1 files changed, 445 insertions, 0 deletions
diff --git a/xpcom/base/AppShutdown.cpp b/xpcom/base/AppShutdown.cpp
new file mode 100644
index 0000000000..2b34a8edd2
--- /dev/null
+++ b/xpcom/base/AppShutdown.cpp
@@ -0,0 +1,445 @@
+/* -*- 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 "ShutdownPhase.h"
+#ifdef XP_WIN
+#  include <windows.h>
+#  include "mozilla/PreXULSkeletonUI.h"
+#else
+#  include <unistd.h>
+#endif
+
+#include "ProfilerControl.h"
+#include "mozilla/ClearOnShutdown.h"
+#include "mozilla/CmdLineAndEnvUtils.h"
+#include "mozilla/PoisonIOInterposer.h"
+#include "mozilla/Printf.h"
+#include "mozilla/scache/StartupCache.h"
+#include "mozilla/SpinEventLoopUntil.h"
+#include "mozilla/StartupTimeline.h"
+#include "mozilla/StaticPrefs_toolkit.h"
+#include "mozilla/LateWriteChecks.h"
+#include "mozilla/Services.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include "nsAppRunner.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsICertStorage.h"
+#include "nsThreadUtils.h"
+
+#include "AppShutdown.h"
+
+// TODO: understand why on Android we cannot include this and if we should
+#ifndef ANDROID
+#  include "nsTerminator.h"
+#endif
+#include "prenv.h"
+
+#ifdef MOZ_NEW_XULSTORE
+#  include "mozilla/XULStore.h"
+#endif
+
+#ifdef MOZ_BACKGROUNDTASKS
+#  include "mozilla/BackgroundTasks.h"
+#endif
+
+namespace mozilla {
+
+const char* sPhaseObserverKeys[] = {
+    nullptr,                            // NotInShutdown
+    "quit-application",                 // AppShutdownConfirmed
+    "profile-change-net-teardown",      // AppShutdownNetTeardown
+    "profile-change-teardown",          // AppShutdownTeardown
+    "profile-before-change",            // AppShutdown
+    "profile-before-change-qm",         // AppShutdownQM
+    "profile-before-change-telemetry",  // AppShutdownTelemetry
+    "xpcom-will-shutdown",              // XPCOMWillShutdown
+    "xpcom-shutdown",                   // XPCOMShutdown
+    "xpcom-shutdown-threads",           // XPCOMShutdownThreads
+    nullptr,                            // XPCOMShutdownFinal
+    nullptr                             // CCPostLastCycleCollection
+};
+
+static_assert(sizeof(sPhaseObserverKeys) / sizeof(sPhaseObserverKeys[0]) ==
+              (size_t)ShutdownPhase::ShutdownPhase_Length);
+
+const char* sPhaseReadableNames[] = {"NotInShutdown",
+                                     "AppShutdownConfirmed",
+                                     "AppShutdownNetTeardown",
+                                     "AppShutdownTeardown",
+                                     "AppShutdown",
+                                     "AppShutdownQM",
+                                     "AppShutdownTelemetry",
+                                     "XPCOMWillShutdown",
+                                     "XPCOMShutdown",
+                                     "XPCOMShutdownThreads",
+                                     "XPCOMShutdownFinal",
+                                     "CCPostLastCycleCollection"};
+
+static_assert(sizeof(sPhaseReadableNames) / sizeof(sPhaseReadableNames[0]) ==
+              (size_t)ShutdownPhase::ShutdownPhase_Length);
+
+#ifndef ANDROID
+static nsTerminator* sTerminator = nullptr;
+#endif
+
+static ShutdownPhase sFastShutdownPhase = ShutdownPhase::NotInShutdown;
+static ShutdownPhase sLateWriteChecksPhase = ShutdownPhase::NotInShutdown;
+static AppShutdownMode sShutdownMode = AppShutdownMode::Normal;
+static Atomic<ShutdownPhase> sCurrentShutdownPhase(
+    ShutdownPhase::NotInShutdown);
+static int sExitCode = 0;
+
+// These environment variable strings are all deliberately copied and leaked
+// due to requirements of PR_SetEnv and similar.
+static char* sSavedXulAppFile = nullptr;
+#ifdef XP_WIN
+static wchar_t* sSavedProfDEnvVar = nullptr;
+static wchar_t* sSavedProfLDEnvVar = nullptr;
+#else
+static char* sSavedProfDEnvVar = nullptr;
+static char* sSavedProfLDEnvVar = nullptr;
+#endif
+
+ShutdownPhase GetShutdownPhaseFromPrefValue(int32_t aPrefValue) {
+  switch (aPrefValue) {
+    case 1:
+      return ShutdownPhase::CCPostLastCycleCollection;
+    case 2:
+      return ShutdownPhase::XPCOMShutdownThreads;
+    case 3:
+      return ShutdownPhase::XPCOMShutdown;
+      // NOTE: the remaining values from the ShutdownPhase enum will be added
+      // when we're at least reasonably confident that the world won't come
+      // crashing down if we do a fast shutdown at that point.
