javaAsync race conditionMedium

Thread hangs unexpectedly after external service call

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BugFind the bug and fix the code

What it should do

Fetch data from an external service and return the result. Example: fetchDataFromService() -> data

What happens instead

The program hangs indefinitely after calling fetchDataFromService.

public class ServiceFetcher {
    public static String fetchDataFromService() {
        try {
            Thread.sleep(100);
            return "Data from service";
        } catch (InterruptedException e) {
            // Swallowed interrupt
            return null;
        }
    }
}

Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).

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This bug belongs to the async and race conditions pattern

A missing await, unbuffered channel deadlocks, ConcurrentModificationException, and data races under load.

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public class ServiceFetcher { public static String fetchDataFromService() { try { Thread.sleep(100); return "Data from service"; } catch (InterruptedException e) { // Swallowed interrupt return null; } } }

Thread hangs unexpectedly after external service call

What it should do

What happens instead

More async and race conditions to practise

Thread hangs unexpectedly after external service call

What it should do

What happens instead

More async and race conditions to practise