1 files changed, 131 insertions, 0 deletions
diff --git a/netwerk/base/Tickler.h b/netwerk/base/Tickler.h
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+++ b/netwerk/base/Tickler.h
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_net_Tickler_h
+#define mozilla_net_Tickler_h
+
+// The tickler sends a regular 0 byte UDP heartbeat out to a
+// particular address for a short time after it has been touched. This
+// is used on some mobile wifi chipsets to mitigate Power Save Polling
+// (PSP) Mode when we are anticipating a response packet
+// soon. Typically PSP adds 100ms of latency to a read event because
+// the packet delivery is not triggered until the 802.11 beacon is
+// delivered to the host (100ms is the standard Access Point
+// configuration for the beacon interval.) Requesting a frequent
+// transmission and getting a CTS frame from the AP at least that
+// frequently allows for low latency receives when we have reason to
+// expect them (e.g a SYN-ACK).
+//
+// The tickler is used to allow RTT based phases of web transport to
+// complete quickly when on wifi - ARP, DNS, TCP handshake, SSL
+// handshake, HTTP headers, and the TCP slow start phase. The
+// transaction is given up to 400 miliseconds by default to get
+// through those phases before the tickler is disabled.
+//
+// The tickler only applies to wifi on mobile right now. Hopefully it
+// can also be restricted to particular handset models in the future.
+
+#if defined(ANDROID) && !defined(MOZ_B2G)
+#define MOZ_USE_WIFI_TICKLER
+#endif
+
+#include "mozilla/Attributes.h"
+#include "nsISupports.h"
+#include <stdint.h>
+
+#ifdef MOZ_USE_WIFI_TICKLER
+#include "mozilla/Mutex.h"
+#include "mozilla/TimeStamp.h"
+#include "nsAutoPtr.h"
+#include "nsISupports.h"
+#include "nsIThread.h"
+#include "nsITimer.h"
+#include "nsWeakReference.h"
+#include "prio.h"
+
+class nsIPrefBranch;
+#endif
+
+namespace mozilla {
+namespace net {
+
+#ifdef MOZ_USE_WIFI_TICKLER
+
+// 8f769ed6-207c-4af9-9f7e-9e832da3754e
+#define NS_TICKLER_IID \
+{ 0x8f769ed6, 0x207c, 0x4af9, \
+  { 0x9f, 0x7e, 0x9e, 0x83, 0x2d, 0xa3, 0x75, 0x4e } }
+
+class Tickler final : public nsSupportsWeakReference
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_TICKLER_IID)
+
+  // These methods are main thread only
+  Tickler();
+  void Cancel();
+  nsresult Init();
+  void SetIPV4Address(uint32_t address);
+  void SetIPV4Port(uint16_t port);
+
+  // Tickle the tickler to (re-)start the activity.
+  // May call from any thread
+  void Tickle();
+
+private:
+  ~Tickler();
+
+  friend class TicklerTimer;
+  Mutex mLock;
+  nsCOMPtr<nsIThread> mThread;
+  nsCOMPtr<nsITimer> mTimer;
+  nsCOMPtr<nsIPrefBranch> mPrefs;
+
+  bool mActive;
+  bool mCanceled;
+  bool mEnabled;
+  uint32_t mDelay;
+  TimeDuration mDuration;
+  PRFileDesc* mFD;
+
+  TimeStamp mLastTickle;
+  PRNetAddr mAddr;
+
+  // These functions may be called from any thread
+  void PostCheckTickler();
+  void MaybeStartTickler();
+  void MaybeStartTicklerUnlocked();
+
+  // Tickler thread only
+  void CheckTickler();
+  void StartTickler();
+  void StopTickler();
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(Tickler, NS_TICKLER_IID)
+
+#else // not defined MOZ_USE_WIFI_TICKLER
+
+class Tickler final : public nsISupports
+{
+  ~Tickler() { }
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+
+  Tickler() { }
+  nsresult Init() { return NS_ERROR_NOT_IMPLEMENTED; }
+  void Cancel() { }
+  void SetIPV4Address(uint32_t) { };
+  void SetIPV4Port(uint16_t) { }
+  void Tickle() { }
+};
+
+#endif // defined MOZ_USE_WIFI_TICKLER
+
+} // namespace net
+} // namespace mozilla
+
+#endif // mozilla_net_Tickler_h