Problem with WIN 7, UAC and IE8

Yearling · 2010-05-14 08:37

I have problem with last beta version Shutter (May 2, 2010) on WIN7. Shutter works OK but when I try to open IE8, IE crashes with error message "Exception EMutexLockError in module Inactivity.dll at 0000848E. Failed to create mutex."

This problem appear when User Account Control is on default level - when User Account Control is OFF, everything is OK.

On the previous beta version this problem didn't appear, but there countdown of inactivity didn't work correctly (http://www.den4b.com/forum/viewtopic.php?id=874).

den4b · 2010-05-14 12:43

The code that raises the error is to do with thread safety procedures for using inactivity library, which were implemented only recently. It seems that increased security measures in Win 7 block those procedures. I have implemented some improvements which should help either by eliminating the problem or by producing a more descriptive error message.

Unfortunately I can't test it because I don't have Win 7. Let me know how it goes.

Yearling · 2010-05-14 16:30

New beta = the same results as previous but with a small different errormessage:
"Exception EMutexLockError in module Inactivity.dll at 00008554. Failed to create mutex."

den4b · 2010-05-14 19:53

I made another attempt. Try latest beta version and make sure that version of Inactivity.dll reads 1.0.0.10 (you can find this information in Properties by right-clicking on the file). If an error occurs please paste the whole message, it should be longer than what you had so far.

If this fails to work to too - it's a dead end. I'll just have to switch off thread safety procedures for Windows 7.

Yearling · 2010-05-14 22:12

Version of Inactivity.dll is 1.0.0.10
This version seems to be good on first look - now IE8 works OK but there is another small bug: counter of user inactivity doesn't work - it is still 0:00:00

den4b · 2010-05-15 02:28

After several hours of digging around MSDN and experimenting I finally got to the bottom of this. Inactivity library is based on usage of system-wide hooks, shared memory and code injection to monitor user inactivity. These techniques have been made a nightmare to work with and in many cases impossible to implement on latest versions of Windows (Vista and 7) due to security restrictions.

While I was figuring out workarounds for those techniques I found an alternative and a much better way for tracking user inactivity. No more hooks, shared memory and code injection. This alternative method can be used on Windows 2000 and higher, while Inactivity library will be used for prior versions of Windows.

You can try it from here: ShutterBeta.zip

P.S. Regarding the error you got, it seems that IE8 under Vista/7 is launched by some system service which effectively gives it security and session properties different to the ones Shutter has, which breaks interprocess communications between injected code and Shutter.

Yearling · 2010-05-15 19:25

I am still testing it but I think everything work good now.
Thank you very much for your help.

den4b Forum

#1 2010-05-14 08:37

Problem with WIN 7, UAC and IE8

#2 2010-05-14 12:43

Re: Problem with WIN 7, UAC and IE8

#3 2010-05-14 16:30

Re: Problem with WIN 7, UAC and IE8

#4 2010-05-14 19:53

Re: Problem with WIN 7, UAC and IE8

#5 2010-05-14 22:12

Re: Problem with WIN 7, UAC and IE8

#6 2010-05-15 02:28

Re: Problem with WIN 7, UAC and IE8

#7 2010-05-15 19:25

Re: Problem with WIN 7, UAC and IE8

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