#10683 NORM Not Tri: Sugar crashes when an activity creates/destroys windows quickly

[Zarro Boogs per Child]

#10683: Sugar crashes when an activity creates/destroys windows quickly
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 Reporter:  martin.langhoff  |                 Owner:  martin.langhoff                        
     Type:  defect           |                Status:  new                                    
 Priority:  normal           |             Milestone:  Not Triaged                            
Component:  sugar            |               Version:  1.5/1.0 Software Build os860 aka 10.1.3
 Keywords:                   |           Next_action:  never set                              
 Verified:  0                |   Deployment_affected:                                         
Blockedby:                   |              Blocking:                                         
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 When an activity creates/destroys windows quickly, and the windows are
 identified correctly so that they trigger _window_opened_cb(), we have
 race conditions between the test for a valid wnd handle, and querying the
 window.

 When the window is destroyed right after getting the window handle, but
 before we query it, Sugar crashes. shell.log shows a BadWindow error.

 This problem has been spotted with an AdobeAIR application that uses
 libsugarize.so .

  * Thanks to libsugarize, the windows have the right name/class so they
 trigger the callback. Removing libsugarize avoids the crash, but then the
 window is not recognized.
  * This AdobeAIR app goes through 4 windows quickly during startup. This
 can be seen in debug mode -- the callback is triggered 4 times. We are
 investigating with the developer whether this can be avoided. It may be
 that the code uses "loader" SWF files; or it may be that the AdobeAIR
 runtime is coded to create/destroy windows during startup.

 It seems impossible to completely close the race condition (at least at
 the python layer), but additional checks and minor code changes in sugar
 and sugar-toolkit can narrow down the window significantly.

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Ticket URL: <http://dev.laptop.org/ticket/10683>
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