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Questions tagged [callable]

A task that returns a result and may throw an exception.

The Callable interface is similar to Runnable, in that both are designed for classes whose instances are potentially executed by another thread. A Runnable, however, does not return a result and cannot throw a checked exception.

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Use php callable to call constructor

I am trying to call a class' constructor through a callable, so I had the following code: $callable = array('Foo', '__construct'); However calling this will throw the following error: Fatal error: Non-static method Foo::__construct() cannot be…
Choraimy
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How to cancel (or just interrupt) a scala.concurrent.Future?

I have a Java library that performs long running blocking operations. The library is designed to respond to user cancellation requests. The library integration point is the Callable interface. I need to integrate this library into my application…
axiopisty
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Android Callable

How to implement Callable to return boolean and do something ? I need use external Thread to connect to FTP server, I can't do this in main activity and I need return value to know it's connected or not; [MainActivity] public class doSomething…
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Do callable executes sequentially?

Whenever i run my program implementing callable, i get the output in a sequential form. Like, here is my program : package com.handson; import java.util.concurrent.ArrayBlockingQueue; import java.util.concurrent.BlockingQueue; import…
Prateek
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Why am I getting a NullPointerException when fetching values from Futures?

I'm using and ExecutorService to concurrently run some Callables. Here's a simplified version of my code: ArrayList objResults = new ArrayList(); ExecutorService esrExecutor =…
Mridang Agarwalla
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Do spurious wakeups affect Future.get()?

Is Future.get( timeout, unit ) susceptible to the same type of spurious wakeup as documented for Object.wait() and Condition.await() in Javadoc? someType result; Future future = executor.submit( new callableTask() ); result = future.get(…
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How to get a string value from a thread at fixed intervals while able to pause/resume?

I have made a small swing application for my personal use. This app connects to internet, retrieves a text file, displays its contents in a jTextArea and saves the text file locally (in my hardisk). So far so good. Now I want to receive this text…
mzeeshan
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Using callable to pass two parameters and returning an array of parameters

I have to pass two strings to a thread, which will return an array containing both of them, and I must use callable. Here's what I have so far: public class toArray implements Callable { private String string1 string2; public toArray…
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Multithreaded file processing and reporting

I have an application that processes data stored in a number of files from an input directory and then produces some output depending on that data. So far, the application works in a sequential basis, i.e. it launches a "manager" thread that Reads…
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How to send a function to a remote Pyro object

I am trying to set up some code using Pyro to process python code functions on a remote host and get results back. After starting the name server, i would execute this code on the remote host (actually still on localhost): import Pyro4 class…
Davide
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Java: ExecutorService with Callables: Timeout: future.get() leads to direct break of program

I use the ExecutorService in Java and I noticed a behaviour I dont understand. I use Callable and when I invoke my threads (classes that implement Callable) I set a timeout. Then I wait for the result with future.get() and after I wanted to check…
nano7
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Polymorphism with callables in Python

I have an interface class called iResource, and a number of subclasses, each of which implement the "request" method. The request functions use socket I/O to other machines, so it makes sense to run them asynchronously, so those other machines can…
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Why the exception is not being thrown?

I have this simple piece of code: @Override public Object call() throws Exception { try (Connection conn = ConnectionPool.getConnection()) { pageDAO = new PageDAO(conn); linkDAO = new LinkDAO(conn); loopInsertion(); …
Renato Dinhani
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How to interface this DFS code with a Boost Graph DFS?

Background I have defined formatting operations on trees that work pretty well when they are used a pre/in/post order operators with the following structure and DFS definition (it works also on k-ary trees): struct Node { Node *parent = nullptr; …
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chaining callables in C++

I come from the python world where I could define a chain of operations and call them in a for loop: class AddOne: def __call__(self, x, **common_kwargs): return x+1 class Stringify: def __call__(self, x, **common_kwargs): …
Jav
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