Start accepting incoming sockets earlier on Windows, to associate a at AcceptEx error to 'ServerSoc…

runtime/bin/eventhandler_win.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include "bin/eventhandler.h"
 
 #include <winsock2.h>  // NOLINT
@@ skipping 560 matching lines @@
 
 
 ClientSocket* ListenSocket::Accept() {
   ScopedLock lock(this);
   if (accepted_head_ == NULL) return NULL;
   ClientSocket* result = accepted_head_;
   accepted_head_ = accepted_head_->next();
   if (accepted_head_ == NULL) accepted_tail_ = NULL;
   result->set_next(NULL);
   if (!IsClosing()) {
-    while (pending_accept_count() < 5) {
-      if (!IssueAccept()) {
-        HandleError(this);
-      }
+    if (!IssueAccept()) {
+      HandleError(this);
     }
   }
   return result;
 }
 
 
 void ListenSocket::EnsureInitialized(
     EventHandlerImplementation* event_handler) {
   ScopedLock lock(this);
   if (AcceptEx_ == NULL) {
@@ skipping 438 matching lines @@
       Handle::ScopedLock lock(listen_socket);
 
       // If incoming connections are requested make sure to post already
       // accepted connections.
       if ((msg->data & (1 << kInEvent)) != 0) {
         if (listen_socket->CanAccept()) {
           int event_mask = (1 << kInEvent);
           handle->set_mask(handle->mask() & ~event_mask);
           DartUtils::PostInt32(handle->port(), event_mask);
         }
-        // Always keep 5 outstanding accepts going, to enhance performance.
-        while (listen_socket->pending_accept_count() < 5) {
-          bool accept_success = listen_socket->IssueAccept();
-          if (!accept_success) {
-            HandleError(listen_socket);
-            break;
-          }
-        }
       }
     } else {
       handle->EnsureInitialized(this);
 
       Handle::ScopedLock lock(handle);
 
       // Only set mask if we turned on kInEvent or kOutEvent.
       if ((msg->data & ((1 << kInEvent) | (1 << kOutEvent))) != 0) {
         handle->SetPortAndMask(msg->dart_port, msg->data);
       }
@@ skipping 311 matching lines @@
 
 
 void EventHandlerImplementation::Shutdown() {
   SendData(kShutdownId, 0, 0);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)