Pass StatsTable shared memory via global descriptors on Posix rather than using named shared memory.

content/browser/child_process_launcher.cc

 // Copyright (c) 2012 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 "content/browser/child_process_launcher.h"
 
 #include <utility>  // For std::pair.
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 14 matching lines @@
 #include "base/files/file_path.h"
 #include "content/common/sandbox_win.h"
 #include "content/public/common/sandbox_init.h"
 #include "content/public/common/sandboxed_process_launcher_delegate.h"
 #elif defined(OS_MACOSX)
 #include "content/browser/mach_broker_mac.h"
 #elif defined(OS_ANDROID)
 #include "base/android/jni_android.h"
 #include "content/browser/android/child_process_launcher_android.h"
 #elif defined(OS_POSIX)
+#include "base/memory/shared_memory.h"
 #include "base/memory/singleton.h"
 #include "content/browser/renderer_host/render_sandbox_host_linux.h"
 #include "content/browser/zygote_host/zygote_host_impl_linux.h"
 #endif
 
 #if defined(OS_POSIX)
+#include "base/metrics/stats_table.h"
 #include "base/posix/global_descriptors.h"
 #endif
 
 namespace content {
 
 // Having the functionality of ChildProcessLauncher be in an internal
 // ref counted object allows us to automatically terminate the process when the
 // parent class destructs, while still holding on to state that we need.
 class ChildProcessLauncher::Context
     : public base::RefCountedThreadSafe<ChildProcessLauncher::Context> {
@@ skipping 148 matching lines @@
 #elif defined(OS_ANDROID)
     // Android WebView runs in single process, ensure that we never get here
     // when running in single process mode.
     CHECK(!cmd_line->HasSwitch(switches::kSingleProcess));
 
     std::string process_type =
         cmd_line->GetSwitchValueASCII(switches::kProcessType);
     std::vector<FileDescriptorInfo> files_to_register;
     files_to_register.push_back(
         FileDescriptorInfo(kPrimaryIPCChannel,
-                                    base::FileDescriptor(ipcfd, false)));
+                           base::FileDescriptor(ipcfd, false)));
+    base::StatsTable* stats_table = base::StatsTable::current();
+    if (stats_table &&
+        base::SharedMemory::IsHandleValid(
+            stats_table->GetSharedMemoryHandle())) {
+      files_to_register.push_back(
+          FileDescriptorInfo(kStatsTableSharedMemFd,
+                             stats_table->GetSharedMemoryHandle()));
+    }
 
     GetContentClient()->browser()->
         GetAdditionalMappedFilesForChildProcess(*cmd_line, child_process_id,
                                                 &files_to_register);
 
     StartChildProcess(cmd_line->argv(), files_to_register,
         base::Bind(&ChildProcessLauncher::Context::OnChildProcessStarted,
                    this_object, client_thread_id, begin_launch_time));
 
 #elif defined(OS_POSIX)
     base::ProcessHandle handle = base::kNullProcessHandle;
     // We need to close the client end of the IPC channel to reliably detect
     // child termination.
     file_util::ScopedFD ipcfd_closer(&ipcfd);
 
     std::string process_type =
         cmd_line->GetSwitchValueASCII(switches::kProcessType);
     std::vector<FileDescriptorInfo> files_to_register;
     files_to_register.push_back(
         FileDescriptorInfo(kPrimaryIPCChannel,
-                                    base::FileDescriptor(ipcfd, false)));
-
+                           base::FileDescriptor(ipcfd, false)));
+    base::StatsTable* stats_table = base::StatsTable::current();

[jam, 2013/08/25 16:22:25]

we need to have one copy of this code, not two, and also same for lines 235-240
which are also duplicated. up to you whether this is done by combining the
ifdefs for android and posix and adding android ifdefs inside of that, or using
a helper function.

[rmcilroy, 2013/08/27 14:13:06]

Done (combined ifdefs).

+    if (stats_table &&
+        base::SharedMemory::IsHandleValid(
+            stats_table->GetSharedMemoryHandle())) {
+      files_to_register.push_back(
+          FileDescriptorInfo(kStatsTableSharedMemFd,
+                             stats_table->GetSharedMemoryHandle()));
+    }
 #if !defined(OS_MACOSX)
     GetContentClient()->browser()->
         GetAdditionalMappedFilesForChildProcess(*cmd_line, child_process_id,
                                                 &files_to_register);
     if (use_zygote) {
       handle = ZygoteHostImpl::GetInstance()->ForkRequest(cmd_line->argv(),
                                                           files_to_register,
                                                           process_type);
     } else
     // Fall through to the normal posix case below when we're not zygoting.
@@ skipping 251 matching lines @@
           GetHandle(), background));
 }
 
 void ChildProcessLauncher::SetTerminateChildOnShutdown(
   bool terminate_on_shutdown) {
   if (context_.get())
     context_->set_terminate_child_on_shutdown(terminate_on_shutdown);
 }
 
 }  // namespace content