Problem Statement
Explain structured concurrency in Kotlin Coroutines and how it helps manage coroutine lifecycle.
Explanation
Structured concurrency means coroutines are organized in hierarchies where child coroutines are bound to parent scopes, ensuring children are cancelled when parents are cancelled, preventing coroutine leaks. A parent coroutine waits for all children to complete before completing itself, providing automatic cleanup and cancellation propagation.
CoroutineScope defines boundaries for coroutine execution, and launching coroutines within a scope makes them children of that scope. When you cancel a scope or it completes, all child coroutines are automatically cancelled, preventing orphaned background work.
Structured concurrency eliminates manual lifecycle management required with threads or callbacks, automatically handles cancellation propagation, and makes concurrent code easier to reason about. Use viewModelScope in Android or custom scopes with proper lifecycle to ensure coroutines don't leak.
This structure prevents common bugs like continuing background work after the UI is destroyed, ensures proper cleanup, and makes concurrent code more predictable and maintainable through clear parent-child relationships.
