refactor(server): do not permit commands when server is closed

Author: mbroadst

lib/core/sdam/server.js

@@ -240,6 +240,11 @@ class Server extends EventEmitter {
       (callback = options), (options = {}), (options = options || {});
     }
 
+    if (this.s.state === STATE_CLOSING || this.s.state === STATE_CLOSED) {
+      callback(new MongoError('server is closed'));
+      return;
+    }
+
     const error = basicReadValidations(this, options);
     if (error) {
       return callback(error, null);
@@ -289,6 +294,11 @@ class Server extends EventEmitter {
    * @param {function} callback
    */
   query(ns, cmd, cursorState, options, callback) {
+    if (this.s.state === STATE_CLOSING || this.s.state === STATE_CLOSED) {
+      callback(new MongoError('server is closed'));
+      return;
+    }
+
     wireProtocol.query(this, ns, cmd, cursorState, options, (err, result) => {
       if (err) {
         if (options.session && err instanceof MongoNetworkError) {
@@ -313,6 +323,11 @@ class Server extends EventEmitter {
    * @param {function} callback
    */
   getMore(ns, cursorState, batchSize, options, callback) {
+    if (this.s.state === STATE_CLOSING || this.s.state === STATE_CLOSED) {
+      callback(new MongoError('server is closed'));
+      return;
+    }
+
     wireProtocol.getMore(this, ns, cursorState, batchSize, options, (err, result) => {
       if (err) {
         if (options.session && err instanceof MongoNetworkError) {
@@ -336,6 +351,14 @@ class Server extends EventEmitter {
    * @param {function} callback
    */
   killCursors(ns, cursorState, callback) {
+    if (this.s.state === STATE_CLOSING || this.s.state === STATE_CLOSED) {
+      if (typeof callback === 'function') {
+        callback(new MongoError('server is closed'));
+      }
+
+      return;
+    }
+
     wireProtocol.killCursors(this, ns, cursorState, (err, result) => {
       if (err && isSDAMUnrecoverableError(err, this)) {
         this.emit('error', err);
@@ -438,6 +461,11 @@ function executeWriteOperation(args, options, callback) {
   const ns = args.ns;
   const ops = Array.isArray(args.ops) ? args.ops : [args.ops];
 
+  if (server.s.state === STATE_CLOSING || server.s.state === STATE_CLOSED) {
+    callback(new MongoError('server is closed'));
+    return;
+  }
+
   const error = basicWriteValidations(server, options);
   if (error) {
     callback(error, null);