Update EventSource.xml

[msnilsen]

Clamp fileTime to > Jan 1st, 1601

Summary

DateTime.MinValue causes arg.ToFileTimeUtc() to throw an exception.

When using mc.exe to translate a manifest specifying a Data element with inType="win:SYSTEMTIME" outType="xs:dateTime" to c# code, the generated code can handle DateTime.MinValue and it clamps the value to 0b11110000.

However, when using EventRegister to convert an EventSource class to a manifest, the manifest it builds uses inType="win:FILETIME" for a parameter of type DateTime. Then, when using mc.exe to translate that manifest to c#, it generates the code specified in this documentation:

long argFileTime = arg.ToFileTime();
userDataPtr[0].DataPointer = (UInt64)(&argFileTime);
userDataPtr[0].Size = (uint)(sizeof(long));

Which causes the code using this class to throw an exception instead of acting how it did previously, which was having the datetime clamped to the earliest systemtime.

Fixes #9246

[learn-build-service-prod]

Learn Build status updates of commit b8142a3:

✅ Validation status: passed

File	Status	Preview URL	Details
xml/System.Diagnostics.Tracing/EventSource.xml	✅Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

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Issue Details

---

Clamp fileTime to > Jan 1st, 1601

Summary

DateTime.MinValue causes arg.ToFileTimeUtc() to throw an exception.

When using mc.exe to translate a manifest specifying a Data element with inType="win:SYSTEMTIME" outType="xs:dateTime" to c# code, the generated code can handle DateTime.MinValue and it clamps the value to 0b11110000.

However, when using EventRegister to convert an EventSource class to a manifest, the manifest it builds uses inType="win:FILETIME" for a parameter of type DateTime. Then, when using mc.exe to translate that manifest to c#, it generates the code specified in this documentation:

long argFileTime = arg.ToFileTime();
userDataPtr[0].DataPointer = (UInt64)(&argFileTime);
userDataPtr[0].Size = (uint)(sizeof(long));

Which causes the code using this class to throw an exception instead of acting how it did previously, which was having the datetime clamped to the earliest systemtime.

Fixes #9246

Author:	msnilsen
Assignees:	-
Labels:	area-System.Diagnostics.Tracing, community-contribution
Milestone:	-

[tarekgh]

CC @davmason

[noahfalk]

@msnilsen - Thanks for investigating the issue and contributing a fix to the docs. Very much appreciated!

[learn-build-service-prod]

Learn Build status updates of commit e4b7c36:

✅ Validation status: passed

File	Status	Preview URL	Details
xml/System.Diagnostics.Tracing/EventSource.xml	✅Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[davmason]

Thanks! Looks good to me outside of Tarek's feedback