These enums, externs, and typedefs of the task package are used by one
  or more classes but they are not members of any particular class.

1 - Print Function Values

  The following values are used in the verbosity argument to print
  member functions:

  0		Requests a brief report

 CHAIN		Requests information about tasks on the object's
 		remember chain, and about other objects on the
 		object's o_next chain

  STACK		Requests information about the run-time stack

  VERBOSE	Requests detailed information on the class object

2 - Queue Mode Values

  The following values are used by the qhead and qtail classes for
  managing queues:

 EMODE		Generates a run-time error if full on enqueue or empty
 		on dequeue

 WMODE		Suspends task execution if full on enqueue or empty on
 		dequeue

  ZMODE		Returns NULL if full on enqueue or empty on dequeue

3 - Exception Codes

  The following codes handle exceptions for the classes indicated:

  E_OLINK = 1		Cannot delete an object with a remembered task
 			(object class)

  E_ONEXT = 2		Cannot delete an object which is on a list
 			(object class)

  E_GETEMPTY = 3		Cannot get an object from an empty queue
 			(qhead class)

  E_PUTOBJ = 4		Cannot put an object into a full queue (qtail
 			class)

  E_PUTFULL = 5		Cannot put an object into a queue if the object
 			is on another queue (qtail class)

  E_BACKOBJ = 6		Cannot putback an object into a queue if the
 			object is on another queue (qhead class)

  E_BACKFULL = 7		Cannot putback an object into a full queue
 			(qhead class)

  E_SETCLOCK = 8		Cannot set the clock after it has advanced
 			past 0 (sched class)

  E_CLOCKIDLE = 9	Cannot advance the clock when clock_task is
 			RUNNING or TERMINATED (sched class)

  E_RESTERM = 10		Cannot resume a TERMINATED task (sched class)

  E_RESRUN = 11		Cannot resume a RUNNING task (sched class)

  E_NEGTIME = 12		Cannot delay a negative amount of time (sched
 			class)

  E_RESOBJ = 13		Cannot resume a task or timer if it is already
 			on another queue (sched class)

  E_HISTO = 14		Cannot construct a histogram with less than 1
 			bucket or the left not less than the right
 			(histogram class)

  E_STACK = 15		Cannot extend stack (task class)

  E_STORE = 16		Cannot allocate more memory (object, qhead,
 			qtail, and task classes)

  E_TASKMODE = 17	Cannot create a task with a mode other than
 			DEDICATED or SHARED (task class)

  E_TASKDEL = 18		Cannot delete a task which is IDLE or RUNNING
 			(task class)

  E_TASKPRE = 19		Cannot preempt a task which is IDLE or
 			TERMINATED (task class)

  E_TIMERDEL = 20	Cannot delete a timer which is IDLE or RUNNING
 			(timer class)

  E_SCHTIME = 21		Cannot execute something at a time which
 			already passed (sched class)

  E_SCHOBJ = 22		Cannot use class sched other than as a base
 			class (sched class)

  E_QDEL = 23		Cannot delete a queue which has an object in
 			the queue (qhead and qtail classes)

  E_RESULT = 24		Cannot call result() on thistask (task class)

  E_WAIT = 25		Cannot call wait() on thistask (task class)

  E_FUNCS = 26		Encountered an unexpected exception or access
                         violation

  E_FRAMES = 27		Not used in DEC C++

  E_REGMASK = 28		Not used in DEC C++

  E_FUDGE_SIZE = 29	Not used in DEC C++

  E_NO_HNDLR = 30	Cannot handle a signal for which there is no
 			handler (Interrupt_handler class)

  E_BADSIG = 31		Cannot handle a signal with an invalid signal
 			number (Interrupt_handler class)

  E_LOSTHNDLR = 32	Cannot handle a signal which is not on a stack
 			of them for the given signal
 			(Interrupt_handler class)

  E_TASKNAMEOVERRUN = 33 Not used in DEC C++

4 - Maximum stack size

  To keep track of the maximum stack size that can be printed by the
  function task::print(), set the _hwm (high-water marking) data
  member to a nonzero value before creation of the first task.

  Declaration:

  extern int _hwm