/**

@page LEVEL3 Realtime Synchronization Requirements
  
<b>LEVEL4</b> Trick shall be capable of synchronizing simulation time to a
real-time clock. 

<b>LEVEL4</b> Trick shall be capable of running non-real-time.
[@anchor rt_non_real_time rt_non_real_time] 

<b>LEVEL4</b> Trick shall provide the capability to switch between real-time and
non-real-time execution.
[@anchor rt_enable rt_enable]
[@anchor rt_disable rt_disable]

<b>LEVEL4</b> Trick shall detect when the current simulation job execution frame
takes longer than the real-time frame (overrun).
[@anchor rt_detect_overrun rt_detect_overrun]

<b>LEVEL4</b> Trick shall provide the option to respond to simulation overruns by

<b>LEVEL5</b> continuing to next frame of execution,

<b>LEVEL5</b> freezing, [@anchor rt_overrun_freeze rt_overrun_freeze]

<b>LEVEL5</b> or terminating.  [@anchor rt_overrun_terminate rt_overrun_terminate] 

<b>LEVEL4</b> The overrun criteria to cause a response shall be either:
[@anchor rt_overrun_criteria rt_overrun_criteria] 

<b>LEVEL5</b> A single large overrun of a user specified size (in seconds), or 

<b>LEVEL5</b> a user specified number of overruns is detected

<b>LEVEL4</b> Trick shall detect when the current simulation job execution frame is
equal to or shorter than the real-time frame (underrun).
[@anchor rt_detect_underrun rt_detect_underrun]

<b>LEVEL4</b> Trick shall wait for real-time to catch up to the 
simulation time before starting the next frame of execution during an underrun.

<b>LEVEL4</b> Trick shall provide the option to release the processor (sleep) during
an underrun.

*/