[GRASS-dev] [GRASS GIS] #2230: 'g.region -p' writes new WIND file, causes race condition for parallel jobs

[GRASS GIS]

#2230: 'g.region -p' writes new WIND file, causes race condition for parallel jobs
----------------------+-----------------------------------------------------
 Reporter:  hamish    |       Owner:  grass-dev@…              
     Type:  defect    |      Status:  new                      
 Priority:  normal    |   Milestone:  6.4.4                    
Component:  Default   |     Version:  svn-develbranch6         
 Keywords:  g.region  |    Platform:  Linux                    
      Cpu:  x86-64    |  
----------------------+-----------------------------------------------------
 Hi,

 In tracking down some strangeness I've just noticed that 'g.region -p' or
 'g.region -g' writes out a new (unchanged) WIND file whenever it runs.

 This is a problem when you have many jobs working in parallel and a bunch
 of them starting at the same time all call 'eval `g.region -g`' at the
 start of their scripts. About 5% of the time I'm hitting the file before
 it is completely written and the unfortunate g.region G_fatal_error()s
 with a missing projection parameter or similar.

 one solution is to not open the WIND file for writing if just read-only
 command line terms are given, another is to write to a .tmp file and move
 it into place atomically.


 Hamish

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/2230>
GRASS GIS <http://grass.osgeo.org>