xpcom/build/XPCOMInit.cpp
author Mike Hommey <mh+mozilla@glandium.org>
Fri, 05 Apr 2019 02:30:56 +0000
changeset 468491 60669a841a87644ba9b2f4d9f17f225e2eca0980
parent 467020 7de6e431f1ae32cacc2b5d4aea1c47bf7900c4c4
child 468661 8f70ba445346be2652ea151291dd3f34b43930b0
permissions -rw-r--r--
Bug 1541792 - Replace linker magic with manual component registration. r=froydnj Before bug 938437, we had a rather large and error-prone nsStaticXULComponents.cpp used to register all modules. That was replaced with clever use of the linker, which allowed to avoid the mess that maintaining that file was. Fast forward to now, where after bug 1524687 and other work that preceded it, we have a much smaller number of remaining static xpcom components, registered via this linker hack, and don't expect to add any new ones. The list should eventually go down to zero. Within that context, it seems to be the right time to get rid of the magic, and with it the problems it causes on its own. Some of those components could probably be trivially be converted to static registration via .conf files, but I didn't want to deal with the possible need to increase the number of dummy modules in XPCOMInit.cpp. They can still be converted as a followup. Differential Revision: https://phabricator.services.mozilla.com/D26076

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */

#include "XPCOMModule.h"

#include "base/basictypes.h"

#include "mozilla/Atomics.h"
#include "mozilla/Poison.h"
#include "mozilla/RemoteDecoderManagerChild.h"
#include "mozilla/SharedThreadPool.h"
#include "mozilla/VideoDecoderManagerChild.h"
#include "mozilla/XPCOM.h"
#include "mozJSComponentLoader.h"
#include "nsXULAppAPI.h"

#ifndef ANDROID
#  include "nsTerminator.h"
#endif

#include "nsXPCOMPrivate.h"
#include "nsXPCOMCIDInternal.h"

#include "mozilla/layers/ImageBridgeChild.h"
#include "mozilla/layers/CompositorBridgeParent.h"

#include "prlink.h"

#include "nsCycleCollector.h"
#include "nsObserverService.h"

#include "nsDebugImpl.h"
#include "nsSystemInfo.h"

#include "nsINIParserImpl.h"

#include "nsComponentManager.h"
#include "nsCategoryManagerUtils.h"
#include "nsIServiceManager.h"

#include "nsThreadManager.h"
#include "nsThreadPool.h"

#include "nsTimerImpl.h"
#include "TimerThread.h"

#include "nsThread.h"
#include "nsVersionComparatorImpl.h"

#include "nsIFile.h"
#include "nsLocalFile.h"
#include "nsDirectoryService.h"
#include "nsDirectoryServiceDefs.h"
#include "nsCategoryManager.h"
#include "nsICategoryManager.h"
#include "nsMultiplexInputStream.h"

#include "nsAtomTable.h"
#include "nsISupportsImpl.h"

#include "nsSystemInfo.h"
#include "nsMemoryReporterManager.h"
#include "nsMessageLoop.h"
#include "nss.h"
#include "ssl.h"

#include <locale.h>
#include "mozilla/Services.h"
#include "mozilla/Omnijar.h"
#include "mozilla/ScriptPreloader.h"
#include "mozilla/SystemGroup.h"
#include "mozilla/Telemetry.h"
#include "mozilla/BackgroundHangMonitor.h"

#include "mozilla/PoisonIOInterposer.h"
#include "mozilla/LateWriteChecks.h"

#include "mozilla/scache/StartupCache.h"

#include "base/at_exit.h"
#include "base/command_line.h"
#include "base/message_loop.h"

#include "mozilla/ipc/BrowserProcessSubThread.h"
#include "mozilla/AvailableMemoryTracker.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/CountingAllocatorBase.h"
#include "mozilla/UniquePtr.h"

#include "mozilla/ipc/GeckoChildProcessHost.h"

#include "ogg/ogg.h"

#include "GeckoProfiler.h"

#include "jsapi.h"
#include "js/Initialization.h"

#include "gfxPlatform.h"

using namespace mozilla;
using base::AtExitManager;
using mozilla::ipc::BrowserProcessSubThread;

