[or-cvs] r15161: Notes on the problem with multiple Firefoxes (torbrowser/trunk/docs)

[sjm217 at seul.org]

Author: sjm217
Date: 2008-06-12 08:55:06 -0400 (Thu, 12 Jun 2008)
New Revision: 15161

Added:
   torbrowser/trunk/docs/two-firefox.txt
Log:
Notes on the problem with multiple Firefoxes

Added: torbrowser/trunk/docs/two-firefox.txt
===================================================================
--- torbrowser/trunk/docs/two-firefox.txt	                        (rev 0)
+++ torbrowser/trunk/docs/two-firefox.txt	2008-06-12 12:55:06 UTC (rev 15161)
@@ -0,0 +1,72 @@
+###
+### Notes on problems running two Firefox instances in parallel
+###
+### Steven J. Murdoch <http://www.cl.cam.ac.uk/users/sjm217/>
+###
+### $Id$
+###
+
+Introduction
+============
+
+It sometimes might be desirable to have multiple instances of Tor
+running simultaneously, for example using one for normal web browsing
+and one for Tor.
+
+Firefox does not support this very well, under Windows, and therefore
+FirefoxPortable will by default prevent multiple instances of Firefox.
+
+There are two scenarios in which multiple instances of Firefox will
+run: Tor Browser starting first and Tor Browser starting second. Since
+we only have control of the Tor Browser configuration, the two
+scenarios are difference.
+
+Tor Browser starting first
+==========================
+
+If Firefox is not running when Tor Browser is started, FirefoxPortable
+will launch Firefox as normal.
+
+When the second Firefox is launched, it will search for existing
+Firefox windows:
+ http://lxr.mozilla.org/mozilla1.8.0/source/xpfe/bootstrap/nsNativeAppSupportWin.cpp#1060
+
+If an existing instance is found, Firefox will open a new Window, so
+the end result is two Torifed Firefox windows.
+
+Tor Browser starting second
+===========================
+
+If Firefox is already running when Tor Browser is launched,
+FirefoxPortable will abort the startup unless the
+AllowMultipleInstances FirefoxPortable option is set.
+
+In that case, the MOZ_NO_REMOTE environment variable will be set,
+which will cause Firefox not to search for existing Firefox windows,
+and so launch a separate instance.
+
+MOZ_NO_REMOTE appears to also disable the creation of a messaging
+window, so will also handle the case of Tor Browser starting first. If
+this is not the case, an extension to the Torbutton addon can have the
+same effect.
+
+Problems with AllowMultipleInstances
+====================================
+
+The AllowMultipleInstances option is close to what is needed, but
+there are two main problems.
+
+The first problem is that enabling the option will disable some of the
+FirefoxPortable cleanup code. From initial tests, this does not appear
+to leave any additional traces, but more investigation is needed.
+
+The second, and more serious problem, is that enabling the option
+conflicts with WaitForFirefox option. This means that the first time
+Tor Browser Bundle is run, FirefoxPortable will open a Firefox window
+and exit, causing Vidalia to exit too. This occurs even if
+WaitForFirefox is true. When FirefoxPortable is run a second time, it
+starts as normal.
+
+This is probably a bug in FirefoxPortable, and needs to be
+investigated further. If fixed, it looks likely that it will be
+possible to have multiple instances of Firefox


Property changes on: torbrowser/trunk/docs/two-firefox.txt
___________________________________________________________________
Name: svn:keywords
   + Id
Name: svn:eol-style
   + native