March 2017

How do I keep thread pool threads, or other threads in general, from competing with my render thread for CPU?

Raymond Chen March 9, 2017 Mar 9, 2017 03/9/17

Processor affinity lets you specify which processor or processors a thread can run on. This works for threads you control, but what about threads you don't control? Consider a game. You want your render thread to run with as little interference as possible because it is time-critical. You can set the processor affinity for the render thread ...

How do we improve the performance of conhost processes when we ping a bunch of servers?

Raymond Chen March 8, 2017 Mar 8, 2017 03/8/17

A customer had a program that launches many instances of the ping program in order to check the availability of a large number of servers. They found that each copy of ping comes with a copy of conhost.exe, and all these conhost processes degrade system performance by a factor of four. They were looking for guidance on how they could improve ...

Microspeak: to reason over

Raymond Chen March 7, 2017 Mar 7, 2017 03/7/17

Today's Microspeak is the phrase reason over. This API allows you to reason over the objects and relationships contained in the schema model generated by DACFx. To get value out of that data, we must be able to reason over it, tap into processing power to quickly analyze it and accelerate the insights. COMObject may be imported via tlbimp ...

Some internal developer chatter on a bug that caused your screen to turn black

Raymond Chen March 6, 2017 Mar 6, 2017 03/6/17

There was a bug in an internal build of Windows (let's call it build N) where if you were sufficiently unlucky, your screen would turn black and get stuck that way. The team responsible for the bug was busy working on a fix. They later reported that verification in their branch was successful and that the fix was awaiting (but had not received...

The case of the 32-bit program that tries to load a 64-bit DLL

Raymond Chen March 3, 2017 Mar 3, 2017 03/3/17

One of our escalation engineers wrote up an epic case study of a particular problem that he was able to solve. I'll retell the story here, but redacted, and significantly abbreviated. A customer reported that when their 32-bit program called IUpdateSearcher::BeginSearch, the resulting dialog box was empty. As in the dialog box had ...

What happens when you tell a Millennial to take pictures of a party

Raymond Chen March 2, 2017 Mar 2, 2017 03/2/17

I was a speaker at an internal Microsoft conference for field technical people, I offered my attendee party ticket to my team because I was unable to attend myself. My instructions to the person who got the ticket were "Take pictures." In retrospect, I should have been more specific, because he is a Millennial, and the pictures we got were of ...

Don’t forget to implement canonical names for verbs in your shell context menu extension

Raymond Chen March 2, 2017 Mar 2, 2017 03/2/17

A commonly-overlooked implementation detail of shell context menu extensions is the canonical verb, which is returned by the IContextMenu::GetCommandString method and which can be passed to IContextMenu::InvokeCommand. Canonical verbs permit your context menu to be consistently invoked programmatically, since they no ...

Want to include a gift message with your tires? Nice try.

Raymond Chen March 1, 2017 Mar 1, 2017 03/1/17

I learned that Costco online doesn't allow gift messages for car tires. Happy anniversary, honey! Disclaimer: Not actually my anniversary...

Why does my attempt to acquire an SRW lock block even though !locks report no locks held?

Raymond Chen March 1, 2017 Mar 1, 2017 03/1/17

A customer asked for some help debugging a problem with their application: We have an application that synchronizes access to resources by using SRW locks rather than critical sections. We have traced execution in the debugger up to the point at which we're about to call AcquireSRWLockShared. Trying to step over the call in WinDbg ...

The Old New Thing

March 2017 - Page 3 of 3 - The Old New Thing