// From toolkit/library/rust/lib.rs
extern "C" void GkRust_Init();
extern "C" void GkRust_Shutdown();

namespace {

static AtExitManager* sExitManager;
static MessageLoop* sMessageLoop;
static bool sCommandLineWasInitialized;
static BrowserProcessSubThread* sIOThread;
static BackgroundHangMonitor* sMainHangMonitor;

} /* anonymous namespace */

// Registry Factory creation function defined in nsRegistry.cpp
// We hook into this function locally to create and register the registry
// Since noone outside xpcom needs to know about this and nsRegistry.cpp
// does not have a local include file, we are putting this definition
// here rather than in nsIRegistry.h
extern nsresult NS_RegistryGetFactory(nsIFactory** aFactory);
extern nsresult NS_CategoryManagerGetFactory(nsIFactory**);

#ifdef XP_WIN
extern nsresult CreateAnonTempFileRemover();
#endif

nsresult nsThreadManagerGetSingleton(nsISupports* aOuter, const nsIID& aIID,
                                     void** aInstancePtr) {
  NS_ASSERTION(aInstancePtr, "null outptr");
  if (NS_WARN_IF(aOuter)) {
    return NS_ERROR_NO_AGGREGATION;
  }

  return nsThreadManager::get().QueryInterface(aIID, aInstancePtr);
}

nsresult nsLocalFileConstructor(nsISupports* aOuter, const nsIID& aIID,
                                void** aInstancePtr) {
  return nsLocalFile::nsLocalFileConstructor(aOuter, aIID, aInstancePtr);
}

nsComponentManagerImpl* nsComponentManagerImpl::gComponentManager = nullptr;
bool gXPCOMShuttingDown = false;
bool gXPCOMThreadsShutDown = false;
char16_t* gGREBinPath = nullptr;

static NS_DEFINE_CID(kINIParserFactoryCID, NS_INIPARSERFACTORY_CID);

static already_AddRefed<nsIFactory> CreateINIParserFactory(
    const mozilla::Module& aModule, const mozilla::Module::CIDEntry& aEntry) {
  nsCOMPtr<nsIFactory> f = new nsINIParserFactory();
  return f.forget();
}

const mozilla::Module::CIDEntry kXPCOMCIDEntries[] = {
    {&kINIParserFactoryCID, false, CreateINIParserFactory}, {nullptr}};

const mozilla::Module::ContractIDEntry kXPCOMContracts[] = {
    {NS_INIPARSERFACTORY_CONTRACTID, &kINIParserFactoryCID}, {nullptr}};

const mozilla::Module kXPCOMModule = {
    mozilla::Module::kVersion,
    kXPCOMCIDEntries,
    kXPCOMContracts,
    nullptr,
    nullptr,
    nullptr,
    nullptr,
    Module::ALLOW_IN_GPU_VR_AND_SOCKET_PROCESS};

// gDebug will be freed during shutdown.
static nsIDebug2* gDebug = nullptr;

EXPORT_XPCOM_API(nsresult)
NS_GetDebug(nsIDebug2** aResult) {
  return nsDebugImpl::Create(nullptr, NS_GET_IID(nsIDebug2), (void**)aResult);
}

class ICUReporter final : public nsIMemoryReporter,
                          public CountingAllocatorBase<ICUReporter> {
 public:
  NS_DECL_ISUPPORTS

  static void* Alloc(const void*, size_t aSize) {
    return CountingMalloc(aSize);
  }

  static void* Realloc(const void*, void* aPtr, size_t aSize) {
    return CountingRealloc(aPtr, aSize);
  }

  static void Free(const void*, void* aPtr) { return CountingFree(aPtr); }

 private:
  NS_IMETHOD
  CollectReports(nsIHandleReportCallback* aHandleReport, nsISupports* aData,
                 bool aAnonymize) override {
    MOZ_COLLECT_REPORT(
        "explicit/icu", KIND_HEAP, UNITS_BYTES, MemoryAllocated(),
        "Memory used by ICU, a Unicode and globalization support library.");

    return NS_OK;
  }

  ~ICUReporter() {}
};

NS_IMPL_ISUPPORTS(ICUReporter, nsIMemoryReporter)

