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: #include "mozilla/WidgetTraceEvent.h"
michael@0: 
michael@0: #include <glib.h>
michael@0: #include <mozilla/CondVar.h>
michael@0: #include <mozilla/Mutex.h>
michael@0: #include <stdio.h>
michael@0: 
michael@0: using mozilla::CondVar;
michael@0: using mozilla::Mutex;
michael@0: using mozilla::MutexAutoLock;
michael@0: 
michael@0: namespace {
michael@0: 
michael@0: Mutex* sMutex = nullptr;
michael@0: CondVar* sCondVar = nullptr;
michael@0: bool sTracerProcessed = false;
michael@0: 
michael@0: // This function is called from the main (UI) thread.
michael@0: gboolean TracerCallback(gpointer data)
michael@0: {
michael@0:   mozilla::SignalTracerThread();
michael@0:   return FALSE;
michael@0: }
michael@0: 
michael@0: } // namespace
michael@0: 
michael@0: namespace mozilla {
michael@0: 
michael@0: bool InitWidgetTracing()
michael@0: {
michael@0:   sMutex = new Mutex("Event tracer thread mutex");
michael@0:   sCondVar = new CondVar(*sMutex, "Event tracer thread condvar");
michael@0:   return sMutex && sCondVar;
michael@0: }
michael@0: 
michael@0: void CleanUpWidgetTracing()
michael@0: {
michael@0:   delete sMutex;
michael@0:   delete sCondVar;
michael@0:   sMutex = nullptr;
michael@0:   sCondVar = nullptr;
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(sMutex && sCondVar, "Tracing not initialized!");
michael@0: 
michael@0:   // Send a default-priority idle event through the
michael@0:   // event loop, and wait for it to finish.
michael@0:   MutexAutoLock lock(*sMutex);
michael@0:   NS_ABORT_IF_FALSE(!sTracerProcessed, "Tracer synchronization state is wrong");
michael@0:   g_idle_add_full(G_PRIORITY_DEFAULT,
michael@0:                   TracerCallback,
michael@0:                   nullptr,
michael@0:                   nullptr);
michael@0:   while (!sTracerProcessed)
michael@0:     sCondVar->Wait();
michael@0:   sTracerProcessed = false;
michael@0:   return true;
michael@0: }
michael@0: 
michael@0: void SignalTracerThread()
michael@0: {
michael@0:   if (!sMutex || !sCondVar)
michael@0:     return;
michael@0:   MutexAutoLock lock(*sMutex);
michael@0:   if (!sTracerProcessed) {
michael@0:     sTracerProcessed = true;
michael@0:     sCondVar->Notify();
michael@0:   }
michael@0: }
michael@0: 
michael@0: }  // namespace mozilla