Track Performance of Distributed Systems

[Roy Lachapelle]

In the Downloadable examples, Masocode.zip, the java code for Syslog.java
has a method:

public static synchronized Syslog instance() {
if (instance != null)
instance = new Syslog();
return instance;
}

Shouldn't that be ' if (instance == null) ' to perform as a 'hybrid' singleton
?
(I say 'hybrid' because the constructor is not private...)

And even if a new instance was desired each time, then the instance needs
to be
initialized somewhere, possibly in the constructor.

-Roy

[Chris P.]

"Roy Lachapelle" <Roy.Lachapelle@Travelersla.com> wrote:
>
>In the Downloadable examples, Masocode.zip, the java code for Syslog.java
>has a method:
>
>public static synchronized Syslog instance() {
> if (instance != null)
> instance = new Syslog();
> return instance;
> }
>
>Shouldn't that be ' if (instance == null) ' to perform as a 'hybrid'
singleton
>?
>(I say 'hybrid' because the constructor is not private...)
>
>And even if a new instance was desired each time, then the instance needs
>to be
>initialized somewhere, possibly in the constructor.
>
>-Roy

thanks for your question. I've alerted Brian to this, and he should be posting
an answer shortly.

/cp
devX.com

[Brian Maso]

[From the author, Brian Maso]

Yes, Roy is exactly correct. I should have checked this part of the code,
which was not exercised in the sample program.

The idea of the single instance would be for an application that has maby
different components sending syslog messages off. Rather than have each one
create an independent Syslog instance (with all the resource expence associated),
they can all just share a single stateless Syslog instance available through
the static method.

Of course the static method would have to be written correctly...

Thanks for finding that, Roy. A corrected version of the zip file with be
available soon.

Brian Maso

"Roy Lachapelle" <Roy.Lachapelle@Travelersla.com> wrote:
>
>In the Downloadable examples, Masocode.zip, the java code for Syslog.java
>has a method:
>
>public static synchronized Syslog instance() {
> if (instance != null)
> instance = new Syslog();
> return instance;
> }
>
>Shouldn't that be ' if (instance == null) ' to perform as a 'hybrid'
singleton
>?
>(I say 'hybrid' because the constructor is not private...)
>
>And even if a new instance was desired each time, then the instance needs
>to be
>initialized somewhere, possibly in the constructor.
>
>-Roy