chrome://nacl asserts

chrome/browser/ui/webui/nacl_ui.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 "chrome/browser/ui/webui/nacl_ui.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 22 matching lines @@
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "webkit/plugins/webplugininfo.h"
 
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #endif
 
+using content::BrowserThread;
 using content::PluginService;
 using content::UserMetricsAction;
 using content::WebUIMessageHandler;
 
 namespace {
 
 content::WebUIDataSource* CreateNaClUIHTMLSource() {
   content::WebUIDataSource* source =
       content::WebUIDataSource::Create(chrome::kChromeUINaClHost);
 
   source->SetUseJsonJSFormatV2();
   source->AddLocalizedString("loadingMessage", IDS_NACL_LOADING_MESSAGE);
   source->AddLocalizedString("naclLongTitle", IDS_NACL_TITLE_MESSAGE);
   source->SetJsonPath("strings.js");
   source->AddResourcePath("about_nacl.css", IDR_ABOUT_NACL_CSS);
   source->AddResourcePath("about_nacl.js", IDR_ABOUT_NACL_JS);
   source->SetDefaultResource(IDR_ABOUT_NACL_HTML);
   return source;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 //
 // NaClDOMHandler
 //
 ////////////////////////////////////////////////////////////////////////////////
 
+class NaClDOMHandler;
+
+class NaClDOMHandlerProxy :  public
+      base::RefCountedThreadSafe<NaClDOMHandlerProxy> {
+ public:
+  explicit NaClDOMHandlerProxy(NaClDOMHandler* handler);
+  // A helper to check if PNaCl path exists.
+  // The check is done on the FILE thread.
+  void ValidatePnaclPath();
+
+  void setHandler(NaClDOMHandler* handler);

[jvoung (off chromium), 2013/05/15 21:19:30]

For chromium, I think the style for setters and getters is like:

void set_foo(...) { foo_ = ...; }

so you could make set_handler(...) { ... } here

+
+ private:
+  // A helper callback that receives the result of checking if PNaCl path
+  // exists. It switches back to the UI thread and saves the result.
+  void ValidatePnaclPathCallback(bool is_valid);
+
+  NaClDOMHandler* handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(NaClDOMHandlerProxy);
+};
+
 // The handler for JavaScript messages for the about:flags page.
 class NaClDOMHandler : public WebUIMessageHandler {
  public:
   NaClDOMHandler();
   virtual ~NaClDOMHandler();
 
   // WebUIMessageHandler implementation.
   virtual void RegisterMessages() OVERRIDE;
 
   // Callback for the "requestNaClInfo" message.
   void HandleRequestNaClInfo(const ListValue* args);
 
   // Callback for the NaCl plugin information.
   void OnGotPlugins(const std::vector<webkit::WebPluginInfo>& plugins);
 
+  // A helper callback that receives the result of checking if PNaCl path
+  // exists. It switches back to the UI thread and saves the result.
+  void ValidatePnaclPathCallback(bool is_valid);
+
  private:
   // Called when enough information is gathered to return data back to the page.
   void MaybeRespondToPage();
 
   // Helper for MaybeRespondToPage -- called after enough information
   // is gathered.
   void PopulatePageInformation(DictionaryValue* naclInfo);
 
   // Factory for the creating refs in callbacks.
   base::WeakPtrFactory<NaClDOMHandler> weak_ptr_factory_;
 
   // Whether the page has requested data.
   bool page_has_requested_data_;
 
   // Whether the plugin information is ready.
   bool has_plugin_info_;
 
+  // Whether PNaCl path was validated. PathService can return a path
+  // that does not exists, so it needs to be validated.
+  bool pnacl_path_validated_;
+  bool pnacl_path_exists_;
+
+  // A proxy for handling cross threads messages.
+  scoped_refptr<NaClDOMHandlerProxy> proxy_;
+
   DISALLOW_COPY_AND_ASSIGN(NaClDOMHandler);
 };
 
+NaClDOMHandlerProxy::NaClDOMHandlerProxy(NaClDOMHandler* handler)
+    : handler_(handler) {
+}
+
+void NaClDOMHandlerProxy::ValidatePnaclPath() {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::FILE)) {
+    BrowserThread::PostTask(
+        BrowserThread::FILE, FROM_HERE,
+        base::Bind(&NaClDOMHandlerProxy::ValidatePnaclPath, this));
+    return;
+  }
+
+  bool is_valid = true;
+  base::FilePath pnacl_path;
+  bool got_path = PathService::Get(chrome::DIR_PNACL_COMPONENT, &pnacl_path);
+  // The PathService may return an empty string if PNaCl is not yet installed.
+  // However, do not trust that the path returned by the PathService exists.
+  // Check for existence here.
+  if (!got_path || pnacl_path.empty() || !file_util::PathExists(pnacl_path)) {
+    is_valid = false;
+  }
+  handler_->ValidatePnaclPathCallback(is_valid);

[jvoung (off chromium), 2013/05/15 21:19:30]

Shouldn't this call the proxy's ValidatePnaclPathCallback to switch back to the
UI thread, instead of the handler's?

Actually, is it possible to name those two callbacks differently to reduce this
confusion?  Maybe one of them could be called "DidValidatePnaclPath(...)"
instead?

