PREEMPTIVE_OS_CREATEDIRECTORY

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Description:

This wait type is when a thread is calling the Windows CreateDirectory function.

(Books Online description: N/A)

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Added in SQL Server version:

2008

Removed in SQL Server version:

N/A

Extended Events wait_type value:

The map_key value in sys.dm_xe_map_values is 445 in 2008 and 2008 R2, 493 in 2012, and 509 in 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.

Note that when a thread calls out to Windows, the thread changes from non-preemptive (SQL Server controls the thread) to preemptive (Windows controls the thread) mode. The thread’s state will be listed as RUNNING, as SQL Server doesn’t know what Windows is doing with the thread.

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

1. Creating the directory to hold the FILESTREAM log (in this case, as part of creating a database that has a FILESTREAM filegroup)
2. Creating a per-rowset directory in the FILESTREAM data container (in this case, as part of creating a table that has a FILESTREAM column)
3. Creating a per-column directory in a per-rowset directory in the FILESTREAM data container (in this case, as part of inserting a row that has FILESTREAM data)

And other similar call stacks.

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

1. SOS_Task::PopWait+0xb1
   AutoSwitchPreemptive::~AutoSwitchPreemptive+0x95
   FsLogMgr::Init+0x22c
   STREAMFCB::DownLevelInit+0x58
   STREAMFCB::Startup+0x143
   StreamFileMgr::AddStreamFile+0x766
   AttachAllStreamFiles+0xf5
   CStmtCreateDB::CreateLocalDatabaseFragment+0x9dc
   DBDDLAgent::CreateDatabase+0xf7
   CStmtCreateDB::XretExecute+0xdc1
   CMsqlExecContext::ExecuteStmts<1,1>+0x427
   CMsqlExecContext::FExecute+0xa43
   CSQLSource::Execute+0x86c
   process_request+0xa57
   process_commands+0x4a3
   SOS_Task::Param::Execute+0x21e
   SOS_Scheduler::RunTask+0xab
2. SOS_Task::PopWait+0xb1
   AutoSwitchPreemptive::~AutoSwitchPreemptive+0x95
   FsDoHandler::CreateDirectoryDownLevel+0x755
   FsDoHandler::CreateDirectoryW+0x33
   CFsRowset::AddColumn+0x82
   SECreateRowset+0xe7d
   DDLAgent::SECreateRowsets+0x11d7
   CIndexDDL::CreateRowsets+0xb26
   CIndexDDL::CreateEmptyHeap+0xff
   CTableCreate::CreateRelation+0xa16
   CTableCreate::LCreateImpl+0xef4
   CStmtCreateTable::XretCreateTableExecute+0x506
   CXStmtCreateTableDDL::XretExecute+0x3b
   CMsqlExecContext::ExecuteStmts<1,1>+0x427
   CMsqlExecContext::FExecute+0xa43
   CSQLSource::Execute+0x86c
   process_request+0xa57
   process_commands+0x4a3
   SOS_Task::Param::Execute+0x21e
   SOS_Scheduler::RunTask+0xab
3. SOS_Task::PopWait+0xb1
   AutoSwitchPreemptive::~AutoSwitchPreemptive+0x95
   StreamFileMgr::CreateDirectoryW+0x154
   StreamFileMgr::CreateDataFile+0x9b
   StreamFileMgr::DoCreateStreamFile+0xe0
   AsynchronousDiskAction::ExecuteDeferredAction+0xbf
   AsynchronousDiskWorker::ThreadRoutine+0x15c
   SubprocEntrypoint+0xa7f
   SOS_Task::Param::Execute+0x21e
   SOS_Scheduler::RunTask+0xab