xpcom/base/AppShutdown.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef AppShutdown_h
   8 #define AppShutdown_h
   9
  10 #include <type_traits>
  11 #include "nsCOMPtr.h"
  12 #include "nsISupports.h"
  13 #include "ShutdownPhase.h"
  14
  15 namespace mozilla {
  16
  17 enum class AppShutdownMode {
  18   Normal,
  19   Restart,
  20 };
  21
  22 enum class AppShutdownReason {
  23   // No reason.
  24   Unknown,
  25   // Normal application shutdown.
  26   AppClose,
  27   // The application wants to restart.
  28   AppRestart,
  29   // The OS is force closing us.
  30   OSForceClose,
  31   // The user is logging off from the OS session, the system may stay alive.
  32   OSSessionEnd,
  33   // The system is shutting down (and maybe restarting).
  34   OSShutdown,
  35 };
  36
  37 class AppShutdown {
  38  public:
  39   static ShutdownPhase GetCurrentShutdownPhase();
  40   static bool IsInOrBeyond(ShutdownPhase aPhase);
  41
  42   /**
  43    * Returns the current exit code that the process will be terminated with.
  44    */
  45   static int GetExitCode();
  46
  47   /**
  48    * Save environment variables that we might need if the app initiates a
  49    * restart later in its lifecycle.
  50    */
  51   static void SaveEnvVarsForPotentialRestart();
  52
  53   /**
  54    * Init the shutdown with the requested shutdown mode, exit code and optional
  55    * a reason (if missing it will be derived from aMode).
  56    */
  57   static void Init(AppShutdownMode aMode, int aExitCode,
  58                    AppShutdownReason aReason);
  59
  60   /**
  61    * Confirm that we are in fact going to be shutting down.
  62    */
  63   static void OnShutdownConfirmed();
  64
  65   /**
  66    * If we've attempted to initiate a restart, this call will set up the
  67    * necessary environment variables and launch the new process.
  68    */
  69   static void MaybeDoRestart();
  70
  71   /**
  72    * The _exit() call is not a safe way to terminate your own process on
  73    * Windows, because _exit runs DLL detach callbacks which run static
  74    * destructors for xul.dll.
  75    *
  76    * This method terminates the current process without those issues.
  77    *
  78    * Optionally a custom exit code can be supplied.
  79    */
  80   static void DoImmediateExit(int aExitCode = 0);
  81
  82   /**
  83    * True if the application is currently attempting to shut down in order to
  84    * restart.
  85    */
  86   static bool IsRestarting();
  87
  88   /**
  89    * Wrapper for shutdown notifications that informs the terminator before
  90    * we notify other observers. Calls MaybeFastShutdown.
  91    */
  92   static void AdvanceShutdownPhase(
  93       ShutdownPhase aPhase, const char16_t* aNotificationData = nullptr,
  94       const nsCOMPtr<nsISupports>& aNotificationSubject =
  95           nsCOMPtr<nsISupports>(nullptr));
  96
  97   /**
  98    * XXX: Before tackling bug 1697745 we need the
  99    * possibility to advance the phase without notification
 100    * in the content process.
 101    */
 102   static void AdvanceShutdownPhaseWithoutNotify(ShutdownPhase aPhase);
 103
 104   /**
 105    * Map shutdown phase to observer key
 106    */
 107   static const char* GetObserverKey(ShutdownPhase aPhase);
 108
 109   /**
 110    * Map shutdown phase to readable name
 111    */
 112   static const char* GetShutdownPhaseName(ShutdownPhase aPhase);
 113
 114   /**
 115    * Map observer topic key to shutdown phase
 116    */
 117   static ShutdownPhase GetShutdownPhaseFromTopic(const char* aTopic);
 118
 119 #ifdef DEBUG
 120   /**
 121    * Check, if we are allowed to send a shutdown notification.
 122    * Shutdown specific topics are only allowed during calls to
 123    * AdvanceShutdownPhase itself.
 124    */
 125   static bool IsNoOrLegalShutdownTopic(const char* aTopic);
 126 #endif
 127
 128  private:
 129   /**
 130    * Set the shutdown reason annotation.
 131    */
 132   static void AnnotateShutdownReason(AppShutdownReason aReason);
 133
 134   /**
 135    * This will perform a fast shutdown via _exit(0) or similar if the user's
 136    * prefs are configured to do so at this phase.
 137    */
 138   static void MaybeFastShutdown(ShutdownPhase aPhase);
 139
 140   /**
 141    * Internal helper function, uses MaybeFastShutdown.
 142    */
 143   static void AdvanceShutdownPhaseInternal(
 144       ShutdownPhase aPhase, bool doNotify, const char16_t* aNotificationData,
 145       const nsCOMPtr<nsISupports>& aNotificationSubject);
 146 };
 147
 148 }  // namespace mozilla
 149
 150 #endif  // AppShutdown_h