How to Pass Different Values to Each Thread in ExecutorService?

Описание: Learn how to efficiently pass distinct values to each thread using ExecutorService in Java. This guide breaks down the solution step-by-step.
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How to Pass Different Values to Each Thread in ExecutorService?

When working with multithreading in Java, you might come across a situation where you need to pass different values to each thread. For instance, let’s say you have an array of integers and you want to pass elements from this array to individual threads for processing. This guide will detail how to achieve that using ExecutorService in a structured and easy-to-understand manner.

Understanding the Problem

Consider you have an array named num_array filled with integers, say from 0 to 30. With a multithreading function, your goal is to ensure that:

thread 1 receives the value from num_array[0]

thread 2 gets the value from num_array[1]

and so on up to thread 25 which would receive num_array[24]

Here is the simplified version of your setup:

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However, attempting to create a Runnable directly without a loop will not work as intended for the distinct values. Now, let’s dive into the solution.

Step-by-Step Solution

Step 1: Initialize the ExecutorService

You already have the line to create an instance of ExecutorService with a fixed thread pool of 25 threads, which is great. This will be the pool from which threads will be drawn.

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Step 2: Loop through the Array

You need to iterate over the num_array, and for each element, create a new Runnable that encapsulates the behavior for the thread. Here is how that can be done:

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Important Considerations

Thread Order: Remember that the order in which threads will start and finish is dependent on various factors like thread scheduler and the system load. Do not assume that the order of elements corresponds to the order in which threads are executed.

Runnable Implementation: Make sure that your FunctToBeMultithreadded class correctly implements Runnable and utilizes the passed integer as needed.

Step 3: Shutdown the Executor

Once all the tasks have been submitted, it’s crucial to shut down the executor to free the resources.

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Complete Example

Here’s what the complete multi-threading function might look like with all the components included:

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Conclusion

Passing different values to each thread using ExecutorService can be done easily by looping through your array and creating a new Runnable for each element. This method allows each thread to operate independently with its own distinct value. With a solid understanding of ExecutorService and Runnable, you can leverage the power of Java multithreading effectively!

Now you’re equipped with the knowledge to handle multithreading in Java and ensure that each thread processes a separate piece of data from your array. Happy coding!