Nicer toString implementations for CommonPool & Unconfined dispatchers

Author: elizarov

kotlinx-coroutines-core/src/main/kotlin/kotlinx/coroutines/experimental/CommonPool.kt

@@ -82,4 +82,6 @@ object CommonPool : CoroutineDispatcher() {
         }
         usePrivatePool = false
     }
+
+    override fun toString(): String = "CommonPool"
 }

kotlinx-coroutines-core/src/main/kotlin/kotlinx/coroutines/experimental/CoroutineContext.kt

@@ -48,6 +48,7 @@ internal fun resetCoroutineId() {
 public object Unconfined : CoroutineDispatcher() {
     override fun isDispatchNeeded(context: CoroutineContext): Boolean = false
     override fun dispatch(context: CoroutineContext, block: Runnable) { throw UnsupportedOperationException() }
+    override fun toString(): String = "Unconfined"
 }
 
 /**

kotlinx-coroutines-core/src/main/kotlin/kotlinx/coroutines/experimental/CoroutineDispatcher.kt

@@ -91,6 +91,11 @@ public abstract class CoroutineDispatcher :
             "The dispatcher to the right of `+` just replaces the dispatcher the left of `+`.",
             level = DeprecationLevel.ERROR)
     public operator fun plus(other: CoroutineDispatcher) = other
+
+    // for nicer debugging
+    override fun toString(): String =
+        "${this::class.java.simpleName}@${Integer.toHexString(System.identityHashCode(this))}"
+
 }
 
 internal class DispatchedContinuation<in T>(

kotlinx-coroutines-core/src/main/kotlin/kotlinx/coroutines/experimental/EventLoop.kt

@@ -128,8 +128,6 @@ internal class EventLoopImpl(
         }
     }
 
-    override fun toString(): String = "EventLoopImpl@${Integer.toHexString(System.identityHashCode(this))}"
-
     private fun scheduleQueued(queuedTask: QueuedTask): Boolean {
         if (parentJob == null) {
             queue.addLast(queuedTask)