This article was previously published under Q187884
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Calling CoCreateInstance on multiple threads at the same time causes thecomputer to not respond (hang) for long periods of time. No desktopactivity can be performed during this time. PerfMon logs during the timethe 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 computeris not responding. This problem was originally identified when hosting ASPpages that issue CoCreateInstance requests. When under stress, the computerwould cease responding. CoCreateInstance requests would fail with theE_OUTOFMEMORY error leading up to the time when the computer quitsresponding.
The problem is caused by a shortage in the LPC resource pool. All threadsthat request LPC pool storage are in a wait (a two-minute timeout) for afree pool request to post that pool storage is available. Explorer.exethreads that need LPC pool storage will also wait. Since no free poolrequests come through, all threads wait for two minutes, giving theappearance of a system hang. When the two minute timeout expires, the poolis expanded and all threads begin running again.
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, click the following article number to view the article in theMicrosoft Knowledge Base:
152734 How to Obtain the Latest Windows NT 4.0 Service Pack
Microsoft has confirmed that this is 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.