Applies to: desktop apps only
Retrieves timing information for the specified thread.
Syntax
BOOL WINAPI GetThreadTimes( __in HANDLE hThread, __out LPFILETIME lpCreationTime, __out LPFILETIME lpExitTime, __out LPFILETIME lpKernelTime, __out LPFILETIME lpUserTime );
Parameters
- hThread [in]
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A handle to the thread whose timing information is sought. The handle must have the THREAD_QUERY_INFORMATION or THREAD_QUERY_LIMITED_INFORMATION access right. For more information, see Thread Security and Access Rights.
Windows Server 2003 and Windows XP: The handle must have the THREAD_QUERY_INFORMATION access right. - lpCreationTime [out]
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A pointer to a FILETIME structure that receives the creation time of the thread.
- lpExitTime [out]
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A pointer to a FILETIME structure that receives the exit time of the thread. If the thread has not exited, the content of this structure is undefined.
- lpKernelTime [out]
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A pointer to a FILETIME structure that receives the amount of time that the thread has executed in kernel mode.
- lpUserTime [out]
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A pointer to a FILETIME structure that receives the amount of time that the thread has executed in user mode.
Return value
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
Remarks
All times are expressed using FILETIME data structures. Such a structure contains two 32-bit values that combine to form a 64-bit count of 100-nanosecond time units.
Thread creation and exit times are points in time expressed as the amount of time that has elapsed since midnight on January 1, 1601 at Greenwich, England. There are several functions that an application can use to convert such values to more generally useful forms; see Time Functions.
Thread kernel mode and user mode times are amounts of time. For example, if a thread has spent one second in kernel mode, this function will fill the FILETIME structure specified by lpKernelTime with a 64-bit value of ten million. That is the number of 100-nanosecond units in one second.
To retrieve the number of CPU clock cycles used by the threads, use the QueryThreadCycleTime function.
Requirements
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Minimum supported client | Windows XP |
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Minimum supported server | Windows Server 2003 |
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Header |
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Library |
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DLL |
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See also
- FILETIME
- FileTimeToDosDateTime
- FileTimeToLocalFileTime
- FileTimeToSystemTime
- OpenThread
- Process and Thread Functions
- Threads
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Build date: 3/7/2012
[DllImport("kernel32.dll", CharSet=CharSet.Auto, SetLastError=true)]
public static extern bool GetThreadTimes(IntPtr handle, out long creation, out long exit, out long kernel, out long user);
<DllImport("kernel32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Public Shared Function GetThreadTimes(ByVal handle As IntPtr, <Out> ByRef creation As Long, <Out> ByRef [exit] As Long, <Out> ByRef kernel As Long, <Out> ByRef user As Long) As Boolean
End Function
Note that the method by which kernel and user time is measured and accumulated for each thread makes it necessary for one to take samples over a long period of time (seconds) for the output of this routine to be accurate. The granularity of the measurement used here is in the 10mS arena, so sample times over 100 times that should yield sufficiently accurate results for most users.
If you're looking for profiler-type operation (sampling hundreds if not thousands of times in a second), this is NOT the method to use.
In other words, do not:
loop sleep( 30 ) GetThreadTimes() End loop
Instead do this, or the equivalent (this is SIMPLIFIED code -- Sleep( 1000 ) is not usually a good idea)
loop
sleep( 1000 )
GetThreadTimes()
End loop
-e