Restore TCO in BufferedChannel (#3627)

qwwdfsad · web-flow · commit 36065e66d08d · 2023-02-14T18:02:44.000+03:00
diff --git a/kotlinx-coroutines-core/common/src/channels/BufferedChannel.kt b/kotlinx-coroutines-core/common/src/channels/BufferedChannel.kt
@@ -130,7 +130,8 @@ internal open class BufferedChannel<E>(
             onNoWaiterSuspend = { segm, i, elem, s -> sendOnNoWaiterSuspend(segm, i, elem, s) }
         )
 
-    private suspend fun onClosedSend(element: E): Nothing = suspendCancellableCoroutine { continuation ->
+    // NB: return type could've been Nothing, but it breaks TCO
+    private suspend fun onClosedSend(element: E): Unit = suspendCancellableCoroutine { continuation ->
         onUndeliveredElement?.callUndeliveredElementCatchingException(element)?.let {
             // If it crashes, add send exception as suppressed for better diagnostics
             it.addSuppressed(sendException)

Original file line number	Diff line number	Diff line change
`@@ -130,7 +130,8 @@ internal open class BufferedChannel<E>(`
`130`	`130`	`onNoWaiterSuspend = { segm, i, elem, s -> sendOnNoWaiterSuspend(segm, i, elem, s) }`
`131`	`131`	`)`
`132`	`132`
`133`		`- private suspend fun onClosedSend(element: E): Nothing = suspendCancellableCoroutine { continuation ->`
	`133`	`+ // NB: return type could've been Nothing, but it breaks TCO`
	`134`	`+ private suspend fun onClosedSend(element: E): Unit = suspendCancellableCoroutine { continuation ->`
`134`	`135`	`onUndeliveredElement?.callUndeliveredElementCatchingException(element)?.let {`
`135`	`136`	`// If it crashes, add send exception as suppressed for better diagnostics`
`136`	`137`	`it.addSuppressed(sendException)`