The Tor Browser: widget/cocoa/WidgetTraceEvent.mm@ac0c01689b40

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     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 <Cocoa/Cocoa.h>

     6 #include "CustomCocoaEvents.h"

     7 #include <Foundation/NSAutoreleasePool.h>

     8 #include <mozilla/CondVar.h>

     9 #include <mozilla/Mutex.h>

    10 #include "mozilla/WidgetTraceEvent.h"

    12 using mozilla::CondVar;

    13 using mozilla::Mutex;

    14 using mozilla::MutexAutoLock;

    16 namespace {

    18 Mutex* sMutex = NULL;

    19 CondVar* sCondVar = NULL;

    20 bool sTracerProcessed = false;

    22 }

    24 namespace mozilla {

    26 bool InitWidgetTracing()

    27 {

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

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

    30   return sMutex && sCondVar;

    31 }

    33 void CleanUpWidgetTracing()

    34 {

    35   delete sMutex;

    36   delete sCondVar;

    37   sMutex = NULL;

    38   sCondVar = NULL;

    39 }

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

    42 void SignalTracerThread()

    43 {

    44   if (!sMutex || !sCondVar)

    45     return;

    46   MutexAutoLock lock(*sMutex);

    47   if (!sTracerProcessed) {

    48     sTracerProcessed = true;

    49     sCondVar->Notify();

    50   }

    51 }

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

    54 bool FireAndWaitForTracerEvent()

    55 {

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

    57   NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];

    58   MutexAutoLock lock(*sMutex);

    59   if (sTracerProcessed) {

    60     // Things are out of sync. This is likely because we're in

    61     // the middle of shutting down. Just return false and hope the

    62     // tracer thread is quitting anyway.

    63     return false;

    64   }

    66   // Post an application-defined event to the main thread's event queue

    67   // and wait for it to get processed.

    68   [NSApp postEvent:[NSEvent otherEventWithType:NSApplicationDefined

    69                                       location:NSMakePoint(0,0)

    70                                  modifierFlags:0

    71                                      timestamp:0

    72                                   windowNumber:0

    73                                        context:NULL

    74                                        subtype:kEventSubtypeTrace

    75                                          data1:0

    76                                          data2:0]

    77              atStart:NO];

    78   while (!sTracerProcessed)

    79     sCondVar->Wait();

    80   sTracerProcessed = false;

    81   [pool release];

    82   return true;

    83 }

    85 }  // namespace mozilla

The Tor Browser / file revision

widget/cocoa/WidgetTraceEvent.mm@ac0c01689b40

widget/cocoa/WidgetTraceEvent.mm