mojo/common/weak_binding_set.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MOJO_COMMON_WEAK_BINDING_SET_H_
   6 #define MOJO_COMMON_WEAK_BINDING_SET_H_
   7
   8 #include <algorithm>
   9 #include <vector>
  10
  11 #include "base/memory/weak_ptr.h"
  12 #include "third_party/mojo/src/mojo/public/cpp/bindings/binding.h"
  13
  14 namespace mojo {
  15
  16 template <typename Interface>
  17 class WeakBinding;
  18
  19 // Use this class to manage a set of weak pointers to bindings each of which is
  20 // owned by the pipe they are bound to.
  21 template <typename Interface>
  22 class WeakBindingSet {
  23  public:
  24   WeakBindingSet() {}
  25   ~WeakBindingSet() { CloseAllBindings(); }
  26
  27   void set_connection_error_handler(const Closure& error_handler) {
  28     error_handler_ = error_handler;
  29   }
  30
  31   void AddBinding(Interface* impl, InterfaceRequest<Interface> request) {
  32     auto binding = new WeakBinding<Interface>(impl, request.Pass());
  33     binding->set_connection_error_handler([this]() { OnConnectionError(); });
  34     bindings_.push_back(binding->GetWeakPtr());
  35   }
  36
  37   void CloseAllBindings() {
  38     for (const auto& it : bindings_) {
  39       if (it) {
  40         it->Close();
  41         delete it.get();
  42       }
  43     }
  44     bindings_.clear();
  45   }
  46
  47   bool empty() const { return bindings_.empty(); }
  48
  49  private:
  50   void OnConnectionError() {
  51     // Clear any deleted bindings.
  52     bindings_.erase(
  53         std::remove_if(bindings_.begin(), bindings_.end(),
  54                        [](const base::WeakPtr<WeakBinding<Interface>>& p) {
  55           return p.get() == nullptr;
  56         }),
  57         bindings_.end());
  58
  59     error_handler_.Run();
  60   }
  61
  62   Closure error_handler_;
  63   std::vector<base::WeakPtr<WeakBinding<Interface>>> bindings_;
  64
  65   DISALLOW_COPY_AND_ASSIGN(WeakBindingSet);
  66 };
  67
  68 template <typename Interface>
  69 class WeakBinding {
  70  public:
  71   WeakBinding(Interface* impl, InterfaceRequest<Interface> request)
  72       : binding_(impl, request.Pass()),
  73         weak_ptr_factory_(this) {
  74     binding_.set_connection_error_handler([this]() { OnConnectionError(); });
  75   }
  76
  77   ~WeakBinding() {}
  78
  79   void set_connection_error_handler(const Closure& error_handler) {
  80     error_handler_ = error_handler;
  81   }
  82
  83   base::WeakPtr<WeakBinding> GetWeakPtr() {
  84     return weak_ptr_factory_.GetWeakPtr();
  85   }
  86
  87   void Close() { binding_.Close(); }
  88
  89   void OnConnectionError() {
  90     Closure error_handler = error_handler_;
  91     delete this;
  92     error_handler.Run();
  93   }
  94
  95  private:
  96   Binding<Interface> binding_;
  97   Closure error_handler_;
  98   base::WeakPtrFactory<WeakBinding> weak_ptr_factory_;
  99
 100   DISALLOW_COPY_AND_ASSIGN(WeakBinding);
 101 };
 102
 103 }  // namespace mojo
 104
 105 #endif  // MOJO_COMMON_WEAK_BINDING_SET_H_