Java's AtomicInteger class
java.util.concurrent.atomic.AtomicInteger was new in Java 1.5
Questions tagged [atomicinteger]
121 questions
0
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0 answers
NPE when using ThreadLocal + AtomicLong in Java
I'm initializing using public static ThreadLocal count = new ThreadLocal<>();
How do I use AtomicLong method for count? The below throws a NPE:
count.get().addAndGet(records.size());
NoName
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0
votes
1 answer
AtomicInteger vs synchronized block
I have a problem where I need to synchronize access to array of integers in java. My code looks something like this.
Class X {
int[] counters = new int[100];
Object lock = new Object ();
void increment (int idx){
…
grk939
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1 answer
Removing negative values when variable is an atomic vector
I have a large dataset of a survey (originally a Stata(.dta) file). I would like to use the code below to convert negative values in my dataset to NA. If a variable has more than 99% NA's the code should drop it.
#mixed data
WVS <-…
Tom
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2 answers
Can compareAndSet fail for all threads?
I'm using AtomicInteger to compare and set synchronization state. Here is it
private final AtomicInteger state = new AtomicInteger(1);
public void tryDo(){
if(state.compareAndSet(1, 2)){
//do some usefule
}
}
The question is if the…
Some Name
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3 answers
AtomicInteger does not get incremented in JUnit tests
I have the following JUnit tests, and can't work out why the second test does not pass, the value of i is 1 in both tests.
public class TestTest {
private AtomicInteger ai = new AtomicInteger(1);
@Test
public void test1() {
int i =…
Bentaye
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0
votes
4 answers
Update AtomicInteger from other thread
I have a class that creates many new objects each on their own thread and I would like to keep a running count across the threads. I wanted to have an AtomicInteger but it's not doing what I expected and instead just gets a smaller version. I'm…
LivingRobot
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2 answers
doubts on AtomicInteger and on printing a bi-dimensional array
I have 2 doubts today.
1) I am trying to print a bi-dimensional array (matrix Nx) and I am using this method:
System.out.println(Arrays.toString(Matr));
the matrix has only int variables.
This is the output, why?
[[I@15db9742, [I@6d06d69c,…
DarkPassenger
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0
votes
2 answers
How to persist an AtomicInteger in hibernate instead of Integer?
I try to persist an object that have an AtomicInteger variable instead of an Integer using the hibernate java framework (I need use the object in a thread safe scenario after save it) but when i try to save my object java…
Martin
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0
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2 answers
AtomicInteger getAndUpdate to zero on Java 6
I am trying to use a counter for detecting number of unique words in a text send over HTTP methods. As I need to ensure concurrency on the value of this counter, I have changed it to AtomicInteger.
In certain cases I would like to get the current…
Kit Ostrihon
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1 answer
Object of class containing AtomicInteger's fails to be converted to JSON using GSON
I am trying to serialize an Object of Class (let's say MyClass)
Here is roughly how MyClass.java looks like:
public class MyClass {
private static final AtomicInteger variableOne = new AtomicInteger();
private static final AtomicInteger…
Nick Div
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0
votes
1 answer
Wait for daemon threads to complete an iteration using an executor service
I have to parallelize an existing background task such that instead of serially consuming 'x' resources, it parallely finishes the job at hand using only 'y' threads (y << x). This task constantly runs in the background and keeps processing some…
user1071840
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0
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1 answer
get() vs intValue() methods in AtomicInteger
AtomicInteger class has 2 methods, get() and intValue() with following definitions.
intValue() definition :
/**
* Returns the value of this {@code AtomicInteger} as an {@code int}.
*/
public int intValue() {
return get();
}
get()…
Sreekanth Karumanaghat
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0
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1 answer
Incrementing int counter with visibility
I have a situation where one thread updates int and another one at some point reads it. So single-reader single-writer.
So far I was using volatile int for that purpose, but since this forces full sync on memory barriers I was thinking about…
ivenhov
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1 answer
Behavoir of Threads with AtomicInteger
The following problem is on a mock exam for the OCP Java SE 7 Programmer II Exam. The solution says the answer is 0, but my colleagues and I are not sure that the answer isn't between -5 and 5 (which is a choice) Could someone clarify this for us?…
Shoikana
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2 answers
AtomicInteger or LongAccumulator
Can someone tell if LongAccumulator could be a better alternative for AtomicInteger in the below example?
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicInteger;
public…
Ashish Pahalzani
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