Backport (2-0-x) - Remove the race condition between new process creation and context release (#12361)

* Remove the race condition between new process creation and old process releasing remote context

Previously there was a race condition where the getId() method would return the new context ID even
though the release was for the old context.  This changes it to send the "initial" context ID with
the release message to ensure there is no race.

* fetch context ID from remote in sandbox mode

atom/browser/api/atom_api_web_contents.cc

@@ -1014,13 +1014,17 @@ void WebContents::NavigationEntryCommitted(
        details.is_same_document, details.did_replace_entry);
 }
 
-int64_t WebContents::GetID() const {
-  int64_t process_id = web_contents()->GetRenderProcessHost()->GetID();
-  int64_t routing_id = web_contents()->GetRenderViewHost()->GetRoutingID();
+int64_t WebContents::GetIDForContents(content::WebContents* web_contents) {
+  int64_t process_id = web_contents->GetRenderProcessHost()->GetID();
+  int64_t routing_id = web_contents->GetMainFrame()->GetRoutingID();
   int64_t rv = (process_id << 32) + routing_id;
   return rv;
 }
 
+int64_t WebContents::GetID() const {
+  return WebContents::GetIDForContents(web_contents());
+}
+
 int WebContents::GetProcessID() const {
   return web_contents()->GetRenderProcessHost()->GetID();
 }

atom/browser/api/atom_api_web_contents.h

@@ -79,6 +79,8 @@ class WebContents : public mate::TrackableObject<WebContents>,
   static void BuildPrototype(v8::Isolate* isolate,
                              v8::Local<v8::FunctionTemplate> prototype);
 
+  static int64_t GetIDForContents(content::WebContents* web_contents);
+
   // Notifies to destroy any guest web contents before destroying self.
   void DestroyWebContents(bool async);
 

atom/browser/atom_browser_client.cc

@@ -10,6 +10,7 @@
 
 #include "atom/browser/api/atom_api_app.h"
 #include "atom/browser/api/atom_api_protocol.h"
+#include "atom/browser/api/atom_api_web_contents.h"
 #include "atom/browser/atom_browser_context.h"
 #include "atom/browser/atom_browser_main_parts.h"
 #include "atom/browser/atom_quota_permission_context.h"
@@ -318,6 +319,11 @@ void AtomBrowserClient::AppendExtraCommandLineSwitches(
         web_contents, command_line);
     SessionPreferences::AppendExtraCommandLineSwitches(
         web_contents->GetBrowserContext(), command_line);
+
+    auto context_id = atom::api::WebContents::GetIDForContents(
+      web_contents);
+    command_line->AppendSwitchASCII(switches::kContextId,
+      base::IntToString(context_id));
   }
 }
 

atom/common/options_switches.cc

@@ -178,6 +178,9 @@ const char kAppUserModelId[] = "app-user-model-id";
 // The application path
 const char kAppPath[] = "app-path";
 
+// The context ID for this process
+const char kContextId[] = "context-id";
+
 // The command line switch versions of the options.
 const char kBackgroundColor[]  = "background-color";
 const char kPreloadScript[]    = "preload";

atom/common/options_switches.h

@@ -88,6 +88,7 @@ extern const char kRegisterServiceWorkerSchemes[];
 extern const char kSecureSchemes[];
 extern const char kAppUserModelId[];
 extern const char kAppPath[];
+extern const char kContextId[];
 
 extern const char kBackgroundColor[];
 extern const char kPreloadScript[];

lib/browser/rpc-server.js

@@ -394,8 +394,8 @@ ipcMain.on('ELECTRON_BROWSER_DEREFERENCE', function (event, id) {
   objectsRegistry.remove(event.sender.getId(), id)
 })
 
-ipcMain.on('ELECTRON_BROWSER_CONTEXT_RELEASE', (e) => {
-  objectsRegistry.clear(e.sender.getId())
+ipcMain.on('ELECTRON_BROWSER_CONTEXT_RELEASE', (e, contextId) => {
+  objectsRegistry.clear(contextId)
   e.returnValue = null
 })
 

lib/renderer/api/remote.js

@@ -268,7 +268,7 @@ ipcRenderer.on('ELECTRON_RENDERER_RELEASE_CALLBACK', (event, id) => {
 
 process.on('exit', () => {
   const command = 'ELECTRON_BROWSER_CONTEXT_RELEASE'
-  ipcRenderer.sendSync(command)
+  ipcRenderer.sendSync(command, initialContext)
 })
 
 exports.require = (module) => {
@@ -295,6 +295,15 @@ exports.getCurrentWebContents = () => {
   return metaToValue(ipcRenderer.sendSync('ELECTRON_BROWSER_CURRENT_WEB_CONTENTS'))
 }
 
+const CONTEXT_ARG = '--context-id='
+let initialContext = process.argv.find(arg => arg.startsWith(CONTEXT_ARG))
+if (initialContext) {
+  initialContext = parseInt(initialContext.substr(CONTEXT_ARG.length), 10)
+} else {
+  // In sandbox we need to pull this from remote
+  initialContext = exports.getCurrentWebContents().getId()
+}
+
 // Get a global object in browser.
 exports.getGlobal = (name) => {
   const command = 'ELECTRON_BROWSER_GLOBAL'