Create an experiment to study whether too many bindings cause NAT failure

content/renderer/media/webrtc/stun_field_trial.h

Index: content/renderer/media/webrtc/stun_field_trial.h
diff --git a/content/renderer/media/webrtc/stun_field_trial.h b/content/renderer/media/webrtc/stun_field_trial.h
index 4095bede6812c01ab81f8b934d2f642a2731e52f..82ab259a45ddfbd37c1c7db5b4e36f5308092015 100644
--- a/content/renderer/media/webrtc/stun_field_trial.h
+++ b/content/renderer/media/webrtc/stun_field_trial.h
@@ -8,41 +8,92 @@
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
 #include "content/common/content_export.h"
+#include "content/renderer/p2p/network_list_manager.h"
+#include "content/renderer/p2p/network_list_observer.h"
 #include "third_party/webrtc/base/network.h"
+#include "third_party/webrtc/base/sigslot.h"
+#include "third_party/webrtc/p2p/stunprober/stunprober.h"
 
 namespace rtc {
 class PacketSocketFactory;
 class SocketAddress;
 }  // namespace rtc
 
-namespace stunprober {
-class StunProber;
-}  // namespace stunprober
-
 namespace content {
 
+using StunProber = stunprober::StunProber;
+
+// Helper class to link the StunProbers together such that the first STUN ping
+// in the next prober could be sent at the same interval as inside a
+// prober. This is to maintain the consistency of intervals across the whole
+// trial.
+class StunProberWithWeakPtr {

[pthatcher2, 2015/10/29 14:13:13]

This still seems an awkward way of storing a list (a linked list of weak
pointers).  What's the reason for it?

[guoweis_webrtc, 2015/10/29 21:45:30]

If the pc gets deleted after a Start has been scheduled on the next prober, this
will prevent the crash.

+ public:
+  StunProberWithWeakPtr(StunProber* prober);
+  virtual ~StunProberWithWeakPtr();
+  void set_next_prober(StunProberWithWeakPtr* prober);
+  void Start(StunProber::Observer* observer);
+  base::WeakPtr<StunProberWithWeakPtr> GetWeakPtr() {
+    return weak_factory_.GetWeakPtr();
+  }
+  bool GetStats(StunProber::Stats* stats) { return prober_->GetStats(stats); }
+  StunProberWithWeakPtr* GetNextProber() { return next_prober_; }
+
+ private:
+  scoped_ptr<StunProber> prober_;
+  StunProberWithWeakPtr* next_prober_ = nullptr;
+  base::WeakPtrFactory<StunProberWithWeakPtr> weak_factory_;
+};
+
 // Wait for 30 seconds to avoid high CPU usage during browser start-up which
 // might affect the accuracy of the trial. The trial wakes up the browser every
 // 1 ms for no more than 3 seconds to see if time has passed for sending next
 // stun probe.
 static const int kExperimentStartDelayMs = 30000;
 
-// This will use |factory| to create sockets, send stun binding requests with
-// various intervals as determined by |params|, observed the success rate and
-// latency of the stun responses and report through UMA.
-scoped_ptr<stunprober::StunProber> StartStunProbeTrial(
-    const rtc::NetworkManager::NetworkList& networks,
-    const std::string& params,
-    rtc::PacketSocketFactory* factory);
-
-// Parsing function to decode the '/' separated parameter string |params|.
-CONTENT_EXPORT bool ParseStunProbeParameters(
-    const std::string& params,
-    int* requests_per_ip,
-    int* interval_ms,
-    int* shared_socket_mode,
-    std::vector<rtc::SocketAddress>* servers);
+class StunProberTrial : public StunProber::Observer,
+                        public sigslot::has_slots<> {
+ public:
+  StunProberTrial(rtc::NetworkManager* network_manager,
+                  const std::string& params,
+                  rtc::PacketSocketFactory* factory);
+  ~StunProberTrial() override;
+
+  // This will use |factory| to create sockets, send stun binding requests with

[pthatcher2, 2015/10/29 14:13:13]

|factory_|?

[guoweis_webrtc, 2015/10/29 21:45:30]

Done.

+  // various intervals as determined by |params|, observed the success rate and
+  // latency of the stun responses and report through UMA.
+  void OnNetworksChanged();
+
+  // Parsing function to decode the '/' separated parameter string |params|.
+  static CONTENT_EXPORT bool ParseParameters(
+      const std::string& params,
+      int* requests_per_ip,
+      int* interval_ms,
+      int* shared_socket_mode,
+      int* batch_size,
+      int* total_batches,
+      std::vector<rtc::SocketAddress>* servers);
+
+  // stunprober::StunProber::Observer
+  void OnPrepared(StunProber* prober, StunProber::Status status) override;
+  void OnFinished(StunProber* prober, StunProber::Status status) override;
+
+ private:
+  void SaveHistogramData();
+
+  rtc::NetworkManager* network_manager_;
+  std::string params_;
+  rtc::PacketSocketFactory* factory_ = nullptr;
+  int total_probers_ = 0;
+  int batch_size_ = 0;
+  int ready_probers_ = 0;
+  int finished_probers_ = 0;
+  scoped_ptr<StunProberWithWeakPtr> prober_head_;
+  base::ThreadChecker thread_checker_;
+};
 
 }  // namespace content