michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0:  * Windows widget support for event loop instrumentation.
michael@0:  * See toolkit/xre/EventTracer.cpp for more details.
michael@0:  */
michael@0: 
michael@0: #include <stdio.h>
michael@0: #include <windows.h>
michael@0: 
michael@0: #include "mozilla/WidgetTraceEvent.h"
michael@0: #include "nsAppShellCID.h"
michael@0: #include "nsComponentManagerUtils.h"
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsIAppShellService.h"
michael@0: #include "nsIBaseWindow.h"
michael@0: #include "nsIDocShell.h"
michael@0: #include "nsISupportsImpl.h"
michael@0: #include "nsIWidget.h"
michael@0: #include "nsIXULWindow.h"
michael@0: #include "nsAutoPtr.h"
michael@0: #include "nsServiceManagerUtils.h"
michael@0: #include "nsThreadUtils.h"
michael@0: #include "nsWindowDefs.h"
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: // Used for signaling the background thread from the main thread.
michael@0: HANDLE sEventHandle = nullptr;
michael@0: 
michael@0: // We need a runnable in order to find the hidden window on the main
michael@0: // thread.
michael@0: class HWNDGetter : public nsRunnable {
michael@0: public:
michael@0:   HWNDGetter() : hidden_window_hwnd(nullptr) {
michael@0:     MOZ_COUNT_CTOR(HWNDGetter);
michael@0:   }
michael@0:   ~HWNDGetter() {
michael@0:     MOZ_COUNT_DTOR(HWNDGetter);
michael@0:   }
michael@0: 
michael@0:   HWND hidden_window_hwnd;
michael@0: 
michael@0:   NS_IMETHOD Run() {
michael@0:     // Jump through some hoops to locate the hidden window.
michael@0:     nsCOMPtr<nsIAppShellService> appShell(do_GetService(NS_APPSHELLSERVICE_CONTRACTID));
michael@0:     nsCOMPtr<nsIXULWindow> hiddenWindow;
michael@0: 
michael@0:     nsresult rv = appShell->GetHiddenWindow(getter_AddRefs(hiddenWindow));
michael@0:     if (NS_FAILED(rv)) {
michael@0:       return rv;
michael@0:     }
michael@0: 
michael@0:     nsCOMPtr<nsIDocShell> docShell;
michael@0:     rv = hiddenWindow->GetDocShell(getter_AddRefs(docShell));
michael@0:     if (NS_FAILED(rv) || !docShell) {
michael@0:       return rv;
michael@0:     }
michael@0: 
michael@0:     nsCOMPtr<nsIBaseWindow> baseWindow(do_QueryInterface(docShell));
michael@0:     
michael@0:     if (!baseWindow)
michael@0:       return NS_ERROR_FAILURE;
michael@0: 
michael@0:     nsCOMPtr<nsIWidget> widget;
michael@0:     baseWindow->GetMainWidget(getter_AddRefs(widget));
michael@0: 
michael@0:     if (!widget)
michael@0:       return NS_ERROR_FAILURE;
michael@0: 
michael@0:     hidden_window_hwnd = (HWND)widget->GetNativeData(NS_NATIVE_WINDOW);
michael@0: 
michael@0:     return NS_OK;
michael@0:   }
michael@0: };
michael@0: 
michael@0: HWND GetHiddenWindowHWND()
michael@0: {
michael@0:   // Need to dispatch this to the main thread because plenty of
michael@0:   // the things it wants to access are main-thread-only.
michael@0:   nsRefPtr<HWNDGetter> getter = new HWNDGetter();
michael@0:   NS_DispatchToMainThread(getter, NS_DISPATCH_SYNC);
michael@0:   return getter->hidden_window_hwnd;
michael@0: }
michael@0: 
michael@0: } // namespace
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: bool InitWidgetTracing()
michael@0: {
michael@0:   sEventHandle = CreateEvent(nullptr, FALSE, FALSE, nullptr);
michael@0:   return sEventHandle != nullptr;
michael@0: }
michael@0: 
michael@0: void CleanUpWidgetTracing()
michael@0: {
michael@0:   CloseHandle(sEventHandle);
michael@0:   sEventHandle = nullptr;
michael@0: }
michael@0: 
michael@0: // This function is called from the main (UI) thread.
michael@0: void SignalTracerThread()
michael@0: {
michael@0:   if (sEventHandle != nullptr)
michael@0:     SetEvent(sEventHandle);
michael@0: }
michael@0: 
michael@0: // This function is called from the background tracer thread.
michael@0: bool FireAndWaitForTracerEvent()
michael@0: {
michael@0:   NS_ABORT_IF_FALSE(sEventHandle, "Tracing not initialized!");
michael@0: 
michael@0:   // First, try to find the hidden window.
michael@0:   static HWND hidden_window = nullptr;
michael@0:   if (hidden_window == nullptr) {
michael@0:     hidden_window = GetHiddenWindowHWND();
michael@0:   }
michael@0: 
michael@0:   if (hidden_window == nullptr)
michael@0:     return false;
michael@0: 
michael@0:   // Post the tracer message into the hidden window's message queue,
michael@0:   // and then block until it's processed.
michael@0:   PostMessage(hidden_window, MOZ_WM_TRACE, 0, 0);
michael@0:   WaitForSingleObject(sEventHandle, INFINITE);
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: }  // namespace mozilla