libcef:

- Allow execution of CEF using the current application's message loop.
tests/cefclient:
- Support running of the cefclient application using a single message loop via the TEST_SINGLE_THREADED_MESSAGE_LOOP define.

Issue #1, Suggested implementation by: vridosh

git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@13 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

include/cef.h

@@ -39,14 +39,21 @@
 
 // This function should only be called once when the application is started.
 // Create the thread to host the UI message loop.  A return value of true
-// indicates that it succeeded and false indicates that it failed.
+// indicates that it succeeded and false indicates that it failed. Set
-bool CefInitialize();
+// |multi_threaded_message_loop| to true to have the message loop run in
+// a separate thread.  If |multi_threaded_message_loop| is false than
+// the CefDoMessageLoopWork() function must be called from your message loop.
+bool CefInitialize(bool multi_threaded_message_loop);
 
 // This function should only be called once before the application exits.
 // Shut down the thread hosting the UI message loop and destroy any created
 // windows.
 void CefShutdown();
 
+// Perform message loop processing.  Has no affect if the browser UI loop is
+// running in a separate thread.
+void CefDoMessageLoopWork();
+
 
 // Interface defining the the reference count implementation methods. All
 // framework classes must implement the CefBase class.

libcef/context.cc

@@ -10,7 +10,6 @@
 #include "browser_request_context.h"
 #include "../include/cef_nplugin.h"
 
-#include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/icu_util.h"
 #include "base/path_service.h"
@@ -33,7 +32,30 @@ static const char* kStatsFilePrefix = "libcef_";
 static int kStatsFileThreads = 20;
 static int kStatsFileCounters = 200;
 
-bool CefInitialize()
+
+// Class used to process events on the current message loop.
+class CefMessageLoopForUI : public MessageLoopForUI
+{
+  typedef MessageLoopForUI inherited;
+
+public:
+  CefMessageLoopForUI()
+  {
+  }
+
+  virtual bool DoIdleWork() {
+    bool valueToRet = inherited::DoIdleWork();
+    pump_->Quit();
+    return valueToRet;
+  }
+
+  void DoMessageLoopIteration() {
+    Run(NULL);
+  }
+};
+
+
+bool CefInitialize(bool multi_threaded_message_loop)
 {
   // Return true if the context is already initialized
   if(_Context.get())
@@ -42,7 +64,7 @@ bool CefInitialize()
   // Create the new global context object
   _Context = new CefContext();
   // Initialize the glboal context
-  return _Context->Initialize();
+  return _Context->Initialize(multi_threaded_message_loop);
 }
 
 void CefShutdown()
@@ -57,6 +79,13 @@ void CefShutdown()
   _Context = NULL;
 }
 
+void CefDoMessageLoopWork()
+{
+  if(!_Context->RunningOnUIThread())
+    return;
+  ((CefMessageLoopForUI*)CefMessageLoopForUI::current())->DoMessageLoopIteration();
+}
+
 bool CefRegisterPlugin(const struct CefPluginInfo& plugin_info)
 {
   if(!_Context.get())
@@ -124,10 +153,8 @@ StringPiece NetResourceProvider(int key) {
   return GetRawDataResource(::GetModuleHandle(NULL), key);
 }
 
-DWORD WINAPI ThreadHandlerUI(LPVOID lpParam)
+bool CefContext::DoInitialize()
 {
-  CefContext *pContext = static_cast<CefContext*>(lpParam);
-
   HRESULT res;
 
   // Initialize common controls
@@ -142,16 +169,9 @@ DWORD WINAPI ThreadHandlerUI(LPVOID lpParam)
   res = OleInitialize(NULL);
   DCHECK(SUCCEEDED(res));
 
-  // Instantiate the AtExitManager to avoid asserts and possible memory leaks.
-  base::AtExitManager at_exit_manager;
-
   // Initialize the global CommandLine object.
   CommandLine::Init(0, NULL);
 
-  // Instantiate the message loop for this thread.
-  MessageLoopForUI main_message_loop;
-  pContext->SetMessageLoopForUI(&main_message_loop);
-
   // Initializing with a default context, which means no on-disk cookie DB,
   // and no support for directory listings.
   // TODO(cef): Either disable caching or send the cache files to a reasonable
@@ -166,7 +186,7 @@ DWORD WINAPI ThreadHandlerUI(LPVOID lpParam)
   if(!ret) {
     MessageBox(NULL, L"Failed to load the required icudt38 library",
       L"CEF Initialization Error", MB_ICONERROR | MB_OK);
-    return 1;
+    return false;
   }
 
