Memory hole? - NSIS Forums

spanky
14th January 2004 01:03 UTC

Memory hole?
I'm not sure why but this example below will use upwards towards 90MB of memory within 20 mins. In my test I pointed the download file to something small, around 20K in size.
I've tested this bug(?) with various builds, including the latest CVS release.

-------------------------
Name "memoryhole"
OutFile "memoryhole.exe"
Caption "memoryhole"
SilentInstall silent

Section ""

foo:
NSISdl::download http://www.noname.com/poo.jpg $EXEDIR\outfile.exe
sleep 25
goto foo

SectionEnd
-------------------------

rainwater
14th January 2004 01:22 UTC

Unless its leaking memory, I don't see a bug since its an infinite loop.

spanky
14th January 2004 02:08 UTC

Originally posted by rainwater
Unless its leaking memory, I don't see a bug since its an infinite loop.

It uses more and more memory with each loop. That is a memory leak, is it not?!

Joel
14th January 2004 20:19 UTC

No, is not. Like rainwater said, you only have an endless loop, but it'll grab memory.
Leak is when you don't empty the space in the memory. In this case you just loading up.

spanky
15th January 2004 00:41 UTC

so why is it gobbling up memory and how can it be freed?

Joel
15th January 2004 01:10 UTC

mmm, because there's no exit for the loop.

spanky
15th January 2004 05:29 UTC

what you say makes no sense. I don't see why having "no exit for the loop" is a reason for this example to gobble 90MB+ in less than 20 mins.

Yathosho
15th January 2004 12:32 UTC

that's how IE works, and i think not NSIS is to blame for this ;)

Joost Verburg
15th January 2004 12:43 UTC

NSISdl does not use IE.

Joel
15th January 2004 20:47 UTC

Originally posted by spanky
what you say makes no sense. I don't see why having "no exit for the loop" is a reason for this example to gobble 90MB+ in less than 20 mins.

It's memory "usage", no leaking, of the Win32 APIs. Since there's no stop in the loop, the OS (Windows) works endless.

spanky
15th January 2004 23:34 UTC

ah, so the usage is keeping track of where it is in the loop?

Koen van de Sande
16th January 2004 16:04 UTC

Yes :)

kichik
16th January 2004 17:44 UTC

No, that's not supposed to happen. No API call should increase memory usage when used in a loop assuming its freeing function is also called in the loop.

spanky
17th January 2004 01:19 UTC

Originally posted by kichik
No, that's not supposed to happen. No API call should increase memory usage when used in a loop assuming its freeing function is also called in the loop.

so would this mean there is a bug in NSIS?

Joel
17th January 2004 04:58 UTC

It's not a NSIS bug. It's the computer working out with an endless loop.

Joost Verburg
17th January 2004 11:40 UTC

It is a bug in the NSISdl plug-in.

kichik
17th January 2004 17:42 UTC

Lobo, try:

loop:
sleep 1
goto loop

Joel
17th January 2004 19:15 UTC


Name "memoryleak"
OutFile "memoryleak.exe"
Caption "memoryleak"
SilentInstall silent

Section ""
Loop:
sleep 1
goto Loop
SectionEnd

The memory usage of the EXE still 2,188 KB. No overflow of the memory...

Joost Verburg
17th January 2004 22:35 UTC

Indeed. So there is something wrong with NSISdl.

Koen van de Sande
18th January 2004 12:39 UTC

I stand corrected then. I thought an infinite loop would start eating up the stack, but I guess it doesn't.

kichik
1st February 2004 18:56 UTC

The main leak is in your code. You forgot to Pop the returned value. This leaks 1KB each iteration of the loop. Other than that, there were some problems with NSISdl. Hopefully they were all fixed in the latest CVS version. See the change log for more details.