/* static */ template <>
CountingAllocatorBase<ICUReporter>::AmountType
    CountingAllocatorBase<ICUReporter>::sAmount(0);

class OggReporter final : public nsIMemoryReporter,
                          public CountingAllocatorBase<OggReporter> {
 public:
  NS_DECL_ISUPPORTS

 private:
  NS_IMETHOD
  CollectReports(nsIHandleReportCallback* aHandleReport, nsISupports* aData,
                 bool aAnonymize) override {
    MOZ_COLLECT_REPORT(
        "explicit/media/libogg", KIND_HEAP, UNITS_BYTES, MemoryAllocated(),
        "Memory allocated through libogg for Ogg, Theora, and related media "
        "files.");

    return NS_OK;
  }

  ~OggReporter() {}
};

NS_IMPL_ISUPPORTS(OggReporter, nsIMemoryReporter)

/* static */ template <>
CountingAllocatorBase<OggReporter>::AmountType
    CountingAllocatorBase<OggReporter>::sAmount(0);

static bool sInitializedJS = false;

// Note that on OSX, aBinDirectory will point to .app/Contents/Resources/browser
EXPORT_XPCOM_API(nsresult)
NS_InitXPCOM(nsIServiceManager** aResult, nsIFile* aBinDirectory,
             nsIDirectoryServiceProvider* aAppFileLocationProvider) {
  static bool sInitialized = false;
  if (sInitialized) {
    return NS_ERROR_FAILURE;
  }

  sInitialized = true;

  mozPoisonValueInit();

  NS_LogInit();

  NS_InitAtomTable();

  // We don't have the arguments by hand here.  If logging has already been
  // initialized by a previous call to LogModule::Init with the arguments
  // passed, passing (0, nullptr) is alright here.
  mozilla::LogModule::Init(0, nullptr);

  GkRust_Init();

  nsresult rv = NS_OK;

  // We are not shutting down
  gXPCOMShuttingDown = false;

#ifdef XP_UNIX
  // Discover the current value of the umask, and save it where
  // nsSystemInfo::Init can retrieve it when necessary.  There is no way
  // to read the umask without changing it, and the setting is process-
  // global, so this must be done while we are still single-threaded; the
  // nsSystemInfo object is typically created much later, when some piece
  // of chrome JS wants it.  The system call is specified as unable to fail.
  nsSystemInfo::gUserUmask = ::umask(0777);
  ::umask(nsSystemInfo::gUserUmask);
#endif

  // Set up chromium libs
  NS_ASSERTION(!sExitManager && !sMessageLoop, "Bad logic!");

  if (!AtExitManager::AlreadyRegistered()) {
    sExitManager = new AtExitManager();
  }

  MessageLoop* messageLoop = MessageLoop::current();
  if (!messageLoop) {
    sMessageLoop = new MessageLoopForUI(MessageLoop::TYPE_MOZILLA_PARENT);
    sMessageLoop->set_thread_name("Gecko");
    // Set experimental values for main thread hangs:
    // 128ms for transient hangs and 8192ms for permanent hangs
    sMessageLoop->set_hang_timeouts(128, 8192);
  } else if (messageLoop->type() == MessageLoop::TYPE_MOZILLA_CHILD) {
    messageLoop->set_thread_name("Gecko_Child");
    messageLoop->set_hang_timeouts(128, 8192);
  }

  if (XRE_IsParentProcess() &&
      !BrowserProcessSubThread::GetMessageLoop(BrowserProcessSubThread::IO)) {
    UniquePtr<BrowserProcessSubThread> ioThread =
        MakeUnique<BrowserProcessSubThread>(BrowserProcessSubThread::IO);

    base::Thread::Options options;
    options.message_loop_type = MessageLoop::TYPE_IO;
    if (NS_WARN_IF(!ioThread->StartWithOptions(options))) {
      return NS_ERROR_FAILURE;
    }

    sIOThread = ioThread.release();
  }

  // Establish the main thread here.
  rv = nsThreadManager::get().Init();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  // Init the SystemGroup for dispatching main thread runnables.
  SystemGroup::InitStatic();

