609260 - sessionstore.js is written so late that session is not (properly) saved

Status: RESOLVED WONTFIX

(Firefox :: Session Restore, defect)

Description

[Stefan]

User-Agent:       Mozilla/5.0 (X11; Linux x86_64; rv:2.0b8pre) Gecko/20100101 Firefox/4.0b8pre
Build Identifier: Mozilla/5.0 (X11; Linux x86_64; rv:2.0b8pre) Gecko/20100101 Firefox/4.0b8pre

The file sessionstore.js seems to be written a few seconds after the session's state has changed. When the browser crashed during this lag firefox will not recover the last state before the crash.

Reproducible: Always

Steps to Reproduce:
1. monitor the file modification date of sessionstore.js
2. surf the web
3. observe when sessionstore.js's date changes after you change the session's state.

Actual Results:  
There is a delay of some seconds before the current state is written to sessionstore.js.

Expected Results:  
The is no such delay.

Comment 1

[Nickolay_Ponomarev]

There's a tradeoff between saving immediately (which causes a major performance hit) and saving every few seconds (which may lose a few seconds of your browsing).

Comment 2

[Paul O'Shannessy [:zpao] (not bugmail, email directly)]

This is by design. As Nickolay mentioned, there's a tradeoff. Losing at most 15 seconds (by default) of work in the browser is not that bad.

When quitting, we'll save everything, so there shouldn't be a loss of state then, only when crashing.

Comment 3

[Stefan]

I now encounter a "phantom" window after regularly qutting and restarting FF. It seems that qutting does not necessarily save the state of already closed browser windows.

I'll try to prepare a testcase.

Comment 4

[Stefan]

Attachment: testcase

Comment 5

[Stefan]

Attachment: minimal localstore.rdf to reproduce the issue

Comment 6

[Stefan]

I found out that certain values in localstore.rdf caused the windows to "hang" after a restart.

1. Start with fresh profile. 
2. Disable default browser checks.
3. Select "Show my windows and tabs from last time."
4. Open testcase. Allow Popups for bug...
5. Finish FF
6. Copy localstore.rdf into profile folder.
7. Restart FF. (-> page is loaded, windows pop up and disappear).
8. Close FF immediately.
9. Restart FF. (-> same a 7, but windows hang).

Sorry for that lengthy testcase.

Comment 7

[Teodosia Pop]

There is an option to save your session more frequently. In about:config, you can set browser.sessionstore.interval to another value. The interval is specified in milliseconds and to reduce it simply enter a smaller value.

What to you mean by "2. Disable default browser checks." in comment 6?

Comment 8

[Stefan]

In "There is no such delay" I do not expect something to be done "more frequently". I would like to see the URL in the session store always BEFORE FF crashes. (MF/FF crash extremely rarely)

How is that dialog named which informs about FF not being the operating systems default browser?

Comment 9

[Wayne Mery (:wsmwk)]

Stefan, 

per zpao " if stefan can still reproduce [using Firefox 7 or newer] then i'm interested (though the bug as originally reported should be wontfix)"

Comment 10

[Stefan]

I can't reproduce comment #6 step 9 hang with nightly 2011-10-11-03-10-00-mozilla-central.

Comment 11

[Wayne Mery (:wsmwk)]

thanks for the update.