CompletionService.take().isDone() always true?

Posted by jfager on Stack Overflow See other posts from Stack Overflow or by jfager
Published on 2010-04-09T19:29:19Z Indexed on 2010/04/09 19:33 UTC
Read the original article Hit count: 238

Filed under:

java

|

concurrency

|

futures

Is it safe to assume that

java.util.concurrent.CompletionService.take().isDone()

will always return true? If so, why does take() return a Future, rather than the value directly? If not, what does "completed task" as used in the documentation mean?

© Stack Overflow or respective owner

Related posts about java

Tomcat 6: Access Control Exception?

as seen on Server Fault - Search for 'Server Fault'
I'm trying to setup a tomcat6 server, and I'm trying to match another setup someone else established. However, my deployment (default Ubuntu install) uses a policy.d/ directory structure, and the established server just uses a catalina.policy file. I've tried setting every entry in policy.d to match… >>> More
Problem in creation MDB Queue connection at Jboss StartUp

as seen on Stack Overflow - Search for 'Stack Overflow'
I am not able to create a Queue connection in JBOSS4.2.3GA Version & Java1.5, as I am using MDB as per the below details. I am putting this MDB in a jar file(named utsJar.jar) and copied it in deploy folder of JBOSS, In the test env. this MDB works well but in another env. [ env settings and… >>> More
failing to establish connection between Postgres db and gwt

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am using Postgres and gwt 2.0 for one of my applications. I am facing problem connecting to the database. When I try to connect it gives "ClassNotFoundException". Here is what I get when I try to connect to database: java.lang.ClassNotFoundException: org.postgresql.Driver at java.net… >>> More
failing to establish connection between postgre db and gwt

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, For i am using postgre and gwt 2.0 for one of my applications. I am facing problem connecting to the database. When i try to connect it gives "ClassNotFoundException". Here is what i get when i try to connect to database: java.lang.ClassNotFoundException: org.postgresql.Driver at java.net… >>> More
Migration and deployement problems JBoss 4.2.2.GA to JBoss 6.0.0.M2

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I'm trying to migrate an application running on JBoss 4.2.2.GA to JBoss 6.0.0.M2 I give you some log to explain my problem : boot.log : 2010-03-16 09:59:29,406 ERROR [org.jboss.system.server.profileservice.ProfileServiceBootstrap] (Thread-2) Failed to load profile: Summary of incomplete deployments… >>> More

Related posts about concurrency

SQL SERVER – Concurrency Basics – Guest Post by Vinod Kumar

as seen on SQL Authority - Search for 'SQL Authority'
This guest post is by Vinod Kumar. Vinod Kumar has worked with SQL Server extensively since joining the industry over a decade ago. Working on various versions from SQL Server 7.0, Oracle 7.3 and other database technologies – he now works with the Microsoft Technology Center (MTC) as a Technology… >>> More
Http requests / concurrency?

as seen on Stack Overflow - Search for 'Stack Overflow'
Say a website on my localhost takes about 3 seconds to do each request. This is fine, and as expected (as it is doing some fancy networking behind the scenes). However, if i open the same url in tabs (in firefox), then reload them all at the same time, it appears to load each page sequentially rather… >>> More
Mnesia: A Distributed DBMS Rooted in Concurrency

as seen on Internet.com - Search for 'Internet.com'
Find out what makes Mnesia, the Erlang-based database management system, perfect for distribution across a network of computers. >>> More
C# concurrency vs Java concurrency, which is neatly designed? which is better?

as seen on Stack Overflow - Search for 'Stack Overflow'
I am hard core fan for Doug Lee and his concurrency framework. I have also (from twitter) came across a comment from Joshua Bloch that java concurrency is one of the best framework (guess that he compared to .Net). But some of you worked in both Java Concurrency and .NET concurrency. What is your… >>> More
Queued Loadtest to remove Concurrency issues using Shared Data Service in OpenScript

as seen on Oracle Blogs - Search for 'Oracle Blogs'
Queued Processing to remove Concurrency issues in Loadtest ScriptsSome scripts act on information returned by the server, e.g. act on first item in the returned list of pending tasks/actions. This may lead to concurrency issues if the virtual users simulated in a load test scenario are not synchronized… >>> More