http2: use _final instead of on('finish')

PR-URL: #18609
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>

lib/internal/http2/core.js

@@ -1412,18 +1412,6 @@ function afterDoStreamWrite(status, handle, req) {
   req.handle = undefined;
 }
 
-function onHandleFinish() {
-  const handle = this[kHandle];
-  if (this[kID] === undefined) {
-    this.once('ready', onHandleFinish);
-  } else if (handle !== undefined) {
-    const req = new ShutdownWrap();
-    req.oncomplete = () => {};
-    req.handle = handle;
-    handle.shutdown(req);
-  }
-}
-
 function streamOnResume() {
   if (!this.destroyed && !this.pending)
     this[kHandle].readStart();
@@ -1444,6 +1432,13 @@ function abort(stream) {
   }
 }
 
+function afterShutdown() {
+  this.callback();
+  const stream = this.handle[kOwner];
+  if (stream)
+    stream[kMaybeDestroy]();
+}
+
 // An Http2Stream is a Duplex stream that is backed by a
 // node::http2::Http2Stream handle implementing StreamBase.
 class Http2Stream extends Duplex {
@@ -1466,7 +1461,6 @@ class Http2Stream extends Duplex {
       writeQueueSize: 0
     };
 
-    this.once('finish', onHandleFinish);
     this.on('resume', streamOnResume);
     this.on('pause', streamOnPause);
   }
@@ -1672,6 +1666,23 @@ class Http2Stream extends Duplex {
     trackWriteState(this, req.bytes);
   }
 
+  _final(cb) {
+    const handle = this[kHandle];
+    if (this[kID] === undefined) {
+      this.once('ready', () => this._final(cb));
+    } else if (handle !== undefined) {
+      debug(`Http2Stream ${this[kID]} [Http2Session ` +
+            `${sessionName(this[kSession][kType])}]: _final shutting down`);
+      const req = new ShutdownWrap();
+      req.oncomplete = afterShutdown;
+      req.callback = cb;
+      req.handle = handle;
+      handle.shutdown(req);
+    } else {
+      cb();
+    }
+  }
+
   _read(nread) {
     if (this.destroyed) {
       this.push(null);