+  }
+  return ShutdownPhase::NotInShutdown;
+}
+
+ShutdownPhase AppShutdown::GetCurrentShutdownPhase() {
+  return sCurrentShutdownPhase;
+}
+
+bool AppShutdown::IsInOrBeyond(ShutdownPhase aPhase) {
+  return (sCurrentShutdownPhase >= aPhase);
+}
+
+int AppShutdown::GetExitCode() { return sExitCode; }
+
+void AppShutdown::SaveEnvVarsForPotentialRestart() {
+  const char* s = PR_GetEnv("XUL_APP_FILE");
+  if (s) {
+    sSavedXulAppFile = Smprintf("%s=%s", "XUL_APP_FILE", s).release();
+    MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(sSavedXulAppFile);
+  }
+}
+
+const char* AppShutdown::GetObserverKey(ShutdownPhase aPhase) {
+  return sPhaseObserverKeys[static_cast<std::underlying_type_t<ShutdownPhase>>(
+      aPhase)];
+}
+
+const char* AppShutdown::GetShutdownPhaseName(ShutdownPhase aPhase) {
+  return sPhaseReadableNames[static_cast<std::underlying_type_t<ShutdownPhase>>(
+      aPhase)];
+}
+
+void AppShutdown::MaybeDoRestart() {
+  if (sShutdownMode == AppShutdownMode::Restart) {
+    StopLateWriteChecks();
+
+    // Since we'll be launching our child while we're still alive, make sure
+    // we've unlocked the profile first, otherwise the child could hit its
+    // profile lock check before we've exited and thus released our lock.
+    UnlockProfile();
+
+    if (sSavedXulAppFile) {
+      PR_SetEnv(sSavedXulAppFile);
+    }
+
+#ifdef XP_WIN
+    if (sSavedProfDEnvVar && !EnvHasValue("XRE_PROFILE_PATH")) {
+      SetEnvironmentVariableW(L"XRE_PROFILE_PATH", sSavedProfDEnvVar);
+    }
+    if (sSavedProfLDEnvVar && !EnvHasValue("XRE_PROFILE_LOCAL_PATH")) {
+      SetEnvironmentVariableW(L"XRE_PROFILE_LOCAL_PATH", sSavedProfLDEnvVar);
+    }
+    Unused << NotePreXULSkeletonUIRestarting();
+#else
+    if (sSavedProfDEnvVar && !EnvHasValue("XRE_PROFILE_PATH")) {
+      PR_SetEnv(sSavedProfDEnvVar);
+    }
+    if (sSavedProfLDEnvVar && !EnvHasValue("XRE_PROFILE_LOCAL_PATH")) {
+      PR_SetEnv(sSavedProfLDEnvVar);
+    }
+#endif
+
+    LaunchChild(true);
+  }
+}
+
+#ifdef XP_WIN
+wchar_t* CopyPathIntoNewWCString(nsIFile* aFile) {
+  wchar_t* result = nullptr;
+  nsAutoString resStr;
+  aFile->GetPath(resStr);
+  if (resStr.Length() > 0) {
+    result = (wchar_t*)malloc((resStr.Length() + 1) * sizeof(wchar_t));
+    if (result) {
+      wcscpy(result, resStr.get());
+      result[resStr.Length()] = 0;
+    }
+  }
+
+  return result;
+}
+#endif
+
+void AppShutdown::Init(AppShutdownMode aMode, int aExitCode) {
+  if (sShutdownMode == AppShutdownMode::Normal) {
+    sShutdownMode = aMode;
+  }
+
+  sExitCode = aExitCode;
+
+#ifndef ANDROID
+  sTerminator = new nsTerminator();
+#endif
+
+  // Late-write checks needs to find the profile directory, so it has to
+  // be initialized before services::Shutdown or (because of
+  // xpcshell tests replacing the service) modules being unloaded.
+  InitLateWriteChecks();
+
+  int32_t fastShutdownPref = StaticPrefs::toolkit_shutdown_fastShutdownStage();
+  sFastShutdownPhase = GetShutdownPhaseFromPrefValue(fastShutdownPref);
+  int32_t lateWriteChecksPref =
+      StaticPrefs::toolkit_shutdown_lateWriteChecksStage();
+  sLateWriteChecksPhase = GetShutdownPhaseFromPrefValue(lateWriteChecksPref);
+
+  // Very early shutdowns can happen before the startup cache is even
+  // initialized; don't bother initializing it during shutdown.