   // Config the network module so it has access to a limited set of resources.
@@ -174,19 +194,17 @@ DWORD WINAPI ThreadHandlerUI(LPVOID lpParam)
 
   // Load and initialize the stats table.  Attempt to construct a somewhat
   // unique name to isolate separate instances from each other.
-  StatsTable *table = new StatsTable(
+  statstable_ = new StatsTable(
       kStatsFilePrefix + Uint64ToString(base::RandUint64()),
       kStatsFileThreads,
       kStatsFileCounters);
-  StatsTable::set_current(table);
+  StatsTable::set_current(statstable_);
 
-  // Notify the context that initialization is complete so that the
+  return true;
-  // Initialize() function can return.
+}
-  pContext->NotifyEvent();
-
-  // Execute the message loop that will run until a quit task is received.
-  MessageLoop::current()->Run();
 
+void CefContext::DoUninitialize()
+{
   // Flush any remaining messages.  This ensures that any accumulated
   // Task objects get destroyed before we exit, which avoids noise in
   // purify leak-test results.
@@ -196,13 +214,35 @@ DWORD WINAPI ThreadHandlerUI(LPVOID lpParam)
     
   // Tear down shared StatsTable; prevents unit_tests from leaking it.
   StatsTable::set_current(NULL);
-  delete table;
+  delete statstable_;
+  statstable_ = NULL;
 
   // Uninitialize COM stuff
   OleUninitialize();
 
   // Uninitialize common controls
   CoUninitialize();
+}
+
+DWORD WINAPI ThreadHandlerUI(LPVOID lpParam)
+{
+  CefContext *pContext = static_cast<CefContext*>(lpParam);
+
+  if (!pContext->DoInitialize()) 
+    return 1;
+
+  // Instantiate the message loop for this thread.
+  MessageLoopForUI main_message_loop;
+  pContext->SetMessageLoopForUI(&main_message_loop);
+
+  // Notify the context that initialization is complete so that the
+  // Initialize() function can return.
+  pContext->NotifyEvent();
+
+  // Execute the message loop that will run until a quit task is received.
+  MessageLoop::current()->Run();
+
+  pContext->DoUninitialize();
 
   return 0;
 }
@@ -222,9 +262,11 @@ CefContext::~CefContext()
 {
   // Just in case CefShutdown() isn't called
   Shutdown();
+
+  DoUninitialize();
 }
 
-bool CefContext::Initialize()
+bool CefContext::Initialize(bool multi_threaded_message_loop)
 {
   bool initialized = false, intransition = false;
   
@@ -294,15 +336,24 @@ bool CefContext::Initialize()
       webprefs_->java_enabled = true;
       webprefs_->allow_scripts_to_close_windows = false;
 
-      // Event that will be used to signal thread setup completion. Start
+      if (multi_threaded_message_loop) {
-      // in non-signaled mode so that the event will block.
+        // Event that will be used to signal thread setup completion. Start
-      heventui_ = CreateEvent(NULL, TRUE, FALSE, NULL);
+        // in non-signaled mode so that the event will block.
-      DCHECK(heventui_ != NULL);
+        heventui_ = CreateEvent(NULL, TRUE, FALSE, NULL);
-      
+        DCHECK(heventui_ != NULL);
-      // Thread that hosts the UI loop
+        
-      hthreadui_ = CreateThread(
+        // Thread that hosts the UI loop
-          NULL, 0, ThreadHandlerUI, this, 0, &idthreadui_);
+        hthreadui_ = CreateThread(
-      DCHECK(hthreadui_ != NULL);
+            NULL, 0, ThreadHandlerUI, this, 0, &idthreadui_);
+        DCHECK(hthreadui_ != NULL);
+      } else {
+        if (!DoInitialize()) {
+          // TODO: Process initialization errors
+        }
+        // Create our own message loop there
+        SetMessageLoopForUI(new CefMessageLoopForUI());
+        idthreadui_ = GetCurrentThreadId();
+      }
       
       initialized = true;
     }
@@ -311,8 +362,10 @@ bool CefContext::Initialize()
   Unlock();
   
   if(initialized) {
-    // Wait for initial UI thread setup to complete
+    if (multi_threaded_message_loop) {
-    WaitForSingleObject(heventui_, INFINITE);
+      // Wait for initial UI thread setup to complete
+      WaitForSingleObject(heventui_, INFINITE);
+    }
 
     Lock();
 

libcef/context.h

@@ -7,6 +7,7 @@
 #define _CONTEXT_H
 
 #include "../include/cef.h"
+#include "base/at_exit.h"
 #include "base/message_loop.h"
 #include "base/gfx/native_widget_types.h"
 #include "webkit/glue/webpreferences.h"
@@ -21,7 +22,7 @@ public:
   CefContext();
   ~CefContext();
 
