tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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notifier.h (2143B)

      1 /*
      2 *  Copyright 2011 The WebRTC project authors. All Rights Reserved.
      3 *
      4 *  Use of this source code is governed by a BSD-style license
      5 *  that can be found in the LICENSE file in the root of the source
      6 *  tree. An additional intellectual property rights grant can be found
      7 *  in the file PATENTS.  All contributing project authors may
      8 *  be found in the AUTHORS file in the root of the source tree.
      9 */
     10 
     11 #ifndef API_NOTIFIER_H_
     12 #define API_NOTIFIER_H_
     13 
     14 #include <list>
     15 
     16 #include "api/media_stream_interface.h"
     17 #include "api/sequence_checker.h"
     18 #include "rtc_base/checks.h"
     19 #include "rtc_base/system/no_unique_address.h"
     20 #include "rtc_base/thread_annotations.h"
     21 
     22 namespace webrtc {
     23 
     24 // Implements a template version of a notifier.
     25 // TODO(deadbeef): This is an implementation detail; move out of api/.
     26 template <class T>
     27 class Notifier : public T {
     28 public:
     29  Notifier() = default;
     30 
     31  virtual void RegisterObserver(ObserverInterface* observer) {
     32    RTC_DCHECK_RUN_ON(&sequence_checker_);
     33    RTC_DCHECK(observer != nullptr);
     34    observers_.push_back(observer);
     35  }
     36 
     37  virtual void UnregisterObserver(ObserverInterface* observer) {
     38    RTC_DCHECK_RUN_ON(&sequence_checker_);
     39    for (std::list<ObserverInterface*>::iterator it = observers_.begin();
     40         it != observers_.end(); it++) {
     41      if (*it == observer) {
     42        observers_.erase(it);
     43        break;
     44      }
     45    }
     46  }
     47 
     48  void FireOnChanged() {
     49    RTC_DCHECK_RUN_ON(&sequence_checker_);
     50    // Copy the list of observers to avoid a crash if the observer object
     51    // unregisters as a result of the OnChanged() call. If the same list is used
     52    // UnregisterObserver will affect the list make the iterator invalid.
     53    std::list<ObserverInterface*> observers = observers_;
     54    for (std::list<ObserverInterface*>::iterator it = observers.begin();
     55         it != observers.end(); ++it) {
     56      (*it)->OnChanged();
     57    }
     58  }
     59 
     60 protected:
     61  std::list<ObserverInterface*> observers_ RTC_GUARDED_BY(sequence_checker_);
     62 
     63 private:
     64  RTC_NO_UNIQUE_ADDRESS SequenceChecker sequence_checker_{
     65      SequenceChecker::kDetached};
     66 };
     67 
     68 }  // namespace webrtc
     69 
     70 #endif  // API_NOTIFIER_H_