Verified Commit a8fdd5d3 authored by Jens Stutte's avatar Jens Stutte Committed by ma1
Browse files

Bug 2048795 - Guard access to the GamepadPlatformService singleton by a... 

Bug 2048795 - Guard access to the GamepadPlatformService singleton by a StaticMutex.  a=RyanVM DONTBUILD

Original Revision: https://phabricator.services.mozilla.com/D308034

Differential Revision: https://phabricator.services.mozilla.com/D309819
parent 455196ce

dom/gamepad/GamepadPlatformService.cpp

+11 −3
Original line number Original line Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include "mozilla/dom/GamepadTestChannelParent.h"

#include "mozilla/dom/GamepadTestChannelParent.h"

#include "mozilla/ipc/BackgroundParent.h"

#include "mozilla/ipc/BackgroundParent.h"

#include "mozilla/Mutex.h"

#include "mozilla/Mutex.h"

#include "mozilla/StaticMutex.h"

#include "mozilla/Unused.h"

#include "mozilla/Unused.h"





#include "nsCOMPtr.h"

#include "nsCOMPtr.h"
@@ -22,9 +23,12 @@ namespace mozilla::dom { 




namespace {

namespace {





StaticMutex gGamepadPlatformServiceMutex;



// This is the singleton instance of GamepadPlatformService, can be called

// This is the singleton instance of GamepadPlatformService, can be called

// by both background and monitor thread.

// by both background and monitor thread.

StaticRefPtr<GamepadPlatformService> gGamepadPlatformServiceSingleton;

StaticRefPtr<GamepadPlatformService> gGamepadPlatformServiceSingleton

    MOZ_GUARDED_BY(gGamepadPlatformServiceMutex);





}  // namespace

}  // namespace
@@ -90,6 +94,7 @@ already_AddRefed<GamepadPlatformService> 
GamepadPlatformService::GetParentService() {

GamepadPlatformService::GetParentService() {

  // GamepadPlatformService can only be accessed in parent process

  // GamepadPlatformService can only be accessed in parent process

  MOZ_ASSERT(XRE_IsParentProcess());

  MOZ_ASSERT(XRE_IsParentProcess());

  StaticMutexAutoLock lock(gGamepadPlatformServiceMutex);

  if (!gGamepadPlatformServiceSingleton) {

  if (!gGamepadPlatformServiceSingleton) {

    // Only Background Thread can create new GamepadPlatformService instance.

    // Only Background Thread can create new GamepadPlatformService instance.

    if (IsOnBackgroundThread()) {

    if (IsOnBackgroundThread()) {
@@ -325,11 +330,14 @@ void GamepadPlatformService::MaybeShutdown() { 
    MutexAutoLock autoLock(mMutex);

    MutexAutoLock autoLock(mMutex);

    isChannelParentEmpty = mChannelParents.IsEmpty();

    isChannelParentEmpty = mChannelParents.IsEmpty();

    if (isChannelParentEmpty) {

    if (isChannelParentEmpty) {

      kungFuDeathGrip = gGamepadPlatformServiceSingleton;

      gGamepadPlatformServiceSingleton = nullptr;

      mGamepadAdded.clear();

      mGamepadAdded.clear();

    }

    }

  }

  }

  if (isChannelParentEmpty) {

    StaticMutexAutoLock lock(gGamepadPlatformServiceMutex);

    kungFuDeathGrip = gGamepadPlatformServiceSingleton;

    gGamepadPlatformServiceSingleton = nullptr;

  }

}

}





void GamepadPlatformService::Cleanup() {

void GamepadPlatformService::Cleanup() {