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 WINAPI GetThreadPriority(
__in HANDLE hThread
);
|
Parameters
- hThread [in]
-
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 and Windows XP/2000: 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.
The thread's priority level is one of the following values.
| Return code/value | Description |
| THREAD_PRIORITY_ABOVE_NORMAL
1 | Priority 1 point above the priority class. |
| THREAD_PRIORITY_BELOW_NORMAL
-1 | Priority 1 point below the priority class. |
| THREAD_PRIORITY_HIGHEST
2 | Priority 2 points above the priority class. |
| THREAD_PRIORITY_IDLE
-15 | 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. |
| THREAD_PRIORITY_LOWEST
-2 | Priority 2 points below the priority class. |
| THREAD_PRIORITY_NORMAL
0 | Normal priority for the priority class. |
| THREAD_PRIORITY_TIME_CRITICAL
15 | 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.
Requirements
| Client | Requires Windows Vista, Windows XP, or Windows 2000 Professional. |
| Server | Requires Windows Server 2008, Windows Server 2003, or Windows 2000 Server. |
| Header | Declared in Winbase.h; include Windows.h. |
| Library | Use Kernel32.lib. |
| DLL | Requires Kernel32.dll. |
See Also
GetPriorityClass
OpenThread
Process and Thread Functions
Scheduling Priorities
SetPriorityClass
SetThreadPriority
Threads
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Build date: 8/7/2008