GetThreadPriority function (processthreadsapi.h)
Retrieves the priority value for the specified thread. This value, together with the priority class of the thread's process, determines the thread's base-priority level.
Syntax
int GetThreadPriority(
[in] HANDLE hThread
);
Parameters
[in] hThread
A handle to the thread.
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: The handle must have the THREAD_QUERY_INFORMATION access right.
Return value
If the function succeeds, the return value is the thread's priority level.
If the function fails, the return value is THREAD_PRIORITY_ERROR_RETURN. To get extended error information, call GetLastError.
Windows Phone 8.1: This function will always return THREAD_PRIORITY_NORMAL.
The thread's priority level is one of the following values.
| Return code/value | Description |
|---|---|
|
Priority 1 point above the priority class. |
|
Priority 1 point below the priority class. |
|
Priority 2 points above the priority class. |
|
Base priority of 1 for IDLE_PRIORITY_CLASS, BELOW_NORMAL_PRIORITY_CLASS, NORMAL_PRIORITY_CLASS, ABOVE_NORMAL_PRIORITY_CLASS, or HIGH_PRIORITY_CLASS processes, and a base priority of 16 for REALTIME_PRIORITY_CLASS processes. |
|
Priority 2 points below the priority class. |
|
Normal priority for the priority class. |
|
Base-priority level of 15 for IDLE_PRIORITY_CLASS, BELOW_NORMAL_PRIORITY_CLASS, NORMAL_PRIORITY_CLASS, ABOVE_NORMAL_PRIORITY_CLASS, or HIGH_PRIORITY_CLASS processes, and a base-priority level of 31 for REALTIME_PRIORITY_CLASS processes. |
If the thread has the REALTIME_PRIORITY_CLASS base class, this function can also return one of the following values: -7, -6, -5, -4, -3, 3, 4, 5, or 6. For more information, see Scheduling Priorities.
Remarks
Every thread has a base-priority level determined by the thread's priority value and the priority class of its process. The operating system uses the base-priority level of all executable threads to determine which thread gets the next slice of CPU time. Threads are scheduled in a round-robin fashion at each priority level, and only when there are no executable threads at a higher level will scheduling of threads at a lower level take place.
For a table that shows the base-priority levels for each combination of priority class and thread priority value, refer to the SetPriorityClass function.
Windows 8.1 and Windows Server 2012 R2: This function is supported for Windows Store apps.
Windows Phone 8.1:Windows Phone Store apps may call this function but it has no effect.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows XP [desktop apps | UWP apps] |
| Minimum supported server | Windows Server 2003 [desktop apps | UWP apps] |
| Target Platform | Windows |
| Header | processthreadsapi.h (include Windows.h on Windows Server 2003, Windows Vista, Windows 7, Windows Server 2008 Windows Server 2008 R2) |
| Library | Kernel32.lib; WindowsPhoneCore.lib on Windows Phone 8.1 |
| DLL | Kernel32.dll; KernelBase.dll on Windows Phone 8.1 |