CustomDispatchers.kt

import java.util.concurrent.Executors
class CustomDispatchers {
    // Single-threaded dispatcher for sequential processing
    val singleThread = Executors.newSingleThreadExecutor().asCoroutineDispatcher()
    
    // Fixed thread pool
    val fixedThreadPool = Executors.newFixedThreadPool(4).asCoroutineDispatcher()
    
    // Cached thread pool (creates threads as needed)
    val cachedThreadPool = Executors.newCachedThreadPool().asCoroutineDispatcher()
    
    fun close() {
        singleThread.close()
        fixedThreadPool.close()
        cachedThreadPool.close()
    }
}
fun main() = runBlocking {
    val dispatchers = CustomDispatchers()
    
    try {
        // Use single-threaded dispatcher for order-sensitive operations
        withContext(dispatchers.singleThread) {
            repeat(5) { i ->
                launch {
                    println("Task $i on ${Thread.currentThread().name}")
                    delay(100)
                }
            }
        }
        
        delay(1000)
        
    } finally {
        dispatchers.close()
    }
}