Code cleanup: extract few code blocks to separate functions + fix comments.

ktor-features/ktor-websockets/jvm/src/io/ktor/websocket/Routing.kt

@@ -125,22 +125,33 @@ private suspend fun WebSocketServerSession.proceedWebSocket(handler: suspend Def
         webSockets.pingInterval?.toMillis() ?: -1L,
         webSockets.timeout.toMillis()
     )
-    session.run {
-        try {
-            toServerSession(call).handler()
-            session.close()
-        } catch (cancelled: CancellationException) {
-            throw cancelled
-        } catch (io: ChannelIOException) {
-            // don't log I/O exceptions
-            throw io
-        } catch (cause: Throwable) {
-            application.log.error("Websocket handler failed", cause)
-            throw cause
-        }
-    }
+    session.handleServerSession(call, handler)
 
-    session.coroutineContext[Job]!!.join()
+    session.joinSession()
+}
+
+private suspend fun CoroutineScope.joinSession() {
+    coroutineContext[Job]!!.join()
+}
+
+@UseExperimental(WebSocketInternalAPI::class)
+private suspend fun DefaultWebSocketSessionImpl.handleServerSession(
+    call: ApplicationCall,
+    handler: suspend DefaultWebSocketServerSession.() -> Unit
+) {
+    try {
+        val serverSession = toServerSession(call)
+        handler(serverSession)
+        close()
+    } catch (cancelled: CancellationException) {
+        throw cancelled
+    } catch (io: ChannelIOException) {
+        // don't log I/O exceptions
+        throw io
+    } catch (cause: Throwable) {
+        call.application.log.error("Websocket handler failed", cause)
+        throw cause
+    }
 }
 
 private class WebSocketProtocolsSelector(

ktor-http/ktor-http-cio/jvm/src/io/ktor/http/cio/websocket/PingPong.kt

@@ -64,7 +64,7 @@ fun CoroutineScope.pinger(
         try {
             while (!isClosedForReceive) {
                 // drop pongs during period delay as they are irrelevant
-                // here timeout is expected so ignore it
+                // here we expect a timeout, so ignore it
                 withTimeoutOrNull(periodMillis) {
                     while (true) {
                         receive() // timeout causes loop to break on receive
@@ -86,7 +86,7 @@ fun CoroutineScope.pinger(
 
                 if (rc == null) {
                     // timeout
-                    // we were unable to send ping or hadn't get valid pong message in time
+                    // we were unable to send the ping or hadn't got a valid pong message in time,
                     // so we are triggering close sequence (if already started then the following close frame could be ignored)
 
                     val closeFrame = Frame.Close(CloseReason(CloseReason.Codes.INTERNAL_ERROR, "Ping timeout"))
@@ -116,12 +116,15 @@ private suspend fun SendChannel<Frame.Ping>.sendPing(
 ) = with(buffer) {
     clear()
     encoder.reset()
-
-    encoder.encode(CharBuffer.wrap(content), this, true).apply {
-        if (this.isError) throwException()
-        else if (this.isOverflow) throwException()
-    }
+    encoder.encodeOrFail(this, content)
     flip()
 
     send(Frame.Ping(this))
 }
+
+private fun CharsetEncoder.encodeOrFail(buffer: ByteBuffer, content: String) {
+    encode(CharBuffer.wrap(content), buffer, true).apply {
+        if (isError) throwException()
+        else if (isOverflow) throwException()
+    }
+}