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-rw-r--r--widget/windows/WidgetTraceEvent.cpp119
1 files changed, 119 insertions, 0 deletions
diff --git a/widget/windows/WidgetTraceEvent.cpp b/widget/windows/WidgetTraceEvent.cpp
new file mode 100644
index 0000000000..4509791d59
--- /dev/null
+++ b/widget/windows/WidgetTraceEvent.cpp
@@ -0,0 +1,119 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Windows widget support for event loop instrumentation.
+ * See toolkit/xre/EventTracer.cpp for more details.
+ */
+
+#include <stdio.h>
+#include <windows.h>
+
+#include "mozilla/RefPtr.h"
+#include "mozilla/WidgetTraceEvent.h"
+#include "nsAppShellCID.h"
+#include "nsComponentManagerUtils.h"
+#include "nsCOMPtr.h"
+#include "nsIAppShellService.h"
+#include "nsIBaseWindow.h"
+#include "nsIDocShell.h"
+#include "nsISupportsImpl.h"
+#include "nsIWidget.h"
+#include "nsIAppWindow.h"
+#include "nsServiceManagerUtils.h"
+#include "nsThreadUtils.h"
+#include "nsWindowDefs.h"
+
+namespace {
+
+// Used for signaling the background thread from the main thread.
+HANDLE sEventHandle = nullptr;
+
+// We need a runnable in order to find the hidden window on the main
+// thread.
+class HWNDGetter : public mozilla::Runnable {
+ public:
+ HWNDGetter() : Runnable("HWNDGetter"), hidden_window_hwnd(nullptr) {}
+
+ HWND hidden_window_hwnd;
+
+ NS_IMETHOD Run() override {
+ // Jump through some hoops to locate the hidden window.
+ nsCOMPtr<nsIAppShellService> appShell(
+ do_GetService(NS_APPSHELLSERVICE_CONTRACTID));
+ nsCOMPtr<nsIAppWindow> hiddenWindow;
+
+ nsresult rv = appShell->GetHiddenWindow(getter_AddRefs(hiddenWindow));
+ if (NS_FAILED(rv)) {
+ return rv;
+ }
+
+ nsCOMPtr<nsIDocShell> docShell;
+ rv = hiddenWindow->GetDocShell(getter_AddRefs(docShell));
+ if (NS_FAILED(rv) || !docShell) {
+ return rv;
+ }
+
+ nsCOMPtr<nsIBaseWindow> baseWindow(do_QueryInterface(docShell));
+
+ if (!baseWindow) return NS_ERROR_FAILURE;
+
+ nsCOMPtr<nsIWidget> widget;
+ baseWindow->GetMainWidget(getter_AddRefs(widget));
+
+ if (!widget) return NS_ERROR_FAILURE;
+
+ hidden_window_hwnd = (HWND)widget->GetNativeData(NS_NATIVE_WINDOW);
+
+ return NS_OK;
+ }
+};
+
+HWND GetHiddenWindowHWND() {
+ // Need to dispatch this to the main thread because plenty of
+ // the things it wants to access are main-thread-only.
+ RefPtr<HWNDGetter> getter = new HWNDGetter();
+ NS_DispatchToMainThread(getter, NS_DISPATCH_SYNC);
+ return getter->hidden_window_hwnd;
+}
+
+} // namespace
+
+namespace mozilla {
+
+bool InitWidgetTracing() {
+ sEventHandle = CreateEventW(nullptr, FALSE, FALSE, nullptr);
+ return sEventHandle != nullptr;
+}
+
+void CleanUpWidgetTracing() {
+ CloseHandle(sEventHandle);
+ sEventHandle = nullptr;
+}
+
+// This function is called from the main (UI) thread.
+void SignalTracerThread() {
+ if (sEventHandle != nullptr) SetEvent(sEventHandle);
+}
+
+// This function is called from the background tracer thread.
+bool FireAndWaitForTracerEvent() {
+ MOZ_ASSERT(sEventHandle, "Tracing not initialized!");
+
+ // First, try to find the hidden window.
+ static HWND hidden_window = nullptr;
+ if (hidden_window == nullptr) {
+ hidden_window = GetHiddenWindowHWND();
+ }
+
+ if (hidden_window == nullptr) return false;
+
+ // Post the tracer message into the hidden window's message queue,
+ // and then block until it's processed.
+ PostMessage(hidden_window, MOZ_WM_TRACE, 0, 0);
+ WaitForSingleObject(sEventHandle, INFINITE);
+ return true;
+}
+
+} // namespace mozilla