Transfer v8 snapshot files as file descriptors to child processes on Posix

content/shell/browser/shell_content_browser_client.cc

 // Copyright 2013 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/shell/browser/shell_content_browser_client.h"
 
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/files/file.h"
 #include "base/files/file_util.h"
@@ skipping 15 matching lines @@
 #include "content/shell/browser/shell_browser_main_parts.h"
 #include "content/shell/browser/shell_devtools_manager_delegate.h"
 #include "content/shell/browser/shell_net_log.h"
 #include "content/shell/browser/shell_quota_permission_context.h"
 #include "content/shell/browser/shell_resource_dispatcher_host_delegate.h"
 #include "content/shell/browser/shell_web_contents_view_delegate_creator.h"
 #include "content/shell/browser/webkit_test_controller.h"
 #include "content/shell/common/shell_messages.h"
 #include "content/shell/common/shell_switches.h"
 #include "content/shell/common/webkit_test_helpers.h"
+#include "gin/public/isolate_holder.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "url/gurl.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/path_utils.h"
 #include "components/crash/browser/crash_dump_manager_android.h"
 #include "content/shell/android/shell_descriptors.h"
 #endif
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
@@ skipping 74 matching lines @@
 
 ShellContentBrowserClient* ShellContentBrowserClient::Get() {
   return g_browser_client;
 }
 
 void ShellContentBrowserClient::SetSwapProcessesForRedirect(bool swap) {
   g_swap_processes_for_redirect = swap;
 }
 
 ShellContentBrowserClient::ShellContentBrowserClient()
-    : shell_browser_main_parts_(NULL) {
+    :
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+      v8_natives_fd_(-1),
+      v8_snapshot_fd_(-1),
+#endif  // OS_POSIX && !OS_MACOSX
+      shell_browser_main_parts_(NULL) {
   DCHECK(!g_browser_client);
   g_browser_client = this;
 }
 
 ShellContentBrowserClient::~ShellContentBrowserClient() {
   g_browser_client = NULL;
 }
 
 BrowserMainParts* ShellContentBrowserClient::CreateBrowserMainParts(
     const MainFunctionParams& parameters) {
@@ skipping 169 matching lines @@
                                       params.url,
                                       nullptr,
                                       gfx::Size())->web_contents());
 }
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 void ShellContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
     const base::CommandLine& command_line,
     int child_process_id,
     FileDescriptorInfo* mappings) {
+#if defined(V8_USE_EXTERNAL_STARTUP_DATA)
+  if (v8_snapshot_fd_.get() == -1 && v8_natives_fd_.get() == -1) {
+    base::FilePath v8_data_path;
+    PathService::Get(gin::IsolateHolder::kV8SnapshotBasePathKey, &v8_data_path);
+    DCHECK(!v8_data_path.empty());
+
+    int file_flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
+    base::FilePath v8_natives_data_path =
+        v8_data_path.AppendASCII(gin::IsolateHolder::kNativesFileName);
+    base::FilePath v8_snapshot_data_path =
+        v8_data_path.AppendASCII(gin::IsolateHolder::kSnapshotFileName);
+    base::File v8_natives_data_file(v8_natives_data_path, file_flags);
+    base::File v8_snapshot_data_file(v8_snapshot_data_path, file_flags);
+    DCHECK(v8_natives_data_file.IsValid());
+    DCHECK(v8_snapshot_data_file.IsValid());
+    v8_natives_fd_.reset(v8_natives_data_file.TakePlatformFile());
+    v8_snapshot_fd_.reset(v8_snapshot_data_file.TakePlatformFile());
+  }
+  mappings->Share(kV8NativesDataDescriptor, v8_natives_fd_.get());
+  mappings->Share(kV8SnapshotDataDescriptor, v8_snapshot_fd_.get());

[rmcilroy, 2015/02/20 22:53:25]

I'm not keen on the duplication with chrome_content_browser_client here, but
there doesn't seem to be a convenient common class and existing code already
seems to duplicate between these classes.  Let me know if you have an
alternative.

+#endif  // V8_USE_EXTERNAL_STARTUP_DATA
+
 #if defined(OS_ANDROID)
   int flags = base::File::FLAG_OPEN | base::File::FLAG_READ;
   base::FilePath pak_file;
   bool r = PathService::Get(base::DIR_ANDROID_APP_DATA, &pak_file);
   CHECK(r);
   pak_file = pak_file.Append(FILE_PATH_LITERAL("paks"));
   pak_file = pak_file.Append(FILE_PATH_LITERAL("content_shell.pak"));
 
   base::File f(pak_file, flags);
   if (!f.IsValid()) {
@@ skipping 55 matching lines @@
 ShellBrowserContext*
 ShellContentBrowserClient::ShellBrowserContextForBrowserContext(
     BrowserContext* content_browser_context) {
   if (content_browser_context == browser_context())
     return browser_context();
   DCHECK_EQ(content_browser_context, off_the_record_browser_context());
   return off_the_record_browser_context();
 }
 
 }  // namespace content