Mojo: Replace RemotePtr with InterfacePtr and InterfaceImpl

mojo/public/cpp/bindings/interface_ptr.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_INTERFACE_PTR_H_
+#define MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_PTR_H_
+
+#include <assert.h>
+
+#include <algorithm>
+
+#include "mojo/public/cpp/bindings/error_handler.h"
+#include "mojo/public/cpp/bindings/lib/interface_ptr_internal.h"
+#include "mojo/public/cpp/system/macros.h"
+
+namespace mojo {
+class ErrorHandler;
+
+// InterfacePtr represents a proxy to a remote instance of an interface.
+template <typename Interface>
+class InterfacePtr {
+  MOJO_MOVE_ONLY_TYPE_FOR_CPP_03(InterfacePtr, RValue)
+ public:
+  InterfacePtr() {}
+
+  InterfacePtr(RValue other) {
+    other.object->internal_state_.Swap(&internal_state_);
+  }
+  InterfacePtr& operator=(RValue other) {
+    other.object->internal_state_.Swap(&internal_state_);
+    return *this;
+  }
+
+  ~InterfacePtr() {}
+
+  Interface* get() const {
+    return internal_state_.instance();
+  }
+  Interface* operator->() const { return get(); }
+  Interface* operator*() const { return get(); }
+
+  void reset() {
+    State doomed;
+    internal_state_.Swap(&doomed);
+  }
+
+  // This method configures the InterfacePtr<..> to be a proxy to a remote
+  // object on the other end of the given pipe.
+  //
+  // The proxy is bound to the current thread, which means its methods may
+  // only be called on the current thread.
+  //
+  // To move a bound InterfacePtr<..> to another thread, call
+  // ResetAndReturnMessagePipe. Then create a new InterfacePtr<..> on another
+  // thread, and bind the new InterfacePtr<..> to the message pipe on that
+  // thread.
+  void Bind(ScopedMessagePipeHandle handle,
+            MojoAsyncWaiter* waiter = GetDefaultAsyncWaiter()) {
+    reset();
+    internal_state_.ConfigureProxy(handle.Pass(), waiter);
+  }
+
+  // This method may be called to query if the underlying pipe has encountered
+  // an error. If true, this means method calls made on this interface will be
+  // dropped (and may have already been dropped) on the floor.
+  bool encountered_error() const {
+    assert(internal_state_.router());
+    return internal_state_.router()->encountered_error();
+  }
+
+  // This method may be called to register an ErrorHandler to observe a
+  // connection error on the underlying pipe. The callback runs asynchronously
+  // from the current message loop.
+  void set_error_handler(ErrorHandler* error_handler) {
+    assert(internal_state_.router());
+    internal_state_.router()->set_error_handler(error_handler);
+  }
+
+  // Returns the underlying message pipe handle (if any) and resets the
+  // InterfacePtr<..> to its uninitialized state. This method is helpful if you
+  // need to move a proxy to another thread. See related notes for Bind.
+  ScopedMessagePipeHandle ResetAndReturnMessagePipe() {
+    State state;
+    internal_state_.Swap(&state);
+    return state.router() ?
+        state.router()->ReleaseMessagePipe() : ScopedMessagePipeHandle();
+  }
+
+  // DO NOT USE. Exposed only for internal use and for testing.
+  internal::InterfacePtrState<Interface>* internal_state() {
+    return &internal_state_;
+  }
+
+ private:
+  typedef internal::InterfacePtrState<Interface> State;
+  State internal_state_;
+};
+
+// Takes a handle to the proxy end-point of a pipe. On the other end is
+// presumed to be an interface implementation of type |Interface|. Returns a
+// generated proxy to that interface, which may be used on the current thread.
+// It is valid to call SetClient on the returned Interface to set an instance
+// of Interface::Client.
+template <typename Interface>
+InterfacePtr<Interface> MakeProxy(
+    ScopedMessagePipeHandle handle,
+    MojoAsyncWaiter* waiter = GetDefaultAsyncWaiter()) {
+  InterfacePtr<Interface> ptr;
+  if (handle.is_valid())
+    ptr.Bind(handle.Pass(), waiter);
+  return ptr.Pass();
+}
+
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_CPP_BINDINGS_INTERFACE_PTR_H_