From cb9f96126f2c8f720498a2488af991569a7655a0 Mon Sep 17 00:00:00 2001
From: Michael Lumish <mlumish@google.com>
Date: Mon, 8 Jun 2020 14:44:14 -0700
Subject: [PATCH] grpc-js: server: cull closed sessions from list, check for
 closed in tryShutdown

---
 packages/grpc-js/src/server.ts | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/packages/grpc-js/src/server.ts b/packages/grpc-js/src/server.ts
index a6edee3b..22fb3c72 100644
--- a/packages/grpc-js/src/server.ts
+++ b/packages/grpc-js/src/server.ts
@@ -500,10 +500,12 @@ export class Server {
       }
     }
 
-    // If any sessions are active, close them gracefully.
     pendingChecks += this.sessions.size;
     this.sessions.forEach((session) => {
-      session.close(maybeCallback);
+      if (!session.closed) {
+        pendingChecks += 1;
+        session.close(maybeCallback);
+      }
     });
     if (pendingChecks === 0) {
       callback();
@@ -608,6 +610,10 @@ export class Server {
       }
 
       this.sessions.add(session);
+
+      session.on('close', () => {
+        this.sessions.delete(session);
+      });
     });
   }
 }