Delete SignalThread class.

webrtc/base/nethelpers.h

 /*
  *  Copyright 2008 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_BASE_NETHELPERS_H_
 #define WEBRTC_BASE_NETHELPERS_H_
 
 #if defined(WEBRTC_POSIX)
 #include <netdb.h>
 #include <stddef.h>
 #elif WEBRTC_WIN
 #include <winsock2.h>  // NOLINT
 #endif
 
 #include <list>
 
 #include "webrtc/base/asyncresolverinterface.h"
-#include "webrtc/base/signalthread.h"
+#include "webrtc/base/platform_thread.h"
 #include "webrtc/base/sigslot.h"
 #include "webrtc/base/socketaddress.h"
 
 namespace rtc {
 
-class AsyncResolverTest;
+class Thread;
 
 // AsyncResolver will perform async DNS resolution, signaling the result on
 // the SignalDone from AsyncResolverInterface when the operation completes.

[Taylor Brandstetter, 2017/06/05 22:33:25]

nit: Could you add a comment saying that SignalDone will be fired from the same
thread on which the AsyncResolver was constructed?

[nisse-webrtc, 2017/06/07 07:17:31]

Done. But maybe that comment belongs with the AsyncResolverInterface class
(which doesn't mention threads at all)?

[Taylor Brandstetter, 2017/06/09 02:50:13]

The comment applies to this class's constructor specifically, so this seems like
the right place.

-class AsyncResolver : public SignalThread, public AsyncResolverInterface {
+class AsyncResolver : public AsyncResolverInterface {
  public:
   AsyncResolver();
   ~AsyncResolver() override;
 
   void Start(const SocketAddress& addr) override;
   bool GetResolvedAddress(int family, SocketAddress* addr) const override;
   int GetError() const override;
   void Destroy(bool wait) override;
 
   const std::vector<IPAddress>& addresses() const { return addresses_; }
   void set_error(int error) { error_ = error; }
 
- protected:
-  void DoWork() override;
-  void OnWorkDone() override;
+ private:
+  // Thread main function

[Taylor Brandstetter, 2017/06/05 22:33:25]

nit: Period?

+  static void ThreadEntry(void *p);

[tommi, 2017/06/08 08:02:10]

void* p
(or even |param|)

can you run git cl format?

[nisse-webrtc, 2017/06/08 09:52:33]

Done.

+  void DoWork();

[tommi, 2017/06/08 08:02:10]

can we have slightly more descriptive names for these methods?

+  void OnWorkDone();
 
- private:
+  rtc::Thread* main_;

[tommi, 2017/06/08 08:02:10]

nit: I'd prefer |thread_| to |main_|.  Actually... what thread is this? If
there's already a general name for it (e.g. the 'signaling' or 'worker' threads
from libjingle), we could name it accordingly.

+  rtc::CriticalSection lock_;

[nisse-webrtc, 2017/06/02 08:41:04]

The use of this lock is maybe overly conservative. 

I don't know if the sigslot machinery itself implies any memory barriers, but I
think the Invoke from the worker thread back to the main thread should be enough
to make stores from the worker thread visible to other threads, right?

[Taylor Brandstetter, 2017/06/05 22:33:25]

It should be enough. Can you try removing the lock? If there are TSan warnings
I'd be surprised.

[nisse-webrtc, 2017/06/07 07:17:31]

Done.

+  PlatformThread worker_;
   SocketAddress addr_;
   std::vector<IPAddress> addresses_;
   int error_;
 };
 
 // rtc namespaced wrappers for inet_ntop and inet_pton so we can avoid
 // the windows-native versions of these.
 const char* inet_ntop(int af, const void *src, char* dst, socklen_t size);
 int inet_pton(int af, const char* src, void *dst);
 
 bool HasIPv4Enabled();
 bool HasIPv6Enabled();
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_NETHELPERS_H_