does delay in calling clojure from java happen only once ?
I use clojure more and more in production. To use it even more there, I need to be certain about the answer of the following question. My experiments lead me to the conjecture, that the answer is yes. But a proof can only be given by someone, who is familiar with clojure's implementation of which I have no clue. Thanks for your help !: The question is concerned with calling clojure from Java. I have a bunch of clojure stuff, which I compiled to byte code with the techniques described at http://clojure.org/compilation I made an archive A of the result. I have Java code, that uses things from A. Now: The first time something from A is called, there is a little delay. Afterwards there is no delay. Is it true, that, in a given JVM, only the very first call to something in A, will cause a delay ? -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: does delay in calling clojure from java happen only once ?
This has nothing to do directly with Clojure :) The JVM needs to load the class(es) involved. It involves obtaining the class files from disk or cache if lucky (an already opened jar file ?). Then some wiring has to be done to insure that the references needed from the class(es) are met, After these steps then optimizations can kick in so future calls are optimized if necessary. The Clojure merely spits out classes like the Java compiler does. Luc I use clojure more and more in production. To use it even more there, I need to be certain about the answer of the following question. My experiments lead me to the conjecture, that the answer is yes. But a proof can only be given by someone, who is familiar with clojure's implementation of which I have no clue. Thanks for your help !: The question is concerned with calling clojure from Java. I have a bunch of clojure stuff, which I compiled to byte code with the techniques described at http://clojure.org/compilation I made an archive A of the result. I have Java code, that uses things from A. Now: The first time something from A is called, there is a little delay. Afterwards there is no delay. Is it true, that, in a given JVM, only the very first call to something in A, will cause a delay ? -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -- Softaddictslprefonta...@softaddicts.ca sent by ibisMail from my ipad! -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: does delay in calling clojure from java happen only once ?
Thank you, for your answer. It doesn't convince me, though. I am well aware of the class loading mechanism of the JVM. But if I compile against, say guava-12.0.jar (beautiful stuff by the way), and use those classes at runtime, there is no delay in using them whatsoever. At least not a delay of nearly a second on my machine, the first time I use bytecode generated by clojure. I am quite sure, that the bytecode generated by clojure, initializes some sort of Runtime for itself, the first time it is called. My question is, does this happen more than once ? Furthermore clojure does not spit out classes. It spits out bytecode. Heinz. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: does delay in calling clojure from java happen only once ?
Ah, do you compile your Clojure code to Java prior to using it (AOT compilation) ? If not, you must add the clojure compilation time to spit out the class(es) byte code. Here we deliver AOTed components so there's no compilation overhead, we do this for other reasons than this very small overhead. Of course this will occur only once. Luc Thank you, for your answer. It doesn't convince me, though. I am well aware of the class loading mechanism of the JVM. But if I compile against, say guava-12.0.jar (beautiful stuff by the way), and use those classes at runtime, there is no delay in using them whatsoever. At least not a delay of nearly a second on my machine, the first time I use bytecode generated by clojure. I am quite sure, that the bytecode generated by clojure, initializes some sort of Runtime for itself, the first time it is called. My question is, does this happen more than once ? Furthermore clojure does not spit out classes. It spits out bytecode. Heinz. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -- Softaddictslprefonta...@softaddicts.ca sent by ibisMail from my ipad! -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: does delay in calling clojure from java happen only once ?
Yes, I do compile my clojure code ahead of time (AOT) to byte code. Does that mean, that your, ahead of time compiled clojure code, has no noticeable delay, when you first call it ? If in the middle of the lifetime of an app, this delay happens, i can not consider it small, if 1 requests are waiting to be served. Heinz. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: does delay in calling clojure from java happen only once ?
Compared to Java, not noticeable if any. We run our app in production on cluster of small computers. We replaced component written mostly in Java by Clojure equivalents without any degradation in service time. We used clojure from java a number of times using Java callable interfaces generated in Clojure (gen-class). Now it's the other way around. They're might be a bigger overhead if you call your code through the RT class instead of using generated APIs. Luc Yes, I do compile my clojure code ahead of time (AOT) to byte code. Does that mean, that your, ahead of time compiled clojure code, has no noticeable delay, when you first call it ? If in the middle of the lifetime of an app, this delay happens, i can not consider it small, if 1 requests are waiting to be served. Heinz. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en -- Softaddictslprefonta...@softaddicts.ca sent by ibisMail from my ipad! -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: does delay in calling clojure from java happen only once ?
Hm. I do have the feeling, that we do not understand each other.
Code is always unambigous.
I give an example, and give my question another run.
(ns p.x
(:gen-class
:methods [ ^{:static true} [f [] String] ]))
(defn -f [] hello, world)
Fire up a REPL, make sure, p/x.clj is in your classpath, as well as
classes (the default value of *compile-path*) and do
user= (compile p.x)
Go out of the repl, cd into classes and do a
$ jar cf a.jar *
package e;
import p.x;
public final class E {
public static void main(String[] args) {
for (int i = 0; i 100; ++i) {
System.out.println(x.f());
}
}
Fire up the java compiler (javac) on that Java source code, making sure,
that
he can find a.jar.
Now run E with the java launcher, making sure than a.jar and clojure.jar
are in its classpath.
Something like so:
$ java -cp a.jar:clojure.jar:./classes e.E
Observation:
---
The first hello world, takes a second or so to appear.
The 99 following are coming super fast, like always.
Question:
--
1. Am I doing something wrong or disadvantegous, and that
is an explanation for the delay ?
2. If not, does this delay happen only once in a given JVM ?
Thanks for your help.
Heinz.
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Re: does delay in calling clojure from java happen only once ?
The following makes it clearer:
package e;
import p.x;
public final class E {
public static void main(String[] args) {
System.out.println(before);
for (int i = 0; i 100; ++i) {
System.out.println(x.f());
}
}
Now: After launching, the string `before' gets printed (JVM up),
and *then* there is delay, before the first `hello, world'.
Jetzt aber.
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Re: does delay in calling clojure from java happen only once ?
It's the time to get all the related classes loaded needed to support the
Clojure
code and yes it's a one time cost. The first reference to x gets this triggered.
Luc
The following makes it clearer:
package e;
import p.x;
public final class E {
public static void main(String[] args) {
System.out.println(before);
for (int i = 0; i 100; ++i) {
System.out.println(x.f());
}
}
Now: After launching, the string `before' gets printed (JVM up),
and *then* there is delay, before the first `hello, world'.
Jetzt aber.
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Re: does delay in calling clojure from java happen only once ?
Yes, Clojure has a runtime which is initialized the first time you call any Clojure code. The initialization never happens more than once. -S -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
Re: does delay in calling clojure from java happen only once ?
Ah, cool ! Thank you very much for this insider knowledge, Mr. Sierra !!! Great. That means more clojure in production. Hurrah !!! Thanks again. Heinz. -- You received this message because you are subscribed to the Google Groups Clojure group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