+  if (auto* cache = scache::StartupCache::GetSingletonNoInit()) {
+    cache->MaybeInitShutdownWrite();
+  }
+}
+
+void AppShutdown::MaybeFastShutdown(ShutdownPhase aPhase) {
+  // For writes which we want to ensure are recorded, we don't want to trip
+  // the late write checking code. Anything that writes to disk and which
+  // we don't want to skip should be listed out explicitly in this section.
+  if (aPhase == sFastShutdownPhase || aPhase == sLateWriteChecksPhase) {
+    if (auto* cache = scache::StartupCache::GetSingletonNoInit()) {
+      cache->EnsureShutdownWriteComplete();
+    }
+
+    nsresult rv;
+#ifdef MOZ_NEW_XULSTORE
+    rv = XULStore::Shutdown();
+    NS_ASSERTION(NS_SUCCEEDED(rv), "XULStore::Shutdown() failed.");
+#endif
+
+    nsCOMPtr<nsICertStorage> certStorage =
+        do_GetService("@mozilla.org/security/certstorage;1", &rv);
+    if (NS_SUCCEEDED(rv)) {
+      SpinEventLoopUntil("AppShutdown::MaybeFastShutdown"_ns, [&]() {
+        int32_t remainingOps;
+        nsresult rv = certStorage->GetRemainingOperationCount(&remainingOps);
+        NS_ASSERTION(NS_SUCCEEDED(rv),
+                     "nsICertStorage::getRemainingOperationCount failed during "
+                     "shutdown");
+        return NS_FAILED(rv) || remainingOps <= 0;
+      });
+    }
+  }
+  if (aPhase == sFastShutdownPhase) {
+    StopLateWriteChecks();
+    RecordShutdownEndTimeStamp();
+    MaybeDoRestart();
+
+    profiler_shutdown(IsFastShutdown::Yes);
+
+    DoImmediateExit(sExitCode);
+  } else if (aPhase == sLateWriteChecksPhase) {
+#ifdef XP_MACOSX
+    OnlyReportDirtyWrites();
+#endif /* XP_MACOSX */
+    BeginLateWriteChecks();
+  }
+}
+
+void AppShutdown::OnShutdownConfirmed() {
+  // If we're restarting, we need to save environment variables correctly
+  // while everything is still alive to do so.
+  if (sShutdownMode == AppShutdownMode::Restart) {
+    nsCOMPtr<nsIFile> profD;
+    nsCOMPtr<nsIFile> profLD;
+    NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(profD));
+    NS_GetSpecialDirectory(NS_APP_USER_PROFILE_LOCAL_50_DIR,
+                           getter_AddRefs(profLD));
+#ifdef XP_WIN
+    sSavedProfDEnvVar = CopyPathIntoNewWCString(profD);
+    sSavedProfLDEnvVar = CopyPathIntoNewWCString(profLD);
+#else
+    nsAutoCString profDStr;
+    profD->GetNativePath(profDStr);
+    sSavedProfDEnvVar =
+        Smprintf("XRE_PROFILE_PATH=%s", profDStr.get()).release();
+    nsAutoCString profLDStr;
+    profLD->GetNativePath(profLDStr);
+    sSavedProfLDEnvVar =
+        Smprintf("XRE_PROFILE_LOCAL_PATH=%s", profLDStr.get()).release();
+#endif
+    MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(sSavedProfDEnvVar);
+    MOZ_LSAN_INTENTIONALLY_LEAK_OBJECT(sSavedProfLDEnvVar);
+  }
+}
+
+void AppShutdown::DoImmediateExit(int aExitCode) {
+#ifdef XP_WIN
+  HANDLE process = ::GetCurrentProcess();
+  if (::TerminateProcess(process, aExitCode)) {
+    ::WaitForSingleObject(process, INFINITE);
+  }
+  MOZ_CRASH("TerminateProcess failed.");
+#else
+  _exit(aExitCode);
+#endif
+}
+
+bool AppShutdown::IsRestarting() {
+  return sShutdownMode == AppShutdownMode::Restart;
+}
+
+#ifdef DEBUG
+static bool sNotifyingShutdownObservers = false;
+static bool sAdvancingShutdownPhase = false;
+
+bool AppShutdown::IsNoOrLegalShutdownTopic(const char* aTopic) {
+  if (!XRE_IsParentProcess()) {
+    // Until we know what to do with AppShutdown for child processes,
+    // we ignore them for now. See bug 1697745.
