Best practice for controlling plugin update times?

[TD22057]

I'm writing a plugin to read sensor data from the Open Hardware Monitor (OHM) application and am thinking about update efficiency issues. In some cases, there could be a lot of measure's using the same OHM app. I'm wondering what the best way to read/refresh the data from OHM is. The data comes from a windows WMI call. It seems like (no actual measurements) it should be more efficient to read all the sensors in a single call and then have the different measures just read their values from a data structure vs. having a WMI call get made for each sensor.

Some ideas:

- brute force. Make a WMI call for each update() call made to the plugin.

- If I knew what the update interval was for each measure, I could make a WMI call for the shortest one and then just have each update() call return the value that was read at the last update.

- In theory I could have a background thread that updates the sensor values at some interval and the meters would just read from them (this seems unnecessarily complicated).

- Internal update interval. The AdvancedCPU plugin checks it's own internal update clock and only updates values every 0.5 seconds. This seems like the simplest way to improve efficiency - make a single call to read every sensor value at some internal interval.

Any thoughts on the "right" way to do things would be greatly appreciated...

Ted

[poiru]

In this case, I think an internal update rate makes most sense. Perhaps once per second or maybe even slower is sufficient. If a user wants to improve efficiency, they can change the global Update= and/or add UpdateDivider= to all OHM measures.

I PM'd our local C++ wizard, let's see what he thinks.

[JamesAC]

Personally I would go with option 4, the internal update rate, that is the one i was using in something I was working on.

I would be interested to see what spx says though

[spx]

I agree "internal update interval", too. It would fit the purpose.

[TD22057]

OK - Thanks everyone.

Another question (since I have all this developer attention) - how do I include/use STL constructs in a plugin? I'm running VS C++ express 2008. If I build the example plugin, it builds fine. If I add a line:

#include <map>

after the other includes, I get a million errors when trying to build (shown below). I see there are plugins using STL includes but I can't figure out what the difference is between their setup and the example.

1>c:\program files (x86)\microsoft visual studio 9.0\vc\include\cstdlib(21) : error C2143: syntax error : missing '{' before ':'
1>c:\program files (x86)\microsoft visual studio 9.0\vc\include\cstdlib(21) : error C2059: syntax error : ':'
1>c:\program files (x86)\microsoft visual studio 9.0\vc\include\cstdlib(21) : error C2143: syntax error : missing '{' before ':'
1>c:\program files (x86)\microsoft visual studio 9.0\vc\include\cstdlib(21) : error C2059: syntax error : ':'

[spx]

Another question (since I have all this developer attention) - how do I include/use STL constructs in a plugin? I'm running VS C++ express 2008. If I build the example plugin, it builds fine. If I add a line:

#include <map>

after the other includes, I get a million errors when trying to build (shown below). I see there are plugins using STL includes but I can't figure out what the difference is between their setup and the example.

1>c:\program files (x86)\microsoft visual studio 9.0\vc\include\cstdlib(21) : error C2143: syntax error : missing '{' before ':'
1>c:\program files (x86)\microsoft visual studio 9.0\vc\include\cstdlib(21) : error C2059: syntax error : ':'
1>c:\program files (x86)\microsoft visual studio 9.0\vc\include\cstdlib(21) : error C2143: syntax error : missing '{' before ':'
1>c:\program files (x86)\microsoft visual studio 9.0\vc\include\cstdlib(21) : error C2059: syntax error : ':'

Rename filename. (.c to .cpp)
If file extension is ".c", VC treats as C language file.

[TD22057]

Rename filename. (.c to .cpp)
If file extension is ".c", VC treats as C language file.

Thanks. I knew it must be something simple like that.

Next question: I'm using Update2() since most of sensor value are floating point. I didn't implement a GetString function which from the docs is not necessary. However, when I try to import a skin, it gives me an error saying I need Update or GetString. What's the proper solution? Implement GetString() and convert the Update2 value to a string?

[TD22057]

Never mind. When I switched it to C++ I forgot to add extern "c" around the exports.

[TD22057]

Since I'm turning this into a general question thread, here's another one:

What's the best way to report error messages to the user? It's going to be pretty easy for some one using my plugin to misspell a sensor name and they won't get any data back. It would be nice if I could show an error dialog, message, etc when this happens. I have it configured to write something to the log file showing pass/fail, sensor values, etc but that seems like a pain to just debug a simple input problem.

[poiru]

I'd go with a messagebox for erros and LSLog() for others. Something like this: http://code.google.com/p/rainmeter/source/browse/trunk/Plugins/PluginSpeedFan/SpeedFanPlugin.cpp#134