  // Set up the timer globals/timer thread
  rv = nsTimerImpl::Startup();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

#ifndef ANDROID
  // If the locale hasn't already been setup by our embedder,
  // get us out of the "C" locale and into the system
  if (strcmp(setlocale(LC_ALL, nullptr), "C") == 0) {
    setlocale(LC_ALL, "");
  }
#endif

  nsDirectoryService::RealInit();

  bool value;

  if (aBinDirectory) {
    rv = aBinDirectory->IsDirectory(&value);

    if (NS_SUCCEEDED(rv) && value) {
      nsDirectoryService::gService->Set(NS_XPCOM_INIT_CURRENT_PROCESS_DIR,
                                        aBinDirectory);
    }
  }

  if (aAppFileLocationProvider) {
    rv = nsDirectoryService::gService->RegisterProvider(
        aAppFileLocationProvider);
    if (NS_FAILED(rv)) {
      return rv;
    }
  }

  nsCOMPtr<nsIFile> xpcomLib;
  nsDirectoryService::gService->Get(NS_GRE_BIN_DIR, NS_GET_IID(nsIFile),
                                    getter_AddRefs(xpcomLib));
  MOZ_ASSERT(xpcomLib);

  // set gGREBinPath
  nsAutoString path;
  xpcomLib->GetPath(path);
  gGREBinPath = ToNewUnicode(path);

  xpcomLib->AppendNative(nsDependentCString(XPCOM_DLL));
  nsDirectoryService::gService->Set(NS_XPCOM_LIBRARY_FILE, xpcomLib);

  if (!mozilla::Omnijar::IsInitialized()) {
    mozilla::Omnijar::Init();
  }

  if ((sCommandLineWasInitialized = !CommandLine::IsInitialized())) {
#ifdef OS_WIN
    CommandLine::Init(0, nullptr);
#else
    nsCOMPtr<nsIFile> binaryFile;
    nsDirectoryService::gService->Get(NS_XPCOM_CURRENT_PROCESS_DIR,
                                      NS_GET_IID(nsIFile),
                                      getter_AddRefs(binaryFile));
    if (NS_WARN_IF(!binaryFile)) {
      return NS_ERROR_FAILURE;
    }

    rv = binaryFile->AppendNative(NS_LITERAL_CSTRING("nonexistent-executable"));
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    nsCString binaryPath;
    rv = binaryFile->GetNativePath(binaryPath);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }

    static char const* const argv = {strdup(binaryPath.get())};
    CommandLine::Init(1, &argv);
#endif
  }

  NS_ASSERTION(nsComponentManagerImpl::gComponentManager == nullptr,
               "CompMgr not null at init");

  // Create the Component/Service Manager
  nsComponentManagerImpl::gComponentManager = new nsComponentManagerImpl();
  NS_ADDREF(nsComponentManagerImpl::gComponentManager);

  // Global cycle collector initialization.
  if (!nsCycleCollector_init()) {
    return NS_ERROR_UNEXPECTED;
  }

  // And start it up for this thread too.
  nsCycleCollector_startup();

  // Register ICU memory functions.  This really shouldn't be necessary: the
  // JS engine should do this on its own inside JS_Init, and memory-reporting
  // code should call a JSAPI function to observe ICU memory usage.  But we
  // can't define the alloc/free functions in the JS engine, because it can't
  // depend on the XPCOM-based memory reporting goop.  So for now, we have
  // this oddness.
  mozilla::SetICUMemoryFunctions();

  // Do the same for libogg.
  ogg_set_mem_functions(
      OggReporter::CountingMalloc, OggReporter::CountingCalloc,
      OggReporter::CountingRealloc, OggReporter::CountingFree);

  // Initialize the JS engine.
  const char* jsInitFailureReason = JS_InitWithFailureDiagnostic();
  if (jsInitFailureReason) {
    MOZ_CRASH_UNSAFE(jsInitFailureReason);
  }
  sInitializedJS = true;

  rv = nsComponentManagerImpl::gComponentManager->Init();
  if (NS_FAILED(rv)) {
    NS_RELEASE(nsComponentManagerImpl::gComponentManager);
    return rv;
  }

  if (aResult) {
    NS_ADDREF(*aResult = nsComponentManagerImpl::gComponentManager);
  }

