Wrote a Real-time Best Practices HOW TO #1710
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sharmeye
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May 14, 2024
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| #### 1.1 Trick events are computationally expensive. Use them judiciously. | ||
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| Trick events can provide a quick, easy, way to customize the behavior of a sim, based on some condition. But, because they require Python interpretation, they are slow. They are not intended for implementation of permanent sim functionality. If they are over used, they can seriously degrade simulation performance. So, take it easy with the events. |
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quick, easy, -> quick and easy
sharmeye
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May 14, 2024
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| #### 1.2 Disable Trick run-time components that your sim doesn't need. | ||
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| ```default_trick_sys.sm```, the file included at the top of any Trick ```S_define``` file defines numerous "modules" that provide functionality to a Trick sim. Whereas some of these modules ( like the Executive, MemoryManager, CommandLineArguments) are required for any Trick Simulation to function, many are optional. If the modules are not needed, then disabling them can improve simulation perfromance. |
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perfromance -> performance
sharmeye
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May 14, 2024
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| #### 1.3 Consider running Trick variable server clients and Sims on different machines. | ||
| Trick variable server clients communicate with a simulation via a TCP/IP connection. | ||
| The client process may, but isn't required to run on the same machine as your simulation process. On the same machine, both will competing for the same resources. This can degrade sim performance, especially when clients are rendering high-definition graphics. |
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may, but isn't required to -> may, but isn't required to,
sharmeye
reviewed
May 14, 2024
| SubmarineSimObject dyn; | ||
| ... | ||
| ``` | ||
| This job only transmits information. It doesn't effect the simulation, but does degrade real-time performance slightly. To disable it, we'll add the following to our input file: |
sharmeye
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May 14, 2024
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| #### 2.2 Try to reduce variation in job cycle times. | ||
| Realtime performance is largely about minimizing the worst case, rather than the average case. | ||
| The most well behaved job takes the same time, every time. |
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takes the same amount of time
sharmeye
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May 14, 2024
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| In an UMA architecture, as the number of CPUs increases, the higher tha chance that the system bus will become a bottle-neck. |
sharmeye
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May 14, 2024
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| # Trick Real-time Best Practices | |||
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Throughout document, alternating between real-time and realtime should be eliminated. Pick the one that you hate the least and roll with it
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changed all to realtime, except in the title of a referenced document.
hchen99
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May 14, 2024
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| Real world dynamic systems change in real time (the time that you and I experience). A simulated dynamic system changes in simulation-time. Simulation time begins at t=0, and runs until we stop it. Simulation time can elapse faster or slower than real-time. | ||
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| If we want to interact with a simulation as if it were real, we need to synchronize simulation time to real time. This requires that a simulation is capable of running at least as fast as real time. If it is incapable, then it can not be made to run in real time. |
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Do we want to use either real-time or real time consistently?
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Same as above issue. Fixed.
| <a id=frame-log-files></a> | ||
| #### Frame Log Files | ||
| Frame logging records the following data files in your sim’s RUN_ directory: | ||
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Might want to add log_timeline.csv and log_timeline_init.csv as in trick-dp section mentioned 5 data product xml files.
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Added descriptions to these files.
| |# | Name | Type | Units | Description | | ||
| |--:|:---- |:-----|:-----:|-------------| | ||
| | 1| ```sys.exec.out.time``` | double | seconds |Simulation Time | | ||
| | 2| ```trick_real_time.rt_sync.frame_time``` | double | seconds | This badly named parameter expresses the amount of time that the scheduled jobs in this frame took to execute. See: [figure](#figure-Real-time-under``-run)| |
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This figure link doesn't seem to work
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I think I've fixed all of the issues. Should be ready to merge. |
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Title says it