The Tor Browser: widget/gtk/WidgetTraceEvent.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* This Source Code Form is subject to the terms of the Mozilla Public

     2  * License, v. 2.0. If a copy of the MPL was not distributed with this

     3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     5 #include "mozilla/WidgetTraceEvent.h"

     7 #include <glib.h>

     8 #include <mozilla/CondVar.h>

     9 #include <mozilla/Mutex.h>

    10 #include <stdio.h>

    12 using mozilla::CondVar;

    13 using mozilla::Mutex;

    14 using mozilla::MutexAutoLock;

    16 namespace {

    18 Mutex* sMutex = nullptr;

    19 CondVar* sCondVar = nullptr;

    20 bool sTracerProcessed = false;

    22 // This function is called from the main (UI) thread.

    23 gboolean TracerCallback(gpointer data)

    24 {

    25   mozilla::SignalTracerThread();

    26   return FALSE;

    27 }

    29 } // namespace

    31 namespace mozilla {

    33 bool InitWidgetTracing()

    34 {

    35   sMutex = new Mutex("Event tracer thread mutex");

    36   sCondVar = new CondVar(*sMutex, "Event tracer thread condvar");

    37   return sMutex && sCondVar;

    38 }

    40 void CleanUpWidgetTracing()

    41 {

    42   delete sMutex;

    43   delete sCondVar;

    44   sMutex = nullptr;

    45   sCondVar = nullptr;

    46 }

    48 // This function is called from the background tracer thread.

    49 bool FireAndWaitForTracerEvent()

    50 {

    51   NS_ABORT_IF_FALSE(sMutex && sCondVar, "Tracing not initialized!");

    53   // Send a default-priority idle event through the

    54   // event loop, and wait for it to finish.

    55   MutexAutoLock lock(*sMutex);

    56   NS_ABORT_IF_FALSE(!sTracerProcessed, "Tracer synchronization state is wrong");

    57   g_idle_add_full(G_PRIORITY_DEFAULT,

    58                   TracerCallback,

    59                   nullptr,

    60                   nullptr);

    61   while (!sTracerProcessed)

    62     sCondVar->Wait();

    63   sTracerProcessed = false;

    64   return true;

    65 }

    67 void SignalTracerThread()

    68 {

    69   if (!sMutex || !sCondVar)

    70     return;

    71   MutexAutoLock lock(*sMutex);

    72   if (!sTracerProcessed) {

    73     sTracerProcessed = true;

    74     sCondVar->Notify();

    75   }

    76 }

    78 }  // namespace mozilla

The Tor Browser / file revision