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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_PROXY_BYPASS_PROTECTION)
# 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 "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() = default;
public:
NS_DECL_THREADSAFE_ISUPPORTS
Tickler() = default;
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