Create a broker interface for the new Mojo EDK so that the browser can create and duplicate messa...

mojo/edk/embedder/platform_channel_pair_win.cc

 // 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.
 
 #include "mojo/edk/embedder/platform_channel_pair.h"
 
 #include <windows.h>
 
 #include <string>
 
@@ skipping 11 matching lines @@
 namespace {
 
 std::wstring GeneratePipeName() {
   return base::StringPrintf(L"\\\\.\\pipe\\mojo.%u.%u.%I64u",
                             GetCurrentProcessId(), GetCurrentThreadId(),
                             base::RandUint64());
 }
 
 }  // namespace
 
-PlatformChannelPair::PlatformChannelPair() {
+PlatformChannelPair::PlatformChannelPair(bool client_is_blocking) {
   std::wstring pipe_name = GeneratePipeName();
 
-  const DWORD kOpenMode =
+  DWORD kOpenMode =
       PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED | FILE_FLAG_FIRST_PIPE_INSTANCE;
   const DWORD kPipeMode = PIPE_TYPE_BYTE | PIPE_READMODE_BYTE;
   server_handle_.reset(PlatformHandle(
       CreateNamedPipeW(pipe_name.c_str(), kOpenMode, kPipeMode,
                        1,           // Max instances.
                        4096,        // Out buffer size.
                        4096,        // In buffer size.
                        5000,        // Timeout in milliseconds.
                        nullptr)));  // Default security descriptor.
   PCHECK(server_handle_.is_valid());
 
   const DWORD kDesiredAccess = GENERIC_READ | GENERIC_WRITE;
   // The SECURITY_ANONYMOUS flag means that the server side cannot impersonate
   // the client.
-  const DWORD kFlags =
-      SECURITY_SQOS_PRESENT | SECURITY_ANONYMOUS | FILE_FLAG_OVERLAPPED;
+  DWORD kFlags = SECURITY_SQOS_PRESENT | SECURITY_ANONYMOUS;
+  if (!client_is_blocking)
+    kFlags |= FILE_FLAG_OVERLAPPED;
   // Allow the handle to be inherited by child processes.
   SECURITY_ATTRIBUTES security_attributes = {
       sizeof(SECURITY_ATTRIBUTES), nullptr, TRUE};
   client_handle_.reset(
       PlatformHandle(CreateFileW(pipe_name.c_str(), kDesiredAccess,
                                  0,  // No sharing.
                                  &security_attributes, OPEN_EXISTING, kFlags,
                                  nullptr)));  // No template file.
   PCHECK(client_handle_.is_valid());
 
   // Since a client has connected, ConnectNamedPipe() should return zero and
   // GetLastError() should return ERROR_PIPE_CONNECTED.
   CHECK(!ConnectNamedPipe(server_handle_.get().handle, nullptr));
   PCHECK(GetLastError() == ERROR_PIPE_CONNECTED);
 }
 
 // static
 ScopedPlatformHandle PlatformChannelPair::PassClientHandleFromParentProcess(
     const base::CommandLine& command_line) {
   std::string client_handle_string =
       command_line.GetSwitchValueASCII(kMojoPlatformChannelHandleSwitch);
+  return PassClientHandleFromParentProcessFromString(client_handle_string);
+}
 
+ScopedPlatformHandle
+PlatformChannelPair::PassClientHandleFromParentProcessFromString(
+    const std::string& value) {
   int client_handle_value = 0;
-  if (client_handle_string.empty() ||
-      !base::StringToInt(client_handle_string, &client_handle_value)) {
+  if (value.empty() ||
+      !base::StringToInt(value, &client_handle_value)) {
     LOG(ERROR) << "Missing or invalid --" << kMojoPlatformChannelHandleSwitch;
     return ScopedPlatformHandle();
   }
 
   return ScopedPlatformHandle(
       PlatformHandle(LongToHandle(client_handle_value)));
 }
 
 void PlatformChannelPair::PrepareToPassClientHandleToChildProcess(
     base::CommandLine* command_line,
     base::HandlesToInheritVector* handle_passing_info) const {
   DCHECK(command_line);
-  DCHECK(handle_passing_info);
-  DCHECK(client_handle_.is_valid());
-
-  if (base::win::GetVersion() >= base::win::VERSION_VISTA)
-    handle_passing_info->push_back(client_handle_.get().handle);
 
   // Log a warning if the command line already has the switch, but "clobber" it
   // anyway, since it's reasonably likely that all the switches were just copied
   // from the parent.
   LOG_IF(WARNING, command_line->HasSwitch(kMojoPlatformChannelHandleSwitch))
       << "Child command line already has switch --"
       << kMojoPlatformChannelHandleSwitch << "="
       << command_line->GetSwitchValueASCII(kMojoPlatformChannelHandleSwitch);
   // (Any existing switch won't actually be removed from the command line, but
   // the last one appended takes precedence.)
   command_line->AppendSwitchASCII(
       kMojoPlatformChannelHandleSwitch,
-      base::IntToString(HandleToLong(client_handle_.get().handle)));
+      PrepareToPassClientHandleToChildProcessAsString(handle_passing_info));
+}
+
+std::string
+PlatformChannelPair::PrepareToPassClientHandleToChildProcessAsString(
+    HandlePassingInformation* handle_passing_info) const {
+  DCHECK(handle_passing_info);
+  DCHECK(client_handle_.is_valid());
+
+  if (base::win::GetVersion() >= base::win::VERSION_VISTA)
+    handle_passing_info->push_back(client_handle_.get().handle);
+
+  return base::IntToString(HandleToLong(client_handle_.get().handle));
 }
 
 }  // namespace edk
 }  // namespace mojo