This procedure changes the priority of an item. Some items in the operating system are maintained in lists; for example, tasks and threads. Some lists are ordered by priority, with higher-priority items coming before lower-priority items. When the priority of an item in a list changes, the kernel automatically rearranges the list of items to reflect the new priority. The item is moved immediately before the first item whose priority is lower.
A task must own an item to change its priority. A task can change its own priority even if it does not own itself.
Arguments
i
The item number of the item whose priority to change.
newpri
The new priority for the item.
Return Value
The procedure returns the previous priority of the item or an error code if an error occurs.
Implementation
SWI implemented in kernel folio V20.
Associated Files
item.h
ANSI C Prototype
Notes
For certain item types, such as devices, the kernel may change the priority of an item to help optimize throughput.
Caveats
This function is not implemented for all known item types.