Changing SpawnChild to return a struct.

mojo/edk/system/channel_posix.cc

 // 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.
 
 #include "mojo/edk/system/channel.h"
 
 #include <errno.h>
 #include <sys/socket.h>
 
 #include <algorithm>
 #include <deque>
 #include <limits>
 #include <memory>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
 #include "base/synchronization/lock.h"
 #include "base/task_runner.h"
 #include "mojo/edk/embedder/platform_channel_utils_posix.h"
 #include "mojo/edk/embedder/platform_handle_vector.h"
 
 #if !defined(OS_NACL)
 #include <sys/uio.h>
 #endif
 
+#if defined(OS_ANDROID)
+#include "base/android/parcelable_channel_client.h"
+#include "base/android/scoped_java_ref.h"
+#endif
+
 namespace mojo {
 namespace edk {
 
 namespace {
 
 const size_t kMaxBatchReadCapacity = 256 * 1024;
 
 // A view over a Channel::Message object. The write queue uses these since
 // large messages may need to be sent in chunks.
 class MessageView {
  public:
   // Owns |message|. |offset| indexes the first unsent byte in the message.
   MessageView(Channel::MessagePtr message, size_t offset)
-      : message_(std::move(message)),
-        offset_(offset),
-        handles_(message_->TakeHandlesForTransport()) {
+      : message_(std::move(message)), offset_(offset) {
     DCHECK_GT(message_->data_num_bytes(), offset_);
+#if defined(OS_ANDROID)
+    // Parcelables must be retrieved before Handles.
+    ids_and_parcelables_ = message_->TakeParcelablesForTransport();
+#endif
+    handles_ = message_->TakeHandlesForTransport();
   }
 
   MessageView(MessageView&& other) { *this = std::move(other); }
 
   MessageView& operator=(MessageView&& other) {
     message_ = std::move(other.message_);
     offset_ = other.offset_;
     handles_ = std::move(other.handles_);
     return *this;
   }
 
   ~MessageView() {}
 
   const void* data() const {
     return static_cast<const char*>(message_->data()) + offset_;
   }
 
   size_t data_num_bytes() const { return message_->data_num_bytes() - offset_; }
 
   size_t data_offset() const { return offset_; }
   void advance_data_offset(size_t num_bytes) {
     DCHECK_GT(message_->data_num_bytes(), offset_ + num_bytes);
     offset_ += num_bytes;
   }
 
   ScopedPlatformHandleVectorPtr TakeHandles() { return std::move(handles_); }
   Channel::MessagePtr TakeMessage() { return std::move(message_); }
+#if defined(OS_ANDROID)
+  Channel::Message::IDAndParcelableVector TakeParcelables() {
+    return std::move(ids_and_parcelables_);
+  }
+
+#endif
 
   void SetHandles(ScopedPlatformHandleVectorPtr handles) {
     handles_ = std::move(handles);
   }
 
  private:
   Channel::MessagePtr message_;
   size_t offset_;
   ScopedPlatformHandleVectorPtr handles_;
+#if defined(OS_ANDROID)
+  Channel::Message::IDAndParcelableVector ids_and_parcelables_;
+#endif
 
   DISALLOW_COPY_AND_ASSIGN(MessageView);
 };
 
 class ChannelPosix : public Channel,
                      public base::MessageLoop::DestructionObserver,
                      public base::MessageLoopForIO::Watcher {
  public:
   ChannelPosix(Delegate* delegate,
-               ScopedPlatformHandle handle,
+               ConnectionParam connection_param,
                scoped_refptr<base::TaskRunner> io_task_runner)
       : Channel(delegate),
         self_(this),
-        handle_(std::move(handle)),
+        handle_(connection_param.TakeChannelHandle()),
+#if defined(OS_ANDROID)
+        parcelable_channel_client_(
+            connection_param.TakeParcelableChannelClient()),
+        parcelable_channel_server_(
+            connection_param.TakeParcelableChannelServer()),
+#endif
         io_task_runner_(io_task_runner)
 #if defined(OS_MACOSX)
         ,
         handles_to_close_(new PlatformHandleVector)
 #endif
   {
+    CHECK(handle_.is_valid());
+    // We can't DCHECK because the BrokerHost has a channel used for sync
+    // messages with not parcelable channels.
+    // CHECK(parcelable_channel_client_.is_valid());
+    // CHECK(parcelable_channel_server_.is_valid());
   }
 
   void Start() override {
     if (io_task_runner_->RunsTasksOnCurrentThread()) {
       StartOnIOThread();
     } else {
       io_task_runner_->PostTask(
           FROM_HERE, base::Bind(&ChannelPosix::StartOnIOThread, this));
     }
   }
@@ skipping 30 matching lines @@
     leak_handle_ = true;
   }
 
