SilcTask silc_schedule_task_add(SilcSchedule schedule, SilcUInt32 fd,
                                    SilcTaskCallback callback, 
                                    void *context, 
                                    long seconds, long useconds, 
                                    SilcTaskType type, 
                                    SilcTaskPriority priority);

    Registers a new task to the scheduler. This same function is used
    to register all types of tasks. The `type' argument tells what type
    of the task is. Note that when registering non-timeout tasks one
    should also pass 0 as timeout, as the timeout will be ignored anyway. 
    Also, note, that one cannot register timeout task with 0 timeout.
    There cannot be zero timeouts, passing zero means no timeout is used
    for the task and SILC_TASK_FD is used as default task type in
    this case.

    The `schedule' is the scheduler context. The `fd' is the file
    descriptor of the task. On WIN32 systems the `fd' is not actual
    file descriptor but some WIN32 event handle. On WIN32 system the `fd'
    may be a socket created by the SILC Net API routines, WSAEVENT object
    created by Winsock2 network routines or arbitrary WIN32 HANDLE object.
    On Unix systems the `fd' is always the real file descriptor.

    The `callback' is the task callback that will be called when some
    event occurs for this task. The `context' is sent as argument to
    the task `callback' function. For timeout tasks the callback is
    called after the specified timeout has elapsed.

    If the `type' is SILC_TASK_TIMEOUT then `seconds' and `useconds'
    may be non-zero.  Otherwise they should be zero. The `priority'
    indicates the priority of the task.

    It is always safe to call this function in any place. New tasks
    may be added also in task callbacks, and in multi-threaded environment
    in other threads as well.