-  bool Initialize();
+  bool Initialize(bool multi_threaded_message_loop);
   void Shutdown();
 
   MessageLoopForUI* GetMessageLoopForUI() { return messageloopui_; }
@@ -45,10 +46,17 @@ public:
   void UIT_RegisterPlugin(struct CefPluginInfo* plugin_info);
   void UIT_UnregisterPlugin(struct CefPluginInfo* plugin_info);
 
+  bool DoWork();
+  bool DoDelayedWork();
+  bool DoIdleWork();
+
 private:
   void SetMessageLoopForUI(MessageLoopForUI* loop);
   void NotifyEvent();
   
+  bool DoInitialize();
+  void DoUninitialize();
+
 protected:
   HMODULE hinstance_;
   DWORD idthreadui_;
@@ -58,6 +66,10 @@ protected:
   bool in_transition_;
   BrowserList browserlist_;
   WebPreferences* webprefs_;
+  StatsTable* statstable_;
+
+  // Instantiate the AtExitManager to avoid asserts and possible memory leaks.
+  base::AtExitManager at_exit_manager_;
 
   friend DWORD WINAPI ThreadHandlerUI(LPVOID lpParam);
 };

tests/cefclient/cefclient.cpp

@@ -15,6 +15,10 @@
 #define BUTTON_WIDTH 72
 #define URLBAR_HEIGHT  24
 
+// Define this value to run CEF with messages processed using the current
+// application's message loop.
+//#define TEST_SINGLE_THREADED_MESSAGE_LOOP
+
 // Global Variables:
 HINSTANCE hInst;								// current instance
 TCHAR szTitle[MAX_LOADSTRING];					// The title bar text
@@ -31,11 +35,17 @@ int APIENTRY _tWinMain(HINSTANCE hInstance,
                      LPTSTR    lpCmdLine,
                      int       nCmdShow)
 {
-	UNREFERENCED_PARAMETER(hPrevInstance);
+  UNREFERENCED_PARAMETER(hPrevInstance);
-	UNREFERENCED_PARAMETER(lpCmdLine);
+  UNREFERENCED_PARAMETER(lpCmdLine);
 
-  // Initialize the CEF
+#ifdef TEST_SINGLE_THREADED_MESSAGE_LOOP
-  CefInitialize();
+  // Initialize the CEF with messages processed using the current application's
+  // message loop.
+  CefInitialize(false);
+#else
+  // Initialize the CEF with messages processed using a separate UI thread.
+  CefInitialize(true);
+#endif
 
   // Structure providing information about the client plugin.
   CefPluginInfo plugin_info;
@@ -56,31 +66,36 @@ int APIENTRY _tWinMain(HINSTANCE hInstance,
   // Register the internal client plugin
   CefRegisterPlugin(plugin_info);
 
- 	MSG msg;
+  MSG msg;
-	HACCEL hAccelTable;
+  HACCEL hAccelTable;
 
-	// Initialize global strings
+  // Initialize global strings
-	LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
+  LoadString(hInstance, IDS_APP_TITLE, szTitle, MAX_LOADSTRING);
-	LoadString(hInstance, IDC_CEFCLIENT, szWindowClass, MAX_LOADSTRING);
+  LoadString(hInstance, IDC_CEFCLIENT, szWindowClass, MAX_LOADSTRING);
-	MyRegisterClass(hInstance);
+  MyRegisterClass(hInstance);
 
-	// Perform application initialization
+  // Perform application initialization
-	if (!InitInstance (hInstance, nCmdShow))
+  if (!InitInstance (hInstance, nCmdShow))
-	{
+  {
-		return FALSE;
+    return FALSE;
-	}
+  }
 
-	hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_CEFCLIENT));
+  hAccelTable = LoadAccelerators(hInstance, MAKEINTRESOURCE(IDC_CEFCLIENT));
 
-	// Main message loop
+  // Main message loop
-	while (GetMessage(&msg, NULL, 0, 0))
+  while (GetMessage(&msg, NULL, 0, 0))
-	{
+  {
-		if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
+#ifdef TEST_SINGLE_THREADED_MESSAGE_LOOP
-		{
+    // Allow the CEF to do its message loop processing.
-			TranslateMessage(&msg);
+    CefDoMessageLoopWork();
-			DispatchMessage(&msg);
+#endif
-		}
+
-	}
+    if (!TranslateAccelerator(msg.hwnd, hAccelTable, &msg))
+    {
+      TranslateMessage(&msg);
+      DispatchMessage(&msg);
+    }
+  }
 
   // Shut down the CEF
   CefShutdown();