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     }
  42     bindings_.clear();
  43   }
  44
  45   bool empty() const { return bindings_.empty(); }
  46
  47  private:
  48   void OnConnectionError() {
  49     // Clear any deleted bindings.
  50     bindings_.erase(
  51         std::remove_if(bindings_.begin(), bindings_.end(),
  52                        [](const base::WeakPtr<WeakBinding<Interface>>& p) {
  53           return p.get() == nullptr;
  54         }),
  55         bindings_.end());
  56
  57     error_handler_.Run();
  58   }
  59
  60   Closure error_handler_;
  61   std::vector<base::WeakPtr<WeakBinding<Interface>>> bindings_;
  62
  63   DISALLOW_COPY_AND_ASSIGN(WeakBindingSet);
  64 };
  65
  66 template <typename Interface>
  67 class WeakBinding {
  68  public:
  69   WeakBinding(Interface* impl, InterfaceRequest<Interface> request)
  70       : binding_(impl, request.Pass()),
  71         weak_ptr_factory_(this) {
  72     binding_.set_connection_error_handler([this]() { OnConnectionError(); });
  73   }
  74
  75   ~WeakBinding() {}
  76
  77   void set_connection_error_handler(const Closure& error_handler) {
  78     error_handler_ = error_handler;
  79   }
  80
  81   base::WeakPtr<WeakBinding> GetWeakPtr() {
  82     return weak_ptr_factory_.GetWeakPtr();
  83   }
  84
  85   void Close() { binding_.Close(); }
  86
  87   void OnConnectionError() {
  88     Closure error_handler = error_handler_;
  89     delete this;
  90     error_handler.Run();
  91   }
  92
  93  private:
  94   Binding<Interface> binding_;
  95   Closure error_handler_;
  96   base::WeakPtrFactory<WeakBinding> weak_ptr_factory_;
  97
  98   DISALLOW_COPY_AND_ASSIGN(WeakBinding);
  99 };
 100
 101 }  // namespace mojo
 102
 103 #endif  // MOJO_COMMON_WEAK_BINDING_SET_H_