+}
+
+void NaClDOMHandlerProxy::ValidatePnaclPathCallback(bool is_valid) {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&NaClDOMHandlerProxy::ValidatePnaclPathCallback,
+        this, is_valid));
+    return;
+  }
+
+  handler_->ValidatePnaclPathCallback(is_valid);
+}
+
+void NaClDOMHandlerProxy::setHandler(NaClDOMHandler* handler) {

[jvoung (off chromium), 2013/05/15 21:19:30]

move set_handler inline

+  handler_ = handler;
+}
+
 NaClDOMHandler::NaClDOMHandler()
     : weak_ptr_factory_(this),
       page_has_requested_data_(false),
-      has_plugin_info_(false) {
+      has_plugin_info_(false),
+      pnacl_path_validated_(false),
+      pnacl_path_exists_(false),
+      proxy_(new NaClDOMHandlerProxy(this)) {
   PluginService::GetInstance()->GetPlugins(base::Bind(
       &NaClDOMHandler::OnGotPlugins, weak_ptr_factory_.GetWeakPtr()));
 }
 
 NaClDOMHandler::~NaClDOMHandler() {
+  if (proxy_) {
+    proxy_->setHandler(NULL);
+  }
 }
 
 void NaClDOMHandler::RegisterMessages() {
   web_ui()->RegisterMessageCallback(
       "requestNaClInfo",
       base::Bind(&NaClDOMHandler::HandleRequestNaClInfo,
                  base::Unretained(this)));
 }
 
 // Helper functions for collecting a list of key-value pairs that will
@@ skipping 24 matching lines @@
   MaybeRespondToPage();
 }
 
 void NaClDOMHandler::OnGotPlugins(
     const std::vector<webkit::WebPluginInfo>& plugins) {
   has_plugin_info_ = true;
   MaybeRespondToPage();
 }
 
 void NaClDOMHandler::PopulatePageInformation(DictionaryValue* naclInfo) {
+  DCHECK(pnacl_path_validated_);
   // Store Key-Value pairs of about-information.
   scoped_ptr<ListValue> list(new ListValue());
 
   // Obtain the Chrome version info.
   chrome::VersionInfo version_info;
   AddPair(list.get(),
           l10n_util::GetStringUTF16(IDS_PRODUCT_NAME),
           ASCIIToUTF16(version_info.Version() + " (" +
                        chrome::VersionInfo::GetVersionStringModifier() + ")"));
 
@@ skipping 59 matching lines @@
   }
 
   // Check that commandline flags are enabled.
   ListFlagStatus(list.get(), "Flag '--enable-nacl'", switches::kEnableNaCl);
 
   AddLineBreak(list.get());
 
   // Obtain the version of the PNaCl translator.
   base::FilePath pnacl_path;
   bool got_path = PathService::Get(chrome::DIR_PNACL_COMPONENT, &pnacl_path);
-  // The PathService may return an empty string if PNaCl is not yet installed.
-  // However, do not trust that the path returned by the PathService exists.
-  // Check for existence here.
-  if (!got_path || pnacl_path.empty() || !file_util::PathExists(pnacl_path)) {
+  if (!got_path || pnacl_path.empty() || !pnacl_path_exists_) {
     AddPair(list.get(),
             ASCIIToUTF16("PNaCl translator"),
             ASCIIToUTF16("Not installed"));
   } else {
     AddPair(list.get(),
             ASCIIToUTF16("PNaCl translator path"),
             pnacl_path.LossyDisplayName());
     AddPair(list.get(),
             ASCIIToUTF16("PNaCl translator version"),
             pnacl_path.BaseName().LossyDisplayName());
   }
 
   ListFlagStatus(list.get(), "Flag '--enable-pnacl'", switches::kEnablePnacl);
   // naclInfo will take ownership of list, and clean it up on destruction.
   naclInfo->Set("naclInfo", list.release());
 }
 
+void NaClDOMHandler::ValidatePnaclPathCallback(bool is_valid) {
+  pnacl_path_validated_ = true;
+  pnacl_path_exists_ = is_valid;
+  MaybeRespondToPage();
+}
+
 void NaClDOMHandler::MaybeRespondToPage() {
   // Don't reply until everything is ready.  The page will show a 'loading'
   // message until then.
   if (!page_has_requested_data_ || !has_plugin_info_)
     return;
 
+  if (!pnacl_path_validated_) {
+    DCHECK(proxy_);
+    proxy_->ValidatePnaclPath();
+    return;
+  }
+
   DictionaryValue naclInfo;
   PopulatePageInformation(&naclInfo);
   web_ui()->CallJavascriptFunction("nacl.returnNaClInfo", naclInfo);
 }
 
 }  // namespace
 
 ///////////////////////////////////////////////////////////////////////////////
 //
 // NaClUI
 //
 ///////////////////////////////////////////////////////////////////////////////
 
 NaClUI::NaClUI(content::WebUI* web_ui) : WebUIController(web_ui) {
   content::RecordAction(UserMetricsAction("ViewAboutNaCl"));
 
   web_ui->AddMessageHandler(new NaClDOMHandler());
 
   // Set up the about:nacl source.
   Profile* profile = Profile::FromWebUI(web_ui);
   content::WebUIDataSource::Add(profile, CreateNaClUIHTMLSource());
 }