AbstractCoroutine: onCancellation shall be invoked before installed

cancellation handler

Author: elizarov

common/kotlinx-coroutines-core-common/src/test/kotlin/kotlinx/coroutines/experimental/AbstractCoroutineTest.kt

@@ -41,15 +41,19 @@ class AbstractCoroutineTest : TestBase() {
                 expectUnreached()
             }
         }
-        coroutine.invokeOnCompletion {
+        coroutine.invokeOnCompletion(onCancelling = true) {
             assertTrue(it == null)
             expect(7)
         }
+        coroutine.invokeOnCompletion {
+            assertTrue(it == null)
+            expect(8)
+        }
         expect(2)
         coroutine.start()
         expect(4)
         coroutine.resume("OK")
-        finish(8)
+        finish(9)
     }
 
     @Test
@@ -71,20 +75,24 @@ class AbstractCoroutineTest : TestBase() {
 
             override fun onCompletedExceptionally(exception: Throwable) {
                 assertTrue(exception is TestException1)
-                expect(7)
+                expect(8)
             }
         }
+        coroutine.invokeOnCompletion(onCancelling = true) {
+            assertTrue(it is TestException0)
+            expect(6)
+        }
         coroutine.invokeOnCompletion {
             assertTrue(it is TestException1)
-            expect(8)
+            expect(9)
         }
         expect(2)
         coroutine.start()
         expect(4)
         coroutine.cancel(TestException0())
-        expect(6)
+        expect(7)
         coroutine.resumeWithException(TestException1())
-        finish(9)
+        finish(10)
     }
 
     private class TestException0 : Throwable()

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

@@ -1012,8 +1012,8 @@ internal actual open class JobSupport actual constructor(active: Boolean) : Job,
     private fun tryMakeCancelling(expect: Incomplete, list: NodeList, cause: Throwable?): Boolean {
         val cancelled = Cancelled(this, cause)
         if (!_state.compareAndSet(expect, Finishing(list, cancelled, false))) return false
-        notifyCancellation(list, cause)
         onCancellationInternal(cancelled)
+        notifyCancellation(list, cause)
         return true
     }
 

js/kotlinx-coroutines-core-js/src/main/kotlin/kotlinx/coroutines/experimental/Job.kt

@@ -724,8 +724,8 @@ internal actual open class JobSupport actual constructor(active: Boolean) : Job
     private fun makeCancellingList(list: NodeList, cause: Throwable?) {
         val cancelled = Cancelled(this, cause)
         state = Finishing(list, cancelled, false)
-        notifyCancellation(list, cause)
         onCancellationInternal(cancelled)
+        notifyCancellation(list, cause)
     }
 
     private fun makeCompletingOnCancel(cause: Throwable?): Boolean =