private static ThreadPriority MapFromOSPriority(OSThreadPriority priority)
{
switch (priority)
{
case OSThreadPriority.Idle:
case OSThreadPriority.Lowest:
return(ThreadPriority.Lowest);
case OSThreadPriority.BelowNormal:
return(ThreadPriority.BelowNormal);
case OSThreadPriority.Normal:
return(ThreadPriority.Normal);
case OSThreadPriority.AboveNormal:
return(ThreadPriority.AboveNormal);
case OSThreadPriority.Highest:
case OSThreadPriority.TimeCritical:
return(ThreadPriority.Highest);
case OSThreadPriority.ErrorReturn:
Debug.Fail("GetThreadPriority failed");
return(ThreadPriority.Normal);
default:
return(ThreadPriority.Normal);
}
}
private static ThreadPriority MapFromOSPriority(OSThreadPriority priority)
{
if (priority <= OSThreadPriority.Lowest)
{
// OS thread priorities in the [Idle,Lowest] range are mapped to ThreadPriority.Lowest
return(ThreadPriority.Lowest);
}
switch (priority)
{
case OSThreadPriority.BelowNormal:
return(ThreadPriority.BelowNormal);
case OSThreadPriority.Normal:
return(ThreadPriority.Normal);
case OSThreadPriority.AboveNormal:
return(ThreadPriority.AboveNormal);
case OSThreadPriority.ErrorReturn:
Debug.Fail("GetThreadPriority failed");
return(ThreadPriority.Normal);
}
// Handle OSThreadPriority.ErrorReturn value before this check!
if (priority >= OSThreadPriority.Highest)
{
// OS thread priorities in the [Highest,TimeCritical] range are mapped to ThreadPriority.Highest
return(ThreadPriority.Highest);
}
Debug.Fail("Unreachable");
return(ThreadPriority.Normal);
}
private ThreadPriority GetPriority()
{
if (_osHandle.IsInvalid)
{
// The thread has not been started yet; return the value assigned to the Priority property.
// Race condition with setting the priority or starting the thread is OK, we may return an old value.
return(_priority);
}
// The priority might have been changed by external means. Obtain the actual value from the OS
// rather than using the value saved in _priority.
OSThreadPriority osPriority = Interop.mincore.GetThreadPriority(_osHandle);
return(MapFromOSPriority(osPriority));
}
