         <param name="comparand">The object that is compared by reference to the object at <paramref name="location1" />.</param>
-        <summary>Compares two objects for reference equality and, if they are equal, replaces the first object.</summary>
+        <summary>Compares two objects for reference equality and, if they are equal, replaces the first object, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[  
@@ -994,7 +994,7 @@ If `comparand` and the object in `location1` are equal by reference, then `value
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two 8-bit signed integers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two 8-bit signed integers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>To be added.</remarks>
         <exception cref="T:System.NullReferenceException">The address of <paramref name="location1" /> is a <see langword="null" /> pointer.</exception>
@@ -1051,7 +1051,7 @@ If `comparand` and the object in `location1` are equal by reference, then `value
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two single-precision floating point numbers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two single-precision floating point numbers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[  
@@ -1112,7 +1112,7 @@ If `comparand` and the object in `location1` are equal by reference, then `value
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two 16-bit signed integers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two 16-bit signed integers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>To be added.</remarks>
         <exception cref="T:System.NullReferenceException">The address of <paramref name="location1" /> is a <see langword="null" /> pointer.</exception>
@@ -1158,7 +1158,7 @@ If `comparand` and the object in `location1` are equal by reference, then `value
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two 32-bit unsigned integers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two 32-bit unsigned integers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>To be added.</remarks>
         <exception cref="T:System.NullReferenceException">The address of <paramref name="location1" /> is a <see langword="null" /> pointer.</exception>
@@ -1204,7 +1204,7 @@ If `comparand` and the object in `location1` are equal by reference, then `value
         <param name="location1">The destination, whose value is compared with <paramref name="comparand" /> and possibly replaced.</param>
         <param name="value">The value that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The value that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two 64-bit unsigned integers for equality and, if they are equal, replaces the first value.</summary>
+        <summary>Compares two 64-bit unsigned integers for equality and, if they are equal, replaces the first value, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>To be added.</remarks>
         <exception cref="T:System.NullReferenceException">The address of <paramref name="location1" /> is a <see langword="null" /> pointer.</exception>
@@ -1248,7 +1248,7 @@ If `comparand` and the object in `location1` are equal by reference, then `value
         <param name="location1">The destination <see cref="T:System.UIntPtr" />, whose value is compared with the value of <paramref name="comparand" /> and possibly replaced by <paramref name="value" />.</param>
         <param name="value">The <see cref="T:System.UIntPtr" /> that replaces the destination value if the comparison results in equality.</param>
         <param name="comparand">The <see cref="T:System.UIntPtr" /> that is compared to the value at <paramref name="location1" />.</param>
-        <summary>Compares two platform-specific handles or pointers for equality and, if they are equal, replaces the first one.</summary>
+        <summary>Compares two platform-specific handles or pointers for equality and, if they are equal, replaces the first one, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>To be added.</remarks>
         <exception cref="T:System.NullReferenceException">The address of <paramref name="location1" /> is a <see langword="null" /> pointer.</exception>
@@ -1326,7 +1326,7 @@ If `comparand` and the object in `location1` are equal by reference, then `value
         <param name="location1">The destination, whose value is compared by reference with <paramref name="comparand" /> and possibly replaced. This is a reference parameter (<see langword="ref" /> in C#, <see langword="ByRef" /> in Visual Basic).</param>
         <param name="value">The value that replaces the destination value if the comparison by reference results in equality.</param>
         <param name="comparand">The value that is compared by reference to the value at <paramref name="location1" />.</param>
-        <summary>Compares two instances of the specified reference type <paramref name="T" /> for reference equality and, if they are equal, replaces the first one.</summary>
+        <summary>Compares two instances of the specified reference type <paramref name="T" /> for reference equality and, if they are equal, replaces the first one, as an atomic operation.</summary>
         <returns>The original value in <paramref name="location1" />.</returns>
         <remarks>
           <format type="text/markdown"><![CDATA[