UnsatisfiedLinkError on dll load

[Bharath_M]

Hi Friends,

I have a sample piece of code in my application that loads a dll and use its methods...

My code runs fine for the very first time and native methods get invoked properly...

But when i try for the second time, loading dll fails with unsatisfiedlink error...if i quit and start my application, the dll load works for first time again and fails in future attempts...

I am aware that my dll is still loaded by classloader...but someone please help me to get rid of this by unloading dll each time my task is done...

Regards,
Bharath M

[JosAH]

Hi Friends,

I have a sample piece of code in my application that loads a dll and use its methods...

My code runs fine for the very first time and native methods get invoked properly...

But when i try for the second time, loading dll fails with unsatisfiedlink error...if i quit and start my application, the dll load works for first time again and fails in future attempts...

I am aware that my dll is still loaded by classloader...but someone please help me to get rid of this by unloading dll each time my task is done...

Regards,
Bharath M

Do you quit your Java program before you attempt to load your .dll again, or do you simply try to load it again in the same 'incarnation' of your Java program. Loading a .dll for a second (or third etc.) time shouldn't harm you because the documentation explicitly states: "If this method is called more than once with the same library name, the second and subsequent calls are ignored.".

kind regards,

Jos

[Bharath_M]

I quit my java program before i attempt to load my dll again...

[JosAH]

I quit my java program before i attempt to load my dll again...

So you run your program for the first time and everything runs ok; you try to run it again and the loading fails; you try to run it for a third time and everything is fine again, etc. etc. Is this assumption correct?

kind regards,

Jos

[Bharath_M]

Not really...It works for only the first time and fails on all of the future runs...

[JosAH]

Not really...It works for only the first time and fails on all of the future runs...

Ah, ok, my guess is that the OS is playing tricks on you: it doesn't unload the .dll when your application quits and no more references to the .dll exist. I don't know how to force MS Windows to immediately unload a .dll when it isn't needed anymore, sorry.

What happens if you wait a bit before you restart your application again?

kind regards,

Jos

[Bharath_M]

Yes... i observed occasionally today that if i wait for some time, i get rid of this error...but dont know wat exactly needs to be done to fix this...

[JosAH]

Yes... i observed occasionally today that if i wait for some time, i get rid of this error...but dont know wat exactly needs to be done to fix this...

Does your .dll use sockets or other resources that linger after you've closed your application?

kind regards,

Jos

[Bharath_M]

No, i dont use any such sockets with my dll....so there might not be any lingering sockets as you suspect...there is something else happening which am not aware...