Mojo C++ Bindings: Eliminate unbound ThreadSafeInterfacePtr

mojo/public/cpp/bindings/thread_safe_interface_ptr.h

 // Copyright 2016 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_THREAD_SAFE_INTERFACE_PTR_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_THREAD_SAFE_INTERFACE_PTR_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 33 matching lines @@
 // methods on the ThreadSafeInterfacePtr before it is bound.
 
 template <typename Interface, template <typename> class InterfacePtrType>
 class ThreadSafeInterfacePtrBase
     : public MessageReceiverWithResponder,
       public base::RefCountedThreadSafe<
           ThreadSafeInterfacePtrBase<Interface, InterfacePtrType>,
           ThreadSafeInterfacePtrDeleter> {
  public:
   using ProxyType = typename Interface::Proxy_;
+  using PtrInfoType = typename InterfacePtrType<Interface>::PtrInfoType;
 
+  // Creates a ThreadSafeInterfacePtrBase wrapping an underlying non-thread-safe
+  // InterfacePtrType which is bound to the calling thread. All messages sent
+  // via this thread-safe proxy will internally be sent by first posting to this
+  // (the calling) thread's TaskRunner.
   static scoped_refptr<ThreadSafeInterfacePtrBase<Interface, InterfacePtrType>>
   Create(InterfacePtrType<Interface> interface_ptr) {
     scoped_refptr<ThreadSafeInterfacePtrBase> ptr(
         new ThreadSafeInterfacePtrBase());
-    return ptr->Bind(std::move(interface_ptr)) ? ptr : nullptr;
+    ptr->interface_ptr_task_runner_ = base::ThreadTaskRunnerHandle::Get();
+    return ptr->Bind(interface_ptr.PassInterface()) ? ptr : nullptr;
   }
 
-  // Creates a ThreadSafeInterfacePtrBase with no associated InterfacePtr.
-  // Call Bind() with the InterfacePtr once available, which must be called on
-  // the |bind_task_runner|.
-  // Providing the TaskRunner here allows you to post a task to
-  // |bind_task_runner| to do the bind and then immediately start calling
-  // methods on the returned interface.
+  // Creates a ThreadSafeInterfacePtrBase which binds the underlying
+  // non-thread-safe InterfacePtrType on the specified TaskRunner. All messages
+  // sent via this thread-safe proxy will internally be sent by first posting to
+  // that TaskRunner.
   static scoped_refptr<ThreadSafeInterfacePtrBase<Interface, InterfacePtrType>>
-  CreateUnbound(
-      const scoped_refptr<base::SingleThreadTaskRunner>& bind_task_runner) {
+  Create(PtrInfoType ptr_info,
+         const scoped_refptr<base::SingleThreadTaskRunner>& bind_task_runner) {
     scoped_refptr<ThreadSafeInterfacePtrBase<Interface, InterfacePtrType>> ptr =
         new ThreadSafeInterfacePtrBase();
     ptr->interface_ptr_task_runner_ = bind_task_runner;
+    bind_task_runner->PostTask(
+        FROM_HERE,
+        base::Bind(base::IgnoreResult(&ThreadSafeInterfacePtrBase::Bind), ptr,
+                   base::Passed(&ptr_info)));
     return ptr;
   }
 
   // Binds a ThreadSafeInterfacePtrBase previously created with CreateUnbound().
-  // This must be called on the thread that |interface_ptr| should be used.
+  // This must be called on the thread that |ptr_info| should be used.
   // If created with CreateUnbound() that thread should be the same as the one
   // provided at creation time.
-  bool Bind(InterfacePtrType<Interface> interface_ptr) {
-    DCHECK(!interface_ptr_task_runner_ ||
-        interface_ptr_task_runner_ == base::ThreadTaskRunnerHandle::Get());
-    if (!interface_ptr.is_bound()) {
+  bool Bind(PtrInfoType ptr_info) {
+    DCHECK_EQ(interface_ptr_task_runner_, base::ThreadTaskRunnerHandle::Get());
+    if (!ptr_info.is_valid()) {
       LOG(ERROR) << "Attempting to bind a ThreadSafe[Associated]InterfacePtr "
                     "from an unbound InterfacePtr.";
       return false;
     }
-    interface_ptr_ = std::move(interface_ptr);
-    interface_ptr_task_runner_ = base::ThreadTaskRunnerHandle::Get();
+    interface_ptr_.Bind(std::move(ptr_info));
     return true;
   }
 
   ~ThreadSafeInterfacePtrBase() override {}
 
   Interface* get() { return &proxy_; }
   Interface* operator->() { return get(); }
   Interface& operator*() { return *get(); }
 
  private:
@@ skipping 93 matching lines @@
 using ThreadSafeAssociatedInterfacePtr =
     ThreadSafeInterfacePtrBase<Interface, AssociatedInterfacePtr>;
 
 template <typename Interface>
 using ThreadSafeInterfacePtr =
     ThreadSafeInterfacePtrBase<Interface, InterfacePtr>;
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_THREAD_SAFE_INTERFACE_PTR_H_