Roll mojo SDK to 734c6e1652ff2f3b696e441722838f453f4f9b42

mojo/common/weak_interface_ptr_set.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_COMMON_WEAK_INTERFACE_PTR_SET_H_
 #define MOJO_COMMON_WEAK_INTERFACE_PTR_SET_H_
 
 #include <vector>
 
+#include "base/logging.h"
 #include "base/memory/weak_ptr.h"
-#include "third_party/mojo/src/mojo/public/cpp/bindings/interface_ptr.h"
+#include "mojo/public/cpp/bindings/interface_ptr.h"
 
 namespace mojo {
 
+namespace internal {
+
+// TODO(vtl): This name of this class is a little odd -- it's not a "weak
+// pointer", but a wrapper around InterfacePtr that owns itself and can vend
+// weak pointers to itself. Probably, with connection error callbacks instead of
+// ErrorHandlers, this class is unneeded, and WeakInterfacePtrSet can simply
+// own/remove interface pointers as connection errors occur.
+// https://github.com/domokit/mojo/issues/311
 template <typename Interface>
-class WeakInterfacePtr;
+class WeakInterfacePtr {
+ public:
+  explicit WeakInterfacePtr(InterfacePtr<Interface> ptr)
+      : ptr_(ptr.Pass()), weak_ptr_factory_(this) {
+    ptr_.set_connection_error_handler([this]() { delete this; });
+  }
+  ~WeakInterfacePtr() {}
 
+  void Close() { ptr_.reset(); }
+
+  Interface* get() { return ptr_.get(); }
+
+  base::WeakPtr<WeakInterfacePtr> GetWeakPtr() {
+    return weak_ptr_factory_.GetWeakPtr();
+  }
+
+ private:
+  InterfacePtr<Interface> ptr_;
+  base::WeakPtrFactory<WeakInterfacePtr> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(WeakInterfacePtr);
+};
+
+}  // namespace internal
+
+// A WeakInterfacePtrSet contains a collection of InterfacePtrs
+// that are automatically removed from the collection and destroyed
+// when their associated MessagePipe experiences a connection error.
+// When the set is destroyed all of the MessagePipes will be closed.
+// TODO(rudominer) Rename this class since the ownership of the elements
+// is not "weak" from the point of view of the client.
 template <typename Interface>
 class WeakInterfacePtrSet {
  public:
   WeakInterfacePtrSet() {}
   ~WeakInterfacePtrSet() { CloseAll(); }
 
+  // |ptr| must be bound to a message pipe.
   void AddInterfacePtr(InterfacePtr<Interface> ptr) {
-    auto weak_interface_ptr = new WeakInterfacePtr<Interface>(ptr.Pass());
+    DCHECK(ptr.is_bound());
+    auto weak_interface_ptr =
+        new internal::WeakInterfacePtr<Interface>(ptr.Pass());
     ptrs_.push_back(weak_interface_ptr->GetWeakPtr());
     ClearNullInterfacePtrs();
   }
 
+  // Applies |function| to each of the InterfacePtrs in the set.
   template <typename FunctionType>
   void ForAllPtrs(FunctionType function) {
     for (const auto& it : ptrs_) {
       if (it)
         function(it->get());
     }
     ClearNullInterfacePtrs();
   }
 
+  // Closes the MessagePipe associated with each of the InterfacePtrs in
+  // this set and clears the set.
   void CloseAll() {
     for (const auto& it : ptrs_) {
       if (it)
         it->Close();
     }
     ptrs_.clear();
   }
 
+  // TODO(rudominer) After reworking this class and eliminating the method
+  // ClearNullInterfacePtrs, this method should become const.
+  size_t size() {
+    ClearNullInterfacePtrs();
+    return ptrs_.size();
+  }
+
  private:
-  using WPWIPI = base::WeakPtr<WeakInterfacePtr<Interface>>;
+  using WPWIPI = base::WeakPtr<internal::WeakInterfacePtr<Interface>>;
 
   void ClearNullInterfacePtrs() {
     ptrs_.erase(std::remove_if(ptrs_.begin(), ptrs_.end(), [](const WPWIPI& p) {
       return p.get() == nullptr;
     }), ptrs_.end());
   }
 
   std::vector<WPWIPI> ptrs_;
 };
 
-template <typename Interface>
-class WeakInterfacePtr : public ErrorHandler {
- public:
-  explicit WeakInterfacePtr(InterfacePtr<Interface> ptr)
-      : ptr_(ptr.Pass()), weak_ptr_factory_(this) {
-    ptr_.set_error_handler(this);
-  }
-  ~WeakInterfacePtr() override {}
-
-  void Close() { ptr_.reset(); }
-
-  Interface* get() { return ptr_.get(); }
-
-  base::WeakPtr<WeakInterfacePtr> GetWeakPtr() {
-    return weak_ptr_factory_.GetWeakPtr();
-  }
-
- private:
-  // ErrorHandler implementation
-  void OnConnectionError() override { delete this; }
-
-  InterfacePtr<Interface> ptr_;
-  base::WeakPtrFactory<WeakInterfacePtr> weak_ptr_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(WeakInterfacePtr);
-};
-
 }  // namespace mojo
 
 #endif  // MOJO_COMMON_WEAK_INTERFACE_PTR_SET_H_