[net/dns] Retry reading config in DnsConfigServiceWin

net/dns/dns_config_service_win.cc

 // Copyright (c) 2012 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/dns/dns_config_service_win.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 20 matching lines @@
 #include "net/dns/serial_worker.h"
 
 #pragma comment(lib, "iphlpapi.lib")
 
 namespace net {
 
 namespace internal {
 
 namespace {
 
+// Interval between retries to parse config. Used only until parsing succeeds.
+const int kRetryIntervalSeconds = 5;
+
 const wchar_t* const kPrimaryDnsSuffixPath =
     L"SOFTWARE\\Policies\\Microsoft\\System\\DNSClient";
 
 enum HostsParseWinResult {
   HOSTS_PARSE_WIN_OK = 0,
   HOSTS_PARSE_WIN_UNREADABLE_HOSTS_FILE,
   HOSTS_PARSE_WIN_COMPUTER_NAME_FAILED,
   HOSTS_PARSE_WIN_IPHELPER_FAILED,
   HOSTS_PARSE_WIN_BAD_ADDRESS,
   HOSTS_PARSE_WIN_MAX  // Bounding values for enumeration.
@@ skipping 421 matching lines @@
                         base::TimeTicks::Now() - start_time);
   }
 
   virtual void OnWorkFinished() OVERRIDE {
     DCHECK(loop()->BelongsToCurrentThread());
     DCHECK(!IsCancelled());
     if (success_) {
       service_->OnConfigRead(dns_config_);
     } else {
       LOG(WARNING) << "Failed to read DnsConfig.";
+      // Try again in a while in case DnsConfigWatcher missed the signal.
+      MessageLoop::current()->PostDelayedTask(
+          FROM_HERE,
+          base::Bind(&ConfigReader::WorkNow, this),
+          base::TimeDelta::FromSeconds(kRetryIntervalSeconds));
     }
   }
 
   DnsConfigServiceWin* service_;
-  // Written in DoRead(), read in OnReadFinished(). No locking required.
+  // Written in DoWork(), read in OnWorkFinished(). No locking required.
   DnsConfig dns_config_;
   bool success_;
 };
 
 // Reads hosts from HOSTS file and fills in localhost and local computer name if
 // necessary. All work performed on WorkerPool.
 class DnsConfigServiceWin::HostsReader : public SerialWorker {
  public:
   explicit HostsReader(DnsConfigServiceWin* service)
       : path_(GetHostsPath()),
@@ skipping 80 matching lines @@
 
 }  // namespace internal
 
 // static
 scoped_ptr<DnsConfigService> DnsConfigService::CreateSystemService() {
   return scoped_ptr<DnsConfigService>(new internal::DnsConfigServiceWin());
 }
 
 }  // namespace net