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/*
* Copyright (C) 2008 Apple Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef NetworkStateNotifier_h
#define NetworkStateNotifier_h
#include "core/CoreExport.h"
#include "core/dom/ExecutionContext.h"
#include "public/platform/WebConnectionType.h"
#include "wtf/Allocator.h"
#include "wtf/HashMap.h"
#include "wtf/Noncopyable.h"
#include "wtf/ThreadingPrimitives.h"
#include "wtf/Vector.h"
#include <memory>
namespace blink {
class CORE_EXPORT NetworkStateNotifier {
WTF_MAKE_NONCOPYABLE(NetworkStateNotifier);
USING_FAST_MALLOC(NetworkStateNotifier);
public:
class NetworkStateObserver {
public:
// Will be called on the thread of the context passed in addObserver.
virtual void connectionChange(WebConnectionType,
double maxBandwidthMbps) = 0;
};
NetworkStateNotifier() : m_hasOverride(false) {}
// Can be called on any thread.
bool onLine() const {
MutexLocker locker(m_mutex);
const NetworkState& state = m_hasOverride ? m_override : m_state;
DCHECK(state.onLineInitialized);
return state.onLine;
}
void setOnLine(bool);
// Can be called on any thread.
WebConnectionType connectionType() const {
MutexLocker locker(m_mutex);
const NetworkState& state = m_hasOverride ? m_override : m_state;
DCHECK(state.connectionInitialized);
return state.type;
}
// Can be called on any thread.
bool isCellularConnectionType() const {
switch (connectionType()) {
case WebConnectionTypeCellular2G:
case WebConnectionTypeCellular3G:
case WebConnectionTypeCellular4G:
return true;
case WebConnectionTypeBluetooth:
case WebConnectionTypeEthernet:
case WebConnectionTypeWifi:
case WebConnectionTypeWimax:
case WebConnectionTypeOther:
case WebConnectionTypeNone:
case WebConnectionTypeUnknown:
return false;
}
ASSERT_NOT_REACHED();
return false;
}
// Can be called on any thread.
double maxBandwidth() const {
MutexLocker locker(m_mutex);
const NetworkState& state = m_hasOverride ? m_override : m_state;
DCHECK(state.connectionInitialized);
return state.maxBandwidthMbps;
}
void setWebConnection(WebConnectionType, double maxBandwidthMbps);
// When called, successive setWebConnectionType/setOnLine calls are stored,
// and supplied overridden values are used instead until clearOverride() is
// called. This is used for layout tests (see crbug.com/377736) and inspector
// emulation.
//
// Since this class is a singleton, tests must clear override when completed
// to avoid indeterminate state across the test harness.
void setOverride(bool onLine, WebConnectionType, double maxBandwidthMbps);
void clearOverride();
// Must be called on the context's thread. An added observer must be removed
// before its ExecutionContext is deleted. It's possible for an observer to
// be called twice for the same event if it is first removed and then added
// during notification.
void addObserver(NetworkStateObserver*, ExecutionContext*);
void removeObserver(NetworkStateObserver*, ExecutionContext*);
private:
struct ObserverList {
ObserverList() : iterating(false) {}
bool iterating;
Vector<NetworkStateObserver*> observers;
Vector<size_t> zeroedObservers; // Indices in observers that are 0.
};
struct NetworkState {
static const int kInvalidMaxBandwidth = -1;
bool onLineInitialized = false;
bool onLine = true;
bool connectionInitialized = false;
WebConnectionType type = WebConnectionTypeOther;
double maxBandwidthMbps = kInvalidMaxBandwidth;
};
// This helper scope issues required notifications when mutating the state if
// something has changed. It's only possible to mutate the state on the main
// thread. Note that ScopedNotifier must be destroyed when not holding a lock
// so that onLine notifications can be dispatched without a deadlock.
class ScopedNotifier {
public:
explicit ScopedNotifier(NetworkStateNotifier&);
~ScopedNotifier();
private:
NetworkStateNotifier& m_notifier;
NetworkState m_before;
};
// The ObserverListMap is cross-thread accessed, adding/removing Observers
// running within an ExecutionContext. Kept off-heap to ease cross-thread
// allocation and use; the observers are (already) responsible for explicitly
// unregistering while finalizing.
using ObserverListMap =
HashMap<UntracedMember<ExecutionContext>, std::unique_ptr<ObserverList>>;
void notifyObservers(WebConnectionType, double maxBandwidthMbps);
void notifyObserversOfConnectionChangeOnContext(WebConnectionType,
double maxBandwidthMbps,
ExecutionContext*);
ObserverList* lockAndFindObserverList(ExecutionContext*);
// Removed observers are nulled out in the list in case the list is being
// iterated over. Once done iterating, call this to clean up nulled
// observers.
void collectZeroedObservers(ObserverList*, ExecutionContext*);
mutable Mutex m_mutex;
NetworkState m_state;
bool m_hasOverride;
NetworkState m_override;
ObserverListMap m_observers;
};
CORE_EXPORT NetworkStateNotifier& networkStateNotifier();
} // namespace blink
#endif // NetworkStateNotifier_h
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