My situation I’m trying to craft a functionality which would execute n (where n >=0) requests to a given endpoint, but I do understand that sometimes that endpoint might not respond due to 500 error or other issue, so I want to repeat my requests to an endpoint (with a small interval in between [not …
Tag: java.util.concurrent
Java concurrent programming – endless loop
I am reading the book Introducing Play Framework: Java Web Application Development (ISBN 978-1-4842-5645-9) and there is this example on Callable: My question is, if the computation of the Future throws and exception, will the while loop run forever? In my opinion, yes, it will loop forever. First, if the Fut…
Running a compiler in parallel with java.utils.concurrent
I am making a compiler for a language in Java and I want it to compile many files in parallel. I have my class Compiler.java that has the constructor Compiler(String fileName) and the method compile() So to compile a single file in my main all I do is : What I want to do is for a list of files
What does “Aren’t allocating the things put into queues” mean?
I’m reading this: https://concurrency.markmail.org/search/?q=ArrayBlockingQueue+LinkedBlockingQueue#query:ArrayBlockingQueue%20LinkedBlockingQueue%20from%3A%22Doug%20Lea%22+page:1+mid:sgx3amdfga7esqul+state:results In which Doug Lea says: Usually, when you are putting something into a queue, you will ha…
Why does calling CompletableFuture::cancel cause an immediate CancellationException
I am trying to call cancel on CompletableFuture. It seems from the docs: If not already completed, completes this CompletableFuture with a CancellationException. Dependent CompletableFutures that have not already completed will also complete exceptionally, with a CompletionException caused by this Cancellatio…
Iterating and removing elements from ConcurrentLinkedQueue
I have defined a ConcurrentLinkedQueue and looping over it like : Now if I delete carTask from the queue. which is an element in the queue while we are doing a forEach will that lead to any issue ? One alternative I think of is put the elements to be deleted in a separate List and once the forEach is
CompletableFuture from Callable?
Today I experimented with the “new” CompletableFuture from Java 8 and found myself confused when I didn’t find a runAsync(Callable) method. I can do it myself like shown below, but why is this (to me very obvious and useful utility method) missing? Am I missing something? Answer You are supp…
future.cancel does not work
I have a nice and compact code, which does not work as I expected. The output is : Timeout true END Question: Why does not terminate the future.cancel(true) method the called Runnable? After the program wrote the “END” to the output, the “r” Runnable is still running. Answer The proble…
Usecase of using AtomicStampedReference & AtomicMarkableReference
I am looking for a example of AtomicStampedReference and/or AtomicMarkableReference, that could help me understand these classes and their functions. I am not able to get any quality examples over the web. I can think of using these in garbage collection, but a quality example will help me understand these be…