[GRASS-dev] Re: [GRASS GIS] #226: WinGRASS fails to create .gislock opening a mapset

GRASS GIS trac at osgeo.org
Tue Jan 3 09:14:28 EST 2012

#226: WinGRASS fails to create .gislock opening a mapset
 Reporter:  msieczka        |       Owner:  grass-dev@…              
     Type:  defect          |      Status:  new                      
 Priority:  major           |   Milestone:  6.4.2                    
Component:  Default         |     Version:  svn-develbranch6         
 Keywords:  wingrass, qgis  |    Platform:  MSWindows XP             
      Cpu:  All             |  

Comment(by mmetz):

 Replying to [comment:18 glynn]:
 > Replying to [comment:17 mmetz]:
 > > The check for the state of a lock file should return one of three
 answers: is valid, can't say, is stale. The lock file is (should be)
 removed if stale, if its status is unknown, user-interaction is probably
 the only option.
 > The main requirement for this is that the lock file needs to contain
 both the host and the PID. As for the check: if the host is not the local
 system, the status is unknown, otherwise the lock file is considered live
 if the PID exists and stale otherwise. False positives can be reduced by
 testing for the PID twice with a delay in between.

 Sounds good to me. If the host is not the local system, the status is
 unknown, but (most of the time) it should be safe to assume that the lock
 is alive and not stale.
 > Having the PID in the lock file is the only way that an "obviously
 stale" lock file can be detected and overridden automatically. Without
 that, any lock file must be assumed to be live, with any override
 requiring user involvement.

 This is what we probably have to settle for with windows and lock files
 created from different hosts.
 > Storing the user in the lock file is harmless but redundant. The user
 stored in the lock file will always be the user who owns both the mapset
 directory and the .gislock file. The start-up code won't let you select a
 mapset which you do not own as the current mapset.

 Ah ok, I thought write permission suffices.

 Markus M

Ticket URL: <https://trac.osgeo.org/grass/ticket/226#comment:20>
GRASS GIS <http://grass.osgeo.org>

More information about the grass-dev mailing list