Avoid doing concurrent DNS resolves of the same hostname

net/base/address_list_unittest.cc

+// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/base/address_list.h"
+
+#if defined(OS_WIN)
+#include <ws2tcpip.h>
+#include <wspiapi.h>  // Needed for Win2k compat.
+#elif defined(OS_POSIX)
+#include <netdb.h>
+#include <sys/socket.h>
+#endif
+
+#include "base/string_util.h"
+#include "net/base/net_util.h"
+#if defined(OS_WIN)
+#include "net/base/winsock_init.h"
+#endif
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+// Use getaddrinfo() to allocate an addrinfo structure.
+void CreateAddressList(net::AddressList* addrlist, int port) {
+#if defined(OS_WIN)
+  net::EnsureWinsockInit();
+#endif
+  std::string portstr = IntToString(port);
+
+  struct addrinfo* result = NULL;
+  struct addrinfo hints = {0};
+  hints.ai_family = AF_UNSPEC;
+  hints.ai_flags = AI_NUMERICHOST;
+  hints.ai_socktype = SOCK_STREAM;
+
+  int err = getaddrinfo("192.168.1.1", portstr.c_str(), &hints, &result);
+  EXPECT_EQ(0, err);
+  addrlist->Adopt(result);
+}
+
+TEST(AddressListTest, GetPort) {
+  net::AddressList addrlist;
+  CreateAddressList(&addrlist, 81);
+  EXPECT_EQ(81, addrlist.GetPort());
+
+  addrlist.SetPort(83);
+  EXPECT_EQ(83, addrlist.GetPort());
+}
+
+TEST(AddressListTest, Assignment) {
+  net::AddressList addrlist1;
+  CreateAddressList(&addrlist1, 85);
+  EXPECT_EQ(85, addrlist1.GetPort());
+
+  // Should reference the same data as addrlist1 -- so when we change addrlist1
+  // both are changed.
+  net::AddressList addrlist2 = addrlist1;
+  EXPECT_EQ(85, addrlist2.GetPort());
+
+  addrlist1.SetPort(80);
+  EXPECT_EQ(80, addrlist1.GetPort());
+  EXPECT_EQ(80, addrlist2.GetPort());
+}
+
+TEST(AddressListTest, Copy) {
+  net::AddressList addrlist1;
+  CreateAddressList(&addrlist1, 85);
+  EXPECT_EQ(85, addrlist1.GetPort());
+
+  net::AddressList addrlist2;
+  addrlist2.Copy(addrlist1.head());
+
+  // addrlist1 is the same as addrlist2 at this point.
+  EXPECT_EQ(85, addrlist1.GetPort());
+  EXPECT_EQ(85, addrlist2.GetPort());
+
+  // Changes to addrlist1 are not reflected in addrlist2.
+  addrlist1.SetPort(70);
+  addrlist2.SetPort(90);
+
+  EXPECT_EQ(70, addrlist1.GetPort());
+  EXPECT_EQ(90, addrlist2.GetPort());
+}
+
+}  // namespace