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   // NOTE: Deprecated. Please use the method above.
  32   // TODO(yzshen): Remove this method once all callsites are converted.
  33   void set_error_handler(ErrorHandler* error_handler) {
  34     if (error_handler) {
  35       set_connection_error_handler(
  36           [error_handler]() { error_handler->OnConnectionError(); });
  37     } else {
  38       set_connection_error_handler(Closure());
  39     }
  40   }
  41
  42   void AddBinding(Interface* impl, InterfaceRequest<Interface> request) {
  43     auto binding = new WeakBinding<Interface>(impl, request.Pass());
  44     binding->set_connection_error_handler([this]() { OnConnectionError(); });
  45     bindings_.push_back(binding->GetWeakPtr());
  46   }
  47
  48   void CloseAllBindings() {
  49     for (const auto& it : bindings_) {
  50       if (it)
  51         it->Close();
  52     }
  53     bindings_.clear();
  54   }
  55
  56   bool empty() const { return bindings_.empty(); }
  57
  58  private:
  59   void OnConnectionError() {
  60     // Clear any deleted bindings.
  61     bindings_.erase(
  62         std::remove_if(bindings_.begin(), bindings_.end(),
  63                        [](const base::WeakPtr<WeakBinding<Interface>>& p) {
  64           return p.get() == nullptr;
  65         }),
  66         bindings_.end());
  67
  68     error_handler_.Run();
  69   }
  70
  71   Closure error_handler_;
  72   std::vector<base::WeakPtr<WeakBinding<Interface>>> bindings_;
  73
  74   DISALLOW_COPY_AND_ASSIGN(WeakBindingSet);
  75 };
  76
  77 template <typename Interface>
  78 class WeakBinding {
  79  public:
  80   WeakBinding(Interface* impl, InterfaceRequest<Interface> request)
  81       : binding_(impl, request.Pass()),
  82         weak_ptr_factory_(this) {
  83     binding_.set_connection_error_handler([this]() { OnConnectionError(); });
  84   }
  85
  86   ~WeakBinding() {}
  87
  88   void set_connection_error_handler(const Closure& error_handler) {
  89     error_handler_ = error_handler;
  90   }
  91
  92   base::WeakPtr<WeakBinding> GetWeakPtr() {
  93     return weak_ptr_factory_.GetWeakPtr();
  94   }
  95
  96   void Close() { binding_.Close(); }
  97
  98   void OnConnectionError() {
  99     Closure error_handler = error_handler_;
 100     delete this;
 101     error_handler.Run();
 102   }
 103
 104  private:
 105   Binding<Interface> binding_;
 106   Closure error_handler_;
 107   base::WeakPtrFactory<WeakBinding> weak_ptr_factory_;
 108
 109   DISALLOW_COPY_AND_ASSIGN(WeakBinding);
 110 };
 111
 112 }  // namespace mojo
 113
 114 #endif  // MOJO_COMMON_WEAK_BINDING_SET_H_