typedef enum { ... } SilcTaskPriority;

    Task priorities. Tasks may be registered with different priorities.
    This type defines the different task priorities. The priorities
    behaves same for all type of tasks, fd tasks, timeout tasks and
    generic tasks.

    typedef enum {
      /* Lowest priority. The task is scheduled to run after its timeout
         has expired only and only when every other task with higher priority 
         has already been run. For non-timeout tasks this priority behaves
         same way. Life is not fair for tasks with this priority. */
      SILC_TASK_PRI_LOW      = 0,
    
      /* Normal priority that is used mostly in SILC. This is priority that
         should always be used unless you specificly need some other priority.
         The scheduler will run this task as soon as its timeout has expired.
         For non-timeout tasks this priority behaves same way. Tasks are run 
         in FIFO (First-In-First-Out) order. */
      SILC_TASK_PRI_NORMAL,
    } SilcTaskPriority;