• Arnaud Fontaine's avatar
    ZODB Components: Modules loaded by one Request were being GC'ed while executing in another Request. · f523edc4
    Arnaud Fontaine authored
    Until this commit, loading a ZODB Component would add it to the current Request
    object to prevent its reference counter reaching 0 (thus its global being reset to
    None and then being later GC'ed) when a reset happens in another Request.
    
    This problem was found when investigating testFunctionalConfigurator failure
    when installing bt5s as requested by the Configurator:
      1. Request R1 calls Zuite_waitForActivities importing extension.erp5.ERP5Zuite (M1).
         => Add M1 to R1._module_cache_set.
         => M1 ref counter equals to 2 (sys.modules and R1._module_cache_set references).
      2. R1 terminates and is GC'ed.
         => M1 ref counter equals to 1 (sys.modules).
      3. Request R2 runs Configurator configuring the Site.
      4. testFunctionalConfigurator calls Zuite_waitForActivities to wait for the
         Configurator to finish (request R3 which may take ~15 minutes). This calls
         time.sleep() in a loop where 'time' module is imported at top-level.
      5. R2 installs bt5 triggering reset.
         => M1 ref counter equals to 0.
            ===> M1 global variables are reset to None and thus 'time' is set to None
                 raising an Exception in the next call of time.sleep() in the loop.
    
    The easiest way would be to have a hook on sys.modules dict lookup and thus add M1
    to R2._module_cache_set when being imported, but this is not supported... Instead
    create a global cache on erp5.component package.
    f523edc4
testBusinessTemplate.py 350 KB