dgram: generalized send queue to handle close

If the udp socket is not ready and we are accumulating messages to send, it needs to delay closing the socket when all messages are flushed. Fixes: #7061 PR-URL: #7066 Reviewed-By: Anna Henningsen <anna@addaleax.net>
nodejs · mcollina · May 30, 2016 · Nov 19, 2016 · 0d7bf1d72308603445a6de340e65fa2af3701682
commit 0d7bf1d72308603445a6de340e65fa2af3701682
diff --git a/lib/dgram.js b/lib/dgram.js
@@ -243,6 +243,32 @@ Socket.prototype.sendto = function(buffer,
 };
 
 
+function enqueue(self, toEnqueue) {
+  // If the send queue hasn't been initialized yet, do it, and install an
+  // event handler that flushes the send queue after binding is done.
+  if (!self._queue) {
+    self._queue = [];
+    self.once('listening', clearQueue);
+  }
+  self._queue.push(toEnqueue);
+  return;
+}
+
+
+function clearQueue() {
+  const queue = this._queue;
+  this._queue = undefined;
+
+  // Flush the send queue.
+  for (var i = 0; i < queue.length; i++)
+    queue[i]();
+}
+
+
+// valid combinations
+// send(buffer, offset, length, port, address, callback)
+// send(buffer, offset, length, port, address)
+// send(buffer, offset, length, port)
 Socket.prototype.send = function(buffer,
                                  offset,
                                  length,
@@ -290,18 +316,13 @@ Socket.prototype.send = function(buffer,
   // If the socket hasn't been bound yet, push the outbound packet onto the
   // send queue and send after binding is complete.
   if (self._bindState != BIND_STATE_BOUND) {
-    // If the send queue hasn't been initialized yet, do it, and install an
-    // event handler that flushes the send queue after binding is done.
-    if (!self._sendQueue) {
-      self._sendQueue = [];
-      self.once('listening', function() {
-        // Flush the send queue.
-        for (var i = 0; i < self._sendQueue.length; i++)
-          self.send.apply(self, self._sendQueue[i]);
-        self._sendQueue = undefined;
-      });
-    }
-    self._sendQueue.push([buffer, offset, length, port, address, callback]);
+    enqueue(self, self.send.bind(self,
+                                 buffer,
+                                 offset,
+                                 length,
+                                 port,
+                                 address,
+                                 callback));
     return;
   }
 
@@ -347,10 +368,15 @@ function afterSend(err) {
   this.callback(err, this.length);
 }
 
-
 Socket.prototype.close = function(callback) {
   if (typeof callback === 'function')
     this.on('close', callback);
+
+  if (this._queue) {
+    this._queue.push(this.close.bind(this));
+    return this;
+  }
+
   this._healthCheck();
   this._stopReceiving();
   this._handle.close();

diff --git a/test/parallel/test-dgram-close-in-listening.js b/test/parallel/test-dgram-close-in-listening.js
@@ -0,0 +1,18 @@
+'use strict';
+// Ensure that if a dgram socket is closed before the sendQueue is drained
+// will not crash
+
+const common = require('../common');
+const dgram = require('dgram');
+
+const buf = Buffer.alloc(1024, 42);
+
+const socket = dgram.createSocket('udp4');
+
+socket.on('listening', function() {
+  socket.close();
+});
+
+// adds a listener to 'listening' to send the data when
+// the socket is available
+socket.send(buf, 0, buf.length, common.PORT, 'localhost');