  // After autoreg, but before we actually instantiate any components,
  // add any services listed in the "xpcom-directory-providers" category
  // to the directory service.
  nsDirectoryService::gService->RegisterCategoryProviders();

  // Init SharedThreadPool (which needs the service manager).
  SharedThreadPool::InitStatics();

  mozilla::ScriptPreloader::GetSingleton();
  mozilla::scache::StartupCache::GetSingleton();
  mozilla::AvailableMemoryTracker::Init();

  // Notify observers of xpcom autoregistration start
  NS_CreateServicesFromCategory(NS_XPCOM_STARTUP_CATEGORY, nullptr,
                                NS_XPCOM_STARTUP_OBSERVER_ID);
#ifdef XP_WIN
  CreateAnonTempFileRemover();
#endif

  // The memory reporter manager is up and running -- register our reporters.
  RegisterStrongMemoryReporter(new ICUReporter());
  RegisterStrongMemoryReporter(new OggReporter());

  mozilla::Telemetry::Init();

  mozilla::BackgroundHangMonitor::Startup();

  const MessageLoop* const loop = MessageLoop::current();
  sMainHangMonitor = new mozilla::BackgroundHangMonitor(
      loop->thread_name().c_str(), loop->transient_hang_timeout(),
      loop->permanent_hang_timeout());

  return NS_OK;
}

EXPORT_XPCOM_API(nsresult)
NS_InitMinimalXPCOM() {
  mozPoisonValueInit();
  NS_SetMainThread();
  mozilla::TimeStamp::Startup();
  NS_LogInit();
  NS_InitAtomTable();

  // We don't have the arguments by hand here.  If logging has already been
  // initialized by a previous call to LogModule::Init with the arguments
  // passed, passing (0, nullptr) is alright here.
  mozilla::LogModule::Init(0, nullptr);

  GkRust_Init();

  nsresult rv = nsThreadManager::get().Init();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  // Init the SystemGroup for dispatching main thread runnables.
  SystemGroup::InitStatic();

  // Set up the timer globals/timer thread.
  rv = nsTimerImpl::Startup();
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }

  // Create the Component/Service Manager
  nsComponentManagerImpl::gComponentManager = new nsComponentManagerImpl();
  NS_ADDREF(nsComponentManagerImpl::gComponentManager);

  rv = nsComponentManagerImpl::gComponentManager->Init();
  if (NS_FAILED(rv)) {
    NS_RELEASE(nsComponentManagerImpl::gComponentManager);
    return rv;
  }

  // Global cycle collector initialization.
  if (!nsCycleCollector_init()) {
    return NS_ERROR_UNEXPECTED;
  }

  SharedThreadPool::InitStatics();
  mozilla::Telemetry::Init();
  mozilla::BackgroundHangMonitor::Startup();

  return NS_OK;
}

//
// NS_ShutdownXPCOM()
//
// The shutdown sequence for xpcom would be
//
// - Notify "xpcom-shutdown" for modules to release primary (root) references
// - Shutdown XPCOM timers
// - Notify "xpcom-shutdown-threads" for thread joins
// - Shutdown the event queues
// - Release the Global Service Manager
//   - Release all service instances held by the global service manager
//   - Release the Global Service Manager itself
// - Release the Component Manager
//   - Release all factories cached by the Component Manager
//   - Notify module loaders to shut down
//   - Unload Libraries
//   - Release Contractid Cache held by Component Manager
//   - Release dll abstraction held by Component Manager
//   - Release the Registry held by Component Manager
//   - Finally, release the component manager itself
//
EXPORT_XPCOM_API(nsresult)
NS_ShutdownXPCOM(nsIServiceManager* aServMgr) {
  return mozilla::ShutdownXPCOM(aServMgr);
}

namespace mozilla {

void SetICUMemoryFunctions() {
  static bool sICUReporterInitialized = false;
  if (!sICUReporterInitialized) {
    if (!JS_SetICUMemoryFunctions(ICUReporter::Alloc, ICUReporter::Realloc,
                                  ICUReporter::Free)) {
      MOZ_CRASH("JS_SetICUMemoryFunctions failed.");
    }
    sICUReporterInitialized = true;
  }
}

nsresult ShutdownXPCOM(nsIServiceManager* aServMgr) {
  // Make sure the hang monitor is enabled for shutdown.
  BackgroundHangMonitor().NotifyActivity();

  if (!NS_IsMainThread()) {
    MOZ_CRASH("Shutdown on wrong thread");
  }

  nsresult rv;

