gecko-dev/widget/nsAppShellSingleton.h
Nathan Froyd 2257f3e1ae Bug 1545381 - be more defensive in nsAppShellSingleton; r=erahm
We're seeing crashes in bug 1545381 in appshell shutdown, which appear
to point to appshell initialization somehow falling over non-obviously.
Appshell initialization should basically never fail, so let's complain
loudly if that ever happens.

Differential Revision: https://phabricator.services.mozilla.com/D38915

--HG--
extra : moz-landing-system : lando
2019-07-22 20:52:35 +00:00

63 lines
2.1 KiB
C

/* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; -*- */
/* 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/. */
#ifndef nsAppShellSingleton_h__
#define nsAppShellSingleton_h__
/**
* This file is designed to be included into the file that provides the
* nsIModule implementation for a particular widget toolkit.
*
* The following functions are defined:
* nsAppShellInit
* nsAppShellShutdown
* nsAppShellConstructor
*
* The nsAppShellInit function is designed to be used as a module constructor.
* If you already have a module constructor, then call nsAppShellInit from your
* module constructor.
*
* The nsAppShellShutdown function is designed to be used as a module
* destructor. If you already have a module destructor, then call
* nsAppShellShutdown from your module destructor.
*
* The nsAppShellConstructor function is designed to be used as a factory
* method for the nsAppShell class.
*/
#include "nsXULAppAPI.h"
static nsIAppShell* sAppShell;
static nsresult nsAppShellInit() {
NS_ASSERTION(!sAppShell, "already initialized");
sAppShell = new nsAppShell();
if (!sAppShell) return NS_ERROR_OUT_OF_MEMORY;
NS_ADDREF(sAppShell);
nsresult rv = static_cast<nsAppShell*>(sAppShell)->Init();
// If we somehow failed to initialize the appshell, it's extremely likely
// that we are sufficiently hosed that continuing on is just going to lead
// to bad things later. By crashing early here, the crash report will
// potentially contain a little more insight into what's going wrong than
// if we waited for a crash further down the line. See also bug 1545381.
MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
return NS_OK;
}
static void nsAppShellShutdown() { NS_RELEASE(sAppShell); }
nsresult nsAppShellConstructor(nsISupports* outer, const nsIID& iid,
void** result) {
NS_ENSURE_TRUE(!outer, NS_ERROR_NO_AGGREGATION);
NS_ENSURE_TRUE(sAppShell, NS_ERROR_NOT_INITIALIZED);
return sAppShell->QueryInterface(iid, result);
}
#endif // nsAppShellSingleton_h__