The IO_WORKITEM structure is an opaque structure that describes a work item for a system worker thread.
Any work item that is allocated by IoAllocateWorkItem must be freed by IoFreeWorkItem. Any memory that is initialized by IoInitializeWorkItem must be uninitialized by IoUninitializeWorkItem before it can be freed.
For more information about work items, see System Worker Threads.
Build date: 11/16/2013