Re: Two Services trying to load a System library in same JVM

Francisco Mourao wrote:
> Hi there,
> I have a monitor application that launches in the same JVM two instances of
> the same service each one monitoring a serial port. Namely, Monitor1 and
> Monitor2 are two instances of same service MonitorService with entries
> name=M1 and name=M2 respectively.
> 
> The problem is that MonitorService tries to load a system library with
> System.loadLibrary(...). The first instance to be initialized loads
> successfully but when the second service tries to load the library an
> exception is thrown saying that the library is already loaded. 
> 
> This must be a very common problem I suppose. So I think there must be some
> work around for this. Or not? 
> 
> I didn't want to launch a VM for each instance of MonitorService... i can
> have up to  20 instances...

The easiest thing to do is build a new start.jar that includes a class-path 
reference to the serial comms library's jar.  Then, it will be loaded once, from 
the system classloader, instead of from each services preferred classloader.

I am assuming you are using com.sun.jini.start to start your services.

Gregg Wonderly

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