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      1 /*
      2  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef NetworkStateNotifier_h
     27 #define NetworkStateNotifier_h
     28 
     29 #include "public/platform/WebConnectionType.h"
     30 #include "wtf/FastAllocBase.h"
     31 #include "wtf/HashMap.h"
     32 #include "wtf/Noncopyable.h"
     33 #include "wtf/ThreadingPrimitives.h"
     34 #include "wtf/Vector.h"
     35 
     36 namespace blink {
     37 
     38 class ExecutionContext;
     39 
     40 class NetworkStateNotifier {
     41     WTF_MAKE_NONCOPYABLE(NetworkStateNotifier); WTF_MAKE_FAST_ALLOCATED;
     42 public:
     43     class NetworkStateObserver {
     44     public:
     45         // Will be called on the thread of the context passed in addObserver.
     46         virtual void connectionTypeChange(blink::WebConnectionType) = 0;
     47     };
     48 
     49     NetworkStateNotifier()
     50         : m_isOnLine(true)
     51         , m_type(blink::ConnectionTypeOther)
     52         , m_testUpdatesOnly(false)
     53     {
     54     }
     55 
     56     bool onLine() const
     57     {
     58         MutexLocker locker(m_mutex);
     59         return m_isOnLine;
     60     }
     61 
     62     void setOnLine(bool);
     63 
     64     blink::WebConnectionType connectionType() const
     65     {
     66         MutexLocker locker(m_mutex);
     67         return m_type;
     68     }
     69 
     70     void setWebConnectionType(blink::WebConnectionType);
     71 
     72     // Must be called on the context's thread. An added observer must be removed
     73     // before its ExecutionContext is deleted. It's possible for an observer to
     74     // be called twice for the same event if it is first removed and then added
     75     // during notification.
     76     void addObserver(NetworkStateObserver*, ExecutionContext*);
     77     void removeObserver(NetworkStateObserver*, ExecutionContext*);
     78 
     79     // The following functions are for testing purposes.
     80 
     81     // When true, setWebConnectionType calls are ignored and only setWebConnectionTypeForTest
     82     // can update the connection type. This is used for layout tests (see crbug.com/377736).
     83     void setTestUpdatesOnly(bool);
     84     // Tests should call this as it will change the type regardless of the value of m_testUpdatesOnly.
     85     void setWebConnectionTypeForTest(blink::WebConnectionType);
     86 
     87 private:
     88     struct ObserverList {
     89         ObserverList()
     90             : iterating(false)
     91         {
     92         }
     93         bool iterating;
     94         Vector<NetworkStateObserver*> observers;
     95         Vector<size_t> zeroedObservers; // Indices in observers that are 0.
     96     };
     97 
     98     void setWebConnectionTypeImpl(blink::WebConnectionType);
     99 
    100     typedef HashMap<ExecutionContext*, OwnPtr<ObserverList> > ObserverListMap;
    101 
    102     void notifyObserversOnContext(ExecutionContext*, blink::WebConnectionType);
    103 
    104     ObserverList* lockAndFindObserverList(ExecutionContext*);
    105 
    106     // Removed observers are nulled out in the list in case the list is being
    107     // iterated over. Once done iterating, call this to clean up nulled
    108     // observers.
    109     void collectZeroedObservers(ObserverList*, ExecutionContext*);
    110 
    111     mutable Mutex m_mutex;
    112     bool m_isOnLine;
    113     blink::WebConnectionType m_type;
    114     ObserverListMap m_observers;
    115     bool m_testUpdatesOnly;
    116 };
    117 
    118 NetworkStateNotifier& networkStateNotifier();
    119 
    120 } // namespace blink
    121 
    122 #endif // NetworkStateNotifier_h
    123