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ASYNC_DISKPOOL_LOCK

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Description:

This wait type is when a thread is synchronizing with other threads that help manage long-duration file operations, such as creating/deleting files, zeroing out new files, or encrypting a file for TDE.

(Books Online description: “Occurs when there is an attempt to synchronize parallel threads that are performing tasks such as creating or initializing a file.”)

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Added in SQL Server version:

Pre-2005/2005

Removed in SQL Server version:

N/A

Extended Events wait_type value:

The map_key value in sys.dm_xe_map_values is 112 in 2008 and 2008 R2, and 116 in 2012 and 2014 RTM. After 2014 RTM, you must check the DMV to get the latest value as some map_key values have changed in later builds.

Other information:

I have not seen this wait type be a noticeable contention point.

Known occurrences in SQL Server (list number matches call stack list):

  1. Waiting to acquire the lock

And other similar call stacks.

Abbreviated call stacks (list number matches known occurrences list):

  1. SOS_Task::PostWait+9e
    EventInternal<SuspendQueueSLock>::Wait+1fb
    AutoAsynchronousDiskPoolLock::Get+94
    AsynchronousDiskWorker::ThreadRoutine+61
    SubprocEntrypoint+a7f
    SOS_Task::Param::Execute+21e
    SOS_Scheduler::RunTask+a8