Questions tagged [jvm]
A Java virtual machine (JVM) is a virtual machine that can execute Java bytecode. It is the code execution component of the Java platform.
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Implementation of variables in JVM / Java
I know that a lot of interpreted higher level languages like to abstract a lot of things and therefore cannot directly be compared with lower level constructs.
For example in some languages primitive ...
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How to access version of a Java application programmatically when running from an IDE?
As far as I understand, the best practice for programmatic access to the version of a Java application is to:
Specify version via build system (e.g. in Gradle).
Include the version string as a ...
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Why are some languages called platform dependent if I can always share the source code?
I was reading about erlang when I read that it is platform-independent, using BEAM as the VM, now I understand that a VM compiles the byte code to machine code and this makes that language machine-...
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To show the difference between system VMs and JVMs
I am trying to draw diagrams that show the difference between system virtual machines and Java virtual machines.
The first two images looks correct to me. But I don't know how to draw the third.
...
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Are JVM thread dumps a security concern?
When building parallelized applications using Java, a developer sometimes finds himself with a thread being blocked indefinitely because of a four-year-old bug in the spring-bean-web-rest-foo-bar-...
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Converting Java code run by dependency to native code
Is it, at least theoretically, possible to convert a Java application into native code that can be run by something else written in Java? One example of this could be a Minecraft Spigot server. You ...
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How's .NET multi-platform approach different than Java's back in the days? [closed]
TL;DR
How is the new .NET approach to being a multi platform framework
better than what Java did long ago?
What are the key differences in the implementation?
What are the advantages and disadvantages ...
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Different types of heap in java
I was faced with this question recently for the different types of heap memory available in Java.
I couldn't find much information online. Are there different types of heap memory available in Java ?...
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What the fastest way to pass large data between JVMs?
I have 2 JVMs on the same machine that I want to pass about 1Mb of (serializable) data between ideally in under 5 ms.
Under load, using HTTP to localhost takes about 70ms average.
I tried hazelcast, ...
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How is memory modeled in projects like Apache Spark or Druid?
In the past couple of months I've worked with both Apache Spark and Druid for some projects. As I've gone through the process of learning how to use these tools, I've spent some time reading through ...
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Beginner: Can Java source code be executed by Java Virtual Machine? Or not directly?
Im in my first week of college majoring in computer science. Can java source code be directly executed by JVM?
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How do Virtual Machines allocate memory?
If I want to allocate a struct in C,
#include<stdio.h>
typedef struct container {
int i;
} Container;
int main() {
Container *ptr_to_container;
ptr_to_container = (Container *) ...
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what happens at Java interpreter level when IncompatibleClassChangeError is thrown?
I am a noob at JVM internals.
Can someone explain what happens at Java interpreter level when IncompatibleClassChangeError is thrown?
I am facing an issue similar to the one described here: https:...
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What is a "shaded" Java dependency?
JVM developer here. Lately I've seen banter on IRC chat rooms and even in my own office about so-called "shaded" Java libraries. The context of the use will be something like:
"Such and so provides ...
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What stops C from being compiled/interpreted/JIT'ed?
Java is often praised for its amazing portability, which I presume is because of the JVM. My question is what stops C from being being compiled/interpreted/JIT'ed.., if so, C can also be write once ...
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Why is the Java bytecode instruction set not orthogonal?
Section 2.11.1 of the JVM 8 Specification includes the words:
In other words, the instruction set is intentionally not orthogonal.
From my perspective, that implies that the Java bytecode ...
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Changing the Garbage Collector on your JVM [closed]
My understanding is that the JVM specification only defines the behavior of a garbage collector, but does not provide implementation details. This means it is up to the JVM implementation to build the ...
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If Scala runs on the JVM, how can Scala do things that Java seemingly cannot? [duplicate]
I just learned about Scala yesterday, and I'd like to learn more about it. One thing that came to mind, however, from reading the Scala website is that if Scala runs on the JVM, then how is it ...
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Does the JVM's Garbage Collector clean the entire JVM HotSpot memory (C-Heap, Java Heap and Permanent Generation space) or just Java Heap?
I know that the JVM has some JVM HotSpot memory which is further divided into three areas:
Java Heap
Permanent Generation Space
Native Heap (C-Heap)
I know that Java has automatic garbage collection ...
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JVM memory and zero-copy (de)serialization
I am trying to understand the JVM memory model. In particular, I would like to understand whether it would be feasible to have zero-copy (de)serialization libraries, such as Cap'n Proto or FlatBuffers....
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When I create an object, is fresh memory allocated to both instance fields and methods or only to instance fields
I have a following class
class Student{
int rollNumber;
int marks;
public void setResult(int rollNumber, int marks){
this.rollNumber=rollNumber;
this.marks=marks;
}
public void ...
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Is it possible to have a single code base for a desktop GUI and a web application?
The required user interface is fairly simple; basically, two tables that "interact with each other", e.g. certain rows in one table get highlighted when a row in the other is clicked, plus maybe a ...
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Pattern matching in Clojure vs Scala
What are the key differences between pattern matching in these two languages? I am not referring to syntax, but capability, implementation details, range of use cases and necessity.
Scala ...
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Is Java Bytecode interpreted? [closed]
The definition of interpretation (correct me if I'm wrong) is parsing code like so:
1- Translate currently parsed line to some intermediate language. 2- Run the translated line. 3- Move to the next ...
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What is the advantage of a programmers VM apart from portability [duplicate]
I can understand the benefits of Java running on a JVM. Portability. Nice simple reason. But I have always been puzzled as to why Microsoft brought out their own version of a JVM - .NET. C# is ...
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