Avoid Explicit Thread Management

ID

java.avoid_explicit_thread_management

Severity

low

Resource

Api

Language

Java

Tags

CWE:383, NIST.SP.800-53

Description

Improper direct management of threads within a J2EE application.

Rationale

Explicitly managing threads within Java applications can result in a number of issues, including thread leaks, inability to scale effectively, and difficulties in handling exceptions.

Direct thread management requires developers to deal with low-level operations, which increases the complexity and risk of errors.

Instead, using the Java Executor framework or similar constructs offers automatic thread pool management and a higher abstraction level for thread handling.

Consider the following example of explicit thread management in Java:

public class ThreadExample {

    public static void main(String[] args) {
        for (int i = 0; i < 5; i++) {
            Thread thread = new Thread(new Task());
            thread.start();
        }
    }
}

class Task implements Runnable {
    @Override
    public void run() {
        System.out.println("Task executed by " + Thread.currentThread().getName());
    }
}

In this code, threads are manually instantiated and started, which may lead to problems such as resource exhaustion and inefficiencies due to direct thread management.

Remediation

To remediate the risks associated with explicit thread management, Java applications should employ the Executor framework, such as ExecutorService, for handling concurrency.

This approach helps ensure better resource management and scalability, with less manual intervention needed for thread lifecycle management.

Here’s how to refactor the previous example using ExecutorService:

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class ExecutorExample {

    public static void main(String[] args) {
        ExecutorService executor = Executors.newFixedThreadPool(5);

        for (int i = 0; i < 5; i++) {
            executor.submit(new Task());
        }

        // Shut down the executor
        executor.shutdown();
    }
}

class Task implements Runnable {
    @Override
    public void run() {
        System.out.println("Task executed by " + Thread.currentThread().getName());
    }
}

By using ExecutorService, the application can efficiently manage thread resources, automatically provide pooling, and facilitate better control over thread execution, enhancing both performance and reliability.

References