  // Notify observers of xpcom shutting down
  {
    // Block it so that the COMPtr will get deleted before we hit
    // servicemanager shutdown

    nsCOMPtr<nsIThread> thread = do_GetCurrentThread();
    if (NS_WARN_IF(!thread)) {
      return NS_ERROR_UNEXPECTED;
    }

    RefPtr<nsObserverService> observerService;
    CallGetService("@mozilla.org/observer-service;1",
                   (nsObserverService**)getter_AddRefs(observerService));

    if (observerService) {
      mozilla::KillClearOnShutdown(ShutdownPhase::WillShutdown);
      observerService->NotifyObservers(
          nullptr, NS_XPCOM_WILL_SHUTDOWN_OBSERVER_ID, nullptr);

      nsCOMPtr<nsIServiceManager> mgr;
      rv = NS_GetServiceManager(getter_AddRefs(mgr));
      if (NS_SUCCEEDED(rv)) {
        mozilla::KillClearOnShutdown(ShutdownPhase::Shutdown);
        observerService->NotifyObservers(mgr, NS_XPCOM_SHUTDOWN_OBSERVER_ID,
                                         nullptr);
      }

#ifndef ANDROID
      mozilla::XPCOMShutdownNotified();
#endif
    }

    // This must happen after the shutdown of media and widgets, which
    // are triggered by the NS_XPCOM_SHUTDOWN_OBSERVER_ID notification.
    NS_ProcessPendingEvents(thread);
    gfxPlatform::ShutdownLayersIPC();
    mozilla::VideoDecoderManagerChild::Shutdown();
    mozilla::RemoteDecoderManagerChild::Shutdown();

    mozilla::scache::StartupCache::DeleteSingleton();
    if (observerService) {
      mozilla::KillClearOnShutdown(ShutdownPhase::ShutdownThreads);
      observerService->NotifyObservers(
          nullptr, NS_XPCOM_SHUTDOWN_THREADS_OBSERVER_ID, nullptr);
    }

    gXPCOMThreadsShutDown = true;
    NS_ProcessPendingEvents(thread);

    // Shutdown the timer thread and all timers that might still be alive before
    // shutting down the component manager
    nsTimerImpl::Shutdown();

    NS_ProcessPendingEvents(thread);

    // Shutdown all remaining threads.  This method does not return until
    // all threads created using the thread manager (with the exception of
    // the main thread) have exited.
    nsThreadManager::get().Shutdown();

    NS_ProcessPendingEvents(thread);

    BackgroundHangMonitor().NotifyActivity();

    // Late-write checks needs to find the profile directory, so it has to
    // be initialized before mozilla::services::Shutdown or (because of
    // xpcshell tests replacing the service) modules being unloaded.
    mozilla::InitLateWriteChecks();

    if (observerService) {
      mozilla::KillClearOnShutdown(ShutdownPhase::ShutdownLoaders);
      observerService->Shutdown();
    }
  }

  // Free ClearOnShutdown()'ed smart pointers.  This needs to happen *after*
  // we've finished notifying observers of XPCOM shutdown, because shutdown
  // observers themselves might call ClearOnShutdown().
  mozilla::KillClearOnShutdown(ShutdownPhase::ShutdownFinal);

  // XPCOM is officially in shutdown mode NOW
  // Set this only after the observers have been notified as this
  // will cause servicemanager to become inaccessible.
  mozilla::services::Shutdown();

  // We may have AddRef'd for the caller of NS_InitXPCOM, so release it
  // here again:
  NS_IF_RELEASE(aServMgr);

  // Shutdown global servicemanager
  if (nsComponentManagerImpl::gComponentManager) {
    nsComponentManagerImpl::gComponentManager->FreeServices();
  }

