Memory leak... somewhere.

Hi,

I just discovered any kind of memory leak on my computer. I was running three FlashFXP instances on three different servers, all connections were disconnected. Over night, today when I went home from work, I discovered that 32 GB of 32 GB RAM are in use and Windows is quite slow. After some investigation I discovered, that FlashFXP is causing this memory leak... I don't know how or why, but I'm sure that FlashFXP caused this. All FlashFXP instances were not useable - they were lagging extremely - and I even could not close them. After killing the FlashFXP proccesses over the task manager my RAM usage got back to about 7 GB.

Sadly I can't give you any more details what happend: Just that FlashFXP was eating up my RAM. After restarting FlashFXP everything seems to be fine. Maybe there is a memory leak when the connection to a server gets lost for a longer time?

And finally: Thank you very much for this awesome software. I enjoy using it since many years

Best regards,
Patrik

Hello,

Thank you for your report.

What specific version/build of FlashFXP are you using?

What type of transfers were you performing, uploading, downloading, or site to site transfers (direct or indirect) ?

Were you connected to the servers over FTP, FTP+TLS, or SFTP?

Do you have session logging enabled?
Options > Preferences > General > Logging

Are you using FlashFXP in English or another language, which?

Version: 5.2.0 build 3912
Actions: None. All instances were disconnected from the server (for a longer time, because of timeout)
Used server type: SFTP
Logging: Not enabled
Language: English

I did find a small memory leak (or so I thought I did) but it turned out to be a false positive, the memory was freed after the memory leak checking code had run. Simple solution was to explicitly free the memory before hand, which eliminated the false positive.

Unfortunately this doesn't solve your problem or even come close to explain it, it was a one time variable containing about 20 bytes of data used for a object that is created on startup and freed when the program exits.

After about 8 hours of thorough testing using multiple detection methods and memory/resource allocations I have not been able to find any detectable leaks. It's impossible to say FlashFXP is 100% leak free but during a multitude of different stress tests I was not able to observe any leaks.

Now FlashFXP clones the windows file manager shell, this means that any 3rd party shell extensions used in windows file manager are also automatically loaded into the FlashFXP process memory space. If you have a 3rd party shell extension installed that is faulty or poorly written it could have a negative impact on FlashFXP, if it leaks memory, or whatever the case may be it would in turn give a false indication that FlashFXP is the one leaking memory/resources.

Another possibilities... related to a low memory situation while FlashFXP is running.

1. The memory used by FlashFXP was swapped to disk (swapfile) upon restoring FlashFXP the memory is accessed and windows needs to read it from disk back into ram, this can cause high cpu load while waiting for the memory to be available. (Even when memory is not low, I have seen situations with FlashFXP being minimized to the system tray for several days and then trying to restore FlashFXP triggers a large CPU spike followed by long delay before FlashFXP finally appears)

2. FlashFXP malfunctioned because it was unable to allocate memory to complete some unknown operation, this puts the program in an unknown state which may have lead to unexpected results.

Originally Posted by bigstar

Now FlashFXP clones the windows file manager shell, this means that any 3rd party shell extensions used in windows file manager are also automatically loaded into the FlashFXP process memory space. If you have a 3rd party shell extension installed that is faulty or poorly written it could have a negative impact on FlashFXP, if it leaks memory, or whatever the case may be it would in turn give a false indication that FlashFXP is the one leaking memory/resources.

You were absolutely right. Because of your guess I finally could reproduce the behaviour and find the origin application which caused this memory leak issue. When I turn the 3rd party application in the settings Off, the memory leak appears... FlashFXP raises up to 20% CPU usage and leaks memory... till I kill FlashFXP.

I'm so sorry for wasting your time! Are you interested in more details, e.g. which application? Maybe you could prevent this memory leak in FlashFXP somehow - if you want. I'm going to contact the developer of the other application, which causes this leak, anyway.

Thanks for your time!

Yes, if you can provide me with the name of the program and version you have installed, I will investigate it further.

AquaSnap, Version 1.17.1 (trial version available)

Thank you, I will investigate this app