CoCreateInstance Under Stress on Multiple Threads at the Same Time Causes Long Hangs or Returns Failure

ID: Q187884

The information in this article applies to:

SYMPTOMS

Calling CoCreateInstance on multiple threads at the same time causes the computer to not respond (hang) for long periods of time. No desktop activity can be performed during this time. PerfMon logs during the time the computer is not responding show no signs that the computer is stressed. The idle thread has more than 95 percent of the CPU time while the computer is not responding. This problem was originally identified when hosting ASP pages that issue CoCreateInstance requests. When under stress, the computer would cease responding. CoCreateInstance requests would fail with the E_OUTOFMEMORY error leading up to the time when the computer quits responding.


CAUSE

The problem is caused by a shortage in the LPC resource pool. All threads that request LPC pool storage are in a wait (a two-minute timeout) for a free pool request to post that pool storage is available. Explorer.exe threads that need LPC pool storage will also wait. Since no free pool requests come through, all threads wait for two minutes, giving the appearance of a system hang. When the two minute timeout expires, the pool is expanded and all threads begin running again.


RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base:

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack


STATUS

Microsoft has confirmed this to be a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.

Additional query words: CoCreateInstance stress hang E_OUTOFMEMORY 


Keywords          : NT4SP4Fix kbbug4.00 kbfix4.00.sp4 
Version           : WinNT:4.0
Platform          : winnt 
Issue type        : kbbug

Last Reviewed: April 10, 1999