From 7e88fe107ded6d92ac5d17f467b2a6f0fb81d14d Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Tue, 21 Apr 2015 21:42:49 +0800
Subject: [PATCH] linux: Pass v8 snapshot's fd to child process

---
 brightray/brightray.gypi            |  2 ++
 brightray/browser/browser_client.cc | 36 ++++++++++++++++++++++++++++-
 brightray/browser/browser_client.h  | 12 ++++++++++
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/brightray/brightray.gypi b/brightray/brightray.gypi
index 50f5a09b3bc..b1865de7851 100644
--- a/brightray/brightray.gypi
+++ b/brightray/brightray.gypi
@@ -119,6 +119,8 @@
         'defines': [
           # We are using Release version libchromiumcontent:
           'NDEBUG',
+          # Needed by gin:
+          'V8_USE_EXTERNAL_STARTUP_DATA',
           # From skia_for_chromium_defines.gypi:
           'SK_SUPPORT_LEGACY_GETTOPDEVICE',
           'SK_SUPPORT_LEGACY_BITMAP_CONFIG',
diff --git a/brightray/browser/browser_client.cc b/brightray/browser/browser_client.cc
index b884cdcdbf1..887ad591d5c 100644
--- a/brightray/browser/browser_client.cc
+++ b/brightray/browser/browser_client.cc
@@ -12,7 +12,9 @@
 
 #include "base/base_paths.h"
 #include "base/path_service.h"
+#include "content/public/common/content_descriptors.h"
 #include "content/public/common/url_constants.h"
+#include "gin/public/isolate_holder.h"
 
 namespace brightray {
 
@@ -27,9 +29,14 @@ BrowserClient* BrowserClient::Get() {
 }
 
 BrowserClient::BrowserClient()
-    : browser_main_parts_() {
+    : browser_main_parts_(nullptr) {
   DCHECK(!g_browser_client);
   g_browser_client = this;
+
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  v8_natives_fd_.reset(-1);
+  v8_snapshot_fd_.reset(-1);
+#endif  // OS_POSIX && !OS_MACOSX
 }
 
 BrowserClient::~BrowserClient() {
@@ -86,4 +93,31 @@ content::DevToolsManagerDelegate* BrowserClient::GetDevToolsManagerDelegate() {
   return new DevToolsManagerDelegate;
 }
 
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+void BrowserClient::GetAdditionalMappedFilesForChildProcess(
+    const base::CommandLine& command_line,
+    int child_process_id,
+    content::FileDescriptorInfo* mappings) {
+  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());
+}
+#endif
+
 }  // namespace brightray
diff --git a/brightray/browser/browser_client.h b/brightray/browser/browser_client.h
index fad326e10bc..cd3c0222310 100644
--- a/brightray/browser/browser_client.h
+++ b/brightray/browser/browser_client.h
@@ -46,8 +46,20 @@ class BrowserClient : public content::ContentBrowserClient {
   base::FilePath GetDefaultDownloadDirectory() override;
   content::DevToolsManagerDelegate* GetDevToolsManagerDelegate() override;
 
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  void GetAdditionalMappedFilesForChildProcess(
+      const base::CommandLine& command_line,
+      int child_process_id,
+      content::FileDescriptorInfo* mappings) override;
+#endif
+
   BrowserMainParts* browser_main_parts_;
 
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  base::ScopedFD v8_natives_fd_;
+  base::ScopedFD v8_snapshot_fd_;
+#endif  // OS_POSIX && !OS_MACOSX
+
   DISALLOW_COPY_AND_ASSIGN(BrowserClient);
 };