+    return true;
+  }
+  ShutdownPhase phase = GetShutdownPhaseFromTopic(aTopic);
+  return phase == ShutdownPhase::NotInShutdown ||
+         (sNotifyingShutdownObservers && phase == sCurrentShutdownPhase);
+}
+#endif
+
+void AppShutdown::AdvanceShutdownPhaseInternal(
+    ShutdownPhase aPhase, bool doNotify, const char16_t* aNotificationData,
+    const nsCOMPtr<nsISupports>& aNotificationSubject) {
+  AssertIsOnMainThread();
+#ifdef DEBUG
+  // Prevent us from re-entrance
+  MOZ_ASSERT(!sAdvancingShutdownPhase);
+  sAdvancingShutdownPhase = true;
+  auto exit = MakeScopeExit([] { sAdvancingShutdownPhase = false; });
+#endif
+
+  // We ensure that we can move only forward. We cannot
+  // MOZ_ASSERT here as there are some tests that fire
+  // notifications out of shutdown order.
+  // See for example test_sss_sanitizeOnShutdown.js
+  if (sCurrentShutdownPhase >= aPhase) {
+    return;
+  }
+
+  nsCOMPtr<nsIThread> thread = do_GetCurrentThread();
+
+  // AppShutdownConfirmed is special in some ways as
+  // - we can be called on top of a nested event loop (and it is the phase for
+  //   which SpinEventLoopUntilOrQuit breaks, so we want to return soon)
+  // - we can be called from a sync marionette function that wants immediate
+  //   feedback, too
+  // - in general, AppShutdownConfirmed will fire the "quit-application"
+  //   notification which in turn will cause an event to be dispatched that
+  //   runs all the rest of our shutdown sequence which we do not want to be
+  //   processed on top of the running event.
+  // Thus we never do any NS_ProcessPendingEvents for it.
+  bool mayProcessPending = (aPhase > ShutdownPhase::AppShutdownConfirmed);
+
+  // Give runnables dispatched between two calls to AdvanceShutdownPhase
+  // a chance to run before actually advancing the phase. As we excluded
+  // AppShutdownConfirmed above we can be sure that the processing is
+  // covered by the terminator's timer of the previous phase during normal
+  // shutdown (except out-of-order calls from some test).
+  // Note that this affects only main thread runnables, such that the correct
+  // way of ensuring shutdown processing remains to have an async shutdown
+  // blocker.
+  if (mayProcessPending && thread) {
+    NS_ProcessPendingEvents(thread);
+  }
+
+  // From now on any IsInOrBeyond checks will find the new phase set.
+  sCurrentShutdownPhase = aPhase;
+
+#ifndef ANDROID
+  if (sTerminator) {
+    sTerminator->AdvancePhase(aPhase);
+  }
+#endif
+
+  AppShutdown::MaybeFastShutdown(aPhase);
+
+  // This will null out the gathered pointers for this phase synchronously.
+  // Note that we keep the old order here to avoid breakage, so be aware that
+  // the notifications fired below will find these already cleared in case
+  // you expected the opposite.
+  mozilla::KillClearOnShutdown(aPhase);
+
+  // Empty our MT event queue to process any side effects thereof.
+  if (mayProcessPending && thread) {
+    NS_ProcessPendingEvents(thread);
+  }
+
+  if (doNotify) {
+    const char* aTopic = AppShutdown::GetObserverKey(aPhase);
+    if (aTopic) {
+      nsCOMPtr<nsIObserverService> obsService =
+          mozilla::services::GetObserverService();
+      if (obsService) {
+#ifdef DEBUG
+        sNotifyingShutdownObservers = true;
+        auto reset = MakeScopeExit([] { sNotifyingShutdownObservers = false; });
+#endif
+        obsService->NotifyObservers(aNotificationSubject, aTopic,
+                                    aNotificationData);
+        // Empty our MT event queue again after the notification has finished
+        if (mayProcessPending && thread) {
+          NS_ProcessPendingEvents(thread);
+        }
+      }
+    }
+  }
+}
+
+/**
+ * XXX: Before tackling bug 1697745 we need the
+ * possibility to advance the phase without notification
+ * in the content process.
+ */
+void AppShutdown::AdvanceShutdownPhaseWithoutNotify(ShutdownPhase aPhase) {
+  AdvanceShutdownPhaseInternal(aPhase, /* doNotify */ false, nullptr, nullptr);
+}
+
+void AppShutdown::AdvanceShutdownPhase(
+    ShutdownPhase aPhase, const char16_t* aNotificationData,
+    const nsCOMPtr<nsISupports>& aNotificationSubject) {
+  AdvanceShutdownPhaseInternal(aPhase, /* doNotify */ true, aNotificationData,
+                               aNotificationSubject);
+}
+
+ShutdownPhase AppShutdown::GetShutdownPhaseFromTopic(const char* aTopic) {
+  for (size_t i = 0; i < ArrayLength(sPhaseObserverKeys); ++i) {
+    if (sPhaseObserverKeys[i] && !strcmp(sPhaseObserverKeys[i], aTopic)) {
+      return static_cast<ShutdownPhase>(i);
+    }
+  }
+  return ShutdownPhase::NotInShutdown;
+}
+
+}  // namespace mozilla