   bool GetReadPlatformHandles(
       size_t num_handles,
       const void* extra_header,
       size_t extra_header_size,
       ScopedPlatformHandleVectorPtr* handles) override {
     if (num_handles > std::numeric_limits<uint16_t>::max())
       return false;
+
 #if defined(OS_MACOSX) && !defined(OS_IOS)
     // On OSX, we can have mach ports which are located in the extra header
     // section.
     using MachPortsEntry = Channel::Message::MachPortsEntry;
     using MachPortsExtraHeader = Channel::Message::MachPortsExtraHeader;
     CHECK(extra_header_size >=
           sizeof(MachPortsExtraHeader) + num_handles * sizeof(MachPortsEntry));
     const MachPortsExtraHeader* mach_ports_header =
         reinterpret_cast<const MachPortsExtraHeader*>(extra_header);
     size_t num_mach_ports = mach_ports_header->num_ports;
@@ skipping 14 matching lines @@
         // These are actually just Mach port names until they're resolved from
         // the remote process.
         (*handles)->at(i).type = PlatformHandle::Type::MACH_NAME;
         mach_port_index++;
       } else {
         CHECK(!incoming_platform_handles_.empty());
         (*handles)->at(i) = incoming_platform_handles_.front();
         incoming_platform_handles_.pop_front();
       }
     }
+#elif defined(OS_ANDROID)
+    using ParcelableEntry = Channel::Message::ParcelableEntry;
+    using ParcelableExtraHeader = Channel::Message::ParcelableExtraHeader;
+    CHECK(extra_header_size >= sizeof(ParcelableExtraHeader) +
+                                   num_handles * sizeof(ParcelableEntry));
+    const ParcelableExtraHeader* parcelable_header =
+        reinterpret_cast<const ParcelableExtraHeader*>(extra_header);
+    size_t num_parcelables = parcelable_header->num_parcelables;
+    CHECK(num_parcelables <= num_handles);
+    if (incoming_platform_handles_.size() + num_parcelables < num_handles) {
+      handles->reset();
+      return true;
+    }
+
+    handles->reset(new PlatformHandleVector(num_handles));
+    const ParcelableEntry* parcelables = parcelable_header->entries;
+    for (size_t i = 0, parcelable_index = 0; i < num_handles; ++i) {
+      if (parcelable_index < num_parcelables &&
+          parcelables[parcelable_index].index == i) {
+        (*handles)->at(i) =
+            PlatformHandle(parcelable_channel_server_.TakeParcelable(
+                parcelables[parcelable_index].id));
+        parcelable_index++;
+      } else {
+        CHECK(!incoming_platform_handles_.empty());
+        (*handles)->at(i) = incoming_platform_handles_.front();
+        incoming_platform_handles_.pop_front();
+      }
+    }
 #else
     if (incoming_platform_handles_.size() < num_handles) {
       handles->reset();
       return true;
     }
 
     handles->reset(new PlatformHandleVector(num_handles));
     for (size_t i = 0; i < num_handles; ++i) {
       (*handles)->at(i) = incoming_platform_handles_.front();
       incoming_platform_handles_.pop_front();
@@ skipping 155 matching lines @@
   bool WriteNoLock(MessageView message_view) {
     if (handle_.get().needs_connection) {
       outgoing_messages_.emplace_front(std::move(message_view));
       return true;
     }
     size_t bytes_written = 0;
     do {
       message_view.advance_data_offset(bytes_written);
 
       ssize_t result;
+#if defined(OS_ANDROID)
+      Channel::Message::IDAndParcelableVector ids_and_parcelables =
+          std::move(message_view.TakeParcelables());
+      if (!ids_and_parcelables.empty()) {
+        for (auto iter = ids_and_parcelables.begin();
+             iter != ids_and_parcelables.end(); ++iter) {
+          DCHECK(!iter->second.is_null());
+          parcelable_channel_client_.SendParcelable(iter->first, iter->second);
+        }
+      }
+#endif
       ScopedPlatformHandleVectorPtr handles = message_view.TakeHandles();
       if (handles && handles->size()) {
         iovec iov = {
           const_cast<void*>(message_view.data()),
           message_view.data_num_bytes()
         };
         // TODO: Handle lots of handles.
         result = PlatformChannelSendmsgWithHandles(
             handle_.get(), &iov, 1, handles->data(), handles->size());
         if (result >= 0) {
@@ skipping 154 matching lines @@
 
     handles_to_close_->erase(start, it);
     return true;
   }
 #endif  // defined(OS_MACOSX)
 
   // Keeps the Channel alive at least until explicit shutdown on the IO thread.
   scoped_refptr<Channel> self_;
 
   ScopedPlatformHandle handle_;
+#if defined(OS_ANDROID)
+  base::android::ParcelableChannelClient parcelable_channel_client_;
+  base::android::ParcelableChannelServer parcelable_channel_server_;
+#endif
   scoped_refptr<base::TaskRunner> io_task_runner_;
 
   // These watchers must only be accessed on the IO thread.
   std::unique_ptr<base::MessageLoopForIO::FileDescriptorWatcher> read_watcher_;
   std::unique_ptr<base::MessageLoopForIO::FileDescriptorWatcher> write_watcher_;
 
   std::deque<PlatformHandle> incoming_platform_handles_;
 
   // Protects |pending_write_| and |outgoing_messages_|.
   base::Lock write_lock_;
   bool pending_write_ = false;
   bool reject_writes_ = false;
   std::deque<MessageView> outgoing_messages_;
 
   bool leak_handle_ = false;
 
 #if defined(OS_MACOSX)
   base::Lock handles_to_close_lock_;
   ScopedPlatformHandleVectorPtr handles_to_close_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(ChannelPosix);
 };
 
 }  // namespace
 
 // static
 scoped_refptr<Channel> Channel::Create(
     Delegate* delegate,
-    ScopedPlatformHandle platform_handle,
+    ConnectionParam connection_param,
     scoped_refptr<base::TaskRunner> io_task_runner) {
-  return new ChannelPosix(delegate, std::move(platform_handle), io_task_runner);
+  return new ChannelPosix(delegate, std::move(connection_param),
+                          io_task_runner);
 }
 
 }  // namespace edk
 }  // namespace mojo