Driver memory leak?

[bubnenkoff]

Hi! I can't find the reason of why my app do not release memory. Here is topic http://forum.dlang.org/post/aluvxaltjkoojxuthswc@forum.dlang.org

I checked most of possible variants and even tried to call GC.collect();, but app still continue eat and do not release memory.

My code do not use nothing expect your driver. So I can assume that the driver is reason (but I am not sure).

The size of data set with I am working is about 400k rows.

Could you please do any test on your PC?

I tried to do call result.close(); in every loop iteration.

	foreach(item; getTablesGPSSensorList) // iterate pairs gps-sensor. getTablesGPSSensorList is array of Tuples (tables of DB).
	{			
		string itemName = format("GPS: %s | Sensor: %s", item.gps, item.sensor);
		ResultRange result = mysqlconnection.query(sqlquery.replace(`historygps_xxx`, item.gps).replace(`historysensor_xxx`, item.sensor));

[bubnenkoff]

Yes, it's seems that there is issue in driver. It's do not release memory...
My full code https://gist.github.com/bubnenkoff/f6c0a0b7088292e25186dc030846b70f

[Abscissa]

I'm afraid that without a complete (all-inclusive), reduced test case that I can just compile & run locally straight out-of-the-box, there isn't a whole lot I can personally do to dig into this.

However, for various reasons, I strongly suspect you're hitting issues with false pointers. This seems especially likely because (based on #100) you appear to be using a 32-bit exe for handling large amounts of data. Since D's garbage collector is not yet a "precise GC", processing lots of data in a 32-bit build makes false pointers (and therefore memory leaks) very likely.

I recommend building your program as a 64-bit instead of 32-bit, and see if that helps alleviate the problem. In theory, you should be able to do this by simply using the "-m64" flag when you run DMD. However, getting 64-bit support working right on Windows can sometimes be a little tricky, so if you have any troubles building a 64-bit D application, ask around on the newsgroup (I'm usually on Linux and was still using 32-bit back when I was developing on Windows, so I'm afraid I wouldn't be much help with that.)

[bubnenkoff]

Thanks! I will try on monday!

[bubnenkoff]

You are right!!
I checked. If build app on Windows with:
dub -a=x86_64 all works fine even error #100

[Abscissa]

FWIW, the reason #100 goes away when building for 64-bit is because optlink only supports 32-bit (it's also Windows-only). So when building for 64-bit on Windows, optlink isn't used at all, the Microsoft linker is used instead.