  // Release the directory service
  nsDirectoryService::gService = nullptr;

  free(gGREBinPath);
  gGREBinPath = nullptr;

  // FIXME: This can cause harmless writes from sqlite committing
  // log files. We have to ignore them before we can move
  // the mozilla::PoisonWrite call before this point. See bug
  // 834945 for the details.
  mozJSComponentLoader::Unload();

  // Clear the profiler's JS context before cycle collection. The profiler will
  // notify the JS engine that it can let go of any data it's holding on to for
  // profiling purposes.
  PROFILER_CLEAR_JS_CONTEXT();

  bool shutdownCollect;
#ifdef NS_FREE_PERMANENT_DATA
  shutdownCollect = true;
#else
  shutdownCollect = !!PR_GetEnv("MOZ_CC_RUN_DURING_SHUTDOWN");
#endif
  nsCycleCollector_shutdown(shutdownCollect);

  // There can be code trying to refer to global objects during the final cc
  // shutdown. This is the phase for such global objects to correctly release.
  mozilla::KillClearOnShutdown(ShutdownPhase::ShutdownPostLastCycleCollection);

  PROFILER_ADD_MARKER("Shutdown xpcom", OTHER);
  // If we are doing any shutdown checks, poison writes.
  if (gShutdownChecks != SCM_NOTHING) {
#ifdef XP_MACOSX
    mozilla::OnlyReportDirtyWrites();
#endif /* XP_MACOSX */
    mozilla::BeginLateWriteChecks();
  }

  // Shutdown xpcom. This will release all loaders and cause others holding
  // a refcount to the component manager to release it.
  if (nsComponentManagerImpl::gComponentManager) {
    rv = (nsComponentManagerImpl::gComponentManager)->Shutdown();
    NS_ASSERTION(NS_SUCCEEDED(rv), "Component Manager shutdown failed.");
  } else {
    NS_WARNING("Component Manager was never created ...");
  }

  if (sInitializedJS) {
    // Shut down the JS engine.
    JS_ShutDown();
    sInitializedJS = false;
  }

  // After all threads have been joined and the component manager has been shut
  // down, any remaining objects that could be holding NSS resources (should)
  // have been released, so we can safely shut down NSS.
  if (NSS_IsInitialized()) {
    SSL_ClearSessionCache();
    if (NSS_Shutdown() != SECSuccess) {
      // If you're seeing this crash and/or warning, some NSS resources are
      // still in use (see bugs 1417680 and 1230312). Set the environment
      // variable 'MOZ_IGNORE_NSS_SHUTDOWN_LEAKS' to some value to ignore this.
#if defined(DEBUG) && !defined(ANDROID)
      if (!getenv("MOZ_IGNORE_NSS_SHUTDOWN_LEAKS")) {
        MOZ_CRASH("NSS_Shutdown failed");
      } else {
        NS_WARNING("NSS_Shutdown failed");
      }
#else
      NS_WARNING("NSS_Shutdown failed");
#endif
    }
  }

  // Finally, release the component manager last because it unloads the
  // libraries:
  if (nsComponentManagerImpl::gComponentManager) {
    nsrefcnt cnt;
    NS_RELEASE2(nsComponentManagerImpl::gComponentManager, cnt);
    NS_ASSERTION(cnt == 0, "Component Manager being held past XPCOM shutdown.");
  }
  nsComponentManagerImpl::gComponentManager = nullptr;
  nsCategoryManager::Destroy();

  // Shut down SystemGroup for main thread dispatching.
  SystemGroup::Shutdown();

  GkRust_Shutdown();

  NS_ShutdownAtomTable();

  NS_IF_RELEASE(gDebug);

  delete sIOThread;
  sIOThread = nullptr;

  delete sMessageLoop;
  sMessageLoop = nullptr;

  if (sCommandLineWasInitialized) {
    CommandLine::Terminate();
    sCommandLineWasInitialized = false;
  }

  delete sExitManager;
  sExitManager = nullptr;

  Omnijar::CleanUp();

  BackgroundHangMonitor::Shutdown();

  delete sMainHangMonitor;
  sMainHangMonitor = nullptr;

  NS_LogTerm();

  return NS_OK;
}

}  // namespace mozilla