Implement BroadcastChannel

mojo/public/cpp/bindings/strong_associated_binding.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_PUBLIC_CPP_BINDINGS_STRONG_ASSOCIATED_BINDING_H_
+#define MOJO_PUBLIC_CPP_BINDINGS_STRONG_ASSOCIATED_BINDING_H_
+
+#include <utility>
+
+#include "base/logging.h"
+#include "mojo/public/cpp/bindings/associated_binding.h"
+#include "mojo/public/cpp/bindings/associated_interface_ptr.h"
+#include "mojo/public/cpp/bindings/associated_interface_request.h"
+#include "mojo/public/cpp/bindings/callback.h"
+#include "mojo/public/cpp/system/core.h"
+
+namespace mojo {
+
+// This connects an interface implementation strongly to a pipe. When a
+// connection error is detected the implementation is deleted. Deleting the
+// connector also closes the pipe.
+//
+// This class is thread hostile once it is bound to a message pipe. Until it is
+// bound, it may be bound or destroyed on any thread.
+template <typename Interface>
+class StrongAssociatedBinding {
+  MOVE_ONLY_TYPE_FOR_CPP_03(StrongAssociatedBinding);
+
+ public:
+  explicit StrongAssociatedBinding(Interface* impl) : binding_(impl) {}
+
+  StrongAssociatedBinding(Interface* impl, ScopedMessagePipeHandle handle)
+      : StrongAssociatedBinding(impl) {
+    Bind(std::move(handle));
+  }
+
+  StrongAssociatedBinding(Interface* impl,
+                          AssociatedInterfacePtrInfo<Interface>* ptr_info,
+                          AssociatedGroup* associated_group)
+      : StrongAssociatedBinding(impl) {
+    Bind(ptr_info, associated_group);
+  }
+
+  StrongAssociatedBinding(Interface* impl,
+                          AssociatedInterfaceRequest<Interface> request)
+      : StrongAssociatedBinding(impl) {
+    Bind(std::move(request));
+  }
+
+  ~StrongAssociatedBinding() {}
+
+  void Bind(AssociatedInterfacePtrInfo<Interface>* ptr_info,
+            AssociatedGroup* associated_group) {
+    DCHECK(!binding_.is_bound());
+    binding_.Bind(ptr_info, associated_group);
+    binding_.set_connection_error_handler([this]() { OnConnectionError(); });
+  }
+
+  void Bind(AssociatedInterfaceRequest<Interface> request) {
+    DCHECK(!binding_.is_bound());
+    binding_.Bind(std::move(request));
+    binding_.set_connection_error_handler([this]() { OnConnectionError(); });
+  }
+
+  // Note: The error handler must not delete the interface implementation.
+  //
+  // This method may only be called after this AssociatedStrongBinding has been
+  // bound to a message pipe.
+  void set_connection_error_handler(const Closure& error_handler) {
+    DCHECK(binding_.is_bound());
+    connection_error_handler_ = error_handler;
+  }
+
+  Interface* impl() { return binding_.impl(); }
+
+  void OnConnectionError() {
+    connection_error_handler_.Run();
+    delete binding_.impl();
+  }
+
+ private:
+  Closure connection_error_handler_;
+  AssociatedBinding<Interface> binding_;
+};
+
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_CPP_BINDINGS_STRONG_ASSOCIATED_BINDING_H_